From efb6f4a4f9b627b9447f5cd8e955d43a7066c30c Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Fri, 20 Jan 2023 11:21:55 +0900 Subject: Support the same patterns for pg-user in pg_ident.conf as in pg_hba.conf While pg_hba.conf has support for non-literal username matches, and this commit extends the capabilities that are supported for the PostgreSQL user listed in an ident entry part of pg_ident.conf, with support for: 1. The "all" keyword, where all the requested users are allowed. 2. Membership checks using the + prefix. 3. Using a regex to match against multiple roles. 1. is a feature that has been requested by Jelte Fennema, 2. something that has been mentioned independently by Andrew Dunstan, and 3. is something I came up with while discussing how to extend the first one, whose implementation is facilitated by 8fea868. This allows matching certain system users against many different postgres users with a single line in pg_ident.conf. Without this, one would need one line for each of the postgres users that a system user can log in as, which can be cumbersome to maintain. Tests are added to the TAP test of peer authentication to provide coverage for all that. Note that this introduces a set of backward-incompatible changes to be able to detect the new patterns, for the following cases: - A role named "all". - A role prefixed with '+' characters, which is something that would not have worked in HBA entries anyway. - A role prefixed by a slash character, similarly to 8fea868. Any of these can be still be handled by using quotes in the Postgres role defined in an ident entry. A huge advantage of this change is that the code applies the same checks for the Postgres roles in HBA and ident entries, via the common routine check_role(). **This compatibility change should be mentioned in the release notes.** Author: Jelte Fennema Discussion: https://postgr.es/m/DBBPR83MB0507FEC2E8965012990A80D0F7FC9@DBBPR83MB0507.EURPRD83.prod.outlook.com --- src/backend/libpq/hba.c | 98 ++++++++++++++------- src/test/authentication/t/003_peer.pl | 160 ++++++++++++++++++++++++++++++++-- 2 files changed, 220 insertions(+), 38 deletions(-) (limited to 'src') diff --git a/src/backend/libpq/hba.c b/src/backend/libpq/hba.c index 029b8e44838..adedbd31280 100644 --- a/src/backend/libpq/hba.c +++ b/src/backend/libpq/hba.c @@ -73,8 +73,10 @@ typedef struct } tokenize_error_callback_arg; #define token_has_regexp(t) (t->regex != NULL) +#define token_is_member_check(t) (!t->quoted && t->string[0] == '+') #define token_is_keyword(t, k) (!t->quoted && strcmp(t->string, k) == 0) #define token_matches(t, k) (strcmp(t->string, k) == 0) +#define token_matches_insensitive(t,k) (pg_strcasecmp(t->string, k) == 0) /* * Memory context holding the list of TokenizedAuthLines when parsing @@ -995,10 +997,11 @@ is_member(Oid userid, const char *role) * * Each AuthToken listed is checked one-by-one. Keywords are processed * first (these cannot have regular expressions), followed by regular - * expressions (if any) and the exact match. + * expressions (if any), the case-insensitive match (if requested) and + * the exact match. */ static bool -check_role(const char *role, Oid roleid, List *tokens) +check_role(const char *role, Oid roleid, List *tokens, bool case_insensitive) { ListCell *cell; AuthToken *tok; @@ -1006,7 +1009,7 @@ check_role(const char *role, Oid roleid, List *tokens) foreach(cell, tokens) { tok = lfirst(cell); - if (!tok->quoted && tok->string[0] == '+') + if (token_is_member_check(tok)) { if (is_member(roleid, tok->string + 1)) return true; @@ -1018,6 +1021,11 @@ check_role(const char *role, Oid roleid, List *tokens) if (regexec_auth_token(role, tok, 0, NULL) == REG_OKAY) return true; } + else if (case_insensitive) + { + if (token_matches_insensitive(tok, role)) + return true; + } else if (token_matches(tok, role)) return true; } @@ -2614,7 +2622,7 @@ check_hba(hbaPort *port) hba->databases)) continue; - if (!check_role(port->user_name, roleid, hba->roles)) + if (!check_role(port->user_name, roleid, hba->roles, false)) continue; /* Found a record that matched! */ @@ -2804,7 +2812,7 @@ parse_ident_line(TokenizedAuthLine *tok_line, int elevel) /* * Now that the field validation is done, compile a regex from the user - * token, if necessary. + * tokens, if necessary. */ if (regcomp_auth_token(parsedline->system_user, file_name, line_num, err_msg, elevel)) @@ -2813,6 +2821,13 @@ parse_ident_line(TokenizedAuthLine *tok_line, int elevel) return NULL; } + if (regcomp_auth_token(parsedline->pg_user, file_name, line_num, + err_msg, elevel)) + { + /* err_msg includes the error to report */ + return NULL; + } + return parsedline; } @@ -2827,6 +2842,8 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name, const char *pg_user, const char *system_user, bool case_insensitive, bool *found_p, bool *error_p) { + Oid roleid; + *found_p = false; *error_p = false; @@ -2834,6 +2851,9 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name, /* Line does not match the map name we're looking for, so just abort */ return; + /* Get the target role's OID. Note we do not error out for bad role. */ + roleid = get_role_oid(pg_user, true); + /* Match? */ if (token_has_regexp(identLine->system_user)) { @@ -2845,7 +2865,8 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name, int r; regmatch_t matches[2]; char *ofs; - char *expanded_pg_user; + AuthToken *expanded_pg_user_token; + bool created_temporary_token = false; r = regexec_auth_token(system_user, identLine->system_user, 2, matches); if (r) @@ -2865,8 +2886,16 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name, return; } - if ((ofs = strstr(identLine->pg_user->string, "\\1")) != NULL) + /* + * Replace \1 with the first captured group unless the field already + * has some special meaning, like a group membership or a regexp-based + * check. + */ + if (!token_is_member_check(identLine->pg_user) && + !token_has_regexp(identLine->pg_user) && + (ofs = strstr(identLine->pg_user->string, "\\1")) != NULL) { + char *expanded_pg_user; int offset; /* substitution of the first argument requested */ @@ -2891,46 +2920,53 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name, system_user + matches[1].rm_so, matches[1].rm_eo - matches[1].rm_so); strcat(expanded_pg_user, ofs + 2); - } - else - { - /* no substitution, so copy the match */ - expanded_pg_user = pstrdup(identLine->pg_user->string); - } - /* - * now check if the username actually matched what the user is trying - * to connect as - */ - if (case_insensitive) - { - if (pg_strcasecmp(expanded_pg_user, pg_user) == 0) - *found_p = true; + /* + * Mark the token as quoted, so it will only be compared literally + * and not for some special meaning, such as "all" or a group + * membership check. + */ + expanded_pg_user_token = make_auth_token(expanded_pg_user, true); + created_temporary_token = true; + pfree(expanded_pg_user); } else { - if (strcmp(expanded_pg_user, pg_user) == 0) - *found_p = true; + expanded_pg_user_token = identLine->pg_user; } - pfree(expanded_pg_user); + + /* check the Postgres user */ + *found_p = check_role(pg_user, roleid, + list_make1(expanded_pg_user_token), + case_insensitive); + + if (created_temporary_token) + free_auth_token(expanded_pg_user_token); return; } else { - /* Not regular expression, so make complete match */ + /* + * Not a regular expression, so make a complete match. If the system + * user does not match, just leave. + */ if (case_insensitive) { - if (pg_strcasecmp(identLine->pg_user->string, pg_user) == 0 && - pg_strcasecmp(identLine->system_user->string, system_user) == 0) - *found_p = true; + if (!token_matches_insensitive(identLine->system_user, + system_user)) + return; } else { - if (strcmp(identLine->pg_user->string, pg_user) == 0 && - strcmp(identLine->system_user->string, system_user) == 0) - *found_p = true; + if (!token_matches(identLine->system_user, system_user)) + return; } + + /* check the Postgres user */ + *found_p = check_role(pg_user, roleid, + list_make1(identLine->pg_user), + case_insensitive); } } diff --git a/src/test/authentication/t/003_peer.pl b/src/test/authentication/t/003_peer.pl index e6f5fdba165..a6be651ea7f 100644 --- a/src/test/authentication/t/003_peer.pl +++ b/src/test/authentication/t/003_peer.pl @@ -98,8 +98,13 @@ if (find_in_log( plan skip_all => 'peer authentication is not supported on this platform'; } -# Add a database role, to use for the user name map. +# Add a database role and a group, to use for the user name map. $node->safe_psql('postgres', qq{CREATE ROLE testmapuser LOGIN}); +$node->safe_psql('postgres', "CREATE ROLE testmapgroup NOLOGIN"); +$node->safe_psql('postgres', "GRANT testmapgroup TO testmapuser"); +# Note the double quotes here. +$node->safe_psql('postgres', 'CREATE ROLE "testmapgroupliteral\\1" LOGIN'); +$node->safe_psql('postgres', 'GRANT "testmapgroupliteral\\1" TO testmapuser'); # Extract as well the system user for the user name map. my $system_user = @@ -123,12 +128,56 @@ test_role($node, qq{testmapuser}, 'peer', 0, 'with user name map', log_like => [qr/connection authenticated: identity="$system_user" method=peer/]); +# Tests with the "all" keyword. +reset_pg_ident($node, 'mypeermap', $system_user, 'all'); + +test_role( + $node, + qq{testmapuser}, + 'peer', + 0, + 'with keyword "all" as database user in user name map', + log_like => + [qr/connection authenticated: identity="$system_user" method=peer/]); + +# Tests with the "all" keyword, but quoted (no effect here). +reset_pg_ident($node, 'mypeermap', $system_user, '"all"'); + +test_role( + $node, + qq{testmapuser}, + 'peer', + 2, + 'with quoted keyword "all" as database user in user name map', + log_like => [qr/no match in usermap "mypeermap" for user "testmapuser"/]); + +# Success as the regexp of the database user matches +reset_pg_ident($node, 'mypeermap', $system_user, qq{/^testm.*\$}); +test_role( + $node, + qq{testmapuser}, + 'peer', + 0, + 'with regexp of database user in user name map', + log_like => + [qr/connection authenticated: identity="$system_user" method=peer/]); + +# Failure as the regexp of the database user does not match. +reset_pg_ident($node, 'mypeermap', $system_user, qq{/^doesnotmatch.*\$}); +test_role( + $node, + qq{testmapuser}, + 'peer', + 2, + 'with bad regexp of database user in user name map', + log_like => [qr/no match in usermap "mypeermap" for user "testmapuser"/]); + # Test with regular expression in user name map. # Extract the last 3 characters from the system_user # or the entire system_user (if its length is <= -3). my $regex_test_string = substr($system_user, -3); -# Success as the regular expression matches. +# Success as the system user regular expression matches. reset_pg_ident($node, 'mypeermap', qq{/^.*$regex_test_string\$}, 'testmapuser'); test_role( @@ -136,10 +185,33 @@ test_role( qq{testmapuser}, 'peer', 0, - 'with regular expression in user name map', + 'with regexp of system user in user name map', log_like => [qr/connection authenticated: identity="$system_user" method=peer/]); +# Success as both regular expressions match. +reset_pg_ident($node, 'mypeermap', qq{/^.*$regex_test_string\$}, + qq{/^testm.*\$}); +test_role( + $node, + qq{testmapuser}, + 'peer', + 0, + 'with regexps for both system and database user in user name map', + log_like => + [qr/connection authenticated: identity="$system_user" method=peer/]); + +# Success as the regular expression matches and database role is the "all" +# keyword. +reset_pg_ident($node, 'mypeermap', qq{/^.*$regex_test_string\$}, 'all'); +test_role( + $node, + qq{testmapuser}, + 'peer', + 0, + 'with regexp of system user and keyword "all" in user name map', + log_like => + [qr/connection authenticated: identity="$system_user" method=peer/]); # Success as the regular expression matches and \1 is replaced in the given # subexpression. @@ -179,17 +251,91 @@ test_role( ]); # Concatenate system_user to system_user. -$regex_test_string = $system_user . $system_user; +my $bad_regex_test_string = $system_user . $system_user; -# Failure as the regular expression does not match. -reset_pg_ident($node, 'mypeermap', qq{/^.*$regex_test_string\$}, +# Failure as the regexp of system user does not match. +reset_pg_ident($node, 'mypeermap', qq{/^.*$bad_regex_test_string\$}, 'testmapuser'); test_role( $node, qq{testmapuser}, 'peer', 2, - 'with regular expression in user name map', + 'with regexp of system user in user name map', + log_like => [qr/no match in usermap "mypeermap" for user "testmapuser"/]); + +# Test using a group role match for the database user. +reset_pg_ident($node, 'mypeermap', $system_user, '+testmapgroup'); + +test_role($node, qq{testmapuser}, 'peer', 0, 'plain user with group', + log_like => + [qr/connection authenticated: identity="$system_user" method=peer/]); + +test_role( + $node, qq{testmapgroup}, 'peer', 2, + 'group user with group', + log_like => [qr/role "testmapgroup" is not permitted to log in/]); + +# Now apply quotes to the group match, nullifying its effect. +reset_pg_ident($node, 'mypeermap', $system_user, '"+testmapgroup"'); +test_role( + $node, + qq{testmapuser}, + 'peer', + 2, + 'plain user with quoted group name', log_like => [qr/no match in usermap "mypeermap" for user "testmapuser"/]); +# Test using a regexp for the system user, with a group membership +# check for the database user. +reset_pg_ident($node, 'mypeermap', qq{/^.*$regex_test_string\$}, + '+testmapgroup'); + +test_role( + $node, + qq{testmapuser}, + 'peer', + 0, + 'regexp of system user as group member', + log_like => + [qr/connection authenticated: identity="$system_user" method=peer/]); + +test_role( + $node, + qq{testmapgroup}, + 'peer', + 2, + 'regexp of system user as non-member of group', + log_like => [qr/role "testmapgroup" is not permitted to log in/]); + +# Test that membership checks and regexes will use literal \1 instead of +# replacing it, as subexpression replacement is not allowed in this case. +reset_pg_ident($node, 'mypeermap', qq{/^.*$regex_test_string(.*)\$}, + '+testmapgroupliteral\\1'); + +test_role( + $node, + qq{testmapuser}, + 'peer', + 0, + 'membership check with literal \1', + log_like => + [qr/connection authenticated: identity="$system_user" method=peer/]); + +# Do the same with a quoted regular expression for the database user this +# time. No replacement of \1 is done. +reset_pg_ident( + $node, 'mypeermap', + qq{/^.*$regex_test_string(.*)\$}, + '"/^testmapgroupliteral\\\\1$"'); + +test_role( + $node, + 'testmapgroupliteral\\\\1', + 'peer', + 0, + 'regexp of database user with literal \1', + log_like => + [qr/connection authenticated: identity="$system_user" method=peer/]); + done_testing(); -- cgit v1.2.3