1 /* $Cambridge: exim/src/src/lookups/ldap.c,v 1.12 2006/07/17 09:18:09 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2006 */
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. The code below uses some "old" LDAP interfaces that
35 are deprecated in OpenLDAP. I don't know their status in other LDAP
36 implementations. LDAP_DEPRECATED causes their prototypes to be defined in
39 #define LDAP_DEPRECATED 1
45 /* Annoyingly, the different LDAP libraries handle errors in different ways,
46 and some other things too. There doesn't seem to be an automatic way of
47 distinguishing between them. Local/Makefile should contain a setting of
48 LDAP_LIB_TYPE, which in turn causes appropriate macros to be defined for the
49 different kinds. Those that matter are:
52 LDAP_LIB_SOLARIS with synonym LDAP_LIB_SOLARIS7
55 These others may be defined, but are in fact the default, so are not tested:
61 #if defined(LDAP_LIB_SOLARIS7) && ! defined(LDAP_LIB_SOLARIS)
62 #define LDAP_LIB_SOLARIS
66 /* Just in case LDAP_NO_LIMIT is not defined by some of these libraries. */
69 #define LDAP_NO_LIMIT 0
73 /* Just in case LDAP_DEREF_NEVER is not defined */
75 #ifndef LDAP_DEREF_NEVER
76 #define LDAP_DEREF_NEVER 0
80 /* Four types of LDAP search are implemented */
82 #define SEARCH_LDAP_MULTIPLE 0 /* Get attributes from multiple entries */
83 #define SEARCH_LDAP_SINGLE 1 /* Get attributes from one entry only */
84 #define SEARCH_LDAP_DN 2 /* Get just the DN from one entry */
85 #define SEARCH_LDAP_AUTH 3 /* Just checking for authentication */
87 /* In all 4 cases, the DN is left in $ldap_dn (which post-dates the
88 SEARCH_LDAP_DN lookup). */
91 /* Structure and anchor for caching connections. */
93 typedef struct ldap_connection {
94 struct ldap_connection *next;
103 static LDAP_CONNECTION *ldap_connections = NULL;
107 /*************************************************
108 * Internal search function *
109 *************************************************/
111 /* This is the function that actually does the work. It is called (indirectly
112 via control_ldap_search) from eldap_find(), eldapauth_find(), eldapdn_find(),
113 and eldapm_find(), with a difference in the "search_type" argument.
115 The case of eldapauth_find() is special in that all it does is do
116 authentication, returning OK or FAIL as appropriate. This isn't used as a
117 lookup. Instead, it is called from expand.c as an expansion condition test.
119 The DN from a successful lookup is placed in $ldap_dn. This feature postdates
120 the provision of the SEARCH_LDAP_DN facility for returning just the DN as the
124 ldap_url the URL to be looked up
125 server server host name, when URL contains none
126 s_port server port, used when URL contains no name
127 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
128 SEARCH_LDAP_SINGLE allows values from one entry only
129 SEARCH_LDAP_DN gets the DN from one entry
130 res set to point at the result (not used for ldapauth)
131 errmsg set to point a message if result is not OK
132 defer_break set TRUE if no more servers to be tried after a DEFER
133 user user name for authentication, or NULL
134 password password for authentication, or NULL
135 sizelimit max number of entries returned, or 0 for no limit
136 timelimit max time to wait, or 0 for no limit
137 tcplimit max time for network activity, e.g. connect, or 0 for OS default
138 deference the dereference option, which is one of
139 LDAP_DEREF_{NEVER,SEARCHING,FINDING,ALWAYS}
140 referrals the referral option, which is LDAP_OPT_ON or LDAP_OPT_OFF
142 Returns: OK or FAIL or DEFER
143 FAIL is given only if a lookup was performed successfully, but
148 perform_ldap_search(uschar *ldap_url, uschar *server, int s_port, int search_type,
149 uschar **res, uschar **errmsg, BOOL *defer_break, uschar *user, uschar *password,
150 int sizelimit, int timelimit, int tcplimit, int dereference, void *referrals)
152 LDAPURLDesc *ludp = NULL;
153 LDAPMessage *result = NULL;
155 LDAP_CONNECTION *lcp;
157 struct timeval timeout;
158 struct timeval *timeoutptr = NULL;
169 uschar *error1 = NULL; /* string representation of errcode (static) */
170 uschar *error2 = NULL; /* error message from the server */
171 uschar *matched = NULL; /* partially matched DN */
174 int error_yield = DEFER;
176 int rc, ldap_rc, ldap_parse_rc;
181 BOOL attribute_found = FALSE;
185 debug_printf("perform_ldap_search: ldap%s URL = \"%s\" server=%s port=%d "
186 "sizelimit=%d timelimit=%d tcplimit=%d\n",
187 (search_type == SEARCH_LDAP_MULTIPLE)? "m" :
188 (search_type == SEARCH_LDAP_DN)? "dn" :
189 (search_type == SEARCH_LDAP_AUTH)? "auth" : "",
190 ldap_url, server, s_port, sizelimit, timelimit, tcplimit);
192 /* Check if LDAP thinks the URL is a valid LDAP URL. We assume that if the LDAP
193 library that is in use doesn't recognize, say, "ldapi", it will barf here. */
195 if (!ldap_is_ldap_url(CS ldap_url))
197 *errmsg = string_sprintf("ldap_is_ldap_url: not an LDAP url \"%s\"\n",
199 goto RETURN_ERROR_BREAK;
204 if ((rc = ldap_url_parse(CS ldap_url, &ludp)) != 0)
206 *errmsg = string_sprintf("ldap_url_parse: (error %d) parsing \"%s\"\n", rc,
208 goto RETURN_ERROR_BREAK;
211 /* If the host name is empty, take it from the separate argument, if one is
212 given. OpenLDAP 2.0.6 sets an unset hostname to "" rather than empty, but
213 expects NULL later in ldap_init() to mean "default", annoyingly. In OpenLDAP
214 2.0.11 this has changed (it uses NULL). */
216 if ((ludp->lud_host == NULL || ludp->lud_host[0] == 0) && server != NULL)
223 host = US ludp->lud_host;
224 if (host != NULL && host[0] == 0) host = NULL;
225 port = ludp->lud_port;
228 DEBUG(D_lookup) debug_printf("after ldap_url_parse: host=%s port=%d\n",
231 if (port == 0) port = LDAP_PORT; /* Default if none given */
232 sprintf(CS porttext, ":%d", port); /* For messages */
234 /* If the "host name" is actually a path, we are going to connect using a Unix
235 socket, regardless of whether "ldapi" was actually specified or not. This means
236 that a Unix socket can be declared in eldap_default_servers, and "traditional"
237 LDAP queries using just "ldap" can be used ("ldaps" is similarly overridden).
238 The path may start with "/" or it may already be escaped as "%2F" if it was
239 actually declared that way in eldap_default_servers. (I did it that way the
240 first time.) If the host name is not a path, the use of "ldapi" causes an
241 error, except in the default case. (But lud_scheme doesn't seem to exist in
246 if ((host[0] == '/' || Ustrncmp(host, "%2F", 3) == 0))
249 porttext[0] = 0; /* Remove port from messages */
252 #if defined LDAP_LIB_OPENLDAP2
253 else if (strncmp(ludp->lud_scheme, "ldapi", 5) == 0)
255 *errmsg = string_sprintf("ldapi requires an absolute path (\"%s\" given)",
262 /* Count the attributes; we need this later to tell us how to format results */
264 for (attrp = USS ludp->lud_attrs; attrp != NULL && *attrp != NULL; attrp++)
267 /* See if we can find a cached connection to this host. The port is not
268 relevant for ldapi. The host name pointer is set to NULL if no host was given
269 (implying the library default), rather than to the empty string. Note that in
270 this case, there is no difference between ldap and ldapi. */
272 for (lcp = ldap_connections; lcp != NULL; lcp = lcp->next)
274 if ((host == NULL) != (lcp->host == NULL) ||
275 (host != NULL && strcmpic(lcp->host, host) != 0))
277 if (ldapi || port == lcp->port) break;
280 /* Use this network timeout in any requests. */
284 timeout.tv_sec = tcplimit;
286 timeoutptr = &timeout;
289 /* If no cached connection found, we must open a connection to the server. If
290 the server name is actually an absolute path, we set ldapi=TRUE above. This
291 requests connection via a Unix socket. However, as far as I know, only OpenLDAP
292 supports the use of sockets, and the use of ldap_initialize(). */
299 /* --------------------------- OpenLDAP ------------------------ */
301 /* There seems to be a preference under OpenLDAP for ldap_initialize()
302 instead of ldap_init(), though I have as yet been unable to find
303 documentation that says this. (OpenLDAP documentation is sparse to
304 non-existent). So we handle OpenLDAP differently here. Also, support for
305 ldapi seems to be OpenLDAP-only at present. */
307 #ifdef LDAP_LIB_OPENLDAP2
309 /* We now need an empty string for the default host. Get some store in which
310 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
311 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
312 than the host name + "ldaps:///" plus : and a port number, say 20 + the
313 length of the host name. What we get should accommodate both, easily. */
315 uschar *shost = (host == NULL)? US"" : host;
316 uschar *init_url = store_get(20 + 3 * Ustrlen(shost));
319 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
320 contain the path name, with slashes escaped as %2F. */
325 init_ptr = init_url + 8;
326 Ustrcpy(init_url, "ldapi://");
327 while ((ch = *shost++) != 0)
331 Ustrncpy(init_ptr, "%2F", 3);
334 else *init_ptr++ = ch;
339 /* This is not an ldapi call. Just build a URI with the protocol type, host
344 init_ptr = Ustrchr(ldap_url, '/');
345 Ustrncpy(init_url, ldap_url, init_ptr - ldap_url);
346 init_ptr = init_url + (init_ptr - ldap_url);
347 sprintf(CS init_ptr, "//%s:%d/", shost, port);
350 /* Call ldap_initialize() and check the result */
352 DEBUG(D_lookup) debug_printf("ldap_initialize with URL %s\n", init_url);
353 rc = ldap_initialize(&ld, CS init_url);
354 if (rc != LDAP_SUCCESS)
356 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
360 store_reset(init_url); /* Might as well save memory when we can */
363 /* ------------------------- Not OpenLDAP ---------------------- */
365 /* For libraries other than OpenLDAP, use ldap_init(). */
367 #else /* LDAP_LIB_OPENLDAP2 */
368 ld = ldap_init(CS host, port);
369 #endif /* LDAP_LIB_OPENLDAP2 */
371 /* -------------------------------------------------------------- */
374 /* Handle failure to initialize */
378 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
379 host, porttext, strerror(errno));
383 /* Set the TCP connect time limit if available. This is something that is
384 in Netscape SDK v4.1; I don't know about other libraries. */
386 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
389 int timeout1000 = tcplimit*1000;
390 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
394 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
395 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)¬imeout);
399 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
401 #ifdef LDAP_OPT_NETWORK_TIMEOUT
403 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
406 /* I could not get TLS to work until I set the version to 3. That version
407 seems to be the default nowadays. The RFC is dated 1997, so I would hope
408 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
409 been set, go for v3 if we can. */
411 if (eldap_version < 0)
414 eldap_version = LDAP_VERSION3;
420 #ifdef LDAP_OPT_PROTOCOL_VERSION
421 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
424 DEBUG(D_lookup) debug_printf("initialized for LDAP (v%d) server %s%s\n",
425 eldap_version, host, porttext);
427 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
428 for "ldaps" and soft otherwise. */
430 #ifdef LDAP_OPT_X_TLS
434 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
436 tls_option = LDAP_OPT_X_TLS_HARD;
437 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_HARD set\n");
441 tls_option = LDAP_OPT_X_TLS_TRY;
442 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_TRY set\n");
444 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
446 #endif /* LDAP_OPT_X_TLS */
448 /* Now add this connection to the chain of cached connections */
450 lcp = store_get(sizeof(LDAP_CONNECTION));
451 lcp->host = (host == NULL)? NULL : string_copy(host);
454 lcp->password = NULL;
457 lcp->next = ldap_connections;
458 ldap_connections = lcp;
461 /* Found cached connection */
466 debug_printf("re-using cached connection to LDAP server %s%s\n",
470 /* Bind with the user/password supplied, or an anonymous bind if these values
471 are NULL, unless a cached connection is already bound with the same values. */
474 (lcp->user == NULL && user != NULL) ||
475 (lcp->user != NULL && user == NULL) ||
476 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
477 (lcp->password == NULL && password != NULL) ||
478 (lcp->password != NULL && password == NULL) ||
479 (lcp->password != NULL && password != NULL &&
480 Ustrcmp(lcp->password, password) != 0))
482 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
483 (lcp->bound)? "re-" : "", user, password);
484 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
487 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
488 "%s%s - ldap_bind() returned -1", host, porttext);
492 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
494 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
495 "%s%s - LDAP error: %s", host, porttext,
496 rc == -1 ? "result retrieval failed" : "timeout" );
501 rc = ldap_result2error( lcp->ld, result, 0 );
503 /* Invalid credentials when just checking credentials returns FAIL. This
504 stops any further servers being tried. */
506 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
509 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
511 goto RETURN_ERROR_NOMSG;
514 /* Otherwise we have a problem that doesn't stop further servers from being
517 if (rc != LDAP_SUCCESS)
519 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
520 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
524 /* Successful bind */
527 lcp->user = (user == NULL)? NULL : string_copy(user);
528 lcp->password = (password == NULL)? NULL : string_copy(password);
530 ldap_msgfree(result);
534 /* If we are just checking credentials, return OK. */
536 if (search_type == SEARCH_LDAP_AUTH)
538 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
542 /* Before doing the search, set the time and size limits (if given). Here again
543 the different implementations of LDAP have chosen to do things differently. */
545 #if defined(LDAP_OPT_SIZELIMIT)
546 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
547 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
549 lcp->ld->ld_sizelimit = sizelimit;
550 lcp->ld->ld_timelimit = timelimit;
553 /* Similarly for dereferencing aliases. Don't know if this is possible on
554 an LDAP library without LDAP_OPT_DEREF. */
556 #if defined(LDAP_OPT_DEREF)
557 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
560 /* Similarly for the referral setting; should the library follow referrals that
561 the LDAP server returns? The conditional is just in case someone uses a library
564 #if defined(LDAP_OPT_REFERRALS)
565 ldap_set_option(lcp->ld, LDAP_OPT_REFERRALS, referrals);
568 /* Start the search on the server. */
570 DEBUG(D_lookup) debug_printf("Start search\n");
572 msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
577 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
579 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
580 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
581 ldap_err2string(err));
584 *errmsg = string_sprintf("ldap_search failed");
590 /* Loop to pick up results as they come in, setting a timeout if one was
593 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
594 LDAP_RES_SEARCH_ENTRY)
598 DEBUG(D_lookup) debug_printf("ldap_result loop\n");
600 for(e = ldap_first_entry(lcp->ld, result);
602 e = ldap_next_entry(lcp->ld, e))
605 BOOL insert_space = FALSE;
607 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
609 rescount++; /* Count results */
611 /* Results for multiple entries values are separated by newlines. */
613 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
615 /* Get the DN from the last result. */
617 new_dn = US ldap_get_dn(lcp->ld, e);
622 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
624 #else /* OPENLDAP 1, UMich, Solaris */
632 /* If the data we want is actually the DN rather than any attribute values,
633 (an "ldapdn" search) add it to the data string. If there are multiple
634 entries, the DNs will be concatenated, but we test for this case below, as
635 for SEARCH_LDAP_SINGLE, and give an error. */
637 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
638 { /* condition, because of the else */
639 if (new_dn != NULL) /* below, that's for the first only */
641 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
643 attribute_found = TRUE;
647 /* Otherwise, loop through the entry, grabbing attribute values. If there's
648 only one attribute being retrieved, no attribute name is given, and the
649 result is not quoted. Multiple values are separated by (comma, space).
650 If more than one attribute is being retrieved, the data is given as a
651 sequence of name=value pairs, with the value always in quotes. If there are
652 multiple values, they are given within the quotes, comma separated. */
654 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
656 attr = US ldap_next_attribute(lcp->ld, e, ber))
660 /* Get array of values for this attribute. */
662 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
668 data = string_cat(data, &size, &ptr, US" ", 1);
671 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
672 data = string_cat(data, &size, &ptr, US"=\"", 2);
675 while (*values != NULL)
677 uschar *value = *values;
678 int len = Ustrlen(value);
680 DEBUG(D_lookup) debug_printf("LDAP attr loop %s:%s\n", attr, value);
682 if (values != firstval)
683 data = string_cat(data, &size, &ptr, US", ", 2);
685 /* For multiple attributes, the data is in quotes. We must escape
686 internal quotes, backslashes, newlines. */
691 for (j = 0; j < len; j++)
693 if (value[j] == '\n')
694 data = string_cat(data, &size, &ptr, US"\\n", 2);
697 if (value[j] == '\"' || value[j] == '\\')
698 data = string_cat(data, &size, &ptr, US"\\", 1);
699 data = string_cat(data, &size, &ptr, value+j, 1);
704 /* For single attributes, copy the value verbatim */
706 else data = string_cat(data, &size, &ptr, value, len);
708 /* Move on to the next value */
711 attribute_found = TRUE;
714 /* Closing quote at the end of the data for a named attribute. */
717 data = string_cat(data, &size, &ptr, US"\"", 1);
719 /* Free the values */
721 ldap_value_free(CSS firstval);
725 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
727 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
728 to be freed. UMich LDAP stores them in static storage and does not require
733 } /* End "for" loop for extracting attributes from an entry */
734 } /* End "for" loop for extracting entries from a result */
736 /* Free the result */
738 ldap_msgfree(result);
740 } /* End "while" loop for multiple results */
742 /* Terminate the dynamic string that we have built and reclaim unused store */
747 store_reset(data + ptr + 1);
750 /* Copy the last dn into eldap_dn */
754 eldap_dn = string_copy(dn);
755 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
757 #else /* OPENLDAP 1, UMich, Solaris */
762 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
766 *errmsg = US"ldap_result timed out";
770 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
771 provide you with a message". Other error states seem to exist where
772 ldap_result() didn't give us any message from the server at all, leaving result
773 set to NULL. Apparently, "the error parameters of the LDAP session handle will
774 be set accordingly". That's the best we can do to retrieve an error status; we
775 can't use functions like ldap_result2error because they parse a message from
776 the server, which we didn't get.
778 Annoyingly, the different implementations of LDAP have gone for different
779 methods of handling error codes and generating error messages. */
781 if (rc == -1 || result == NULL)
784 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
786 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
787 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
788 *errmsg = string_sprintf("ldap_result failed: %d, %s",
789 err, ldap_err2string(err));
791 #elif defined LDAP_LIB_NETSCAPE
792 /* Dubious (surely 'matched' is spurious here?) */
793 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
794 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
796 #else /* UMich LDAP aka OpenLDAP 1.x */
797 *errmsg = string_sprintf("ldap_result failed: %d, %s",
798 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
804 /* A return code that isn't -1 doesn't necessarily mean there were no problems
805 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
806 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
807 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
808 we don't provide that functionality when we can't. :-) */
810 if (rc != LDAP_RES_SEARCH_RESULT
811 #ifdef LDAP_RES_SEARCH_REFERENCE
812 && rc != LDAP_RES_SEARCH_REFERENCE
816 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
820 /* We have a result message from the server. This doesn't yet mean all is well.
821 We need to parse the message to find out exactly what's happened. */
823 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
825 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
826 CSS &error2, NULL, NULL, 0);
827 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
828 if (ldap_parse_rc < 0 &&
829 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
830 #ifdef LDAP_RES_SEARCH_REFERENCE
831 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
835 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
838 error1 = US ldap_err2string(rc);
840 #elif defined LDAP_LIB_NETSCAPE
841 /* Dubious (it doesn't reference 'result' at all!) */
842 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
844 #else /* UMich LDAP aka OpenLDAP 1.x */
845 rc = ldap_result2error(lcp->ld, result, 0);
846 error1 = ldap_err2string(rc);
847 error2 = lcp->ld->ld_error;
848 matched = lcp->ld->ld_matched;
851 /* Process the status as follows:
853 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
854 truncated result list.
856 (2) The range of errors defined by LDAP_NAME_ERROR generally mean "that
857 object does not, or cannot, exist in the database". For those cases we
860 (3) All other non-successes here are treated as some kind of problem with
861 the lookup, so return DEFER (which is the default in error_yield).
864 DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
865 rc, ldap_err2string(rc));
867 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED)
869 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
871 (error1 != NULL)? error1 : US"",
872 (error2 != NULL && error2[0] != 0)? US"/" : US"",
873 (error2 != NULL)? error2 : US"",
874 (matched != NULL && matched[0] != 0)? US"/" : US"",
875 (matched != NULL)? matched : US"");
877 #if defined LDAP_NAME_ERROR
878 if (LDAP_NAME_ERROR(rc))
879 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
882 if (rc == LDAP_NO_SUCH_OBJECT)
886 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
892 /* The search succeeded. Check if we have too many results */
894 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
896 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
897 "(filter not specific enough?)", rescount);
898 goto RETURN_ERROR_BREAK;
901 /* Check if we have too few (zero) entries */
905 *errmsg = string_sprintf("LDAP search: no results");
907 goto RETURN_ERROR_BREAK;
910 /* If an entry was found, but it had no attributes, we behave as if no entries
911 were found, that is, the lookup failed. */
913 if (!attribute_found)
915 *errmsg = US"LDAP search: found no attributes";
920 /* Otherwise, it's all worked */
922 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
926 if (result != NULL) ldap_msgfree(result);
927 ldap_free_urldesc(ludp);
936 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
939 if (result != NULL) ldap_msgfree(result);
940 if (ludp != NULL) ldap_free_urldesc(ludp);
942 #if defined LDAP_LIB_OPENLDAP2
943 if (error2 != NULL) ldap_memfree(error2);
944 if (matched != NULL) ldap_memfree(matched);
952 /*************************************************
953 * Internal search control function *
954 *************************************************/
956 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
957 and eldapm_find() with a difference in the "search_type" argument. It controls
958 calls to perform_ldap_search() which actually does the work. We call that
959 repeatedly for certain types of defer in the case when the URL contains no host
960 name and eldap_default_servers is set to a list of servers to try. This gives
961 more control than just passing over a list of hosts to ldap_open() because it
962 handles other kinds of defer as well as just a failure to open. Note that the
963 URL is defined to contain either zero or one "hostport" only.
965 Parameter data in addition to the URL can be passed as preceding text in the
966 string, as items of the form XXX=yyy. The URL itself can be detected because it
967 must begin "ldapx://", where x is empty, s, or i.
970 ldap_url the URL to be looked up, optionally preceded by other parameter
972 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
973 SEARCH_LDAP_SINGLE allows values from one entry only
974 SEARCH_LDAP_DN gets the DN from one entry
975 res set to point at the result
976 errmsg set to point a message if result is not OK
978 Returns: OK or FAIL or DEFER
982 control_ldap_search(uschar *ldap_url, int search_type, uschar **res,
985 BOOL defer_break = FALSE;
986 int timelimit = LDAP_NO_LIMIT;
987 int sizelimit = LDAP_NO_LIMIT;
990 int dereference = LDAP_DEREF_NEVER;
991 void* referrals = LDAP_OPT_ON;
992 uschar *url = ldap_url;
995 uschar *password = NULL;
996 uschar *server, *list;
999 while (isspace(*url)) url++;
1001 /* Until the string begins "ldap", search for the other parameter settings that
1002 are recognized. They are of the form NAME=VALUE, with the value being
1003 optionally double-quoted. There must still be a space after it, however. No
1004 NAME has the value "ldap". */
1006 while (strncmpic(url, US"ldap", 4) != 0)
1009 while (*url != 0 && *url != '=') url++;
1014 namelen = ++url - name;
1015 value = string_dequote(&url);
1018 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1019 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1020 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1021 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1022 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1023 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1025 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1027 #ifdef LDAP_OPT_DEREF
1028 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1030 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1031 else if (strcmpic(value, US"searching") == 0)
1032 dereference = LDAP_DEREF_SEARCHING;
1033 else if (strcmpic(value, US"finding") == 0)
1034 dereference = LDAP_DEREF_FINDING;
1035 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1038 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1040 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1041 "library - cannot use \"dereference\"");
1042 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1047 #ifdef LDAP_OPT_REFERRALS
1048 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1050 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1051 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1054 *errmsg = string_sprintf("LDAP option REFERRALS is not \"follow\" "
1056 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1061 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1063 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1064 "library - cannot use \"referrals\"");
1065 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1073 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1075 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1078 while (isspace(*url)) url++;
1082 *errmsg = US"malformed parameter setting precedes LDAP URL";
1083 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1087 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1088 but it seems that not all behave like this. The DN for the user is often the
1089 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1090 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1091 far too complicated. */
1097 for (s = user; *s != 0; s++)
1100 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1105 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1106 ((d >= 'a')? (10 + d - 'a') : d - '0');
1115 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1116 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1117 tcplimit, dereference, (referrals == LDAP_OPT_ON)? "on" : "off");
1119 /* If the request is just to check authentication, some credentials must
1120 be given. The password must not be empty because LDAP binds with an empty
1121 password are considered anonymous, and will succeed on most installations. */
1123 if (search_type == SEARCH_LDAP_AUTH)
1125 if (user == NULL || password == NULL)
1127 *errmsg = US"ldapauth lookups must specify the username and password";
1130 if (password[0] == 0)
1132 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1137 /* Check for valid ldap url starters */
1140 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1141 if (Ustrncmp(p, "://", 3) != 0)
1143 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1144 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1145 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1149 /* No default servers, or URL contains a server name: just one attempt */
1151 if (eldap_default_servers == NULL || p[3] != '/')
1153 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1154 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1158 /* Loop through the default servers until OK or FAIL */
1160 list = eldap_default_servers;
1161 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1165 uschar *colon = Ustrchr(server, ':');
1169 port = Uatoi(colon+1);
1171 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1172 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1174 if (rc != DEFER || defer_break) return rc;
1182 /*************************************************
1183 * Find entry point *
1184 *************************************************/
1186 /* See local README for interface description. The different kinds of search
1187 are handled by a common function, with a flag to differentiate between them.
1188 The handle and filename arguments are not used. */
1191 eldap_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1192 uschar **result, uschar **errmsg, BOOL *do_cache)
1194 /* Keep picky compilers happy */
1195 do_cache = do_cache;
1196 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1200 eldapm_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1201 uschar **result, uschar **errmsg, BOOL *do_cache)
1203 /* Keep picky compilers happy */
1204 do_cache = do_cache;
1205 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1209 eldapdn_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1210 uschar **result, uschar **errmsg, BOOL *do_cache)
1212 /* Keep picky compilers happy */
1213 do_cache = do_cache;
1214 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1218 eldapauth_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1219 uschar **result, uschar **errmsg, BOOL *do_cache)
1221 /* Keep picky compilers happy */
1222 do_cache = do_cache;
1223 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1228 /*************************************************
1229 * Open entry point *
1230 *************************************************/
1232 /* See local README for interface description. */
1235 eldap_open(uschar *filename, uschar **errmsg)
1237 return (void *)(1); /* Just return something non-null */
1242 /*************************************************
1243 * Tidy entry point *
1244 *************************************************/
1246 /* See local README for interface description.
1247 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1252 LDAP_CONNECTION *lcp = NULL;
1255 while ((lcp = ldap_connections) != NULL)
1257 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1259 ldap_unbind(lcp->ld);
1260 ldap_connections = lcp->next;
1266 /*************************************************
1267 * Quote entry point *
1268 *************************************************/
1270 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1271 quoting have to be done: LDAP quoting, and URL quoting. The current
1272 specification is the result of a suggestion by Brian Candler. It recognizes
1275 (1) For text that appears in a search filter, the following escapes are
1276 required (see RFC 2254):
1284 Then the entire filter text must be URL-escaped. This kind of quoting is
1285 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1286 in the input string, because that's a terminator.
1288 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1292 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1293 must be escaped, as must a leading #. Then the string must be URL-quoted.
1294 This type of quoting is implemented by ${quote_ldap_dn:....}.
1296 For URL quoting, the only characters that need not be quoted are the
1301 All the others must be hexified and preceded by %. This includes the
1302 backslashes used for LDAP quoting.
1304 For a DN that is given in the USER parameter for authentication, we need the
1305 same initial quoting as (2) but in this case, the result must NOT be
1306 URL-escaped, because it isn't a URL. The way this is handled is by
1307 de-URL-quoting the text when processing the USER parameter in
1308 control_ldap_search() above. That means that the same quote operator can be
1309 used. This has the additional advantage that spaces in the DN won't cause
1310 parsing problems. For example:
1312 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1314 should be safe if there are spaces in $1.
1318 s the string to be quoted
1319 opt additional option text or NULL if none
1320 only "dn" is recognized
1322 Returns: the processed string or NULL for a bad option
1327 /* The characters in this string, together with alphanumerics, never need
1328 quoting in any way. */
1330 #define ALWAYS_LITERAL "!$'-._"
1332 /* The special characters in this string do not need to be URL-quoted. The set
1333 is a bit larger than the general literals. */
1335 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1337 /* The following macros define the characters that are quoted by quote_ldap and
1338 quote_ldap_dn, respectively. */
1340 #define LDAP_QUOTE "*()\\"
1341 #define LDAP_DN_QUOTE ",+\"\\<>;"
1346 eldap_quote(uschar *s, uschar *opt)
1355 /* Test for a DN quotation. */
1359 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1363 /* Compute how much extra store we need for the string. This doesn't have to be
1364 exact as long as it isn't an underestimate. The worst case is the addition of 5
1365 extra bytes for a single character. This occurs for certain characters in DNs,
1366 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1367 possibly escaped character. The really fast way would be just to test for
1368 non-alphanumerics, but it is probably better to spot a few others that are
1369 never escaped, because if there are no specials at all, we can avoid copying
1372 while ((c = *t++) != 0)
1375 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1377 if (count == 0) return s;
1379 /* Get sufficient store to hold the quoted string */
1381 t = quoted = store_get(len + count + 1);
1383 /* Handle plain quote_ldap */
1387 while ((c = *s++) != 0)
1391 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1393 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1397 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1399 sprintf(CS t, "%%%02X", c);
1404 *t++ = c; /* unquoted character */
1408 /* Handle quote_ldap_dn */
1412 uschar *ss = s + len;
1414 /* Find the last char before any trailing spaces */
1416 while (ss > s && ss[-1] == ' ') ss--;
1418 /* Quote leading spaces and sharps */
1422 if (*s != ' ' && *s != '#') break;
1423 sprintf(CS t, "%%5C%%%02X", *s);
1427 /* Handle the rest of the string, up to the trailing spaces */
1434 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1436 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1437 t += 3; /* fall through to check URL */
1439 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1441 sprintf(CS t, "%%%02X", c);
1446 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1449 /* Handle the trailing spaces */
1453 Ustrncpy(t, "%5C%20", 6);
1458 /* Terminate the new string and return */
1464 #endif /* LOOKUP_LDAP */
1466 /* End of lookups/ldap.c */