Make ldap_require_cert work (not segfault).
[exim.git] / src / src / lookups / ldap.c
1 /* $Cambridge: exim/src/src/lookups/ldap.c,v 1.15 2009/11/16 19:50:38 nm4 Exp $ */
2
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
6
7 /* Copyright (c) University of Cambridge 1995 - 2009 */
8 /* See the file NOTICE for conditions of use and distribution. */
9
10 /* Many thanks to Stuart Lynne for contributing the original code for this
11 driver. Further contibutions from Michael Haardt, Brian Candler, Barry
12 Pederson, Peter Savitch and Christian Kellner. Particular thanks to Brian for
13 researching how to handle the different kinds of error. */
14
15
16 #include "../exim.h"
17 #include "lf_functions.h"
18
19
20 /* Include LDAP headers. The code below uses some "old" LDAP interfaces that
21 are deprecated in OpenLDAP. I don't know their status in other LDAP
22 implementations. LDAP_DEPRECATED causes their prototypes to be defined in
23 ldap.h. */
24
25 #define LDAP_DEPRECATED 1
26
27 #include <lber.h>
28 #include <ldap.h>
29
30
31 /* Annoyingly, the different LDAP libraries handle errors in different ways,
32 and some other things too. There doesn't seem to be an automatic way of
33 distinguishing between them. Local/Makefile should contain a setting of
34 LDAP_LIB_TYPE, which in turn causes appropriate macros to be defined for the
35 different kinds. Those that matter are:
36
37 LDAP_LIB_NETSCAPE
38 LDAP_LIB_SOLARIS with synonym LDAP_LIB_SOLARIS7
39 LDAP_LIB_OPENLDAP2
40
41 These others may be defined, but are in fact the default, so are not tested:
42
43 LDAP_LIB_UMICHIGAN
44 LDAP_LIB_OPENLDAP1
45 */
46
47 #if defined(LDAP_LIB_SOLARIS7) && ! defined(LDAP_LIB_SOLARIS)
48 #define LDAP_LIB_SOLARIS
49 #endif
50
51
52 /* Just in case LDAP_NO_LIMIT is not defined by some of these libraries. */
53
54 #ifndef LDAP_NO_LIMIT
55 #define LDAP_NO_LIMIT 0
56 #endif
57
58
59 /* Just in case LDAP_DEREF_NEVER is not defined */
60
61 #ifndef LDAP_DEREF_NEVER
62 #define LDAP_DEREF_NEVER 0
63 #endif
64
65
66 /* Four types of LDAP search are implemented */
67
68 #define SEARCH_LDAP_MULTIPLE 0 /* Get attributes from multiple entries */
69 #define SEARCH_LDAP_SINGLE 1 /* Get attributes from one entry only */
70 #define SEARCH_LDAP_DN 2 /* Get just the DN from one entry */
71 #define SEARCH_LDAP_AUTH 3 /* Just checking for authentication */
72
73 /* In all 4 cases, the DN is left in $ldap_dn (which post-dates the
74 SEARCH_LDAP_DN lookup). */
75
76
77 /* Structure and anchor for caching connections. */
78
79 typedef struct ldap_connection {
80 struct ldap_connection *next;
81 uschar *host;
82 uschar *user;
83 uschar *password;
84 BOOL bound;
85 int port;
86 LDAP *ld;
87 } LDAP_CONNECTION;
88
89 static LDAP_CONNECTION *ldap_connections = NULL;
90
91
92
93 /*************************************************
94 * Internal search function *
95 *************************************************/
96
97 /* This is the function that actually does the work. It is called (indirectly
98 via control_ldap_search) from eldap_find(), eldapauth_find(), eldapdn_find(),
99 and eldapm_find(), with a difference in the "search_type" argument.
100
101 The case of eldapauth_find() is special in that all it does is do
102 authentication, returning OK or FAIL as appropriate. This isn't used as a
103 lookup. Instead, it is called from expand.c as an expansion condition test.
104
105 The DN from a successful lookup is placed in $ldap_dn. This feature postdates
106 the provision of the SEARCH_LDAP_DN facility for returning just the DN as the
107 data.
108
109 Arguments:
110 ldap_url the URL to be looked up
111 server server host name, when URL contains none
112 s_port server port, used when URL contains no name
113 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
114 SEARCH_LDAP_SINGLE allows values from one entry only
115 SEARCH_LDAP_DN gets the DN from one entry
116 res set to point at the result (not used for ldapauth)
117 errmsg set to point a message if result is not OK
118 defer_break set TRUE if no more servers to be tried after a DEFER
119 user user name for authentication, or NULL
120 password password for authentication, or NULL
121 sizelimit max number of entries returned, or 0 for no limit
122 timelimit max time to wait, or 0 for no limit
123 tcplimit max time for network activity, e.g. connect, or 0 for OS default
124 deference the dereference option, which is one of
125 LDAP_DEREF_{NEVER,SEARCHING,FINDING,ALWAYS}
126 referrals the referral option, which is LDAP_OPT_ON or LDAP_OPT_OFF
127
128 Returns: OK or FAIL or DEFER
129 FAIL is given only if a lookup was performed successfully, but
130 returned no data.
131 */
132
133 static int
134 perform_ldap_search(uschar *ldap_url, uschar *server, int s_port, int search_type,
135 uschar **res, uschar **errmsg, BOOL *defer_break, uschar *user, uschar *password,
136 int sizelimit, int timelimit, int tcplimit, int dereference, void *referrals)
137 {
138 LDAPURLDesc *ludp = NULL;
139 LDAPMessage *result = NULL;
140 BerElement *ber;
141 LDAP_CONNECTION *lcp;
142
143 struct timeval timeout;
144 struct timeval *timeoutptr = NULL;
145
146 uschar *attr;
147 uschar **attrp;
148 uschar *data = NULL;
149 uschar *dn = NULL;
150 uschar *host;
151 uschar **values;
152 uschar **firstval;
153 uschar porttext[16];
154
155 uschar *error1 = NULL; /* string representation of errcode (static) */
156 uschar *error2 = NULL; /* error message from the server */
157 uschar *matched = NULL; /* partially matched DN */
158
159 int attr_count = 0;
160 int error_yield = DEFER;
161 int msgid;
162 int rc, ldap_rc, ldap_parse_rc;
163 int port;
164 int ptr = 0;
165 int rescount = 0;
166 int size = 0;
167 BOOL attribute_found = FALSE;
168 BOOL ldapi = FALSE;
169
170 DEBUG(D_lookup)
171 debug_printf("perform_ldap_search: ldap%s URL = \"%s\" server=%s port=%d "
172 "sizelimit=%d timelimit=%d tcplimit=%d\n",
173 (search_type == SEARCH_LDAP_MULTIPLE)? "m" :
174 (search_type == SEARCH_LDAP_DN)? "dn" :
175 (search_type == SEARCH_LDAP_AUTH)? "auth" : "",
176 ldap_url, server, s_port, sizelimit, timelimit, tcplimit);
177
178 /* Check if LDAP thinks the URL is a valid LDAP URL. We assume that if the LDAP
179 library that is in use doesn't recognize, say, "ldapi", it will barf here. */
180
181 if (!ldap_is_ldap_url(CS ldap_url))
182 {
183 *errmsg = string_sprintf("ldap_is_ldap_url: not an LDAP url \"%s\"\n",
184 ldap_url);
185 goto RETURN_ERROR_BREAK;
186 }
187
188 /* Parse the URL */
189
190 if ((rc = ldap_url_parse(CS ldap_url, &ludp)) != 0)
191 {
192 *errmsg = string_sprintf("ldap_url_parse: (error %d) parsing \"%s\"\n", rc,
193 ldap_url);
194 goto RETURN_ERROR_BREAK;
195 }
196
197 /* If the host name is empty, take it from the separate argument, if one is
198 given. OpenLDAP 2.0.6 sets an unset hostname to "" rather than empty, but
199 expects NULL later in ldap_init() to mean "default", annoyingly. In OpenLDAP
200 2.0.11 this has changed (it uses NULL). */
201
202 if ((ludp->lud_host == NULL || ludp->lud_host[0] == 0) && server != NULL)
203 {
204 host = server;
205 port = s_port;
206 }
207 else
208 {
209 host = US ludp->lud_host;
210 if (host != NULL && host[0] == 0) host = NULL;
211 port = ludp->lud_port;
212 }
213
214 DEBUG(D_lookup) debug_printf("after ldap_url_parse: host=%s port=%d\n",
215 host, port);
216
217 if (port == 0) port = LDAP_PORT; /* Default if none given */
218 sprintf(CS porttext, ":%d", port); /* For messages */
219
220 /* If the "host name" is actually a path, we are going to connect using a Unix
221 socket, regardless of whether "ldapi" was actually specified or not. This means
222 that a Unix socket can be declared in eldap_default_servers, and "traditional"
223 LDAP queries using just "ldap" can be used ("ldaps" is similarly overridden).
224 The path may start with "/" or it may already be escaped as "%2F" if it was
225 actually declared that way in eldap_default_servers. (I did it that way the
226 first time.) If the host name is not a path, the use of "ldapi" causes an
227 error, except in the default case. (But lud_scheme doesn't seem to exist in
228 older libraries.) */
229
230 if (host != NULL)
231 {
232 if ((host[0] == '/' || Ustrncmp(host, "%2F", 3) == 0))
233 {
234 ldapi = TRUE;
235 porttext[0] = 0; /* Remove port from messages */
236 }
237
238 #if defined LDAP_LIB_OPENLDAP2
239 else if (strncmp(ludp->lud_scheme, "ldapi", 5) == 0)
240 {
241 *errmsg = string_sprintf("ldapi requires an absolute path (\"%s\" given)",
242 host);
243 goto RETURN_ERROR;
244 }
245 #endif
246 }
247
248 /* Count the attributes; we need this later to tell us how to format results */
249
250 for (attrp = USS ludp->lud_attrs; attrp != NULL && *attrp != NULL; attrp++)
251 attr_count++;
252
253 /* See if we can find a cached connection to this host. The port is not
254 relevant for ldapi. The host name pointer is set to NULL if no host was given
255 (implying the library default), rather than to the empty string. Note that in
256 this case, there is no difference between ldap and ldapi. */
257
258 for (lcp = ldap_connections; lcp != NULL; lcp = lcp->next)
259 {
260 if ((host == NULL) != (lcp->host == NULL) ||
261 (host != NULL && strcmpic(lcp->host, host) != 0))
262 continue;
263 if (ldapi || port == lcp->port) break;
264 }
265
266 /* Use this network timeout in any requests. */
267
268 if (tcplimit > 0)
269 {
270 timeout.tv_sec = tcplimit;
271 timeout.tv_usec = 0;
272 timeoutptr = &timeout;
273 }
274
275 /* If no cached connection found, we must open a connection to the server. If
276 the server name is actually an absolute path, we set ldapi=TRUE above. This
277 requests connection via a Unix socket. However, as far as I know, only OpenLDAP
278 supports the use of sockets, and the use of ldap_initialize(). */
279
280 if (lcp == NULL)
281 {
282 LDAP *ld;
283
284
285 /* --------------------------- OpenLDAP ------------------------ */
286
287 /* There seems to be a preference under OpenLDAP for ldap_initialize()
288 instead of ldap_init(), though I have as yet been unable to find
289 documentation that says this. (OpenLDAP documentation is sparse to
290 non-existent). So we handle OpenLDAP differently here. Also, support for
291 ldapi seems to be OpenLDAP-only at present. */
292
293 #ifdef LDAP_LIB_OPENLDAP2
294
295 /* We now need an empty string for the default host. Get some store in which
296 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
297 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
298 than the host name + "ldaps:///" plus : and a port number, say 20 + the
299 length of the host name. What we get should accommodate both, easily. */
300
301 uschar *shost = (host == NULL)? US"" : host;
302 uschar *init_url = store_get(20 + 3 * Ustrlen(shost));
303 uschar *init_ptr;
304
305 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
306 contain the path name, with slashes escaped as %2F. */
307
308 if (ldapi)
309 {
310 int ch;
311 init_ptr = init_url + 8;
312 Ustrcpy(init_url, "ldapi://");
313 while ((ch = *shost++) != 0)
314 {
315 if (ch == '/')
316 {
317 Ustrncpy(init_ptr, "%2F", 3);
318 init_ptr += 3;
319 }
320 else *init_ptr++ = ch;
321 }
322 *init_ptr = 0;
323 }
324
325 /* This is not an ldapi call. Just build a URI with the protocol type, host
326 name, and port. */
327
328 else
329 {
330 init_ptr = Ustrchr(ldap_url, '/');
331 Ustrncpy(init_url, ldap_url, init_ptr - ldap_url);
332 init_ptr = init_url + (init_ptr - ldap_url);
333 sprintf(CS init_ptr, "//%s:%d/", shost, port);
334 }
335
336 /* Call ldap_initialize() and check the result */
337
338 DEBUG(D_lookup) debug_printf("ldap_initialize with URL %s\n", init_url);
339 rc = ldap_initialize(&ld, CS init_url);
340 if (rc != LDAP_SUCCESS)
341 {
342 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
343 rc, init_url);
344 goto RETURN_ERROR;
345 }
346 store_reset(init_url); /* Might as well save memory when we can */
347
348
349 /* ------------------------- Not OpenLDAP ---------------------- */
350
351 /* For libraries other than OpenLDAP, use ldap_init(). */
352
353 #else /* LDAP_LIB_OPENLDAP2 */
354 ld = ldap_init(CS host, port);
355 #endif /* LDAP_LIB_OPENLDAP2 */
356
357 /* -------------------------------------------------------------- */
358
359
360 /* Handle failure to initialize */
361
362 if (ld == NULL)
363 {
364 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
365 host, porttext, strerror(errno));
366 goto RETURN_ERROR;
367 }
368
369 /* Set the TCP connect time limit if available. This is something that is
370 in Netscape SDK v4.1; I don't know about other libraries. */
371
372 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
373 if (tcplimit > 0)
374 {
375 int timeout1000 = tcplimit*1000;
376 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
377 }
378 else
379 {
380 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
381 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&notimeout);
382 }
383 #endif
384
385 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
386
387 #ifdef LDAP_OPT_NETWORK_TIMEOUT
388 if (tcplimit > 0)
389 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
390 #endif
391
392 /* I could not get TLS to work until I set the version to 3. That version
393 seems to be the default nowadays. The RFC is dated 1997, so I would hope
394 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
395 been set, go for v3 if we can. */
396
397 if (eldap_version < 0)
398 {
399 #ifdef LDAP_VERSION3
400 eldap_version = LDAP_VERSION3;
401 #else
402 eldap_version = 2;
403 #endif
404 }
405
406 #ifdef LDAP_OPT_PROTOCOL_VERSION
407 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
408 #endif
409
410 DEBUG(D_lookup) debug_printf("initialized for LDAP (v%d) server %s%s\n",
411 eldap_version, host, porttext);
412
413 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
414 for "ldaps" and soft otherwise. */
415
416 #ifdef LDAP_OPT_X_TLS
417 if (!ldapi)
418 {
419 int tls_option;
420 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
421 {
422 tls_option = LDAP_OPT_X_TLS_HARD;
423 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_HARD set\n");
424 }
425 else
426 {
427 tls_option = LDAP_OPT_X_TLS_TRY;
428 DEBUG(D_lookup) debug_printf("LDAP_OPT_X_TLS_TRY set\n");
429 }
430 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
431 }
432 #endif /* LDAP_OPT_X_TLS */
433
434 #ifdef LDAP_OPT_X_TLS_CACERTFILE
435 if (eldap_ca_cert_file != NULL)
436 {
437 ldap_set_option(ld, LDAP_OPT_X_TLS_CACERTFILE, eldap_ca_cert_file);
438 }
439 #endif
440 #ifdef LDAP_OPT_X_TLS_CACERTDIR
441 if (eldap_ca_cert_dir != NULL)
442 {
443 ldap_set_option(ld, LDAP_OPT_X_TLS_CACERTDIR, eldap_ca_cert_dir);
444 }
445 #endif
446 #ifdef LDAP_OPT_X_TLS_CERTFILE
447 if (eldap_cert_file != NULL)
448 {
449 ldap_set_option(ld, LDAP_OPT_X_TLS_CERTFILE, eldap_cert_file);
450 }
451 #endif
452 #ifdef LDAP_OPT_X_TLS_KEYFILE
453 if (eldap_cert_key != NULL)
454 {
455 ldap_set_option(ld, LDAP_OPT_X_TLS_KEYFILE, eldap_cert_key);
456 }
457 #endif
458 #ifdef LDAP_OPT_X_TLS_CIPHER_SUITE
459 if (eldap_cipher_suite != NULL)
460 {
461 ldap_set_option(ld, LDAP_OPT_X_TLS_CIPHER_SUITE, eldap_cipher_suite);
462 }
463 #endif
464 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
465 if (eldap_require_cert != NULL)
466 {
467 int cert_option = LDAP_OPT_X_TLS_NEVER;
468 if (Ustrcmp(eldap_require_cert, "hard") == 0)
469 {
470 cert_option = LDAP_OPT_X_TLS_HARD;
471 }
472 else if (Ustrcmp(eldap_require_cert, "demand") == 0)
473 {
474 cert_option = LDAP_OPT_X_TLS_DEMAND;
475 }
476 else if (Ustrcmp(eldap_require_cert, "allow") == 0)
477 {
478 cert_option = LDAP_OPT_X_TLS_ALLOW;
479 }
480 else if (Ustrcmp(eldap_require_cert, "try") == 0)
481 {
482 cert_option = LDAP_OPT_X_TLS_TRY;
483 }
484 ldap_set_option(ld, LDAP_OPT_X_TLS_REQUIRE_CERT, &cert_option);
485 }
486 #endif
487
488 /* Now add this connection to the chain of cached connections */
489
490 lcp = store_get(sizeof(LDAP_CONNECTION));
491 lcp->host = (host == NULL)? NULL : string_copy(host);
492 lcp->bound = FALSE;
493 lcp->user = NULL;
494 lcp->password = NULL;
495 lcp->port = port;
496 lcp->ld = ld;
497 lcp->next = ldap_connections;
498 ldap_connections = lcp;
499 }
500
501 /* Found cached connection */
502
503 else
504 {
505 DEBUG(D_lookup)
506 debug_printf("re-using cached connection to LDAP server %s%s\n",
507 host, porttext);
508 }
509
510 /* Bind with the user/password supplied, or an anonymous bind if these values
511 are NULL, unless a cached connection is already bound with the same values. */
512
513 if (!lcp->bound ||
514 (lcp->user == NULL && user != NULL) ||
515 (lcp->user != NULL && user == NULL) ||
516 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
517 (lcp->password == NULL && password != NULL) ||
518 (lcp->password != NULL && password == NULL) ||
519 (lcp->password != NULL && password != NULL &&
520 Ustrcmp(lcp->password, password) != 0))
521 {
522 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
523 (lcp->bound)? "re-" : "", user, password);
524 if (eldap_start_tls)
525 {
526 ldap_start_tls_s(lcp->ld, NULL, NULL);
527 }
528 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
529 == -1)
530 {
531 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
532 "%s%s - ldap_bind() returned -1", host, porttext);
533 goto RETURN_ERROR;
534 }
535
536 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
537 {
538 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
539 "%s%s - LDAP error: %s", host, porttext,
540 rc == -1 ? "result retrieval failed" : "timeout" );
541 result = NULL;
542 goto RETURN_ERROR;
543 }
544
545 rc = ldap_result2error( lcp->ld, result, 0 );
546
547 /* Invalid credentials when just checking credentials returns FAIL. This
548 stops any further servers being tried. */
549
550 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
551 {
552 DEBUG(D_lookup)
553 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
554 error_yield = FAIL;
555 goto RETURN_ERROR_NOMSG;
556 }
557
558 /* Otherwise we have a problem that doesn't stop further servers from being
559 tried. */
560
561 if (rc != LDAP_SUCCESS)
562 {
563 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
564 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
565 goto RETURN_ERROR;
566 }
567
568 /* Successful bind */
569
570 lcp->bound = TRUE;
571 lcp->user = (user == NULL)? NULL : string_copy(user);
572 lcp->password = (password == NULL)? NULL : string_copy(password);
573
574 ldap_msgfree(result);
575 result = NULL;
576 }
577
578 /* If we are just checking credentials, return OK. */
579
580 if (search_type == SEARCH_LDAP_AUTH)
581 {
582 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
583 goto RETURN_OK;
584 }
585
586 /* Before doing the search, set the time and size limits (if given). Here again
587 the different implementations of LDAP have chosen to do things differently. */
588
589 #if defined(LDAP_OPT_SIZELIMIT)
590 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
591 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
592 #else
593 lcp->ld->ld_sizelimit = sizelimit;
594 lcp->ld->ld_timelimit = timelimit;
595 #endif
596
597 /* Similarly for dereferencing aliases. Don't know if this is possible on
598 an LDAP library without LDAP_OPT_DEREF. */
599
600 #if defined(LDAP_OPT_DEREF)
601 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
602 #endif
603
604 /* Similarly for the referral setting; should the library follow referrals that
605 the LDAP server returns? The conditional is just in case someone uses a library
606 without it. */
607
608 #if defined(LDAP_OPT_REFERRALS)
609 ldap_set_option(lcp->ld, LDAP_OPT_REFERRALS, referrals);
610 #endif
611
612 /* Start the search on the server. */
613
614 DEBUG(D_lookup) debug_printf("Start search\n");
615
616 msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
617 ludp->lud_attrs, 0);
618
619 if (msgid == -1)
620 {
621 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
622 int err;
623 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
624 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
625 ldap_err2string(err));
626
627 #else
628 *errmsg = string_sprintf("ldap_search failed");
629 #endif
630
631 goto RETURN_ERROR;
632 }
633
634 /* Loop to pick up results as they come in, setting a timeout if one was
635 given. */
636
637 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
638 LDAP_RES_SEARCH_ENTRY)
639 {
640 LDAPMessage *e;
641
642 DEBUG(D_lookup) debug_printf("ldap_result loop\n");
643
644 for(e = ldap_first_entry(lcp->ld, result);
645 e != NULL;
646 e = ldap_next_entry(lcp->ld, e))
647 {
648 uschar *new_dn;
649 BOOL insert_space = FALSE;
650
651 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
652
653 rescount++; /* Count results */
654
655 /* Results for multiple entries values are separated by newlines. */
656
657 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
658
659 /* Get the DN from the last result. */
660
661 new_dn = US ldap_get_dn(lcp->ld, e);
662 if (new_dn != NULL)
663 {
664 if (dn != NULL)
665 {
666 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
667 ldap_memfree(dn);
668 #else /* OPENLDAP 1, UMich, Solaris */
669 free(dn);
670 #endif
671 }
672 /* Save for later */
673 dn = new_dn;
674 }
675
676 /* If the data we want is actually the DN rather than any attribute values,
677 (an "ldapdn" search) add it to the data string. If there are multiple
678 entries, the DNs will be concatenated, but we test for this case below, as
679 for SEARCH_LDAP_SINGLE, and give an error. */
680
681 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
682 { /* condition, because of the else */
683 if (new_dn != NULL) /* below, that's for the first only */
684 {
685 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
686 data[ptr] = 0;
687 attribute_found = TRUE;
688 }
689 }
690
691 /* Otherwise, loop through the entry, grabbing attribute values. If there's
692 only one attribute being retrieved, no attribute name is given, and the
693 result is not quoted. Multiple values are separated by (comma, space).
694 If more than one attribute is being retrieved, the data is given as a
695 sequence of name=value pairs, with the value always in quotes. If there are
696 multiple values, they are given within the quotes, comma separated. */
697
698 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
699 attr != NULL;
700 attr = US ldap_next_attribute(lcp->ld, e, ber))
701 {
702 if (attr[0] != 0)
703 {
704 /* Get array of values for this attribute. */
705
706 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
707 != NULL)
708 {
709 if (attr_count != 1)
710 {
711 if (insert_space)
712 data = string_cat(data, &size, &ptr, US" ", 1);
713 else
714 insert_space = TRUE;
715 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
716 data = string_cat(data, &size, &ptr, US"=\"", 2);
717 }
718
719 while (*values != NULL)
720 {
721 uschar *value = *values;
722 int len = Ustrlen(value);
723
724 DEBUG(D_lookup) debug_printf("LDAP attr loop %s:%s\n", attr, value);
725
726 if (values != firstval)
727 data = string_cat(data, &size, &ptr, US", ", 2);
728
729 /* For multiple attributes, the data is in quotes. We must escape
730 internal quotes, backslashes, newlines. */
731
732 if (attr_count != 1)
733 {
734 int j;
735 for (j = 0; j < len; j++)
736 {
737 if (value[j] == '\n')
738 data = string_cat(data, &size, &ptr, US"\\n", 2);
739 else
740 {
741 if (value[j] == '\"' || value[j] == '\\')
742 data = string_cat(data, &size, &ptr, US"\\", 1);
743 data = string_cat(data, &size, &ptr, value+j, 1);
744 }
745 }
746 }
747
748 /* For single attributes, copy the value verbatim */
749
750 else data = string_cat(data, &size, &ptr, value, len);
751
752 /* Move on to the next value */
753
754 values++;
755 attribute_found = TRUE;
756 }
757
758 /* Closing quote at the end of the data for a named attribute. */
759
760 if (attr_count != 1)
761 data = string_cat(data, &size, &ptr, US"\"", 1);
762
763 /* Free the values */
764
765 ldap_value_free(CSS firstval);
766 }
767 }
768
769 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
770
771 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
772 to be freed. UMich LDAP stores them in static storage and does not require
773 this. */
774
775 ldap_memfree(attr);
776 #endif
777 } /* End "for" loop for extracting attributes from an entry */
778 } /* End "for" loop for extracting entries from a result */
779
780 /* Free the result */
781
782 ldap_msgfree(result);
783 result = NULL;
784 } /* End "while" loop for multiple results */
785
786 /* Terminate the dynamic string that we have built and reclaim unused store */
787
788 if (data != NULL)
789 {
790 data[ptr] = 0;
791 store_reset(data + ptr + 1);
792 }
793
794 /* Copy the last dn into eldap_dn */
795
796 if (dn != NULL)
797 {
798 eldap_dn = string_copy(dn);
799 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
800 ldap_memfree(dn);
801 #else /* OPENLDAP 1, UMich, Solaris */
802 free(dn);
803 #endif
804 }
805
806 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
807
808 if (rc == 0)
809 {
810 *errmsg = US"ldap_result timed out";
811 goto RETURN_ERROR;
812 }
813
814 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
815 provide you with a message". Other error states seem to exist where
816 ldap_result() didn't give us any message from the server at all, leaving result
817 set to NULL. Apparently, "the error parameters of the LDAP session handle will
818 be set accordingly". That's the best we can do to retrieve an error status; we
819 can't use functions like ldap_result2error because they parse a message from
820 the server, which we didn't get.
821
822 Annoyingly, the different implementations of LDAP have gone for different
823 methods of handling error codes and generating error messages. */
824
825 if (rc == -1 || result == NULL)
826 {
827 int err;
828 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
829
830 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
831 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
832 *errmsg = string_sprintf("ldap_result failed: %d, %s",
833 err, ldap_err2string(err));
834
835 #elif defined LDAP_LIB_NETSCAPE
836 /* Dubious (surely 'matched' is spurious here?) */
837 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
838 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
839
840 #else /* UMich LDAP aka OpenLDAP 1.x */
841 *errmsg = string_sprintf("ldap_result failed: %d, %s",
842 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
843 #endif
844
845 goto RETURN_ERROR;
846 }
847
848 /* A return code that isn't -1 doesn't necessarily mean there were no problems
849 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
850 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
851 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
852 we don't provide that functionality when we can't. :-) */
853
854 if (rc != LDAP_RES_SEARCH_RESULT
855 #ifdef LDAP_RES_SEARCH_REFERENCE
856 && rc != LDAP_RES_SEARCH_REFERENCE
857 #endif
858 )
859 {
860 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
861 goto RETURN_ERROR;
862 }
863
864 /* We have a result message from the server. This doesn't yet mean all is well.
865 We need to parse the message to find out exactly what's happened. */
866
867 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
868 ldap_rc = rc;
869 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
870 CSS &error2, NULL, NULL, 0);
871 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
872 if (ldap_parse_rc < 0 &&
873 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
874 #ifdef LDAP_RES_SEARCH_REFERENCE
875 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
876 #endif
877 ))
878 {
879 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
880 goto RETURN_ERROR;
881 }
882 error1 = US ldap_err2string(rc);
883
884 #elif defined LDAP_LIB_NETSCAPE
885 /* Dubious (it doesn't reference 'result' at all!) */
886 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
887
888 #else /* UMich LDAP aka OpenLDAP 1.x */
889 rc = ldap_result2error(lcp->ld, result, 0);
890 error1 = ldap_err2string(rc);
891 error2 = lcp->ld->ld_error;
892 matched = lcp->ld->ld_matched;
893 #endif
894
895 /* Process the status as follows:
896
897 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
898 truncated result list.
899
900 (2) If we get LDAP_RES_SEARCH_REFERENCE, also just carry on. This was a
901 submitted patch that is reported to "do the right thing" with Solaris
902 LDAP libraries. (The problem it addresses apparently does not occur with
903 Open LDAP.)
904
905 (3) The range of errors defined by LDAP_NAME_ERROR generally mean "that
906 object does not, or cannot, exist in the database". For those cases we
907 fail the lookup.
908
909 (4) All other non-successes here are treated as some kind of problem with
910 the lookup, so return DEFER (which is the default in error_yield).
911 */
912
913 DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
914 rc, ldap_err2string(rc));
915
916 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED
917 #ifdef LDAP_RES_SEARCH_REFERENCE
918 && rc != LDAP_RES_SEARCH_REFERENCE
919 #endif
920 )
921 {
922 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
923 rc,
924 (error1 != NULL)? error1 : US"",
925 (error2 != NULL && error2[0] != 0)? US"/" : US"",
926 (error2 != NULL)? error2 : US"",
927 (matched != NULL && matched[0] != 0)? US"/" : US"",
928 (matched != NULL)? matched : US"");
929
930 #if defined LDAP_NAME_ERROR
931 if (LDAP_NAME_ERROR(rc))
932 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
933 if (NAME_ERROR(rc))
934 #else
935 if (rc == LDAP_NO_SUCH_OBJECT)
936 #endif
937
938 {
939 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
940 error_yield = FAIL;
941 }
942 goto RETURN_ERROR;
943 }
944
945 /* The search succeeded. Check if we have too many results */
946
947 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
948 {
949 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
950 "(filter not specific enough?)", rescount);
951 goto RETURN_ERROR_BREAK;
952 }
953
954 /* Check if we have too few (zero) entries */
955
956 if (rescount < 1)
957 {
958 *errmsg = string_sprintf("LDAP search: no results");
959 error_yield = FAIL;
960 goto RETURN_ERROR_BREAK;
961 }
962
963 /* If an entry was found, but it had no attributes, we behave as if no entries
964 were found, that is, the lookup failed. */
965
966 if (!attribute_found)
967 {
968 *errmsg = US"LDAP search: found no attributes";
969 error_yield = FAIL;
970 goto RETURN_ERROR;
971 }
972
973 /* Otherwise, it's all worked */
974
975 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
976 *res = data;
977
978 RETURN_OK:
979 if (result != NULL) ldap_msgfree(result);
980 ldap_free_urldesc(ludp);
981 return OK;
982
983 /* Error returns */
984
985 RETURN_ERROR_BREAK:
986 *defer_break = TRUE;
987
988 RETURN_ERROR:
989 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
990
991 RETURN_ERROR_NOMSG:
992 if (result != NULL) ldap_msgfree(result);
993 if (ludp != NULL) ldap_free_urldesc(ludp);
994
995 #if defined LDAP_LIB_OPENLDAP2
996 if (error2 != NULL) ldap_memfree(error2);
997 if (matched != NULL) ldap_memfree(matched);
998 #endif
999
1000 return error_yield;
1001 }
1002
1003
1004
1005 /*************************************************
1006 * Internal search control function *
1007 *************************************************/
1008
1009 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
1010 and eldapm_find() with a difference in the "search_type" argument. It controls
1011 calls to perform_ldap_search() which actually does the work. We call that
1012 repeatedly for certain types of defer in the case when the URL contains no host
1013 name and eldap_default_servers is set to a list of servers to try. This gives
1014 more control than just passing over a list of hosts to ldap_open() because it
1015 handles other kinds of defer as well as just a failure to open. Note that the
1016 URL is defined to contain either zero or one "hostport" only.
1017
1018 Parameter data in addition to the URL can be passed as preceding text in the
1019 string, as items of the form XXX=yyy. The URL itself can be detected because it
1020 must begin "ldapx://", where x is empty, s, or i.
1021
1022 Arguments:
1023 ldap_url the URL to be looked up, optionally preceded by other parameter
1024 settings
1025 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
1026 SEARCH_LDAP_SINGLE allows values from one entry only
1027 SEARCH_LDAP_DN gets the DN from one entry
1028 res set to point at the result
1029 errmsg set to point a message if result is not OK
1030
1031 Returns: OK or FAIL or DEFER
1032 */
1033
1034 static int
1035 control_ldap_search(uschar *ldap_url, int search_type, uschar **res,
1036 uschar **errmsg)
1037 {
1038 BOOL defer_break = FALSE;
1039 int timelimit = LDAP_NO_LIMIT;
1040 int sizelimit = LDAP_NO_LIMIT;
1041 int tcplimit = 0;
1042 int sep = 0;
1043 int dereference = LDAP_DEREF_NEVER;
1044 void* referrals = LDAP_OPT_ON;
1045 uschar *url = ldap_url;
1046 uschar *p;
1047 uschar *user = NULL;
1048 uschar *password = NULL;
1049 uschar *server, *list;
1050 uschar buffer[512];
1051
1052 while (isspace(*url)) url++;
1053
1054 /* Until the string begins "ldap", search for the other parameter settings that
1055 are recognized. They are of the form NAME=VALUE, with the value being
1056 optionally double-quoted. There must still be a space after it, however. No
1057 NAME has the value "ldap". */
1058
1059 while (strncmpic(url, US"ldap", 4) != 0)
1060 {
1061 uschar *name = url;
1062 while (*url != 0 && *url != '=') url++;
1063 if (*url == '=')
1064 {
1065 int namelen;
1066 uschar *value;
1067 namelen = ++url - name;
1068 value = string_dequote(&url);
1069 if (isspace(*url))
1070 {
1071 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1072 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1073 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1074 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1075 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1076 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1077
1078 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1079
1080 #ifdef LDAP_OPT_DEREF
1081 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1082 {
1083 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1084 else if (strcmpic(value, US"searching") == 0)
1085 dereference = LDAP_DEREF_SEARCHING;
1086 else if (strcmpic(value, US"finding") == 0)
1087 dereference = LDAP_DEREF_FINDING;
1088 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1089 }
1090 #else
1091 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1092 {
1093 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1094 "library - cannot use \"dereference\"");
1095 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1096 return DEFER;
1097 }
1098 #endif
1099
1100 #ifdef LDAP_OPT_REFERRALS
1101 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1102 {
1103 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1104 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1105 else
1106 {
1107 *errmsg = string_sprintf("LDAP option REFERRALS is not \"follow\" "
1108 "or \"nofollow\"");
1109 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1110 return DEFER;
1111 }
1112 }
1113 #else
1114 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1115 {
1116 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1117 "library - cannot use \"referrals\"");
1118 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1119 return DEFER;
1120 }
1121 #endif
1122
1123 else
1124 {
1125 *errmsg =
1126 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1127 namelen, name);
1128 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1129 return DEFER;
1130 }
1131 while (isspace(*url)) url++;
1132 continue;
1133 }
1134 }
1135 *errmsg = US"malformed parameter setting precedes LDAP URL";
1136 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1137 return DEFER;
1138 }
1139
1140 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1141 but it seems that not all behave like this. The DN for the user is often the
1142 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1143 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1144 far too complicated. */
1145
1146 if (user != NULL)
1147 {
1148 uschar *s;
1149 uschar *t = user;
1150 for (s = user; *s != 0; s++)
1151 {
1152 int c, d;
1153 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1154 {
1155 c = tolower(c);
1156 d = tolower(d);
1157 *t++ =
1158 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1159 ((d >= 'a')? (10 + d - 'a') : d - '0');
1160 s += 2;
1161 }
1162 else *t++ = *s;
1163 }
1164 *t = 0;
1165 }
1166
1167 DEBUG(D_lookup)
1168 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1169 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1170 tcplimit, dereference, (referrals == LDAP_OPT_ON)? "on" : "off");
1171
1172 /* If the request is just to check authentication, some credentials must
1173 be given. The password must not be empty because LDAP binds with an empty
1174 password are considered anonymous, and will succeed on most installations. */
1175
1176 if (search_type == SEARCH_LDAP_AUTH)
1177 {
1178 if (user == NULL || password == NULL)
1179 {
1180 *errmsg = US"ldapauth lookups must specify the username and password";
1181 return DEFER;
1182 }
1183 if (password[0] == 0)
1184 {
1185 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1186 return FAIL;
1187 }
1188 }
1189
1190 /* Check for valid ldap url starters */
1191
1192 p = url + 4;
1193 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1194 if (Ustrncmp(p, "://", 3) != 0)
1195 {
1196 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1197 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1198 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1199 return DEFER;
1200 }
1201
1202 /* No default servers, or URL contains a server name: just one attempt */
1203
1204 if (eldap_default_servers == NULL || p[3] != '/')
1205 {
1206 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1207 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1208 referrals);
1209 }
1210
1211 /* Loop through the default servers until OK or FAIL */
1212
1213 list = eldap_default_servers;
1214 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1215 {
1216 int rc;
1217 int port = 0;
1218 uschar *colon = Ustrchr(server, ':');
1219 if (colon != NULL)
1220 {
1221 *colon = 0;
1222 port = Uatoi(colon+1);
1223 }
1224 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1225 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1226 referrals);
1227 if (rc != DEFER || defer_break) return rc;
1228 }
1229
1230 return DEFER;
1231 }
1232
1233
1234
1235 /*************************************************
1236 * Find entry point *
1237 *************************************************/
1238
1239 /* See local README for interface description. The different kinds of search
1240 are handled by a common function, with a flag to differentiate between them.
1241 The handle and filename arguments are not used. */
1242
1243 static int
1244 eldap_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1245 uschar **result, uschar **errmsg, BOOL *do_cache)
1246 {
1247 /* Keep picky compilers happy */
1248 do_cache = do_cache;
1249 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1250 }
1251
1252 static int
1253 eldapm_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1254 uschar **result, uschar **errmsg, BOOL *do_cache)
1255 {
1256 /* Keep picky compilers happy */
1257 do_cache = do_cache;
1258 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1259 }
1260
1261 static int
1262 eldapdn_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1263 uschar **result, uschar **errmsg, BOOL *do_cache)
1264 {
1265 /* Keep picky compilers happy */
1266 do_cache = do_cache;
1267 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1268 }
1269
1270 int
1271 eldapauth_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1272 uschar **result, uschar **errmsg, BOOL *do_cache)
1273 {
1274 /* Keep picky compilers happy */
1275 do_cache = do_cache;
1276 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1277 }
1278
1279
1280
1281 /*************************************************
1282 * Open entry point *
1283 *************************************************/
1284
1285 /* See local README for interface description. */
1286
1287 static void *
1288 eldap_open(uschar *filename, uschar **errmsg)
1289 {
1290 return (void *)(1); /* Just return something non-null */
1291 }
1292
1293
1294
1295 /*************************************************
1296 * Tidy entry point *
1297 *************************************************/
1298
1299 /* See local README for interface description.
1300 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1301
1302 static void
1303 eldap_tidy(void)
1304 {
1305 LDAP_CONNECTION *lcp = NULL;
1306 eldap_dn = NULL;
1307
1308 while ((lcp = ldap_connections) != NULL)
1309 {
1310 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1311 lcp->port);
1312 ldap_unbind(lcp->ld);
1313 ldap_connections = lcp->next;
1314 }
1315 }
1316
1317
1318
1319 /*************************************************
1320 * Quote entry point *
1321 *************************************************/
1322
1323 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1324 quoting have to be done: LDAP quoting, and URL quoting. The current
1325 specification is the result of a suggestion by Brian Candler. It recognizes
1326 two separate cases:
1327
1328 (1) For text that appears in a search filter, the following escapes are
1329 required (see RFC 2254):
1330
1331 * -> \2A
1332 ( -> \28
1333 ) -> \29
1334 \ -> \5C
1335 NULL -> \00
1336
1337 Then the entire filter text must be URL-escaped. This kind of quoting is
1338 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1339 in the input string, because that's a terminator.
1340
1341 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1342
1343 , + " \ < > ;
1344
1345 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1346 must be escaped, as must a leading #. Then the string must be URL-quoted.
1347 This type of quoting is implemented by ${quote_ldap_dn:....}.
1348
1349 For URL quoting, the only characters that need not be quoted are the
1350 alphamerics and
1351
1352 ! $ ' ( ) * + - . _
1353
1354 All the others must be hexified and preceded by %. This includes the
1355 backslashes used for LDAP quoting.
1356
1357 For a DN that is given in the USER parameter for authentication, we need the
1358 same initial quoting as (2) but in this case, the result must NOT be
1359 URL-escaped, because it isn't a URL. The way this is handled is by
1360 de-URL-quoting the text when processing the USER parameter in
1361 control_ldap_search() above. That means that the same quote operator can be
1362 used. This has the additional advantage that spaces in the DN won't cause
1363 parsing problems. For example:
1364
1365 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1366
1367 should be safe if there are spaces in $1.
1368
1369
1370 Arguments:
1371 s the string to be quoted
1372 opt additional option text or NULL if none
1373 only "dn" is recognized
1374
1375 Returns: the processed string or NULL for a bad option
1376 */
1377
1378
1379
1380 /* The characters in this string, together with alphanumerics, never need
1381 quoting in any way. */
1382
1383 #define ALWAYS_LITERAL "!$'-._"
1384
1385 /* The special characters in this string do not need to be URL-quoted. The set
1386 is a bit larger than the general literals. */
1387
1388 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1389
1390 /* The following macros define the characters that are quoted by quote_ldap and
1391 quote_ldap_dn, respectively. */
1392
1393 #define LDAP_QUOTE "*()\\"
1394 #define LDAP_DN_QUOTE ",+\"\\<>;"
1395
1396
1397
1398 static uschar *
1399 eldap_quote(uschar *s, uschar *opt)
1400 {
1401 register int c;
1402 int count = 0;
1403 int len = 0;
1404 BOOL dn = FALSE;
1405 uschar *t = s;
1406 uschar *quoted;
1407
1408 /* Test for a DN quotation. */
1409
1410 if (opt != NULL)
1411 {
1412 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1413 dn = TRUE;
1414 }
1415
1416 /* Compute how much extra store we need for the string. This doesn't have to be
1417 exact as long as it isn't an underestimate. The worst case is the addition of 5
1418 extra bytes for a single character. This occurs for certain characters in DNs,
1419 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1420 possibly escaped character. The really fast way would be just to test for
1421 non-alphanumerics, but it is probably better to spot a few others that are
1422 never escaped, because if there are no specials at all, we can avoid copying
1423 the string. */
1424
1425 while ((c = *t++) != 0)
1426 {
1427 len++;
1428 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1429 }
1430 if (count == 0) return s;
1431
1432 /* Get sufficient store to hold the quoted string */
1433
1434 t = quoted = store_get(len + count + 1);
1435
1436 /* Handle plain quote_ldap */
1437
1438 if (!dn)
1439 {
1440 while ((c = *s++) != 0)
1441 {
1442 if (!isalnum(c))
1443 {
1444 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1445 {
1446 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1447 t += 5;
1448 continue;
1449 }
1450 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1451 {
1452 sprintf(CS t, "%%%02X", c);
1453 t += 3;
1454 continue;
1455 }
1456 }
1457 *t++ = c; /* unquoted character */
1458 }
1459 }
1460
1461 /* Handle quote_ldap_dn */
1462
1463 else
1464 {
1465 uschar *ss = s + len;
1466
1467 /* Find the last char before any trailing spaces */
1468
1469 while (ss > s && ss[-1] == ' ') ss--;
1470
1471 /* Quote leading spaces and sharps */
1472
1473 for (; s < ss; s++)
1474 {
1475 if (*s != ' ' && *s != '#') break;
1476 sprintf(CS t, "%%5C%%%02X", *s);
1477 t += 6;
1478 }
1479
1480 /* Handle the rest of the string, up to the trailing spaces */
1481
1482 while (s < ss)
1483 {
1484 c = *s++;
1485 if (!isalnum(c))
1486 {
1487 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1488 {
1489 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1490 t += 3; /* fall through to check URL */
1491 }
1492 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1493 {
1494 sprintf(CS t, "%%%02X", c);
1495 t += 3;
1496 continue;
1497 }
1498 }
1499 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1500 }
1501
1502 /* Handle the trailing spaces */
1503
1504 while (*ss++ != 0)
1505 {
1506 Ustrncpy(t, "%5C%20", 6);
1507 t += 6;
1508 }
1509 }
1510
1511 /* Terminate the new string and return */
1512
1513 *t = 0;
1514 return quoted;
1515 }
1516
1517
1518
1519 /*************************************************
1520 * Version reporting entry point *
1521 *************************************************/
1522
1523 /* See local README for interface description. */
1524
1525 #include "../version.h"
1526
1527 void
1528 ldap_version_report(FILE *f)
1529 {
1530 #ifdef DYNLOOKUP
1531 fprintf(f, "Library version: LDAP: Exim version %s\n", EXIM_VERSION_STR);
1532 #endif
1533 }
1534
1535
1536 static lookup_info ldap_lookup_info = {
1537 US"ldap", /* lookup name */
1538 lookup_querystyle, /* query-style lookup */
1539 eldap_open, /* open function */
1540 NULL, /* check function */
1541 eldap_find, /* find function */
1542 NULL, /* no close function */
1543 eldap_tidy, /* tidy function */
1544 eldap_quote, /* quoting function */
1545 ldap_version_report /* version reporting */
1546 };
1547
1548 static lookup_info ldapdn_lookup_info = {
1549 US"ldapdn", /* lookup name */
1550 lookup_querystyle, /* query-style lookup */
1551 eldap_open, /* sic */ /* open function */
1552 NULL, /* check function */
1553 eldapdn_find, /* find function */
1554 NULL, /* no close function */
1555 eldap_tidy, /* sic */ /* tidy function */
1556 eldap_quote, /* sic */ /* quoting function */
1557 NULL /* no version reporting (redundant) */
1558 };
1559
1560 static lookup_info ldapm_lookup_info = {
1561 US"ldapm", /* lookup name */
1562 lookup_querystyle, /* query-style lookup */
1563 eldap_open, /* sic */ /* open function */
1564 NULL, /* check function */
1565 eldapm_find, /* find function */
1566 NULL, /* no close function */
1567 eldap_tidy, /* sic */ /* tidy function */
1568 eldap_quote, /* sic */ /* quoting function */
1569 NULL /* no version reporting (redundant) */
1570 };
1571
1572 #ifdef DYNLOOKUP
1573 #define ldap_lookup_module_info _lookup_module_info
1574 #endif
1575
1576 static lookup_info *_lookup_list[] = { &ldap_lookup_info, &ldapdn_lookup_info, &ldapm_lookup_info };
1577 lookup_module_info ldap_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
1578
1579 /* End of lookups/ldap.c */