1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2012 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Many thanks to Stuart Lynne for contributing the original code for this
9 driver. Further contibutions from Michael Haardt, Brian Candler, Barry
10 Pederson, Peter Savitch and Christian Kellner. Particular thanks to Brian for
11 researching how to handle the different kinds of error. */
15 #include "lf_functions.h"
18 /* Include LDAP headers. The code below uses some "old" LDAP interfaces that
19 are deprecated in OpenLDAP. I don't know their status in other LDAP
20 implementations. LDAP_DEPRECATED causes their prototypes to be defined in
23 #define LDAP_DEPRECATED 1
29 /* Annoyingly, the different LDAP libraries handle errors in different ways,
30 and some other things too. There doesn't seem to be an automatic way of
31 distinguishing between them. Local/Makefile should contain a setting of
32 LDAP_LIB_TYPE, which in turn causes appropriate macros to be defined for the
33 different kinds. Those that matter are:
36 LDAP_LIB_SOLARIS with synonym LDAP_LIB_SOLARIS7
39 These others may be defined, but are in fact the default, so are not tested:
45 #if defined(LDAP_LIB_SOLARIS7) && ! defined(LDAP_LIB_SOLARIS)
46 #define LDAP_LIB_SOLARIS
50 /* Just in case LDAP_NO_LIMIT is not defined by some of these libraries. */
53 #define LDAP_NO_LIMIT 0
57 /* Just in case LDAP_DEREF_NEVER is not defined */
59 #ifndef LDAP_DEREF_NEVER
60 #define LDAP_DEREF_NEVER 0
64 /* Four types of LDAP search are implemented */
66 #define SEARCH_LDAP_MULTIPLE 0 /* Get attributes from multiple entries */
67 #define SEARCH_LDAP_SINGLE 1 /* Get attributes from one entry only */
68 #define SEARCH_LDAP_DN 2 /* Get just the DN from one entry */
69 #define SEARCH_LDAP_AUTH 3 /* Just checking for authentication */
71 /* In all 4 cases, the DN is left in $ldap_dn (which post-dates the
72 SEARCH_LDAP_DN lookup). */
75 /* Structure and anchor for caching connections. */
77 typedef struct ldap_connection {
78 struct ldap_connection *next;
87 static LDAP_CONNECTION *ldap_connections = NULL;
91 /*************************************************
92 * Internal search function *
93 *************************************************/
95 /* This is the function that actually does the work. It is called (indirectly
96 via control_ldap_search) from eldap_find(), eldapauth_find(), eldapdn_find(),
97 and eldapm_find(), with a difference in the "search_type" argument.
99 The case of eldapauth_find() is special in that all it does is do
100 authentication, returning OK or FAIL as appropriate. This isn't used as a
101 lookup. Instead, it is called from expand.c as an expansion condition test.
103 The DN from a successful lookup is placed in $ldap_dn. This feature postdates
104 the provision of the SEARCH_LDAP_DN facility for returning just the DN as the
108 ldap_url the URL to be looked up
109 server server host name, when URL contains none
110 s_port server port, used when URL contains no name
111 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
112 SEARCH_LDAP_SINGLE allows values from one entry only
113 SEARCH_LDAP_DN gets the DN from one entry
114 res set to point at the result (not used for ldapauth)
115 errmsg set to point a message if result is not OK
116 defer_break set TRUE if no more servers to be tried after a DEFER
117 user user name for authentication, or NULL
118 password password for authentication, or NULL
119 sizelimit max number of entries returned, or 0 for no limit
120 timelimit max time to wait, or 0 for no limit
121 tcplimit max time for network activity, e.g. connect, or 0 for OS default
122 deference the dereference option, which is one of
123 LDAP_DEREF_{NEVER,SEARCHING,FINDING,ALWAYS}
124 referrals the referral option, which is LDAP_OPT_ON or LDAP_OPT_OFF
126 Returns: OK or FAIL or DEFER
127 FAIL is given only if a lookup was performed successfully, but
132 perform_ldap_search(uschar *ldap_url, uschar *server, int s_port, int search_type,
133 uschar **res, uschar **errmsg, BOOL *defer_break, uschar *user, uschar *password,
134 int sizelimit, int timelimit, int tcplimit, int dereference, void *referrals)
136 LDAPURLDesc *ludp = NULL;
137 LDAPMessage *result = NULL;
139 LDAP_CONNECTION *lcp;
141 struct timeval timeout;
142 struct timeval *timeoutptr = NULL;
153 uschar *error1 = NULL; /* string representation of errcode (static) */
154 uschar *error2 = NULL; /* error message from the server */
155 uschar *matched = NULL; /* partially matched DN */
158 int error_yield = DEFER;
160 int rc, ldap_rc, ldap_parse_rc;
165 BOOL attribute_found = FALSE;
169 debug_printf("perform_ldap_search: ldap%s URL = \"%s\" server=%s port=%d "
170 "sizelimit=%d timelimit=%d tcplimit=%d\n",
171 (search_type == SEARCH_LDAP_MULTIPLE)? "m" :
172 (search_type == SEARCH_LDAP_DN)? "dn" :
173 (search_type == SEARCH_LDAP_AUTH)? "auth" : "",
174 ldap_url, server, s_port, sizelimit, timelimit, tcplimit);
176 /* Check if LDAP thinks the URL is a valid LDAP URL. We assume that if the LDAP
177 library that is in use doesn't recognize, say, "ldapi", it will barf here. */
179 if (!ldap_is_ldap_url(CS ldap_url))
181 *errmsg = string_sprintf("ldap_is_ldap_url: not an LDAP url \"%s\"\n",
183 goto RETURN_ERROR_BREAK;
188 if ((rc = ldap_url_parse(CS ldap_url, &ludp)) != 0)
190 *errmsg = string_sprintf("ldap_url_parse: (error %d) parsing \"%s\"\n", rc,
192 goto RETURN_ERROR_BREAK;
195 /* If the host name is empty, take it from the separate argument, if one is
196 given. OpenLDAP 2.0.6 sets an unset hostname to "" rather than empty, but
197 expects NULL later in ldap_init() to mean "default", annoyingly. In OpenLDAP
198 2.0.11 this has changed (it uses NULL). */
200 if ((ludp->lud_host == NULL || ludp->lud_host[0] == 0) && server != NULL)
207 host = US ludp->lud_host;
208 if (host != NULL && host[0] == 0) host = NULL;
209 port = ludp->lud_port;
212 DEBUG(D_lookup) debug_printf("after ldap_url_parse: host=%s port=%d\n",
215 if (port == 0) port = LDAP_PORT; /* Default if none given */
216 sprintf(CS porttext, ":%d", port); /* For messages */
218 /* If the "host name" is actually a path, we are going to connect using a Unix
219 socket, regardless of whether "ldapi" was actually specified or not. This means
220 that a Unix socket can be declared in eldap_default_servers, and "traditional"
221 LDAP queries using just "ldap" can be used ("ldaps" is similarly overridden).
222 The path may start with "/" or it may already be escaped as "%2F" if it was
223 actually declared that way in eldap_default_servers. (I did it that way the
224 first time.) If the host name is not a path, the use of "ldapi" causes an
225 error, except in the default case. (But lud_scheme doesn't seem to exist in
230 if ((host[0] == '/' || Ustrncmp(host, "%2F", 3) == 0))
233 porttext[0] = 0; /* Remove port from messages */
236 #if defined LDAP_LIB_OPENLDAP2
237 else if (strncmp(ludp->lud_scheme, "ldapi", 5) == 0)
239 *errmsg = string_sprintf("ldapi requires an absolute path (\"%s\" given)",
246 /* Count the attributes; we need this later to tell us how to format results */
248 for (attrp = USS ludp->lud_attrs; attrp != NULL && *attrp != NULL; attrp++)
251 /* See if we can find a cached connection to this host. The port is not
252 relevant for ldapi. The host name pointer is set to NULL if no host was given
253 (implying the library default), rather than to the empty string. Note that in
254 this case, there is no difference between ldap and ldapi. */
256 for (lcp = ldap_connections; lcp != NULL; lcp = lcp->next)
258 if ((host == NULL) != (lcp->host == NULL) ||
259 (host != NULL && strcmpic(lcp->host, host) != 0))
261 if (ldapi || port == lcp->port) break;
264 /* Use this network timeout in any requests. */
268 timeout.tv_sec = tcplimit;
270 timeoutptr = &timeout;
273 /* If no cached connection found, we must open a connection to the server. If
274 the server name is actually an absolute path, we set ldapi=TRUE above. This
275 requests connection via a Unix socket. However, as far as I know, only OpenLDAP
276 supports the use of sockets, and the use of ldap_initialize(). */
283 /* --------------------------- OpenLDAP ------------------------ */
285 /* There seems to be a preference under OpenLDAP for ldap_initialize()
286 instead of ldap_init(), though I have as yet been unable to find
287 documentation that says this. (OpenLDAP documentation is sparse to
288 non-existent). So we handle OpenLDAP differently here. Also, support for
289 ldapi seems to be OpenLDAP-only at present. */
291 #ifdef LDAP_LIB_OPENLDAP2
293 /* We now need an empty string for the default host. Get some store in which
294 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
295 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
296 than the host name + "ldaps:///" plus : and a port number, say 20 + the
297 length of the host name. What we get should accommodate both, easily. */
299 uschar *shost = (host == NULL)? US"" : host;
300 uschar *init_url = store_get(20 + 3 * Ustrlen(shost));
303 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
304 contain the path name, with slashes escaped as %2F. */
309 init_ptr = init_url + 8;
310 Ustrcpy(init_url, "ldapi://");
311 while ((ch = *shost++) != 0)
315 Ustrncpy(init_ptr, "%2F", 3);
318 else *init_ptr++ = ch;
323 /* This is not an ldapi call. Just build a URI with the protocol type, host
328 init_ptr = Ustrchr(ldap_url, '/');
329 Ustrncpy(init_url, ldap_url, init_ptr - ldap_url);
330 init_ptr = init_url + (init_ptr - ldap_url);
331 sprintf(CS init_ptr, "//%s:%d/", shost, port);
334 /* Call ldap_initialize() and check the result */
336 DEBUG(D_lookup) debug_printf("ldap_initialize with URL %s\n", init_url);
337 rc = ldap_initialize(&ld, CS init_url);
338 if (rc != LDAP_SUCCESS)
340 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
344 store_reset(init_url); /* Might as well save memory when we can */
347 /* ------------------------- Not OpenLDAP ---------------------- */
349 /* For libraries other than OpenLDAP, use ldap_init(). */
351 #else /* LDAP_LIB_OPENLDAP2 */
352 ld = ldap_init(CS host, port);
353 #endif /* LDAP_LIB_OPENLDAP2 */
355 /* -------------------------------------------------------------- */
358 /* Handle failure to initialize */
362 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
363 host, porttext, strerror(errno));
367 /* Set the TCP connect time limit if available. This is something that is
368 in Netscape SDK v4.1; I don't know about other libraries. */
370 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
373 int timeout1000 = tcplimit*1000;
374 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
378 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
379 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)¬imeout);
383 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
385 #ifdef LDAP_OPT_NETWORK_TIMEOUT
387 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
390 /* I could not get TLS to work until I set the version to 3. That version
391 seems to be the default nowadays. The RFC is dated 1997, so I would hope
392 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
393 been set, go for v3 if we can. */
395 if (eldap_version < 0)
398 eldap_version = LDAP_VERSION3;
404 #ifdef LDAP_OPT_PROTOCOL_VERSION
405 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
408 DEBUG(D_lookup) debug_printf("initialized for LDAP (v%d) server %s%s\n",
409 eldap_version, host, porttext);
411 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
412 for "ldaps" and soft otherwise. */
414 #ifdef LDAP_OPT_X_TLS
418 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
420 tls_option = LDAP_OPT_X_TLS_HARD;
421 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_HARD set\n");
425 tls_option = LDAP_OPT_X_TLS_TRY;
426 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_TRY set\n");
428 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
430 #endif /* LDAP_OPT_X_TLS */
432 #ifdef LDAP_OPT_X_TLS_CACERTFILE
433 if (eldap_ca_cert_file != NULL)
435 ldap_set_option(ld, LDAP_OPT_X_TLS_CACERTFILE, eldap_ca_cert_file);
438 #ifdef LDAP_OPT_X_TLS_CACERTDIR
439 if (eldap_ca_cert_dir != NULL)
441 ldap_set_option(ld, LDAP_OPT_X_TLS_CACERTDIR, eldap_ca_cert_dir);
444 #ifdef LDAP_OPT_X_TLS_CERTFILE
445 if (eldap_cert_file != NULL)
447 ldap_set_option(ld, LDAP_OPT_X_TLS_CERTFILE, eldap_cert_file);
450 #ifdef LDAP_OPT_X_TLS_KEYFILE
451 if (eldap_cert_key != NULL)
453 ldap_set_option(ld, LDAP_OPT_X_TLS_KEYFILE, eldap_cert_key);
456 #ifdef LDAP_OPT_X_TLS_CIPHER_SUITE
457 if (eldap_cipher_suite != NULL)
459 ldap_set_option(ld, LDAP_OPT_X_TLS_CIPHER_SUITE, eldap_cipher_suite);
462 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
463 if (eldap_require_cert != NULL)
465 int cert_option = LDAP_OPT_X_TLS_NEVER;
466 if (Ustrcmp(eldap_require_cert, "hard") == 0)
468 cert_option = LDAP_OPT_X_TLS_HARD;
470 else if (Ustrcmp(eldap_require_cert, "demand") == 0)
472 cert_option = LDAP_OPT_X_TLS_DEMAND;
474 else if (Ustrcmp(eldap_require_cert, "allow") == 0)
476 cert_option = LDAP_OPT_X_TLS_ALLOW;
478 else if (Ustrcmp(eldap_require_cert, "try") == 0)
480 cert_option = LDAP_OPT_X_TLS_TRY;
482 ldap_set_option(ld, LDAP_OPT_X_TLS_REQUIRE_CERT, &cert_option);
486 /* Now add this connection to the chain of cached connections */
488 lcp = store_get(sizeof(LDAP_CONNECTION));
489 lcp->host = (host == NULL)? NULL : string_copy(host);
492 lcp->password = NULL;
495 lcp->next = ldap_connections;
496 ldap_connections = lcp;
499 /* Found cached connection */
504 debug_printf("re-using cached connection to LDAP server %s%s\n",
508 /* Bind with the user/password supplied, or an anonymous bind if these values
509 are NULL, unless a cached connection is already bound with the same values. */
512 (lcp->user == NULL && user != NULL) ||
513 (lcp->user != NULL && user == NULL) ||
514 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
515 (lcp->password == NULL && password != NULL) ||
516 (lcp->password != NULL && password == NULL) ||
517 (lcp->password != NULL && password != NULL &&
518 Ustrcmp(lcp->password, password) != 0))
520 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
521 (lcp->bound)? "re-" : "", user, password);
524 #if defined(LDAP_OPT_X_TLS) && !defined(LDAP_LIB_SOLARIS)
525 /* The Oracle LDAP libraries (LDAP_LIB_TYPE=SOLARIS) don't support this.
526 * Note: moreover, they appear to now define LDAP_OPT_X_TLS and still not
527 * export an ldap_start_tls_s symbol.
529 if ( (rc = ldap_start_tls_s(lcp->ld, NULL, NULL)) != LDAP_SUCCESS)
531 *errmsg = string_sprintf("failed to initiate TLS processing on an "
532 "LDAP session to server %s%s - ldap_start_tls_s() returned %d:"
533 " %s", host, porttext, rc, ldap_err2string(rc));
538 debug_printf("TLS initiation not supported with this Exim and your LDAP library.\n");
541 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
544 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
545 "%s%s - ldap_bind() returned -1", host, porttext);
549 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
551 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
552 "%s%s - LDAP error: %s", host, porttext,
553 rc == -1 ? "result retrieval failed" : "timeout" );
558 rc = ldap_result2error( lcp->ld, result, 0 );
560 /* Invalid credentials when just checking credentials returns FAIL. This
561 stops any further servers being tried. */
563 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
566 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
568 goto RETURN_ERROR_NOMSG;
571 /* Otherwise we have a problem that doesn't stop further servers from being
574 if (rc != LDAP_SUCCESS)
576 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
577 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
581 /* Successful bind */
584 lcp->user = (user == NULL)? NULL : string_copy(user);
585 lcp->password = (password == NULL)? NULL : string_copy(password);
587 ldap_msgfree(result);
591 /* If we are just checking credentials, return OK. */
593 if (search_type == SEARCH_LDAP_AUTH)
595 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
599 /* Before doing the search, set the time and size limits (if given). Here again
600 the different implementations of LDAP have chosen to do things differently. */
602 #if defined(LDAP_OPT_SIZELIMIT)
603 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
604 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
606 lcp->ld->ld_sizelimit = sizelimit;
607 lcp->ld->ld_timelimit = timelimit;
610 /* Similarly for dereferencing aliases. Don't know if this is possible on
611 an LDAP library without LDAP_OPT_DEREF. */
613 #if defined(LDAP_OPT_DEREF)
614 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
617 /* Similarly for the referral setting; should the library follow referrals that
618 the LDAP server returns? The conditional is just in case someone uses a library
621 #if defined(LDAP_OPT_REFERRALS)
622 ldap_set_option(lcp->ld, LDAP_OPT_REFERRALS, referrals);
625 /* Start the search on the server. */
627 DEBUG(D_lookup) debug_printf("Start search\n");
629 msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
634 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
636 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
637 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
638 ldap_err2string(err));
641 *errmsg = string_sprintf("ldap_search failed");
647 /* Loop to pick up results as they come in, setting a timeout if one was
650 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
651 LDAP_RES_SEARCH_ENTRY)
655 DEBUG(D_lookup) debug_printf("ldap_result loop\n");
657 for(e = ldap_first_entry(lcp->ld, result);
659 e = ldap_next_entry(lcp->ld, e))
662 BOOL insert_space = FALSE;
664 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
666 rescount++; /* Count results */
668 /* Results for multiple entries values are separated by newlines. */
670 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
672 /* Get the DN from the last result. */
674 new_dn = US ldap_get_dn(lcp->ld, e);
679 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
681 #else /* OPENLDAP 1, UMich, Solaris */
689 /* If the data we want is actually the DN rather than any attribute values,
690 (an "ldapdn" search) add it to the data string. If there are multiple
691 entries, the DNs will be concatenated, but we test for this case below, as
692 for SEARCH_LDAP_SINGLE, and give an error. */
694 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
695 { /* condition, because of the else */
696 if (new_dn != NULL) /* below, that's for the first only */
698 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
700 attribute_found = TRUE;
704 /* Otherwise, loop through the entry, grabbing attribute values. If there's
705 only one attribute being retrieved, no attribute name is given, and the
706 result is not quoted. Multiple values are separated by (comma, space).
707 If more than one attribute is being retrieved, the data is given as a
708 sequence of name=value pairs, with the value always in quotes. If there are
709 multiple values, they are given within the quotes, comma separated. */
711 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
713 attr = US ldap_next_attribute(lcp->ld, e, ber))
717 /* Get array of values for this attribute. */
719 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
725 data = string_cat(data, &size, &ptr, US" ", 1);
728 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
729 data = string_cat(data, &size, &ptr, US"=\"", 2);
732 while (*values != NULL)
734 uschar *value = *values;
735 int len = Ustrlen(value);
737 DEBUG(D_lookup) debug_printf("LDAP attr loop %s:%s\n", attr, value);
739 if (values != firstval)
740 data = string_cat(data, &size, &ptr, US",", 1);
742 /* For multiple attributes, the data is in quotes. We must escape
743 internal quotes, backslashes, newlines, and must double commas. */
748 for (j = 0; j < len; j++)
750 if (value[j] == '\n')
751 data = string_cat(data, &size, &ptr, US"\\n", 2);
752 else if (value[j] == ',')
753 data = string_cat(data, &size, &ptr, US",,", 2);
756 if (value[j] == '\"' || value[j] == '\\')
757 data = string_cat(data, &size, &ptr, US"\\", 1);
758 data = string_cat(data, &size, &ptr, value+j, 1);
763 /* For single attributes, just double commas */
768 for (j = 0; j < len; j++)
771 data = string_cat(data, &size, &ptr, US",,", 2);
773 data = string_cat(data, &size, &ptr, value+j, 1);
778 /* Move on to the next value */
781 attribute_found = TRUE;
784 /* Closing quote at the end of the data for a named attribute. */
787 data = string_cat(data, &size, &ptr, US"\"", 1);
789 /* Free the values */
791 ldap_value_free(CSS firstval);
795 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
797 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
798 to be freed. UMich LDAP stores them in static storage and does not require
803 } /* End "for" loop for extracting attributes from an entry */
804 } /* End "for" loop for extracting entries from a result */
806 /* Free the result */
808 ldap_msgfree(result);
810 } /* End "while" loop for multiple results */
812 /* Terminate the dynamic string that we have built and reclaim unused store */
817 store_reset(data + ptr + 1);
820 /* Copy the last dn into eldap_dn */
824 eldap_dn = string_copy(dn);
825 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
827 #else /* OPENLDAP 1, UMich, Solaris */
832 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
836 *errmsg = US"ldap_result timed out";
840 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
841 provide you with a message". Other error states seem to exist where
842 ldap_result() didn't give us any message from the server at all, leaving result
843 set to NULL. Apparently, "the error parameters of the LDAP session handle will
844 be set accordingly". That's the best we can do to retrieve an error status; we
845 can't use functions like ldap_result2error because they parse a message from
846 the server, which we didn't get.
848 Annoyingly, the different implementations of LDAP have gone for different
849 methods of handling error codes and generating error messages. */
851 if (rc == -1 || result == NULL)
854 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
856 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
857 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
858 *errmsg = string_sprintf("ldap_result failed: %d, %s",
859 err, ldap_err2string(err));
861 #elif defined LDAP_LIB_NETSCAPE
862 /* Dubious (surely 'matched' is spurious here?) */
863 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
864 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
866 #else /* UMich LDAP aka OpenLDAP 1.x */
867 *errmsg = string_sprintf("ldap_result failed: %d, %s",
868 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
874 /* A return code that isn't -1 doesn't necessarily mean there were no problems
875 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
876 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
877 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
878 we don't provide that functionality when we can't. :-) */
880 if (rc != LDAP_RES_SEARCH_RESULT
881 #ifdef LDAP_RES_SEARCH_REFERENCE
882 && rc != LDAP_RES_SEARCH_REFERENCE
886 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
890 /* We have a result message from the server. This doesn't yet mean all is well.
891 We need to parse the message to find out exactly what's happened. */
893 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
895 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
896 CSS &error2, NULL, NULL, 0);
897 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
898 if (ldap_parse_rc < 0 &&
899 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
900 #ifdef LDAP_RES_SEARCH_REFERENCE
901 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
905 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
908 error1 = US ldap_err2string(rc);
910 #elif defined LDAP_LIB_NETSCAPE
911 /* Dubious (it doesn't reference 'result' at all!) */
912 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
914 #else /* UMich LDAP aka OpenLDAP 1.x */
915 rc = ldap_result2error(lcp->ld, result, 0);
916 error1 = ldap_err2string(rc);
917 error2 = lcp->ld->ld_error;
918 matched = lcp->ld->ld_matched;
921 /* Process the status as follows:
923 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
924 truncated result list.
926 (2) If we get LDAP_RES_SEARCH_REFERENCE, also just carry on. This was a
927 submitted patch that is reported to "do the right thing" with Solaris
928 LDAP libraries. (The problem it addresses apparently does not occur with
931 (3) The range of errors defined by LDAP_NAME_ERROR generally mean "that
932 object does not, or cannot, exist in the database". For those cases we
935 (4) All other non-successes here are treated as some kind of problem with
936 the lookup, so return DEFER (which is the default in error_yield).
939 DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
940 rc, ldap_err2string(rc));
942 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED
943 #ifdef LDAP_RES_SEARCH_REFERENCE
944 && rc != LDAP_RES_SEARCH_REFERENCE
948 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
950 (error1 != NULL)? error1 : US"",
951 (error2 != NULL && error2[0] != 0)? US"/" : US"",
952 (error2 != NULL)? error2 : US"",
953 (matched != NULL && matched[0] != 0)? US"/" : US"",
954 (matched != NULL)? matched : US"");
956 #if defined LDAP_NAME_ERROR
957 if (LDAP_NAME_ERROR(rc))
958 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
961 if (rc == LDAP_NO_SUCH_OBJECT)
965 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
971 /* The search succeeded. Check if we have too many results */
973 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
975 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
976 "(filter not specific enough?)", rescount);
977 goto RETURN_ERROR_BREAK;
980 /* Check if we have too few (zero) entries */
984 *errmsg = string_sprintf("LDAP search: no results");
986 goto RETURN_ERROR_BREAK;
989 /* If an entry was found, but it had no attributes, we behave as if no entries
990 were found, that is, the lookup failed. */
992 if (!attribute_found)
994 *errmsg = US"LDAP search: found no attributes";
999 /* Otherwise, it's all worked */
1001 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
1005 if (result != NULL) ldap_msgfree(result);
1006 ldap_free_urldesc(ludp);
1012 *defer_break = TRUE;
1015 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1018 if (result != NULL) ldap_msgfree(result);
1019 if (ludp != NULL) ldap_free_urldesc(ludp);
1021 #if defined LDAP_LIB_OPENLDAP2
1022 if (error2 != NULL) ldap_memfree(error2);
1023 if (matched != NULL) ldap_memfree(matched);
1031 /*************************************************
1032 * Internal search control function *
1033 *************************************************/
1035 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
1036 and eldapm_find() with a difference in the "search_type" argument. It controls
1037 calls to perform_ldap_search() which actually does the work. We call that
1038 repeatedly for certain types of defer in the case when the URL contains no host
1039 name and eldap_default_servers is set to a list of servers to try. This gives
1040 more control than just passing over a list of hosts to ldap_open() because it
1041 handles other kinds of defer as well as just a failure to open. Note that the
1042 URL is defined to contain either zero or one "hostport" only.
1044 Parameter data in addition to the URL can be passed as preceding text in the
1045 string, as items of the form XXX=yyy. The URL itself can be detected because it
1046 must begin "ldapx://", where x is empty, s, or i.
1049 ldap_url the URL to be looked up, optionally preceded by other parameter
1051 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
1052 SEARCH_LDAP_SINGLE allows values from one entry only
1053 SEARCH_LDAP_DN gets the DN from one entry
1054 res set to point at the result
1055 errmsg set to point a message if result is not OK
1057 Returns: OK or FAIL or DEFER
1061 control_ldap_search(uschar *ldap_url, int search_type, uschar **res,
1064 BOOL defer_break = FALSE;
1065 int timelimit = LDAP_NO_LIMIT;
1066 int sizelimit = LDAP_NO_LIMIT;
1069 int dereference = LDAP_DEREF_NEVER;
1070 void* referrals = LDAP_OPT_ON;
1071 uschar *url = ldap_url;
1073 uschar *user = NULL;
1074 uschar *password = NULL;
1075 uschar *server, *list;
1078 while (isspace(*url)) url++;
1080 /* Until the string begins "ldap", search for the other parameter settings that
1081 are recognized. They are of the form NAME=VALUE, with the value being
1082 optionally double-quoted. There must still be a space after it, however. No
1083 NAME has the value "ldap". */
1085 while (strncmpic(url, US"ldap", 4) != 0)
1088 while (*url != 0 && *url != '=') url++;
1093 namelen = ++url - name;
1094 value = string_dequote(&url);
1097 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1098 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1099 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1100 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1101 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1102 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1104 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1106 #ifdef LDAP_OPT_DEREF
1107 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1109 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1110 else if (strcmpic(value, US"searching") == 0)
1111 dereference = LDAP_DEREF_SEARCHING;
1112 else if (strcmpic(value, US"finding") == 0)
1113 dereference = LDAP_DEREF_FINDING;
1114 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1117 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1119 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1120 "library - cannot use \"dereference\"");
1121 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1126 #ifdef LDAP_OPT_REFERRALS
1127 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1129 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1130 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1133 *errmsg = string_sprintf("LDAP option REFERRALS is not \"follow\" "
1135 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1140 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1142 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1143 "library - cannot use \"referrals\"");
1144 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1152 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1154 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1157 while (isspace(*url)) url++;
1161 *errmsg = US"malformed parameter setting precedes LDAP URL";
1162 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1166 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1167 but it seems that not all behave like this. The DN for the user is often the
1168 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1169 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1170 far too complicated. */
1176 for (s = user; *s != 0; s++)
1179 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1184 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1185 ((d >= 'a')? (10 + d - 'a') : d - '0');
1194 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1195 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1196 tcplimit, dereference, (referrals == LDAP_OPT_ON)? "on" : "off");
1198 /* If the request is just to check authentication, some credentials must
1199 be given. The password must not be empty because LDAP binds with an empty
1200 password are considered anonymous, and will succeed on most installations. */
1202 if (search_type == SEARCH_LDAP_AUTH)
1204 if (user == NULL || password == NULL)
1206 *errmsg = US"ldapauth lookups must specify the username and password";
1209 if (password[0] == 0)
1211 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1216 /* Check for valid ldap url starters */
1219 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1220 if (Ustrncmp(p, "://", 3) != 0)
1222 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1223 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1224 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1228 /* No default servers, or URL contains a server name: just one attempt */
1230 if (eldap_default_servers == NULL || p[3] != '/')
1232 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1233 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1237 /* Loop through the default servers until OK or FAIL */
1239 list = eldap_default_servers;
1240 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1244 uschar *colon = Ustrchr(server, ':');
1248 port = Uatoi(colon+1);
1250 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1251 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1253 if (rc != DEFER || defer_break) return rc;
1261 /*************************************************
1262 * Find entry point *
1263 *************************************************/
1265 /* See local README for interface description. The different kinds of search
1266 are handled by a common function, with a flag to differentiate between them.
1267 The handle and filename arguments are not used. */
1270 eldap_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1271 uschar **result, uschar **errmsg, BOOL *do_cache)
1273 /* Keep picky compilers happy */
1274 do_cache = do_cache;
1275 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1279 eldapm_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1280 uschar **result, uschar **errmsg, BOOL *do_cache)
1282 /* Keep picky compilers happy */
1283 do_cache = do_cache;
1284 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1288 eldapdn_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1289 uschar **result, uschar **errmsg, BOOL *do_cache)
1291 /* Keep picky compilers happy */
1292 do_cache = do_cache;
1293 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1297 eldapauth_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1298 uschar **result, uschar **errmsg, BOOL *do_cache)
1300 /* Keep picky compilers happy */
1301 do_cache = do_cache;
1302 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1307 /*************************************************
1308 * Open entry point *
1309 *************************************************/
1311 /* See local README for interface description. */
1314 eldap_open(uschar *filename, uschar **errmsg)
1316 return (void *)(1); /* Just return something non-null */
1321 /*************************************************
1322 * Tidy entry point *
1323 *************************************************/
1325 /* See local README for interface description.
1326 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1331 LDAP_CONNECTION *lcp = NULL;
1334 while ((lcp = ldap_connections) != NULL)
1336 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1338 ldap_unbind(lcp->ld);
1339 ldap_connections = lcp->next;
1345 /*************************************************
1346 * Quote entry point *
1347 *************************************************/
1349 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1350 quoting have to be done: LDAP quoting, and URL quoting. The current
1351 specification is the result of a suggestion by Brian Candler. It recognizes
1354 (1) For text that appears in a search filter, the following escapes are
1355 required (see RFC 2254):
1363 Then the entire filter text must be URL-escaped. This kind of quoting is
1364 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1365 in the input string, because that's a terminator.
1367 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1371 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1372 must be escaped, as must a leading #. Then the string must be URL-quoted.
1373 This type of quoting is implemented by ${quote_ldap_dn:....}.
1375 For URL quoting, the only characters that need not be quoted are the
1380 All the others must be hexified and preceded by %. This includes the
1381 backslashes used for LDAP quoting.
1383 For a DN that is given in the USER parameter for authentication, we need the
1384 same initial quoting as (2) but in this case, the result must NOT be
1385 URL-escaped, because it isn't a URL. The way this is handled is by
1386 de-URL-quoting the text when processing the USER parameter in
1387 control_ldap_search() above. That means that the same quote operator can be
1388 used. This has the additional advantage that spaces in the DN won't cause
1389 parsing problems. For example:
1391 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1393 should be safe if there are spaces in $1.
1397 s the string to be quoted
1398 opt additional option text or NULL if none
1399 only "dn" is recognized
1401 Returns: the processed string or NULL for a bad option
1406 /* The characters in this string, together with alphanumerics, never need
1407 quoting in any way. */
1409 #define ALWAYS_LITERAL "!$'-._"
1411 /* The special characters in this string do not need to be URL-quoted. The set
1412 is a bit larger than the general literals. */
1414 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1416 /* The following macros define the characters that are quoted by quote_ldap and
1417 quote_ldap_dn, respectively. */
1419 #define LDAP_QUOTE "*()\\"
1420 #define LDAP_DN_QUOTE ",+\"\\<>;"
1425 eldap_quote(uschar *s, uschar *opt)
1434 /* Test for a DN quotation. */
1438 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1442 /* Compute how much extra store we need for the string. This doesn't have to be
1443 exact as long as it isn't an underestimate. The worst case is the addition of 5
1444 extra bytes for a single character. This occurs for certain characters in DNs,
1445 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1446 possibly escaped character. The really fast way would be just to test for
1447 non-alphanumerics, but it is probably better to spot a few others that are
1448 never escaped, because if there are no specials at all, we can avoid copying
1451 while ((c = *t++) != 0)
1454 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1456 if (count == 0) return s;
1458 /* Get sufficient store to hold the quoted string */
1460 t = quoted = store_get(len + count + 1);
1462 /* Handle plain quote_ldap */
1466 while ((c = *s++) != 0)
1470 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1472 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1476 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1478 sprintf(CS t, "%%%02X", c);
1483 *t++ = c; /* unquoted character */
1487 /* Handle quote_ldap_dn */
1491 uschar *ss = s + len;
1493 /* Find the last char before any trailing spaces */
1495 while (ss > s && ss[-1] == ' ') ss--;
1497 /* Quote leading spaces and sharps */
1501 if (*s != ' ' && *s != '#') break;
1502 sprintf(CS t, "%%5C%%%02X", *s);
1506 /* Handle the rest of the string, up to the trailing spaces */
1513 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1515 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1516 t += 3; /* fall through to check URL */
1518 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1520 sprintf(CS t, "%%%02X", c);
1525 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1528 /* Handle the trailing spaces */
1532 Ustrncpy(t, "%5C%20", 6);
1537 /* Terminate the new string and return */
1545 /*************************************************
1546 * Version reporting entry point *
1547 *************************************************/
1549 /* See local README for interface description. */
1551 #include "../version.h"
1554 ldap_version_report(FILE *f)
1557 fprintf(f, "Library version: LDAP: Exim version %s\n", EXIM_VERSION_STR);
1562 static lookup_info ldap_lookup_info = {
1563 US"ldap", /* lookup name */
1564 lookup_querystyle, /* query-style lookup */
1565 eldap_open, /* open function */
1566 NULL, /* check function */
1567 eldap_find, /* find function */
1568 NULL, /* no close function */
1569 eldap_tidy, /* tidy function */
1570 eldap_quote, /* quoting function */
1571 ldap_version_report /* version reporting */
1574 static lookup_info ldapdn_lookup_info = {
1575 US"ldapdn", /* lookup name */
1576 lookup_querystyle, /* query-style lookup */
1577 eldap_open, /* sic */ /* open function */
1578 NULL, /* check function */
1579 eldapdn_find, /* find function */
1580 NULL, /* no close function */
1581 eldap_tidy, /* sic */ /* tidy function */
1582 eldap_quote, /* sic */ /* quoting function */
1583 NULL /* no version reporting (redundant) */
1586 static lookup_info ldapm_lookup_info = {
1587 US"ldapm", /* lookup name */
1588 lookup_querystyle, /* query-style lookup */
1589 eldap_open, /* sic */ /* open function */
1590 NULL, /* check function */
1591 eldapm_find, /* find function */
1592 NULL, /* no close function */
1593 eldap_tidy, /* sic */ /* tidy function */
1594 eldap_quote, /* sic */ /* quoting function */
1595 NULL /* no version reporting (redundant) */
1599 #define ldap_lookup_module_info _lookup_module_info
1602 static lookup_info *_lookup_list[] = { &ldap_lookup_info, &ldapdn_lookup_info, &ldapm_lookup_info };
1603 lookup_module_info ldap_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
1605 /* End of lookups/ldap.c */