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 #ifdef LDAP_OPT_X_TLS_CACERTFILE
435 if (eldap_ca_cert_file != NULL)
437 ldap_set_option(ld, LDAP_OPT_X_TLS_CACERTFILE, eldap_ca_cert_file);
440 #ifdef LDAP_OPT_X_TLS_CACERTDIR
441 if (eldap_ca_cert_dir != NULL)
443 ldap_set_option(ld, LDAP_OPT_X_TLS_CACERTDIR, eldap_ca_cert_dir);
446 #ifdef LDAP_OPT_X_TLS_CERTFILE
447 if (eldap_cert_file != NULL)
449 ldap_set_option(ld, LDAP_OPT_X_TLS_CERTFILE, eldap_cert_file);
452 #ifdef LDAP_OPT_X_TLS_KEYFILE
453 if (eldap_cert_key != NULL)
455 ldap_set_option(ld, LDAP_OPT_X_TLS_KEYFILE, eldap_cert_key);
458 #ifdef LDAP_OPT_X_TLS_CIPHER_SUITE
459 if (eldap_cipher_suite != NULL)
461 ldap_set_option(ld, LDAP_OPT_X_TLS_CIPHER_SUITE, eldap_cipher_suite);
464 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
465 if (eldap_require_cert != NULL)
467 int cert_option = LDAP_OPT_X_TLS_NEVER;
468 if (Ustrcmp(eldap_require_cert, "hard") == 0)
470 cert_option = LDAP_OPT_X_TLS_HARD;
472 else if (Ustrcmp(eldap_require_cert, "demand") == 0)
474 cert_option = LDAP_OPT_X_TLS_DEMAND;
476 else if (Ustrcmp(eldap_require_cert, "allow") == 0)
478 cert_option = LDAP_OPT_X_TLS_ALLOW;
480 else if (Ustrcmp(eldap_require_cert, "try") == 0)
482 cert_option = LDAP_OPT_X_TLS_TRY;
484 ldap_set_option(ld, LDAP_OPT_X_TLS_REQUIRE_CERT, &cert_option);
488 /* Now add this connection to the chain of cached connections */
490 lcp = store_get(sizeof(LDAP_CONNECTION));
491 lcp->host = (host == NULL)? NULL : string_copy(host);
494 lcp->password = NULL;
497 lcp->next = ldap_connections;
498 ldap_connections = lcp;
501 /* Found cached connection */
506 debug_printf("re-using cached connection to LDAP server %s%s\n",
510 /* Bind with the user/password supplied, or an anonymous bind if these values
511 are NULL, unless a cached connection is already bound with the same values. */
514 (lcp->user == NULL && user != NULL) ||
515 (lcp->user != NULL && user == NULL) ||
516 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
517 (lcp->password == NULL && password != NULL) ||
518 (lcp->password != NULL && password == NULL) ||
519 (lcp->password != NULL && password != NULL &&
520 Ustrcmp(lcp->password, password) != 0))
522 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
523 (lcp->bound)? "re-" : "", user, password);
524 #ifdef LDAP_OPT_X_TLS
525 /* The Oracle LDAP libraries (LDAP_LIB_TYPE=SOLARIS) don't support this: */
528 ldap_start_tls_s(lcp->ld, NULL, NULL);
531 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
534 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
535 "%s%s - ldap_bind() returned -1", host, porttext);
539 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
541 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
542 "%s%s - LDAP error: %s", host, porttext,
543 rc == -1 ? "result retrieval failed" : "timeout" );
548 rc = ldap_result2error( lcp->ld, result, 0 );
550 /* Invalid credentials when just checking credentials returns FAIL. This
551 stops any further servers being tried. */
553 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
556 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
558 goto RETURN_ERROR_NOMSG;
561 /* Otherwise we have a problem that doesn't stop further servers from being
564 if (rc != LDAP_SUCCESS)
566 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
567 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
571 /* Successful bind */
574 lcp->user = (user == NULL)? NULL : string_copy(user);
575 lcp->password = (password == NULL)? NULL : string_copy(password);
577 ldap_msgfree(result);
581 /* If we are just checking credentials, return OK. */
583 if (search_type == SEARCH_LDAP_AUTH)
585 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
589 /* Before doing the search, set the time and size limits (if given). Here again
590 the different implementations of LDAP have chosen to do things differently. */
592 #if defined(LDAP_OPT_SIZELIMIT)
593 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
594 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
596 lcp->ld->ld_sizelimit = sizelimit;
597 lcp->ld->ld_timelimit = timelimit;
600 /* Similarly for dereferencing aliases. Don't know if this is possible on
601 an LDAP library without LDAP_OPT_DEREF. */
603 #if defined(LDAP_OPT_DEREF)
604 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
607 /* Similarly for the referral setting; should the library follow referrals that
608 the LDAP server returns? The conditional is just in case someone uses a library
611 #if defined(LDAP_OPT_REFERRALS)
612 ldap_set_option(lcp->ld, LDAP_OPT_REFERRALS, referrals);
615 /* Start the search on the server. */
617 DEBUG(D_lookup) debug_printf("Start search\n");
619 msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
624 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
626 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
627 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
628 ldap_err2string(err));
631 *errmsg = string_sprintf("ldap_search failed");
637 /* Loop to pick up results as they come in, setting a timeout if one was
640 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
641 LDAP_RES_SEARCH_ENTRY)
645 DEBUG(D_lookup) debug_printf("ldap_result loop\n");
647 for(e = ldap_first_entry(lcp->ld, result);
649 e = ldap_next_entry(lcp->ld, e))
652 BOOL insert_space = FALSE;
654 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
656 rescount++; /* Count results */
658 /* Results for multiple entries values are separated by newlines. */
660 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
662 /* Get the DN from the last result. */
664 new_dn = US ldap_get_dn(lcp->ld, e);
669 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
671 #else /* OPENLDAP 1, UMich, Solaris */
679 /* If the data we want is actually the DN rather than any attribute values,
680 (an "ldapdn" search) add it to the data string. If there are multiple
681 entries, the DNs will be concatenated, but we test for this case below, as
682 for SEARCH_LDAP_SINGLE, and give an error. */
684 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
685 { /* condition, because of the else */
686 if (new_dn != NULL) /* below, that's for the first only */
688 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
690 attribute_found = TRUE;
694 /* Otherwise, loop through the entry, grabbing attribute values. If there's
695 only one attribute being retrieved, no attribute name is given, and the
696 result is not quoted. Multiple values are separated by (comma, space).
697 If more than one attribute is being retrieved, the data is given as a
698 sequence of name=value pairs, with the value always in quotes. If there are
699 multiple values, they are given within the quotes, comma separated. */
701 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
703 attr = US ldap_next_attribute(lcp->ld, e, ber))
707 /* Get array of values for this attribute. */
709 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
715 data = string_cat(data, &size, &ptr, US" ", 1);
718 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
719 data = string_cat(data, &size, &ptr, US"=\"", 2);
722 while (*values != NULL)
724 uschar *value = *values;
725 int len = Ustrlen(value);
727 DEBUG(D_lookup) debug_printf("LDAP attr loop %s:%s\n", attr, value);
729 if (values != firstval)
730 data = string_cat(data, &size, &ptr, US", ", 2);
732 /* For multiple attributes, the data is in quotes. We must escape
733 internal quotes, backslashes, newlines. */
738 for (j = 0; j < len; j++)
740 if (value[j] == '\n')
741 data = string_cat(data, &size, &ptr, US"\\n", 2);
744 if (value[j] == '\"' || value[j] == '\\')
745 data = string_cat(data, &size, &ptr, US"\\", 1);
746 data = string_cat(data, &size, &ptr, value+j, 1);
751 /* For single attributes, copy the value verbatim */
753 else data = string_cat(data, &size, &ptr, value, len);
755 /* Move on to the next value */
758 attribute_found = TRUE;
761 /* Closing quote at the end of the data for a named attribute. */
764 data = string_cat(data, &size, &ptr, US"\"", 1);
766 /* Free the values */
768 ldap_value_free(CSS firstval);
772 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
774 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
775 to be freed. UMich LDAP stores them in static storage and does not require
780 } /* End "for" loop for extracting attributes from an entry */
781 } /* End "for" loop for extracting entries from a result */
783 /* Free the result */
785 ldap_msgfree(result);
787 } /* End "while" loop for multiple results */
789 /* Terminate the dynamic string that we have built and reclaim unused store */
794 store_reset(data + ptr + 1);
797 /* Copy the last dn into eldap_dn */
801 eldap_dn = string_copy(dn);
802 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
804 #else /* OPENLDAP 1, UMich, Solaris */
809 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
813 *errmsg = US"ldap_result timed out";
817 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
818 provide you with a message". Other error states seem to exist where
819 ldap_result() didn't give us any message from the server at all, leaving result
820 set to NULL. Apparently, "the error parameters of the LDAP session handle will
821 be set accordingly". That's the best we can do to retrieve an error status; we
822 can't use functions like ldap_result2error because they parse a message from
823 the server, which we didn't get.
825 Annoyingly, the different implementations of LDAP have gone for different
826 methods of handling error codes and generating error messages. */
828 if (rc == -1 || result == NULL)
831 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
833 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
834 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
835 *errmsg = string_sprintf("ldap_result failed: %d, %s",
836 err, ldap_err2string(err));
838 #elif defined LDAP_LIB_NETSCAPE
839 /* Dubious (surely 'matched' is spurious here?) */
840 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
841 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
843 #else /* UMich LDAP aka OpenLDAP 1.x */
844 *errmsg = string_sprintf("ldap_result failed: %d, %s",
845 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
851 /* A return code that isn't -1 doesn't necessarily mean there were no problems
852 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
853 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
854 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
855 we don't provide that functionality when we can't. :-) */
857 if (rc != LDAP_RES_SEARCH_RESULT
858 #ifdef LDAP_RES_SEARCH_REFERENCE
859 && rc != LDAP_RES_SEARCH_REFERENCE
863 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
867 /* We have a result message from the server. This doesn't yet mean all is well.
868 We need to parse the message to find out exactly what's happened. */
870 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
872 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
873 CSS &error2, NULL, NULL, 0);
874 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
875 if (ldap_parse_rc < 0 &&
876 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
877 #ifdef LDAP_RES_SEARCH_REFERENCE
878 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
882 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
885 error1 = US ldap_err2string(rc);
887 #elif defined LDAP_LIB_NETSCAPE
888 /* Dubious (it doesn't reference 'result' at all!) */
889 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
891 #else /* UMich LDAP aka OpenLDAP 1.x */
892 rc = ldap_result2error(lcp->ld, result, 0);
893 error1 = ldap_err2string(rc);
894 error2 = lcp->ld->ld_error;
895 matched = lcp->ld->ld_matched;
898 /* Process the status as follows:
900 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
901 truncated result list.
903 (2) If we get LDAP_RES_SEARCH_REFERENCE, also just carry on. This was a
904 submitted patch that is reported to "do the right thing" with Solaris
905 LDAP libraries. (The problem it addresses apparently does not occur with
908 (3) The range of errors defined by LDAP_NAME_ERROR generally mean "that
909 object does not, or cannot, exist in the database". For those cases we
912 (4) All other non-successes here are treated as some kind of problem with
913 the lookup, so return DEFER (which is the default in error_yield).
916 DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
917 rc, ldap_err2string(rc));
919 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED
920 #ifdef LDAP_RES_SEARCH_REFERENCE
921 && rc != LDAP_RES_SEARCH_REFERENCE
925 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
927 (error1 != NULL)? error1 : US"",
928 (error2 != NULL && error2[0] != 0)? US"/" : US"",
929 (error2 != NULL)? error2 : US"",
930 (matched != NULL && matched[0] != 0)? US"/" : US"",
931 (matched != NULL)? matched : US"");
933 #if defined LDAP_NAME_ERROR
934 if (LDAP_NAME_ERROR(rc))
935 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
938 if (rc == LDAP_NO_SUCH_OBJECT)
942 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
948 /* The search succeeded. Check if we have too many results */
950 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
952 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
953 "(filter not specific enough?)", rescount);
954 goto RETURN_ERROR_BREAK;
957 /* Check if we have too few (zero) entries */
961 *errmsg = string_sprintf("LDAP search: no results");
963 goto RETURN_ERROR_BREAK;
966 /* If an entry was found, but it had no attributes, we behave as if no entries
967 were found, that is, the lookup failed. */
969 if (!attribute_found)
971 *errmsg = US"LDAP search: found no attributes";
976 /* Otherwise, it's all worked */
978 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
982 if (result != NULL) ldap_msgfree(result);
983 ldap_free_urldesc(ludp);
992 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
995 if (result != NULL) ldap_msgfree(result);
996 if (ludp != NULL) ldap_free_urldesc(ludp);
998 #if defined LDAP_LIB_OPENLDAP2
999 if (error2 != NULL) ldap_memfree(error2);
1000 if (matched != NULL) ldap_memfree(matched);
1008 /*************************************************
1009 * Internal search control function *
1010 *************************************************/
1012 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
1013 and eldapm_find() with a difference in the "search_type" argument. It controls
1014 calls to perform_ldap_search() which actually does the work. We call that
1015 repeatedly for certain types of defer in the case when the URL contains no host
1016 name and eldap_default_servers is set to a list of servers to try. This gives
1017 more control than just passing over a list of hosts to ldap_open() because it
1018 handles other kinds of defer as well as just a failure to open. Note that the
1019 URL is defined to contain either zero or one "hostport" only.
1021 Parameter data in addition to the URL can be passed as preceding text in the
1022 string, as items of the form XXX=yyy. The URL itself can be detected because it
1023 must begin "ldapx://", where x is empty, s, or i.
1026 ldap_url the URL to be looked up, optionally preceded by other parameter
1028 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
1029 SEARCH_LDAP_SINGLE allows values from one entry only
1030 SEARCH_LDAP_DN gets the DN from one entry
1031 res set to point at the result
1032 errmsg set to point a message if result is not OK
1034 Returns: OK or FAIL or DEFER
1038 control_ldap_search(uschar *ldap_url, int search_type, uschar **res,
1041 BOOL defer_break = FALSE;
1042 int timelimit = LDAP_NO_LIMIT;
1043 int sizelimit = LDAP_NO_LIMIT;
1046 int dereference = LDAP_DEREF_NEVER;
1047 void* referrals = LDAP_OPT_ON;
1048 uschar *url = ldap_url;
1050 uschar *user = NULL;
1051 uschar *password = NULL;
1052 uschar *server, *list;
1055 while (isspace(*url)) url++;
1057 /* Until the string begins "ldap", search for the other parameter settings that
1058 are recognized. They are of the form NAME=VALUE, with the value being
1059 optionally double-quoted. There must still be a space after it, however. No
1060 NAME has the value "ldap". */
1062 while (strncmpic(url, US"ldap", 4) != 0)
1065 while (*url != 0 && *url != '=') url++;
1070 namelen = ++url - name;
1071 value = string_dequote(&url);
1074 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1075 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1076 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1077 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1078 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1079 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1081 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1083 #ifdef LDAP_OPT_DEREF
1084 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1086 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1087 else if (strcmpic(value, US"searching") == 0)
1088 dereference = LDAP_DEREF_SEARCHING;
1089 else if (strcmpic(value, US"finding") == 0)
1090 dereference = LDAP_DEREF_FINDING;
1091 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1094 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1096 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1097 "library - cannot use \"dereference\"");
1098 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1103 #ifdef LDAP_OPT_REFERRALS
1104 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1106 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1107 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1110 *errmsg = string_sprintf("LDAP option REFERRALS is not \"follow\" "
1112 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1117 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1119 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1120 "library - cannot use \"referrals\"");
1121 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1129 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1131 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1134 while (isspace(*url)) url++;
1138 *errmsg = US"malformed parameter setting precedes LDAP URL";
1139 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1143 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1144 but it seems that not all behave like this. The DN for the user is often the
1145 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1146 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1147 far too complicated. */
1153 for (s = user; *s != 0; s++)
1156 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1161 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1162 ((d >= 'a')? (10 + d - 'a') : d - '0');
1171 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1172 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1173 tcplimit, dereference, (referrals == LDAP_OPT_ON)? "on" : "off");
1175 /* If the request is just to check authentication, some credentials must
1176 be given. The password must not be empty because LDAP binds with an empty
1177 password are considered anonymous, and will succeed on most installations. */
1179 if (search_type == SEARCH_LDAP_AUTH)
1181 if (user == NULL || password == NULL)
1183 *errmsg = US"ldapauth lookups must specify the username and password";
1186 if (password[0] == 0)
1188 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1193 /* Check for valid ldap url starters */
1196 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1197 if (Ustrncmp(p, "://", 3) != 0)
1199 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1200 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1201 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1205 /* No default servers, or URL contains a server name: just one attempt */
1207 if (eldap_default_servers == NULL || p[3] != '/')
1209 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1210 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1214 /* Loop through the default servers until OK or FAIL */
1216 list = eldap_default_servers;
1217 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1221 uschar *colon = Ustrchr(server, ':');
1225 port = Uatoi(colon+1);
1227 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1228 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1230 if (rc != DEFER || defer_break) return rc;
1238 /*************************************************
1239 * Find entry point *
1240 *************************************************/
1242 /* See local README for interface description. The different kinds of search
1243 are handled by a common function, with a flag to differentiate between them.
1244 The handle and filename arguments are not used. */
1247 eldap_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1248 uschar **result, uschar **errmsg, BOOL *do_cache)
1250 /* Keep picky compilers happy */
1251 do_cache = do_cache;
1252 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1256 eldapm_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1257 uschar **result, uschar **errmsg, BOOL *do_cache)
1259 /* Keep picky compilers happy */
1260 do_cache = do_cache;
1261 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1265 eldapdn_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1266 uschar **result, uschar **errmsg, BOOL *do_cache)
1268 /* Keep picky compilers happy */
1269 do_cache = do_cache;
1270 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1274 eldapauth_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1275 uschar **result, uschar **errmsg, BOOL *do_cache)
1277 /* Keep picky compilers happy */
1278 do_cache = do_cache;
1279 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1284 /*************************************************
1285 * Open entry point *
1286 *************************************************/
1288 /* See local README for interface description. */
1291 eldap_open(uschar *filename, uschar **errmsg)
1293 return (void *)(1); /* Just return something non-null */
1298 /*************************************************
1299 * Tidy entry point *
1300 *************************************************/
1302 /* See local README for interface description.
1303 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1308 LDAP_CONNECTION *lcp = NULL;
1311 while ((lcp = ldap_connections) != NULL)
1313 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1315 ldap_unbind(lcp->ld);
1316 ldap_connections = lcp->next;
1322 /*************************************************
1323 * Quote entry point *
1324 *************************************************/
1326 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1327 quoting have to be done: LDAP quoting, and URL quoting. The current
1328 specification is the result of a suggestion by Brian Candler. It recognizes
1331 (1) For text that appears in a search filter, the following escapes are
1332 required (see RFC 2254):
1340 Then the entire filter text must be URL-escaped. This kind of quoting is
1341 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1342 in the input string, because that's a terminator.
1344 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1348 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1349 must be escaped, as must a leading #. Then the string must be URL-quoted.
1350 This type of quoting is implemented by ${quote_ldap_dn:....}.
1352 For URL quoting, the only characters that need not be quoted are the
1357 All the others must be hexified and preceded by %. This includes the
1358 backslashes used for LDAP quoting.
1360 For a DN that is given in the USER parameter for authentication, we need the
1361 same initial quoting as (2) but in this case, the result must NOT be
1362 URL-escaped, because it isn't a URL. The way this is handled is by
1363 de-URL-quoting the text when processing the USER parameter in
1364 control_ldap_search() above. That means that the same quote operator can be
1365 used. This has the additional advantage that spaces in the DN won't cause
1366 parsing problems. For example:
1368 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1370 should be safe if there are spaces in $1.
1374 s the string to be quoted
1375 opt additional option text or NULL if none
1376 only "dn" is recognized
1378 Returns: the processed string or NULL for a bad option
1383 /* The characters in this string, together with alphanumerics, never need
1384 quoting in any way. */
1386 #define ALWAYS_LITERAL "!$'-._"
1388 /* The special characters in this string do not need to be URL-quoted. The set
1389 is a bit larger than the general literals. */
1391 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1393 /* The following macros define the characters that are quoted by quote_ldap and
1394 quote_ldap_dn, respectively. */
1396 #define LDAP_QUOTE "*()\\"
1397 #define LDAP_DN_QUOTE ",+\"\\<>;"
1402 eldap_quote(uschar *s, uschar *opt)
1411 /* Test for a DN quotation. */
1415 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1419 /* Compute how much extra store we need for the string. This doesn't have to be
1420 exact as long as it isn't an underestimate. The worst case is the addition of 5
1421 extra bytes for a single character. This occurs for certain characters in DNs,
1422 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1423 possibly escaped character. The really fast way would be just to test for
1424 non-alphanumerics, but it is probably better to spot a few others that are
1425 never escaped, because if there are no specials at all, we can avoid copying
1428 while ((c = *t++) != 0)
1431 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1433 if (count == 0) return s;
1435 /* Get sufficient store to hold the quoted string */
1437 t = quoted = store_get(len + count + 1);
1439 /* Handle plain quote_ldap */
1443 while ((c = *s++) != 0)
1447 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1449 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1453 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1455 sprintf(CS t, "%%%02X", c);
1460 *t++ = c; /* unquoted character */
1464 /* Handle quote_ldap_dn */
1468 uschar *ss = s + len;
1470 /* Find the last char before any trailing spaces */
1472 while (ss > s && ss[-1] == ' ') ss--;
1474 /* Quote leading spaces and sharps */
1478 if (*s != ' ' && *s != '#') break;
1479 sprintf(CS t, "%%5C%%%02X", *s);
1483 /* Handle the rest of the string, up to the trailing spaces */
1490 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1492 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1493 t += 3; /* fall through to check URL */
1495 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1497 sprintf(CS t, "%%%02X", c);
1502 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1505 /* Handle the trailing spaces */
1509 Ustrncpy(t, "%5C%20", 6);
1514 /* Terminate the new string and return */
1522 /*************************************************
1523 * Version reporting entry point *
1524 *************************************************/
1526 /* See local README for interface description. */
1528 #include "../version.h"
1531 ldap_version_report(FILE *f)
1534 fprintf(f, "Library version: LDAP: Exim version %s\n", EXIM_VERSION_STR);
1539 static lookup_info ldap_lookup_info = {
1540 US"ldap", /* lookup name */
1541 lookup_querystyle, /* query-style lookup */
1542 eldap_open, /* open function */
1543 NULL, /* check function */
1544 eldap_find, /* find function */
1545 NULL, /* no close function */
1546 eldap_tidy, /* tidy function */
1547 eldap_quote, /* quoting function */
1548 ldap_version_report /* version reporting */
1551 static lookup_info ldapdn_lookup_info = {
1552 US"ldapdn", /* lookup name */
1553 lookup_querystyle, /* query-style lookup */
1554 eldap_open, /* sic */ /* open function */
1555 NULL, /* check function */
1556 eldapdn_find, /* find function */
1557 NULL, /* no close function */
1558 eldap_tidy, /* sic */ /* tidy function */
1559 eldap_quote, /* sic */ /* quoting function */
1560 NULL /* no version reporting (redundant) */
1563 static lookup_info ldapm_lookup_info = {
1564 US"ldapm", /* lookup name */
1565 lookup_querystyle, /* query-style lookup */
1566 eldap_open, /* sic */ /* open function */
1567 NULL, /* check function */
1568 eldapm_find, /* find function */
1569 NULL, /* no close function */
1570 eldap_tidy, /* sic */ /* tidy function */
1571 eldap_quote, /* sic */ /* quoting function */
1572 NULL /* no version reporting (redundant) */
1576 #define ldap_lookup_module_info _lookup_module_info
1579 static lookup_info *_lookup_list[] = { &ldap_lookup_info, &ldapdn_lookup_info, &ldapm_lookup_info };
1580 lookup_module_info ldap_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
1582 /* End of lookups/ldap.c */