From 6f9192df61e183826211ad2eaf325c6de5cf3656 Mon Sep 17 00:00:00 2001 From: Magnus Hagander Date: Sat, 19 Mar 2011 18:44:35 +0100 Subject: [PATCH] Rename ident authentication over local connections to peer This removes an overloading of two authentication options where one is very secure (peer) and one is often insecure (ident). Peer is also the name used in libpq from 9.1 to specify the same type of authentication. Also make initdb select peer for local connections when ident is chosen, and ident for TCP connections when peer is chosen. ident keyword in pg_hba.conf is still accepted and maps to peer authentication. --- doc/src/sgml/client-auth.sgml | 96 +++++++++++++++-------- doc/src/sgml/runtime.sgml | 2 +- src/backend/libpq/auth.c | 112 +++++++++++---------------- src/backend/libpq/hba.c | 24 +++++- src/backend/libpq/pg_hba.conf.sample | 4 +- src/bin/initdb/initdb.c | 19 +++++ src/include/libpq/hba.h | 3 +- 7 files changed, 156 insertions(+), 104 deletions(-) diff --git a/doc/src/sgml/client-auth.sgml b/doc/src/sgml/client-auth.sgml index 4ca723fe1a..afbd9feb37 100644 --- a/doc/src/sgml/client-auth.sgml +++ b/doc/src/sgml/client-auth.sgml @@ -457,16 +457,29 @@ hostnossl database user ident - Obtain the operating system user name of the client (for - TCP/IP connections by contacting the ident server on the - client, for local connections by getting it from the - operating system) and check if it matches the requested - database user name. + Obtain the operating system user name of the client + by contacting the ident server on the client + and check if it matches the requested database user name. + Ident authentication can only be used on TCP/IP + connections. When specified for local connections, peer + authentication will be used instead. See for details. + + peer + + + Obtain the operating system user name from the operating system + and check if it matches the requested database user name. + This is only available for local connections. + See for details. + + + + ldap @@ -1200,7 +1213,7 @@ omicron bryanh guest1 - Ident-based Authentication + Ident Authentication ident @@ -1208,13 +1221,19 @@ omicron bryanh guest1 The ident authentication method works by obtaining the client's - operating system user name and using it as the allowed database user - name (with an optional user name mapping). - The determination of the client's - user name is the security-critical point, and it works differently - depending on the connection type, as described below. + operating system user name from an ident server and using it as + the allowed database user name (with an optional user name mapping). + This is only supported on TCP/IP connections. + + + When ident is specified for a local (non-TCP/IP) connection, + peer authentication (see ) will be + used instead. + + + The following configuration options are supported for ident: @@ -1230,9 +1249,6 @@ omicron bryanh guest1 - - Ident Authentication Over TCP/IP - The Identification Protocol is described in RFC 1413. Virtually every Unix-like @@ -1275,36 +1291,48 @@ omicron bryanh guest1 since PostgreSQL does not have any way to decrypt the returned string to determine the actual user name. - + - - Ident Authentication Over Local Sockets + + Peer Authentication + + + peer + - On systems supporting SO_PEERCRED requests for + The peer authentication method works by obtaining the client's + operating system user name from the kernel and using it as the + allowed database user name (with optional user name mapping). This + is only supported on local connections. + + + + The following configuration options are supported for peer: + + + map + + + Allows for mapping between system and database user names. See + for details. + + + + + + + + Peer authentication is only available on systems supporting + SO_PEERCRED requests for Unix-domain sockets (currently Linux, FreeBSD, NetBSD, OpenBSD, - BSD/OS, and Solaris), ident authentication can also - be applied to local connections. + BSD/OS, and Solaris). PostgreSQL uses SO_PEERCRED to find out the operating system name of the connected client process. - In this case, no security risk is added by - using ident authentication; indeed it is a preferable choice for - local connections on such systems. - - On systems without SO_PEERCRED requests, ident - authentication is only available for TCP/IP connections. As a - work-around, it is possible to specify the localhost address 127.0.0.1 and make connections to this - address. This method is trustworthy to the extent that you trust - the local ident server. - - - diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index f77673791b..b5ad1011cb 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -148,7 +148,7 @@ postgres$ initdb -D /usr/local/pgsql/data mode is not used; or modify the generated pg_hba.conf file after running initdb, but before you start the server for the first time. (Other - reasonable approaches include using ident authentication + reasonable approaches include using peer authentication or file system permissions to restrict connections. See for more information.) diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c index af43c2a7cb..5f56020cc7 100644 --- a/src/backend/libpq/auth.c +++ b/src/backend/libpq/auth.c @@ -60,7 +60,10 @@ static int recv_and_check_password_packet(Port *port); /* Standard TCP port number for Ident service. Assigned by IANA */ #define IDENT_PORT 113 -static int authident(hbaPort *port); +static int ident_inet(hbaPort *port); +#ifdef HAVE_UNIX_SOCKETS +static int auth_peer(hbaPort *port); +#endif /*---------------------------------------------------------------- @@ -269,6 +272,9 @@ auth_failed(Port *port, int status) case uaIdent: errstr = gettext_noop("Ident authentication failed for user \"%s\""); break; + case uaPeer: + errstr = gettext_noop("Peer authentication failed for user \"%s\""); + break; case uaPassword: case uaMD5: errstr = gettext_noop("password authentication failed for user \"%s\""); @@ -506,11 +512,12 @@ ClientAuthentication(Port *port) #endif break; - case uaIdent: + case uaPeer: +#ifdef HAVE_UNIX_SOCKETS /* - * If we are doing ident on unix-domain sockets, use SCM_CREDS - * only if it is defined and SO_PEERCRED isn't. + * If we are doing peer on unix-domain sockets, use SCM_CREDS only + * if it is defined and SO_PEERCRED isn't. */ #if !defined(HAVE_GETPEEREID) && !defined(SO_PEERCRED) && \ (defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || \ @@ -535,7 +542,14 @@ ClientAuthentication(Port *port) sendAuthRequest(port, AUTH_REQ_SCM_CREDS); } #endif - status = authident(port); + status = auth_peer(port); +#else /* HAVE_UNIX_SOCKETS */ + Assert(false); +#endif + break; + + case uaIdent: + status = ident_inet(port); break; case uaMD5: @@ -1599,11 +1613,12 @@ interpret_ident_response(const char *ident_response, * * But iff we're unable to get the information from ident, return false. */ -static bool -ident_inet(const SockAddr remote_addr, - const SockAddr local_addr, - char *ident_user) +static int +ident_inet(hbaPort *port) { + const SockAddr remote_addr = port->raddr; + const SockAddr local_addr = port->laddr; + char ident_user[IDENT_USERNAME_MAX + 1]; pgsocket sock_fd, /* File descriptor for socket on which we talk * to Ident */ rc; /* Return code from a locally called function */ @@ -1646,7 +1661,7 @@ ident_inet(const SockAddr remote_addr, { if (ident_serv) pg_freeaddrinfo_all(hints.ai_family, ident_serv); - return false; /* we don't expect this to happen */ + return STATUS_ERROR; /* we don't expect this to happen */ } hints.ai_flags = AI_NUMERICHOST; @@ -1662,7 +1677,7 @@ ident_inet(const SockAddr remote_addr, { if (la) pg_freeaddrinfo_all(hints.ai_family, la); - return false; /* we don't expect this to happen */ + return STATUS_ERROR; /* we don't expect this to happen */ } sock_fd = socket(ident_serv->ai_family, ident_serv->ai_socktype, @@ -1751,7 +1766,11 @@ ident_inet_done: closesocket(sock_fd); pg_freeaddrinfo_all(remote_addr.addr.ss_family, ident_serv); pg_freeaddrinfo_all(local_addr.addr.ss_family, la); - return ident_return; + + if (ident_return) + /* Success! Check the usermap */ + return check_usermap(port->hba->usermap, port->user_name, ident_user, false); + return STATUS_ERROR; } /* @@ -1763,9 +1782,12 @@ ident_inet_done: */ #ifdef HAVE_UNIX_SOCKETS -static bool -ident_unix(int sock, char *ident_user) +static int +auth_peer(hbaPort *port) { + int sock = port->sock; + char ident_user[IDENT_USERNAME_MAX + 1]; + #if defined(HAVE_GETPEEREID) /* OpenBSD style: */ uid_t uid; @@ -1779,7 +1801,7 @@ ident_unix(int sock, char *ident_user) ereport(LOG, (errcode_for_socket_access(), errmsg("could not get peer credentials: %m"))); - return false; + return STATUS_ERROR; } pass = getpwuid(uid); @@ -1789,12 +1811,11 @@ ident_unix(int sock, char *ident_user) ereport(LOG, (errmsg("local user with ID %d does not exist", (int) uid))); - return false; + return STATUS_ERROR; } strlcpy(ident_user, pass->pw_name, IDENT_USERNAME_MAX + 1); - return true; #elif defined(SO_PEERCRED) /* Linux style: use getsockopt(SO_PEERCRED) */ struct ucred peercred; @@ -1809,7 +1830,7 @@ ident_unix(int sock, char *ident_user) ereport(LOG, (errcode_for_socket_access(), errmsg("could not get peer credentials: %m"))); - return false; + return STATUS_ERROR; } pass = getpwuid(peercred.uid); @@ -1819,12 +1840,11 @@ ident_unix(int sock, char *ident_user) ereport(LOG, (errmsg("local user with ID %d does not exist", (int) peercred.uid))); - return false; + return STATUS_ERROR; } strlcpy(ident_user, pass->pw_name, IDENT_USERNAME_MAX + 1); - return true; #elif defined(HAVE_GETPEERUCRED) /* Solaris > 10 */ uid_t uid; @@ -1837,7 +1857,7 @@ ident_unix(int sock, char *ident_user) ereport(LOG, (errcode_for_socket_access(), errmsg("could not get peer credentials: %m"))); - return false; + return STATUS_ERROR; } if ((uid = ucred_geteuid(ucred)) == -1) @@ -1845,7 +1865,7 @@ ident_unix(int sock, char *ident_user) ereport(LOG, (errcode_for_socket_access(), errmsg("could not get effective UID from peer credentials: %m"))); - return false; + return STATUS_ERROR; } ucred_free(ucred); @@ -1856,12 +1876,11 @@ ident_unix(int sock, char *ident_user) ereport(LOG, (errmsg("local user with ID %d does not exist", (int) uid))); - return false; + return STATUS_ERROR; } strlcpy(ident_user, pass->pw_name, IDENT_USERNAME_MAX + 1); - return true; #elif defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || (defined(HAVE_STRUCT_SOCKCRED) && defined(LOCAL_CREDS)) struct msghdr msg; @@ -1913,7 +1932,7 @@ ident_unix(int sock, char *ident_user) ereport(LOG, (errcode_for_socket_access(), errmsg("could not get peer credentials: %m"))); - return false; + return STATUS_ERROR; } cred = (Cred *) CMSG_DATA(cmsg); @@ -1925,59 +1944,22 @@ ident_unix(int sock, char *ident_user) ereport(LOG, (errmsg("local user with ID %d does not exist", (int) cred->cruid))); - return false; + return STATUS_ERROR; } strlcpy(ident_user, pw->pw_name, IDENT_USERNAME_MAX + 1); - return true; #else ereport(LOG, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("Ident authentication is not supported on local connections on this platform"))); - return false; -#endif -} -#endif /* HAVE_UNIX_SOCKETS */ - - -/* - * Determine the username of the initiator of the connection described - * by "port". Then look in the usermap file under the usermap - * port->hba->usermap and see if that user is equivalent to Postgres user - * port->user. - * - * Return STATUS_OK if yes, STATUS_ERROR if no match (or couldn't get info). - */ -static int -authident(hbaPort *port) -{ - char ident_user[IDENT_USERNAME_MAX + 1]; - - switch (port->raddr.addr.ss_family) - { - case AF_INET: -#ifdef HAVE_IPV6 - case AF_INET6: + return STATUS_ERROR; #endif - if (!ident_inet(port->raddr, port->laddr, ident_user)) - return STATUS_ERROR; - break; - -#ifdef HAVE_UNIX_SOCKETS - case AF_UNIX: - if (!ident_unix(port->sock, ident_user)) - return STATUS_ERROR; - break; -#endif - - default: - return STATUS_ERROR; - } return check_usermap(port->hba->usermap, port->user_name, ident_user, false); } +#endif /* HAVE_UNIX_SOCKETS */ /*---------------------------------------------------------------- diff --git a/src/backend/libpq/hba.c b/src/backend/libpq/hba.c index 1b3a71431c..2def6cea89 100644 --- a/src/backend/libpq/hba.c +++ b/src/backend/libpq/hba.c @@ -1060,6 +1060,8 @@ parse_hba_line(List *line, int line_num, HbaLine *parsedline) parsedline->auth_method = uaTrust; else if (strcmp(token, "ident") == 0) parsedline->auth_method = uaIdent; + else if (strcmp(token, "peer") == 0) + parsedline->auth_method = uaPeer; else if (strcmp(token, "password") == 0) parsedline->auth_method = uaPassword; else if (strcmp(token, "krb5") == 0) @@ -1137,6 +1139,14 @@ parse_hba_line(List *line, int line_num, HbaLine *parsedline) return false; } + /* + * XXX: When using ident on local connections, change it to peer, for + * backwards compatibility. + */ + if (parsedline->conntype == ctLocal && + parsedline->auth_method == uaIdent) + parsedline->auth_method = uaPeer; + /* Invalid authentication combinations */ if (parsedline->conntype == ctLocal && parsedline->auth_method == uaKrb5) @@ -1160,6 +1170,17 @@ parse_hba_line(List *line, int line_num, HbaLine *parsedline) return false; } + if (parsedline->conntype != ctLocal && + parsedline->auth_method == uaPeer) + { + ereport(LOG, + (errcode(ERRCODE_CONFIG_FILE_ERROR), + errmsg("peer authentication is only supported on local sockets"), + errcontext("line %d of configuration file \"%s\"", + line_num, HbaFileName))); + return false; + } + /* * SSPI authentication can never be enabled on ctLocal connections, * because it's only supported on Windows, where ctLocal isn't supported. @@ -1203,11 +1224,12 @@ parse_hba_line(List *line, int line_num, HbaLine *parsedline) if (strcmp(token, "map") == 0) { if (parsedline->auth_method != uaIdent && + parsedline->auth_method != uaPeer && parsedline->auth_method != uaKrb5 && parsedline->auth_method != uaGSS && parsedline->auth_method != uaSSPI && parsedline->auth_method != uaCert) - INVALID_AUTH_OPTION("map", gettext_noop("ident, krb5, gssapi, sspi and cert")); + INVALID_AUTH_OPTION("map", gettext_noop("ident, peer, krb5, gssapi, sspi and cert")); parsedline->usermap = pstrdup(c); } else if (strcmp(token, "clientcert") == 0) diff --git a/src/backend/libpq/pg_hba.conf.sample b/src/backend/libpq/pg_hba.conf.sample index 87f84991bc..0a90b68c10 100644 --- a/src/backend/libpq/pg_hba.conf.sample +++ b/src/backend/libpq/pg_hba.conf.sample @@ -41,7 +41,7 @@ # directly connected to. # # METHOD can be "trust", "reject", "md5", "password", "gss", "sspi", -# "krb5", "ident", "pam", "ldap", "radius" or "cert". Note that +# "krb5", "ident", "peer", "pam", "ldap", "radius" or "cert". Note that # "password" sends passwords in clear text; "md5" is preferred since # it sends encrypted passwords. # @@ -75,7 +75,7 @@ # TYPE DATABASE USER ADDRESS METHOD @remove-line-for-nolocal@# "local" is for Unix domain socket connections only -@remove-line-for-nolocal@local all all @authmethod@ +@remove-line-for-nolocal@local all all @authmethodlocal@ # IPv4 local connections: host all all 127.0.0.1/32 @authmethod@ # IPv6 local connections: diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c index 7a4b698b99..d509b1311d 100644 --- a/src/bin/initdb/initdb.c +++ b/src/bin/initdb/initdb.c @@ -82,6 +82,7 @@ static char *username = ""; static bool pwprompt = false; static char *pwfilename = NULL; static char *authmethod = ""; +static char *authmethodlocal = ""; static bool debug = false; static bool noclean = false; static bool show_setting = false; @@ -1076,6 +1077,9 @@ setup_config(void) conflines = replace_token(conflines, "@authmethod@", authmethod); + conflines = replace_token(conflines, + "@authmethodlocal@", + authmethodlocal); conflines = replace_token(conflines, "@authcomment@", @@ -2637,6 +2641,7 @@ main(int argc, char *argv[]) } if (strcmp(authmethod, "md5") && + strcmp(authmethod, "peer") && strcmp(authmethod, "ident") && strcmp(authmethod, "trust") && #ifdef USE_PAM @@ -2666,6 +2671,20 @@ main(int argc, char *argv[]) exit(1); } + /* + * When ident is specified, use peer for local connections. Mirrored, when + * peer is specified, use ident for TCP connections. + */ + if (strcmp(authmethod, "ident") == 0) + authmethodlocal = "peer"; + else if (strcmp(authmethod, "peer") == 0) + { + authmethodlocal = "peer"; + authmethod = "ident"; + } + else + authmethodlocal = authmethod; + if (strlen(pg_data) == 0) { pgdenv = getenv("PGDATA"); diff --git a/src/include/libpq/hba.h b/src/include/libpq/hba.h index aa60d8d4f1..b92dc0d3a4 100644 --- a/src/include/libpq/hba.h +++ b/src/include/libpq/hba.h @@ -29,7 +29,8 @@ typedef enum UserAuth uaPAM, uaLDAP, uaCert, - uaRADIUS + uaRADIUS, + uaPeer } UserAuth; typedef enum IPCompareMethod -- 2.40.0