1 /* $Cambridge: exim/src/src/lookups/ldap.c,v 1.5 2004/12/21 12:00:59 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2004 */
8 /* See the file NOTICE for conditions of use and distribution. */
10 /* Many thanks to Stuart Lynne for contributing the original code for this
11 driver. Further contibutions from Michael Haardt, Brian Candler, Barry
12 Pederson, Peter Savitch and Christian Kellner. Particular thanks to Brian for
13 researching how to handle the different kinds of error. */
17 #include "lf_functions.h"
21 /* We can't just compile this code and allow the library mechanism to omit the
22 functions if they are not wanted, because we need to have the LDAP headers
23 available for compiling. Therefore, compile these functions only if LOOKUP_LDAP
24 is defined. However, some compilers don't like compiling empty modules, so keep
25 them happy with a dummy when skipping the rest. Make it reference itself to
26 stop picky compilers complaining that it is unused, and put in a dummy argument
27 to stop even pickier compilers complaining about infinite loops. */
30 static void dummy(int x) { dummy(x-1); }
34 /* Include LDAP headers */
40 /* Annoyingly, the different LDAP libraries handle errors in different ways,
41 and some other things too. There doesn't seem to be an automatic way of
42 distinguishing between them. Local/Makefile should contain a setting of
43 LDAP_LIB_TYPE, which in turn causes appropriate macros to be defined for the
44 different kinds. Those that matter are:
47 LDAP_LIB_SOLARIS with synonym LDAP_LIB_SOLARIS7
50 These others may be defined, but are in fact the default, so are not tested:
56 #if defined(LDAP_LIB_SOLARIS7) && ! defined(LDAP_LIB_SOLARIS)
57 #define LDAP_LIB_SOLARIS
61 /* Just in case LDAP_NO_LIMIT is not defined by some of these libraries. */
64 #define LDAP_NO_LIMIT 0
68 /* Just in case LDAP_DEREF_NEVER is not defined */
70 #ifndef LDAP_DEREF_NEVER
71 #define LDAP_DEREF_NEVER 0
75 /* Four types of LDAP search are implemented */
77 #define SEARCH_LDAP_MULTIPLE 0 /* Get attributes from multiple entries */
78 #define SEARCH_LDAP_SINGLE 1 /* Get attributes from one entry only */
79 #define SEARCH_LDAP_DN 2 /* Get just the DN from one entry */
80 #define SEARCH_LDAP_AUTH 3 /* Just checking for authentication */
82 /* In all 4 cases, the DN is left in $ldap_dn (which post-dates the
83 SEARCH_LDAP_DN lookup). */
86 /* Structure and anchor for caching connections. */
88 typedef struct ldap_connection {
89 struct ldap_connection *next;
98 static LDAP_CONNECTION *ldap_connections = NULL;
102 /*************************************************
103 * Internal search function *
104 *************************************************/
106 /* This is the function that actually does the work. It is called (indirectly
107 via control_ldap_search) from eldap_find(), eldapauth_find(), eldapdn_find(),
108 and eldapm_find(), with a difference in the "search_type" argument.
110 The case of eldapauth_find() is special in that all it does is do
111 authentication, returning OK or FAIL as appropriate. This isn't used as a
112 lookup. Instead, it is called from expand.c as an expansion condition test.
114 The DN from a successful lookup is placed in $ldap_dn. This feature postdates
115 the provision of the SEARCH_LDAP_DN facility for returning just the DN as the
119 ldap_url the URL to be looked up
120 server server host name, when URL contains none
121 s_port server port, used when URL contains no name
122 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
123 SEARCH_LDAP_SINGLE allows values from one entry only
124 SEARCH_LDAP_DN gets the DN from one entry
125 res set to point at the result (not used for ldapauth)
126 errmsg set to point a message if result is not OK
127 defer_break set TRUE if no more servers to be tried after a DEFER
128 user user name for authentication, or NULL
129 password password for authentication, or NULL
130 sizelimit max number of entries returned, or 0 for no limit
131 timelimit max time to wait, or 0 for no limit
132 tcplimit max time for network activity, e.g. connect, or 0 for OS default
133 deference the dereference option, which is one of
134 LDAP_DEREF_{NEVER,SEARCHING,FINDING,ALWAYS}
136 Returns: OK or FAIL or DEFER
137 FAIL is given only if a lookup was performed successfully, but
142 perform_ldap_search(uschar *ldap_url, uschar *server, int s_port, int search_type,
143 uschar **res, uschar **errmsg, BOOL *defer_break, uschar *user, uschar *password,
144 int sizelimit, int timelimit, int tcplimit, int dereference)
146 LDAPURLDesc *ludp = NULL;
147 LDAPMessage *result = NULL;
149 LDAP_CONNECTION *lcp;
151 struct timeval timeout;
152 struct timeval *timeoutptr = NULL;
163 uschar *error1 = NULL; /* string representation of errcode (static) */
164 uschar *error2 = NULL; /* error message from the server */
165 uschar *matched = NULL; /* partially matched DN */
168 int error_yield = DEFER;
170 int rc, ldap_rc, ldap_parse_rc;
175 BOOL attribute_found = FALSE;
179 debug_printf("perform_ldap_search: ldap%s URL = \"%s\" server=%s port=%d "
180 "sizelimit=%d timelimit=%d tcplimit=%d\n",
181 (search_type == SEARCH_LDAP_MULTIPLE)? "m" :
182 (search_type == SEARCH_LDAP_DN)? "dn" :
183 (search_type == SEARCH_LDAP_AUTH)? "auth" : "",
184 ldap_url, server, s_port, sizelimit, timelimit, tcplimit);
186 /* Check if LDAP thinks the URL is a valid LDAP URL. We assume that if the LDAP
187 library that is in use doesn't recognize, say, "ldapi", it will barf here. */
189 if (!ldap_is_ldap_url(CS ldap_url))
191 *errmsg = string_sprintf("ldap_is_ldap_url: not an LDAP url \"%s\"\n",
193 goto RETURN_ERROR_BREAK;
198 if ((rc = ldap_url_parse(CS ldap_url, &ludp)) != 0)
200 *errmsg = string_sprintf("ldap_url_parse: (error %d) parsing \"%s\"\n", rc,
202 goto RETURN_ERROR_BREAK;
205 /* If the host name is empty, take it from the separate argument, if one is
206 given. OpenLDAP 2.0.6 sets an unset hostname to "" rather than empty, but
207 expects NULL later in ldap_init() to mean "default", annoyingly. In OpenLDAP
208 2.0.11 this has changed (it uses NULL). */
210 if ((ludp->lud_host == NULL || ludp->lud_host[0] == 0) && server != NULL)
217 host = US ludp->lud_host;
218 if (host != NULL && host[0] == 0) host = NULL;
219 port = ludp->lud_port;
222 DEBUG(D_lookup) debug_printf("after ldap_url_parse: host=%s port=%d\n",
225 if (port == 0) port = LDAP_PORT; /* Default if none given */
226 sprintf(CS porttext, ":%d", port); /* For messages */
228 /* If the "host name" is actually a path, we are going to connect using a Unix
229 socket, regardless of whether "ldapi" was actually specified or not. This means
230 that a Unix socket can be declared in eldap_default_servers, and "traditional"
231 LDAP queries using just "ldap" can be used ("ldaps" is similarly overridden).
232 The path may start with "/" or it may already be escaped as "%2F" if it was
233 actually declared that way in eldap_default_servers. (I did it that way the
234 first time.) If the host name is not a path, the use of "ldapi" causes an
235 error, except in the default case. (But lud_scheme doesn't seem to exist in
240 if ((host[0] == '/' || Ustrncmp(host, "%2F", 3) == 0))
243 porttext[0] = 0; /* Remove port from messages */
246 #if defined LDAP_LIB_OPENLDAP2
247 else if (strncmp(ludp->lud_scheme, "ldapi", 5) == 0)
249 *errmsg = string_sprintf("ldapi requires an absolute path (\"%s\" given)",
256 /* Count the attributes; we need this later to tell us how to format results */
258 for (attrp = USS ludp->lud_attrs; attrp != NULL && *attrp != NULL; attrp++)
261 /* See if we can find a cached connection to this host. The port is not
262 relevant for ldapi. The host name pointer is set to NULL if no host was given
263 (implying the library default), rather than to the empty string. Note that in
264 this case, there is no difference between ldap and ldapi. */
266 for (lcp = ldap_connections; lcp != NULL; lcp = lcp->next)
268 if ((host == NULL) != (lcp->host == NULL) ||
269 (host != NULL && strcmpic(lcp->host, host) != 0))
271 if (ldapi || port == lcp->port) break;
274 /* Use this network timeout in any requests. */
278 timeout.tv_sec = tcplimit;
280 timeoutptr = &timeout;
283 /* If no cached connection found, we must open a connection to the server. If
284 the server name is actually an absolute path, we set ldapi=TRUE above. This
285 requests connection via a Unix socket. However, as far as I know, only OpenLDAP
286 supports the use of sockets, and the use of ldap_initialize(). */
293 /* --------------------------- OpenLDAP ------------------------ */
295 /* There seems to be a preference under OpenLDAP for ldap_initialize()
296 instead of ldap_init(), though I have as yet been unable to find
297 documentation that says this. (OpenLDAP documentation is sparse to
298 non-existent). So we handle OpenLDAP differently here. Also, support for
299 ldapi seems to be OpenLDAP-only at present. */
301 #ifdef LDAP_LIB_OPENLDAP2
303 /* We now need an empty string for the default host. Get some store in which
304 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
305 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
306 than the host name + "ldaps:///" plus : and a port number, say 20 + the
307 length of the host name. What we get should accommodate both, easily. */
309 uschar *shost = (host == NULL)? US"" : host;
310 uschar *init_url = store_get(20 + 3 * Ustrlen(shost));
313 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
314 contain the path name, with slashes escaped as %2F. */
319 init_ptr = init_url + 8;
320 Ustrcpy(init_url, "ldapi://");
321 while ((ch = *shost++) != 0)
325 Ustrncpy(init_ptr, "%2F", 3);
328 else *init_ptr++ = ch;
333 /* This is not an ldapi call. Just build a URI with the protocol type, host
338 init_ptr = Ustrchr(ldap_url, '/');
339 Ustrncpy(init_url, ldap_url, init_ptr - ldap_url);
340 init_ptr = init_url + (init_ptr - ldap_url);
341 sprintf(CS init_ptr, "//%s:%d/", shost, port);
344 /* Call ldap_initialize() and check the result */
346 DEBUG(D_lookup) debug_printf("ldap_initialize with URL %s\n", init_url);
347 rc = ldap_initialize(&ld, CS init_url);
348 if (rc != LDAP_SUCCESS)
350 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
354 store_reset(init_url); /* Might as well save memory when we can */
357 /* ------------------------- Not OpenLDAP ---------------------- */
359 /* For libraries other than OpenLDAP, use ldap_init(). */
361 #else /* LDAP_LIB_OPENLDAP2 */
362 ld = ldap_init(CS host, port);
363 #endif /* LDAP_LIB_OPENLDAP2 */
365 /* -------------------------------------------------------------- */
368 /* Handle failure to initialize */
372 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
373 host, porttext, strerror(errno));
377 /* Set the TCP connect time limit if available. This is something that is
378 in Netscape SDK v4.1; I don't know about other libraries. */
380 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
383 int timeout1000 = tcplimit*1000;
384 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
388 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
389 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)¬imeout);
393 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
395 #ifdef LDAP_OPT_NETWORK_TIMEOUT
397 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
400 /* I could not get TLS to work until I set the version to 3. That version
401 seems to be the default nowadays. The RFC is dated 1997, so I would hope
402 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
403 been set, go for v3 if we can. */
405 if (eldap_version < 0)
408 eldap_version = LDAP_VERSION3;
414 #ifdef LDAP_OPT_PROTOCOL_VERSION
415 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
418 DEBUG(D_lookup) debug_printf("initialized for LDAP (v%d) server %s%s\n",
419 eldap_version, host, porttext);
421 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
422 for "ldaps" and soft otherwise. */
424 #ifdef LDAP_OPT_X_TLS
428 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
430 tls_option = LDAP_OPT_X_TLS_HARD;
431 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_HARD set\n");
435 tls_option = LDAP_OPT_X_TLS_TRY;
436 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_TRY set\n");
438 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
440 #endif /* LDAP_OPT_X_TLS */
442 /* Now add this connection to the chain of cached connections */
444 lcp = store_get(sizeof(LDAP_CONNECTION));
445 lcp->host = (host == NULL)? NULL : string_copy(host);
448 lcp->password = NULL;
451 lcp->next = ldap_connections;
452 ldap_connections = lcp;
455 /* Found cached connection */
460 debug_printf("re-using cached connection to LDAP server %s%s\n",
464 /* Bind with the user/password supplied, or an anonymous bind if these values
465 are NULL, unless a cached connection is already bound with the same values. */
468 (lcp->user == NULL && user != NULL) ||
469 (lcp->user != NULL && user == NULL) ||
470 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
471 (lcp->password == NULL && password != NULL) ||
472 (lcp->password != NULL && password == NULL) ||
473 (lcp->password != NULL && password != NULL &&
474 Ustrcmp(lcp->password, password) != 0))
476 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
477 (lcp->bound)? "re-" : "", user, password);
478 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
481 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
482 "%s%s - ldap_bind() returned -1", host, porttext);
486 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
488 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
489 "%s%s - LDAP error: %s", host, porttext,
490 rc == -1 ? "result retrieval failed" : "timeout" );
495 rc = ldap_result2error( lcp->ld, result, 0 );
497 /* Invalid credentials when just checking credentials returns FAIL. This
498 stops any further servers being tried. */
500 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
503 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
505 goto RETURN_ERROR_NOMSG;
508 /* Otherwise we have a problem that doesn't stop further servers from being
511 if (rc != LDAP_SUCCESS)
513 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
514 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
518 /* Successful bind */
521 lcp->user = (user == NULL)? NULL : string_copy(user);
522 lcp->password = (password == NULL)? NULL : string_copy(password);
524 ldap_msgfree(result);
528 /* If we are just checking credentials, return OK. */
530 if (search_type == SEARCH_LDAP_AUTH)
532 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
536 /* Before doing the search, set the time and size limits (if given). Here again
537 the different implementations of LDAP have chosen to do things differently. */
539 #if defined(LDAP_OPT_SIZELIMIT)
540 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
541 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
543 lcp->ld->ld_sizelimit = sizelimit;
544 lcp->ld->ld_timelimit = timelimit;
547 /* Similarly for dereferencing aliases. Don't know if this is possible on
548 an LDAP library without LDAP_OPT_DEREF. */
550 #if defined(LDAP_OPT_DEREF)
551 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
554 /* Start the search on the server. */
556 DEBUG(D_lookup) debug_printf("Start search\n");
558 msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
563 *errmsg = string_sprintf("ldap search initiation failed");
567 /* Loop to pick up results as they come in, setting a timeout if one was
570 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
571 LDAP_RES_SEARCH_ENTRY)
575 DEBUG(D_lookup) debug_printf("ldap_result loop\n");
577 for(e = ldap_first_entry(lcp->ld, result);
579 e = ldap_next_entry(lcp->ld, e))
582 BOOL insert_space = FALSE;
584 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
586 rescount++; /* Count results */
588 /* Results for multiple entries values are separated by newlines. */
590 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
592 /* Get the DN from the last result. */
594 new_dn = US ldap_get_dn(lcp->ld, e);
599 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
601 #else /* OPENLDAP 1, UMich, Solaris */
609 /* If the data we want is actually the DN rather than any attribute values,
610 (an "ldapdn" search) add it to the data string. If there are multiple
611 entries, the DNs will be concatenated, but we test for this case below, as
612 for SEARCH_LDAP_SINGLE, and give an error. */
614 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
615 { /* condition, because of the else */
616 if (new_dn != NULL) /* below, that's for the first only */
618 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
620 attribute_found = TRUE;
624 /* Otherwise, loop through the entry, grabbing attribute values. If there's
625 only one attribute being retrieved, no attribute name is given, and the
626 result is not quoted. Multiple values are separated by (comma, space).
627 If more than one attribute is being retrieved, the data is given as a
628 sequence of name=value pairs, with the value always in quotes. If there are
629 multiple values, they are given within the quotes, comma separated. */
631 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
633 attr = US ldap_next_attribute(lcp->ld, e, ber))
637 /* Get array of values for this attribute. */
639 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
645 data = string_cat(data, &size, &ptr, US" ", 1);
648 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
649 data = string_cat(data, &size, &ptr, US"=\"", 2);
652 while (*values != NULL)
654 uschar *value = *values;
655 int len = Ustrlen(value);
657 DEBUG(D_lookup) debug_printf("LDAP attr loop %s:%s\n", attr, value);
659 if (values != firstval)
660 data = string_cat(data, &size, &ptr, US", ", 2);
662 /* For multiple attributes, the data is in quotes. We must escape
663 internal quotes, backslashes, newlines. */
668 for (j = 0; j < len; j++)
670 if (value[j] == '\n')
671 data = string_cat(data, &size, &ptr, US"\\n", 2);
674 if (value[j] == '\"' || value[j] == '\\')
675 data = string_cat(data, &size, &ptr, US"\\", 1);
676 data = string_cat(data, &size, &ptr, value+j, 1);
681 /* For single attributes, copy the value verbatim */
683 else data = string_cat(data, &size, &ptr, value, len);
685 /* Move on to the next value */
688 attribute_found = TRUE;
691 /* Closing quote at the end of the data for a named attribute. */
694 data = string_cat(data, &size, &ptr, US"\"", 1);
696 /* Free the values */
698 ldap_value_free(CSS firstval);
702 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
704 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
705 to be freed. UMich LDAP stores them in static storage and does not require
710 } /* End "for" loop for extracting attributes from an entry */
711 } /* End "for" loop for extracting entries from a result */
713 /* Free the result */
715 ldap_msgfree(result);
717 } /* End "while" loop for multiple results */
719 /* Terminate the dynamic string that we have built and reclaim unused store */
724 store_reset(data + ptr + 1);
727 /* Copy the last dn into eldap_dn */
731 eldap_dn = string_copy(dn);
732 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
734 #else /* OPENLDAP 1, UMich, Solaris */
739 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
743 *errmsg = US"ldap_result timed out";
747 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
748 provide you with a message". Other error states seem to exist where
749 ldap_result() didn't give us any message from the server at all, leaving result
750 set to NULL. Apparently, "the error parameters of the LDAP session handle will
751 be set accordingly". That's the best we can do to retrieve an error status; we
752 can't use functions like ldap_result2error because they parse a message from
753 the server, which we didn't get.
755 Annoyingly, the different implementations of LDAP have gone for different
756 methods of handling error codes and generating error messages. */
758 if (rc == -1 || result == NULL)
761 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
763 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
764 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
765 *errmsg = string_sprintf("ldap_result failed: %d, %s",
766 err, ldap_err2string(err));
768 #elif defined LDAP_LIB_NETSCAPE
769 /* Dubious (surely 'matched' is spurious here?) */
770 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
771 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
773 #else /* UMich LDAP aka OpenLDAP 1.x */
774 *errmsg = string_sprintf("ldap_result failed: %d, %s",
775 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
781 /* A return code that isn't -1 doesn't necessarily mean there were no problems
782 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
783 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. */
785 if (rc != LDAP_RES_SEARCH_RESULT && rc != LDAP_RES_SEARCH_REFERENCE)
787 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
791 /* We have a result message from the server. This doesn't yet mean all is well.
792 We need to parse the message to find out exactly what's happened. */
794 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
796 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
797 CSS &error2, NULL, NULL, 0);
798 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
799 if (ldap_parse_rc < 0 &&
800 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED ||
801 ldap_rc != LDAP_RES_SEARCH_REFERENCE))
803 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
806 error1 = US ldap_err2string(rc);
808 #elif defined LDAP_LIB_NETSCAPE
809 /* Dubious (it doesn't reference 'result' at all!) */
810 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
812 #else /* UMich LDAP aka OpenLDAP 1.x */
813 rc = ldap_result2error(lcp->ld, result, 0);
814 error1 = ldap_err2string(rc);
815 error2 = lcp->ld->ld_error;
816 matched = lcp->ld->ld_matched;
819 /* Process the status as follows:
821 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
822 truncated result list.
824 (2) The range of errors defined by LDAP_NAME_ERROR generally mean "that
825 object does not, or cannot, exist in the database". For those cases we
828 (3) All other non-successes here are treated as some kind of problem with
829 the lookup, so return DEFER (which is the default in error_yield).
832 DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
833 rc, ldap_err2string(rc));
835 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED)
837 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
839 (error1 != NULL)? error1 : US"",
840 (error2 != NULL && error2[0] != 0)? US"/" : US"",
841 (error2 != NULL)? error2 : US"",
842 (matched != NULL && matched[0] != 0)? US"/" : US"",
843 (matched != NULL)? matched : US"");
845 #if defined LDAP_NAME_ERROR
846 if (LDAP_NAME_ERROR(rc))
847 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
850 if (rc == LDAP_NO_SUCH_OBJECT)
854 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
860 /* The search succeeded. Check if we have too many results */
862 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
864 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
865 "(filter not specific enough?)", rescount);
866 goto RETURN_ERROR_BREAK;
869 /* Check if we have too few (zero) entries */
873 *errmsg = string_sprintf("LDAP search: no results");
875 goto RETURN_ERROR_BREAK;
878 /* If an entry was found, but it had no attributes, we behave as if no entries
879 were found, that is, the lookup failed. */
881 if (!attribute_found)
883 *errmsg = US"LDAP search: found no attributes";
888 /* Otherwise, it's all worked */
890 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
894 if (result != NULL) ldap_msgfree(result);
895 ldap_free_urldesc(ludp);
904 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
907 if (result != NULL) ldap_msgfree(result);
908 if (ludp != NULL) ldap_free_urldesc(ludp);
910 #if defined LDAP_LIB_OPENLDAP2
911 if (error2 != NULL) ldap_memfree(error2);
912 if (matched != NULL) ldap_memfree(matched);
920 /*************************************************
921 * Internal search control function *
922 *************************************************/
924 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
925 and eldapm_find() with a difference in the "search_type" argument. It controls
926 calls to perform_ldap_search() which actually does the work. We call that
927 repeatedly for certain types of defer in the case when the URL contains no host
928 name and eldap_default_servers is set to a list of servers to try. This gives
929 more control than just passing over a list of hosts to ldap_open() because it
930 handles other kinds of defer as well as just a failure to open. Note that the
931 URL is defined to contain either zero or one "hostport" only.
933 Parameter data in addition to the URL can be passed as preceding text in the
934 string, as items of the form XXX=yyy. The URL itself can be detected because it
935 must begin "ldapx://", where x is empty, s, or i.
938 ldap_url the URL to be looked up, optionally preceded by other parameter
940 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
941 SEARCH_LDAP_SINGLE allows values from one entry only
942 SEARCH_LDAP_DN gets the DN from one entry
943 res set to point at the result
944 errmsg set to point a message if result is not OK
946 Returns: OK or FAIL or DEFER
950 control_ldap_search(uschar *ldap_url, int search_type, uschar **res,
953 BOOL defer_break = FALSE;
954 int timelimit = LDAP_NO_LIMIT;
955 int sizelimit = LDAP_NO_LIMIT;
957 int dereference = LDAP_DEREF_NEVER;
959 uschar *url = ldap_url;
962 uschar *password = NULL;
963 uschar *server, *list;
966 while (isspace(*url)) url++;
968 /* Until the string begins "ldap", search for the other parameter settings that
969 are recognized. They are of the form NAME=VALUE, with the value being
970 optionally double-quoted. There must still be a space after it, however. No
971 NAME has the value "ldap". */
973 while (strncmpic(url, US"ldap", 4) != 0)
976 while (*url != 0 && *url != '=') url++;
981 namelen = ++url - name;
982 value = string_dequote(&url);
985 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
986 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
987 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
988 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
989 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
990 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
992 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
994 #ifdef LDAP_OPT_DEREF
995 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
997 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
998 else if (strcmpic(value, US"searching") == 0)
999 dereference = LDAP_DEREF_SEARCHING;
1000 else if (strcmpic(value, US"finding") == 0)
1001 dereference = LDAP_DEREF_FINDING;
1002 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1005 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1007 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1008 "library - cannot use \"dereference\"");
1009 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1018 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1020 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1023 while (isspace(*url)) url++;
1027 *errmsg = US"malformed parameter setting precedes LDAP URL";
1028 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1032 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1033 but it seems that not all behave like this. The DN for the user is often the
1034 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1035 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1036 far too complicated. */
1042 for (s = user; *s != 0; s++)
1045 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1050 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1051 ((d >= 'a')? (10 + d - 'a') : d - '0');
1060 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1061 "dereference=%d\n", user, password, sizelimit, timelimit, tcplimit,
1064 /* If the request is just to check authentication, some credentials must
1065 be given. The password must not be empty because LDAP binds with an empty
1066 password are considered anonymous, and will succeed on most installations. */
1068 if (search_type == SEARCH_LDAP_AUTH)
1070 if (user == NULL || password == NULL)
1072 *errmsg = US"ldapauth lookups must specify the username and password";
1075 if (password[0] == 0)
1077 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1082 /* Check for valid ldap url starters */
1085 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1086 if (Ustrncmp(p, "://", 3) != 0)
1088 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1089 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1090 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1094 /* No default servers, or URL contains a server name: just one attempt */
1096 if (eldap_default_servers == NULL || p[3] != '/')
1098 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1099 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference);
1102 /* Loop through the default servers until OK or FAIL */
1104 list = eldap_default_servers;
1105 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1109 uschar *colon = Ustrchr(server, ':');
1113 port = Uatoi(colon+1);
1115 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1116 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference);
1117 if (rc != DEFER || defer_break) return rc;
1125 /*************************************************
1126 * Find entry point *
1127 *************************************************/
1129 /* See local README for interface description. The different kinds of search
1130 are handled by a common function, with a flag to differentiate between them.
1131 The handle and filename arguments are not used. */
1134 eldap_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1135 uschar **result, uschar **errmsg, BOOL *do_cache)
1137 /* Keep picky compilers happy */
1138 do_cache = do_cache;
1139 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1143 eldapm_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1144 uschar **result, uschar **errmsg, BOOL *do_cache)
1146 /* Keep picky compilers happy */
1147 do_cache = do_cache;
1148 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1152 eldapdn_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1153 uschar **result, uschar **errmsg, BOOL *do_cache)
1155 /* Keep picky compilers happy */
1156 do_cache = do_cache;
1157 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1161 eldapauth_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1162 uschar **result, uschar **errmsg, BOOL *do_cache)
1164 /* Keep picky compilers happy */
1165 do_cache = do_cache;
1166 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1171 /*************************************************
1172 * Open entry point *
1173 *************************************************/
1175 /* See local README for interface description. */
1178 eldap_open(uschar *filename, uschar **errmsg)
1180 return (void *)(1); /* Just return something non-null */
1185 /*************************************************
1186 * Tidy entry point *
1187 *************************************************/
1189 /* See local README for interface description.
1190 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1195 LDAP_CONNECTION *lcp = NULL;
1198 while ((lcp = ldap_connections) != NULL)
1200 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1202 ldap_unbind(lcp->ld);
1203 ldap_connections = lcp->next;
1209 /*************************************************
1210 * Quote entry point *
1211 *************************************************/
1213 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1214 quoting have to be done: LDAP quoting, and URL quoting. The current
1215 specification is the result of a suggestion by Brian Candler. It recognizes
1218 (1) For text that appears in a search filter, the following escapes are
1219 required (see RFC 2254):
1227 Then the entire filter text must be URL-escaped. This kind of quoting is
1228 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1229 in the input string, because that's a terminator.
1231 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1235 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1236 must be escaped, as must a leading #. Then the string must be URL-quoted.
1237 This type of quoting is implemented by ${quote_ldap_dn:....}.
1239 For URL quoting, the only characters that need not be quoted are the
1244 All the others must be hexified and preceded by %. This includes the
1245 backslashes used for LDAP quoting.
1247 For a DN that is given in the USER parameter for authentication, we need the
1248 same initial quoting as (2) but in this case, the result must NOT be
1249 URL-escaped, because it isn't a URL. The way this is handled is by
1250 de-URL-quoting the text when processing the USER parameter in
1251 control_ldap_search() above. That means that the same quote operator can be
1252 used. This has the additional advantage that spaces in the DN won't cause
1253 parsing problems. For example:
1255 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1257 should be safe if there are spaces in $1.
1261 s the string to be quoted
1262 opt additional option text or NULL if none
1263 only "dn" is recognized
1265 Returns: the processed string or NULL for a bad option
1270 /* The characters in this string, together with alphanumerics, never need
1271 quoting in any way. */
1273 #define ALWAYS_LITERAL "!$'-._"
1275 /* The special characters in this string do not need to be URL-quoted. The set
1276 is a bit larger than the general literals. */
1278 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1280 /* The following macros define the characters that are quoted by quote_ldap and
1281 quote_ldap_dn, respectively. */
1283 #define LDAP_QUOTE "*()\\"
1284 #define LDAP_DN_QUOTE ",+\"\\<>;"
1289 eldap_quote(uschar *s, uschar *opt)
1298 /* Test for a DN quotation. */
1302 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1306 /* Compute how much extra store we need for the string. This doesn't have to be
1307 exact as long as it isn't an underestimate. The worst case is the addition of 5
1308 extra bytes for a single character. This occurs for certain characters in DNs,
1309 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1310 possibly escaped character. The really fast way would be just to test for
1311 non-alphanumerics, but it is probably better to spot a few others that are
1312 never escaped, because if there are no specials at all, we can avoid copying
1315 while ((c = *t++) != 0)
1318 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1320 if (count == 0) return s;
1322 /* Get sufficient store to hold the quoted string */
1324 t = quoted = store_get(len + count + 1);
1326 /* Handle plain quote_ldap */
1330 while ((c = *s++) != 0)
1334 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1336 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1340 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1342 sprintf(CS t, "%%%02X", c);
1347 *t++ = c; /* unquoted character */
1351 /* Handle quote_ldap_dn */
1355 uschar *ss = s + len;
1357 /* Find the last char before any trailing spaces */
1359 while (ss > s && ss[-1] == ' ') ss--;
1361 /* Quote leading spaces and sharps */
1365 if (*s != ' ' && *s != '#') break;
1366 sprintf(CS t, "%%5C%%%02X", *s);
1370 /* Handle the rest of the string, up to the trailing spaces */
1377 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1379 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1380 t += 3; /* fall through to check URL */
1382 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1384 sprintf(CS t, "%%%02X", c);
1389 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1392 /* Handle the trailing spaces */
1396 Ustrncpy(t, "%5C%20", 6);
1401 /* Terminate the new string and return */
1407 #endif /* LOOKUP_LDAP */
1409 /* End of lookups/ldap.c */