Bug 1453: Add SERVERS ldap server list override
[exim.git] / src / src / lookups / ldap.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2014 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
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. */
12
13
14 #include "../exim.h"
15 #include "lf_functions.h"
16
17
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
21 ldap.h. */
22
23 #define LDAP_DEPRECATED 1
24
25 #include <lber.h>
26 #include <ldap.h>
27
28
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:
34
35 LDAP_LIB_NETSCAPE
36 LDAP_LIB_SOLARIS with synonym LDAP_LIB_SOLARIS7
37 LDAP_LIB_OPENLDAP2
38
39 These others may be defined, but are in fact the default, so are not tested:
40
41 LDAP_LIB_UMICHIGAN
42 LDAP_LIB_OPENLDAP1
43 */
44
45 #if defined(LDAP_LIB_SOLARIS7) && ! defined(LDAP_LIB_SOLARIS)
46 #define LDAP_LIB_SOLARIS
47 #endif
48
49
50 /* Just in case LDAP_NO_LIMIT is not defined by some of these libraries. */
51
52 #ifndef LDAP_NO_LIMIT
53 #define LDAP_NO_LIMIT 0
54 #endif
55
56
57 /* Just in case LDAP_DEREF_NEVER is not defined */
58
59 #ifndef LDAP_DEREF_NEVER
60 #define LDAP_DEREF_NEVER 0
61 #endif
62
63
64 /* Four types of LDAP search are implemented */
65
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 */
70
71 /* In all 4 cases, the DN is left in $ldap_dn (which post-dates the
72 SEARCH_LDAP_DN lookup). */
73
74
75 /* Structure and anchor for caching connections. */
76
77 typedef struct ldap_connection {
78 struct ldap_connection *next;
79 uschar *host;
80 uschar *user;
81 uschar *password;
82 BOOL bound;
83 int port;
84 BOOL is_start_tls_called;
85 LDAP *ld;
86 } LDAP_CONNECTION;
87
88 static LDAP_CONNECTION *ldap_connections = NULL;
89
90
91
92 /*************************************************
93 * Internal search function *
94 *************************************************/
95
96 /* This is the function that actually does the work. It is called (indirectly
97 via control_ldap_search) from eldap_find(), eldapauth_find(), eldapdn_find(),
98 and eldapm_find(), with a difference in the "search_type" argument.
99
100 The case of eldapauth_find() is special in that all it does is do
101 authentication, returning OK or FAIL as appropriate. This isn't used as a
102 lookup. Instead, it is called from expand.c as an expansion condition test.
103
104 The DN from a successful lookup is placed in $ldap_dn. This feature postdates
105 the provision of the SEARCH_LDAP_DN facility for returning just the DN as the
106 data.
107
108 Arguments:
109 ldap_url the URL to be looked up
110 server server host name, when URL contains none
111 s_port server port, used when URL contains no name
112 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
113 SEARCH_LDAP_SINGLE allows values from one entry only
114 SEARCH_LDAP_DN gets the DN from one entry
115 res set to point at the result (not used for ldapauth)
116 errmsg set to point a message if result is not OK
117 defer_break set TRUE if no more servers to be tried after a DEFER
118 user user name for authentication, or NULL
119 password password for authentication, or NULL
120 sizelimit max number of entries returned, or 0 for no limit
121 timelimit max time to wait, or 0 for no limit
122 tcplimit max time for network activity, e.g. connect, or 0 for OS default
123 deference the dereference option, which is one of
124 LDAP_DEREF_{NEVER,SEARCHING,FINDING,ALWAYS}
125 referrals the referral option, which is LDAP_OPT_ON or LDAP_OPT_OFF
126
127 Returns: OK or FAIL or DEFER
128 FAIL is given only if a lookup was performed successfully, but
129 returned no data.
130 */
131
132 static int
133 perform_ldap_search(uschar *ldap_url, uschar *server, int s_port, int search_type,
134 uschar **res, uschar **errmsg, BOOL *defer_break, uschar *user, uschar *password,
135 int sizelimit, int timelimit, int tcplimit, int dereference, void *referrals)
136 {
137 LDAPURLDesc *ludp = NULL;
138 LDAPMessage *result = NULL;
139 BerElement *ber;
140 LDAP_CONNECTION *lcp;
141
142 struct timeval timeout;
143 struct timeval *timeoutptr = NULL;
144
145 uschar *attr;
146 uschar **attrp;
147 uschar *data = NULL;
148 uschar *dn = NULL;
149 uschar *host;
150 uschar **values;
151 uschar **firstval;
152 uschar porttext[16];
153
154 uschar *error1 = NULL; /* string representation of errcode (static) */
155 uschar *error2 = NULL; /* error message from the server */
156 uschar *matched = NULL; /* partially matched DN */
157
158 int attr_count = 0;
159 int error_yield = DEFER;
160 int msgid;
161 int rc, ldap_rc, ldap_parse_rc;
162 int port;
163 int ptr = 0;
164 int rescount = 0;
165 int size = 0;
166 BOOL attribute_found = FALSE;
167 BOOL ldapi = FALSE;
168
169 DEBUG(D_lookup)
170 debug_printf("perform_ldap_search: ldap%s URL = \"%s\" server=%s port=%d "
171 "sizelimit=%d timelimit=%d tcplimit=%d\n",
172 (search_type == SEARCH_LDAP_MULTIPLE)? "m" :
173 (search_type == SEARCH_LDAP_DN)? "dn" :
174 (search_type == SEARCH_LDAP_AUTH)? "auth" : "",
175 ldap_url, server, s_port, sizelimit, timelimit, tcplimit);
176
177 /* Check if LDAP thinks the URL is a valid LDAP URL. We assume that if the LDAP
178 library that is in use doesn't recognize, say, "ldapi", it will barf here. */
179
180 if (!ldap_is_ldap_url(CS ldap_url))
181 {
182 *errmsg = string_sprintf("ldap_is_ldap_url: not an LDAP url \"%s\"\n",
183 ldap_url);
184 goto RETURN_ERROR_BREAK;
185 }
186
187 /* Parse the URL */
188
189 if ((rc = ldap_url_parse(CS ldap_url, &ludp)) != 0)
190 {
191 *errmsg = string_sprintf("ldap_url_parse: (error %d) parsing \"%s\"\n", rc,
192 ldap_url);
193 goto RETURN_ERROR_BREAK;
194 }
195
196 /* If the host name is empty, take it from the separate argument, if one is
197 given. OpenLDAP 2.0.6 sets an unset hostname to "" rather than empty, but
198 expects NULL later in ldap_init() to mean "default", annoyingly. In OpenLDAP
199 2.0.11 this has changed (it uses NULL). */
200
201 if ((ludp->lud_host == NULL || ludp->lud_host[0] == 0) && server != NULL)
202 {
203 host = server;
204 port = s_port;
205 }
206 else
207 {
208 host = US ludp->lud_host;
209 if (host != NULL && host[0] == 0) host = NULL;
210 port = ludp->lud_port;
211 }
212
213 DEBUG(D_lookup) debug_printf("after ldap_url_parse: host=%s port=%d\n",
214 host, port);
215
216 if (port == 0) port = LDAP_PORT; /* Default if none given */
217 sprintf(CS porttext, ":%d", port); /* For messages */
218
219 /* If the "host name" is actually a path, we are going to connect using a Unix
220 socket, regardless of whether "ldapi" was actually specified or not. This means
221 that a Unix socket can be declared in eldap_default_servers, and "traditional"
222 LDAP queries using just "ldap" can be used ("ldaps" is similarly overridden).
223 The path may start with "/" or it may already be escaped as "%2F" if it was
224 actually declared that way in eldap_default_servers. (I did it that way the
225 first time.) If the host name is not a path, the use of "ldapi" causes an
226 error, except in the default case. (But lud_scheme doesn't seem to exist in
227 older libraries.) */
228
229 if (host != NULL)
230 {
231 if ((host[0] == '/' || Ustrncmp(host, "%2F", 3) == 0))
232 {
233 ldapi = TRUE;
234 porttext[0] = 0; /* Remove port from messages */
235 }
236
237 #if defined LDAP_LIB_OPENLDAP2
238 else if (strncmp(ludp->lud_scheme, "ldapi", 5) == 0)
239 {
240 *errmsg = string_sprintf("ldapi requires an absolute path (\"%s\" given)",
241 host);
242 goto RETURN_ERROR;
243 }
244 #endif
245 }
246
247 /* Count the attributes; we need this later to tell us how to format results */
248
249 for (attrp = USS ludp->lud_attrs; attrp != NULL && *attrp != NULL; attrp++)
250 attr_count++;
251
252 /* See if we can find a cached connection to this host. The port is not
253 relevant for ldapi. The host name pointer is set to NULL if no host was given
254 (implying the library default), rather than to the empty string. Note that in
255 this case, there is no difference between ldap and ldapi. */
256
257 for (lcp = ldap_connections; lcp != NULL; lcp = lcp->next)
258 {
259 if ((host == NULL) != (lcp->host == NULL) ||
260 (host != NULL && strcmpic(lcp->host, host) != 0))
261 continue;
262 if (ldapi || port == lcp->port) break;
263 }
264
265 /* Use this network timeout in any requests. */
266
267 if (tcplimit > 0)
268 {
269 timeout.tv_sec = tcplimit;
270 timeout.tv_usec = 0;
271 timeoutptr = &timeout;
272 }
273
274 /* If no cached connection found, we must open a connection to the server. If
275 the server name is actually an absolute path, we set ldapi=TRUE above. This
276 requests connection via a Unix socket. However, as far as I know, only OpenLDAP
277 supports the use of sockets, and the use of ldap_initialize(). */
278
279 if (lcp == NULL)
280 {
281 LDAP *ld;
282
283 #ifdef LDAP_OPT_X_TLS_NEWCTX
284 int am_server = 0;
285 LDAP *ldsetctx;
286 #else
287 LDAP *ldsetctx = NULL;
288 #endif
289
290
291 /* --------------------------- OpenLDAP ------------------------ */
292
293 /* There seems to be a preference under OpenLDAP for ldap_initialize()
294 instead of ldap_init(), though I have as yet been unable to find
295 documentation that says this. (OpenLDAP documentation is sparse to
296 non-existent). So we handle OpenLDAP differently here. Also, support for
297 ldapi seems to be OpenLDAP-only at present. */
298
299 #ifdef LDAP_LIB_OPENLDAP2
300
301 /* We now need an empty string for the default host. Get some store in which
302 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
303 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
304 than the host name + "ldaps:///" plus : and a port number, say 20 + the
305 length of the host name. What we get should accommodate both, easily. */
306
307 uschar *shost = (host == NULL)? US"" : host;
308 uschar *init_url = store_get(20 + 3 * Ustrlen(shost));
309 uschar *init_ptr;
310
311 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
312 contain the path name, with slashes escaped as %2F. */
313
314 if (ldapi)
315 {
316 int ch;
317 init_ptr = init_url + 8;
318 Ustrcpy(init_url, "ldapi://");
319 while ((ch = *shost++) != 0)
320 {
321 if (ch == '/')
322 {
323 Ustrncpy(init_ptr, "%2F", 3);
324 init_ptr += 3;
325 }
326 else *init_ptr++ = ch;
327 }
328 *init_ptr = 0;
329 }
330
331 /* This is not an ldapi call. Just build a URI with the protocol type, host
332 name, and port. */
333
334 else
335 {
336 init_ptr = Ustrchr(ldap_url, '/');
337 Ustrncpy(init_url, ldap_url, init_ptr - ldap_url);
338 init_ptr = init_url + (init_ptr - ldap_url);
339 sprintf(CS init_ptr, "//%s:%d/", shost, port);
340 }
341
342 /* Call ldap_initialize() and check the result */
343
344 DEBUG(D_lookup) debug_printf("ldap_initialize with URL %s\n", init_url);
345 rc = ldap_initialize(&ld, CS init_url);
346 if (rc != LDAP_SUCCESS)
347 {
348 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
349 rc, init_url);
350 goto RETURN_ERROR;
351 }
352 store_reset(init_url); /* Might as well save memory when we can */
353
354
355 /* ------------------------- Not OpenLDAP ---------------------- */
356
357 /* For libraries other than OpenLDAP, use ldap_init(). */
358
359 #else /* LDAP_LIB_OPENLDAP2 */
360 ld = ldap_init(CS host, port);
361 #endif /* LDAP_LIB_OPENLDAP2 */
362
363 /* -------------------------------------------------------------- */
364
365
366 /* Handle failure to initialize */
367
368 if (ld == NULL)
369 {
370 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
371 host, porttext, strerror(errno));
372 goto RETURN_ERROR;
373 }
374
375 #ifdef LDAP_OPT_X_TLS_NEWCTX
376 ldsetctx = ld;
377 #endif
378
379 /* Set the TCP connect time limit if available. This is something that is
380 in Netscape SDK v4.1; I don't know about other libraries. */
381
382 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
383 if (tcplimit > 0)
384 {
385 int timeout1000 = tcplimit*1000;
386 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
387 }
388 else
389 {
390 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
391 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&notimeout);
392 }
393 #endif
394
395 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
396
397 #ifdef LDAP_OPT_NETWORK_TIMEOUT
398 if (tcplimit > 0)
399 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
400 #endif
401
402 /* I could not get TLS to work until I set the version to 3. That version
403 seems to be the default nowadays. The RFC is dated 1997, so I would hope
404 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
405 been set, go for v3 if we can. */
406
407 if (eldap_version < 0)
408 {
409 #ifdef LDAP_VERSION3
410 eldap_version = LDAP_VERSION3;
411 #else
412 eldap_version = 2;
413 #endif
414 }
415
416 #ifdef LDAP_OPT_PROTOCOL_VERSION
417 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
418 #endif
419
420 DEBUG(D_lookup) debug_printf("initialized for LDAP (v%d) server %s%s\n",
421 eldap_version, host, porttext);
422
423 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
424 for "ldaps" and soft otherwise. */
425
426 #ifdef LDAP_OPT_X_TLS
427 if (!ldapi)
428 {
429 int tls_option;
430 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
431 if (eldap_require_cert != NULL)
432 {
433 tls_option = LDAP_OPT_X_TLS_NEVER;
434 if (Ustrcmp(eldap_require_cert, "hard") == 0)
435 {
436 tls_option = LDAP_OPT_X_TLS_HARD;
437 }
438 else if (Ustrcmp(eldap_require_cert, "demand") == 0)
439 {
440 tls_option = LDAP_OPT_X_TLS_DEMAND;
441 }
442 else if (Ustrcmp(eldap_require_cert, "allow") == 0)
443 {
444 tls_option = LDAP_OPT_X_TLS_ALLOW;
445 }
446 else if (Ustrcmp(eldap_require_cert, "try") == 0)
447 {
448 tls_option = LDAP_OPT_X_TLS_TRY;
449 }
450 DEBUG(D_lookup)
451 debug_printf("Require certificate overrides LDAP_OPT_X_TLS option (%d)\n",
452 tls_option);
453 }
454 else
455 #endif /* LDAP_OPT_X_TLS_REQUIRE_CERT */
456 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
457 {
458 tls_option = LDAP_OPT_X_TLS_HARD;
459 DEBUG(D_lookup)
460 debug_printf("LDAP_OPT_X_TLS_HARD set due to ldaps:// URI\n");
461 }
462 else
463 {
464 tls_option = LDAP_OPT_X_TLS_TRY;
465 DEBUG(D_lookup)
466 debug_printf("LDAP_OPT_X_TLS_TRY set due to ldap:// URI\n");
467 }
468 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
469 }
470 #endif /* LDAP_OPT_X_TLS */
471
472 #ifdef LDAP_OPT_X_TLS_CACERTFILE
473 if (eldap_ca_cert_file != NULL)
474 {
475 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CACERTFILE, eldap_ca_cert_file);
476 }
477 #endif
478 #ifdef LDAP_OPT_X_TLS_CACERTDIR
479 if (eldap_ca_cert_dir != NULL)
480 {
481 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CACERTDIR, eldap_ca_cert_dir);
482 }
483 #endif
484 #ifdef LDAP_OPT_X_TLS_CERTFILE
485 if (eldap_cert_file != NULL)
486 {
487 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CERTFILE, eldap_cert_file);
488 }
489 #endif
490 #ifdef LDAP_OPT_X_TLS_KEYFILE
491 if (eldap_cert_key != NULL)
492 {
493 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_KEYFILE, eldap_cert_key);
494 }
495 #endif
496 #ifdef LDAP_OPT_X_TLS_CIPHER_SUITE
497 if (eldap_cipher_suite != NULL)
498 {
499 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CIPHER_SUITE, eldap_cipher_suite);
500 }
501 #endif
502 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
503 if (eldap_require_cert != NULL)
504 {
505 int cert_option = LDAP_OPT_X_TLS_NEVER;
506 if (Ustrcmp(eldap_require_cert, "hard") == 0)
507 {
508 cert_option = LDAP_OPT_X_TLS_HARD;
509 }
510 else if (Ustrcmp(eldap_require_cert, "demand") == 0)
511 {
512 cert_option = LDAP_OPT_X_TLS_DEMAND;
513 }
514 else if (Ustrcmp(eldap_require_cert, "allow") == 0)
515 {
516 cert_option = LDAP_OPT_X_TLS_ALLOW;
517 }
518 else if (Ustrcmp(eldap_require_cert, "try") == 0)
519 {
520 cert_option = LDAP_OPT_X_TLS_TRY;
521 }
522 /* This ldap handle is set at compile time based on client libs. Older
523 * versions want it to be global and newer versions can force a reload
524 * of the TLS context (to reload these settings we are changing from the
525 * default that loaded at instantiation). */
526 rc = ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_REQUIRE_CERT, &cert_option);
527 if (rc)
528 {
529 DEBUG(D_lookup)
530 debug_printf("Unable to set TLS require cert_option(%d) globally: %s\n",
531 cert_option, ldap_err2string(rc));
532 }
533 }
534 #endif
535 #ifdef LDAP_OPT_X_TLS_NEWCTX
536 rc = ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_NEWCTX, &am_server);
537 if (rc)
538 {
539 DEBUG(D_lookup)
540 debug_printf("Unable to reload TLS context %d: %s\n",
541 rc, ldap_err2string(rc));
542 }
543 #endif
544
545 /* Now add this connection to the chain of cached connections */
546
547 lcp = store_get(sizeof(LDAP_CONNECTION));
548 lcp->host = (host == NULL)? NULL : string_copy(host);
549 lcp->bound = FALSE;
550 lcp->user = NULL;
551 lcp->password = NULL;
552 lcp->port = port;
553 lcp->ld = ld;
554 lcp->next = ldap_connections;
555 lcp->is_start_tls_called = FALSE;
556 ldap_connections = lcp;
557 }
558
559 /* Found cached connection */
560
561 else
562 {
563 DEBUG(D_lookup)
564 debug_printf("re-using cached connection to LDAP server %s%s\n",
565 host, porttext);
566 }
567
568 /* Bind with the user/password supplied, or an anonymous bind if these values
569 are NULL, unless a cached connection is already bound with the same values. */
570
571 if (!lcp->bound ||
572 (lcp->user == NULL && user != NULL) ||
573 (lcp->user != NULL && user == NULL) ||
574 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
575 (lcp->password == NULL && password != NULL) ||
576 (lcp->password != NULL && password == NULL) ||
577 (lcp->password != NULL && password != NULL &&
578 Ustrcmp(lcp->password, password) != 0))
579 {
580 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
581 (lcp->bound)? "re-" : "", user, password);
582 if (eldap_start_tls && !lcp->is_start_tls_called)
583 {
584 #if defined(LDAP_OPT_X_TLS) && !defined(LDAP_LIB_SOLARIS)
585 /* The Oracle LDAP libraries (LDAP_LIB_TYPE=SOLARIS) don't support this.
586 * Note: moreover, they appear to now define LDAP_OPT_X_TLS and still not
587 * export an ldap_start_tls_s symbol.
588 */
589 if ( (rc = ldap_start_tls_s(lcp->ld, NULL, NULL)) != LDAP_SUCCESS)
590 {
591 *errmsg = string_sprintf("failed to initiate TLS processing on an "
592 "LDAP session to server %s%s - ldap_start_tls_s() returned %d:"
593 " %s", host, porttext, rc, ldap_err2string(rc));
594 goto RETURN_ERROR;
595 }
596 lcp->is_start_tls_called = TRUE;
597 #else
598 DEBUG(D_lookup)
599 debug_printf("TLS initiation not supported with this Exim and your LDAP library.\n");
600 #endif
601 }
602 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
603 == -1)
604 {
605 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
606 "%s%s - ldap_bind() returned -1", host, porttext);
607 goto RETURN_ERROR;
608 }
609
610 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
611 {
612 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
613 "%s%s - LDAP error: %s", host, porttext,
614 rc == -1 ? "result retrieval failed" : "timeout" );
615 result = NULL;
616 goto RETURN_ERROR;
617 }
618
619 rc = ldap_result2error( lcp->ld, result, 0 );
620
621 /* Invalid credentials when just checking credentials returns FAIL. This
622 stops any further servers being tried. */
623
624 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
625 {
626 DEBUG(D_lookup)
627 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
628 error_yield = FAIL;
629 goto RETURN_ERROR_NOMSG;
630 }
631
632 /* Otherwise we have a problem that doesn't stop further servers from being
633 tried. */
634
635 if (rc != LDAP_SUCCESS)
636 {
637 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
638 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
639 goto RETURN_ERROR;
640 }
641
642 /* Successful bind */
643
644 lcp->bound = TRUE;
645 lcp->user = (user == NULL)? NULL : string_copy(user);
646 lcp->password = (password == NULL)? NULL : string_copy(password);
647
648 ldap_msgfree(result);
649 result = NULL;
650 }
651
652 /* If we are just checking credentials, return OK. */
653
654 if (search_type == SEARCH_LDAP_AUTH)
655 {
656 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
657 goto RETURN_OK;
658 }
659
660 /* Before doing the search, set the time and size limits (if given). Here again
661 the different implementations of LDAP have chosen to do things differently. */
662
663 #if defined(LDAP_OPT_SIZELIMIT)
664 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
665 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
666 #else
667 lcp->ld->ld_sizelimit = sizelimit;
668 lcp->ld->ld_timelimit = timelimit;
669 #endif
670
671 /* Similarly for dereferencing aliases. Don't know if this is possible on
672 an LDAP library without LDAP_OPT_DEREF. */
673
674 #if defined(LDAP_OPT_DEREF)
675 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
676 #endif
677
678 /* Similarly for the referral setting; should the library follow referrals that
679 the LDAP server returns? The conditional is just in case someone uses a library
680 without it. */
681
682 #if defined(LDAP_OPT_REFERRALS)
683 ldap_set_option(lcp->ld, LDAP_OPT_REFERRALS, referrals);
684 #endif
685
686 /* Start the search on the server. */
687
688 DEBUG(D_lookup) debug_printf("Start search\n");
689
690 msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
691 ludp->lud_attrs, 0);
692
693 if (msgid == -1)
694 {
695 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
696 int err;
697 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
698 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
699 ldap_err2string(err));
700
701 #else
702 *errmsg = string_sprintf("ldap_search failed");
703 #endif
704
705 goto RETURN_ERROR;
706 }
707
708 /* Loop to pick up results as they come in, setting a timeout if one was
709 given. */
710
711 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
712 LDAP_RES_SEARCH_ENTRY)
713 {
714 LDAPMessage *e;
715
716 DEBUG(D_lookup) debug_printf("ldap_result loop\n");
717
718 for(e = ldap_first_entry(lcp->ld, result);
719 e != NULL;
720 e = ldap_next_entry(lcp->ld, e))
721 {
722 uschar *new_dn;
723 BOOL insert_space = FALSE;
724
725 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
726
727 rescount++; /* Count results */
728
729 /* Results for multiple entries values are separated by newlines. */
730
731 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
732
733 /* Get the DN from the last result. */
734
735 new_dn = US ldap_get_dn(lcp->ld, e);
736 if (new_dn != NULL)
737 {
738 if (dn != NULL)
739 {
740 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
741 ldap_memfree(dn);
742 #else /* OPENLDAP 1, UMich, Solaris */
743 free(dn);
744 #endif
745 }
746 /* Save for later */
747 dn = new_dn;
748 }
749
750 /* If the data we want is actually the DN rather than any attribute values,
751 (an "ldapdn" search) add it to the data string. If there are multiple
752 entries, the DNs will be concatenated, but we test for this case below, as
753 for SEARCH_LDAP_SINGLE, and give an error. */
754
755 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
756 { /* condition, because of the else */
757 if (new_dn != NULL) /* below, that's for the first only */
758 {
759 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
760 data[ptr] = 0;
761 attribute_found = TRUE;
762 }
763 }
764
765 /* Otherwise, loop through the entry, grabbing attribute values. If there's
766 only one attribute being retrieved, no attribute name is given, and the
767 result is not quoted. Multiple values are separated by (comma, space).
768 If more than one attribute is being retrieved, the data is given as a
769 sequence of name=value pairs, with the value always in quotes. If there are
770 multiple values, they are given within the quotes, comma separated. */
771
772 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
773 attr != NULL;
774 attr = US ldap_next_attribute(lcp->ld, e, ber))
775 {
776 if (attr[0] != 0)
777 {
778 /* Get array of values for this attribute. */
779
780 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
781 != NULL)
782 {
783 if (attr_count != 1)
784 {
785 if (insert_space)
786 data = string_cat(data, &size, &ptr, US" ", 1);
787 else
788 insert_space = TRUE;
789 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
790 data = string_cat(data, &size, &ptr, US"=\"", 2);
791 }
792
793 while (*values != NULL)
794 {
795 uschar *value = *values;
796 int len = Ustrlen(value);
797
798 DEBUG(D_lookup) debug_printf("LDAP attr loop %s:%s\n", attr, value);
799
800 if (values != firstval)
801 data = string_cat(data, &size, &ptr, US",", 1);
802
803 /* For multiple attributes, the data is in quotes. We must escape
804 internal quotes, backslashes, newlines, and must double commas. */
805
806 if (attr_count != 1)
807 {
808 int j;
809 for (j = 0; j < len; j++)
810 {
811 if (value[j] == '\n')
812 data = string_cat(data, &size, &ptr, US"\\n", 2);
813 else if (value[j] == ',')
814 data = string_cat(data, &size, &ptr, US",,", 2);
815 else
816 {
817 if (value[j] == '\"' || value[j] == '\\')
818 data = string_cat(data, &size, &ptr, US"\\", 1);
819 data = string_cat(data, &size, &ptr, value+j, 1);
820 }
821 }
822 }
823
824 /* For single attributes, just double commas */
825
826 else
827 {
828 int j;
829 for (j = 0; j < len; j++)
830 {
831 if (value[j] == ',')
832 data = string_cat(data, &size, &ptr, US",,", 2);
833 else
834 data = string_cat(data, &size, &ptr, value+j, 1);
835 }
836 }
837
838
839 /* Move on to the next value */
840
841 values++;
842 attribute_found = TRUE;
843 }
844
845 /* Closing quote at the end of the data for a named attribute. */
846
847 if (attr_count != 1)
848 data = string_cat(data, &size, &ptr, US"\"", 1);
849
850 /* Free the values */
851
852 ldap_value_free(CSS firstval);
853 }
854 }
855
856 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
857
858 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
859 to be freed. UMich LDAP stores them in static storage and does not require
860 this. */
861
862 ldap_memfree(attr);
863 #endif
864 } /* End "for" loop for extracting attributes from an entry */
865 } /* End "for" loop for extracting entries from a result */
866
867 /* Free the result */
868
869 ldap_msgfree(result);
870 result = NULL;
871 } /* End "while" loop for multiple results */
872
873 /* Terminate the dynamic string that we have built and reclaim unused store */
874
875 if (data != NULL)
876 {
877 data[ptr] = 0;
878 store_reset(data + ptr + 1);
879 }
880
881 /* Copy the last dn into eldap_dn */
882
883 if (dn != NULL)
884 {
885 eldap_dn = string_copy(dn);
886 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
887 ldap_memfree(dn);
888 #else /* OPENLDAP 1, UMich, Solaris */
889 free(dn);
890 #endif
891 }
892
893 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
894
895 if (rc == 0)
896 {
897 *errmsg = US"ldap_result timed out";
898 goto RETURN_ERROR;
899 }
900
901 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
902 provide you with a message". Other error states seem to exist where
903 ldap_result() didn't give us any message from the server at all, leaving result
904 set to NULL. Apparently, "the error parameters of the LDAP session handle will
905 be set accordingly". That's the best we can do to retrieve an error status; we
906 can't use functions like ldap_result2error because they parse a message from
907 the server, which we didn't get.
908
909 Annoyingly, the different implementations of LDAP have gone for different
910 methods of handling error codes and generating error messages. */
911
912 if (rc == -1 || result == NULL)
913 {
914 int err;
915 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
916
917 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
918 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
919 *errmsg = string_sprintf("ldap_result failed: %d, %s",
920 err, ldap_err2string(err));
921
922 #elif defined LDAP_LIB_NETSCAPE
923 /* Dubious (surely 'matched' is spurious here?) */
924 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
925 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
926
927 #else /* UMich LDAP aka OpenLDAP 1.x */
928 *errmsg = string_sprintf("ldap_result failed: %d, %s",
929 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
930 #endif
931
932 goto RETURN_ERROR;
933 }
934
935 /* A return code that isn't -1 doesn't necessarily mean there were no problems
936 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
937 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
938 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
939 we don't provide that functionality when we can't. :-) */
940
941 if (rc != LDAP_RES_SEARCH_RESULT
942 #ifdef LDAP_RES_SEARCH_REFERENCE
943 && rc != LDAP_RES_SEARCH_REFERENCE
944 #endif
945 )
946 {
947 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
948 goto RETURN_ERROR;
949 }
950
951 /* We have a result message from the server. This doesn't yet mean all is well.
952 We need to parse the message to find out exactly what's happened. */
953
954 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
955 ldap_rc = rc;
956 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
957 CSS &error2, NULL, NULL, 0);
958 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
959 if (ldap_parse_rc < 0 &&
960 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
961 #ifdef LDAP_RES_SEARCH_REFERENCE
962 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
963 #endif
964 ))
965 {
966 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
967 goto RETURN_ERROR;
968 }
969 error1 = US ldap_err2string(rc);
970
971 #elif defined LDAP_LIB_NETSCAPE
972 /* Dubious (it doesn't reference 'result' at all!) */
973 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
974
975 #else /* UMich LDAP aka OpenLDAP 1.x */
976 rc = ldap_result2error(lcp->ld, result, 0);
977 error1 = ldap_err2string(rc);
978 error2 = lcp->ld->ld_error;
979 matched = lcp->ld->ld_matched;
980 #endif
981
982 /* Process the status as follows:
983
984 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
985 truncated result list.
986
987 (2) If we get LDAP_RES_SEARCH_REFERENCE, also just carry on. This was a
988 submitted patch that is reported to "do the right thing" with Solaris
989 LDAP libraries. (The problem it addresses apparently does not occur with
990 Open LDAP.)
991
992 (3) The range of errors defined by LDAP_NAME_ERROR generally mean "that
993 object does not, or cannot, exist in the database". For those cases we
994 fail the lookup.
995
996 (4) All other non-successes here are treated as some kind of problem with
997 the lookup, so return DEFER (which is the default in error_yield).
998 */
999
1000 DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
1001 rc, ldap_err2string(rc));
1002
1003 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED
1004 #ifdef LDAP_RES_SEARCH_REFERENCE
1005 && rc != LDAP_RES_SEARCH_REFERENCE
1006 #endif
1007 )
1008 {
1009 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
1010 rc,
1011 (error1 != NULL)? error1 : US"",
1012 (error2 != NULL && error2[0] != 0)? US"/" : US"",
1013 (error2 != NULL)? error2 : US"",
1014 (matched != NULL && matched[0] != 0)? US"/" : US"",
1015 (matched != NULL)? matched : US"");
1016
1017 #if defined LDAP_NAME_ERROR
1018 if (LDAP_NAME_ERROR(rc))
1019 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
1020 if (NAME_ERROR(rc))
1021 #else
1022 if (rc == LDAP_NO_SUCH_OBJECT)
1023 #endif
1024
1025 {
1026 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
1027 error_yield = FAIL;
1028 }
1029 goto RETURN_ERROR;
1030 }
1031
1032 /* The search succeeded. Check if we have too many results */
1033
1034 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
1035 {
1036 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
1037 "(filter not specific enough?)", rescount);
1038 goto RETURN_ERROR_BREAK;
1039 }
1040
1041 /* Check if we have too few (zero) entries */
1042
1043 if (rescount < 1)
1044 {
1045 *errmsg = string_sprintf("LDAP search: no results");
1046 error_yield = FAIL;
1047 goto RETURN_ERROR_BREAK;
1048 }
1049
1050 /* If an entry was found, but it had no attributes, we behave as if no entries
1051 were found, that is, the lookup failed. */
1052
1053 if (!attribute_found)
1054 {
1055 *errmsg = US"LDAP search: found no attributes";
1056 error_yield = FAIL;
1057 goto RETURN_ERROR;
1058 }
1059
1060 /* Otherwise, it's all worked */
1061
1062 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
1063 *res = data;
1064
1065 RETURN_OK:
1066 if (result != NULL) ldap_msgfree(result);
1067 ldap_free_urldesc(ludp);
1068 return OK;
1069
1070 /* Error returns */
1071
1072 RETURN_ERROR_BREAK:
1073 *defer_break = TRUE;
1074
1075 RETURN_ERROR:
1076 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1077
1078 RETURN_ERROR_NOMSG:
1079 if (result != NULL) ldap_msgfree(result);
1080 if (ludp != NULL) ldap_free_urldesc(ludp);
1081
1082 #if defined LDAP_LIB_OPENLDAP2
1083 if (error2 != NULL) ldap_memfree(error2);
1084 if (matched != NULL) ldap_memfree(matched);
1085 #endif
1086
1087 return error_yield;
1088 }
1089
1090
1091
1092 /*************************************************
1093 * Internal search control function *
1094 *************************************************/
1095
1096 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
1097 and eldapm_find() with a difference in the "search_type" argument. It controls
1098 calls to perform_ldap_search() which actually does the work. We call that
1099 repeatedly for certain types of defer in the case when the URL contains no host
1100 name and eldap_default_servers is set to a list of servers to try. This gives
1101 more control than just passing over a list of hosts to ldap_open() because it
1102 handles other kinds of defer as well as just a failure to open. Note that the
1103 URL is defined to contain either zero or one "hostport" only.
1104
1105 Parameter data in addition to the URL can be passed as preceding text in the
1106 string, as items of the form XXX=yyy. The URL itself can be detected because it
1107 must begin "ldapx://", where x is empty, s, or i.
1108
1109 Arguments:
1110 ldap_url the URL to be looked up, optionally preceded by other parameter
1111 settings
1112 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
1113 SEARCH_LDAP_SINGLE allows values from one entry only
1114 SEARCH_LDAP_DN gets the DN from one entry
1115 res set to point at the result
1116 errmsg set to point a message if result is not OK
1117
1118 Returns: OK or FAIL or DEFER
1119 */
1120
1121 static int
1122 control_ldap_search(uschar *ldap_url, int search_type, uschar **res,
1123 uschar **errmsg)
1124 {
1125 BOOL defer_break = FALSE;
1126 int timelimit = LDAP_NO_LIMIT;
1127 int sizelimit = LDAP_NO_LIMIT;
1128 int tcplimit = 0;
1129 int sep = 0;
1130 int dereference = LDAP_DEREF_NEVER;
1131 void* referrals = LDAP_OPT_ON;
1132 uschar *url = ldap_url;
1133 uschar *p;
1134 uschar *user = NULL;
1135 uschar *password = NULL;
1136 uschar *local_servers = NULL;
1137 uschar *server, *list;
1138 uschar buffer[512];
1139
1140 while (isspace(*url)) url++;
1141
1142 /* Until the string begins "ldap", search for the other parameter settings that
1143 are recognized. They are of the form NAME=VALUE, with the value being
1144 optionally double-quoted. There must still be a space after it, however. No
1145 NAME has the value "ldap". */
1146
1147 while (strncmpic(url, US"ldap", 4) != 0)
1148 {
1149 uschar *name = url;
1150 while (*url != 0 && *url != '=') url++;
1151 if (*url == '=')
1152 {
1153 int namelen;
1154 uschar *value;
1155 namelen = ++url - name;
1156 value = string_dequote(&url);
1157 if (isspace(*url))
1158 {
1159 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1160 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1161 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1162 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1163 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1164 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1165 else if (strncmpic(name, US"SERVERS=", namelen) == 0) local_servers = value;
1166
1167 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1168
1169 #ifdef LDAP_OPT_DEREF
1170 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1171 {
1172 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1173 else if (strcmpic(value, US"searching") == 0)
1174 dereference = LDAP_DEREF_SEARCHING;
1175 else if (strcmpic(value, US"finding") == 0)
1176 dereference = LDAP_DEREF_FINDING;
1177 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1178 }
1179 #else
1180 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1181 {
1182 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1183 "library - cannot use \"dereference\"");
1184 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1185 return DEFER;
1186 }
1187 #endif
1188
1189 #ifdef LDAP_OPT_REFERRALS
1190 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1191 {
1192 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1193 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1194 else
1195 {
1196 *errmsg = string_sprintf("LDAP option REFERRALS is not \"follow\" "
1197 "or \"nofollow\"");
1198 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1199 return DEFER;
1200 }
1201 }
1202 #else
1203 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1204 {
1205 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1206 "library - cannot use \"referrals\"");
1207 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1208 return DEFER;
1209 }
1210 #endif
1211
1212 else
1213 {
1214 *errmsg =
1215 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1216 namelen, name);
1217 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1218 return DEFER;
1219 }
1220 while (isspace(*url)) url++;
1221 continue;
1222 }
1223 }
1224 *errmsg = US"malformed parameter setting precedes LDAP URL";
1225 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1226 return DEFER;
1227 }
1228
1229 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1230 but it seems that not all behave like this. The DN for the user is often the
1231 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1232 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1233 far too complicated. */
1234
1235 if (user != NULL)
1236 {
1237 uschar *s;
1238 uschar *t = user;
1239 for (s = user; *s != 0; s++)
1240 {
1241 int c, d;
1242 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1243 {
1244 c = tolower(c);
1245 d = tolower(d);
1246 *t++ =
1247 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1248 ((d >= 'a')? (10 + d - 'a') : d - '0');
1249 s += 2;
1250 }
1251 else *t++ = *s;
1252 }
1253 *t = 0;
1254 }
1255
1256 DEBUG(D_lookup)
1257 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1258 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1259 tcplimit, dereference, (referrals == LDAP_OPT_ON)? "on" : "off");
1260
1261 /* If the request is just to check authentication, some credentials must
1262 be given. The password must not be empty because LDAP binds with an empty
1263 password are considered anonymous, and will succeed on most installations. */
1264
1265 if (search_type == SEARCH_LDAP_AUTH)
1266 {
1267 if (user == NULL || password == NULL)
1268 {
1269 *errmsg = US"ldapauth lookups must specify the username and password";
1270 return DEFER;
1271 }
1272 if (password[0] == 0)
1273 {
1274 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1275 return FAIL;
1276 }
1277 }
1278
1279 /* Check for valid ldap url starters */
1280
1281 p = url + 4;
1282 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1283 if (Ustrncmp(p, "://", 3) != 0)
1284 {
1285 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1286 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1287 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1288 return DEFER;
1289 }
1290
1291 /* No default servers, or URL contains a server name: just one attempt */
1292
1293 if ((eldap_default_servers == NULL && local_servers == NULL) || p[3] != '/')
1294 {
1295 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1296 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1297 referrals);
1298 }
1299
1300 /* Loop through the default servers until OK or FAIL. Use local_servers list
1301 * if defined in the lookup, otherwise use the global default list */
1302 list = (local_servers == NULL) ? eldap_default_servers : local_servers;
1303 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1304 {
1305 int rc;
1306 int port = 0;
1307 uschar *colon = Ustrchr(server, ':');
1308 if (colon != NULL)
1309 {
1310 *colon = 0;
1311 port = Uatoi(colon+1);
1312 }
1313 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1314 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1315 referrals);
1316 if (rc != DEFER || defer_break) return rc;
1317 }
1318
1319 return DEFER;
1320 }
1321
1322
1323
1324 /*************************************************
1325 * Find entry point *
1326 *************************************************/
1327
1328 /* See local README for interface description. The different kinds of search
1329 are handled by a common function, with a flag to differentiate between them.
1330 The handle and filename arguments are not used. */
1331
1332 static int
1333 eldap_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1334 uschar **result, uschar **errmsg, BOOL *do_cache)
1335 {
1336 /* Keep picky compilers happy */
1337 do_cache = do_cache;
1338 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1339 }
1340
1341 static int
1342 eldapm_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1343 uschar **result, uschar **errmsg, BOOL *do_cache)
1344 {
1345 /* Keep picky compilers happy */
1346 do_cache = do_cache;
1347 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1348 }
1349
1350 static int
1351 eldapdn_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1352 uschar **result, uschar **errmsg, BOOL *do_cache)
1353 {
1354 /* Keep picky compilers happy */
1355 do_cache = do_cache;
1356 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1357 }
1358
1359 int
1360 eldapauth_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1361 uschar **result, uschar **errmsg, BOOL *do_cache)
1362 {
1363 /* Keep picky compilers happy */
1364 do_cache = do_cache;
1365 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1366 }
1367
1368
1369
1370 /*************************************************
1371 * Open entry point *
1372 *************************************************/
1373
1374 /* See local README for interface description. */
1375
1376 static void *
1377 eldap_open(uschar *filename, uschar **errmsg)
1378 {
1379 return (void *)(1); /* Just return something non-null */
1380 }
1381
1382
1383
1384 /*************************************************
1385 * Tidy entry point *
1386 *************************************************/
1387
1388 /* See local README for interface description.
1389 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1390
1391 static void
1392 eldap_tidy(void)
1393 {
1394 LDAP_CONNECTION *lcp = NULL;
1395 eldap_dn = NULL;
1396
1397 while ((lcp = ldap_connections) != NULL)
1398 {
1399 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1400 lcp->port);
1401 if(lcp->bound == TRUE)
1402 ldap_unbind(lcp->ld);
1403 ldap_connections = lcp->next;
1404 }
1405 }
1406
1407
1408
1409 /*************************************************
1410 * Quote entry point *
1411 *************************************************/
1412
1413 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1414 quoting have to be done: LDAP quoting, and URL quoting. The current
1415 specification is the result of a suggestion by Brian Candler. It recognizes
1416 two separate cases:
1417
1418 (1) For text that appears in a search filter, the following escapes are
1419 required (see RFC 2254):
1420
1421 * -> \2A
1422 ( -> \28
1423 ) -> \29
1424 \ -> \5C
1425 NULL -> \00
1426
1427 Then the entire filter text must be URL-escaped. This kind of quoting is
1428 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1429 in the input string, because that's a terminator.
1430
1431 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1432
1433 , + " \ < > ;
1434
1435 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1436 must be escaped, as must a leading #. Then the string must be URL-quoted.
1437 This type of quoting is implemented by ${quote_ldap_dn:....}.
1438
1439 For URL quoting, the only characters that need not be quoted are the
1440 alphamerics and
1441
1442 ! $ ' ( ) * + - . _
1443
1444 All the others must be hexified and preceded by %. This includes the
1445 backslashes used for LDAP quoting.
1446
1447 For a DN that is given in the USER parameter for authentication, we need the
1448 same initial quoting as (2) but in this case, the result must NOT be
1449 URL-escaped, because it isn't a URL. The way this is handled is by
1450 de-URL-quoting the text when processing the USER parameter in
1451 control_ldap_search() above. That means that the same quote operator can be
1452 used. This has the additional advantage that spaces in the DN won't cause
1453 parsing problems. For example:
1454
1455 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1456
1457 should be safe if there are spaces in $1.
1458
1459
1460 Arguments:
1461 s the string to be quoted
1462 opt additional option text or NULL if none
1463 only "dn" is recognized
1464
1465 Returns: the processed string or NULL for a bad option
1466 */
1467
1468
1469
1470 /* The characters in this string, together with alphanumerics, never need
1471 quoting in any way. */
1472
1473 #define ALWAYS_LITERAL "!$'-._"
1474
1475 /* The special characters in this string do not need to be URL-quoted. The set
1476 is a bit larger than the general literals. */
1477
1478 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1479
1480 /* The following macros define the characters that are quoted by quote_ldap and
1481 quote_ldap_dn, respectively. */
1482
1483 #define LDAP_QUOTE "*()\\"
1484 #define LDAP_DN_QUOTE ",+\"\\<>;"
1485
1486
1487
1488 static uschar *
1489 eldap_quote(uschar *s, uschar *opt)
1490 {
1491 register int c;
1492 int count = 0;
1493 int len = 0;
1494 BOOL dn = FALSE;
1495 uschar *t = s;
1496 uschar *quoted;
1497
1498 /* Test for a DN quotation. */
1499
1500 if (opt != NULL)
1501 {
1502 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1503 dn = TRUE;
1504 }
1505
1506 /* Compute how much extra store we need for the string. This doesn't have to be
1507 exact as long as it isn't an underestimate. The worst case is the addition of 5
1508 extra bytes for a single character. This occurs for certain characters in DNs,
1509 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1510 possibly escaped character. The really fast way would be just to test for
1511 non-alphanumerics, but it is probably better to spot a few others that are
1512 never escaped, because if there are no specials at all, we can avoid copying
1513 the string. */
1514
1515 while ((c = *t++) != 0)
1516 {
1517 len++;
1518 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1519 }
1520 if (count == 0) return s;
1521
1522 /* Get sufficient store to hold the quoted string */
1523
1524 t = quoted = store_get(len + count + 1);
1525
1526 /* Handle plain quote_ldap */
1527
1528 if (!dn)
1529 {
1530 while ((c = *s++) != 0)
1531 {
1532 if (!isalnum(c))
1533 {
1534 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1535 {
1536 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1537 t += 5;
1538 continue;
1539 }
1540 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1541 {
1542 sprintf(CS t, "%%%02X", c);
1543 t += 3;
1544 continue;
1545 }
1546 }
1547 *t++ = c; /* unquoted character */
1548 }
1549 }
1550
1551 /* Handle quote_ldap_dn */
1552
1553 else
1554 {
1555 uschar *ss = s + len;
1556
1557 /* Find the last char before any trailing spaces */
1558
1559 while (ss > s && ss[-1] == ' ') ss--;
1560
1561 /* Quote leading spaces and sharps */
1562
1563 for (; s < ss; s++)
1564 {
1565 if (*s != ' ' && *s != '#') break;
1566 sprintf(CS t, "%%5C%%%02X", *s);
1567 t += 6;
1568 }
1569
1570 /* Handle the rest of the string, up to the trailing spaces */
1571
1572 while (s < ss)
1573 {
1574 c = *s++;
1575 if (!isalnum(c))
1576 {
1577 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1578 {
1579 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1580 t += 3; /* fall through to check URL */
1581 }
1582 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1583 {
1584 sprintf(CS t, "%%%02X", c);
1585 t += 3;
1586 continue;
1587 }
1588 }
1589 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1590 }
1591
1592 /* Handle the trailing spaces */
1593
1594 while (*ss++ != 0)
1595 {
1596 Ustrncpy(t, "%5C%20", 6);
1597 t += 6;
1598 }
1599 }
1600
1601 /* Terminate the new string and return */
1602
1603 *t = 0;
1604 return quoted;
1605 }
1606
1607
1608
1609 /*************************************************
1610 * Version reporting entry point *
1611 *************************************************/
1612
1613 /* See local README for interface description. */
1614
1615 #include "../version.h"
1616
1617 void
1618 ldap_version_report(FILE *f)
1619 {
1620 #ifdef DYNLOOKUP
1621 fprintf(f, "Library version: LDAP: Exim version %s\n", EXIM_VERSION_STR);
1622 #endif
1623 }
1624
1625
1626 static lookup_info ldap_lookup_info = {
1627 US"ldap", /* lookup name */
1628 lookup_querystyle, /* query-style lookup */
1629 eldap_open, /* open function */
1630 NULL, /* check function */
1631 eldap_find, /* find function */
1632 NULL, /* no close function */
1633 eldap_tidy, /* tidy function */
1634 eldap_quote, /* quoting function */
1635 ldap_version_report /* version reporting */
1636 };
1637
1638 static lookup_info ldapdn_lookup_info = {
1639 US"ldapdn", /* lookup name */
1640 lookup_querystyle, /* query-style lookup */
1641 eldap_open, /* sic */ /* open function */
1642 NULL, /* check function */
1643 eldapdn_find, /* find function */
1644 NULL, /* no close function */
1645 eldap_tidy, /* sic */ /* tidy function */
1646 eldap_quote, /* sic */ /* quoting function */
1647 NULL /* no version reporting (redundant) */
1648 };
1649
1650 static lookup_info ldapm_lookup_info = {
1651 US"ldapm", /* lookup name */
1652 lookup_querystyle, /* query-style lookup */
1653 eldap_open, /* sic */ /* open function */
1654 NULL, /* check function */
1655 eldapm_find, /* find function */
1656 NULL, /* no close function */
1657 eldap_tidy, /* sic */ /* tidy function */
1658 eldap_quote, /* sic */ /* quoting function */
1659 NULL /* no version reporting (redundant) */
1660 };
1661
1662 #ifdef DYNLOOKUP
1663 #define ldap_lookup_module_info _lookup_module_info
1664 #endif
1665
1666 static lookup_info *_lookup_list[] = { &ldap_lookup_info, &ldapdn_lookup_info, &ldapm_lookup_info };
1667 lookup_module_info ldap_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
1668
1669 /* End of lookups/ldap.c */