]> CopyrightCopyright © 1985-2007 by the Massachusetts Institute of Technology. Export of software employing encryption from the United States of America may require a specific license from the United States Government. It is the responsibility of any person or organization contemplating export to obtain such a license before exporting. WITHIN THAT CONSTRAINT, permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of M.I.T. not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. Furthermore if you modify this software you must label your software as modified software and not distribute it in such a fashion that it might be confused with the original MIT software. M.I.T. makes no representations about the suitability of this software for any purpose. It is provided “as is” without express or implied warranty. Individual source code files are copyright MIT, Cygnus Support, Novell, OpenVision Technologies, Oracle, Red Hat, Sun Microsystems, FundsXpress, and others. Project Athena, Athena, Athena MUSE, Discuss, Hesiod, Kerberos, Moira, and Zephyr are trademarks of the Massachusetts Institute of Technology (MIT). No commercial use of these trademarks may be made without prior written permission of MIT. “Commercial use” means use of a name in a product or other for-profit manner. It does NOT prevent a commercial firm from referring to the MIT trademarks in order to convey information (although in doing so, recognition of their trademark status should be given). The following copyright and permission notice applies to the OpenVision Kerberos Administration system located in kadmin/create, kadmin/dbutil, kadmin/passwd, kadmin/server, lib/kadm5, and portions of lib/rpc: Copyright, OpenVision Technologies, Inc., 1996, All Rights Reserved WARNING: Retrieving the OpenVision Kerberos Administration system source code, as described below, indicates your acceptance of the following terms. If you do not agree to the following terms, do not retrieve the OpenVision Kerberos administration system. You may freely use and distribute the Source Code and Object Code compiled from it, with or without modification, but this Source Code is provided to you “AS IS” EXCLUSIVE OF ANY WARRANTY, INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, OR ANY OTHER WARRANTY, WHETHER EXPRESS OR IMPLIED. IN NO EVENT WILL OPENVISION HAVE ANY LIABILITY FOR ANY LOST PROFITS, LOSS OF DATA OR COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, INCLUDING, WITHOUT LIMITATION, THOSE RESULTING FROM THE USE OF THE SOURCE CODE, OR THE FAILURE OF THE SOURCE CODE TO PERFORM, OR FOR ANY OTHER REASON. OpenVision retains all copyrights in the donated Source Code. OpenVision also retains copyright to derivative works of the Source Code, whether created by OpenVision or by a third party. The OpenVision copyright notice must be preserved if derivative works are made based on the donated Source Code. OpenVision Technologies, Inc. has donated this Kerberos Administration system to MIT for inclusion in the standard Kerberos 5 distribution. This donation underscores our commitment to continuing Kerberos technology development and our gratitude for the valuable work which has been performed by MIT and the Kerberos community. Portions contributed by Matt Crawford <crawdad@fnal.gov> were work performed at Fermi National Accelerator Laboratory, which is operated by Universities Research Association, Inc., under contract DE-AC02-76CHO3000 with the U.S. Department of Energy. Portions of src/lib/crypto have the following copyright: Copyright © 1998 by the FundsXpress, INC. All rights reserved. Export of this software from the United States of America may require a specific license from the United States Government. It is the responsibility of any person or organization contemplating export to obtain such a license before exporting. WITHIN THAT CONSTRAINT, permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of FundsXpress. not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. FundsXpress makes no representations about the suitability of this software for any purpose. It is provided “as is” without express or implied warranty. THIS SOFTWARE IS PROVIDED “AS IS” AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. The implementation of the Yarrow pseudo-random number generator in src/lib/crypto/yarrow has the following copyright: Copyright 2000 by Zero-Knowledge Systems, Inc. Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Zero-Knowledge Systems, Inc. not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. Zero-Knowledge Systems, Inc. makes no representations about the suitability of this software for any purpose. It is provided “as is” without express or implied warranty. ZERO-KNOWLEDGE SYSTEMS, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL ZERO-KNOWLEDGE SYSTEMS, INC. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTUOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. The implementation of the AES encryption algorithm in src/lib/crypto/aes has the following copyright: Copyright © 2001, Dr Brian Gladman <brg@gladman.uk.net>, Worcester, UK. All rights reserved. LICENSE TERMS The free distribution and use of this software in both source and binary form is allowed (with or without changes) provided that: distributions of this source code include the above copyright notice, this list of conditions and the following disclaimer; distributions in binary form include the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other associated materials; the copyright holder's name is not used to endorse products built using this software without specific written permission. DISCLAIMER This software is provided 'as is' with no explcit or implied warranties in respect of any properties, including, but not limited to, correctness and fitness for purpose. Portions contributed by Red Hat, including the pre-authentication plug-in framework, contain the following copyright: Copyright © 2006 Red Hat, Inc. Portions copyright © 2006 Massachusetts Institute of Technology All Rights Reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of Red Hat, Inc., nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. The implementations of GSSAPI mechglue in GSSAPI-SPNEGO in src/lib/gssapi, including the following files: lib/gssapi/generic/gssapi_err_generic.et lib/gssapi/mechglue/g_accept_sec_context.c lib/gssapi/mechglue/g_acquire_cred.c lib/gssapi/mechglue/g_canon_name.c lib/gssapi/mechglue/g_compare_name.c lib/gssapi/mechglue/g_context_time.c lib/gssapi/mechglue/g_delete_sec_context.c lib/gssapi/mechglue/g_dsp_name.c lib/gssapi/mechglue/g_dsp_status.c lib/gssapi/mechglue/g_dup_name.c lib/gssapi/mechglue/g_exp_sec_context.c lib/gssapi/mechglue/g_export_name.c lib/gssapi/mechglue/g_glue.c lib/gssapi/mechglue/g_imp_name.c lib/gssapi/mechglue/g_imp_sec_context.c lib/gssapi/mechglue/g_init_sec_context.c lib/gssapi/mechglue/g_initialize.c lib/gssapi/mechglue/g_inquire_context.c lib/gssapi/mechglue/g_inquire_cred.c lib/gssapi/mechglue/g_inquire_names.c lib/gssapi/mechglue/g_process_context.c lib/gssapi/mechglue/g_rel_buffer.c lib/gssapi/mechglue/g_rel_cred.c lib/gssapi/mechglue/g_rel_name.c lib/gssapi/mechglue/g_rel_oid_set.c lib/gssapi/mechglue/g_seal.c lib/gssapi/mechglue/g_sign.c lib/gssapi/mechglue/g_store_cred.c lib/gssapi/mechglue/g_unseal.c lib/gssapi/mechglue/g_userok.c lib/gssapi/mechglue/g_utils.c lib/gssapi/mechglue/g_verify.c lib/gssapi/mechglue/gssd_pname_to_uid.c lib/gssapi/mechglue/mglueP.h lib/gssapi/mechglue/oid_ops.c lib/gssapi/spnego/gssapiP_spnego.h lib/gssapi/spnego/spnego_mech.c are subject to the following license: Copyright © 2004 Sun Microsystems, Inc. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Kerberos V5 includes documentation and software developed at the University of California at Berkeley, which includes this copyright notice: Copyright © 1983 Regents of the University of California. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of the University nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Portions contributed by Novell, Inc., including the LDAP database backend, are subject to the following license: Copyright (c) 2004-2005, Novell, Inc. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. The copyright holder's name is not used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notices and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions. Introduction Why Should I use Kerberos? Since Kerberos negotiates authenticated, and optionally encrypted, communications between two points anywhere on the internet, it provides a layer of security that is not dependent on which side of a firewall either client is on. Since studies have shown that half of the computer security breaches in industry happen from inside firewalls, Kerberos V5 from MIT will play a vital role in the security of your network. Documentation for Kerberos V5 This document is one piece of the document set for Kerberos V5. The documents, and their intended audiences, are: Kerberos V5 Installation Guide: a concise guide for installingKerberos V5. Kerberos administrators (particularly whoever will bemaking site-wide decisions about the installation) and the systemadministrators who will be installing the software should read thisguide. Kerberos V5 System Administrator's Guide: a sysadmin's guide toadministering a Kerberos installation. The System Administrator's Guidedescribes the administration software and suggests policies andprocedures for administering a Kerberos installation. Anyone who willhave administrative access to your Kerberos database should read thisguide. Kerberos V5 UNIX User's Guide: a guide to using the KerberosUNIX client programs. All users on UNIX systems should read this guide,particularly the “Tutorial” section. Overview of This Guide The next chapter describes how Kerberos works. Chapter three describes administration of the principals in the Kerberos database. Chapter four describes how you can use DNS in configuring your Kerberos realm. Chapter five describes administrative programs for manipulating the Kerberos database as a whole. Chapter six describes OpenLDAP Configuration steps. Chapter seven describes issues to consider when adding an application server to the database. Chapter eight describes our problem reporting system. The appendices include the list of Kerberos error messages, and a complete list of the time zones understood by kadmin. How Kerberos Works This section provides a simplified description of a general user's interaction with the Kerberos system. This interaction happens transparently—users don't need to know and probably don't care about what's going on—but Kerberos administrators might find a schematic description of the process useful. This description glosses over a lot of details; for more information, see Kerberos: An Authentication Service for Open Network Systems, a paper presented at Winter USENIX 1988, in Dallas, Texas. This paper can be retreived by FTP from athena-dist.mit.edu, in the location: /pub/ATHENA/kerberos/doc/usenix.PS. Network Services and Their Client Programs In an environment that provides network services, you use client programs to request services from server programs that are somewhere on the network. Suppose you have logged in to a workstation and you want to ‘rlogin’ to a typical UNIX host. You use the local ‘rlogin’ client program to contact the remote machine's ‘rlogind’ daemon. Kerberos Tickets Under Kerberos, the ‘klogind’ daemon allows you to login to a remote machine if you can provide ‘klogind’ a Kerberos ticket which proves your identity. In addition to the ticket, you must also have possession of the corresponding ticket session key. The combination of a ticket and the ticket's session key is known as a credential. Typically, a client program automatically obtains credentials identifying the person using the client program. The credentials are obtained from a Kerberos server that resides somewhere on the network. A Kerberos server maintains a database of user, server, and password information. The Kerberos Database Kerberos will give you credentials only if you have an entry in the Kerberos server's Kerberos database. Your database entry includes your Kerberos principal (an identifying string, which is often just your username), and your Kerberos password. Every Kerberos user must have an entry in this database. Kerberos Realms Each administrative domain will have its own Kerberos database, which contains information about the users and services for that particular site or administrative domain. This administrative domain is the Kerberos realm. Each Kerberos realm will have at least one Kerberos server, where the master Kerberos database for that site or administrative domain is stored. A Kerberos realm may also have one or more slave servers, which have read-only copies of the Kerberos database that are periodically propagated from the master server. For more details on how this is done, see the “Set Up the Slave KDCs for Database Propagation” and “Propagate the Database to Each Slave KDC” sections of the Kerberos V5 Installation Guide. The Ticket-Granting Ticket The ‘kinit’ command prompts for your password. If you enter it successfully, you will obtain a ticket-granting ticket and a ticket session key which gives you the right to use the ticket. This combination of the ticket and its associated key is known as your credentials. As illustrated below, client programs use your ticket-granting ticket credentials in order to obtain client-specific credentials as needed. Your credentials are stored in a credentials cache, which is often just a file in /tmp. The credentials cache is also called the ticket file, especially in Kerberos V4 documentation. Note, however, that a credentials cache does not have to be stored in a file. Network Services and the Master Database The master database also contains entries for all network services that require Kerberos authentication. Suppose that your site has a machine, ‘laughter.mit.edu’, that requires Kerberos authentication from anyone who wants to ‘rlogin’ to it. The host's Kerberos realm is ‘ATHENA.MIT.EDU’. This service must be registered in the Kerberos database, using the proper service name, which in this case is the principal: host/laughter.mit.edu@ATHENA.MIT.EDU The ‘/’ character separates the Kerberos primary (in this case, ‘host’) from the instance (in this case, ‘laughter.mit.edu’); the ‘@’ character separates the realm name (in this case, ‘ATHENA.MIT.EDU’) from the rest of the principal. The primary, ‘host’, denotes the name or type of the service that is being offered: generic host-level access to the machine. The instance, ‘laughter.mit.edu’, names the specific machine that is offering this service. There will generally be many different machines, each offering one particular type of service, and the instance serves to give each one of these servers a different Kerberos principal. The Keytab File For each service, there must also be a service key known only by Kerberos and the service. On the Kerberos server, the service key is stored in the Kerberos database. On the server host, these service keys are stored in key tables, which are files known as keytabs.Keytabs were called srvtabs in Kerberos V4. For example, the service keys used by services that run as root are usually stored in the keytab file /etc/krb5.keytab. N.B.: This service key is the equivalent of the service's password, and must be kept secure. Data which is meant to be read only by the service is encrypted using this key. The User/Kerberos Interaction Suppose that you walk up to a host intending to login to it, and then ‘rlogin’ to the machine ‘laughter’. Here's what happens: You login to the workstation and use the ‘kinit’ command to get aticket-granting ticket. This command prompts you for your Kerberospassword. (On systems running the Kerberos V5 ‘login’ program,this may be done as part of the login process, not requiring the user torun a separate program.) The ‘kinit’ command sends your request to the Kerberos masterserver machine. The server software looks for your principal name'sentry in the Kerberos database. If this entry exists, the Kerberos server creates and returns aticket-granting ticket and the key which allows you to use it, encryptedby your password. If ‘kinit’ can decrypt the Kerberos reply usingthe password you provide, it stores this ticket in a credentials cacheon your local machine for later use. The name of the credentials cachecan be specified in the ‘KRB5CCNAME’ environment variable. If thisvariable is not set, the name of the file will be/tmp/krb5cc_<uid>, where <uid> is your UNIX user-id, representedin decimal format. Now you use the ‘rlogin’ client to access the machine‘laughter’. host% rlogin laughter The ‘rlogin’ client checks your ticket file to see if you have aticket for the ‘host’ service for ‘laughter’. You don't, so‘rlogin’ uses the credential cache's ticket-granting ticket to makea request to the master server's ticket-granting service. This ticket-granting service receives the request for a ticket for‘host/laughter.mit.edu’, and looks in the masterdatabase for an entry for ‘host/laughter.mit.edu’.If the entry exists, the ticket-granting service issues you a ticket forthat service. That ticket is also cached in your credentials cache. The ‘rlogin’ client now sends that ticket to the ‘laughter’‘klogind’ service program. The service program checks the ticketby using its own service key. If the ticket is valid, it now knows youridentity. If you are allowed to login to ‘laughter’ (because yourusername matches one in /etc/passwd, or your Kerberos principal is inthe appropriate .k5login file), klogind will let youlogin. Definitions Following are definitions of some of the Kerberos terminology. client an entity that can obtain a ticket. This entity is usually either auser or a host. host a computer that can be accessed over a network. Kerberos in Greek mythology, the three-headed dog that guards the entrance to theunderworld. In the computing world, Kerberos is a network securitypackage that was developed at MIT. KDC Key Distribution Center. A machine that issues Kerberos tickets. keytab a key table file containing one or more keys. A host or serviceuses a keytab file in much the same way as a user uses his/herpassword. principal a string that names a specific entity to which a set of credentials maybe assigned. It can have an arbitrary number of components, butgenerally has three: primary the first part of a Kerberos principal. In the case of a user, itis the username. In the case of a service, it is the name of theservice. instance the second part of a Kerberos principal. It gives information thatqualifies the primary. The instance may be null. In the case of auser, the instance is often used to describe the intended use of thecorresponding credentials. In the case of a host, the instance is thefully qualified hostname. realm the logical network served by a single Kerberos database and a set ofKey Distribution Centers. By convention, realm names are generally alluppercase letters, to differentiate the realm from the internet domain. The typical format of a typical Kerberos principal isprimary/instance@REALM. service any program or computer you access over a network. Examples of servicesinclude “host” (a host, e.g., when you use telnet andrsh), “ftp” (FTP), “krbtgt” (authentication;cf. ticket-granting ticket), and “pop” (email). ticket a temporary set of electronic credentials that verify the identity of aclient for a particular service. TGT Ticket-Granting Ticket. A special Kerberos ticket that permits theclient to obtain additional Kerberos tickets within the same Kerberosrealm. Configuration Files Supported Encryption Types Any tag in the configuration files which requires a list of encryption types can be set to some combination of the following strings. des-cbc-crc DES cbc mode with CRC-32 des-cbc-md4 DES cbc mode with RSA-MD4 des-cbc-md5 DES cbc mode with RSA-MD5 des3-cbc-sha1des3-hmac-sha1des3-cbc-sha1-kd triple DES cbc mode with HMAC/sha1 des-hmac-sha1 DES with HMAC/sha1 aes256-cts-hmac-sha1-96aes256-cts AES-256 CTS mode with 96-bit SHA-1 HMAC aes128-cts-hmac-sha1-96aes128-cts AES-128 CTS mode with 96-bit SHA-1 HMAC arcfour-hmacrc4-hmacarcfour-hmac-md5 RC4 with HMAC/MD5 arcfour-hmac-exprc4-hmac-exparcfour-hmac-md5-exp exportable RC4 with HMAC/MD5 While aes128-cts and aes256-cts are supported for all Kerberos operations, they are not supported by older versions of our GSSAPI implementation (krb5-1.3.1 and earlier). By default, AES is enabled in this release. Sites wishing to use AES encryption types on their KDCs need to be careful not to give GSSAPI services AES keys if the servers have not been updated. If older GSSAPI services are given AES keys, then services may fail when clients supporting AES for GSSAPI are used. Sites may wish to use AES for user keys and for the ticket granting ticket key, although doing so requires specifying what encryption types are used as each principal is created. If all GSSAPI-based services have been updated before or with the KDC, this is not an issue. Salts Your Kerberos key is derived from your password. To ensure that people who happen to pick the same password do not have the same key, Kerberos 5 incorporates more information into the key using something called a salt. The supported values for salts are as follows. normal default for Kerberos Version 5 v4 the only type used by Kerberos Version 4, no salt norealm same as the default, without using realm information onlyrealm uses only realm information as the salt afs3 AFS version 3, only used for compatibility with Kerberos 4 in AFS special only used in very special cases; not fully supported krb5.conf The krb5.conf file contains Kerberos configuration information, including the locations of KDCs and admin servers for the Kerberos realms of interest, defaults for the current realm and for Kerberos applications, and mappings of hostnames onto Kerberos realms. Normally, you should install your krb5.conf file in the directory /etc. You can override the default location by setting the environment variable ‘KRB5_CONFIG’. The krb5.conf file is set up in the style of a Windows INI file. Sections are headed by the section name, in square brackets. Each section may contain zero or more relations, of the form: foo = bar or fubar = { foo = bar baz = quux } Placing a `*' at the end of a line indicates that this is the final value for the tag. This means that neither the remainder of this configuration file nor any other configuration file will be checked for any other values for this tag. For example, if you have the following lines: foo = bar* foo = baz then the second value of foo (baz) would never be read. The krb5.conf file may contain any or all of the following sections: libdefaults Contains default values used by the Kerberos V5 library. login Contains default values used by the Kerberos V5 login program. appdefaults Contains default values that can be used by Kerberos V5 applications. realms Contains subsections keyed by Kerberos realm names. Each subsectiondescribes realm-specific information, including where to find theKerberos servers for that realm. domain_realm Contains relations which map domain names and subdomains onto Kerberosrealm names. This is used by programs to determine what realm a hostshould be in, given its fully qualified domain name. logging Contains relations which determine how Kerberos programs are to performlogging. capaths Contains the authentication paths used with direct (nonhierarchical)cross-realm authentication. Entries in this section are used by theclient to determine the intermediate realms which may be used incross-realm authentication. It is also used by the end-service whenchecking the transited field for trusted intermediate realms. [libdefaults] The libdefaults section may contain any of the following relations: default_keytab_name This relation specifies the default keytab name to be used byapplication servers such as telnetd and rlogind. The default is/etc/krb5.keytab. default_realm Identifies the default Kerberos realm for the client. Set its value toyour Kerberos realm. If this is not specified and the TXT recordlookup is enabled (see ), then that information will beused to determine the default realm. If this tag is not set in thisconfiguration file and there is no DNS information found, then an errorwill be returned. default_tgs_enctypes Identifies the supported list of session key encryption types thatshould be returned by the KDC. The list may be delimited with commasor whitespace. Kerberos supports many different encryption types, andsupport for more is planned in the future. (see for a list of the accepted values for this tag). The defaultvalue is aes256-cts-hmac-sha1-96 des3-cbc-sha1 arcfour-hmac-md5 des-cbc-crc des-cbc-md5 des-cbc-md4. default_tkt_enctypes Identifies the supported list of session key encryption types thatshould be requested by the client. The format is the same as fordefault_tgs_enctypes. The default value for this tag isaes256-cts-hmac-sha1-96 des3-cbc-sha1 arcfour-hmac-md5 des-cbc-crc des-cbc-md5 des-cbc-md4. permitted_enctypes Identifies all encryption types that are permitted for use in sessionkey encryption. The default value for this tag isaes256-cts-hmac-sha1-96 des3-cbc-sha1 arcfour-hmac-md5 des-cbc-crc des-cbc-md5 des-cbc-md4. clockskew Sets the maximum allowable amount of clockskew in seconds that thelibrary will tolerate before assuming that a Kerberos message isinvalid. The default value is 300 seconds, or five minutes. kdc_timesync If this is set to 1 (for true), then client machines will compute thedifference between their time and the time returned by the KDC in thetimestamps in the tickets and use this value to correct for aninaccurate system clock. This corrective factor is only used by theKerberos library. The default is 1. kdc_req_checksum_type ap_req_checksum_type safe_checksum_type An integer which specifies the type of checksum to use. Used forcompatability with DCE security servers which do not support thedefault RSA MD5 used by this version of Kerberos.The possible values and their meanings are as follows. 1 CRC32 2 RSA MD4 3 RSA MD4 DES 4 DES CBC 7 RSA MD5 8 RSA MD5 DES 9 NIST SHA 12 HMAC SHA1 DES3 -138 Microsoft MD5 HMAC checksum type ccache_type Use this parameter on systems which are DCE clients, to specify thetype of cache to be created by kinit, or when forwarded tickets arereceived. DCE and Kerberos can share the cache, but some versions ofDCE do not support the default cache as created by this version ofKerberos. Use a value of 1 on DCE 1.0.3a systems, and a value of 2 onDCE 1.1 systems. The default value is 4. krb4_srvtab Specifies the location of the Kerberos V4 srvtab file. Default is/etc/srvtab. krb4_config Specifies the location of hte Kerberos V4 configuration file. Defaultis /etc/krb.conf. krb4_realms Specifies the location of the Kerberos V4 domain/realm translationfile. Default is /etc/krb.realms. dns_lookup_kdc Indicate whether DNS SRV records should be used to locate the KDCs andother servers for a realm, if they are not listed in the information forthe realm. (Note that the ‘admin_server’ entry must be in thefile, because the DNS implementation for it is incomplete.)Enabling this option does open up a type of denial-of-service attack, ifsomeone spoofs the DNS records and redirects you to another server.However, it's no worse than a denial of service, because that fake KDCwill be unable to decode anything you send it (besides the initialticket request, which has no encrypted data), and anything the fake KDCsends will not be trusted without verification using some secret that itwon't know.If this option is not specified but ‘dns_fallback’ is, that valuewill be used instead. If neither option is specified, the behaviordepends on configure-time options; if none were given, the default is toenable this option. If the DNS support is not compiled in, this entryhas no effect. dns_lookup_realm Indicate whether DNS TXT records should be used to determine theKerberos realm of a host.Enabling this option may permit a redirection attack, where spoofed DNSreplies persuade a client to authenticate to the wrong realm, whentalking to the wrong host (either by spoofing yet more DNS records or byintercepting the net traffic). Depending on how the client softwaremanages hostnames, however, it could already be vulnerable to suchattacks. We are looking at possible ways to minimize or eliminate thisexposure. For now, we encourage more adventurous sites to try usingSecure DNS.If this option is not specified but ‘dns_fallback’ is, that valuewill be used instead. If neither option is specified, the behaviordepends on configure-time options; if none were given, the default is todisable this option. If the DNS support is not compiled in, this entryhas no effect. dns_fallback General flag controlling the use of DNS for Kerberos information. Ifboth of the preceding options are specified, this option has no effect. extra_addresses This allows a computer to use multiple local addresses, in order toallow Kerberos to work in a network that uses NATs. The addressesshould be in a comma-separated list. udp_preference_limit When sending a message to the KDC, the library will try using TCP beforeUDP if the size of the message is above udp_preference_list.If the message is smaller than udp_preference_list, then UDPwill be tried before TCP. Regardless of the size, both protocols willbe tried if the first attempt fails. verify_ap_req_nofail If this flag is set, then an attempt to get initial credentials willfail if the client machine does not have a keytab. The default for theflag is not set. renew_lifetime The value of this tag is the default renewable lifetime forinitial tickets. The default value for the tag is0. noaddresses Setting this flag causes the initial Kerberos ticket to be addressless.The default for the flag is set. forwardable If this flag is set, initial tickets by default will be forwardable.The default value for this flag is not set. proxiable If this flag is set, initial tickets by default will be proxiable.The default value for this flag is not set. [appdefaults] Each tag in the [appdefaults] section names a Kerberos V5 application or an option that is used by some Kerberos V5 application[s]. The value of the tag defines the default behaviors for that application. For example: [appdefaults] telnet = { ATHENA.MIT.EDU = { option1 = false } } telnet = { option1 = true option2 = true } ATHENA.MIT.EDU = { option2 = false } option2 = true The above four ways of specifying the value of an option are shown in order of decreasing precedence. In this example, if telnet is running in the realm EXAMPLE.COM, it should, by default, have option1 and option2 set to true. However, a telnet program in the realm ATHENA.MIT.EDU should have option1 set to false and option2 set to true. Any other programs in ATHENA.MIT.EDU should have option2 set to false by default. Any programs running in other realms should have option2 set to true. The list of specifiable options for each application may be found in that application's man pages. The application defaults specified here are overridden by those specified in the [realms] section. A special application name (afs_krb5) is used by the krb524 service to know whether new format AFS tokens based on Kerberos 5 can be used rather than the older format which used a converted Kerberos 4 ticket. The new format allows for cross-realm authentication without introducing a security hole. It is used by default. Older AFS servers (before OpenAFS 1.2.8) will not support the new format. If servers in your cell do not support the new format, you will need to add an afs_krb5 relation to the appdefaults section. The following config file shows how to disable new format AFS tickets for the afs.example.com cell in the EXAMPLE.COM realm. [appdefaults] afs_krb5 = { EXAMPLE.COM = { afs/afs.example.com = false } } [login] Each tag in the [login] section of the file is an option for login.krb5. This section may contain any of the following relations: krb5_get_tickets Indicate whether or not to use a user's password to get V5 tickets.The default value is true. krb4_get_tickets Indicate whether or not to user a user's password to get V4 tickets.The default value is false. krb4_convert Indicate whether or not to use the Kerberos conversion daemon to get V4tickets. The default value is false. If this isset to false and krb4_get_tickets is true, then login will get the V5tickets directly using the Kerberos V4 protocol directly. This doesnot currently work with non-MIT-V4 salt types (such as the AFS3 salttype). Note that if this is set to true and krb524d is not running,login will hang for approximately a minute under Solaris, due to aSolaris socket emulation bug. krb_run_aklog Indicate whether or not to run aklog. The default value isfalse. aklog_path Indicate where to find aklog. The default value is$(prefix)/bin/aklog. accept_passwd A true value will cause login not to accept plaintext passwords. Thedefault value is false. This is not yetimplemented. [realms] Each tag in the [realms] section of the file is the name of a Kerberos realm. The value of the tag is a subsection with relations that define the properties of that particular realm. For each realm, the following tags may be specified in the realm's subsection: kdc The name of a host running a KDC for that realm. An optional portnumber (separated from the hostname by a colon) may be included. Foryour computer to be able to communicate with the KDC for each realm,this tag must be given a value in each realm subsection in theconfiguration file, or there must be DNS SRV records specifying theKDCs (see ). master_kdc Identifies the master KDC(s). Currently, this tag is used in only onecase: If an attempt to get credentials fails because of an invalidpassword, the client software will attempt to contact the master KDC,in case the user's password has just been changed, and the updateddatabase has not been propagated to the slave servers yet. (We don'tcurrently check whether the KDC from which the initial response cameis on the master KDC list. That may be fixed in the future.) database_module This relation indicates the name of the configuration section under [dbmodules] for database specific parameters used by the loadable database library. admin_server Identifies the host where the administration server is running.Typically, this is the master Kerberos server. This tag must be givena value in order to communicate with the kadmin server for the realm. default_domain This tag is used for Kerberos 4 compatibility. Kerberos 4 does notrequire the entire hostname of a server to be in its principal likeKerberos 5 does. This tag provides the domain name needed to produce afull hostname when translating V4 principal names into V5 principalnames. All servers in this realm are assumed to be in the domain givenas the value of this tag v4_instance_convert This subsection allows the administrator to configure exceptions to thedefault_domain mapping rule. It contains V4 instances (the tag name)which should be translated to some specific hostname (the tag value) asthe second component in a Kerberos V5 principal name. v4_realm This relation is used by the krb524 library routines when converting aV5 principal name to a V4 principal name. It is used when the V4 realmname and the V5 realm name are not the same, but still share the sameprincipal names and passwords. The tag value is the Kerberos V4 realmname. auth_to_local_names This subsection allows you to set explicit mappings from principalnames to local user names. The tag is the mapping name, and the valueis the corresponding local user name. auth_to_local This tag allows you to set a general rule for mapping principal namesto local user names. It will be used if there is not an explicitmapping for the principal name that is being translated. The possiblevalues are: DB:filename The principal will be looked up in the database filename. Supportfor this is not currently compiled in by default. RULE:exp The local name will be formulated from exp.The format for exp is[n:$d..string](regexp)s/pattern/replacement/g.The integer n indicates how many components the target principalshould have. If this matches, then a string will be formed by puttingtogether the components of the principal in the order indicated by eachinteger d, and the arbitrary string string (i.e. if theprincipal was johndoe/admin then [2:$2$1foo] would result inthe string "adminjohndoefoo". If this string matchesregexp, then the s//[g] substitution command will be run over thestring. The optional g will cause the substitution to be global overthe string, instead of replacing only the first match in the string. DEFAULT The principal name will be used as the local user name. If theprincipal has more than one component or is not in the default realm,this rule is not applicable and the conversion will fail. For example: [realms] ATHENA.MIT.EDU = { auth_to_local = { RULE:[2:$1](johndoe)s/^.*$/guest/ RULE:[2:$1;$2](^.*;admin$)s/;admin$// RULE:[2:$2](^.*;root)s/^.*$/root/ DEFAULT } } would result in any principal without root or admin asthe second component to be translated with the default rule. Aprincipal with a second component of admin will become its firstcomponent. root will be used as the local name for anyprincipal with a second component of root. The exception tothese two rules are any principals johndoe/*, which willalways get the local name guest. [domain_realm] The [domain_realm] section provides a translation from a domain name or hostname to a Kerberos realm name. The tag name can be a host name, or a domain name, where domain names are indicated by a prefix of a period (‘.’). The value of the relation is the Kerberos realm name for that particular host or domain. Host names and domain names should be in lower case. If no translation entry applies, the host's realm is considered to be the hostname's domain portion converted to upper case. For example, the following [domain_realm] section: [domain_realm] .mit.edu = ATHENA.MIT.EDU mit.edu = ATHENA.MIT.EDU crash.mit.edu = TEST.ATHENA.MIT.EDU example.com = EXAMPLE.COM maps crash.mit.edu into the TEST.ATHENA.MIT.EDU realm. All other hosts in the mit.edu domain will map by default to the ATHENA.MIT.EDU realm, and all hosts in the example.com domain will map by default into the EXAMPLE.COM realm. Note the entries for the hosts mit.edu and example.com. Without these entries, these hosts would be mapped into the Kerberos realms ‘EDU’ and ‘ORG’, respectively. [logging]The [logging] section indicates how a particular entity is to perform its logging. The relations in this section assign one or more values to the entity name. Currently, the following entities are used: kdc These entries specify how the KDC is to perform its logging. admin_server These entries specify how the administrative serveris to perform its logging. default These entries specify how to perform logging in theabsence of explicit specifications otherwise. Values are of the following forms: FILE=<filename> FILE:<filename> This value causes the entity's logging messages to go to the specifiedfile. If the ‘=’ form is used, the file is overwritten. If the‘:’ form is used, the file is appended to. STDERR This value causes the entity's logging messages to go to its standarderror stream. CONSOLE This value causes the entity's logging messages to go to the console, ifthe system supports it. DEVICE=<devicename> This causes the entity's logging messages to go to the specified device. SYSLOG[:<severity>[:<facility>]] This causes the entity's logging messages to go to the system log.The severity argument specifies the default severity of system logmessages. This may be any of the following severities supported by thesyslog(3) call, minus the LOG_ prefix: LOG_EMERG, LOG_ALERT,LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, and LOG_DEBUG.For example, a value of ‘CRIT’ would specify LOG_CRIT severity.The facility argument specifies the facility under which the messagesare logged. This may be any of the following facilities supported bythe syslog(3) call minus the LOG_ prefix: LOG_KERN, LOG_USER, LOG_MAIL,LOG_DAEMON, LOG_AUTH, LOG_LPR, LOG_NEWS, LOG_UUCP, LOG_CRON, andLOG_LOCAL0 through LOG_LOCAL7.If no severity is specified, the default is ERR. If no facility isspecified, the default is AUTH. In the following example, the logging messages from the KDC will go to the console and to the system log under the facility LOG_DAEMON with default severity of LOG_INFO; and the logging messages from the administrative server will be appended to the file /var/adm/kadmin.log and sent to the device /dev/tty04. [logging] kdc = CONSOLE kdc = SYSLOG:INFO:DAEMON admin_server = FILE:/var/adm/kadmin.log admin_server = DEVICE=/dev/tty04 [capaths] In order to perform direct (non-hierarchical) cross-realm authentication, a database is needed to construct the authentication paths between the realms. This section defines that database. A client will use this section to find the authentication path between its realm and the realm of the server. The server will use this section to verify the authentication path used by the client, by checking the transited field of the received ticket. There is a tag for each participating realm, and each tag has subtags for each of the realms. The value of the subtags is an intermediate realm which may participate in the cross-realm authentication. The subtags may be repeated if there is more then one intermediate realm. A value of "." means that the two realms share keys directly, and no intermediate realms should be allowed to participate. There are n**2 possible entries in this table, but only those entries which will be needed on the client or the server need to be present. The client needs a tag for its local realm, with subtags for all the realms of servers it will need to authenticate with. A server needs a tag for each realm of the clients it will serve. For example, ANL.GOV, PNL.GOV, and NERSC.GOV all wish to use the ES.NET realm as an intermediate realm. ANL has a sub realm of TEST.ANL.GOV which will authenticate with NERSC.GOV but not PNL.GOV. The [capaths] section for ANL.GOV systems would look like this: [capaths] ANL.GOV = { TEST.ANL.GOV = . PNL.GOV = ES.NET NERSC.GOV = ES.NET ES.NET = . } TEST.ANL.GOV = { ANL.GOV = . } PNL.GOV = { ANL.GOV = ES.NET } NERSC.GOV = { ANL.GOV = ES.NET } ES.NET = { ANL.GOV = . } The [capaths] section of the configuration file used on NERSC.GOV systems would look like this: [capaths] NERSC.GOV = { ANL.GOV = ES.NET TEST.ANL.GOV = ES.NET TEST.ANL.GOV = ANL.GOV PNL.GOV = ES.NET ES.NET = . } ANL.GOV = { NERSC.GOV = ES.NET } PNL.GOV = { NERSC.GOV = ES.NET } ES.NET = { NERSC.GOV = . } TEST.ANL.GOV = { NERSC.GOV = ANL.GOV NERSC.GOV = ES.NET } In the above examples, the ordering is not important, except when the same subtag name is used more then once. The client will use this to determine the path. (It is not important to the server, since the transited field is not sorted.) This feature is not currently supported by DCE. DCE security servers can be used with Kerberized clients and servers, but versions prior to DCE 1.1 did not fill in the transited field, and should be used with caution. [dbdefaults] The [dbdefaults] section provides default values for the database specific parameters. It can also specify the configuration section under [dbmodules] section for database specific parameters used by the database library.(see ). The following tags are used in this section: database_module This relation indicates the name of the configuration section under the [dbmodules] for database specific parameters used by the loadable database library. ldap_kerberos_container_dn This LDAP specific tag indicates the DN of the container object where the realm objects will be located. This value is used if the container object is not mentioned in the configuration section under [dbmodules]. ldap_kdc_dn This LDAP specific tag indicates the default bind DN for the KDC server. The KDC server does a login to the directory as this object. This object should have the rights to read the Kerberos data in the LDAP database. This value is used if the bind DN for the KDC is not mentioned in the configuration section under [dbmodules]. ldap_kadmind_dn This LDAP specific tag indicates the default bind DN for the Administration server. The administration server does a login to the directory as this object. This object should have the rights to read and write the Kerberos data in the LDAP database. This value is used if the bind DN for the Administration server is not mentioned in the configuration section under [dbmodules]. ldap_service_password_file This LDAP specific tag indicates the file containing the stashed passwords for the objects used by the Kerberos servers to bind to the LDAP server. This file must be kept secure. This value is used if no service password file is mentioned in the configuration section under [dbmodules]. ldap_server This LDAP specific tag indicates the list of LDAP servers that the Kerberos servers can connect to. The list of LDAP servers is whitespace-separated. The LDAP server is specified by a LDAP URI. This value is used if no LDAP servers are mentioned in the configuration section under [dbmodules]. It is recommended to use the ldapi:// or ldaps:// interface and not to use ldap:// interface. ldap_conns_per_server This LDAP specific tag indicates the number of connections to be maintained per LDAP server. This value is used if the number of connections per LDAP server are not mentioned in the configuration section under [dbmodules]. The default value is 5. [dbmodules] Contains database specific parameters used by the database library. Each tag in the [dbmodules] section of the file names a configuration section for database specific parameters that can be referred to by a realm. The value of the tag is a subsection where the relations in that subsection define the database specific parameters. For each section, the following tags may be specified in the subsection: db_library This tag indicates the name of the loadable database library. The value should be ‘db2’ for DB2 database and ‘kldap’ for LDAP database. ldap_kerberos_container_dn This LDAP specific tag indicates the DN of the container object where the realm objects will be located. ldap_kdc_dn This LDAP specific tag indicates the default bind DN for the KDC server. The KDC server does a login to the directory as this object. This object should have the rights to read the Kerberos data in the LDAP database. ldap_kadmind_dn This LDAP specific tag indicates the default bind DN for the Administration server. The administration server does a login to the directory as this object. This object should have the rights to read and write the Kerberos data in the LDAP database. ldap_service_password_file This LDAP specific tag indicates the file containing the stashed passwords for the objects used by the Kerberos servers to bind to the LDAP server. This file must be kept secure. ldap_server This LDAP specific tag indicates the list of LDAP servers that the Kerberos servers can connect to. The list of LDAP servers is whitespace-separated. The LDAP server is specified by a LDAP URI. It is recommended to use ldapi:// or ldaps:// interface to connect to the LDAP server. ldap_conns_per_server This LDAP specific tags indicates the number of connections to be maintained per LDAP server. Sample krb5.conf File Here is an example of a generic krb5.conf file: [libdefaults] default_realm = ATHENA.MIT.EDU default_tkt_enctypes = des3-hmac-sha1 des-cbc-crc default_tgs_enctypes = des3-hmac-sha1 des-cbc-crc dns_lookup_kdc = true dns_lookup_realm = false [realms] ATHENA.MIT.EDU = { kdc = kerberos.mit.edu kdc = kerberos-1.mit.edu kdc = kerberos-2.mit.edu:750 admin_server = kerberos.mit.edu master_kdc = kerberos.mit.edu default_domain = mit.edu } EXAMPLE.COM = { kdc = kerberos.example.com kdc = kerberos-1.example.com admin_server = kerberos.example.com } OPENLDAP.MIT.EDU = { kdc = kerberos.mit.edu admin_server = kerberos.mit.edu database_module = openldap_ldapconf } [domain_realm] .mit.edu = ATHENA.MIT.EDU mit.edu = ATHENA.MIT.EDU [capaths] ATHENA.MIT.EDU = { EXAMPLE.COM = . } EXAMPLE.COM = { ATHENA.MIT.EDU = . } [logging] kdc = SYSLOG:INFO admin_server = FILE=/var/kadm5.log [dbdefaults] ldap_kerberos_container_dn = cn=krbcontainer,o=mit [dbmodules] openldap_ldapconf = { db_library = kldap ldap_kerberos_container_dn = cn=krbcontainer,o=mit ldap_kdc_dn = "cn=krbadmin,o=mit" # this object needs to have read rights on # the realm container, principal container and realm sub-trees ldap_kadmind_dn = "cn=krbadmin,o=mit" # this object needs to have read and write rights on # the realm container, principal container and realm sub-trees ldap_service_password_file = /etc/kerberos/service.keyfile ldap_servers = ldaps://kerberos.mit.edu ldap_conns_per_server = 5 } kdc.conf The kdc.conf file contains KDC configuration information, including defaults used when issuing Kerberos tickets. Normally, you should install your kdc.conf file in the directory /usr/local/var/krb5kdc. You can override the default location by setting the environment variable ‘KRB5_KDC_PROFILE’. The kdc.conf file is set up in the same format as the krb5.conf file. (See .) The kdc.conf file may contain any or all of the following three sections: kdcdefaults Contains default values for overall behavior of the KDC. realms Contains subsections keyed by Kerberos realm names. Each subsectiondescribes realm-specific information, including where to find theKerberos servers for that realm. logging Contains relations which determine how Kerberos programs are to performlogging. [kdcdefaults] The following relation is defined in the [kdcdefaults] section: kdc_ports This relation lists the ports on which the Kerberos server shouldlisten for UDP requests by default. This list is a comma separatedlist of integers.If this relation is not specified, the compiled-in default is88,750, the first being the assigned Kerberos portand the second which was used by Kerberos V4. kdc_tcp_ports This relation lists the ports on which the Kerberos server shouldlisten for TCP connections by default. This list is a comma separatedlist of integers.If this relation is not specified, the compiled-in default is not tolisten for TCP connections at all.If you wish to change this (which we do not recommend, because thecurrent implementation has little protection against denial-of-serviceattacks), the standard port number assigned for Kerberos TCP trafficis port 88. v4_mode This string specifies how the KDC should respond to Kerberos 4packets. The possible values are none, disable, full, and nopreauth.The default value is none. [realms] Each tag in the [realms] section of the file names a Kerberos realm. The value of the tag is a subsection where the relations in that subsection define KDC parameters for that particular realm. For each realm, the following tags may be specified in the [realms] subsection: acl_file (String.) Location of the access control list (acl) file that kadminuses to determine which principals are allowed which permissions on thedatabase. The default is /usr/local/var/krb5kdc/kadm5.acl. admin_keytab (String.) Location of the keytab file that the legacy administrationdaemons kadmind4 and v5passwdd use to authenticate tothe database. The default is /usr/local/var/krb5kdc/kadm5.keytab. database_name (String.) Location of the Kerberos database for this realm. Thedefault is /usr/local/var/krb5kdc/principal. default_principal_expiration (Absolute time string.) Specifies the default expiration date ofprincipals created in this realm. The default value for this tag is0. default_principal_flags (Flag string.) Specifies the default attributes of principals createdin this realm. The format for this string is a comma-separated list offlags, with '+' before each flag that should be enabled and '-' beforeeach flag that should be disabled. The default ispostdateable, forwardable, tgt-based, renewable, proxiable, dup-skey, allow-tickets, and service enabled..There are a number of possible flags: postdateable Enabling this flag allows the principal to obtain postdateable tickets. forwardable Enabling this flag allows the principal to obtain forwardable tickets. tgt-based Enabling this flag allows a principal to obtain tickets based on aticket-granting-ticket, rather than repeating the authenticationprocess that was used to obtain the TGT. renewable Enabling this flag allows the principal to obtain renewable tickets. proxiable Enabling this flag allows the principal to obtain proxy tickets. dup-skey Enabling this flag allows the principal to obtain a session key foranother user, permitting user-to-user authentication for this principal. allow-tickets Enabling this flag means that the KDC will issue tickets for thisprincipal. Disabling this flag essentially deactivates the principalwithin this realm. preauth If this flag is enabled on a client principal, then that principal isrequired to preauthenticate to the KDC before receiving any tickets.On a service principal, enabling this flag means that service ticketsfor this principal will only be issued to clients with a TGT that hasthe preauthenticated ticket set. hwauth If this flag is enabled, then the principal is required topreauthenticate using a hardware device before receiving any tickets. pwchange Enabling this flag forces a password change for this principal. service Enabling this flag allows the the KDC to issue service tickets for thisprincipal. pwservice If this flag is enabled, it marks this principal as a password changeservice. This should only be used in special cases, for example, if auser's password has expired, then the user has to get tickets for thatprincipal without going through the normal password authentication inorder to be able to change the password. dict_file (String.) Location of the dictionary file containing strings that arenot allowed as passwords. If none is specified or if there is nopolicy assigned to the principal, no dictionary checks of passwordswill be performed. kadmind_port (Port number.) Specifies the port on which the kadmind daemon is tolisten for this realm. The assigned port for kadmind is749. kpasswd_port (Port number.) Specifies the port on which the kpasswd daemon is tolisten for this realm. The default is 464. key_stash_file (String.) Specifies the location where the master key has been stored(via kdb5_util stash). The default is/usr/local/var/krb5kdc/.k5.REALM, where REALM is theKerberos realm. kdc_ports (String.) Specifies the list of ports that the KDC is to listen tofor UDP requests for this realm. By default, the value of kdc_portsas specified in the [kdcdefaults] section is used. kdc_tcp_ports (String.) Specifies the list of ports that the KDC is to listen tofor TCP requests for this realm. By default, the value ofkdc_tcp_ports as specified in the [kdcdefaults] section is used. master_key_name (String.) Specifies the name of the principal associated with themaster key. The default is K/M. master_key_type (Key type string.) Specifies the master key's key type. The defaultvalue for this is des3-cbc-sha1. For a list of allpossible values, see . max_life (Delta time string.) Specifes the maximum time period for which aticket may be valid in this realm. The default value is10 hours. max_renewable_life (Delta time string.) Specifies the maximum time period during which avalid ticket may be renewed in this realm. The default value is0. supported_enctypes List of key:salt strings. Specifies the default key/salt combinations ofprincipals for this realm. Any principals created through kadminwill have keys of these types. The default value for this tag isdes3-hmac-sha1:normal des-cbc-crc:normal. For lists of possible values, see and . reject_bad_transit A boolean value (true, false). If set to true, theKDC will check the list of transited realms for cross-realm ticketsagainst the transit path computed from the realm names and thecapaths section of its krb5.conf file; if the path in theticket to be issued contains any realms not in the computed path, theticket will not be issued, and an error will be returned to the clientinstead. If this value is set to false, such tickets will beissued anyways, and it will be left up to the application server tovalidate the realm transit path.If the disable-transited-check flag is set in the incomingrequest, this check is not performed at all. Having thereject_bad_transit option will cause such ticket requests to berejected always.This transit path checking and config file option currently apply onlyto TGS requests.Earlier versions of the MIT release (before 1.2.3) had bugs in theapplication server support such that the server-side checks may not beperformed correctly. We recommend turning this option on, unless youknow that all application servers in this realm have been updated tofixed versions of the software, and for whatever reason, you don't wantthe KDC to do the validation.This is a per-realm option so that multiple-realm KDCs may control itseparately for each realm, in case (for example) one realm has had thesoftware on its application servers updated but another has not.This option defaults to true. Sample kdc.conf File Here's an example of a kdc.conf file: [kdcdefaults] kdc_ports = 88 [realms] ATHENA.MIT.EDU = { kadmind_port = 749 max_life = 12h 0m 0s max_renewable_life = 7d 0h 0m 0s master_key_type = des3-hmac-sha1 supported_enctypes = des3-hmac-sha1:normal des-cbc-crc:normal des-cbc-crc:v4 } [logging] kdc = FILE:/usr/local/var/krb5kdc/kdc.log admin_server = FILE:/usr/local/var/krb5kdc/kadmin.log Using DNS Mapping Hostnames onto Kerberos Realms Mapping hostnames onto Kerberos realms is done in one of two ways. The first mechanism, which has been in use for years in MIT-based Kerberos distributions, works through a set of rules in the krb5.conf configuration file. (See .) You can specify mappings for an entire domain or subdomain, and/or on a hostname-by-hostname basis. Since greater specificity takes precedence, you would do this by specifying the mappings for a given domain or subdomain and listing the exceptions. The second mechanism works by looking up the information in special TXT records in the Domain Name Service. This is currently not used by default because security holes could result if the DNS TXT records were spoofed. If this mechanism is enabled on the client, it will try to look up a TXT record for the DNS name formed by putting the prefix _kerberos in front of the hostname in question. If that record is not found, it will try using _kerberos and the host's domain name, then its parent domain, and so forth. So for the hostname BOSTON.ENGINEERING.FOOBAR.COM, the names looked up would be: _kerberos.boston.engineering.foobar.com _kerberos.engineering.foobar.com _kerberos.foobar.com _kerberos.com The value of the first TXT record found is taken as the realm name. (Obviously, this doesn't work all that well if a host and a subdomain have the same name, and different realms. For example, if all the hosts in the ENGINEERING.FOOBAR.COM domain are in the ENGINEERING.FOOBAR.COM realm, but a host named ENGINEERING.FOOBAR.COM is for some reason in another realm. In that case, you would set up TXT records for all hosts, rather than relying on the fallback to the domain name.) Even if you do not choose to use this mechanism within your site, you may wish to set it up anyway, for use when interacting with other sites. Hostnames for KDCs MIT recommends that your KDCs have a predefined set of CNAME records (DNS hostname aliases), such as kerberos for the master KDC and kerberos-1, kerberos-2, … for the slave KDCs. This way, if you need to swap a machine, you only need to change a DNS entry, rather than having to change hostnames. A new mechanism for locating KDCs of a realm through DNS has been added to the MIT Kerberos V5 distribution. A relatively new record type called SRV has been added to DNS. Looked up by a service name and a domain name, these records indicate the hostname and port number to contact for that service, optionally with weighting and prioritization. (See RFC 2782 if you want more information. You can follow the example below for straightforward cases.) The use with Kerberos is fairly straightforward. The domain name used in the SRV record name is the domain-style Kerberos realm name. (It is possible to have Kerberos realm names that are not DNS-style names, but we don't recommend it for Internet use, and our code does not support it well.) Several different Kerberos-related service names are used: _kerberos._udp This is for contacting any KDC by UDP. This entry will be used the mostoften. Normally you should list port 88 on each of your KDCs. _kerberos._tcp This is for contacting any KDC by TCP. The MIT KDC by default will notlisten on any TCP ports, so unless you've changed the configuration oryou're running another KDC implementation, you should leave thisunspecified. If you do enable TCP support, normally you should useport 88. _kerberos-master._udp This entry should refer to those KDCs, if any, that will immediately seepassword changes to the Kerberos database. This entry is used only inone case, when the user is logging in and the password appears to beincorrect; the master KDC is then contacted, and the same password usedto try to decrypt the response, in case the user's password had recentlybeen changed and the first KDC contacted hadn't been updated. Only ifthat fails is an “incorrect password” error given.If you have only one KDC, or for whatever reason there is no accessibleKDC that would get database changes faster than the others, you do notneed to define this entry. _kerberos-adm._tcp This should list port 749 on your master KDC.Support for it is not complete at this time, but it will eventually beused by the kadmin program and related utilities. For now, youwill also need the admin_server entry in krb5.conf.(See .) _kpasswd._udp This should list port 464 on your master KDC.It is used when a user changes her password. _kerberos-iv._udp This should refer to your KDCs that serve Kerberos version 4 requests,if you have Kerberos v4 enabled. Be aware, however, that the DNS SRV specification requires that the hostnames listed be the canonical names, not aliases. So, for example, you might include the following records in your (BIND-style) zone file: $ORIGIN foobar.com. _kerberos TXT "FOOBAR.COM" kerberos CNAME daisy kerberos-1 CNAME use-the-force-luke kerberos-2 CNAME bunny-rabbit _kerberos._udp SRV 0 0 88 daisy SRV 0 0 88 use-the-force-luke SRV 0 0 88 bunny-rabbit _kerberos-master._udp SRV 0 0 88 daisy _kerberos-adm._tcp SRV 0 0 749 daisy _kpasswd._udp SRV 0 0 464 daisy As with the DNS-based mechanism for determining the Kerberos realm of a host, we recommend distributing the information this way for use by other sites that may want to interact with yours using Kerberos, even if you don't immediately make use of it within your own site. If you anticipate installing a very large number of machines on which it will be hard to update the Kerberos configuration files, you may wish to do all of your Kerberos service lookups via DNS and not put the information (except for admin_server as noted above) in future versions of your krb5.conf files at all. Eventually, we hope to phase out the listing of server hostnames in the client-side configuration files; making preparations now will make the transition easier in the future. Administrating the Kerberos Database Your Kerberos database contains all of your realm's Kerberos principals, their passwords, and other administrative information about each principal. For the most part, you will use the kdb5_util program to manipulate the Kerberos database as a whole, and the kadmin program to make changes to the entries in the database. (One notable exception is that users will use the kpasswd program to change their own passwords.) The kadmin program has its own command-line interface, to which you type the database administrating commands. Kdb5_util provides a means to create, delete, load, or dump a Kerberos database. It also includes a command to stash a copy of the master database key in a file on a KDC, so that the KDC can authenticate itself to the kadmind and krb5kdc daemons at boot time. Kadmin provides for the maintenance of Kerberos principals, KADM5 policies, and service key tables (keytabs). It exists as both a Kerberos client, kadmin, using Kerberos authentication and an RPC, to operate securely from anywhere on the network, and as a local client, kadmin.local, intended to run directly on the KDC without Kerberos authentication. kadmin.local need not run on the kdc if the database is LDAP. Other than the fact that the remote client uses Kerberos to authenticate the person using it, the functionalities of the two versions are identical. The local version is necessary to enable you to set up enough of the database to be able to use the remote version. It replaces the now obsolete kdb5_edit (except for database dump and load, which are provided by kdb5_util). The remote version authenticates to the KADM5 server using the service principal kadmin/admin. If the credentials cache contains a ticket for the kadmin/admin principal, and the ‘-c ccache’ option is specified, that ticket is used to authenticate to KADM5. Otherwise, the ‘-p’ and ‘-k’ options are used to specify the client Kerberos principal name used to authenticate. Once kadmin has determined the principal name, it requests a kadmin/admin Kerberos service ticket from the KDC, and uses that service ticket to authenticate to KADM5. Kadmin Options You can invoke kadmin or kadmin.local with any of the following options: -r REALM Use REALM as the default Kerberos realm for the database. -p principal Use the Kerberos principal principal to authenticate to Kerberos.If this option is not given, kadmin will append admin toeither the primary principal name, the environment variable USER, or tothe username obtained from getpwuid, in order of preference. -q query Pass query directly to kadmin. This is useful for writingscripts that pass specific queries to kadmin.You can invoke kadmin with any of the following options: -k [-t keytab] Use the keytab keytab to decrypt the KDC response instead ofprompting for a password on the TTY. In this case, the principal willbe ‘host/hostname’. If -t is not used to specify a keytab,then the default keytab will be used. -c credentials cache Use credentials_cache as the credentials cache. The credentialscache should contain a service ticket for the kadmin/adminservice, which can be acquired with the kinit program. If thisoption is not specified, kadmin requests a new service ticketfrom the KDC, and stores it in its own temporary ccache. -w password Use password as the password instead of prompting for one on theTTY. Note: placing the password for a Kerberos principal withadministration access into a shell script can be dangerous ifunauthorized users gain read access to the script. -x db_args Specifies the database specific arguments. -x host=<hostname> Specifies the LDAP server to connect to by a LDAP URI. It is recommend to useldapi:// or ldaps:// interface to connect to the LDAP server. -x binddn=<bind_dn> Specifies the Distinguished Name (DN) of the object used by the administration server to bind to the LDAP server. This object should have the read and write rights on the realm container, principal container and realm subtree. -x bindpwd=<bind_password> Specifies the password for the above mentioned binddn. It is recommended not touse this option. Instead, the password can be stashed using thestashsrvpw command of kdb5_ldap_util.Note: This database specific argument is applicable only to kadmin.localand the KADM5 server. -s admin_server[:port] Specifies the admin server that kadmin should contact.You can invoke kadmin.local with an of the follwing options: -d_ dbname Specifies the name of the Kerberos database. -e "enctypes ..." Sets the list of cryptosystem and salt types to be used for any newkeys created. See and foravailable types. -m Do not authenticate using a keytab. This option will cause kadmin toprompt for the master database password. Date Format Many of the kadmin commands take a duration or time as an argument. The date can appear in a wide variety of formats, such as: "15 minutes" "7 days" "1 month" "2 hours" "400000 seconds" "next year" "this Monday" "next Monday" yesterday tomorrow now "second Monday" fortnight "3/31/1992 10:00:07 PST" "January 23, 2007 10:05pm" "22:00 GMT" Note that if the date specification contains spaces, you must enclose it in double quotes. Note also that you cannot use a number without a unit. (I.e., “"60 seconds"” is correct, but “60” is incorrect.) All keywords are case-insensitive. The following is a list of all of the allowable keywords. Months january, jan, february, feb, march, mar, april, apr, may, june, jun,july, jul, august, aug, september, sep, sept, october, oct, november,nov, december, dec Days sunday, sun, monday, mon, tuesday, tues, tue, wednesday, wednes, wed,thursday, thurs, thur, thu, friday, fri, saturday, sat Units year, month, fortnight, week, day, hour, minute, min, second, sec Relative tomorrow, yesterday, today, now, last, this, next, first, second,third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh,twelfth, ago Time Zones kadmin recognizes abbreviations for most of the world's timezones. A complete listing appears in . 12-hour Time Delimiters am, pm Principals Each entry in the Kerberos database contains a Kerberos principal (see ) and the attributes and policies associated with that principal. Retrieving Information About a Principal Attributes To retrieve a listing of the attributes and/or policies associated with a principal, use the kadmin get_principal command, which requires the “inquire” administrative privilege. The syntax is: get_principal principal The get_principal command has the alias getprinc. For example, suppose you wanted to view the attributes of the principal jennifer/root@ATHENA.MIT.EDU. You would type: shell% kadmin kadmin: getprinc jennifer/root Principal: jennifer/root@ATHENA.MIT.EDU Expiration date: [never] Last password change: Mon Jan 31 02:06:40 EDT 2002 Password Expiration date: [none] Maximum ticket life: 0 days 10:00:00 Maximum renewable life: 7 days 00:00:00 Last modified: Wed Jul 24 14:46:25 EDT 2002 (joeadmin/admin@ATHENA.MIT.EDU) Last successful authentication: Mon Jul 29 18:20:17 EDT 2002 Last failed authentication: Mon Jul 29 18:18:54 EDT 2002 Failed password attempts: 3 Number of keys: 2 Key: vno 2, Triple DES cbc mode with HMAC/sha1, no salt Key: vno 2, DES cbc mode with CRC-32, no salt Attributes: DISALLOW_FORWARDABLE, DISALLOW_PROXIABLE Policy: [none] kadmin: The get_principal command has a -terse option, which lists the fields as a quoted, tab-separated string. For example: kadmin: getprinc -terse jennifer/root jennifer/root@ATHENA.MIT.EDU 0 1027458564 0 36000 (joeadmin/admin@ATHENA.MIT.EDU 1027536385 18 2 0 [none] 604800 1027980137 1027980054 3 2 1 2 16 0 1 2 1 0 kadmin: Retrieving a List of Principals To generate a listing of principals, use the kadmin list_principals command, which requires the “list” privilege. The syntax is: list_principals [ expression ] where expression is a shell-style glob expression that can contain the characters ‘*’, ‘?’, ‘[’, and ‘]’. All policy names matching the expression are displayed. The list_principals command has the aliases listprincs, get_principals, and getprincs. For example: kadmin: listprincs test* test3@ATHENA.MIT.EDU test2@ATHENA.MIT.EDU test1@ATHENA.MIT.EDU testuser@ATHENA.MIT.EDU kadmin: If no expression is provided, all principals are printed. Privileges Administrative privileges for the Kerberos database are stored in the file kadm5.acl. The format of the file is: Kerberos_principal permissions [target_principal] [restrictions] The Kerberos principal (and optional target principal) can include the “*” wildcard, so if you want any principal with the instance “admin” to have full permissions on the database, you could use the principal “*/admin@REALM” where “REALM” is your Kerberos realm. target_principal can also include backreferences to Kerberos_principal, in which "*number" matches the component number in the Kerberos_principal. Note: a common use of an admin instance is so you can grant separate permissions (such as administrator access to the Kerberos database) to a separate Kerberos principal. For example, the user joeadmin might have a principal for his administrative use, called joeadmin/admin. This way, joeadmin would obtain joeadmin/admin tickets only when he actually needs to use those permissions. The permissions are represented by single letters; UPPER-CASE letters represent negative permissions. The permissions are: a allows the addition of principals or policies in the database. A disallows the addition of principals or policies in the database. d allows the deletion of principals or policies in the database. D disallows the deletion of principals or policies in the database. m allows the modification of principals or policies in the database. M disallows the modification of principals or policies in the database. c allows the changing of passwords for principals in the database. C disallows the changing of passwords for principals in the database. i allows inquiries to the database. I disallows inquiries to the database. l allows the listing of principals or policies in the database. L disallows the listing of principals or policies in the database. s allows the explicit setting of the key for a principal S disallows the explicit setting of the key for a principal * All privileges (admcil). x All privileges (admcil); identical to “*”. The restrictions are a string of flags. Allowed restrictions are: [+ -]flagname flag is forced to indicated value. The permissible flags are the sameas the + and - flags for the kadmin addprinc andmodprinc commands. -clearpolicy policy is forced to clear -policy pol policy is forced to be pol expire timepwexpire timemaxlife timemaxrenewlife time associated value will be forced to MIN(time, requested value) The above flags act as restrictions on any add or modify operation which is allowed due to that ACL line. Here is an example of a kadm5.acl file. Note that order is important; permissions are determined by the first matching entry. */admin@ATHENA.MIT.EDU * joeadmin@ATHENA.MIT.EDU ADMCIL joeadmin/*@ATHENA.MIT.EDU il */root@ATHENA.MIT.EDU *@ATHENA.MIT.EDU cil *1/admin@ATHENA.MIT.EDU */*@ATHENA.MIT.EDU i */admin@EXAMPLE.COM * -maxlife 9h -postdateable In the above file, any principal in the ATHENA.MIT.EDU realm with an admin instance has all administrative privileges. The user joeadmin has all permissions with his admin instance, joeadmin/admin@ATHENA.MIT.EDU (matches the first line). He has no permissions at all with his null instance, joeadmin@ATHENA.MIT.EDU (matches the second line). His root instance has inquire and list permissions with any other principal that has the instance root. Any principal in ATHENA.MIT.EDU can inquire, list, or change the password of their admin instance, but not any other admin instance. Any principal in the realm ATHENA.MIT.EDU (except for joeadmin@ATHENA.MIT.EDU, as mentioned above) has inquire privileges. Finally, any principal with an admin instance in EXAMPLE.COM has all permissions, but any principal that they create or modify will not be able to get postdateable tickets or tickets with a life of longer than 9 hours. Adding or Modifying Principals To add a principal to the database, use the kadmin add_principal command, which requires the “add” administrative privilege. This function creates the new principal, prompting twice for a password, and, if neither the -policy nor -clearpolicy options are specified and the policy “default” exists, assigns it that policy. The syntax is: kadmin: add_principal [ options ] principal To modify attributes of a principal, use the kadmin modify_principal command, which requires the “modify” administrative privilege. The syntax is: kadmin: modify_principal [ options ] principal add_principal has the aliases addprinc and ankank was the short form of the equivalent command using the deprecated kadmin5 database administrative tool. It has been kept. modify_principal has the alias modprinc. The add_principal and modify_principal commands take the following switches: -x db_princ_args Denotes the database specific options.The options for LDAP database are: -x dn=<dn> Specifies the LDAP object that will contain the Kerberos principal being created. -x linkdn=<dn> Specifies the LDAP object to which the newly created Kerberos principal object will point to. -x containerdn=<container_dn> Specifies the container object under which the Kerberos principal is to be created. -x tktpolicy=<policy> Associates a ticket policy to the Kerberos principal. Specifying an empty stringvalue clears the ticket policy associated with the principal.Note:* dn and containerdn options are not valid while modifying the principal.* containerdn and linkdn options cannot be specified with dn option.* If dn or containerdn options are not specified while adding the principal, the principals are created under the prinicipal container configured in the realm or the realm container.* dn and containerdn should be within the subtrees or principal container configured in the realm. -expire date Sets the expiration date of the principal to date. -pwexpire date Sets the expiration date of the password to date. -maxlife maxlife Sets the maximum ticket life of the principal to maxlife. -maxrenewlife maxrenewlife Sets the maximum renewable life of tickets for the principal tomaxrenewlife. -kvno number Explicity sets the key version number to number. MITdoes not recommend doing this unless there is a specific reason. -policy policy Sets the policy used by this principal. (See .) Withmodify_principal, the current policy assigned to the principal isset or changed. With add_principal, if this option is notsupplied, the -clearpolicy is not specified, and the policy “default”exists, that policy is assigned. If a principal is created with nopolicy, kadmin will print a warning message. -clearpolicy For modify_principal, removes the current policy from aprincipal. For add_principal, suppresses the automaticassignment of the policy “default”. {-|+}allow_postdated The “-allow_postdated” option prohibits this principal from obtainingpostdated tickets. “+allow_postdated” clears this flag. In effect,“-allow_postdated” sets the KRB5_KDB_DISALLOW_POSTDATED flag on theprincipal in the database. {-|+}allow_forwardable The “-allow_forwardable” option prohibits this principal fromobtaining forwardable tickets. “+allow_forwardable” clears this flag.In effect, “-allow_forwardable” sets the KRB5_KDB_DISALLOW_FORWARDABLEflag on the principal in the database. {-|+}allow_renewable The “-allow_renewable” option prohibits this principal from obtainingrenewable tickets. “+allow_renewable” clears this flag. In effect,“-allow_renewable” sets the KRB5_KDB_DISALLOW_RENEWABLE flag on theprincipal in the database. {-|+}allow_proxiable The “-allow_proxiable” option prohibits this principal from obtainingproxiable tickets. “+allow_proxiable” clears this flag. In effect,“-allow_proxiable” sets the KRB5_KDB_DISALLOW_PROXIABLE flag. onthe principal in the database. {-|+}allow_dup_skey The “-allow_dup_skey” option disables user-to-user authentication forthis principal by prohibiting this principal from obtaining a sessionkey for another user. “+allow_dup_skey” clears this flag. In effect,“-allow_dup_skey” sets the KRB5_KDB_DISALLOW_DUP_SKEY flag on theprincipal in the database. {-|+}requires_preauth The “+requires_preauth” option requires this principal topreauthenticate before being allowed to kinit. -requires_preauth clearsthis flag. In effect, +requires_preauth sets theKRB5_KDB_REQUIRES_PRE_AUTH flag on the principal in the database. {-|+}requires_hwauth The “+requires_hwauth” flag requires the principal to preauthenticateusing a hardware device before being allowed to kinit.“-requires_hwauth” clears this flag. In effect, “+requires_hwauth”sets the KRB5_KDB_REQUIRES_HW_AUTH flag on the principal in thedatabase. {-|+}allow_svr The “-allow_svr” flag prohibits the issuance of service tickets forthis principal. “+allow_svr” clears this flag. In effect,“-allow_svr” sets the KRB5_KDB_DISALLOW_SVR flag on the principalin the database. {-|+}allow_tgs_req The “-allow_tgs_req” option specifies that a Ticket-Granting Service(TGS) request for a service ticket for this principal is not permitted.You will probably never need to use this option. “+allow_tgs_req”clears this flag. The default is “+allow_tgs_req”. In effect,“-allow_tgs_req” sets the KRB5_KDB_DISALLOW_TGT_BASED flag on theprincipal in the database. {-|+}allow_tix The “-allow_tix” option forbids the issuance of any tickets for thisprincipal. “+allow_tix” clears this flag. The default is“+allow_tix”. In effect, “-allow_tix” sets the KRB5_KDB_DISALLOW_ALL_TIX flag on the principal in the database. {-|+}needchange The “+needchange” option sets a flag in attributes field to force apassword change; “-needchange” clears it. The default is“-needchange”. In effect, “+needchange” sets theKRB5_KDB_REQUIRES_PWCHANGE flag on the principal in the database. {-|+}password_changing_service The “+password_changing_service” option sets a flag in the attributesfield marking this principal as a password change service. (Again, youwill probably never need to use this option.)“-password_changing_service” clears the flag. The default is“-password_changing_service”. In effect, the“+password_changing_service” option sets the KRB5_KDB_PWCHANGE_SERVICEflag on the principal in the database. -randkey Sets the key for the principal to a random value (add_principalonly). MIT recommends using this option for host keys. -pw password Sets the key of the principal to the specified string and does notprompt for a password (add_principal only). MIT doesnot recommend using this option. -e enc:salt... Uses the specified list of enctype-salttype pairs for setting the keyof the principal. The quotes are necessary if there are multipleenctype-salttype pairs. This will not function against kadmin daemonsearlier than krb5-1.2. See and for available types. If you want to just use the default values, all you need to do is: kadmin: addprinc jennifer WARNING: no policy specified for "jennifer@ATHENA.MIT.EDU"; defaulting to no policy. Principal "jennifer@ATHENA.MIT.EDU" created. kadmin: If you want to create a principal which is contained by a LDAP object, all you need to do is: kadmin: addprinc -x dn=cn=jennifer,o=mit jennifer WARNING: no policy specified for "jennifer@ATHENA.MIT.EDU"; defaulting to no policy. Principal "jennifer@ATHENA.MIT.EDU" created. kadmin: If you want to create a principal under a specific LDAP container and link to an existing LDAP object, all you need to do is: kadmin: addprinc -x containerdn=o=mit -x linkdn=cn=david,o=mit david WARNING: no policy specified for "david@ATHENA.MIT.EDU"; defaulting to no policy. Principal "david@ATHENA.MIT.EDU" created. kadmin: If you want to associate a ticket policy to a principal, all you need to do is: kadmin: modprinc -x tktpolicy=userpolicy david Principal "david@ATHENA.MIT.EDU" modified. kadmin: If, on the other hand, you want to set up an account that expires on January 1, 2000, that uses a policy called “stduser”, with a temporary password (which you want the user to change immediately), you would type the following. (Note: each line beginning with => is a continuation of the previous line.) kadmin: addprinc david -expire "1/1/2000 12:01am EST" -policy stduser => +needchange Principal "david@ATHENA.MIT.EDU" created. kadmin: If you will need cross-realm authentication, you need to add principals for the other realm's TGT to each realm. For example, if you need to do cross-realm authentication between the realms ATHENA.MIT.EDU and EXAMPLE.COM, you would need to add the principals ‘krbtgt/EXAMPLE.COM@ATHENA.MIT.EDU’ and ‘krbtgt/ATHENA.MIT.EDU@EXAMPLE.COM’ to both databases. You need to be sure the passwords and the key version numbers (kvno) are the same in both databases. This may require explicitly setting the kvno with the ‘-kvno’ option. See for more details. Deleting Principals To delete a principal, use the kadmin delete_principal command, which requires the “delete” administrative privilege. The syntax is: delete_principal [ -force ] principal delete_principal has the alias delprinc. The -force option causes delete_principal not to ask if you're sure. For example: kadmin: delprinc jennifer Are you sure you want to delete the principal "jennifer@ATHENA.MIT.EDU"? (yes/no): yes Principal "jennifer@ATHENA.MIT.EDU" deleted. Make sure that you have removed this principal from all ACLs before reusing. kadmin: Changing Passwords To change a principal's password use the kadmin change_password command, which requires the “modify” administrative privilege (unless the principal is changing his/her own password). The syntax is: change_password [ options ] principal The change_password option has the alias cpw. change_password takes the following options: -randkey Sets the key of the principal to a random value. -pw password Sets the password to the string password. MIT does notrecommend using this option. -e "enc:salt..." Uses the specified list of enctype-salttype pairs for setting the keyof the principal. The quotes are necessary if there are multipleenctype-salttype pairs. This will not function against kadmin daemonsearlier than krb5-1.2. See and for possible values. -keepold Keeps the previous kvno's keys around. There is no easy way to deletethe old keys, and this flag is usually not necessary except perhaps forTGS keys. Don't use this flag unless you know what you're doing. Thisoption is not supported for the LDAP database For example: kadmin: cpw david Password for david@ATHENA.MIT.EDU changed. kadmin: Note that change_password will not let you change the password to one that is in the principal's password history. Policies A policy is a set of rules governing passwords. Policies can dictate minimum and maximum password lifetimes, minimum number of characters and character classes a password must contain, and the number of old passwords kept in the database. Retrieving Policies To retrieve a policy, use the kadmin get_policy command, which requires the “inquire” administrative privilege. The syntax is: get_policy [ -terse ] policy The get_policy command has the alias getpol. For example: kadmin: get_policy admin Policy: admin Maximum password life: 180 days 00:00:00 Minimum password life: 00:00:00 Minimum password length: 6 Minimum number of password character classes: 2 Number of old keys kept: 5 Reference count: 17 kadmin: The reference count is the number of principals using that policy. The get_policy command has a -terse option, which lists each field as a quoted, tab-separated string. For example: kadmin: get_policy -terse admin admin 15552000 0 6 2 5 17 kadmin: Retrieving the List of Policies You can retrieve the list of policies with the kadmin list_policies command, which requires the “list” privilege. The syntax is: list_policies [ expression ] where expression is a shell-style glob expression that can contain the characters *, ?, and []. All policy names matching the expression are displayed. The list_policies command has the aliases listpols, get_policies, and getpols. For example: kadmin: listpols test-pol dict-only once-a-min test-pol-nopw kadmin: listpols t* test-pol test-pol-nopw kadmin: Adding or Modifying Policies To add a new policy, use the kadmin add_policy command, which requires the “add” administrative privilege. The syntax is: add_policy [ options ] policy_name To modify attributes of a principal, use the kadmin modify_policy command, which requires the “modify” administrative privilege. The syntax is: modify_policy [ options ] policy_name add_policy has the alias addpol. modify_poilcy has the alias modpol. The add_policy and modify_policy commands take the following switches: -maxlife time Sets the maximum lifetime of a password to time. -minlife time Sets the minimum lifetime of a password to time. -minlength length Sets the minimum length of a password to length characters. -minclasses number Requires at least number of character classes in a password. -history number Sets the number of past keys kept for a principal to number. This option is not supported for LDAP database. Note: The policies are created under realm container in the LDAP database. Deleting Policies To delete a policy, use the kadmin delete_policy command, which requires the “delete” administrative privilege. The syntax is: delete_policy [-force] policy_name The delete_policy command has the alias delpol. It prompts for confirmation before deletion. For example: kadmin: delete_policy guests Are you sure you want to delete the policy "guests"? (yes/no): yes kadmin: Note that you must cancel the policy from all principals before deleting it. The delete_policy command will fail if it is in use by any principals. Global Operations on the Kerberos Database The kdb5_util command is the primary tool for administrating the Kerberos database. The syntax is: kdb5_util command [ kdb5_util_options ] [ command_options ] The kdb5_util command takes the following options, which override the defaults specified in the configuration files: -r realm specifies the the Kerberos realm of the database. -d database_name specifies the name under which the principal database is stored. -k master_key_type specifies the key type of the master key in the database. -M master_key_name specifies the principal name of the master key in the database. -m indicates that the master database password should be read from the TTYrather than fetched from a file on disk. -sf stash_file specifies the stash file of the master database password -P password specifies the master database password. MIT does notrecommend using this option. Dumping a Kerberos Database to a File To dump a Kerberos database into a file, use the kdb5_util dump command on one of the KDCs. The syntax is: kdb5_util dump [ -old ] [ -b6 ] [ -b7 ] [ -ov ] [ -verbose ] [-mkey_convert] [-new_mkey_file] [ filename [ principals... ]] The kdb5_util dump command takes the following options: -old causes the dump to be in the Kerberos 5 Beta 5 and earlier dump format(“kdb5_edit load_dump version 2.0”). -b6 causes the dump to be in the Kerberos 5 Beta 6 format (“kdb5_editload_dump version 3.0”). -b7 causes the dump to be in the Kerberos 5 Beta 7 format (“kdbt_editload_dump version 4”). -ov causes the dump to be in ovsec_adm_export format. Currently, the onlyway to preserve per-principal policy information is to use this inconjunction with a normal dump. -verbose causes the name of each principal and policy to be printed as it isdumped. -mkey_convert prompts for a new master password, and then dumps the database withall keys reencrypted in this new master key -new_mkey_file reads a new key from the default keytab and then dumps the databasewith all keys reencrypted in this new master key For example: shell% kdb5_util dump dumpfile shell% shell% kbd5_util dump -verbose dumpfile kadmin/admin@ATHENA.MIT.EDU krbtgt/ATHENA.MIT.EDU@ATHENA.MIT.EDU kadmin/history@ATHENA.MIT.EDU K/M@ATHENA.MIT.EDU kadmin/changepw@ATHENA.MIT.EDU shell% If you specify which principals to dump, you must use the full principal, as in the following example. (The line beginning with => is a continuation of the previous line.): shell% kdb5_util dump -verbose dumpfile K/M@ATHENA.MIT.EDU => kadmin/admin@ATHENA.MIT.EDU kadmin/admin@ATHENA.MIT.EDU K/M@ATHENA.MIT.EDU shell% Otherwise, the principals will not match those in the database and will not be dumped: shell% kdb5_util dump -verbose dumpfile K/M kadmin/admin shell% If you do not specify a dump file, kdb5_util will dump the database to the standard output. There is currently a bug where the default dump format omits the per-principal policy information. In order to dump all the data contained in the Kerberos database, you must perform a normal dump (with no option flags) and an additional dump using the “-ov” flag to a different file. Restoring a Kerberos Database from a Dump File To restore a Kerberos database dump from a file, use the kdb5_util load command on one of the KDCs. The syntax is: kdb5_util load [ -old ] [ -b6 ] [ -b7 ] [ -ov ] [ -verbose ] [ -update ] [ -hash ] dumpfilename dbname [ admin_dbname ] The kdb5_util load command takes the following options: -old requires the dump to be in the Kerberos 5 Beta 5 and earlier dump format(“kdb5_edit load_dump version 2.0”). -b6 requires the dump to be in the Kerberos 5 Beta 6 format (“kdb5_editload_dump version 3.0”). -b7 requires the dump to be in the Kerberos 5 Beta 7 format (“kdb5_editload_dump version 4”). -ov requires the dump to be in ovsec_adm_export format. -verbose causes the name of each principal and policy to be printed as it isloaded. -update causes records from the dump file to be updated in or added to theexisting database. This is useful in conjunction with anovsec_adm_export format dump if you want to preserve per-principalpolicy information, since the current default format does not containthis data. -hash causes the database to be stored as a hash rather than a binary tree. For example: shell% kdb5_util load dumpfile principal shell% shell% kdb5_util load -update dumpfile principal shell% If the database file exists, and the -update flag was not given, kdb5_util will overwrite the existing database. Creating a Stash File A stash file allows a KDC to authenticate itself to the database utilities, such as kadmin, kadmind, krb5kdc, and kdb5_util. To create a stash file, use the kdb5_util stash command. The syntax is: kdb5_util stash [ -f keyfile ] For example: shell% kdb5_util stash kdb5_util: Cannot find/read stored master key while reading master key kdb5_util: Warning: proceeding without master key shell% If you do not specify a stash file, kdb5_util will stash the key in the file specified in your kdc.conf file. Creating and Destroying a Kerberos Database If you need to create a new Kerberos database, use the kdb5_util create command. The syntax is: kdb5_util create [ -s ] If you specify the ‘-s’ option, kdb5_util will stash a copy of the master key in a stash file. (See .) For example: shell% /usr/local/sbin/kdb5_util -r ATHENA.MIT.EDU create -s kdb5_util: No such file or directory while setting active database to => '/usr/local/var/krb5kdc/principal' Initializing database '/usr/local/var/krb5kdc/principal' for => realm 'ATHENA.MIT.EDU', master key name 'K/M@ATHENA.MIT.EDU' You will be prompted for the database Master Password. It is important that you NOT FORGET this password. shell% If you need to destroy the current Kerberos database, use the kdb5_util destroy command. The syntax is: kdb5_util destroy [ -f ] The destroy command destroys the database, first overwriting the disk sectors and then unlinking the files. If you specify the ‘-f’ option, kdb5_util will not prompt you for a confirmation before destroying the database. shell% /usr/local/sbin/kdb5_util -r ATHENA.MIT.EDU destroy OK, deleting database '/usr/local/var/krb5kdc/principal'... shell% Global Operations on the Kerberos LDAP Database The kdb5_ldap_util is the primary tool for administrating the Kerberos LDAP database. It allows an administrator to manage realms, Kerberos services ( KDC and Admin Server) and ticket policies. The syntax is: kdb5_ldap_util [ -D user_dn [ -w passwd] ] [ -H ldap_uri ] command [command_options] -D user_dn Specifies the Distinguished Name (DN) of the user who has sufficient rights to perform the operation on the LDAP server. -w passwd Specifies the password of user_dn. This option is not recommended. -H ldap_uri Specifies the URI of the LDAP server. It is recommended to use ldapi:// or ldaps:// to connect to the LDAP server. Creating a Kerberos Realm If you need to create a new realm, use the command as follows: create [ -r realm ] [ -subtrees subtree_dn_list ] [ -sscope search_scope ] [ -containerref container_reference_dn ] [ -k mkeytype ] [ -m | -P password ][ -sf stashlename ] [ -s ] [ -maxtktlife max_ticket_life ] [ -maxrenewlife max_renewable_ticket_life ] [ ticket_flags ] Options to create realm in directory are as follows: -r realm Specifies the Kerberos realm of the database; by default the realm returned by ‘krb5_default_local_realm’ (3) is used. -subtrees subtree_dn_list Specifies the list of subtrees containing principals of a realm. The list contains the DN of the subtree objects separated by colon(:). -sscope search_scope Specifies the scope for searching the principals under the subtree. The possible values are 1 or one (one level), 2 or sub (subtree). -containerref container_reference_dn Specfies the DN of the container object in which the principals of a realm will be created. If the container reference is not configured for a realm, the principals will be created in the realm container. -k mkeytype Specifies the key type of the master key in the database; the defaultis that given in kdc.conf. -m Specifies that the master database password should be read from the TTY rather than fetched from a file on disk. -p password Specifies the master database password. This option is not recommended. -sf stashfilename Specifies the stash file of the master database password. -s Specifies that the stash file is to be created. -maxtktlife max_ticket_life Specifies maximum ticket life for principals in this realm. This value is used, if it is not set on the principal. -maxrenewlife max_renewable_ticket_life Specifies maximum renewable life of tickets for principals in this realm. This value is used, if it is not set on the principal. ticket_flags Specifies the ticket flags. If this option is not specified, by default, none of the flags are set. This means all the ticket options will be allowed and no restriction will be set. This value is used, if it is not set on the principal.The various flags are: {-|+}allow_postdated -allow_postdated prohibits principals from obtaining postdated tickets. (Sets the ‘KRB5_KDB_DISALLOW_POSTDATED’ flag.).+allow_postdated clears this flag. {-|+}allow_forwardable -allow_forwardable prohibits principals from obtaining forwardable tickets. (Sets the‘KRB5_KDB_DISALLOW_FORWARDABLE’ flag.) +allow_forwardable clears this flag. {-|+}allow_renewable -allow_renewable prohibits principals from obtaining renewable tickets. (Sets the ‘KRB5_KDB_DISALLOW_RENEWABLE’ flag.) +allow_renewable clears this flag. {-|+}allow_proxiable -allow_proxiable prohibits principals from obtaining proxiable tickets. (Sets the ‘KRB5_KDB_DISALLOW_PROXABLE’ flag.) +allow_proxiable clears this flag. {-|+}allow_dup_skey -allow_dup_skey disables user-to-user authentication forprincipals by prohibiting principals from obtaining a sessions key foranother user. (Sets the ‘KRB5_KDB_DISALLOW_DUP_SKEY’ flag.)+allow_dup_skey clears this flag. {-|+}requires_preauth +requires_preauth requires principals to preauthenticate before being allowed to kinit. (Sets the ‘KRB5_KDB_REQURES_PRE_AUTH’ flag.) -requires_preauth clears this flag. {-|+}requires_hwauth +requires_hwauth requires principals to preauthenticate using ahardware device before being allowed to kinit. (Sets the‘KRB5_KDB_REQURES_HW_AUTH’ flag.) -requires_hwauth clearsthis flag. {-|+}allow_svr -allow_svr prohibits the issuance of service tickets for principals. (Sets the ‘KRB5_KDB_DISALLOW_SVR’ flag.) +allow_svr clears this flag. {-|+}allow_tgs_req -allow_tgs_req specifies that a Ticket-Granting Service(TGS) request for a service ticket for principals is notpermitted. This option is useless for mostthings.+allow_tgs_req clears this flag. The default is+allow_tgs_req. In effect, -allow_tgs_req sets the‘KRB5_KDB_DISALLOW_TGT_BASED’ flag on principals in thedatabase. {-|+}allow_tix -allow_tix forbids the issuance of any tickets forprincipals. +allow_tix clears this flag. The default is+allow_tix. In effect, -allow_tix sets the‘KRB5_KDB_DISALLOW_ALL_TIX’ flag on principals in the database. {-|+}needchange +needchange sets a flag in attributes field to force a password change;-needchange clears it. The default is -needchange. In effect,+needchange sets the ‘KRB5_KDB_REQURES_PWCHANGE’ flag onprincipals in the database. {-|+}password_changing_service +password_changing_service sets a flag in the attributes fieldmarking principal as a password change service principal (useless formost things). -password_changing_service clears the flag. Thisflag intentionally has a long name. The default is-password_changing_service. In effect,+password_changing_service sets the‘KRB5_KDB_PWCHANGE_SERVICE’ flag on principals in the database. shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu create -sscope -subtree ou=users,o=org -r ATHENA.MIT.EDU Password for "cn=admin,o=org": Initializing database for realm 'ATHENA.MIT.EDU' You will be prompted for the database Master Password. It is important that you NOT FORGET this password. Enter KDC database master key: Re-enter KDC database master key to verify: shell% eDirectory Options -kdcdn kdc_servce_list Specifies the list of KDC service objects serving the realm. The list contains the DNs of the KDC service objects separated by colon(:). -admindn admin_service_list Specifies the list of Administration service objects serving the realm. The list contains the DNs of the Administration service objects separated by colon(:). shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu create -sscope -subtree ou=users,o=org -kdcdn cn=krbkdc,o=org -admindn cn=krbadmin,o=org -r ATHENA.MIT.EDU Password for "cn=admin,o=org": Initializing database for realm 'ATHENA.MIT.EDU' You will be prompted for the database Master Password. It is important that you NOT FORGET this password. Enter KDC database master key: Re-enter KDC database master key to verify: shell% Modifying a Kerberos Realm If you need to modify a realm, use the command as follows: modify [ -r realm ] [ -subtrees subtree_dn ] [ -sscope search_scope ][ -containerref container_reference_dn ] [ -maxtktlife max_ticket_life ][ -maxrenewlife max_renewable_ticket_life ] [ -ticket_flags ] Options to modify realm in directory are as follows: -r realm Specifies the Kerberos realm of the database; by default the realm returned by krb5_default_local_realm (3) is used. -subtrees subtree_dn_list Specifies the list of subtrees containing principal objects in the realm.The list contains the DN of the subtree objects separated by colon(:). This list replaces the existing list. -sscope search_scope Specifies the scope for searching the principals under the subtrees. The possible values are 1 or one (one level), 2 or sub (subtrees). -containerref container_reference_dn Specifies the Distinguished Name (DN) of the container object in which the principals of a realm will be created. -maxtktlife max_ticket_life Specifies maximum ticket life for principals in this realm. This value is used, if it is not set on the principal. -maxrenewlife max_renewable_ticket_life Specifies maximum renewable life of tickets for principals in this realm. This value is used, if it is not set on the principal. -ticket_flags Specifies the ticket flags. If this option is not specified, by default, none of the flags are set. This means all the ticket options will be allowed and no restriction will be set. This value is used, if it is not set on the principal.The various flags are: {-|+}allow_postdated -allow_postdated prohibits principals from obtaining postdated tickets. (Sets the ‘KRB5_KDB_DISALLOW_POSTDATED’ flag.).+allow_postdated clears this flag. {-|+}allow_forwardable -allow_forwardable prohibits principals from obtaining forwardable tickets.(Sets the ‘KRB5_KDB_DISALLOW_FORWARDABLE’ flag.) +allow_forwardable clears this flag. {-|+}allow_renewable -allow_renewable prohibits principals from obtaining renewable tickets. (Sets the ‘KRB5_KDB_DISALLOW_RENEWABLE’ flag.) +allow_renewable clears this flag. {-|+}allow_proxiable -allow_proxiable prohibits principals from obtaining proxiable tickets. (Sets the ‘KRB5_KDB_DISALLOW_PROXABLE’ flag.) +allow_proxiable clears this flag. {-|+}allow_dup_skey -allow_dup_skey Disables user-to-user authentication for principals by prohibiting principals from obtaining a sessions key for another user. (Sets the ‘KRB5_KDB_DISALLOW_DUP_SKEY’ flag.). +allow_dup_skey clears This flag. {-|+}requires_preauth +requires_preauth requires principals to preauthenticate before being allowed to kinit. Sets the‘KRB5_KDB_REQURES_PRE_AUTH’ flag.-requires_preauth clears this flag. {-|+}requires_hwauth +requires_hwauth requires principals to preauthenticate using a hardware device before being allowed to kinit. (Sets the‘KRB5_KDB_REQURES_HW_AUTH’ flag.)-requires_hwauth clears this flag. {-|+}allow_svr -allow_svr prohibits the issuance of service tickets for principals. (Sets the ‘KRB5_KDB_DISALLOW_SVR’ flag.) +allow_svr clears This flag. {-|+}allow_tgs_req -allow_tgs_req specifies that a Ticket-Granting Service (TGS) request for a service ticket for principals is not permitted. This option is useless for most things.+allow_tgs_req clears this flag.The default is. +allow_tgs_req. In effect,-allow_tgs_req sets the ‘KRB5_KDB_DISALLOW_TGT_BASED’ flagon principals in the database. {-|+}allow_tix -allow_tix forbids the issuance of any tickets forprincipals. +allow_tix clears this flag. The default is+allow_tix. In effect, -allow_tix sets the‘KRB5_KDB_DISALLOW_ALL_TIX’ flag on principals in the database. {-|+}needchange +needchange sets a flag in attributes field to force a password change; -needchange clears it.The default is -needchange. In effect,+needchange setsthe ‘KRB5_KDB_REQURES_PWCHANGE’ flag on principals in thedatabase. {-|+}password_changing_service +password_changing_service sets a flag in the attributes field marking principal as a password change service principal (useless for most things).-password_changing_service clears the flag. This flag intentionally has a long name. The default is -password_changing_serviceIn effect, +password_changing_service sets the ‘KRB5_KDB_PWCHANGE_SERVICE’ flag on principals in the database. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu modify -r ATHENA.MIT.EDU +requires_preauth Password for "cn=admin,o=org": shell% eDirectory Options -kdcdn kdc_service_list Specifies the list of KDC service objects serving the realm. The list contains the DNs of the KDC service objects separated by a colon (:). This list replaces the existing list. -clearkdcdn kdc_service_list Specifies the list of KDC service objects that need to be removed from the existing list. The list contains the DNs of the KDC service objects separated by a colon (:). -addkdcdn kdc_service_list Specifies the list of KDC service objects that need to be added to the existing list. The list contains the DNs of the KDC service objects separated by a colon (:). -admindn admin_service_list Specifies the list of Administration service objects serving the realm. The list contains the DNs of the Administration service objects separated by a colon (:). This list replaces the existing list. -clearadmindn admin_service_list Specifies the list of Administration service objects that need to be removed from the existing list. The list contains the DNs of the Administration service objects separated by a colon (:). -addadmindn admin_service_list Specifies the list of Administration service objects that need to be added to the existing list. The list contains the DNs of the Administration service objects separated by a colon (:). Retrieving Information about a Kerberos Realm view [-r realm] Displays the attributes of a realm. Option is as follows: -r realm specifies the Kerberos realm of the database; by default the realm returned by krb5_default_local_realm (3)is used. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu view -r ATHENA.MIT.EDU Password for "cn=admin,o=org": Realm Name: ATHENA.MIT.EDU Subtree: ou=users,o=org Subtree: ou=servers,o=org SearchScope: ONE Maximum ticket life: 0 days 01:00:00 Maximum renewable life: 0 days 10:00:00 Ticket flags: DISALLOW_FORWARDABLE shell% Destroying a Kerberos Realm destroy [-f] [-r realm] Destroys an existing realm. Options are as follows: -f If specified, will not prompt the user for confirmation. -r realm specifies the Kerberos realm of the database; by default the realm returned by‘krb5_default_local_realm’ (3)is used. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldap-server1.mit.edu destroy -r ATHENA.MIT.EDU Password for "cn=admin,o=org": Deleting KDC database of 'ATHENA.MIT.EDU', are you sure? type 'yes' to confirm)? Yes OK, deleting database of 'ATHENA.MIT.EDU'... shell% Listing available Kerberos Realms list This option lists the name of the realms. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu list Password for "cn=admin,o=org": ATHENA.MIT.EDU OPENLDAP.MIT.EDU MEDIA-LAB.MIT.EDU shell% Stashing Service Object's Password stashsrvpw [-f filename] servicedn This command allows an administrator to store the password of service object in a file. The KDC and Administration server uses this password to authenticate to the LDAP server. Options are as follows: -f filename Specifies the complete path of the service password file. By default, /usr/local/var/service_passwd is used. servicedn Specifies the Distinguished Name (DN) of the service object whose password is to be stored in file. For example: shell% kdb5_ldap_util stashsrvpw -f /home/andrew/conf_keyle cn=service-kdc,o=org Password for "cn=service-kdc,o=org" : Re-enter password for "cn=service-kdc,o=org" : shell% Creating and Modifying a Ticket Policy This command creates a ticket policy in directory. create_policy [ -r realm ] [ -maxrenewlife max_renewable_ticket_life ] [ ticket_flags ] policy_name Ticket policy objects are created under the realm container. This command modifies a ticket policy in directory. modify_policy [ -r realm ] [ -maxrenewlife max_renewable_ticket_life ] [ ticket_flags ] policy_name Options are as follows: -r realm Specifies the Kerberos realm of the database; by default the realm returned by krb5_default_local_realm(3) is used. -maxtktlife max_ticket_life specifies maximum ticket life for principals. -maxrenewlife max_renewable_ticket_life specifies maximum renewable life of tickets for principals. ticket_flags Specifies the ticket flags. If this option is not specified, by default, none of the flags are set. This means all the ticket options will be allowed and no restriction will be set.The various flags are: {-|+}allow_postdated -allow_postdated prohibits principals from obtaining postdated tickets. (Sets the ‘KRB5_KDB_DISALLOW_POSTDATED’ flag.).+allow_postdated clears this flag. {-|+}allow_forwardable -allow_forwardable prohibits principals from obtaining forwardable tickets. (Sets the‘KRB5_KDB_DISALLOW_FORWARDABLE’ flag.) +allow_forwardable clears this flag. {-|+}allow_renewable -allow_renewable prohibits principals from obtaining renewable tickets. (Sets the ‘KRB5_KDB_DISALLOW_RENEWABLE’ flag.) +allow_renewable clears this flag. {-|+}allow_proxiable -allow_proxiable prohibits principals from obtaining proxiable tickets. (Sets the ‘KRB5_KDB_DISALLOW_PROXABLE’ flag.) +allow_proxiable clears this flag. {-|+}allow_dup_skey -allow_dup_skey Disables user-to-user authentication for principals by prohibiting principals from obtaining a sessions key for another user. (Sets the ‘KRB5_KDB_DISALLOW_DUP_SKEY’ flag.). +allow_dup_skey clears This flag. {-|+}requires_preauth +requires_preauth requires principals to preauthenticate before being allowed to kinit. (Sets the ‘KRB5_KDB_REQURES_PRE_AUTH’ flag.)-requires_preauth clears this flag. {-|+}requires_hwauth +requires_hwauth requires principals to preauthenticate using ahardware device before being allowed to kinit. (Sets the‘KRB5_KDB_REQURES_HW_AUTH’ flag.) -requires_hwauth clearsthis flag. {-|+}allow_svr -allow_svr prohibits the issuance of service tickets for principals. (Sets the ‘KRB5_KDB_DISALLOW_SVR’ flag.) +allow_svr clears This flag. {-|+}allow_tgs_req -allow_tgs_req specifies that a Ticket-Granting Service (TGS) request for a service ticket for principals is not permitted. This option is useless for most things.+allow_tgs_req clears this flag.The default is +allow_tgs_req. In effect,-allow_tgs_req sets the ‘KRB5_KDB_DISALLOW_TGT_BASED’ flagon principals in the database. {-|+}allow_tix -allow_tix forbids the issuance of any tickets forprincipals. +allow_tix clears this flag. The default is+allow_tix. In effect, -allow_tix sets the‘KRB5_KDB_DISALLOW_ALL_TIX’ flag on principals in the database. {-|+}needchange +needchange sets a flag in attributes field to force a password change;-needchange clears it. The default is -needchange. Ineffect, +needchange sets the ‘KRB5_KDB_REQURES_PWCHANGE’flag on principals in the database. {-|+}password_changing_service +password_changing_service sets a flag in the attributes fieldmarking principal as a password change service principal (useless formost things). -password_changing_service clears the flag.This flag intentionally has a long name. The default is-password_changing_service. In effect,+password_changing_service sets the‘KRB5_KDB_PWCHANGE_SERVICE’ flag on principals in the database. policy_name Specifies the name of the ticket policy. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu create_policy -r ATHENA.MIT.EDU -maxtktlife "1 day" -maxrenewlife "1 week" -allow_forwardable usertktpolicy Password for "cn=admin,o=org": shell% Retrieving Information About a Ticket Policy view_policy [-r realm] policy_nameview_policy This option displays the attributes of a ticket policy. Option is as follows: -r realm Specifies the Kerberos realm of the database; by default the realm returned by krb5_default_local_realm(3) is used. policy_name Specifies the name of the ticket policy. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu view_policy -r ATHENA.MIT.EDU usertktpolicy Password for "cn=admin,o=org": Ticket policy: usertktpolicy Maxmum ticket life: 0 days 01:00:00 Maxmum renewable life: 0 days 10:00:00 Ticket flags: DISALLOW_FORWARDABLE REQUIRES_PWCHANGE shell% Destroying a Ticket Policy destroy_policy [-force] [-r realm] policy_name Destroys an existing ticket policy. Options are as follows: -force Forces the deletion of the policy object. If not specified, will be prompted for confirmation while deleting the policy. Enter yes to confirm the deletion. -r realm Specifies the Kerberos realm of the database; by default the realm returned by krb5_default_local_realm(3) is used. policy_name Specifies the name of the ticket policy. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu destroy_policy -r ATHENA.MIT.EDU usertktpolicy Password for "cn=admin,o=org": This will delete the policy object 'usertktpolicy', are you sure? (type 'yes' to confirm)? Yes ** policy object 'usertktpolicy' deleted. shell% Listing available Ticket Policies list_policy [-r realm] Lists the name of ticket policies in a realm.Option are as follows: -r realm Specifies the Kerberos realm of the database; by default the realm returned by krb5_default_local_realm(3) is used. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu list_policy -r ATHENA.MIT.EDU Password for "cn=admin,o=org": usertktpolicy tempusertktpolicy krbtktpolicy shell% Creating a Service Object (eDirectory) create_service -kdc|-admin|-pwd [ -servicehost service_host_list ] [ -realm realm_list ] [ -randpw | -fileonly ] [ -filename ] service_dn Creates a service object in directory and assigns appropriate rights on the container holding kerberos data. Options are as follows: -kdc Specifies the KDC service -admin Specifies the Administration service -pwd Specifies the Password service -servicehost service_host_list Specifies the list of entries separated by a colon (:). Each entry consists of the hostname or IP address of the server hosting the service, transport protocol and the port number of the service separated by a pound sign (#).For example, server1#tcp#88:server2#udp#89. -realm realm_list Specifies the list of realms that are to be associated with this service. The list contains the name of the realms separated by a colon (:). -randpw Generates and sets a random password. This option is used to set the random password for the service object in directory and also to store it in the file. -fileonly option cannot be used with -randpw option. -fileonly Stores the password only in a file and not in directory. The -randpw option can not be used when -fileonly option is specified. -f filename Specifies the complete path of the file where the service object password is stashed. If this option is not specified, the default file will be /usr/local/var/service_passwd service_dn Specifies the Distinguished Name (DN) of the Kerberos service to be created.For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu create_service -kdc -randpw -f /home/andrew/service_passwd cn=service-kdc,o=org Password for "cn=admin,o=org": File does not exist. Creating the file /home/andrew/service_passwd... shell% Modifying a Service Object (eDirectory) modify_service [ -servicehost service_host_list |[ -clearservicehost service_host_list ] [ -addservicehost service_host_list ]] [ -realm realm_list | [ -clearrealm realm_list ] [ -addrealm realm_list ]] service_dn Modifies the attributes of a service and assigns appropriate rights, if realm associations are changed. Options are as follows: -servicehost service_host_list List of entries separated by a colon (:) where each entry consists of host name or IP address of the server hosting the service, transport protocol, and port number of the service separated by a pound sign (#). This list replaces the existing list.For example, server1#tcp#88:server2#udp#89 -clearservicehost service_host_list Specifies the list of servicehost entries to be removed from the existing list. This is a colon separated list. -addservicehost service_host_list Specifies the list of servicehost entries to be added to the existing list. This is a colon separated list. -realm realm_list Specifies the list of realms that are to be associated with this service. The list contains the name of the realms separated by a colon (:). This list replaces the existing list. -clearrealm realm_list Specifies the list of realms to be removed from the existing list. The list contains the name of the realms separated by a colon (:). -addrealm realm_list Specifies the list of realms to be added to the existing list. The list contains the name of the realms separated by a colon (:). service_dn Specifies the Distinguished Name (DN) of the Kerberos service to be modified. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu modify_service -realm ATHENA.MIT.EDU cn=service-kdc,o=org Password for "cn=admin,o=org": Changing rights for the service object. Please wait ... done shell% Retrieving Service Object Information (eDirectory) view_service service_dn Displays the attributes of a service. Options are as follows: service_dn Specifies the Distinguished name (DN) of the Kerberos service to be viewed. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu view_service cn=service-kdc,o=org Password for "cn=admin,o=org": Service dn: cn=service-kdc,o=org Service type: kdc Service host list: Realm DN list: cn=ATHENA.MIT.EDU,cn=Kerberos,o=org shell% Destroying a Service Object (eDirectory) destroy_service [ -force ] [ -f stashfilename ] service_dn Destroys an existing service. Options are as follows : -force If specified, will not prompt for user's confirmation, instead will force destruction of service. -f stashfilename Complete path of the service password file from where the entry corresponding to the service_dn needs to be removed. service_dn Distinguished Name (DN) of the Kerberos service to be destroyed. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu destroy_service cn=service-kdc,o=org Password for "cn=admin,o=org": This will delete the service object 'cn=service-kdc,o=org', are you sure? (type 'yes' to confirm)? Yes ** service object 'cn=service-kdc,o=org' deleted. shell% Listing Available Service Objects (eDirectory) list_service [-basedn base_dn] Lists the name of services under a given base in directory. Options is as follows: -basedn base_dn Specifies the base DN for searching the policies, limiting the search to a particular subtree. If this option is not provided, LDAP Server specific search base will be used. For e.g., in the case of OpenLDAP, value of defaultsearchbase from slapd.conf file will be used, where as in the case of eDirectory, the default value for the base DN is Root. For example: shell% kdb5_ldap_util -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu list_service Password for "cn=admin,o=org": cn=service-kdc,o=org cn=service-adm,o=org cn=service-pwd,o=org shell% Passwords for Service Objects (eDirectory) setsrvpw [-randpw|-fileonly][-f filename] service_dn Allows an administrator to set password for service objects such as KDC and Administration server in eDirectory and store them in a file. The -fileonly command stores the password in a file and not in the eDirectory object. Options are as follows: -randpw Generates and sets a random password on the directory object and stores it in the file. The -fileonly option can not be used if -randpw option is already specified. -fileonly Stores the password only in a file and not in eDirectory. The -randpw option can not be used when -fileonly option is specified. -f filename Specifies the complete path of the file where the service object password is stashed. If this option is not specified, the default file will be /usr/local/var/service_passwd. service_dn Specifies the Distinguished Name (DN) of the service object whose password is to be set. For example: shell% kdb5_ldap_util setsrvpw -D cn=admin,o=org -H ldaps://ldap-server1.mit.edu setsrvpw -f /home/andrew/conf_keyfile cn=service-kdc,o=org Password for "cn=admin,o=org": Password for "cn=service-kdc,o=org": Re-enter password for "cn=service-kdc,o=org": shell% Cross-realm Authentication In order for a KDC in one realm to authenticate Kerberos users in a different realm, it must share a key with the KDC in the other realm. In both databases, there must be krbtgt service principals for realms. These principals should all have the same passwords, key version numbers, and encryption types. For example, if the administrators of ATHENA.MIT.EDU and EXAMPLE.COM wanted to authenticate across the realms, they would run the following commands on the KDCs in both realms: shell%: kadmin.local -e "des3-hmac-sha1:normal des-cbc-crc:v4" kadmin: add_princ -requires_preauth krbtgt/ATHENA.MIT.EDU@EXAMPLE.COM Enter password for principal krbtgt/ATHENA.MIT.EDU@EXAMPLE.COM: Re-enter password for principal krbtgt/ATHENA.MIT.EDU@EXAMPLE.COM: kadmin: add_princ -requires_preauth krbtgt/EXAMPLE.COM@ATHENA.MIT.EDU Enter password for principal krbtgt/EXAMPLE.COM@ATHENA.MIT.EDU: Enter password for principal krbtgt/EXAMPLE.COM@ATHENA.MIT.EDU: kadmin: Even if most principals in a realm are generally created with the requires_preauth flag enabled, this flag is not desirable on cross-realm authentication keys because doing so makes it impossible to disable preauthentication on a service-by-service basis. Disabling it as in the example above is recommended. It is also very important that these principals have good passwords. MIT recommends that TGT principal passwords be at least 26 characters of random ASCII text. Changing the krbtgt Key A Kerberos Ticket Granting Ticket (TGT) is a service ticket for the principal krbtgt/REALM. The key for this principal is created when the Kerberos database is initialized and need not be changed. However, it will only have the encryption types supported by the KDC at the time of the initial database creation. To allow use of newer encryption types for the TGT, this key has to be changed. Changing this key using the normal kadmin change_password command would invalidate any previously issued TGTs. Therefore, when changing this key, normally one should use the -keepold flag to change_password to retain the previous key in the database as well as the new key. For example: kadmin: change_password -randkey -keepold krbtgt/ATHENA.MIT.EDU@ATHENA.MIT.EDU There is currently no way to remove the old key without running change_password without the -keepold flag (and thereby invalidating all existing TGTs). After issuing this command, the old key is still valid and is still vulnerable to (for instance) brute force attacks. To completely retire an old key or encryption type, it's therefore currently necessary to declare a flag day, run change_password without the -keepold flag, and force all users to acquire new tickets. Configuring Kerberos with OpenLDAP back-end Set up SSL on the OpenLDAP server and client to ensure securecommunication when the KDC service and LDAP server are on differentmachines. ldapi:// can be used if the LDAP server and KDCservice are running on the same machine. Setting up SSL on the OpenLDAP server: Get a CA certificate using OpenSSL tools Configure OpenLDAP server for using SSL/TLSFor the latter, you need to specify the location of CA certificate location in slapd.conf file.Refer to the following link for more information:http://www.openldap.org/doc/admin23/tls.html Setting up SSL on OpenLDAP Client: For the KDC and Admin Server, you need to do the client-side configuration in ldap.conf.For example, TLS_CACERT /etc/openldap/certs/cacert.pem Include the Kerberos schema file (kerberos.schema) in theconfiguration file (slapd.conf) on the LDAP Server, by providing thelocation where it is stored. include /etc/openldap/schema/kerberos.schema Configure the LDAP server ACLs to enable the KDC and Admin server toread and write the Kerberos data. Sample access control information access to dn.base="" by * read access to dn.base="cn=Subschema" by * read access to attrs=userPassword,userPKCS12 by self write by * auth access to attrs=shadowLastChange by self write by * read # Providing access to realm subtree access to dn.subtree= "o=mit" by dn.exact= "cn=kdc-service,o=mit" read by dn.exact= "cn=adm-service,o=mit" write by * none # Providing access to realm container access to dn.subtree= "cn=MIT.EDU,cn=Kerberos,o=mit" by dn.exact= "cn=kdc-service,o=mit" read by dn.exact= "cn=adm-service,o=mit" write by * none access to * by * read The above list provides the access control information for the KDC andAdmin service object for the realm container and the realmsubtree. Thus if the realm subtree or the service objects for a realmare changed then this information should be updated. Start the LDAP server as follows: slapd -h "ldapi:/// ldaps:///" Modify the krb5.conf file to include LDAP specific items listed below: ‘realms’ ‘database_module’ ‘dbmodules’ ‘db_library’ ‘db_module_dir’ ‘ldap_kdc_dn’ ‘ldap_kadmind_dn’ ‘ldap_service_password_file’ ‘ldap_servers’ ‘ldap_conns_per_server’ For the sample krb5.conf file, refer to .For more details, refer to the section krb5.conf Create the realm using ‘kdb5_ldap_util’. kdb5_ldap_util -D cn=admin,o=mit create -subtrees o=mit -r MIT.EDU -s Before executing the command, make sure that the subtree mentioned above ‘(o=mit)’ exists.For more information, refer to the section Global Operations on the Kerberos LDAP Database.The realm object is created under the ldap_kerberos_container_dn specified in the configuration file. This operation will also create the Kerberos container, if not present already. This will be used to store information related to all realms. Stash the password of the service object used by the KDC andAdministration service to bind to the LDAP server using the stashsrvpwcommand of kdb5_ldap_util. The object DN should be the same asldap_kdc_dn and ldap_kadmind_dn values specified in the krb5.conffile. kdb5_ldap_util -D cn=admin,o=mit stashsrvpw -f /etc/kerberos/service.keyfile cn=krbadmin,o=mit Add krb5principalname to the indexes in slapd.conf to speed up the access. Application Servers If you need to install the Kerberos V5 programs on an application server, please refer to the Kerberos V5 Installation Guide. Once you have installed the software, you need to add that host to the Kerberos database (see ), and generate a keytab for that host, that contains the host's key. You also need to make sure the host's clock is within your maximum clock skew of the KDCs. Keytabs A keytab is a host's copy of its own keylist, which is analogous to a user's password. An application server that needs to authenticate itself to the KDC has to have a keytab that contains its own principal and key. Just as it is important for users to protect their passwords, it is equally important for hosts to protect their keytabs. You should always store keytab files on local disk, and make them readable only by root, and you should never send a keytab file over a network in the clear. Ideally, you should run the kadmin command to extract a keytab on the host on which the keytab is to reside. Adding Principals to Keytabs To generate a keytab, or to add a principal to an existing keytab, use the ktadd command from kadmin, which requires the “inquire” administrative privilege. (If you use the -glob princ_exp option, it also requires the “list” administrative privilege.) The syntax is: ktadd [ -k[eytab] keytab ] [ -q ] [ -e key:salt_list ] [ principal | -glob princ_exp ] [ … ] The ktadd command takes the following switches: -k[eytab] keytab use keytab as the keytab file. Otherwise, ktadd will use thedefault keytab file (/etc/krb5.keytab). -e "enc:salt..." Uses the specified list of enctype-salttype pairs for setting the keyof the principal. The quotes are necessary if there are multipleenctype-salttype pairs. This will not function against kadmin daemonsearlier than krb5-1.2. See and for all possible values. -q run in quiet mode. This causes ktadd to display less verboseinformation. principal | -glob principal expression add principal, or all principals matching principal expressionto the keytab. The rules for principal expression are the same asfor the kadmin list_principals (see ) command. Here is a sample session, using configuration files that enable only ‘des-cbc-crc’ encryption. (The line beginning with => is a continuation of the previous line.) kadmin: ktadd host/daffodil.mit.edu@ATHENA.MIT.EDU kadmin: Entry for principal host/daffodil.mit.edu@ATHENA.MIT.EDU with kvno 2, encryption type DES-CBC-CRC added to keytab WRFILE:/etc/krb5.keytab. kadmin: kadmin: ktadd -k /usr/local/var/krb5kdc/kadmind.keytab => kadmin/admin kadmin/changepw kadmin: Entry for principal kadmin/admin@ATHENA.MIT.EDU with kvno 3, encryption type DES-CBC-CRC added to keytab WRFILE:/usr/local/var/krb5kdc/kadmind.keytab. kadmin: Removing Principals from Keytabs To remove a principal from an existing keytab, use the kadmin ktremove command. The syntax is: ktremove [ -k[eytab] keytab ] [ -q ] principal [ kvno | all | old ] The ktremove command takes the following switches: -k[eytab] keytab use keytab as the keytab file. Otherwise, ktremove will usethe default keytab file (/etc/krb5.keytab). -q run in quiet mode. This causes ktremove to display less verboseinformation. principal the principal to remove from the keytab. (Required.) kvno remove all entries for the specified principal whose Key Version Numbersmatch kvno. all remove all entries for the specified principal old remove all entries for the specified principal except those with thehighest kvno. For example: kadmin: ktremove -k /usr/local/var/krb5kdc/kadmind.keytab kadmin/admin kadmin: Entry for principal kadmin/admin with kvno 3 removed from keytab WRFILE:/usr/local/var/krb5kdc/kadmind.keytab. kadmin: Clock Skew In order to prevent intruders from resetting their system clocks in order to continue to use expired tickets, Kerberos V5 is set up to reject ticket requests from any host whose clock is not within the specified maximum clock skew of the KDC (as specified in the kdc.conf file). Similarly, hosts are configured to reject responses from any KDC whose clock is not within the specified maximum clock skew of the host (as specified in the krb5.conf file). The default value for maximum clock skew is 300 seconds, or five minutes. MIT suggests that you add a line to client machines' /etc/rc files to synchronize the machine's clock to your KDC at boot time. On UNIX hosts, assuming you had a kdc called kerberos in your realm, this would be: gettime -s kerberos If the host is not likely to be rebooted frequently, you may also want to set up a cron job that adjusts the time on a regular basis. Getting DNS Information Correct Several aspects of Kerberos rely on name service. In order for Kerberos to provide its high level of security, it is less forgiving of name service problems than some other parts of your network. It is important that your Domain Name System (DNS) entries and your hosts have the correct information. Each host's canonical name must be the fully-qualified host name (including the domain), and each host's IP address must reverse-resolve to the canonical name. Other than the localhost entry, make all entries in each machine's /etc/hosts file in the following form: IP address fully-qualified hostname aliases Here is a sample /etc/hosts file: # this is a comment 127.0.0.1 localhost localhost@mit.edu 10.0.0.6 daffodil.mit.edu trillium wake-robin Additionally, on Solaris machines, you need to be sure the “hosts” entry in the file /etc/nsswitch.conf includes the source “dns” as well as “file”. Finally, each host's keytab file must include a host/key pair for the host's canonical name. You can list the keys in a keytab file by issuing the command klist -k. For example: viola# klist -k Keytab name: /etc/krb5.keytab KVNO Principal ---- ------------------------------------------------------------ 1 host/daffodil.mit.edu@ATHENA.MIT.EDU If you telnet to the host with a fresh credentials cache (ticket file), and then klist, the host's service principal should be host/fully-qualified-hostname@REALM_NAME. Configuring Your Firewall to Work With Kerberos V5 If you need off-site users to be able to get Kerberos tickets in your realm, they must be able to get to your KDC. This requires either that you have a slave KDC outside your firewall, or you configure your firewall to allow UDP requests into at least one of your KDCs, on whichever port the KDC is running. (The default is port 88; other ports may be specified in the KDC's kdc.conf file.) Similarly, if you need off-site users to be able to change their passwords in your realm, they must be able to get to your Kerberos admin server. The default port for the admin server is 749. If your on-site users inside your firewall will need to get to KDCs in other realms, you will also need to configure your firewall to allow outgoing TCP and UDP requests to port 88. Additionally, if they will need to get to any Kerberos V4 KDCs, you may also need to allow TCP and UDP requests to port 750. If your on-site users inside your firewall will need to get to Kerberos admin servers in other realms, you will also need to allow outgoing TCP and UDP requests to port 749. If any of your KDCs are outside your firewall, you will need to allow kprop requests to get through to the remote KDC. Kprop uses the krb5_prop service on port 754 (tcp). If you need your off-site users to have access to machines inside your firewall, you need to allow TCP connections from their off-site hosts on the appropriate ports for the programs they will be using. The following lines from /etc/services show the default port numbers for the Kerberos V5 programs: ftp 21/tcp # Kerberos ftp and telnet use the telnet 23/tcp # default ports kerberos 88/udp kdc # Kerberos V5 KDC kerberos 88/tcp kdc # Kerberos V5 KDC klogin 543/tcp # Kerberos authenticated rlogin kshell 544/tcp cmd # and remote shell kerberos-adm 749/tcp # Kerberos 5 admin/changepw kerberos-adm 749/udp # Kerberos 5 admin/changepw krb5_prop 754/tcp # Kerberos slave propagation eklogin 2105/tcp # Kerberos auth. & encrypted rlogin krb524 4444/tcp # Kerberos 5 to 4 ticket translator By default, Kerberos V5 telnet and ftp use the same ports as the standard telnet and ftp programs, so if you already allow telnet and ftp connections through your firewall, the Kerberos V5 versions will get through as well. If you do not already allow telnet and ftp connections through your firewall, but need your users to be able to use Kerberos V5 telnet and ftp, you can either allow ftp and telnet connections on the standard ports, or switch these programs to non-default port numbers and allow ftp and telnet connections on those ports to get through. Kerberos V5 rlogin uses the klogin service, which by default uses port 543. Encrypted Kerberos V5 rlogin uses the eklogin service, which by default uses port 2105. Kerberos V5 rsh uses the kshell service, which by default uses port 544. However, the server must be able to make a TCP connection from the kshell port to an arbitrary port on the client, so if your users are to be able to use rsh from outside your firewall, the server they connect to must be able to send outgoing packets to arbitrary port numbers. Similarly, if your users need to run rsh from inside your firewall to hosts outside your firewall, the outside server needs to be able to connect to an arbitrary port on the machine inside your firewall. Because Kerberos V5 rcp uses rsh, the same issues apply. If you need to use rsh (or rcp) through your firewall and are concerned with the security implications of allowing connections to arbitrary ports, MIT suggests that you have rules that specifically name these applications and, if possible, list the allowed hosts. The book UNIX System Security, by David Curry, is a good starting point for learning to configure firewalls. Backups of Secure Hosts When you back up a secure host, you should exclude the host's keytab file from the backup. If someone obtained a copy of the keytab from a backup, that person could make any host masquerade as the host whose keytab was compromised. This could be particularly dangerous if the compromised keytab was from one of your KDCs. If the machine has a disk crash and the keytab file is lost, it is easy to generate another keytab file. (See .) If you are unable to exclude particular files from backups, you should ensure that the backups are kept as secure as the host's root password. Backing Up the Kerberos Database As with any file, it is possible that your Kerberos database could become corrupted. If this happens on one of the slave KDCs, you might never notice, since the next automatic propagation of the database would install a fresh copy. However, if it happens to the master KDC, the corrupted database would be propagated to all of the slaves during the next propagation. For this reason, MIT recommends that you back up your Kerberos database regularly. Because the master KDC is continuously dumping the database to a file in order to propagate it to the slave KDCs, it is a simple matter to have a cron job periodically copy the dump file to a secure machine elsewhere on your network. (Of course, it is important to make the host where these backups are stored as secure as your KDCs, and to encrypt its transmission across your network.) Then if your database becomes corrupted, you can load the most recent dump onto the master KDC. (See .) Bug Reporting In any complex software, there will be bugs. If you have successfully built and installed Kerberos V5, please use the krb5-send-pr program to fill out a Problem Report should you encounter any errors in our software. Bug reports that include proposed fixes are especially welcome. If you do include fixes, please send them using either context diffs or unified diffs (using ‘diff -c’ or ‘diff -u’, respectively). Please be careful when using “cut and paste” or other such means to copy a patch into a bug report; depending on the system being used, that can result in converting TAB characters into spaces, which makes applying the patches more difficult. The krb5-send-pr program is installed in the directory /usr/local/sbin. The krb5-send-pr program enters the problem report into our Problem Report Management System (PRMS), which automatically assigns it to the engineer best able to help you with problems in the assigned category. The krb5-send-pr program will try to intelligently fill in as many fields as it can. You need to choose the category, class, severity, and priority of the problem, as well as giving us as much information as you can about its exact nature. The PR category will be one of: krb5-admin krb5-appl krb5-build krb5-clients krb5-doc krb5-kdc krb5-libs krb5-misc pty telnet test Choose the category that best describes the area under which your problem falls. The class can be sw-bug, doc-bug, change-request, or support. The first two are exactly as their names imply. Use change-request when the software is behaving according to specifications, but you want to request changes in some feature or behavior. The support class is intended for more general questions about building or using Kerberos V5. The severity of the problem indicates the problem's impact on the usability of Kerberos V5. If a problem is critical, that means the product, component or concept is completely non-operational, or some essential functionality is missing, and no workaround is known. A serious problem is one in which the product, component or concept is not working properly or significant functionality is missing. Problems that would otherwise be considered critical are rated serious when a workaround is known. A non-critical problem is one that is indeed a problem, but one that is having a minimal effect on your ability to use Kerberos V5. E.g., The product, component or concept is working in general, but lacks features, has irritating behavior, does something wrong, or doesn't match its documentation. The default severity is serious. The priority indicates how urgent this particular problem is in relation to your work. Note that low priority does not imply low importance. A priority of high means a solution is needed as soon as possible. A priority of medium means the problem should be solved no later than the next release. A priority of low means the problem should be solved in a future release, but it is not important to your work how soon this happens. The default priority is medium. Note that a given severity does not necessarily imply a given priority. For example, a non-critical problem might still have a high priority if you are faced with a hard deadline. Conversely, a serious problem might have a low priority if the feature it is disabling is one that you do not need. It is important that you fill in the release field and tell us what changes you have made, if any. A sample filled-out form from a company named “Toasters, Inc.” might look like this: To: krb5-bugs@mit.edu Subject: misspelled "Kerberos" in title of installation guide From: jcb Reply-To: jcb Cc: X-send-pr-version: 3.99 >Submitter-Id: mit >Originator: Jeffrey C. Gilman Bigler >Organization: mit >Confidential: no >Synopsis: Misspelled "Kerberos" in title of installation guide >Severity: non-critical >Priority: low >Category: krb5-doc >Class: doc-bug >Release: 1.0-development >Environment: <machine, os, target, libraries (multiple lines)> System: ULTRIX imbrium 4.2 0 RISC Machine: mips >Description: Misspelled "Kerberos" in title of "Kerboros V5 Installation Guide" >How-To-Repeat: N/A >Fix: Correct the spelling. If the krb5-send-pr program does not work for you, or if you did not get far enough in the process to have an installed and working krb5-send-pr, you can generate your own form, using the above as an example. Appendix Kerberos Error Messages Kerberos V5 Library Error Codes This is the Kerberos v5 library error code table. Protocol error codes are ERROR_TABLE_BASE_krb5 + the protocol error code number; other error codes start at ERROR_TABLE_BASE_krb5 + 128. KRB5KDC_ERR_NONE: No error KRB5KDC_ERR_NAME_EXP: Client's entry in database has expired KRB5KDC_ERR_SERVICE_EXP: Server's entry in database has expired KRB5KDC_ERR_BAD_PVNO: Requested protocol version not supported KRB5KDC_ERR_C_OLD_MAST_KVNO: Client's key is encrypted in an old masterkey KRB5KDC_ERR_S_OLD_MAST_KVNO: Server's key is encrypted in an old masterkey KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN: Client not found in Kerberos database KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN: Server not found in Kerberos database KRB5KDC_ERR_PRINCIPAL_NOT_UNIQUE: Principal has multiple entries inKerberos database KRB5KDC_ERR_NULL_KEY: Client or server has a null key KRB5KDC_ERR_CANNOT_POSTDATE: Ticket is ineligible for postdating KRB5KDC_ERR_NEVER_VALID: Requested effective lifetime is negative ortoo short KRB5KDC_ERR_POLICY: KDC policy rejects request KRB5KDC_ERR_BADOPTION: KDC can't fulfill requested option KRB5KDC_ERR_ETYPE_NOSUPP: KDC has no support for encryption type KRB5KDC_ERR_SUMTYPE_NOSUPP: KDC has no support for checksum type KRB5KDC_ERR_PADATA_TYPE_NOSUPP: KDC has no support for padata type KRB5KDC_ERR_TRTYPE_NOSUPP: KDC has no support for transited type KRB5KDC_ERR_CLIENT_REVOKED: Clients credentials have been revoked KRB5KDC_ERR_SERVICE_REVOKED: Credentials for server have been revoked KRB5KDC_ERR_TGT_REVOKED: TGT has been revoked KRB5KDC_ERR_CLIENT_NOTYET: Client not yet valid - try again later KRB5KDC_ERR_SERVICE_NOTYET: Server not yet valid - try again later KRB5KDC_ERR_KEY_EXP: Password has expired KRB5KDC_ERR_PREAUTH_FAILED: Preauthentication failed KRB5KDC_ERR_PREAUTH_REQUIRED: Additional pre-authentication required KRB5KDC_ERR_SERVER_NOMATCH: Requested server and ticket don't match KRB5PLACEHOLD_27: KRB5 error code 27 KRB5PLACEHOLD_28: KRB5 error code 28 KRB5PLACEHOLD_29: KRB5 error code 29 KRB5PLACEHOLD_30: KRB5 error code 30 KRB5KRB_AP_ERR_BAD_INTEGRITY: Decrypt integrity check failed KRB5KRB_AP_ERR_TKT_EXPIRED: Ticket expired KRB5KRB_AP_ERR_TKT_NYV: Ticket not yet valid KRB5KRB_AP_ERR_REPEAT: Request is a replay KRB5KRB_AP_ERR_NOT_US: The ticket isn't for us KRB5KRB_AP_ERR_BADMATCH: Ticket/authenticator don't match KRB5KRB_AP_ERR_SKEW: Clock skew too great KRB5KRB_AP_ERR_BADADDR: Incorrect net address KRB5KRB_AP_ERR_BADVERSION: Protocol version mismatch KRB5KRB_AP_ERR_MSG_TYPE: Invalid message type KRB5KRB_AP_ERR_MODIFIED: Message stream modified KRB5KRB_AP_ERR_BADORDER: Message out of order KRB5KRB_AP_ERR_ILL_CR_TKT: Illegal cross-realm ticket KRB5KRB_AP_ERR_BADKEYVER: Key version is not available KRB5KRB_AP_ERR_NOKEY: Service key not available KRB5KRB_AP_ERR_MUT_FAIL: Mutual authentication failed KRB5KRB_AP_ERR_BADDIRECTION: Incorrect message direction KRB5KRB_AP_ERR_METHOD: Alternative authentication method required KRB5KRB_AP_ERR_BADSEQ: Incorrect sequence number in message KRB5KRB_AP_ERR_INAPP_CKSUM: Inappropriate type of checksum in message KRB5KRB_AP_PATH_NOT_ACCEPTED: Policy rejects transited path KRB5KRB_ERR_RESPONSE_TOO_BIG: Response too big for UDP, retry with TCP KRB5PLACEHOLD_53: KRB5 error code 53 KRB5PLACEHOLD_54: KRB5 error code 54 KRB5PLACEHOLD_55: KRB5 error code 55 KRB5PLACEHOLD_56: KRB5 error code 56 KRB5PLACEHOLD_57: KRB5 error code 57 KRB5PLACEHOLD_58: KRB5 error code 58 KRB5PLACEHOLD_59: KRB5 error code 59 KRB5KRB_ERR_GENERIC: Generic error (see e-text) KRB5KRB_ERR_FIELD_TOOLONG: Field is too long for this implementation KRB5PLACEHOLD_62: KRB5 error code 62 KRB5PLACEHOLD_63: KRB5 error code 63 KRB5PLACEHOLD_64: KRB5 error code 64 KRB5PLACEHOLD_65: KRB5 error code 65 KRB5PLACEHOLD_66: KRB5 error code 66 KRB5PLACEHOLD_67: KRB5 error code 67 KRB5PLACEHOLD_68: KRB5 error code 68 KRB5PLACEHOLD_69: KRB5 error code 69 KRB5PLACEHOLD_70: KRB5 error code 70 KRB5PLACEHOLD_71: KRB5 error code 71 KRB5PLACEHOLD_72: KRB5 error code 72 KRB5PLACEHOLD_73: KRB5 error code 73 KRB5PLACEHOLD_74: KRB5 error code 74 KRB5PLACEHOLD_75: KRB5 error code 75 KRB5PLACEHOLD_76: KRB5 error code 76 KRB5PLACEHOLD_77: KRB5 error code 77 KRB5PLACEHOLD_78: KRB5 error code 78 KRB5PLACEHOLD_79: KRB5 error code 79 KRB5PLACEHOLD_80: KRB5 error code 80 KRB5PLACEHOLD_81: KRB5 error code 81 KRB5PLACEHOLD_82: KRB5 error code 82 KRB5PLACEHOLD_83: KRB5 error code 83 KRB5PLACEHOLD_84: KRB5 error code 84 KRB5PLACEHOLD_85: KRB5 error code 85 KRB5PLACEHOLD_86: KRB5 error code 86 KRB5PLACEHOLD_87: KRB5 error code 87 KRB5PLACEHOLD_88: KRB5 error code 88 KRB5PLACEHOLD_89: KRB5 error code 89 KRB5PLACEHOLD_90: KRB5 error code 90 KRB5PLACEHOLD_91: KRB5 error code 91 KRB5PLACEHOLD_92: KRB5 error code 92 KRB5PLACEHOLD_93: KRB5 error code 93 KRB5PLACEHOLD_94: KRB5 error code 94 KRB5PLACEHOLD_95: KRB5 error code 95 KRB5PLACEHOLD_96: KRB5 error code 96 KRB5PLACEHOLD_97: KRB5 error code 97 KRB5PLACEHOLD_98: KRB5 error code 98 KRB5PLACEHOLD_99: KRB5 error code 99 KRB5PLACEHOLD_100: KRB5 error code 100 KRB5PLACEHOLD_101: KRB5 error code 101 KRB5PLACEHOLD_102: KRB5 error code 102 KRB5PLACEHOLD_103: KRB5 error code 103 KRB5PLACEHOLD_104: KRB5 error code 104 KRB5PLACEHOLD_105: KRB5 error code 105 KRB5PLACEHOLD_106: KRB5 error code 106 KRB5PLACEHOLD_107: KRB5 error code 107 KRB5PLACEHOLD_108: KRB5 error code 108 KRB5PLACEHOLD_109: KRB5 error code 109 KRB5PLACEHOLD_110: KRB5 error code 110 KRB5PLACEHOLD_111: KRB5 error code 111 KRB5PLACEHOLD_112: KRB5 error code 112 KRB5PLACEHOLD_113: KRB5 error code 113 KRB5PLACEHOLD_114: KRB5 error code 114 KRB5PLACEHOLD_115: KRB5 error code 115 KRB5PLACEHOLD_116: KRB5 error code 116 KRB5PLACEHOLD_117: KRB5 error code 117 KRB5PLACEHOLD_118: KRB5 error code 118 KRB5PLACEHOLD_119: KRB5 error code 119 KRB5PLACEHOLD_120: KRB5 error code 120 KRB5PLACEHOLD_121: KRB5 error code 121 KRB5PLACEHOLD_122: KRB5 error code 122 KRB5PLACEHOLD_123: KRB5 error code 123 KRB5PLACEHOLD_124: KRB5 error code 124 KRB5PLACEHOLD_125: KRB5 error code 125 KRB5PLACEHOLD_126: KRB5 error code 126 KRB5PLACEHOLD_127: KRB5 error code 127 KRB5_ERR_RCSID: (RCS Id string for the krb5 error table) KRB5_LIBOS_BADLOCKFLAG: Invalid flag for file lock mode KRB5_LIBOS_CANTREADPWD: Cannot read password KRB5_LIBOS_BADPWDMATCH: Password mismatch KRB5_LIBOS_PWDINTR: Password read interrupted KRB5_PARSE_ILLCHAR: Illegal character in component name KRB5_PARSE_MALFORMED: Malformed representation of principal KRB5_CONFIG_CANTOPEN: Can't open/find Kerberos configuration file KRB5_CONFIG_BADFORMAT: Improper format of Kerberos configuration file KRB5_CONFIG_NOTENUFSPACE: Insufficient space to return completeinformation KRB5_BADMSGTYPE: Invalid message type specified for encoding KRB5_CC_BADNAME: Credential cache name malformed KRB5_CC_UNKNOWN_TYPE: Unknown credential cache type KRB5_CC_NOTFOUND: Matching credential not found KRB5_CC_END: End of credential cache reached KRB5_NO_TKT_SUPPLIED: Request did not supply a ticket KRB5KRB_AP_WRONG_PRINC: Wrong principal in request KRB5KRB_AP_ERR_TKT_INVALID: Ticket has invalid flag set KRB5_PRINC_NOMATCH: Requested principal and ticket don't match KRB5_KDCREP_MODIFIED: KDC reply did not match expectations KRB5_KDCREP_SKEW: Clock skew too great in KDC reply KRB5_IN_TKT_REALM_MISMATCH: Client/server realm mismatch in initialticket request KRB5_PROG_ETYPE_NOSUPP: Program lacks support for encryption type KRB5_PROG_KEYTYPE_NOSUPP: Program lacks support for key type KRB5_WRONG_ETYPE: Requested encryption type not used in message KRB5_PROG_SUMTYPE_NOSUPP: Program lacks support for checksum type KRB5_REALM_UNKNOWN: Cannot find KDC for requested realm KRB5_SERVICE_UNKNOWN: Kerberos service unknown KRB5_KDC_UNREACH: Cannot contact any KDC for requested realm KRB5_NO_LOCALNAME: No local name found for principal name KRB5_MUTUAL_FAILED: Mutual authentication failed KRB5_RC_TYPE_EXISTS: Replay cache type is already registered KRB5_RC_MALLOC: No more memory to allocate (in replay cache code) KRB5_RC_TYPE_NOTFOUND: Replay cache type is unknown KRB5_RC_UNKNOWN: Generic unknown RC error KRB5_RC_REPLAY: Message is a replay KRB5_RC_IO: Replay I/O operation failed XXX KRB5_RC_NOIO: Replay cache type does not support non-volatile storage KRB5_RC_PARSE: Replay cache name parse/format error KRB5_RC_IO_EOF: End-of-file on replay cache I/O KRB5_RC_IO_MALLOC: No more memory to allocate (in replay cache I/Ocode) KRB5_RC_IO_PERM: Permission denied in replay cache code KRB5_RC_IO_IO: I/O error in replay cache i/o code KRB5_RC_IO_UNKNOWN: Generic unknown RC/IO error KRB5_RC_IO_SPACE: Insufficient system space to store replay information KRB5_TRANS_CANTOPEN: Can't open/find realm translation file KRB5_TRANS_BADFORMAT: Improper format of realm translation file KRB5_LNAME_CANTOPEN: Can't open/find lname translation database KRB5_LNAME_NOTRANS: No translation available for requested principal KRB5_LNAME_BADFORMAT: Improper format of translation database entry KRB5_CRYPTO_INTERNAL: Cryptosystem internal error KRB5_KT_BADNAME: Key table name malformed KRB5_KT_UNKNOWN_TYPE: Unknown Key table type KRB5_KT_NOTFOUND: Key table entry not found KRB5_KT_END: End of key table reached KRB5_KT_NOWRITE: Cannot write to specified key table KRB5_KT_IOERR: Error writing to key table KRB5_NO_TKT_IN_RLM: Cannot find ticket for requested realm KRB5DES_BAD_KEYPAR: DES key has bad parity KRB5DES_WEAK_KEY: DES key is a weak key KRB5_BAD_ENCTYPE: Bad encryption type KRB5_BAD_KEYSIZE: Key size is incompatible with encryption type KRB5_BAD_MSIZE: Message size is incompatible with encryption type KRB5_CC_TYPE_EXISTS: Credentials cache type is already registered. KRB5_KT_TYPE_EXISTS: Key table type is already registered. KRB5_CC_IO: Credentials cache I/O operation failed XXX KRB5_FCC_PERM: Credentials cache file permissions incorrect KRB5_FCC_NOFILE: No credentials cache found KRB5_FCC_INTERNAL: Internal credentials cache error KRB5_CC_WRITE: Error writing to credentials cache KRB5_CC_NOMEM: No more memory to allocate (in credentials cache code) KRB5_CC_FORMAT: Bad format in credentials cache KRB5_INVALID_FLAGS: Invalid KDC option combination (library internalerror) [for dual tgt library calls] KRB5_NO_2ND_TKT: Request missing second ticket [for dual tgt librarycalls] KRB5_NOCREDS_SUPPLIED: No credentials supplied to library routine KRB5_SENDAUTH_BADAUTHVERS: Bad sendauth version was sent KRB5_SENDAUTH_BADAPPLVERS: Bad application version was sent (viasendauth) KRB5_SENDAUTH_BADRESPONSE: Bad response (during sendauth exchange) KRB5_SENDAUTH_REJECTED: Server rejected authentication (during sendauthexchange) KRB5_PREAUTH_BAD_TYPE: Unsupported preauthentication type KRB5_PREAUTH_NO_KEY: Required preauthentication key not supplied KRB5_PREAUTH_FAILED: Generic preauthentication failure KRB5_RCACHE_BADVNO: Unsupported replay cache format version number KRB5_CCACHE_BADVNO: Unsupported credentials cache format version number KRB5_KEYTAB_BADVNO: Unsupported key table format version number KRB5_PROG_ATYPE_NOSUPP: Program lacks support for address type KRB5_RC_REQUIRED: Message replay detection requires rcache parameter KRB5_ERR_BAD_HOSTNAME: Hostname cannot be canonicalized KRB5_ERR_HOST_REALM_UNKNOWN: Cannot determine realm for host KRB5_SNAME_UNSUPP_NAMETYPE: Conversion to service principal undefinedfor name type KRB5KRB_AP_ERR_V4_REPLY: Initial Ticket response appears to be Version4 error KRB5_REALM_CANT_RESOLVE: Cannot resolve KDC for requested realm KRB5_TKT_NOT_FORWARDABLE: Requesting ticket can't get forwardabletickets KRB5_FWD_BAD_PRINCIPAL: Bad principal name while trying to forwardcredentials KRB5_GET_IN_TKT_LOOP: Looping detected inside krb5_get_in_tkt KRB5_CONFIG_NODEFREALM: Configuration file does not specify default realm KRB5_SAM_UNSUPPORTED: Bad SAM flags in obtain_sam_padata KRB5_KT_NAME_TOOLONG: Keytab name too long KRB5_KT_KVNONOTFOUND: Key version number for principal in key table is incorrect KRB5_APPL_EXPIRED: This application has expired KRB5_LIB_EXPIRED: This Krb5 library has expired KRB5_CHPW_PWDNULL: New password cannot be zero length KRB5_CHPW_FAIL: Password change failed KRB5_KT_FORMAT: Bad format in keytab KRB5_NOPERM_ETYPE: Encryption type not permitted KRB5_CONFIG_ETYPE_NOSUPP: No supported encryption types (config file error?) KRB5_OBSOLETE_FN: Program called an obsolete, deleted function KRB5_EAI_FAIL: unknown getaddrinfo failure KRB5_EAI_NODATA: no data available for host/domain name KRB5_EAI_NONAME: host/domain name not found KRB5_EAI_SERVICE: service name unknown KRB5_ERR_NUMERIC_REALM: Cannot determine realm for numeric host address Kerberos V5 Database Library Error Codes This is the Kerberos v5 database library error code table. KRB5_KDB_RCSID: (RCS Id string for the kdb error table) KRB5_KDB_INUSE: Entry already exists in database KRB5_KDB_UK_SERROR: Database store error KRB5_KDB_UK_RERROR: Database read error KRB5_KDB_UNAUTH: Insufficient access to perform requested operation KRB5_KDB_NOENTRY: No such entry in the database KRB5_KDB_ILL_WILDCARD: Illegal use of wildcard KRB5_KDB_DB_INUSE: Database is locked or in use–try again later KRB5_KDB_DB_CHANGED: Database was modified during read KRB5_KDB_TRUNCATED_RECORD: Database record is incomplete or corrupted KRB5_KDB_RECURSIVELOCK: Attempt to lock database twice KRB5_KDB_NOTLOCKED: Attempt to unlock database when not locked KRB5_KDB_BADLOCKMODE: Invalid kdb lock mode KRB5_KDB_DBNOTINITED: Database has not been initialized KRB5_KDB_DBINITED: Database has already been initialized KRB5_KDB_ILLDIRECTION: Bad direction for converting keys KRB5_KDB_NOMASTERKEY: Cannot find master key record in database KRB5_KDB_BADMASTERKEY: Master key does not match database KRB5_KDB_INVALIDKEYSIZE: Key size in database is invalid KRB5_KDB_CANTREAD_STORED: Cannot find/read stored master key KRB5_KDB_BADSTORED_MKEY: Stored master key is corrupted KRB5_KDB_CANTLOCK_DB: Insufficient access to lock database KRB5_KDB_DB_CORRUPT: Database format error KRB5_KDB_BAD_VERSION: Unsupported version in database entry KRB5_KDB_BAD_SALTTYPE: Unsupported salt type KRB5_KDB_BAD_ENCTYPE: Unsupported encryption type KRB5_KDB_BAD_CREATEFLAGS: Bad database creation flags KRB5_KDB_NO_PERMITTED_KEY: No matching key in entry having a permitted enc type KRB5_KDB_NO_MATCHING_KEY: No matching key in entry KRB5_KDB_SERVER_INTERNAL_ERR: Server error KRB5_KDB_ACCESS_ERROR: Unable to access Kerberos database KRB5_KDB_INTERNAL_ERROR:Kerberos database internal error KRB5_KDB_CONSTRAINT_VIOLATION:Kerberos database constraints violated Kerberos V5 Magic Numbers Error Codes This is the Kerberos v5 magic numbers error code table. KV5M_NONE: Kerberos V5 magic number table KV5M_PRINCIPAL: Bad magic number for krb5_principal structure KV5M_DATA: Bad magic number for krb5_data structure KV5M_KEYBLOCK: Bad magic number for krb5_keyblock structure KV5M_CHECKSUM: Bad magic number for krb5_checksum structure KV5M_ENCRYPT_BLOCK: Bad magic number for krb5_encrypt_block structure KV5M_ENC_DATA: Bad magic number for krb5_enc_data structure KV5M_CRYPTOSYSTEM_ENTRY: Bad magic number for krb5_cryptosystem_entrystructure KV5M_CS_TABLE_ENTRY: Bad magic number for krb5_cs_table_entry structure KV5M_CHECKSUM_ENTRY: Bad magic number for krb5_checksum_entry structure KV5M_AUTHDATA: Bad magic number for krb5_authdata structure KV5M_TRANSITED: Bad magic number for krb5_transited structure KV5M_ENC_TKT_PART: Bad magic number for krb5_enc_tkt_part structure KV5M_TICKET: Bad magic number for krb5_ticket structure KV5M_AUTHENTICATOR: Bad magic number for krb5_authenticator structure KV5M_TKT_AUTHENT: Bad magic number for krb5_tkt_authent structure KV5M_CREDS: Bad magic number for krb5_creds structure KV5M_LAST_REQ_ENTRY: Bad magic number for krb5_last_req_entry structure KV5M_PA_DATA: Bad magic number for krb5_pa_data structure KV5M_KDC_REQ: Bad magic number for krb5_kdc_req structure KV5M_ENC_KDC_REP_PART: Bad magic number for krb5_enc_kdc_rep_part structure KV5M_KDC_REP: Bad magic number for krb5_kdc_rep structure KV5M_ERROR: Bad magic number for krb5_error structure KV5M_AP_REQ: Bad magic number for krb5_ap_req structure KV5M_AP_REP: Bad magic number for krb5_ap_rep structure KV5M_AP_REP_ENC_PART: Bad magic number for krb5_ap_rep_enc_part structure KV5M_RESPONSE: Bad magic number for krb5_response structure KV5M_SAFE: Bad magic number for krb5_safe structure KV5M_PRIV: Bad magic number for krb5_priv structure KV5M_PRIV_ENC_PART: Bad magic number for krb5_priv_enc_part structure KV5M_CRED: Bad magic number for krb5_cred structure KV5M_CRED_INFO: Bad magic number for krb5_cred_info structure KV5M_CRED_ENC_PART: Bad magic number for krb5_cred_enc_part structure KV5M_PWD_DATA: Bad magic number for krb5_pwd_data structure KV5M_ADDRESS: Bad magic number for krb5_address structure KV5M_KEYTAB_ENTRY: Bad magic number for krb5_keytab_entry structure KV5M_CONTEXT: Bad magic number for krb5_context structure KV5M_OS_CONTEXT: Bad magic number for krb5_os_context structure KV5M_ALT_METHOD: Bad magic number for krb5_alt_method structure KV5M_ETYPE_INFO_ENTRY: Bad magic number for krb5_etype_info_entry structure KV5M_DB_CONTEXT: Bad magic number for krb5_db_context structure KV5M_AUTH_CONTEXT: Bad magic number for krb5_auth_context structure KV5M_KEYTAB: Bad magic number for krb5_keytab structure KV5M_RCACHE: Bad magic number for krb5_rcache structure KV5M_CCACHE: Bad magic number for krb5_ccache structure KV5M_PREAUTH_OPS: Bad magic number for krb5_preauth_ops KV5M_SAM_CHALLENGE: Bad magic number for krb5_sam_challenge KV5M_SAM_KEY: Bad magic number for krb5_sam_key KV5M_ENC_SAM_RESPONSE_ENC: Bad magic number for krb5_enc_sam_response_enc KV5M_SAM_RESPONSE: Bad magic number for krb5_sam_response KV5M_PREDICTED_SAM_RESPONSE: Bad magic number forkrb5_predicted_sam_response KV5M_PASSWD_PHRASE_ELEMENT: Bad magic number for passwd_phrase_element KV5M_GSS_OID: Bad magic number for GSSAPI OID KV5M_GSS_QUEUE: Bad magic number for GSSAPI QUEUE ASN.1 Error Codes ASN1_BAD_TIMEFORMAT: ASN.1 failed call to system time library ASN1_MISSING_FIELD: ASN.1 structure is missing a required field ASN1_MISPLACED_FIELD: ASN.1 unexpected field number ASN1_TYPE_MISMATCH: ASN.1 type numbers are inconsistent ASN1_OVERFLOW: ASN.1 value too large ASN1_OVERRUN: ASN.1 encoding ended unexpectedly ASN1_BAD_ID: ASN.1 identifier doesn't match expected value ASN1_BAD_LENGTH: ASN.1 length doesn't match expected value ASN1_BAD_FORMAT: ASN.1 badly-formatted encoding ASN1_PARSE_ERROR: ASN.1 parse error ASN1_BAD_GMTIME: ASN.1 bad return from gmtime ASN1_MISMATCH_INDEF: ASN.1 non-constructed indefinite encoding ASN1_MISSING_EOC: ASN.1 missing expected EOC GSSAPI Error Codes Generic GSSAPI Errors: G_BAD_SERVICE_NAME: No in SERVICE-NAME name string G_BAD_STRING_UID: STRING-UID-NAME contains nondigits G_NOUSER: UID does not resolve to username G_VALIDATE_FAILED: Validation error G_BUFFER_ALLOC: Couldn't allocate gss_buffer_t data G_BAD_MSG_CTX: Message context invalid G_WRONG_SIZE: Buffer is the wrong size G_BAD_USAGE: Credential usage type is unknown G_UNKNOWN_QOP: Unknown quality of protection specified G_BAD_HOSTNAME: Hostname in SERVICE-NAME string could not becanonicalized G_WRONG_MECH: Mechanism is incorrect G_BAD_TOK_HEADER: Token header is malformed or corrupt G_BAD_DIRECTION: Packet was replayed in wrong direction G_TOK_TRUNC: Token is missing data G_REFLECT: Token was reflected G_WRONG_TOKID: Received token ID does not match expected token ID Kerberos 5 GSSAPI Errors: KG_CCACHE_NOMATCH: Principal in credential cache does not match desiredname KG_KEYTAB_NOMATCH: No principal in keytab matches desired name KG_TGT_MISSING: Credential cache has no TGT KG_NO_SUBKEY: Authenticator has no subkey KG_CONTEXT_ESTABLISHED: Context is already fully established KG_BAD_SIGN_TYPE: Unknown signature type in token KG_BAD_LENGTH: Invalid field length in token KG_CTX_INCOMPLETE: Attempt to use incomplete security context KG_CONTEXT: Bad magic number for krb5_gss_ctx_id_t KG_CRED: Bad magic number for krb5_gss_cred_id_t KG_ENC_DESC: Bad magic number for krb5_gss_enc_desc KG_BAD_SEQ: Sequence number in token is corrupt KG_EMPTY_CCACHE: Credential cache is empty KG_NO_CTYPES: Acceptor and Initiator share no checksum types kadmin Time Zones This is a complete listing of the time zones recognized by the kadmin command. gmt Greenwich Mean Time ut, utc Universal Time (Coordinated). wet Western European Time. (Same as GMT.) bst British Summer Time. (1 hour ahead of GMT.) wat West Africa Time. (1 hour behind GMT.) at Azores Time. (2 hours behind GMT.) bst Brazil Standard Time. (3 hours behind GMT.) Note that the abbreviationBST also stands for British Summer Time. gst Greenland Standard Time. (3 hours behind GMT.) Note that theabbreviation GST also stands for Guam Standard Time. nft Newfoundland Time. (3.5 hours behind GMT.) nst Newfoundland Standard Time. (3.5 hours behind GMT.) ndt Newfoundland Daylight Time. (2.5 hours behind GMT.) ast Atlantic Standard Time. (4 hours behind GMT.) adt Atlantic Daylight Time. (3 hours behind GMT.) est Eastern Standard Time. (5 hours behind GMT.) edt Eastern Daylight Time. (4 hours behind GMT.) cst Central Standard Time. (6 hours behind GMT.) cdt Central Daylight Time. (5 hours behind GMT.) mst Mountain Standard Time. (7 hours behind GMT.) mdt Mountain Daylight Time. (6 hours behind GMT.) pst Pacific Standard Time. (8 hours behind GMT.) pdt Pacific Daylight Time. (7 hours behind GMT.) yst Yukon Standard Time. (9 hours behind GMT.) ydt Yukon Daylight Time. (8 hours behind GMT.) hst Hawaii Standard Time. (10 hours behind GMT.) hdt Hawaii Daylight Time. (9 hours behind GMT.) cat Central Alaska Time. (10 hours behind GMT.) ahst Alaska-Hawaii Standard Time. (10 hours behind GMT.) nt Nome Time. (11 hours behind GMT.) idlw International Date Line West Time. (12 hours behind GMT.) cet Central European Time. (1 hour ahead of GMT.) met Middle European Time. (1 hour ahead of GMT.) mewt Middle European Winter Time. (1 hour ahead of GMT.) mest Middle European Summer Time. (2 hours ahead of GMT.) swt Swedish Winter Time. (1 hour ahead of GMT.) sst Swedish Summer Time. (1 hours ahead of GMT.) fwt French Winter Time. (1 hour ahead of GMT.) fst French Summer Time. (2 hours ahead of GMT.) eet Eastern Europe Time; Russia Zone 1. (2 hours ahead of GMT.) bt Baghdad Time; Russia Zone 2. (3 hours ahead of GMT.) it Iran Time. (3.5 hours ahead of GMT.) zp4 Russia Zone 3. (4 hours ahead of GMT.) zp5 Russia Zone 4. (5 hours ahead of GMT.) ist Indian Standard Time. (5.5 hours ahead of GMT.) zp6 Russia Zone 5. (6 hours ahead of GMT.) nst North Sumatra Time. (6.5 hours ahead of GMT.) Note that theabbreviation NST is also used for Newfoundland Stanard Time. sst South Sumatra Time; Russia Zone 6. (7 hours ahead of GMT.) Note thatSST is also Swedish Summer Time. wast West Australian Standard Time. (7 hours ahead of GMT.) wadt West Australian Daylight Time. (8 hours ahead of GMT.) jt Java Time. (7.5 hours ahead of GMT.) cct China Coast Time; Russia Zone 7. (8 hours ahead of GMT.) jst Japan Standard time; Russia Zone 8. (9 hours ahead of GMT.) kst Korean Standard Time. (9 hours ahead of GMT.) cast Central Australian Standard Time. (9.5 hours ahead of GMT.) cadt Central Australian Daylight Time. (10.5 hours ahead of GMT.) east Eastern Australian Standard Time. (10 hours ahead of GMT.) eadt Eastern Australian Daylight Time. (11 hours ahead of GMT.) gst Guam Standard Time; Russia Zone 9. (10 hours ahead of GMT.) kdt Korean Daylight Time. (10 hours ahead of GMT.) nzt New Zealand Time. (12 hours ahead of GMT.) nzst New Zealand Standard Time. (12 hours ahead of GMT.) nzdt New Zealand Daylight Time. (13 hours ahead of GMT.) idle International Date Line East. (12 hours ahead of GMT.)