/*------------------------------------------------------------------------- * * hba.c * Routines to handle host based authentication (that's the scheme * wherein you authenticate a user by seeing what IP address the system * says he comes from and possibly using ident). * * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * $PostgreSQL: pgsql/src/backend/libpq/hba.c,v 1.140 2005/02/26 18:43:33 tgl Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" #include #include #include #include #include #if defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || defined(HAVE_STRUCT_SOCKCRED) #include #include #endif #include #include #include #include "libpq/crypt.h" #include "libpq/libpq.h" #include "miscadmin.h" #include "nodes/pg_list.h" #include "storage/fd.h" #include "utils/flatfiles.h" #include "utils/guc.h" #define atooid(x) ((Oid) strtoul((x), NULL, 10)) /* Max size of username ident server can return */ #define IDENT_USERNAME_MAX 512 /* Standard TCP port number for Ident service. Assigned by IANA */ #define IDENT_PORT 113 /* This is used to separate values in multi-valued column strings */ #define MULTI_VALUE_SEP "\001" #define MAX_TOKEN 256 /* * These variables hold the pre-parsed contents of the hba and ident * configuration files. Each is a list of sublists, one sublist for * each (non-empty, non-comment) line of the file. Each sublist's * first item is an integer line number (so we can give somewhat-useful * location info in error messages). Remaining items are palloc'd strings, * one string per token on the line. Note there will always be at least * one token, since blank lines are not entered in the data structure. */ /* pre-parsed content of HBA config file and corresponding line #s */ static List *hba_lines = NIL; static List *hba_line_nums = NIL; /* pre-parsed content of ident usermap file and corresponding line #s */ static List *ident_lines = NIL; static List *ident_line_nums = NIL; /* pre-parsed content of group file and corresponding line #s */ static List *group_lines = NIL; static List *group_line_nums = NIL; /* pre-parsed content of user passwd file and corresponding line #s */ static List *user_lines = NIL; static List *user_line_nums = NIL; /* sorted entries so we can do binary search lookups */ static List **user_sorted = NULL; /* sorted user list, for bsearch() */ static List **group_sorted = NULL; /* sorted group list, for * bsearch() */ static int user_length; static int group_length; static void tokenize_file(const char *filename, FILE *file, List **lines, List **line_nums); static char *tokenize_inc_file(const char *outer_filename, const char *inc_filename); /* * isblank() exists in the ISO C99 spec, but it's not very portable yet, * so provide our own version. */ static bool pg_isblank(const char c) { return c == ' ' || c == '\t' || c == '\r'; } /* * Grab one token out of fp. Tokens are strings of non-blank * characters bounded by blank characters, beginning of line, and * end of line. Blank means space or tab. Return the token as * *buf. Leave file positioned at the character immediately after the * token or EOF, whichever comes first. If no more tokens on line, * return empty string as *buf and position the file to the beginning * of the next line or EOF, whichever comes first. Allow spaces in * quoted strings. Terminate on unquoted commas. Handle * comments. Treat unquoted keywords that might be user names or * database names specially, by appending a newline to them. */ static void next_token(FILE *fp, char *buf, int bufsz) { int c; char *start_buf = buf; char *end_buf = buf + (bufsz - 2); bool in_quote = false; bool was_quote = false; bool saw_quote = false; Assert(end_buf > start_buf); /* Move over initial whitespace and commas */ while ((c = getc(fp)) != EOF && (pg_isblank(c) || c == ',')) ; if (c == EOF || c == '\n') { *buf = '\0'; return; } /* * Build a token in buf of next characters up to EOF, EOL, unquoted * comma, or unquoted whitespace. */ while (c != EOF && c != '\n' && (!pg_isblank(c) || in_quote == true)) { /* skip comments to EOL */ if (c == '#' && !in_quote) { while ((c = getc(fp)) != EOF && c != '\n') ; /* If only comment, consume EOL too; return EOL */ if (c != EOF && buf == start_buf) c = getc(fp); break; } if (buf >= end_buf) { *buf = '\0'; ereport(LOG, (errcode(ERRCODE_CONFIG_FILE_ERROR), errmsg("authentication file token too long, skipping: \"%s\"", start_buf))); /* Discard remainder of line */ while ((c = getc(fp)) != EOF && c != '\n') ; break; } if (c != '"' || (c == '"' && was_quote)) *buf++ = c; /* We pass back the comma so the caller knows there is more */ if ((pg_isblank(c) || c == ',') && !in_quote) break; /* Literal double-quote is two double-quotes */ if (in_quote && c == '"') was_quote = !was_quote; else was_quote = false; if (c == '"') { in_quote = !in_quote; saw_quote = true; } c = getc(fp); } /* * Put back the char right after the token (critical in case it is * EOL, since we need to detect end-of-line at next call). */ if (c != EOF) ungetc(c, fp); *buf = '\0'; if (!saw_quote && (strcmp(start_buf, "all") == 0 || strcmp(start_buf, "sameuser") == 0 || strcmp(start_buf, "samegroup") == 0)) { /* append newline to a magical keyword */ *buf++ = '\n'; *buf = '\0'; } } /* * Tokenize file and handle file inclusion and comma lists. We have * to break apart the commas to expand any file names then * reconstruct with commas. * * The result is always a palloc'd string. If it's zero-length then * we have reached EOL. */ static char * next_token_expand(const char *filename, FILE *file) { char buf[MAX_TOKEN]; char *comma_str = pstrdup(""); bool trailing_comma; char *incbuf; int needed; do { next_token(file, buf, sizeof(buf)); if (!buf[0]) break; if (buf[strlen(buf) - 1] == ',') { trailing_comma = true; buf[strlen(buf) - 1] = '\0'; } else trailing_comma = false; /* Is this referencing a file? */ if (buf[0] == '@') incbuf = tokenize_inc_file(filename, buf + 1); else incbuf = pstrdup(buf); needed = strlen(comma_str) + strlen(incbuf) + 1; if (trailing_comma) needed++; comma_str = repalloc(comma_str, needed); strcat(comma_str, incbuf); if (trailing_comma) strcat(comma_str, MULTI_VALUE_SEP); pfree(incbuf); } while (trailing_comma); return comma_str; } /* * Free memory used by lines/tokens (i.e., structure built by tokenize_file) */ static void free_lines(List **lines, List **line_nums) { /* * Either both must be non-NULL, or both must be NULL */ Assert((*lines != NIL && *line_nums != NIL) || (*lines == NIL && *line_nums == NIL)); if (*lines) { /* * "lines" is a list of lists; each of those sublists consists of * palloc'ed tokens, so we want to free each pointed-to token in a * sublist, followed by the sublist itself, and finally the whole * list. */ ListCell *line; foreach(line, *lines) { List *ln = lfirst(line); ListCell *token; foreach(token, ln) pfree(lfirst(token)); /* free the sublist structure itself */ list_free(ln); } /* free the list structure itself */ list_free(*lines); /* clear the static variable */ *lines = NIL; } if (*line_nums) { list_free(*line_nums); *line_nums = NIL; } } static char * tokenize_inc_file(const char *outer_filename, const char *inc_filename) { char *inc_fullname; FILE *inc_file; List *inc_lines; List *inc_line_nums; ListCell *line; char *comma_str; if (is_absolute_path(inc_filename)) { /* absolute path is taken as-is */ inc_fullname = pstrdup(inc_filename); } else { /* relative path is relative to dir of calling file */ inc_fullname = (char *) palloc(strlen(outer_filename) + 1 + strlen(inc_filename) + 1); strcpy(inc_fullname, outer_filename); get_parent_directory(inc_fullname); join_path_components(inc_fullname, inc_fullname, inc_filename); canonicalize_path(inc_fullname); } inc_file = AllocateFile(inc_fullname, "r"); if (inc_file == NULL) { ereport(LOG, (errcode_for_file_access(), errmsg("could not open secondary authentication file \"@%s\" as \"%s\": %m", inc_filename, inc_fullname))); pfree(inc_fullname); /* return single space, it matches nothing */ return pstrdup(" "); } /* There is possible recursion here if the file contains @ */ tokenize_file(inc_fullname, inc_file, &inc_lines, &inc_line_nums); FreeFile(inc_file); pfree(inc_fullname); /* Create comma-separated string from List */ comma_str = pstrdup(""); foreach(line, inc_lines) { List *token_list = (List *) lfirst(line); ListCell *token; foreach(token, token_list) { int oldlen = strlen(comma_str); int needed; needed = oldlen + strlen(lfirst(token)) + 1; if (oldlen > 0) needed++; comma_str = repalloc(comma_str, needed); if (oldlen > 0) strcat(comma_str, MULTI_VALUE_SEP); strcat(comma_str, lfirst(token)); } } free_lines(&inc_lines, &inc_line_nums); /* if file is empty, return single space rather than empty string */ if (strlen(comma_str) == 0) { pfree(comma_str); return pstrdup(" "); } return comma_str; } /* * Tokenize the given file, storing the resulting data into two lists: * a list of sublists, each sublist containing the tokens in a line of * the file, and a list of line numbers. * * filename must be the absolute path to the target file. */ static void tokenize_file(const char *filename, FILE *file, List **lines, List **line_nums) { List *current_line = NIL; int line_number = 1; char *buf; *lines = *line_nums = NIL; while (!feof(file)) { buf = next_token_expand(filename, file); /* add token to list, unless we are at EOL or comment start */ if (buf[0]) { if (current_line == NIL) { /* make a new line List, record its line number */ current_line = lappend(current_line, buf); *lines = lappend(*lines, current_line); *line_nums = lappend_int(*line_nums, line_number); } else { /* append token to current line's list */ current_line = lappend(current_line, buf); } } else { /* we are at real or logical EOL, so force a new line List */ current_line = NIL; /* Advance line number whenever we reach EOL */ line_number++; /* Don't forget to pfree the next_token_expand result */ pfree(buf); } } } /* * Compare two lines based on their user/group names. * * Used for qsort() sorting. */ static int user_group_qsort_cmp(const void *list1, const void *list2) { char *user1 = linitial(*(List **) list1); char *user2 = linitial(*(List **) list2); return strcmp(user1, user2); } /* * Compare two lines based on their user/group names. * * Used for bsearch() lookup. */ static int user_group_bsearch_cmp(const void *user, const void *list) { char *user2 = linitial(*(List **) list); return strcmp(user, user2); } /* * Lookup a group name in the pg_group file */ static List ** get_group_line(const char *group) { /* On some versions of Solaris, bsearch of zero items dumps core */ if (group_length == 0) return NULL; return (List **) bsearch((void *) group, (void *) group_sorted, group_length, sizeof(List *), user_group_bsearch_cmp); } /* * Lookup a user name in the pg_shadow file */ List ** get_user_line(const char *user) { /* On some versions of Solaris, bsearch of zero items dumps core */ if (user_length == 0) return NULL; return (List **) bsearch((void *) user, (void *) user_sorted, user_length, sizeof(List *), user_group_bsearch_cmp); } /* * Does user belong to group? */ static bool check_group(char *group, char *user) { List **line; ListCell *line_item; char *usesysid; if ((line = get_user_line(user)) == NULL) return false; /* if user not exist, say "no" */ /* Skip over username to get usesysid */ usesysid = (char *) lsecond(*line); if ((line = get_group_line(group)) == NULL) return false; /* if group not exist, say "no" */ /* skip over the group name, examine all the member usesysid's */ for_each_cell(line_item, lnext(list_head(*line))) { if (strcmp((char *) lfirst(line_item), usesysid) == 0) return true; } return false; } /* * Check comma user list for a specific user, handle group names. */ static bool check_user(char *user, char *param_str) { char *tok; for (tok = strtok(param_str, MULTI_VALUE_SEP); tok != NULL; tok = strtok(NULL, MULTI_VALUE_SEP)) { if (tok[0] == '+') { if (check_group(tok + 1, user)) return true; } else if (strcmp(tok, user) == 0 || strcmp(tok, "all\n") == 0) return true; } return false; } /* * Check to see if db/user combination matches param string. */ static bool check_db(char *dbname, char *user, char *param_str) { char *tok; for (tok = strtok(param_str, MULTI_VALUE_SEP); tok != NULL; tok = strtok(NULL, MULTI_VALUE_SEP)) { if (strcmp(tok, "all\n") == 0) return true; else if (strcmp(tok, "sameuser\n") == 0) { if (strcmp(dbname, user) == 0) return true; } else if (strcmp(tok, "samegroup\n") == 0) { if (check_group(dbname, user)) return true; } else if (strcmp(tok, dbname) == 0) return true; } return false; } /* * Scan the rest of a host record (after the mask field) * and return the interpretation of it as *userauth_p, *auth_arg_p, and * *error_p. *line_item points to the next token of the line, and is * advanced over successfully-read tokens. */ static void parse_hba_auth(ListCell **line_item, UserAuth *userauth_p, char **auth_arg_p, bool *error_p) { char *token; *auth_arg_p = NULL; if (!*line_item) { *error_p = true; return; } token = lfirst(*line_item); if (strcmp(token, "trust") == 0) *userauth_p = uaTrust; else if (strcmp(token, "ident") == 0) *userauth_p = uaIdent; else if (strcmp(token, "password") == 0) *userauth_p = uaPassword; else if (strcmp(token, "krb4") == 0) *userauth_p = uaKrb4; else if (strcmp(token, "krb5") == 0) *userauth_p = uaKrb5; else if (strcmp(token, "reject") == 0) *userauth_p = uaReject; else if (strcmp(token, "md5") == 0) *userauth_p = uaMD5; else if (strcmp(token, "crypt") == 0) *userauth_p = uaCrypt; #ifdef USE_PAM else if (strcmp(token, "pam") == 0) *userauth_p = uaPAM; #endif else { *error_p = true; return; } *line_item = lnext(*line_item); /* Get the authentication argument token, if any */ if (*line_item) { token = lfirst(*line_item); *auth_arg_p = pstrdup(token); *line_item = lnext(*line_item); /* If there is more on the line, it is an error */ if (*line_item) *error_p = true; } } /* * Process one line from the hba config file. * * See if it applies to a connection from a host with IP address port->raddr * to a database named port->database. If so, return *found_p true * and fill in the auth arguments into the appropriate port fields. * If not, leave *found_p as it was. If the record has a syntax error, * return *error_p true, after issuing a message to the log. If no error, * leave *error_p as it was. */ static void parse_hba(List *line, int line_num, hbaPort *port, bool *found_p, bool *error_p) { char *token; char *db; char *user; struct addrinfo *gai_result; struct addrinfo hints; int ret; struct sockaddr_storage addr; struct sockaddr_storage mask; char *cidr_slash; ListCell *line_item; line_item = list_head(line); /* Check the record type. */ token = lfirst(line_item); if (strcmp(token, "local") == 0) { /* Get the database. */ line_item = lnext(line_item); if (!line_item) goto hba_syntax; db = lfirst(line_item); /* Get the user. */ line_item = lnext(line_item); if (!line_item) goto hba_syntax; user = lfirst(line_item); line_item = lnext(line_item); if (!line_item) goto hba_syntax; /* Read the rest of the line. */ parse_hba_auth(&line_item, &port->auth_method, &port->auth_arg, error_p); if (*error_p) goto hba_syntax; /* Disallow auth methods that always need TCP/IP sockets to work */ if (port->auth_method == uaKrb4 || port->auth_method == uaKrb5) goto hba_syntax; /* Does not match if connection isn't AF_UNIX */ if (!IS_AF_UNIX(port->raddr.addr.ss_family)) return; } else if (strcmp(token, "host") == 0 || strcmp(token, "hostssl") == 0 || strcmp(token, "hostnossl") == 0) { if (token[4] == 's') /* "hostssl" */ { #ifdef USE_SSL /* Record does not match if we are not on an SSL connection */ if (!port->ssl) return; /* Placeholder to require specific SSL level, perhaps? */ /* Or a client certificate */ /* Since we were on SSL, proceed as with normal 'host' mode */ #else /* We don't accept this keyword at all if no SSL support */ goto hba_syntax; #endif } #ifdef USE_SSL else if (token[4] == 'n') /* "hostnossl" */ { /* Record does not match if we are on an SSL connection */ if (port->ssl) return; } #endif /* Get the database. */ line_item = lnext(line_item); if (!line_item) goto hba_syntax; db = lfirst(line_item); /* Get the user. */ line_item = lnext(line_item); if (!line_item) goto hba_syntax; user = lfirst(line_item); /* Read the IP address field. (with or without CIDR netmask) */ line_item = lnext(line_item); if (!line_item) goto hba_syntax; token = lfirst(line_item); /* Check if it has a CIDR suffix and if so isolate it */ cidr_slash = strchr(token, '/'); if (cidr_slash) *cidr_slash = '\0'; /* Get the IP address either way */ hints.ai_flags = AI_NUMERICHOST; hints.ai_family = PF_UNSPEC; hints.ai_socktype = 0; hints.ai_protocol = 0; hints.ai_addrlen = 0; hints.ai_canonname = NULL; hints.ai_addr = NULL; hints.ai_next = NULL; ret = getaddrinfo_all(token, NULL, &hints, &gai_result); if (ret || !gai_result) { ereport(LOG, (errcode(ERRCODE_CONFIG_FILE_ERROR), errmsg("invalid IP address \"%s\" in file \"%s\" line %d: %s", token, HbaFileName, line_num, gai_strerror(ret)))); if (cidr_slash) *cidr_slash = '/'; if (gai_result) freeaddrinfo_all(hints.ai_family, gai_result); goto hba_other_error; } if (cidr_slash) *cidr_slash = '/'; memcpy(&addr, gai_result->ai_addr, gai_result->ai_addrlen); freeaddrinfo_all(hints.ai_family, gai_result); /* Get the netmask */ if (cidr_slash) { if (SockAddr_cidr_mask(&mask, cidr_slash + 1, addr.ss_family) < 0) goto hba_syntax; } else { /* Read the mask field. */ line_item = lnext(line_item); if (!line_item) goto hba_syntax; token = lfirst(line_item); ret = getaddrinfo_all(token, NULL, &hints, &gai_result); if (ret || !gai_result) { ereport(LOG, (errcode(ERRCODE_CONFIG_FILE_ERROR), errmsg("invalid IP mask \"%s\" in file \"%s\" line %d: %s", token, HbaFileName, line_num, gai_strerror(ret)))); if (gai_result) freeaddrinfo_all(hints.ai_family, gai_result); goto hba_other_error; } memcpy(&mask, gai_result->ai_addr, gai_result->ai_addrlen); freeaddrinfo_all(hints.ai_family, gai_result); if (addr.ss_family != mask.ss_family) { ereport(LOG, (errcode(ERRCODE_CONFIG_FILE_ERROR), errmsg("IP address and mask do not match in file \"%s\" line %d", HbaFileName, line_num))); goto hba_other_error; } } if (addr.ss_family != port->raddr.addr.ss_family) { /* * Wrong address family. We allow only one case: if the file * has IPv4 and the port is IPv6, promote the file address to * IPv6 and try to match that way. */ #ifdef HAVE_IPV6 if (addr.ss_family == AF_INET && port->raddr.addr.ss_family == AF_INET6) { promote_v4_to_v6_addr(&addr); promote_v4_to_v6_mask(&mask); } else #endif /* HAVE_IPV6 */ { /* Line doesn't match client port, so ignore it. */ return; } } /* Ignore line if client port is not in the matching addr range. */ if (!rangeSockAddr(&port->raddr.addr, &addr, &mask)) return; /* Read the rest of the line. */ line_item = lnext(line_item); if (!line_item) goto hba_syntax; parse_hba_auth(&line_item, &port->auth_method, &port->auth_arg, error_p); if (*error_p) goto hba_syntax; } else goto hba_syntax; /* Does the entry match database and user? */ if (!check_db(port->database_name, port->user_name, db)) return; if (!check_user(port->user_name, user)) return; /* Success */ *found_p = true; return; hba_syntax: if (line_item) ereport(LOG, (errcode(ERRCODE_CONFIG_FILE_ERROR), errmsg("invalid entry in file \"%s\" at line %d, token \"%s\"", HbaFileName, line_num, (char *) lfirst(line_item)))); else ereport(LOG, (errcode(ERRCODE_CONFIG_FILE_ERROR), errmsg("missing field in file \"%s\" at end of line %d", HbaFileName, line_num))); /* Come here if suitable message already logged */ hba_other_error: *error_p = true; } /* * Scan the (pre-parsed) hba file line by line, looking for a match * to the port's connection request. */ static bool check_hba(hbaPort *port) { bool found_entry = false; bool error = false; ListCell *line; ListCell *line_num; forboth(line, hba_lines, line_num, hba_line_nums) { parse_hba(lfirst(line), lfirst_int(line_num), port, &found_entry, &error); if (found_entry || error) break; } if (!error) { /* If no matching entry was found, synthesize 'reject' entry. */ if (!found_entry) port->auth_method = uaReject; return true; } else return false; } /* * Load group/user name mapping file */ void load_group(void) { char *filename; FILE *group_file; /* Discard any old data */ if (group_lines || group_line_nums) free_lines(&group_lines, &group_line_nums); if (group_sorted) pfree(group_sorted); group_sorted = NULL; group_length = 0; /* Read in the file contents */ filename = group_getflatfilename(); group_file = AllocateFile(filename, "r"); if (group_file == NULL) { /* no complaint if not there */ if (errno != ENOENT) ereport(LOG, (errcode_for_file_access(), errmsg("could not open file \"%s\": %m", filename))); pfree(filename); return; } tokenize_file(filename, group_file, &group_lines, &group_line_nums); FreeFile(group_file); pfree(filename); /* create sorted lines for binary searching */ group_length = list_length(group_lines); if (group_length) { int i = 0; ListCell *line; group_sorted = palloc(group_length * sizeof(List *)); foreach(line, group_lines) group_sorted[i++] = lfirst(line); qsort((void *) group_sorted, group_length, sizeof(List *), user_group_qsort_cmp); } } /* * Load user/password mapping file */ void load_user(void) { char *filename; FILE *user_file; /* Discard any old data */ if (user_lines || user_line_nums) free_lines(&user_lines, &user_line_nums); if (user_sorted) pfree(user_sorted); user_sorted = NULL; user_length = 0; /* Read in the file contents */ filename = user_getflatfilename(); user_file = AllocateFile(filename, "r"); if (user_file == NULL) { /* no complaint if not there */ if (errno != ENOENT) ereport(LOG, (errcode_for_file_access(), errmsg("could not open file \"%s\": %m", filename))); pfree(filename); return; } tokenize_file(filename, user_file, &user_lines, &user_line_nums); FreeFile(user_file); pfree(filename); /* create sorted lines for binary searching */ user_length = list_length(user_lines); if (user_length) { int i = 0; ListCell *line; user_sorted = palloc(user_length * sizeof(List *)); foreach(line, user_lines) user_sorted[i++] = lfirst(line); qsort((void *) user_sorted, user_length, sizeof(List *), user_group_qsort_cmp); } } /* * Read the config file and create a List of Lists of tokens in the file. */ void load_hba(void) { FILE *file; if (hba_lines || hba_line_nums) free_lines(&hba_lines, &hba_line_nums); file = AllocateFile(HbaFileName, "r"); /* Failure is fatal since with no HBA entries we can do nothing... */ if (file == NULL) ereport(FATAL, (errcode_for_file_access(), errmsg("could not open configuration file \"%s\": %m", HbaFileName))); tokenize_file(HbaFileName, file, &hba_lines, &hba_line_nums); FreeFile(file); } /* * Read and parse one line from the flat pg_database file. * * Returns TRUE on success, FALSE if EOF; bad data causes elog(FATAL). * * Output parameters: * dbname: gets database name (must be of size NAMEDATALEN bytes) * dboid: gets database OID * dbtablespace: gets database's default tablespace's OID * * This is not much related to the other functions in hba.c, but we put it * here because it uses the next_token() infrastructure. */ bool read_pg_database_line(FILE *fp, char *dbname, Oid *dboid, Oid *dbtablespace) { char buf[MAX_TOKEN]; if (feof(fp)) return false; next_token(fp, buf, sizeof(buf)); if (!buf[0]) return false; if (strlen(buf) >= NAMEDATALEN) elog(FATAL, "bad data in flat pg_database file"); strcpy(dbname, buf); next_token(fp, buf, sizeof(buf)); if (!isdigit((unsigned char) buf[0])) elog(FATAL, "bad data in flat pg_database file"); *dboid = atooid(buf); next_token(fp, buf, sizeof(buf)); if (!isdigit((unsigned char) buf[0])) elog(FATAL, "bad data in flat pg_database file"); *dbtablespace = atooid(buf); /* discard datfrozenxid */ next_token(fp, buf, sizeof(buf)); if (!isdigit((unsigned char) buf[0])) elog(FATAL, "bad data in flat pg_database file"); /* expect EOL next */ next_token(fp, buf, sizeof(buf)); if (buf[0]) elog(FATAL, "bad data in flat pg_database file"); return true; } /* * Process one line from the ident config file. * * Take the line and compare it to the needed map, pg_user and ident_user. * *found_p and *error_p are set according to our results. */ static void parse_ident_usermap(List *line, int line_number, const char *usermap_name, const char *pg_user, const char *ident_user, bool *found_p, bool *error_p) { ListCell *line_item; char *token; char *file_map; char *file_pguser; char *file_ident_user; *found_p = false; *error_p = false; Assert(line != NIL); line_item = list_head(line); /* Get the map token (must exist) */ token = lfirst(line_item); file_map = token; /* Get the ident user token (must be provided) */ line_item = lnext(line_item); if (!line) goto ident_syntax; token = lfirst(line_item); file_ident_user = token; /* Get the PG username token */ line_item = lnext(line_item); if (!line) goto ident_syntax; token = lfirst(line_item); file_pguser = token; /* Match? */ if (strcmp(file_map, usermap_name) == 0 && strcmp(file_pguser, pg_user) == 0 && strcmp(file_ident_user, ident_user) == 0) *found_p = true; return; ident_syntax: if (line_item) ereport(LOG, (errcode(ERRCODE_CONFIG_FILE_ERROR), errmsg("invalid entry in file \"%s\" at line %d, token \"%s\"", IdentFileName, line_number, (const char *) lfirst(line_item)))); else ereport(LOG, (errcode(ERRCODE_CONFIG_FILE_ERROR), errmsg("missing entry in file \"%s\" at end of line %d", IdentFileName, line_number))); *error_p = true; } /* * Scan the (pre-parsed) ident usermap file line by line, looking for a match * * See if the user with ident username "ident_user" is allowed to act * as Postgres user "pguser" according to usermap "usermap_name". * * Special case: For usermap "sameuser", don't look in the usermap * file. That's an implied map where "pguser" must be identical to * "ident_user" in order to be authorized. * * Iff authorized, return true. */ static bool check_ident_usermap(const char *usermap_name, const char *pg_user, const char *ident_user) { bool found_entry = false, error = false; if (usermap_name == NULL || usermap_name[0] == '\0') { ereport(LOG, (errcode(ERRCODE_CONFIG_FILE_ERROR), errmsg("cannot use Ident authentication without usermap field"))); found_entry = false; } else if (strcmp(usermap_name, "sameuser\n") == 0) { if (strcmp(pg_user, ident_user) == 0) found_entry = true; else found_entry = false; } else { ListCell *line_cell, *num_cell; forboth(line_cell, ident_lines, num_cell, ident_line_nums) { parse_ident_usermap(lfirst(line_cell), lfirst_int(num_cell), usermap_name, pg_user, ident_user, &found_entry, &error); if (found_entry || error) break; } } return found_entry; } /* * Read the ident config file and create a List of Lists of tokens in the file. */ void load_ident(void) { FILE *file; if (ident_lines || ident_line_nums) free_lines(&ident_lines, &ident_line_nums); file = AllocateFile(IdentFileName, "r"); if (file == NULL) { /* not fatal ... we just won't do any special ident maps */ ereport(LOG, (errcode_for_file_access(), errmsg("could not open Ident usermap file \"%s\": %m", IdentFileName))); } else { tokenize_file(IdentFileName, file, &ident_lines, &ident_line_nums); FreeFile(file); } } /* * Parse the string "*ident_response" as a response from a query to an Ident * server. If it's a normal response indicating a user name, return true * and store the user name at *ident_user. If it's anything else, * return false. */ static bool interpret_ident_response(const char *ident_response, char *ident_user) { const char *cursor = ident_response; /* Cursor into * *ident_response */ /* * Ident's response, in the telnet tradition, should end in crlf * (\r\n). */ if (strlen(ident_response) < 2) return false; else if (ident_response[strlen(ident_response) - 2] != '\r') return false; else { while (*cursor != ':' && *cursor != '\r') cursor++; /* skip port field */ if (*cursor != ':') return false; else { /* We're positioned to colon before response type field */ char response_type[80]; int i; /* Index into *response_type */ cursor++; /* Go over colon */ while (pg_isblank(*cursor)) cursor++; /* skip blanks */ i = 0; while (*cursor != ':' && *cursor != '\r' && !pg_isblank(*cursor) && i < (int) (sizeof(response_type) - 1)) response_type[i++] = *cursor++; response_type[i] = '\0'; while (pg_isblank(*cursor)) cursor++; /* skip blanks */ if (strcmp(response_type, "USERID") != 0) return false; else { /* * It's a USERID response. Good. "cursor" should be * pointing to the colon that precedes the operating * system type. */ if (*cursor != ':') return false; else { cursor++; /* Go over colon */ /* Skip over operating system field. */ while (*cursor != ':' && *cursor != '\r') cursor++; if (*cursor != ':') return false; else { int i; /* Index into *ident_user */ cursor++; /* Go over colon */ while (pg_isblank(*cursor)) cursor++; /* skip blanks */ /* Rest of line is user name. Copy it over. */ i = 0; while (*cursor != '\r' && i < IDENT_USERNAME_MAX) ident_user[i++] = *cursor++; ident_user[i] = '\0'; return true; } } } } } } /* * Talk to the ident server on host "remote_ip_addr" and find out who * owns the tcp connection from his port "remote_port" to port * "local_port_addr" on host "local_ip_addr". Return the user name the * ident server gives as "*ident_user". * * IP addresses and port numbers are in network byte order. * * 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) { int sock_fd, /* File descriptor for socket on which we * talk to Ident */ rc; /* Return code from a locally called * function */ bool ident_return; char remote_addr_s[NI_MAXHOST]; char remote_port[NI_MAXSERV]; char local_addr_s[NI_MAXHOST]; char local_port[NI_MAXSERV]; char ident_port[NI_MAXSERV]; char ident_query[80]; char ident_response[80 + IDENT_USERNAME_MAX]; struct addrinfo *ident_serv = NULL, *la = NULL, hints; /* * Might look a little weird to first convert it to text and then back * to sockaddr, but it's protocol independent. */ getnameinfo_all(&remote_addr.addr, remote_addr.salen, remote_addr_s, sizeof(remote_addr_s), remote_port, sizeof(remote_port), NI_NUMERICHOST | NI_NUMERICSERV); getnameinfo_all(&local_addr.addr, local_addr.salen, local_addr_s, sizeof(local_addr_s), local_port, sizeof(local_port), NI_NUMERICHOST | NI_NUMERICSERV); snprintf(ident_port, sizeof(ident_port), "%d", IDENT_PORT); hints.ai_flags = AI_NUMERICHOST; hints.ai_family = remote_addr.addr.ss_family; hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = 0; hints.ai_addrlen = 0; hints.ai_canonname = NULL; hints.ai_addr = NULL; hints.ai_next = NULL; rc = getaddrinfo_all(remote_addr_s, ident_port, &hints, &ident_serv); if (rc || !ident_serv) { if (ident_serv) freeaddrinfo_all(hints.ai_family, ident_serv); return false; /* we don't expect this to happen */ } hints.ai_flags = AI_NUMERICHOST; hints.ai_family = local_addr.addr.ss_family; hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = 0; hints.ai_addrlen = 0; hints.ai_canonname = NULL; hints.ai_addr = NULL; hints.ai_next = NULL; rc = getaddrinfo_all(local_addr_s, NULL, &hints, &la); if (rc || !la) { if (la) freeaddrinfo_all(hints.ai_family, la); return false; /* we don't expect this to happen */ } sock_fd = socket(ident_serv->ai_family, ident_serv->ai_socktype, ident_serv->ai_protocol); if (sock_fd < 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not create socket for Ident connection: %m"))); ident_return = false; goto ident_inet_done; } /* * Bind to the address which the client originally contacted, * otherwise the ident server won't be able to match up the right * connection. This is necessary if the PostgreSQL server is running * on an IP alias. */ rc = bind(sock_fd, la->ai_addr, la->ai_addrlen); if (rc != 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not bind to local address \"%s\": %m", local_addr_s))); ident_return = false; goto ident_inet_done; } rc = connect(sock_fd, ident_serv->ai_addr, ident_serv->ai_addrlen); if (rc != 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not connect to Ident server at address \"%s\", port %s: %m", remote_addr_s, ident_port))); ident_return = false; goto ident_inet_done; } /* The query we send to the Ident server */ snprintf(ident_query, sizeof(ident_query), "%s,%s\r\n", remote_port, local_port); /* loop in case send is interrupted */ do { rc = send(sock_fd, ident_query, strlen(ident_query), 0); } while (rc < 0 && errno == EINTR); if (rc < 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not send query to Ident server at address \"%s\", port %s: %m", remote_addr_s, ident_port))); ident_return = false; goto ident_inet_done; } do { rc = recv(sock_fd, ident_response, sizeof(ident_response) - 1, 0); } while (rc < 0 && errno == EINTR); if (rc < 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not receive response from Ident server at address \"%s\", port %s: %m", remote_addr_s, ident_port))); ident_return = false; goto ident_inet_done; } ident_response[rc] = '\0'; ident_return = interpret_ident_response(ident_response, ident_user); if (!ident_return) ereport(LOG, (errmsg("invalidly formatted response from Ident server: \"%s\"", ident_response))); ident_inet_done: if (sock_fd >= 0) closesocket(sock_fd); freeaddrinfo_all(remote_addr.addr.ss_family, ident_serv); freeaddrinfo_all(local_addr.addr.ss_family, la); return ident_return; } /* * Ask kernel about the credentials of the connecting process and * determine the symbolic name of the corresponding user. * * Returns either true and the username put into "ident_user", * or false if we were unable to determine the username. */ #ifdef HAVE_UNIX_SOCKETS static bool ident_unix(int sock, char *ident_user) { #if defined(HAVE_GETPEEREID) /* OpenBSD style: */ uid_t uid; gid_t gid; struct passwd *pass; errno = 0; if (getpeereid(sock, &uid, &gid) != 0) { /* We didn't get a valid credentials struct. */ ereport(LOG, (errcode_for_socket_access(), errmsg("could not get peer credentials: %m"))); return false; } pass = getpwuid(uid); if (pass == NULL) { ereport(LOG, (errmsg("local user with ID %d does not exist", (int) uid))); return false; } StrNCpy(ident_user, pass->pw_name, IDENT_USERNAME_MAX + 1); return true; #elif defined(SO_PEERCRED) /* Linux style: use getsockopt(SO_PEERCRED) */ struct ucred peercred; ACCEPT_TYPE_ARG3 so_len = sizeof(peercred); struct passwd *pass; errno = 0; if (getsockopt(sock, SOL_SOCKET, SO_PEERCRED, &peercred, &so_len) != 0 || so_len != sizeof(peercred)) { /* We didn't get a valid credentials struct. */ ereport(LOG, (errcode_for_socket_access(), errmsg("could not get peer credentials: %m"))); return false; } pass = getpwuid(peercred.uid); if (pass == NULL) { ereport(LOG, (errmsg("local user with ID %d does not exist", (int) peercred.uid))); return false; } StrNCpy(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; /* Credentials structure */ #if defined(HAVE_STRUCT_CMSGCRED) typedef struct cmsgcred Cred; #define cruid cmcred_uid #elif defined(HAVE_STRUCT_FCRED) typedef struct fcred Cred; #define cruid fc_uid #elif defined(HAVE_STRUCT_SOCKCRED) typedef struct sockcred Cred; #define cruid sc_uid #endif Cred *cred; /* Compute size without padding */ char cmsgmem[ALIGN(sizeof(struct cmsghdr)) + ALIGN(sizeof(Cred))]; /* for NetBSD */ /* Point to start of first structure */ struct cmsghdr *cmsg = (struct cmsghdr *) cmsgmem; struct iovec iov; char buf; struct passwd *pw; memset(&msg, 0, sizeof(msg)); msg.msg_iov = &iov; msg.msg_iovlen = 1; msg.msg_control = (char *) cmsg; msg.msg_controllen = sizeof(cmsgmem); memset(cmsg, 0, sizeof(cmsgmem)); /* * The one character which is received here is not meaningful; its * purposes is only to make sure that recvmsg() blocks long enough for * the other side to send its credentials. */ iov.iov_base = &buf; iov.iov_len = 1; if (recvmsg(sock, &msg, 0) < 0 || cmsg->cmsg_len < sizeof(cmsgmem) || cmsg->cmsg_type != SCM_CREDS) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not get peer credentials: %m"))); return false; } cred = (Cred *) CMSG_DATA(cmsg); pw = getpwuid(cred->cruid); if (pw == NULL) { ereport(LOG, (errmsg("local user with ID %d does not exist", (int) cred->cruid))); return false; } StrNCpy(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->auth_arg 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). */ 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: #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; } ereport(DEBUG2, (errmsg("Ident protocol identifies remote user as \"%s\"", ident_user))); if (check_ident_usermap(port->auth_arg, port->user_name, ident_user)) return STATUS_OK; else return STATUS_ERROR; } /* * Determine what authentication method should be used when accessing database * "database" from frontend "raddr", user "user". Return the method and * an optional argument (stored in fields of *port), and STATUS_OK. * * Note that STATUS_ERROR indicates a problem with the hba config file. * If the file is OK but does not contain any entry matching the request, * we return STATUS_OK and method = uaReject. */ int hba_getauthmethod(hbaPort *port) { if (check_hba(port)) return STATUS_OK; else return STATUS_ERROR; }