{"Entry":{"collection":"auth","key":"gss","name":"gss","aliases":[],"metadata":{"aliases":[],"category":"Authentication and access control","content_hash":"c005cdef9009c12c405513d4e8fe56d43322f357f5aba2bbe58cc441f5ada3b4","imported_at":"2026-09-30T00:40:33.278921+08:00","name":"gss","name_zh":"","slug":"gss","summary":"Use GSSAPI to authenticate the user. This is only available for TCP/IP connections. See Section 20.6 for details. It can be used in conjunction with GSSAPI encryption."}},"Definition":{"Collection":"auth","Key":"gss","SourceDatabase":"center","Version":"18","SourceTable":"authentication_method","SourceKey":"gss","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","Facts":{"aliases":[],"attributes":{"configuration":"pg_hba.conf","inventory":"User-visible source authentication method","method":"gss"},"comparison_data":{"documented_option_names":["include_realm","krb_realm","map"],"method":"gss"},"comparison_hash":"c58b84e18bba9d75d595bab34b326eb6a8580a80636f79642c4af8843e7123cf","description":["Use GSSAPI to authenticate the user. This is only available for TCP/IP connections. See Section 20.6 for details. It can be used in conjunction with GSSAPI encryption."],"facts":[{"label":"Method","value":"gss"},{"label":"Configuration","value":"pg_hba.conf"},{"label":"Inventory","value":"User-visible source authentication method"}],"manual_html":"\u003cdiv class=\"sect1\" id=\"GSSAPI-AUTH\"\u003e\n\u003cdiv class=\"titlepage\"\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003ch2 class=\"title\"\u003e20.6. GSSAPI Authentication \u003c/h2\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e is an industry-standard protocol for secure authentication defined in \u003ca class=\"ulink\" href=\"https://datatracker.ietf.org/doc/html/rfc2743\"\u003eRFC 2743\u003c/a\u003e. \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e supports \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e for authentication, communications encryption, or both. \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e provides automatic authentication (single sign-on) for systems that support it. The authentication itself is secure. If \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e encryption or SSL encryption is used, the data sent along the database connection will be encrypted; otherwise, it will not.\u003c/p\u003e\n\u003cp\u003eGSSAPI support has to be enabled when \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e is built; see \u003ca class=\"xref\" href=\"/docs/18/installation.html\" title=\"Chapter 17. Installation from Source Code\"\u003eChapter 17\u003c/a\u003e for more information.\u003c/p\u003e\n\u003cp\u003eWhen \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e uses \u003cspan class=\"productname\"\u003eKerberos\u003c/span\u003e, it uses a standard service principal (authentication identity) name in the format \u003ccode class=\"literal\"\u003e\u003cem class=\"replaceable\"\u003e\u003ccode\u003eservicename\u003c/code\u003e\u003c/em\u003e/\u003cem class=\"replaceable\"\u003e\u003ccode\u003ehostname\u003c/code\u003e\u003c/em\u003e@\u003cem class=\"replaceable\"\u003e\u003ccode\u003erealm\u003c/code\u003e\u003c/em\u003e\u003c/code\u003e. The principal name used by a particular installation is not encoded in the \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e server in any way; rather it is specified in the \u003cem class=\"firstterm\"\u003ekeytab\u003c/em\u003e file that the server reads to determine its identity. If multiple principals are listed in the keytab file, the server will accept any one of them. The server's realm name is the preferred realm specified in the Kerberos configuration file(s) accessible to the server.\u003c/p\u003e\n\u003cp\u003eWhen connecting, the client must know the principal name of the server it intends to connect to. The \u003cem class=\"replaceable\"\u003e\u003ccode\u003eservicename\u003c/code\u003e\u003c/em\u003e part of the principal is ordinarily \u003ccode class=\"literal\"\u003epostgres\u003c/code\u003e, but another value can be selected via \u003cspan class=\"application\"\u003elibpq\u003c/span\u003e's \u003ca class=\"xref\" href=\"/docs/18/libpq-connect.html#LIBPQ-CONNECT-KRBSRVNAME\"\u003ekrbsrvname\u003c/a\u003e connection parameter. The \u003cem class=\"replaceable\"\u003e\u003ccode\u003ehostname\u003c/code\u003e\u003c/em\u003e part is the fully qualified host name that \u003cspan class=\"application\"\u003elibpq\u003c/span\u003e is told to connect to. The realm name is the preferred realm specified in the Kerberos configuration file(s) accessible to the client.\u003c/p\u003e\n\u003cp\u003eThe client will also have a principal name for its own identity (and it must have a valid ticket for this principal). To use \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e for authentication, the client principal must be associated with a \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e database user name. The \u003ccode class=\"filename\"\u003epg_ident.conf\u003c/code\u003e configuration file can be used to map principals to user names; for example, \u003ccode class=\"literal\"\u003epgusername@realm\u003c/code\u003e could be mapped to just \u003ccode class=\"literal\"\u003epgusername\u003c/code\u003e. Alternatively, you can use the full \u003ccode class=\"literal\"\u003eusername@realm\u003c/code\u003e principal as the role name in \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e without any mapping.\u003c/p\u003e\n\u003cp\u003e\u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e also supports mapping client principals to user names by just stripping the realm from the principal. This method is supported for backwards compatibility and is strongly discouraged as it is then impossible to distinguish different users with the same user name but coming from different realms. To enable this, set \u003ccode class=\"literal\"\u003einclude_realm\u003c/code\u003e to 0. For simple single-realm installations, doing that combined with setting the \u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e parameter (which checks that the principal's realm matches exactly what is in the \u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e parameter) is still secure; but this is a less capable approach compared to specifying an explicit mapping in \u003ccode class=\"filename\"\u003epg_ident.conf\u003c/code\u003e.\u003c/p\u003e\n\u003cp\u003eThe location of the server's keytab file is specified by the \u003ca class=\"xref\" href=\"/docs/18/runtime-config-connection.html#GUC-KRB-SERVER-KEYFILE\"\u003ekrb_server_keyfile\u003c/a\u003e configuration parameter. For security reasons, it is recommended to use a separate keytab just for the \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e server rather than allowing the server to read the system keytab file. Make sure that your server keytab file is readable (and preferably only readable, not writable) by the \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e server account. (See also \u003ca class=\"xref\" href=\"/docs/18/postgres-user.html\" title=\"18.1. The PostgreSQL User Account\"\u003eSection 18.1\u003c/a\u003e.)\u003c/p\u003e\n\u003cp\u003eThe keytab file is generated using the Kerberos software; see the Kerberos documentation for details. The following example shows doing this using the \u003cspan class=\"application\"\u003ekadmin\u003c/span\u003e tool of MIT Kerberos:\u003c/p\u003e\n\u003cpre class=\"screen\"\u003e\u003ccode class=\"prompt\"\u003ekadmin% \u003c/code\u003e\u003cstrong class=\"userinput\"\u003e\u003ccode\u003eaddprinc -randkey postgres/server.my.domain.org\u003c/code\u003e\u003c/strong\u003e\n\u003ccode class=\"prompt\"\u003ekadmin% \u003c/code\u003e\u003cstrong class=\"userinput\"\u003e\u003ccode\u003ektadd -k krb5.keytab postgres/server.my.domain.org\u003c/code\u003e\u003c/strong\u003e\n\u003c/pre\u003e\n\u003cp\u003eThe following authentication options are supported for the \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e authentication method:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003einclude_realm\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIf set to 0, the realm name from the authenticated user principal is stripped off before being passed through the user name mapping (\u003ca class=\"xref\" href=\"/docs/18/auth-username-maps.html\" title=\"20.2. User Name Maps\"\u003eSection 20.2\u003c/a\u003e). This is discouraged and is primarily available for backwards compatibility, as it is not secure in multi-realm environments unless \u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e is also used. It is recommended to leave \u003ccode class=\"literal\"\u003einclude_realm\u003c/code\u003e set to the default (1) and to provide an explicit mapping in \u003ccode class=\"filename\"\u003epg_ident.conf\u003c/code\u003e to convert principal names to \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e user names.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003emap\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eAllows mapping from client principals to database user names. See \u003ca class=\"xref\" href=\"/docs/18/auth-username-maps.html\" title=\"20.2. User Name Maps\"\u003eSection 20.2\u003c/a\u003e for details. For a GSSAPI/Kerberos principal, such as \u003ccode class=\"literal\"\u003eusername@EXAMPLE.COM\u003c/code\u003e (or, less commonly, \u003ccode class=\"literal\"\u003eusername/hostbased@EXAMPLE.COM\u003c/code\u003e), the user name used for mapping is \u003ccode class=\"literal\"\u003eusername@EXAMPLE.COM\u003c/code\u003e (or \u003ccode class=\"literal\"\u003eusername/hostbased@EXAMPLE.COM\u003c/code\u003e, respectively), unless \u003ccode class=\"literal\"\u003einclude_realm\u003c/code\u003e has been set to 0, in which case \u003ccode class=\"literal\"\u003eusername\u003c/code\u003e (or \u003ccode class=\"literal\"\u003eusername/hostbased\u003c/code\u003e) is what is seen as the system user name when mapping.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSets the realm to match user principal names against. If this parameter is set, only users of that realm will be accepted. If it is not set, users of any realm can connect, subject to whatever user name mapping is done.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eIn addition to these settings, which can be different for different \u003ccode class=\"filename\"\u003epg_hba.conf\u003c/code\u003e entries, there is the server-wide \u003ca class=\"xref\" href=\"/docs/18/runtime-config-connection.html#GUC-KRB-CASEINS-USERS\"\u003ekrb_caseins_users\u003c/a\u003e configuration parameter. If that is set to true, client principals are matched to user map entries case-insensitively. \u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e, if set, is also matched case-insensitively.\u003c/p\u003e\n\u003c/div\u003e","manual_path":"/docs/18/gssapi-auth.html","related":[],"release":{"catalog_fingerprint":"65c93d6048ef30e61023a84f9680fa6a92b1c383b7eb226741170077eb078502","channel":"stable","label":"18.6","major":"18","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","source_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sections":[],"signature":"","sources":[{"label":"Matching PostgreSQL source archive","sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2"},{"label":"PostgreSQL 18 English manual","path":"gssapi-auth.html","sha256":"00da5d918d0d4f101749a389bcef7ae273436d43ddf22dcb5d38d2ec1d7c8735","url":"/docs/18/gssapi-auth.html"},{"label":"PostgreSQL 18 English manual","path":"auth-pg-hba-conf.html","sha256":"6340d4abea2e0a3482afc31bcd1599a0fa10dc28a6f1e05d79ba831e2dd0b4c9","url":"/docs/18/auth-pg-hba-conf.html"}],"tables":[{"columns":[{"key":"name","label":"Option or term"},{"key":"description","label":"Meaning"}],"key":"method-options","rows":[{"description":"If set to 0, the realm name from the authenticated user principal is stripped off before being passed through the user name mapping ( Section 20.2 ). This is discouraged and is primarily available for backwards compatibility, as it is not secure in multi-realm environments unless krb_realm is also used. It is recommended to leave include_realm set to the default (1) and to provide an explicit mapping in pg_ident.conf to convert principal names to PostgreSQL user names.","name":"include_realm"},{"description":"Allows mapping from client principals to database user names. See Section 20.2 for details. For a GSSAPI/Kerberos principal, such as username@EXAMPLE.COM (or, less commonly, username/hostbased@EXAMPLE.COM ), the user name used for mapping is username@EXAMPLE.COM (or username/hostbased@EXAMPLE.COM , respectively), unless include_realm has been set to 0, in which case username (or username/hostbased ) is what is seen as the system user name when mapping.","name":"map"},{"description":"Sets the realm to match user principal names against. If this parameter is set, only users of that realm will be accepted. If it is not set, users of any realm can connect, subject to whatever user name mapping is done.","name":"krb_realm"}],"title":"Documented method options and alternatives"}]},"ManualEvidence":{"manual_path":"/docs/18/gssapi-auth.html","release":{"catalog_fingerprint":"65c93d6048ef30e61023a84f9680fa6a92b1c383b7eb226741170077eb078502","channel":"stable","label":"18.6","major":"18","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","source_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sources":[{"label":"Matching PostgreSQL source archive","sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2"},{"label":"PostgreSQL 18 English manual","path":"gssapi-auth.html","sha256":"00da5d918d0d4f101749a389bcef7ae273436d43ddf22dcb5d38d2ec1d7c8735","url":"/docs/18/gssapi-auth.html"},{"label":"PostgreSQL 18 English manual","path":"auth-pg-hba-conf.html","sha256":"6340d4abea2e0a3482afc31bcd1599a0fa10dc28a6f1e05d79ba831e2dd0b4c9","url":"/docs/18/auth-pg-hba-conf.html"}]},"MeasuredEvidence":{}},"Text":{"Collection":"auth","Key":"gss","SourceDatabase":"center","Version":"18","Locale":"en","Title":"gss","Summary":"Use GSSAPI to authenticate the user. This is only available for TCP/IP connections. See Section 20.6 for details. It can be used in conjunction with GSSAPI encryption.","BodyHTML":"\u003cdiv id=\"GSSAPI-AUTH\"\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003ch2\u003e20.6. GSSAPI Authentication \u003c/h2\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cspan\u003eGSSAPI\u003c/span\u003e is an industry-standard protocol for secure authentication defined in \u003ca href=\"https://datatracker.ietf.org/doc/html/rfc2743\" rel=\"nofollow\"\u003eRFC 2743\u003c/a\u003e. \u003cspan\u003ePostgreSQL\u003c/span\u003e supports \u003cspan\u003eGSSAPI\u003c/span\u003e for authentication, communications encryption, or both. \u003cspan\u003eGSSAPI\u003c/span\u003e provides automatic authentication (single sign-on) for systems that support it. The authentication itself is secure. If \u003cspan\u003eGSSAPI\u003c/span\u003e encryption or SSL encryption is used, the data sent along the database connection will be encrypted; otherwise, it will not.\u003c/p\u003e\n\u003cp\u003eGSSAPI support has to be enabled when \u003cspan\u003ePostgreSQL\u003c/span\u003e is built; see \u003ca href=\"/docs/18/installation.html\" rel=\"nofollow\"\u003eChapter 17\u003c/a\u003e for more information.\u003c/p\u003e\n\u003cp\u003eWhen \u003cspan\u003eGSSAPI\u003c/span\u003e uses \u003cspan\u003eKerberos\u003c/span\u003e, it uses a standard service principal (authentication identity) name in the format \u003ccode\u003e\u003cem\u003e\u003ccode\u003eservicename\u003c/code\u003e\u003c/em\u003e/\u003cem\u003e\u003ccode\u003ehostname\u003c/code\u003e\u003c/em\u003e@\u003cem\u003e\u003ccode\u003erealm\u003c/code\u003e\u003c/em\u003e\u003c/code\u003e. The principal name used by a particular installation is not encoded in the \u003cspan\u003ePostgreSQL\u003c/span\u003e server in any way; rather it is specified in the \u003cem\u003ekeytab\u003c/em\u003e file that the server reads to determine its identity. If multiple principals are listed in the keytab file, the server will accept any one of them. The server\u0026#39;s realm name is the preferred realm specified in the Kerberos configuration file(s) accessible to the server.\u003c/p\u003e\n\u003cp\u003eWhen connecting, the client must know the principal name of the server it intends to connect to. The \u003cem\u003e\u003ccode\u003eservicename\u003c/code\u003e\u003c/em\u003e part of the principal is ordinarily \u003ccode\u003epostgres\u003c/code\u003e, but another value can be selected via \u003cspan\u003elibpq\u003c/span\u003e\u0026#39;s \u003ca href=\"/docs/18/libpq-connect.html#LIBPQ-CONNECT-KRBSRVNAME\" rel=\"nofollow\"\u003ekrbsrvname\u003c/a\u003e connection parameter. The \u003cem\u003e\u003ccode\u003ehostname\u003c/code\u003e\u003c/em\u003e part is the fully qualified host name that \u003cspan\u003elibpq\u003c/span\u003e is told to connect to. The realm name is the preferred realm specified in the Kerberos configuration file(s) accessible to the client.\u003c/p\u003e\n\u003cp\u003eThe client will also have a principal name for its own identity (and it must have a valid ticket for this principal). To use \u003cspan\u003eGSSAPI\u003c/span\u003e for authentication, the client principal must be associated with a \u003cspan\u003ePostgreSQL\u003c/span\u003e database user name. The \u003ccode\u003epg_ident.conf\u003c/code\u003e configuration file can be used to map principals to user names; for example, \u003ccode\u003epgusername@realm\u003c/code\u003e could be mapped to just \u003ccode\u003epgusername\u003c/code\u003e. Alternatively, you can use the full \u003ccode\u003eusername@realm\u003c/code\u003e principal as the role name in \u003cspan\u003ePostgreSQL\u003c/span\u003e without any mapping.\u003c/p\u003e\n\u003cp\u003e\u003cspan\u003ePostgreSQL\u003c/span\u003e also supports mapping client principals to user names by just stripping the realm from the principal. This method is supported for backwards compatibility and is strongly discouraged as it is then impossible to distinguish different users with the same user name but coming from different realms. To enable this, set \u003ccode\u003einclude_realm\u003c/code\u003e to 0. For simple single-realm installations, doing that combined with setting the \u003ccode\u003ekrb_realm\u003c/code\u003e parameter (which checks that the principal\u0026#39;s realm matches exactly what is in the \u003ccode\u003ekrb_realm\u003c/code\u003e parameter) is still secure; but this is a less capable approach compared to specifying an explicit mapping in \u003ccode\u003epg_ident.conf\u003c/code\u003e.\u003c/p\u003e\n\u003cp\u003eThe location of the server\u0026#39;s keytab file is specified by the \u003ca href=\"/docs/18/runtime-config-connection.html#GUC-KRB-SERVER-KEYFILE\" rel=\"nofollow\"\u003ekrb_server_keyfile\u003c/a\u003e configuration parameter. For security reasons, it is recommended to use a separate keytab just for the \u003cspan\u003ePostgreSQL\u003c/span\u003e server rather than allowing the server to read the system keytab file. Make sure that your server keytab file is readable (and preferably only readable, not writable) by the \u003cspan\u003ePostgreSQL\u003c/span\u003e server account. (See also \u003ca href=\"/docs/18/postgres-user.html\" rel=\"nofollow\"\u003eSection 18.1\u003c/a\u003e.)\u003c/p\u003e\n\u003cp\u003eThe keytab file is generated using the Kerberos software; see the Kerberos documentation for details. The following example shows doing this using the \u003cspan\u003ekadmin\u003c/span\u003e tool of MIT Kerberos:\u003c/p\u003e\n\u003cpre\u003e\u003ccode\u003ekadmin% \u003c/code\u003e\u003cstrong\u003e\u003ccode\u003eaddprinc -randkey postgres/server.my.domain.org\u003c/code\u003e\u003c/strong\u003e\n\u003ccode\u003ekadmin% \u003c/code\u003e\u003cstrong\u003e\u003ccode\u003ektadd -k krb5.keytab postgres/server.my.domain.org\u003c/code\u003e\u003c/strong\u003e\n\u003c/pre\u003e\n\u003cp\u003eThe following authentication options are supported for the \u003cspan\u003eGSSAPI\u003c/span\u003e authentication method:\u003c/p\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003e\u003ccode\u003einclude_realm\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIf set to 0, the realm name from the authenticated user principal is stripped off before being passed through the user name mapping (\u003ca href=\"/docs/18/auth-username-maps.html\" rel=\"nofollow\"\u003eSection 20.2\u003c/a\u003e). This is discouraged and is primarily available for backwards compatibility, as it is not secure in multi-realm environments unless \u003ccode\u003ekrb_realm\u003c/code\u003e is also used. It is recommended to leave \u003ccode\u003einclude_realm\u003c/code\u003e set to the default (1) and to provide an explicit mapping in \u003ccode\u003epg_ident.conf\u003c/code\u003e to convert principal names to \u003cspan\u003ePostgreSQL\u003c/span\u003e user names.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003e\u003ccode\u003emap\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eAllows mapping from client principals to database user names. See \u003ca href=\"/docs/18/auth-username-maps.html\" rel=\"nofollow\"\u003eSection 20.2\u003c/a\u003e for details. For a GSSAPI/Kerberos principal, such as \u003ccode\u003eusername@EXAMPLE.COM\u003c/code\u003e (or, less commonly, \u003ccode\u003eusername/hostbased@EXAMPLE.COM\u003c/code\u003e), the user name used for mapping is \u003ccode\u003eusername@EXAMPLE.COM\u003c/code\u003e (or \u003ccode\u003eusername/hostbased@EXAMPLE.COM\u003c/code\u003e, respectively), unless \u003ccode\u003einclude_realm\u003c/code\u003e has been set to 0, in which case \u003ccode\u003eusername\u003c/code\u003e (or \u003ccode\u003eusername/hostbased\u003c/code\u003e) is what is seen as the system user name when mapping.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003e\u003ccode\u003ekrb_realm\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSets the realm to match user principal names against. If this parameter is set, only users of that realm will be accepted. If it is not set, users of any realm can connect, subject to whatever user name mapping is done.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eIn addition to these settings, which can be different for different \u003ccode\u003epg_hba.conf\u003c/code\u003e entries, there is the server-wide \u003ca href=\"/docs/18/runtime-config-connection.html#GUC-KRB-CASEINS-USERS\" rel=\"nofollow\"\u003ekrb_caseins_users\u003c/a\u003e configuration parameter. If that is set to true, client principals are matched to user map entries case-insensitively. \u003ccode\u003ekrb_realm\u003c/code\u003e, if set, is also matched case-insensitively.\u003c/p\u003e\n\u003c/div\u003e","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","ContentHash":"85e73c93ece51141cad2f9f0af0b65a9fc2a9ef44b50cd5a43ecf77ca29c690b","Payload":{"description":["Use GSSAPI to authenticate the user. This is only available for TCP/IP connections. See Section 20.6 for details. It can be used in conjunction with GSSAPI encryption."],"manual_html":"\u003cdiv class=\"sect1\" id=\"GSSAPI-AUTH\"\u003e\n\u003cdiv class=\"titlepage\"\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003ch2 class=\"title\"\u003e20.6. GSSAPI Authentication \u003c/h2\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e is an industry-standard protocol for secure authentication defined in \u003ca class=\"ulink\" href=\"https://datatracker.ietf.org/doc/html/rfc2743\"\u003eRFC 2743\u003c/a\u003e. \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e supports \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e for authentication, communications encryption, or both. \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e provides automatic authentication (single sign-on) for systems that support it. The authentication itself is secure. If \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e encryption or SSL encryption is used, the data sent along the database connection will be encrypted; otherwise, it will not.\u003c/p\u003e\n\u003cp\u003eGSSAPI support has to be enabled when \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e is built; see \u003ca class=\"xref\" href=\"/docs/18/installation.html\" title=\"Chapter 17. Installation from Source Code\"\u003eChapter 17\u003c/a\u003e for more information.\u003c/p\u003e\n\u003cp\u003eWhen \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e uses \u003cspan class=\"productname\"\u003eKerberos\u003c/span\u003e, it uses a standard service principal (authentication identity) name in the format \u003ccode class=\"literal\"\u003e\u003cem class=\"replaceable\"\u003e\u003ccode\u003eservicename\u003c/code\u003e\u003c/em\u003e/\u003cem class=\"replaceable\"\u003e\u003ccode\u003ehostname\u003c/code\u003e\u003c/em\u003e@\u003cem class=\"replaceable\"\u003e\u003ccode\u003erealm\u003c/code\u003e\u003c/em\u003e\u003c/code\u003e. The principal name used by a particular installation is not encoded in the \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e server in any way; rather it is specified in the \u003cem class=\"firstterm\"\u003ekeytab\u003c/em\u003e file that the server reads to determine its identity. If multiple principals are listed in the keytab file, the server will accept any one of them. The server's realm name is the preferred realm specified in the Kerberos configuration file(s) accessible to the server.\u003c/p\u003e\n\u003cp\u003eWhen connecting, the client must know the principal name of the server it intends to connect to. The \u003cem class=\"replaceable\"\u003e\u003ccode\u003eservicename\u003c/code\u003e\u003c/em\u003e part of the principal is ordinarily \u003ccode class=\"literal\"\u003epostgres\u003c/code\u003e, but another value can be selected via \u003cspan class=\"application\"\u003elibpq\u003c/span\u003e's \u003ca class=\"xref\" href=\"/docs/18/libpq-connect.html#LIBPQ-CONNECT-KRBSRVNAME\"\u003ekrbsrvname\u003c/a\u003e connection parameter. The \u003cem class=\"replaceable\"\u003e\u003ccode\u003ehostname\u003c/code\u003e\u003c/em\u003e part is the fully qualified host name that \u003cspan class=\"application\"\u003elibpq\u003c/span\u003e is told to connect to. The realm name is the preferred realm specified in the Kerberos configuration file(s) accessible to the client.\u003c/p\u003e\n\u003cp\u003eThe client will also have a principal name for its own identity (and it must have a valid ticket for this principal). To use \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e for authentication, the client principal must be associated with a \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e database user name. The \u003ccode class=\"filename\"\u003epg_ident.conf\u003c/code\u003e configuration file can be used to map principals to user names; for example, \u003ccode class=\"literal\"\u003epgusername@realm\u003c/code\u003e could be mapped to just \u003ccode class=\"literal\"\u003epgusername\u003c/code\u003e. Alternatively, you can use the full \u003ccode class=\"literal\"\u003eusername@realm\u003c/code\u003e principal as the role name in \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e without any mapping.\u003c/p\u003e\n\u003cp\u003e\u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e also supports mapping client principals to user names by just stripping the realm from the principal. This method is supported for backwards compatibility and is strongly discouraged as it is then impossible to distinguish different users with the same user name but coming from different realms. To enable this, set \u003ccode class=\"literal\"\u003einclude_realm\u003c/code\u003e to 0. For simple single-realm installations, doing that combined with setting the \u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e parameter (which checks that the principal's realm matches exactly what is in the \u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e parameter) is still secure; but this is a less capable approach compared to specifying an explicit mapping in \u003ccode class=\"filename\"\u003epg_ident.conf\u003c/code\u003e.\u003c/p\u003e\n\u003cp\u003eThe location of the server's keytab file is specified by the \u003ca class=\"xref\" href=\"/docs/18/runtime-config-connection.html#GUC-KRB-SERVER-KEYFILE\"\u003ekrb_server_keyfile\u003c/a\u003e configuration parameter. For security reasons, it is recommended to use a separate keytab just for the \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e server rather than allowing the server to read the system keytab file. Make sure that your server keytab file is readable (and preferably only readable, not writable) by the \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e server account. (See also \u003ca class=\"xref\" href=\"/docs/18/postgres-user.html\" title=\"18.1. The PostgreSQL User Account\"\u003eSection 18.1\u003c/a\u003e.)\u003c/p\u003e\n\u003cp\u003eThe keytab file is generated using the Kerberos software; see the Kerberos documentation for details. The following example shows doing this using the \u003cspan class=\"application\"\u003ekadmin\u003c/span\u003e tool of MIT Kerberos:\u003c/p\u003e\n\u003cpre class=\"screen\"\u003e\u003ccode class=\"prompt\"\u003ekadmin% \u003c/code\u003e\u003cstrong class=\"userinput\"\u003e\u003ccode\u003eaddprinc -randkey postgres/server.my.domain.org\u003c/code\u003e\u003c/strong\u003e\n\u003ccode class=\"prompt\"\u003ekadmin% \u003c/code\u003e\u003cstrong class=\"userinput\"\u003e\u003ccode\u003ektadd -k krb5.keytab postgres/server.my.domain.org\u003c/code\u003e\u003c/strong\u003e\n\u003c/pre\u003e\n\u003cp\u003eThe following authentication options are supported for the \u003cspan class=\"productname\"\u003eGSSAPI\u003c/span\u003e authentication method:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003einclude_realm\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIf set to 0, the realm name from the authenticated user principal is stripped off before being passed through the user name mapping (\u003ca class=\"xref\" href=\"/docs/18/auth-username-maps.html\" title=\"20.2. User Name Maps\"\u003eSection 20.2\u003c/a\u003e). This is discouraged and is primarily available for backwards compatibility, as it is not secure in multi-realm environments unless \u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e is also used. It is recommended to leave \u003ccode class=\"literal\"\u003einclude_realm\u003c/code\u003e set to the default (1) and to provide an explicit mapping in \u003ccode class=\"filename\"\u003epg_ident.conf\u003c/code\u003e to convert principal names to \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e user names.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003emap\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eAllows mapping from client principals to database user names. See \u003ca class=\"xref\" href=\"/docs/18/auth-username-maps.html\" title=\"20.2. User Name Maps\"\u003eSection 20.2\u003c/a\u003e for details. For a GSSAPI/Kerberos principal, such as \u003ccode class=\"literal\"\u003eusername@EXAMPLE.COM\u003c/code\u003e (or, less commonly, \u003ccode class=\"literal\"\u003eusername/hostbased@EXAMPLE.COM\u003c/code\u003e), the user name used for mapping is \u003ccode class=\"literal\"\u003eusername@EXAMPLE.COM\u003c/code\u003e (or \u003ccode class=\"literal\"\u003eusername/hostbased@EXAMPLE.COM\u003c/code\u003e, respectively), unless \u003ccode class=\"literal\"\u003einclude_realm\u003c/code\u003e has been set to 0, in which case \u003ccode class=\"literal\"\u003eusername\u003c/code\u003e (or \u003ccode class=\"literal\"\u003eusername/hostbased\u003c/code\u003e) is what is seen as the system user name when mapping.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSets the realm to match user principal names against. If this parameter is set, only users of that realm will be accepted. If it is not set, users of any realm can connect, subject to whatever user name mapping is done.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eIn addition to these settings, which can be different for different \u003ccode class=\"filename\"\u003epg_hba.conf\u003c/code\u003e entries, there is the server-wide \u003ca class=\"xref\" href=\"/docs/18/runtime-config-connection.html#GUC-KRB-CASEINS-USERS\"\u003ekrb_caseins_users\u003c/a\u003e configuration parameter. If that is set to true, client principals are matched to user map entries case-insensitively. \u003ccode class=\"literal\"\u003ekrb_realm\u003c/code\u003e, if set, is also matched case-insensitively.\u003c/p\u003e\n\u003c/div\u003e","related":[],"sections":[],"tables":[{"columns":[{"key":"name","label":"Option or term"},{"key":"description","label":"Meaning"}],"key":"method-options","rows":[{"description":"If set to 0, the realm name from the authenticated user principal is stripped off before being passed through the user name mapping ( Section 20.2 ). This is discouraged and is primarily available for backwards compatibility, as it is not secure in multi-realm environments unless krb_realm is also used. It is recommended to leave include_realm set to the default (1) and to provide an explicit mapping in pg_ident.conf to convert principal names to PostgreSQL user names.","name":"include_realm"},{"description":"Allows mapping from client principals to database user names. See Section 20.2 for details. For a GSSAPI/Kerberos principal, such as username@EXAMPLE.COM (or, less commonly, username/hostbased@EXAMPLE.COM ), the user name used for mapping is username@EXAMPLE.COM (or username/hostbased@EXAMPLE.COM , respectively), unless include_realm has been set to 0, in which case username (or username/hostbased ) is what is seen as the system user name when mapping.","name":"map"},{"description":"Sets the realm to match user principal names against. If this parameter is set, only users of that realm will be accepted. If it is not set, users of any realm can connect, subject to whatever user name mapping is done.","name":"krb_realm"}],"title":"Documented method options and alternatives"}]}},"RequestedLocale":"zh-Hans","Fallback":true,"Versions":["10","11","12","13","14","15","16","17","18","19","20"],"Locales":["en"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}