1 /* $Cambridge: exim/src/src/lookups/ldap.c,v 1.11 2006/06/27 13:39:01 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}
141 Returns: OK or FAIL or DEFER
142 FAIL is given only if a lookup was performed successfully, but
147 perform_ldap_search(uschar *ldap_url, uschar *server, int s_port, int search_type,
148 uschar **res, uschar **errmsg, BOOL *defer_break, uschar *user, uschar *password,
149 int sizelimit, int timelimit, int tcplimit, int dereference)
151 LDAPURLDesc *ludp = NULL;
152 LDAPMessage *result = NULL;
154 LDAP_CONNECTION *lcp;
156 struct timeval timeout;
157 struct timeval *timeoutptr = NULL;
168 uschar *error1 = NULL; /* string representation of errcode (static) */
169 uschar *error2 = NULL; /* error message from the server */
170 uschar *matched = NULL; /* partially matched DN */
173 int error_yield = DEFER;
175 int rc, ldap_rc, ldap_parse_rc;
180 BOOL attribute_found = FALSE;
184 debug_printf("perform_ldap_search: ldap%s URL = \"%s\" server=%s port=%d "
185 "sizelimit=%d timelimit=%d tcplimit=%d\n",
186 (search_type == SEARCH_LDAP_MULTIPLE)? "m" :
187 (search_type == SEARCH_LDAP_DN)? "dn" :
188 (search_type == SEARCH_LDAP_AUTH)? "auth" : "",
189 ldap_url, server, s_port, sizelimit, timelimit, tcplimit);
191 /* Check if LDAP thinks the URL is a valid LDAP URL. We assume that if the LDAP
192 library that is in use doesn't recognize, say, "ldapi", it will barf here. */
194 if (!ldap_is_ldap_url(CS ldap_url))
196 *errmsg = string_sprintf("ldap_is_ldap_url: not an LDAP url \"%s\"\n",
198 goto RETURN_ERROR_BREAK;
203 if ((rc = ldap_url_parse(CS ldap_url, &ludp)) != 0)
205 *errmsg = string_sprintf("ldap_url_parse: (error %d) parsing \"%s\"\n", rc,
207 goto RETURN_ERROR_BREAK;
210 /* If the host name is empty, take it from the separate argument, if one is
211 given. OpenLDAP 2.0.6 sets an unset hostname to "" rather than empty, but
212 expects NULL later in ldap_init() to mean "default", annoyingly. In OpenLDAP
213 2.0.11 this has changed (it uses NULL). */
215 if ((ludp->lud_host == NULL || ludp->lud_host[0] == 0) && server != NULL)
222 host = US ludp->lud_host;
223 if (host != NULL && host[0] == 0) host = NULL;
224 port = ludp->lud_port;
227 DEBUG(D_lookup) debug_printf("after ldap_url_parse: host=%s port=%d\n",
230 if (port == 0) port = LDAP_PORT; /* Default if none given */
231 sprintf(CS porttext, ":%d", port); /* For messages */
233 /* If the "host name" is actually a path, we are going to connect using a Unix
234 socket, regardless of whether "ldapi" was actually specified or not. This means
235 that a Unix socket can be declared in eldap_default_servers, and "traditional"
236 LDAP queries using just "ldap" can be used ("ldaps" is similarly overridden).
237 The path may start with "/" or it may already be escaped as "%2F" if it was
238 actually declared that way in eldap_default_servers. (I did it that way the
239 first time.) If the host name is not a path, the use of "ldapi" causes an
240 error, except in the default case. (But lud_scheme doesn't seem to exist in
245 if ((host[0] == '/' || Ustrncmp(host, "%2F", 3) == 0))
248 porttext[0] = 0; /* Remove port from messages */
251 #if defined LDAP_LIB_OPENLDAP2
252 else if (strncmp(ludp->lud_scheme, "ldapi", 5) == 0)
254 *errmsg = string_sprintf("ldapi requires an absolute path (\"%s\" given)",
261 /* Count the attributes; we need this later to tell us how to format results */
263 for (attrp = USS ludp->lud_attrs; attrp != NULL && *attrp != NULL; attrp++)
266 /* See if we can find a cached connection to this host. The port is not
267 relevant for ldapi. The host name pointer is set to NULL if no host was given
268 (implying the library default), rather than to the empty string. Note that in
269 this case, there is no difference between ldap and ldapi. */
271 for (lcp = ldap_connections; lcp != NULL; lcp = lcp->next)
273 if ((host == NULL) != (lcp->host == NULL) ||
274 (host != NULL && strcmpic(lcp->host, host) != 0))
276 if (ldapi || port == lcp->port) break;
279 /* Use this network timeout in any requests. */
283 timeout.tv_sec = tcplimit;
285 timeoutptr = &timeout;
288 /* If no cached connection found, we must open a connection to the server. If
289 the server name is actually an absolute path, we set ldapi=TRUE above. This
290 requests connection via a Unix socket. However, as far as I know, only OpenLDAP
291 supports the use of sockets, and the use of ldap_initialize(). */
298 /* --------------------------- OpenLDAP ------------------------ */
300 /* There seems to be a preference under OpenLDAP for ldap_initialize()
301 instead of ldap_init(), though I have as yet been unable to find
302 documentation that says this. (OpenLDAP documentation is sparse to
303 non-existent). So we handle OpenLDAP differently here. Also, support for
304 ldapi seems to be OpenLDAP-only at present. */
306 #ifdef LDAP_LIB_OPENLDAP2
308 /* We now need an empty string for the default host. Get some store in which
309 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
310 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
311 than the host name + "ldaps:///" plus : and a port number, say 20 + the
312 length of the host name. What we get should accommodate both, easily. */
314 uschar *shost = (host == NULL)? US"" : host;
315 uschar *init_url = store_get(20 + 3 * Ustrlen(shost));
318 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
319 contain the path name, with slashes escaped as %2F. */
324 init_ptr = init_url + 8;
325 Ustrcpy(init_url, "ldapi://");
326 while ((ch = *shost++) != 0)
330 Ustrncpy(init_ptr, "%2F", 3);
333 else *init_ptr++ = ch;
338 /* This is not an ldapi call. Just build a URI with the protocol type, host
343 init_ptr = Ustrchr(ldap_url, '/');
344 Ustrncpy(init_url, ldap_url, init_ptr - ldap_url);
345 init_ptr = init_url + (init_ptr - ldap_url);
346 sprintf(CS init_ptr, "//%s:%d/", shost, port);
349 /* Call ldap_initialize() and check the result */
351 DEBUG(D_lookup) debug_printf("ldap_initialize with URL %s\n", init_url);
352 rc = ldap_initialize(&ld, CS init_url);
353 if (rc != LDAP_SUCCESS)
355 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
359 store_reset(init_url); /* Might as well save memory when we can */
362 /* ------------------------- Not OpenLDAP ---------------------- */
364 /* For libraries other than OpenLDAP, use ldap_init(). */
366 #else /* LDAP_LIB_OPENLDAP2 */
367 ld = ldap_init(CS host, port);
368 #endif /* LDAP_LIB_OPENLDAP2 */
370 /* -------------------------------------------------------------- */
373 /* Handle failure to initialize */
377 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
378 host, porttext, strerror(errno));
382 /* Set the TCP connect time limit if available. This is something that is
383 in Netscape SDK v4.1; I don't know about other libraries. */
385 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
388 int timeout1000 = tcplimit*1000;
389 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
393 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
394 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)¬imeout);
398 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
400 #ifdef LDAP_OPT_NETWORK_TIMEOUT
402 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
405 /* I could not get TLS to work until I set the version to 3. That version
406 seems to be the default nowadays. The RFC is dated 1997, so I would hope
407 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
408 been set, go for v3 if we can. */
410 if (eldap_version < 0)
413 eldap_version = LDAP_VERSION3;
419 #ifdef LDAP_OPT_PROTOCOL_VERSION
420 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
423 DEBUG(D_lookup) debug_printf("initialized for LDAP (v%d) server %s%s\n",
424 eldap_version, host, porttext);
426 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
427 for "ldaps" and soft otherwise. */
429 #ifdef LDAP_OPT_X_TLS
433 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
435 tls_option = LDAP_OPT_X_TLS_HARD;
436 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_HARD set\n");
440 tls_option = LDAP_OPT_X_TLS_TRY;
441 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_TRY set\n");
443 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
445 #endif /* LDAP_OPT_X_TLS */
447 /* Now add this connection to the chain of cached connections */
449 lcp = store_get(sizeof(LDAP_CONNECTION));
450 lcp->host = (host == NULL)? NULL : string_copy(host);
453 lcp->password = NULL;
456 lcp->next = ldap_connections;
457 ldap_connections = lcp;
460 /* Found cached connection */
465 debug_printf("re-using cached connection to LDAP server %s%s\n",
469 /* Bind with the user/password supplied, or an anonymous bind if these values
470 are NULL, unless a cached connection is already bound with the same values. */
473 (lcp->user == NULL && user != NULL) ||
474 (lcp->user != NULL && user == NULL) ||
475 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
476 (lcp->password == NULL && password != NULL) ||
477 (lcp->password != NULL && password == NULL) ||
478 (lcp->password != NULL && password != NULL &&
479 Ustrcmp(lcp->password, password) != 0))
481 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
482 (lcp->bound)? "re-" : "", user, password);
483 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
486 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
487 "%s%s - ldap_bind() returned -1", host, porttext);
491 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
493 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
494 "%s%s - LDAP error: %s", host, porttext,
495 rc == -1 ? "result retrieval failed" : "timeout" );
500 rc = ldap_result2error( lcp->ld, result, 0 );
502 /* Invalid credentials when just checking credentials returns FAIL. This
503 stops any further servers being tried. */
505 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
508 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
510 goto RETURN_ERROR_NOMSG;
513 /* Otherwise we have a problem that doesn't stop further servers from being
516 if (rc != LDAP_SUCCESS)
518 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
519 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
523 /* Successful bind */
526 lcp->user = (user == NULL)? NULL : string_copy(user);
527 lcp->password = (password == NULL)? NULL : string_copy(password);
529 ldap_msgfree(result);
533 /* If we are just checking credentials, return OK. */
535 if (search_type == SEARCH_LDAP_AUTH)
537 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
541 /* Before doing the search, set the time and size limits (if given). Here again
542 the different implementations of LDAP have chosen to do things differently. */
544 #if defined(LDAP_OPT_SIZELIMIT)
545 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
546 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
548 lcp->ld->ld_sizelimit = sizelimit;
549 lcp->ld->ld_timelimit = timelimit;
552 /* Similarly for dereferencing aliases. Don't know if this is possible on
553 an LDAP library without LDAP_OPT_DEREF. */
555 #if defined(LDAP_OPT_DEREF)
556 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
559 /* Start the search on the server. */
561 DEBUG(D_lookup) debug_printf("Start search\n");
563 msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
568 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
570 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
571 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
572 ldap_err2string(err));
575 *errmsg = string_sprintf("ldap_search failed");
581 /* Loop to pick up results as they come in, setting a timeout if one was
584 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
585 LDAP_RES_SEARCH_ENTRY)
589 DEBUG(D_lookup) debug_printf("ldap_result loop\n");
591 for(e = ldap_first_entry(lcp->ld, result);
593 e = ldap_next_entry(lcp->ld, e))
596 BOOL insert_space = FALSE;
598 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
600 rescount++; /* Count results */
602 /* Results for multiple entries values are separated by newlines. */
604 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
606 /* Get the DN from the last result. */
608 new_dn = US ldap_get_dn(lcp->ld, e);
613 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
615 #else /* OPENLDAP 1, UMich, Solaris */
623 /* If the data we want is actually the DN rather than any attribute values,
624 (an "ldapdn" search) add it to the data string. If there are multiple
625 entries, the DNs will be concatenated, but we test for this case below, as
626 for SEARCH_LDAP_SINGLE, and give an error. */
628 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
629 { /* condition, because of the else */
630 if (new_dn != NULL) /* below, that's for the first only */
632 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
634 attribute_found = TRUE;
638 /* Otherwise, loop through the entry, grabbing attribute values. If there's
639 only one attribute being retrieved, no attribute name is given, and the
640 result is not quoted. Multiple values are separated by (comma, space).
641 If more than one attribute is being retrieved, the data is given as a
642 sequence of name=value pairs, with the value always in quotes. If there are
643 multiple values, they are given within the quotes, comma separated. */
645 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
647 attr = US ldap_next_attribute(lcp->ld, e, ber))
651 /* Get array of values for this attribute. */
653 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
659 data = string_cat(data, &size, &ptr, US" ", 1);
662 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
663 data = string_cat(data, &size, &ptr, US"=\"", 2);
666 while (*values != NULL)
668 uschar *value = *values;
669 int len = Ustrlen(value);
671 DEBUG(D_lookup) debug_printf("LDAP attr loop %s:%s\n", attr, value);
673 if (values != firstval)
674 data = string_cat(data, &size, &ptr, US", ", 2);
676 /* For multiple attributes, the data is in quotes. We must escape
677 internal quotes, backslashes, newlines. */
682 for (j = 0; j < len; j++)
684 if (value[j] == '\n')
685 data = string_cat(data, &size, &ptr, US"\\n", 2);
688 if (value[j] == '\"' || value[j] == '\\')
689 data = string_cat(data, &size, &ptr, US"\\", 1);
690 data = string_cat(data, &size, &ptr, value+j, 1);
695 /* For single attributes, copy the value verbatim */
697 else data = string_cat(data, &size, &ptr, value, len);
699 /* Move on to the next value */
702 attribute_found = TRUE;
705 /* Closing quote at the end of the data for a named attribute. */
708 data = string_cat(data, &size, &ptr, US"\"", 1);
710 /* Free the values */
712 ldap_value_free(CSS firstval);
716 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
718 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
719 to be freed. UMich LDAP stores them in static storage and does not require
724 } /* End "for" loop for extracting attributes from an entry */
725 } /* End "for" loop for extracting entries from a result */
727 /* Free the result */
729 ldap_msgfree(result);
731 } /* End "while" loop for multiple results */
733 /* Terminate the dynamic string that we have built and reclaim unused store */
738 store_reset(data + ptr + 1);
741 /* Copy the last dn into eldap_dn */
745 eldap_dn = string_copy(dn);
746 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
748 #else /* OPENLDAP 1, UMich, Solaris */
753 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
757 *errmsg = US"ldap_result timed out";
761 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
762 provide you with a message". Other error states seem to exist where
763 ldap_result() didn't give us any message from the server at all, leaving result
764 set to NULL. Apparently, "the error parameters of the LDAP session handle will
765 be set accordingly". That's the best we can do to retrieve an error status; we
766 can't use functions like ldap_result2error because they parse a message from
767 the server, which we didn't get.
769 Annoyingly, the different implementations of LDAP have gone for different
770 methods of handling error codes and generating error messages. */
772 if (rc == -1 || result == NULL)
775 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
777 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
778 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
779 *errmsg = string_sprintf("ldap_result failed: %d, %s",
780 err, ldap_err2string(err));
782 #elif defined LDAP_LIB_NETSCAPE
783 /* Dubious (surely 'matched' is spurious here?) */
784 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
785 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
787 #else /* UMich LDAP aka OpenLDAP 1.x */
788 *errmsg = string_sprintf("ldap_result failed: %d, %s",
789 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
795 /* A return code that isn't -1 doesn't necessarily mean there were no problems
796 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
797 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
798 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
799 we don't provide that functionality when we can't. :-) */
801 if (rc != LDAP_RES_SEARCH_RESULT
802 #ifdef LDAP_RES_SEARCH_REFERENCE
803 && rc != LDAP_RES_SEARCH_REFERENCE
807 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
811 /* We have a result message from the server. This doesn't yet mean all is well.
812 We need to parse the message to find out exactly what's happened. */
814 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
816 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
817 CSS &error2, NULL, NULL, 0);
818 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
819 if (ldap_parse_rc < 0 &&
820 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
821 #ifdef LDAP_RES_SEARCH_REFERENCE
822 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
826 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
829 error1 = US ldap_err2string(rc);
831 #elif defined LDAP_LIB_NETSCAPE
832 /* Dubious (it doesn't reference 'result' at all!) */
833 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
835 #else /* UMich LDAP aka OpenLDAP 1.x */
836 rc = ldap_result2error(lcp->ld, result, 0);
837 error1 = ldap_err2string(rc);
838 error2 = lcp->ld->ld_error;
839 matched = lcp->ld->ld_matched;
842 /* Process the status as follows:
844 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
845 truncated result list.
847 (2) 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 (3) 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)
860 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
862 (error1 != NULL)? error1 : US"",
863 (error2 != NULL && error2[0] != 0)? US"/" : US"",
864 (error2 != NULL)? error2 : US"",
865 (matched != NULL && matched[0] != 0)? US"/" : US"",
866 (matched != NULL)? matched : US"");
868 #if defined LDAP_NAME_ERROR
869 if (LDAP_NAME_ERROR(rc))
870 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
873 if (rc == LDAP_NO_SUCH_OBJECT)
877 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
883 /* The search succeeded. Check if we have too many results */
885 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
887 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
888 "(filter not specific enough?)", rescount);
889 goto RETURN_ERROR_BREAK;
892 /* Check if we have too few (zero) entries */
896 *errmsg = string_sprintf("LDAP search: no results");
898 goto RETURN_ERROR_BREAK;
901 /* If an entry was found, but it had no attributes, we behave as if no entries
902 were found, that is, the lookup failed. */
904 if (!attribute_found)
906 *errmsg = US"LDAP search: found no attributes";
911 /* Otherwise, it's all worked */
913 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
917 if (result != NULL) ldap_msgfree(result);
918 ldap_free_urldesc(ludp);
927 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
930 if (result != NULL) ldap_msgfree(result);
931 if (ludp != NULL) ldap_free_urldesc(ludp);
933 #if defined LDAP_LIB_OPENLDAP2
934 if (error2 != NULL) ldap_memfree(error2);
935 if (matched != NULL) ldap_memfree(matched);
943 /*************************************************
944 * Internal search control function *
945 *************************************************/
947 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
948 and eldapm_find() with a difference in the "search_type" argument. It controls
949 calls to perform_ldap_search() which actually does the work. We call that
950 repeatedly for certain types of defer in the case when the URL contains no host
951 name and eldap_default_servers is set to a list of servers to try. This gives
952 more control than just passing over a list of hosts to ldap_open() because it
953 handles other kinds of defer as well as just a failure to open. Note that the
954 URL is defined to contain either zero or one "hostport" only.
956 Parameter data in addition to the URL can be passed as preceding text in the
957 string, as items of the form XXX=yyy. The URL itself can be detected because it
958 must begin "ldapx://", where x is empty, s, or i.
961 ldap_url the URL to be looked up, optionally preceded by other parameter
963 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
964 SEARCH_LDAP_SINGLE allows values from one entry only
965 SEARCH_LDAP_DN gets the DN from one entry
966 res set to point at the result
967 errmsg set to point a message if result is not OK
969 Returns: OK or FAIL or DEFER
973 control_ldap_search(uschar *ldap_url, int search_type, uschar **res,
976 BOOL defer_break = FALSE;
977 int timelimit = LDAP_NO_LIMIT;
978 int sizelimit = LDAP_NO_LIMIT;
980 int dereference = LDAP_DEREF_NEVER;
982 uschar *url = ldap_url;
985 uschar *password = NULL;
986 uschar *server, *list;
989 while (isspace(*url)) url++;
991 /* Until the string begins "ldap", search for the other parameter settings that
992 are recognized. They are of the form NAME=VALUE, with the value being
993 optionally double-quoted. There must still be a space after it, however. No
994 NAME has the value "ldap". */
996 while (strncmpic(url, US"ldap", 4) != 0)
999 while (*url != 0 && *url != '=') url++;
1004 namelen = ++url - name;
1005 value = string_dequote(&url);
1008 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1009 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1010 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1011 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1012 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1013 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1015 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1017 #ifdef LDAP_OPT_DEREF
1018 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1020 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1021 else if (strcmpic(value, US"searching") == 0)
1022 dereference = LDAP_DEREF_SEARCHING;
1023 else if (strcmpic(value, US"finding") == 0)
1024 dereference = LDAP_DEREF_FINDING;
1025 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1028 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1030 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1031 "library - cannot use \"dereference\"");
1032 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1041 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1043 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1046 while (isspace(*url)) url++;
1050 *errmsg = US"malformed parameter setting precedes LDAP URL";
1051 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1055 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1056 but it seems that not all behave like this. The DN for the user is often the
1057 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1058 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1059 far too complicated. */
1065 for (s = user; *s != 0; s++)
1068 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1073 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1074 ((d >= 'a')? (10 + d - 'a') : d - '0');
1083 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1084 "dereference=%d\n", user, password, sizelimit, timelimit, tcplimit,
1087 /* If the request is just to check authentication, some credentials must
1088 be given. The password must not be empty because LDAP binds with an empty
1089 password are considered anonymous, and will succeed on most installations. */
1091 if (search_type == SEARCH_LDAP_AUTH)
1093 if (user == NULL || password == NULL)
1095 *errmsg = US"ldapauth lookups must specify the username and password";
1098 if (password[0] == 0)
1100 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1105 /* Check for valid ldap url starters */
1108 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1109 if (Ustrncmp(p, "://", 3) != 0)
1111 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1112 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1113 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1117 /* No default servers, or URL contains a server name: just one attempt */
1119 if (eldap_default_servers == NULL || p[3] != '/')
1121 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1122 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference);
1125 /* Loop through the default servers until OK or FAIL */
1127 list = eldap_default_servers;
1128 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1132 uschar *colon = Ustrchr(server, ':');
1136 port = Uatoi(colon+1);
1138 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1139 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference);
1140 if (rc != DEFER || defer_break) return rc;
1148 /*************************************************
1149 * Find entry point *
1150 *************************************************/
1152 /* See local README for interface description. The different kinds of search
1153 are handled by a common function, with a flag to differentiate between them.
1154 The handle and filename arguments are not used. */
1157 eldap_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1158 uschar **result, uschar **errmsg, BOOL *do_cache)
1160 /* Keep picky compilers happy */
1161 do_cache = do_cache;
1162 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1166 eldapm_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1167 uschar **result, uschar **errmsg, BOOL *do_cache)
1169 /* Keep picky compilers happy */
1170 do_cache = do_cache;
1171 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1175 eldapdn_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1176 uschar **result, uschar **errmsg, BOOL *do_cache)
1178 /* Keep picky compilers happy */
1179 do_cache = do_cache;
1180 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1184 eldapauth_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1185 uschar **result, uschar **errmsg, BOOL *do_cache)
1187 /* Keep picky compilers happy */
1188 do_cache = do_cache;
1189 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1194 /*************************************************
1195 * Open entry point *
1196 *************************************************/
1198 /* See local README for interface description. */
1201 eldap_open(uschar *filename, uschar **errmsg)
1203 return (void *)(1); /* Just return something non-null */
1208 /*************************************************
1209 * Tidy entry point *
1210 *************************************************/
1212 /* See local README for interface description.
1213 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1218 LDAP_CONNECTION *lcp = NULL;
1221 while ((lcp = ldap_connections) != NULL)
1223 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1225 ldap_unbind(lcp->ld);
1226 ldap_connections = lcp->next;
1232 /*************************************************
1233 * Quote entry point *
1234 *************************************************/
1236 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1237 quoting have to be done: LDAP quoting, and URL quoting. The current
1238 specification is the result of a suggestion by Brian Candler. It recognizes
1241 (1) For text that appears in a search filter, the following escapes are
1242 required (see RFC 2254):
1250 Then the entire filter text must be URL-escaped. This kind of quoting is
1251 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1252 in the input string, because that's a terminator.
1254 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1258 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1259 must be escaped, as must a leading #. Then the string must be URL-quoted.
1260 This type of quoting is implemented by ${quote_ldap_dn:....}.
1262 For URL quoting, the only characters that need not be quoted are the
1267 All the others must be hexified and preceded by %. This includes the
1268 backslashes used for LDAP quoting.
1270 For a DN that is given in the USER parameter for authentication, we need the
1271 same initial quoting as (2) but in this case, the result must NOT be
1272 URL-escaped, because it isn't a URL. The way this is handled is by
1273 de-URL-quoting the text when processing the USER parameter in
1274 control_ldap_search() above. That means that the same quote operator can be
1275 used. This has the additional advantage that spaces in the DN won't cause
1276 parsing problems. For example:
1278 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1280 should be safe if there are spaces in $1.
1284 s the string to be quoted
1285 opt additional option text or NULL if none
1286 only "dn" is recognized
1288 Returns: the processed string or NULL for a bad option
1293 /* The characters in this string, together with alphanumerics, never need
1294 quoting in any way. */
1296 #define ALWAYS_LITERAL "!$'-._"
1298 /* The special characters in this string do not need to be URL-quoted. The set
1299 is a bit larger than the general literals. */
1301 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1303 /* The following macros define the characters that are quoted by quote_ldap and
1304 quote_ldap_dn, respectively. */
1306 #define LDAP_QUOTE "*()\\"
1307 #define LDAP_DN_QUOTE ",+\"\\<>;"
1312 eldap_quote(uschar *s, uschar *opt)
1321 /* Test for a DN quotation. */
1325 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1329 /* Compute how much extra store we need for the string. This doesn't have to be
1330 exact as long as it isn't an underestimate. The worst case is the addition of 5
1331 extra bytes for a single character. This occurs for certain characters in DNs,
1332 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1333 possibly escaped character. The really fast way would be just to test for
1334 non-alphanumerics, but it is probably better to spot a few others that are
1335 never escaped, because if there are no specials at all, we can avoid copying
1338 while ((c = *t++) != 0)
1341 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1343 if (count == 0) return s;
1345 /* Get sufficient store to hold the quoted string */
1347 t = quoted = store_get(len + count + 1);
1349 /* Handle plain quote_ldap */
1353 while ((c = *s++) != 0)
1357 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1359 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1363 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1365 sprintf(CS t, "%%%02X", c);
1370 *t++ = c; /* unquoted character */
1374 /* Handle quote_ldap_dn */
1378 uschar *ss = s + len;
1380 /* Find the last char before any trailing spaces */
1382 while (ss > s && ss[-1] == ' ') ss--;
1384 /* Quote leading spaces and sharps */
1388 if (*s != ' ' && *s != '#') break;
1389 sprintf(CS t, "%%5C%%%02X", *s);
1393 /* Handle the rest of the string, up to the trailing spaces */
1400 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1402 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1403 t += 3; /* fall through to check URL */
1405 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1407 sprintf(CS t, "%%%02X", c);
1412 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1415 /* Handle the trailing spaces */
1419 Ustrncpy(t, "%5C%20", 6);
1424 /* Terminate the new string and return */
1430 #endif /* LOOKUP_LDAP */
1432 /* End of lookups/ldap.c */