1 /* $Cambridge: exim/src/src/lookups/ldap.c,v 1.15 2009/11/16 19:50:38 nm4 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2009 */
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"
20 /* Include LDAP headers. The code below uses some "old" LDAP interfaces that
21 are deprecated in OpenLDAP. I don't know their status in other LDAP
22 implementations. LDAP_DEPRECATED causes their prototypes to be defined in
25 #define LDAP_DEPRECATED 1
31 /* Annoyingly, the different LDAP libraries handle errors in different ways,
32 and some other things too. There doesn't seem to be an automatic way of
33 distinguishing between them. Local/Makefile should contain a setting of
34 LDAP_LIB_TYPE, which in turn causes appropriate macros to be defined for the
35 different kinds. Those that matter are:
38 LDAP_LIB_SOLARIS with synonym LDAP_LIB_SOLARIS7
41 These others may be defined, but are in fact the default, so are not tested:
47 #if defined(LDAP_LIB_SOLARIS7) && ! defined(LDAP_LIB_SOLARIS)
48 #define LDAP_LIB_SOLARIS
52 /* Just in case LDAP_NO_LIMIT is not defined by some of these libraries. */
55 #define LDAP_NO_LIMIT 0
59 /* Just in case LDAP_DEREF_NEVER is not defined */
61 #ifndef LDAP_DEREF_NEVER
62 #define LDAP_DEREF_NEVER 0
66 /* Four types of LDAP search are implemented */
68 #define SEARCH_LDAP_MULTIPLE 0 /* Get attributes from multiple entries */
69 #define SEARCH_LDAP_SINGLE 1 /* Get attributes from one entry only */
70 #define SEARCH_LDAP_DN 2 /* Get just the DN from one entry */
71 #define SEARCH_LDAP_AUTH 3 /* Just checking for authentication */
73 /* In all 4 cases, the DN is left in $ldap_dn (which post-dates the
74 SEARCH_LDAP_DN lookup). */
77 /* Structure and anchor for caching connections. */
79 typedef struct ldap_connection {
80 struct ldap_connection *next;
89 static LDAP_CONNECTION *ldap_connections = NULL;
93 /*************************************************
94 * Internal search function *
95 *************************************************/
97 /* This is the function that actually does the work. It is called (indirectly
98 via control_ldap_search) from eldap_find(), eldapauth_find(), eldapdn_find(),
99 and eldapm_find(), with a difference in the "search_type" argument.
101 The case of eldapauth_find() is special in that all it does is do
102 authentication, returning OK or FAIL as appropriate. This isn't used as a
103 lookup. Instead, it is called from expand.c as an expansion condition test.
105 The DN from a successful lookup is placed in $ldap_dn. This feature postdates
106 the provision of the SEARCH_LDAP_DN facility for returning just the DN as the
110 ldap_url the URL to be looked up
111 server server host name, when URL contains none
112 s_port server port, used when URL contains no name
113 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
114 SEARCH_LDAP_SINGLE allows values from one entry only
115 SEARCH_LDAP_DN gets the DN from one entry
116 res set to point at the result (not used for ldapauth)
117 errmsg set to point a message if result is not OK
118 defer_break set TRUE if no more servers to be tried after a DEFER
119 user user name for authentication, or NULL
120 password password for authentication, or NULL
121 sizelimit max number of entries returned, or 0 for no limit
122 timelimit max time to wait, or 0 for no limit
123 tcplimit max time for network activity, e.g. connect, or 0 for OS default
124 deference the dereference option, which is one of
125 LDAP_DEREF_{NEVER,SEARCHING,FINDING,ALWAYS}
126 referrals the referral option, which is LDAP_OPT_ON or LDAP_OPT_OFF
128 Returns: OK or FAIL or DEFER
129 FAIL is given only if a lookup was performed successfully, but
134 perform_ldap_search(uschar *ldap_url, uschar *server, int s_port, int search_type,
135 uschar **res, uschar **errmsg, BOOL *defer_break, uschar *user, uschar *password,
136 int sizelimit, int timelimit, int tcplimit, int dereference, void *referrals)
138 LDAPURLDesc *ludp = NULL;
139 LDAPMessage *result = NULL;
141 LDAP_CONNECTION *lcp;
143 struct timeval timeout;
144 struct timeval *timeoutptr = NULL;
155 uschar *error1 = NULL; /* string representation of errcode (static) */
156 uschar *error2 = NULL; /* error message from the server */
157 uschar *matched = NULL; /* partially matched DN */
160 int error_yield = DEFER;
162 int rc, ldap_rc, ldap_parse_rc;
167 BOOL attribute_found = FALSE;
171 debug_printf("perform_ldap_search: ldap%s URL = \"%s\" server=%s port=%d "
172 "sizelimit=%d timelimit=%d tcplimit=%d\n",
173 (search_type == SEARCH_LDAP_MULTIPLE)? "m" :
174 (search_type == SEARCH_LDAP_DN)? "dn" :
175 (search_type == SEARCH_LDAP_AUTH)? "auth" : "",
176 ldap_url, server, s_port, sizelimit, timelimit, tcplimit);
178 /* Check if LDAP thinks the URL is a valid LDAP URL. We assume that if the LDAP
179 library that is in use doesn't recognize, say, "ldapi", it will barf here. */
181 if (!ldap_is_ldap_url(CS ldap_url))
183 *errmsg = string_sprintf("ldap_is_ldap_url: not an LDAP url \"%s\"\n",
185 goto RETURN_ERROR_BREAK;
190 if ((rc = ldap_url_parse(CS ldap_url, &ludp)) != 0)
192 *errmsg = string_sprintf("ldap_url_parse: (error %d) parsing \"%s\"\n", rc,
194 goto RETURN_ERROR_BREAK;
197 /* If the host name is empty, take it from the separate argument, if one is
198 given. OpenLDAP 2.0.6 sets an unset hostname to "" rather than empty, but
199 expects NULL later in ldap_init() to mean "default", annoyingly. In OpenLDAP
200 2.0.11 this has changed (it uses NULL). */
202 if ((ludp->lud_host == NULL || ludp->lud_host[0] == 0) && server != NULL)
209 host = US ludp->lud_host;
210 if (host != NULL && host[0] == 0) host = NULL;
211 port = ludp->lud_port;
214 DEBUG(D_lookup) debug_printf("after ldap_url_parse: host=%s port=%d\n",
217 if (port == 0) port = LDAP_PORT; /* Default if none given */
218 sprintf(CS porttext, ":%d", port); /* For messages */
220 /* If the "host name" is actually a path, we are going to connect using a Unix
221 socket, regardless of whether "ldapi" was actually specified or not. This means
222 that a Unix socket can be declared in eldap_default_servers, and "traditional"
223 LDAP queries using just "ldap" can be used ("ldaps" is similarly overridden).
224 The path may start with "/" or it may already be escaped as "%2F" if it was
225 actually declared that way in eldap_default_servers. (I did it that way the
226 first time.) If the host name is not a path, the use of "ldapi" causes an
227 error, except in the default case. (But lud_scheme doesn't seem to exist in
232 if ((host[0] == '/' || Ustrncmp(host, "%2F", 3) == 0))
235 porttext[0] = 0; /* Remove port from messages */
238 #if defined LDAP_LIB_OPENLDAP2
239 else if (strncmp(ludp->lud_scheme, "ldapi", 5) == 0)
241 *errmsg = string_sprintf("ldapi requires an absolute path (\"%s\" given)",
248 /* Count the attributes; we need this later to tell us how to format results */
250 for (attrp = USS ludp->lud_attrs; attrp != NULL && *attrp != NULL; attrp++)
253 /* See if we can find a cached connection to this host. The port is not
254 relevant for ldapi. The host name pointer is set to NULL if no host was given
255 (implying the library default), rather than to the empty string. Note that in
256 this case, there is no difference between ldap and ldapi. */
258 for (lcp = ldap_connections; lcp != NULL; lcp = lcp->next)
260 if ((host == NULL) != (lcp->host == NULL) ||
261 (host != NULL && strcmpic(lcp->host, host) != 0))
263 if (ldapi || port == lcp->port) break;
266 /* Use this network timeout in any requests. */
270 timeout.tv_sec = tcplimit;
272 timeoutptr = &timeout;
275 /* If no cached connection found, we must open a connection to the server. If
276 the server name is actually an absolute path, we set ldapi=TRUE above. This
277 requests connection via a Unix socket. However, as far as I know, only OpenLDAP
278 supports the use of sockets, and the use of ldap_initialize(). */
285 /* --------------------------- OpenLDAP ------------------------ */
287 /* There seems to be a preference under OpenLDAP for ldap_initialize()
288 instead of ldap_init(), though I have as yet been unable to find
289 documentation that says this. (OpenLDAP documentation is sparse to
290 non-existent). So we handle OpenLDAP differently here. Also, support for
291 ldapi seems to be OpenLDAP-only at present. */
293 #ifdef LDAP_LIB_OPENLDAP2
295 /* We now need an empty string for the default host. Get some store in which
296 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
297 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
298 than the host name + "ldaps:///" plus : and a port number, say 20 + the
299 length of the host name. What we get should accommodate both, easily. */
301 uschar *shost = (host == NULL)? US"" : host;
302 uschar *init_url = store_get(20 + 3 * Ustrlen(shost));
305 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
306 contain the path name, with slashes escaped as %2F. */
311 init_ptr = init_url + 8;
312 Ustrcpy(init_url, "ldapi://");
313 while ((ch = *shost++) != 0)
317 Ustrncpy(init_ptr, "%2F", 3);
320 else *init_ptr++ = ch;
325 /* This is not an ldapi call. Just build a URI with the protocol type, host
330 init_ptr = Ustrchr(ldap_url, '/');
331 Ustrncpy(init_url, ldap_url, init_ptr - ldap_url);
332 init_ptr = init_url + (init_ptr - ldap_url);
333 sprintf(CS init_ptr, "//%s:%d/", shost, port);
336 /* Call ldap_initialize() and check the result */
338 DEBUG(D_lookup) debug_printf("ldap_initialize with URL %s\n", init_url);
339 rc = ldap_initialize(&ld, CS init_url);
340 if (rc != LDAP_SUCCESS)
342 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
346 store_reset(init_url); /* Might as well save memory when we can */
349 /* ------------------------- Not OpenLDAP ---------------------- */
351 /* For libraries other than OpenLDAP, use ldap_init(). */
353 #else /* LDAP_LIB_OPENLDAP2 */
354 ld = ldap_init(CS host, port);
355 #endif /* LDAP_LIB_OPENLDAP2 */
357 /* -------------------------------------------------------------- */
360 /* Handle failure to initialize */
364 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
365 host, porttext, strerror(errno));
369 /* Set the TCP connect time limit if available. This is something that is
370 in Netscape SDK v4.1; I don't know about other libraries. */
372 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
375 int timeout1000 = tcplimit*1000;
376 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
380 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
381 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)¬imeout);
385 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
387 #ifdef LDAP_OPT_NETWORK_TIMEOUT
389 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
392 /* I could not get TLS to work until I set the version to 3. That version
393 seems to be the default nowadays. The RFC is dated 1997, so I would hope
394 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
395 been set, go for v3 if we can. */
397 if (eldap_version < 0)
400 eldap_version = LDAP_VERSION3;
406 #ifdef LDAP_OPT_PROTOCOL_VERSION
407 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
410 DEBUG(D_lookup) debug_printf("initialized for LDAP (v%d) server %s%s\n",
411 eldap_version, host, porttext);
413 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
414 for "ldaps" and soft otherwise. */
416 #ifdef LDAP_OPT_X_TLS
420 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
422 tls_option = LDAP_OPT_X_TLS_HARD;
423 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_HARD set\n");
427 tls_option = LDAP_OPT_X_TLS_TRY;
428 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_TRY set\n");
430 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
432 #endif /* LDAP_OPT_X_TLS */
434 /* Now add this connection to the chain of cached connections */
436 lcp = store_get(sizeof(LDAP_CONNECTION));
437 lcp->host = (host == NULL)? NULL : string_copy(host);
440 lcp->password = NULL;
443 lcp->next = ldap_connections;
444 ldap_connections = lcp;
447 /* Found cached connection */
452 debug_printf("re-using cached connection to LDAP server %s%s\n",
456 /* Bind with the user/password supplied, or an anonymous bind if these values
457 are NULL, unless a cached connection is already bound with the same values. */
460 (lcp->user == NULL && user != NULL) ||
461 (lcp->user != NULL && user == NULL) ||
462 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
463 (lcp->password == NULL && password != NULL) ||
464 (lcp->password != NULL && password == NULL) ||
465 (lcp->password != NULL && password != NULL &&
466 Ustrcmp(lcp->password, password) != 0))
468 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
469 (lcp->bound)? "re-" : "", user, password);
470 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
473 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
474 "%s%s - ldap_bind() returned -1", host, porttext);
478 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
480 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
481 "%s%s - LDAP error: %s", host, porttext,
482 rc == -1 ? "result retrieval failed" : "timeout" );
487 rc = ldap_result2error( lcp->ld, result, 0 );
489 /* Invalid credentials when just checking credentials returns FAIL. This
490 stops any further servers being tried. */
492 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
495 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
497 goto RETURN_ERROR_NOMSG;
500 /* Otherwise we have a problem that doesn't stop further servers from being
503 if (rc != LDAP_SUCCESS)
505 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
506 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
510 /* Successful bind */
513 lcp->user = (user == NULL)? NULL : string_copy(user);
514 lcp->password = (password == NULL)? NULL : string_copy(password);
516 ldap_msgfree(result);
520 /* If we are just checking credentials, return OK. */
522 if (search_type == SEARCH_LDAP_AUTH)
524 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
528 /* Before doing the search, set the time and size limits (if given). Here again
529 the different implementations of LDAP have chosen to do things differently. */
531 #if defined(LDAP_OPT_SIZELIMIT)
532 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
533 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
535 lcp->ld->ld_sizelimit = sizelimit;
536 lcp->ld->ld_timelimit = timelimit;
539 /* Similarly for dereferencing aliases. Don't know if this is possible on
540 an LDAP library without LDAP_OPT_DEREF. */
542 #if defined(LDAP_OPT_DEREF)
543 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
546 /* Similarly for the referral setting; should the library follow referrals that
547 the LDAP server returns? The conditional is just in case someone uses a library
550 #if defined(LDAP_OPT_REFERRALS)
551 ldap_set_option(lcp->ld, LDAP_OPT_REFERRALS, referrals);
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 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
565 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
566 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
567 ldap_err2string(err));
570 *errmsg = string_sprintf("ldap_search failed");
576 /* Loop to pick up results as they come in, setting a timeout if one was
579 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
580 LDAP_RES_SEARCH_ENTRY)
584 DEBUG(D_lookup) debug_printf("ldap_result loop\n");
586 for(e = ldap_first_entry(lcp->ld, result);
588 e = ldap_next_entry(lcp->ld, e))
591 BOOL insert_space = FALSE;
593 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
595 rescount++; /* Count results */
597 /* Results for multiple entries values are separated by newlines. */
599 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
601 /* Get the DN from the last result. */
603 new_dn = US ldap_get_dn(lcp->ld, e);
608 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
610 #else /* OPENLDAP 1, UMich, Solaris */
618 /* If the data we want is actually the DN rather than any attribute values,
619 (an "ldapdn" search) add it to the data string. If there are multiple
620 entries, the DNs will be concatenated, but we test for this case below, as
621 for SEARCH_LDAP_SINGLE, and give an error. */
623 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
624 { /* condition, because of the else */
625 if (new_dn != NULL) /* below, that's for the first only */
627 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
629 attribute_found = TRUE;
633 /* Otherwise, loop through the entry, grabbing attribute values. If there's
634 only one attribute being retrieved, no attribute name is given, and the
635 result is not quoted. Multiple values are separated by (comma, space).
636 If more than one attribute is being retrieved, the data is given as a
637 sequence of name=value pairs, with the value always in quotes. If there are
638 multiple values, they are given within the quotes, comma separated. */
640 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
642 attr = US ldap_next_attribute(lcp->ld, e, ber))
646 /* Get array of values for this attribute. */
648 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
654 data = string_cat(data, &size, &ptr, US" ", 1);
657 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
658 data = string_cat(data, &size, &ptr, US"=\"", 2);
661 while (*values != NULL)
663 uschar *value = *values;
664 int len = Ustrlen(value);
666 DEBUG(D_lookup) debug_printf("LDAP attr loop %s:%s\n", attr, value);
668 if (values != firstval)
669 data = string_cat(data, &size, &ptr, US", ", 2);
671 /* For multiple attributes, the data is in quotes. We must escape
672 internal quotes, backslashes, newlines. */
677 for (j = 0; j < len; j++)
679 if (value[j] == '\n')
680 data = string_cat(data, &size, &ptr, US"\\n", 2);
683 if (value[j] == '\"' || value[j] == '\\')
684 data = string_cat(data, &size, &ptr, US"\\", 1);
685 data = string_cat(data, &size, &ptr, value+j, 1);
690 /* For single attributes, copy the value verbatim */
692 else data = string_cat(data, &size, &ptr, value, len);
694 /* Move on to the next value */
697 attribute_found = TRUE;
700 /* Closing quote at the end of the data for a named attribute. */
703 data = string_cat(data, &size, &ptr, US"\"", 1);
705 /* Free the values */
707 ldap_value_free(CSS firstval);
711 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
713 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
714 to be freed. UMich LDAP stores them in static storage and does not require
719 } /* End "for" loop for extracting attributes from an entry */
720 } /* End "for" loop for extracting entries from a result */
722 /* Free the result */
724 ldap_msgfree(result);
726 } /* End "while" loop for multiple results */
728 /* Terminate the dynamic string that we have built and reclaim unused store */
733 store_reset(data + ptr + 1);
736 /* Copy the last dn into eldap_dn */
740 eldap_dn = string_copy(dn);
741 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
743 #else /* OPENLDAP 1, UMich, Solaris */
748 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
752 *errmsg = US"ldap_result timed out";
756 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
757 provide you with a message". Other error states seem to exist where
758 ldap_result() didn't give us any message from the server at all, leaving result
759 set to NULL. Apparently, "the error parameters of the LDAP session handle will
760 be set accordingly". That's the best we can do to retrieve an error status; we
761 can't use functions like ldap_result2error because they parse a message from
762 the server, which we didn't get.
764 Annoyingly, the different implementations of LDAP have gone for different
765 methods of handling error codes and generating error messages. */
767 if (rc == -1 || result == NULL)
770 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
772 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
773 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
774 *errmsg = string_sprintf("ldap_result failed: %d, %s",
775 err, ldap_err2string(err));
777 #elif defined LDAP_LIB_NETSCAPE
778 /* Dubious (surely 'matched' is spurious here?) */
779 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
780 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
782 #else /* UMich LDAP aka OpenLDAP 1.x */
783 *errmsg = string_sprintf("ldap_result failed: %d, %s",
784 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
790 /* A return code that isn't -1 doesn't necessarily mean there were no problems
791 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
792 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
793 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
794 we don't provide that functionality when we can't. :-) */
796 if (rc != LDAP_RES_SEARCH_RESULT
797 #ifdef LDAP_RES_SEARCH_REFERENCE
798 && rc != LDAP_RES_SEARCH_REFERENCE
802 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
806 /* We have a result message from the server. This doesn't yet mean all is well.
807 We need to parse the message to find out exactly what's happened. */
809 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
811 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
812 CSS &error2, NULL, NULL, 0);
813 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
814 if (ldap_parse_rc < 0 &&
815 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
816 #ifdef LDAP_RES_SEARCH_REFERENCE
817 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
821 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
824 error1 = US ldap_err2string(rc);
826 #elif defined LDAP_LIB_NETSCAPE
827 /* Dubious (it doesn't reference 'result' at all!) */
828 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
830 #else /* UMich LDAP aka OpenLDAP 1.x */
831 rc = ldap_result2error(lcp->ld, result, 0);
832 error1 = ldap_err2string(rc);
833 error2 = lcp->ld->ld_error;
834 matched = lcp->ld->ld_matched;
837 /* Process the status as follows:
839 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
840 truncated result list.
842 (2) If we get LDAP_RES_SEARCH_REFERENCE, also just carry on. This was a
843 submitted patch that is reported to "do the right thing" with Solaris
844 LDAP libraries. (The problem it addresses apparently does not occur with
847 (3) The range of errors defined by LDAP_NAME_ERROR generally mean "that
848 object does not, or cannot, exist in the database". For those cases we
851 (4) All other non-successes here are treated as some kind of problem with
852 the lookup, so return DEFER (which is the default in error_yield).
855 DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
856 rc, ldap_err2string(rc));
858 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED
859 #ifdef LDAP_RES_SEARCH_REFERENCE
860 && rc != LDAP_RES_SEARCH_REFERENCE
864 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
866 (error1 != NULL)? error1 : US"",
867 (error2 != NULL && error2[0] != 0)? US"/" : US"",
868 (error2 != NULL)? error2 : US"",
869 (matched != NULL && matched[0] != 0)? US"/" : US"",
870 (matched != NULL)? matched : US"");
872 #if defined LDAP_NAME_ERROR
873 if (LDAP_NAME_ERROR(rc))
874 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
877 if (rc == LDAP_NO_SUCH_OBJECT)
881 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
887 /* The search succeeded. Check if we have too many results */
889 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
891 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
892 "(filter not specific enough?)", rescount);
893 goto RETURN_ERROR_BREAK;
896 /* Check if we have too few (zero) entries */
900 *errmsg = string_sprintf("LDAP search: no results");
902 goto RETURN_ERROR_BREAK;
905 /* If an entry was found, but it had no attributes, we behave as if no entries
906 were found, that is, the lookup failed. */
908 if (!attribute_found)
910 *errmsg = US"LDAP search: found no attributes";
915 /* Otherwise, it's all worked */
917 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
921 if (result != NULL) ldap_msgfree(result);
922 ldap_free_urldesc(ludp);
931 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
934 if (result != NULL) ldap_msgfree(result);
935 if (ludp != NULL) ldap_free_urldesc(ludp);
937 #if defined LDAP_LIB_OPENLDAP2
938 if (error2 != NULL) ldap_memfree(error2);
939 if (matched != NULL) ldap_memfree(matched);
947 /*************************************************
948 * Internal search control function *
949 *************************************************/
951 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
952 and eldapm_find() with a difference in the "search_type" argument. It controls
953 calls to perform_ldap_search() which actually does the work. We call that
954 repeatedly for certain types of defer in the case when the URL contains no host
955 name and eldap_default_servers is set to a list of servers to try. This gives
956 more control than just passing over a list of hosts to ldap_open() because it
957 handles other kinds of defer as well as just a failure to open. Note that the
958 URL is defined to contain either zero or one "hostport" only.
960 Parameter data in addition to the URL can be passed as preceding text in the
961 string, as items of the form XXX=yyy. The URL itself can be detected because it
962 must begin "ldapx://", where x is empty, s, or i.
965 ldap_url the URL to be looked up, optionally preceded by other parameter
967 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
968 SEARCH_LDAP_SINGLE allows values from one entry only
969 SEARCH_LDAP_DN gets the DN from one entry
970 res set to point at the result
971 errmsg set to point a message if result is not OK
973 Returns: OK or FAIL or DEFER
977 control_ldap_search(uschar *ldap_url, int search_type, uschar **res,
980 BOOL defer_break = FALSE;
981 int timelimit = LDAP_NO_LIMIT;
982 int sizelimit = LDAP_NO_LIMIT;
985 int dereference = LDAP_DEREF_NEVER;
986 void* referrals = LDAP_OPT_ON;
987 uschar *url = ldap_url;
990 uschar *password = NULL;
991 uschar *server, *list;
994 while (isspace(*url)) url++;
996 /* Until the string begins "ldap", search for the other parameter settings that
997 are recognized. They are of the form NAME=VALUE, with the value being
998 optionally double-quoted. There must still be a space after it, however. No
999 NAME has the value "ldap". */
1001 while (strncmpic(url, US"ldap", 4) != 0)
1004 while (*url != 0 && *url != '=') url++;
1009 namelen = ++url - name;
1010 value = string_dequote(&url);
1013 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1014 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1015 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1016 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1017 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1018 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1020 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1022 #ifdef LDAP_OPT_DEREF
1023 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1025 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1026 else if (strcmpic(value, US"searching") == 0)
1027 dereference = LDAP_DEREF_SEARCHING;
1028 else if (strcmpic(value, US"finding") == 0)
1029 dereference = LDAP_DEREF_FINDING;
1030 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1033 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1035 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1036 "library - cannot use \"dereference\"");
1037 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1042 #ifdef LDAP_OPT_REFERRALS
1043 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1045 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1046 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1049 *errmsg = string_sprintf("LDAP option REFERRALS is not \"follow\" "
1051 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1056 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1058 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1059 "library - cannot use \"referrals\"");
1060 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1068 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1070 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1073 while (isspace(*url)) url++;
1077 *errmsg = US"malformed parameter setting precedes LDAP URL";
1078 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1082 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1083 but it seems that not all behave like this. The DN for the user is often the
1084 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1085 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1086 far too complicated. */
1092 for (s = user; *s != 0; s++)
1095 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1100 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1101 ((d >= 'a')? (10 + d - 'a') : d - '0');
1110 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1111 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1112 tcplimit, dereference, (referrals == LDAP_OPT_ON)? "on" : "off");
1114 /* If the request is just to check authentication, some credentials must
1115 be given. The password must not be empty because LDAP binds with an empty
1116 password are considered anonymous, and will succeed on most installations. */
1118 if (search_type == SEARCH_LDAP_AUTH)
1120 if (user == NULL || password == NULL)
1122 *errmsg = US"ldapauth lookups must specify the username and password";
1125 if (password[0] == 0)
1127 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1132 /* Check for valid ldap url starters */
1135 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1136 if (Ustrncmp(p, "://", 3) != 0)
1138 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1139 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1140 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1144 /* No default servers, or URL contains a server name: just one attempt */
1146 if (eldap_default_servers == NULL || p[3] != '/')
1148 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1149 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1153 /* Loop through the default servers until OK or FAIL */
1155 list = eldap_default_servers;
1156 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1160 uschar *colon = Ustrchr(server, ':');
1164 port = Uatoi(colon+1);
1166 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1167 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1169 if (rc != DEFER || defer_break) return rc;
1177 /*************************************************
1178 * Find entry point *
1179 *************************************************/
1181 /* See local README for interface description. The different kinds of search
1182 are handled by a common function, with a flag to differentiate between them.
1183 The handle and filename arguments are not used. */
1186 eldap_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1187 uschar **result, uschar **errmsg, BOOL *do_cache)
1189 /* Keep picky compilers happy */
1190 do_cache = do_cache;
1191 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1195 eldapm_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1196 uschar **result, uschar **errmsg, BOOL *do_cache)
1198 /* Keep picky compilers happy */
1199 do_cache = do_cache;
1200 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1204 eldapdn_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1205 uschar **result, uschar **errmsg, BOOL *do_cache)
1207 /* Keep picky compilers happy */
1208 do_cache = do_cache;
1209 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1213 eldapauth_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1214 uschar **result, uschar **errmsg, BOOL *do_cache)
1216 /* Keep picky compilers happy */
1217 do_cache = do_cache;
1218 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1223 /*************************************************
1224 * Open entry point *
1225 *************************************************/
1227 /* See local README for interface description. */
1230 eldap_open(uschar *filename, uschar **errmsg)
1232 return (void *)(1); /* Just return something non-null */
1237 /*************************************************
1238 * Tidy entry point *
1239 *************************************************/
1241 /* See local README for interface description.
1242 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1247 LDAP_CONNECTION *lcp = NULL;
1250 while ((lcp = ldap_connections) != NULL)
1252 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1254 ldap_unbind(lcp->ld);
1255 ldap_connections = lcp->next;
1261 /*************************************************
1262 * Quote entry point *
1263 *************************************************/
1265 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1266 quoting have to be done: LDAP quoting, and URL quoting. The current
1267 specification is the result of a suggestion by Brian Candler. It recognizes
1270 (1) For text that appears in a search filter, the following escapes are
1271 required (see RFC 2254):
1279 Then the entire filter text must be URL-escaped. This kind of quoting is
1280 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1281 in the input string, because that's a terminator.
1283 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1287 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1288 must be escaped, as must a leading #. Then the string must be URL-quoted.
1289 This type of quoting is implemented by ${quote_ldap_dn:....}.
1291 For URL quoting, the only characters that need not be quoted are the
1296 All the others must be hexified and preceded by %. This includes the
1297 backslashes used for LDAP quoting.
1299 For a DN that is given in the USER parameter for authentication, we need the
1300 same initial quoting as (2) but in this case, the result must NOT be
1301 URL-escaped, because it isn't a URL. The way this is handled is by
1302 de-URL-quoting the text when processing the USER parameter in
1303 control_ldap_search() above. That means that the same quote operator can be
1304 used. This has the additional advantage that spaces in the DN won't cause
1305 parsing problems. For example:
1307 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1309 should be safe if there are spaces in $1.
1313 s the string to be quoted
1314 opt additional option text or NULL if none
1315 only "dn" is recognized
1317 Returns: the processed string or NULL for a bad option
1322 /* The characters in this string, together with alphanumerics, never need
1323 quoting in any way. */
1325 #define ALWAYS_LITERAL "!$'-._"
1327 /* The special characters in this string do not need to be URL-quoted. The set
1328 is a bit larger than the general literals. */
1330 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1332 /* The following macros define the characters that are quoted by quote_ldap and
1333 quote_ldap_dn, respectively. */
1335 #define LDAP_QUOTE "*()\\"
1336 #define LDAP_DN_QUOTE ",+\"\\<>;"
1341 eldap_quote(uschar *s, uschar *opt)
1350 /* Test for a DN quotation. */
1354 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1358 /* Compute how much extra store we need for the string. This doesn't have to be
1359 exact as long as it isn't an underestimate. The worst case is the addition of 5
1360 extra bytes for a single character. This occurs for certain characters in DNs,
1361 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1362 possibly escaped character. The really fast way would be just to test for
1363 non-alphanumerics, but it is probably better to spot a few others that are
1364 never escaped, because if there are no specials at all, we can avoid copying
1367 while ((c = *t++) != 0)
1370 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1372 if (count == 0) return s;
1374 /* Get sufficient store to hold the quoted string */
1376 t = quoted = store_get(len + count + 1);
1378 /* Handle plain quote_ldap */
1382 while ((c = *s++) != 0)
1386 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1388 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1392 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1394 sprintf(CS t, "%%%02X", c);
1399 *t++ = c; /* unquoted character */
1403 /* Handle quote_ldap_dn */
1407 uschar *ss = s + len;
1409 /* Find the last char before any trailing spaces */
1411 while (ss > s && ss[-1] == ' ') ss--;
1413 /* Quote leading spaces and sharps */
1417 if (*s != ' ' && *s != '#') break;
1418 sprintf(CS t, "%%5C%%%02X", *s);
1422 /* Handle the rest of the string, up to the trailing spaces */
1429 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1431 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1432 t += 3; /* fall through to check URL */
1434 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1436 sprintf(CS t, "%%%02X", c);
1441 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1444 /* Handle the trailing spaces */
1448 Ustrncpy(t, "%5C%20", 6);
1453 /* Terminate the new string and return */
1461 /*************************************************
1462 * Version reporting entry point *
1463 *************************************************/
1465 /* See local README for interface description. */
1467 #include "../version.h"
1470 ldap_version_report(FILE *f)
1473 fprintf(f, "Library version: LDAP: Exim version %s\n", EXIM_VERSION_STR);
1478 static lookup_info ldap_lookup_info = {
1479 US"ldap", /* lookup name */
1480 lookup_querystyle, /* query-style lookup */
1481 eldap_open, /* open function */
1482 NULL, /* check function */
1483 eldap_find, /* find function */
1484 NULL, /* no close function */
1485 eldap_tidy, /* tidy function */
1486 eldap_quote, /* quoting function */
1487 ldap_version_report /* version reporting */
1490 static lookup_info ldapdn_lookup_info = {
1491 US"ldapdn", /* lookup name */
1492 lookup_querystyle, /* query-style lookup */
1493 eldap_open, /* sic */ /* open function */
1494 NULL, /* check function */
1495 eldapdn_find, /* find function */
1496 NULL, /* no close function */
1497 eldap_tidy, /* sic */ /* tidy function */
1498 eldap_quote, /* sic */ /* quoting function */
1499 NULL /* no version reporting (redundant) */
1502 static lookup_info ldapm_lookup_info = {
1503 US"ldapm", /* lookup name */
1504 lookup_querystyle, /* query-style lookup */
1505 eldap_open, /* sic */ /* open function */
1506 NULL, /* check function */
1507 eldapm_find, /* find function */
1508 NULL, /* no close function */
1509 eldap_tidy, /* sic */ /* tidy function */
1510 eldap_quote, /* sic */ /* quoting function */
1511 NULL /* no version reporting (redundant) */
1515 #define ldap_lookup_module_info _lookup_module_info
1518 static lookup_info *_lookup_list[] = { &ldap_lookup_info, &ldapdn_lookup_info, &ldapm_lookup_info };
1519 lookup_module_info ldap_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
1521 /* End of lookups/ldap.c */