cfd384ccb3a05b841639b3d0d80ff53dea978b8e
[exim.git] / src / src / lookups / ldap.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2015 */
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(const uschar *ldap_url, uschar *server, int s_port,
134 int search_type, uschar **res, uschar **errmsg, BOOL *defer_break,
135 uschar *user, uschar *password, int sizelimit, int timelimit, int tcplimit,
136 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 attrs_requested = 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 attrs_requested++;
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 #ifdef LDAP_OPT_X_TLS_NEWCTX
285 int am_server = 0;
286 LDAP *ldsetctx;
287 #else
288 LDAP *ldsetctx = NULL;
289 #endif
290
291
292 /* --------------------------- OpenLDAP ------------------------ */
293
294 /* There seems to be a preference under OpenLDAP for ldap_initialize()
295 instead of ldap_init(), though I have as yet been unable to find
296 documentation that says this. (OpenLDAP documentation is sparse to
297 non-existent). So we handle OpenLDAP differently here. Also, support for
298 ldapi seems to be OpenLDAP-only at present. */
299
300 #ifdef LDAP_LIB_OPENLDAP2
301
302 /* We now need an empty string for the default host. Get some store in which
303 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
304 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
305 than the host name + "ldaps:///" plus : and a port number, say 20 + the
306 length of the host name. What we get should accommodate both, easily. */
307
308 uschar *shost = (host == NULL)? US"" : host;
309 uschar *init_url = store_get(20 + 3 * Ustrlen(shost));
310 uschar *init_ptr;
311
312 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
313 contain the path name, with slashes escaped as %2F. */
314
315 if (ldapi)
316 {
317 int ch;
318 init_ptr = init_url + 8;
319 Ustrcpy(init_url, "ldapi://");
320 while ((ch = *shost++) != 0)
321 {
322 if (ch == '/')
323 {
324 Ustrncpy(init_ptr, "%2F", 3);
325 init_ptr += 3;
326 }
327 else *init_ptr++ = ch;
328 }
329 *init_ptr = 0;
330 }
331
332 /* This is not an ldapi call. Just build a URI with the protocol type, host
333 name, and port. */
334
335 else
336 {
337 init_ptr = Ustrchr(ldap_url, '/');
338 Ustrncpy(init_url, ldap_url, init_ptr - ldap_url);
339 init_ptr = init_url + (init_ptr - ldap_url);
340 sprintf(CS init_ptr, "//%s:%d/", shost, port);
341 }
342
343 /* Call ldap_initialize() and check the result */
344
345 DEBUG(D_lookup) debug_printf("ldap_initialize with URL %s\n", init_url);
346 rc = ldap_initialize(&ld, CS init_url);
347 if (rc != LDAP_SUCCESS)
348 {
349 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
350 rc, init_url);
351 goto RETURN_ERROR;
352 }
353 store_reset(init_url); /* Might as well save memory when we can */
354
355
356 /* ------------------------- Not OpenLDAP ---------------------- */
357
358 /* For libraries other than OpenLDAP, use ldap_init(). */
359
360 #else /* LDAP_LIB_OPENLDAP2 */
361 ld = ldap_init(CS host, port);
362 #endif /* LDAP_LIB_OPENLDAP2 */
363
364 /* -------------------------------------------------------------- */
365
366
367 /* Handle failure to initialize */
368
369 if (ld == NULL)
370 {
371 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
372 host, porttext, strerror(errno));
373 goto RETURN_ERROR;
374 }
375
376 #ifdef LDAP_OPT_X_TLS_NEWCTX
377 ldsetctx = ld;
378 #endif
379
380 /* Set the TCP connect time limit if available. This is something that is
381 in Netscape SDK v4.1; I don't know about other libraries. */
382
383 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
384 if (tcplimit > 0)
385 {
386 int timeout1000 = tcplimit*1000;
387 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
388 }
389 else
390 {
391 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
392 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&notimeout);
393 }
394 #endif
395
396 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
397
398 #ifdef LDAP_OPT_NETWORK_TIMEOUT
399 if (tcplimit > 0)
400 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
401 #endif
402
403 /* I could not get TLS to work until I set the version to 3. That version
404 seems to be the default nowadays. The RFC is dated 1997, so I would hope
405 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
406 been set, go for v3 if we can. */
407
408 if (eldap_version < 0)
409 {
410 #ifdef LDAP_VERSION3
411 eldap_version = LDAP_VERSION3;
412 #else
413 eldap_version = 2;
414 #endif
415 }
416
417 #ifdef LDAP_OPT_PROTOCOL_VERSION
418 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
419 #endif
420
421 DEBUG(D_lookup) debug_printf("initialized for LDAP (v%d) server %s%s\n",
422 eldap_version, host, porttext);
423
424 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
425 for "ldaps" and soft otherwise. */
426
427 #ifdef LDAP_OPT_X_TLS
428 if (!ldapi)
429 {
430 int tls_option;
431 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
432 if (eldap_require_cert != NULL)
433 {
434 tls_option = LDAP_OPT_X_TLS_NEVER;
435 if (Ustrcmp(eldap_require_cert, "hard") == 0)
436 {
437 tls_option = LDAP_OPT_X_TLS_HARD;
438 }
439 else if (Ustrcmp(eldap_require_cert, "demand") == 0)
440 {
441 tls_option = LDAP_OPT_X_TLS_DEMAND;
442 }
443 else if (Ustrcmp(eldap_require_cert, "allow") == 0)
444 {
445 tls_option = LDAP_OPT_X_TLS_ALLOW;
446 }
447 else if (Ustrcmp(eldap_require_cert, "try") == 0)
448 {
449 tls_option = LDAP_OPT_X_TLS_TRY;
450 }
451 DEBUG(D_lookup)
452 debug_printf("Require certificate overrides LDAP_OPT_X_TLS option (%d)\n",
453 tls_option);
454 }
455 else
456 #endif /* LDAP_OPT_X_TLS_REQUIRE_CERT */
457 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
458 {
459 tls_option = LDAP_OPT_X_TLS_HARD;
460 DEBUG(D_lookup)
461 debug_printf("LDAP_OPT_X_TLS_HARD set due to ldaps:// URI\n");
462 }
463 else
464 {
465 tls_option = LDAP_OPT_X_TLS_TRY;
466 DEBUG(D_lookup)
467 debug_printf("LDAP_OPT_X_TLS_TRY set due to ldap:// URI\n");
468 }
469 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
470 }
471 #endif /* LDAP_OPT_X_TLS */
472
473 #ifdef LDAP_OPT_X_TLS_CACERTFILE
474 if (eldap_ca_cert_file != NULL)
475 {
476 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CACERTFILE, eldap_ca_cert_file);
477 }
478 #endif
479 #ifdef LDAP_OPT_X_TLS_CACERTDIR
480 if (eldap_ca_cert_dir != NULL)
481 {
482 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CACERTDIR, eldap_ca_cert_dir);
483 }
484 #endif
485 #ifdef LDAP_OPT_X_TLS_CERTFILE
486 if (eldap_cert_file != NULL)
487 {
488 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CERTFILE, eldap_cert_file);
489 }
490 #endif
491 #ifdef LDAP_OPT_X_TLS_KEYFILE
492 if (eldap_cert_key != NULL)
493 {
494 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_KEYFILE, eldap_cert_key);
495 }
496 #endif
497 #ifdef LDAP_OPT_X_TLS_CIPHER_SUITE
498 if (eldap_cipher_suite != NULL)
499 {
500 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CIPHER_SUITE, eldap_cipher_suite);
501 }
502 #endif
503 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
504 if (eldap_require_cert != NULL)
505 {
506 int cert_option = LDAP_OPT_X_TLS_NEVER;
507 if (Ustrcmp(eldap_require_cert, "hard") == 0)
508 {
509 cert_option = LDAP_OPT_X_TLS_HARD;
510 }
511 else if (Ustrcmp(eldap_require_cert, "demand") == 0)
512 {
513 cert_option = LDAP_OPT_X_TLS_DEMAND;
514 }
515 else if (Ustrcmp(eldap_require_cert, "allow") == 0)
516 {
517 cert_option = LDAP_OPT_X_TLS_ALLOW;
518 }
519 else if (Ustrcmp(eldap_require_cert, "try") == 0)
520 {
521 cert_option = LDAP_OPT_X_TLS_TRY;
522 }
523 /* This ldap handle is set at compile time based on client libs. Older
524 * versions want it to be global and newer versions can force a reload
525 * of the TLS context (to reload these settings we are changing from the
526 * default that loaded at instantiation). */
527 rc = ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_REQUIRE_CERT, &cert_option);
528 if (rc)
529 {
530 DEBUG(D_lookup)
531 debug_printf("Unable to set TLS require cert_option(%d) globally: %s\n",
532 cert_option, ldap_err2string(rc));
533 }
534 }
535 #endif
536 #ifdef LDAP_OPT_X_TLS_NEWCTX
537 rc = ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_NEWCTX, &am_server);
538 if (rc)
539 {
540 DEBUG(D_lookup)
541 debug_printf("Unable to reload TLS context %d: %s\n",
542 rc, ldap_err2string(rc));
543 }
544 #endif
545
546 /* Now add this connection to the chain of cached connections */
547
548 lcp = store_get(sizeof(LDAP_CONNECTION));
549 lcp->host = (host == NULL)? NULL : string_copy(host);
550 lcp->bound = FALSE;
551 lcp->user = NULL;
552 lcp->password = NULL;
553 lcp->port = port;
554 lcp->ld = ld;
555 lcp->next = ldap_connections;
556 lcp->is_start_tls_called = FALSE;
557 ldap_connections = lcp;
558 }
559
560 /* Found cached connection */
561
562 else
563 {
564 DEBUG(D_lookup)
565 debug_printf("re-using cached connection to LDAP server %s%s\n",
566 host, porttext);
567 }
568
569 /* Bind with the user/password supplied, or an anonymous bind if these values
570 are NULL, unless a cached connection is already bound with the same values. */
571
572 if (!lcp->bound ||
573 (lcp->user == NULL && user != NULL) ||
574 (lcp->user != NULL && user == NULL) ||
575 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
576 (lcp->password == NULL && password != NULL) ||
577 (lcp->password != NULL && password == NULL) ||
578 (lcp->password != NULL && password != NULL &&
579 Ustrcmp(lcp->password, password) != 0))
580 {
581 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
582 (lcp->bound)? "re-" : "", user, password);
583 if (eldap_start_tls && !lcp->is_start_tls_called)
584 {
585 #if defined(LDAP_OPT_X_TLS) && !defined(LDAP_LIB_SOLARIS)
586 /* The Oracle LDAP libraries (LDAP_LIB_TYPE=SOLARIS) don't support this.
587 * Note: moreover, they appear to now define LDAP_OPT_X_TLS and still not
588 * export an ldap_start_tls_s symbol.
589 */
590 if ( (rc = ldap_start_tls_s(lcp->ld, NULL, NULL)) != LDAP_SUCCESS)
591 {
592 *errmsg = string_sprintf("failed to initiate TLS processing on an "
593 "LDAP session to server %s%s - ldap_start_tls_s() returned %d:"
594 " %s", host, porttext, rc, ldap_err2string(rc));
595 goto RETURN_ERROR;
596 }
597 lcp->is_start_tls_called = TRUE;
598 #else
599 DEBUG(D_lookup)
600 debug_printf("TLS initiation not supported with this Exim and your LDAP library.\n");
601 #endif
602 }
603 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
604 == -1)
605 {
606 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
607 "%s%s - ldap_bind() returned -1", host, porttext);
608 goto RETURN_ERROR;
609 }
610
611 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
612 {
613 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
614 "%s%s - LDAP error: %s", host, porttext,
615 rc == -1 ? "result retrieval failed" : "timeout" );
616 result = NULL;
617 goto RETURN_ERROR;
618 }
619
620 rc = ldap_result2error( lcp->ld, result, 0 );
621
622 /* Invalid credentials when just checking credentials returns FAIL. This
623 stops any further servers being tried. */
624
625 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
626 {
627 DEBUG(D_lookup)
628 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
629 error_yield = FAIL;
630 goto RETURN_ERROR_NOMSG;
631 }
632
633 /* Otherwise we have a problem that doesn't stop further servers from being
634 tried. */
635
636 if (rc != LDAP_SUCCESS)
637 {
638 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
639 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
640 goto RETURN_ERROR;
641 }
642
643 /* Successful bind */
644
645 lcp->bound = TRUE;
646 lcp->user = (user == NULL)? NULL : string_copy(user);
647 lcp->password = (password == NULL)? NULL : string_copy(password);
648
649 ldap_msgfree(result);
650 result = NULL;
651 }
652
653 /* If we are just checking credentials, return OK. */
654
655 if (search_type == SEARCH_LDAP_AUTH)
656 {
657 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
658 goto RETURN_OK;
659 }
660
661 /* Before doing the search, set the time and size limits (if given). Here again
662 the different implementations of LDAP have chosen to do things differently. */
663
664 #if defined(LDAP_OPT_SIZELIMIT)
665 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
666 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
667 #else
668 lcp->ld->ld_sizelimit = sizelimit;
669 lcp->ld->ld_timelimit = timelimit;
670 #endif
671
672 /* Similarly for dereferencing aliases. Don't know if this is possible on
673 an LDAP library without LDAP_OPT_DEREF. */
674
675 #if defined(LDAP_OPT_DEREF)
676 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
677 #endif
678
679 /* Similarly for the referral setting; should the library follow referrals that
680 the LDAP server returns? The conditional is just in case someone uses a library
681 without it. */
682
683 #if defined(LDAP_OPT_REFERRALS)
684 ldap_set_option(lcp->ld, LDAP_OPT_REFERRALS, referrals);
685 #endif
686
687 /* Start the search on the server. */
688
689 DEBUG(D_lookup) debug_printf("Start search\n");
690
691 msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
692 ludp->lud_attrs, 0);
693
694 if (msgid == -1)
695 {
696 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
697 int err;
698 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
699 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
700 ldap_err2string(err));
701
702 #else
703 *errmsg = string_sprintf("ldap_search failed");
704 #endif
705
706 goto RETURN_ERROR;
707 }
708
709 /* Loop to pick up results as they come in, setting a timeout if one was
710 given. */
711
712 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
713 LDAP_RES_SEARCH_ENTRY)
714 {
715 LDAPMessage *e;
716
717 DEBUG(D_lookup) debug_printf("LDAP result loop\n");
718
719 for(e = ldap_first_entry(lcp->ld, result);
720 e != NULL;
721 e = ldap_next_entry(lcp->ld, e))
722 {
723 uschar *new_dn;
724 BOOL insert_space = FALSE;
725
726 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
727
728 rescount++; /* Count results */
729
730 /* Results for multiple entries values are separated by newlines. */
731
732 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
733
734 /* Get the DN from the last result. */
735
736 new_dn = US ldap_get_dn(lcp->ld, e);
737 if (new_dn != NULL)
738 {
739 if (dn != NULL)
740 {
741 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
742 ldap_memfree(dn);
743 #else /* OPENLDAP 1, UMich, Solaris */
744 free(dn);
745 #endif
746 }
747 /* Save for later */
748 dn = new_dn;
749 }
750
751 /* If the data we want is actually the DN rather than any attribute values,
752 (an "ldapdn" search) add it to the data string. If there are multiple
753 entries, the DNs will be concatenated, but we test for this case below, as
754 for SEARCH_LDAP_SINGLE, and give an error. */
755
756 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
757 { /* condition, because of the else */
758 if (new_dn != NULL) /* below, that's for the first only */
759 {
760 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
761 data[ptr] = 0;
762 attribute_found = TRUE;
763 }
764 }
765
766 /* Otherwise, loop through the entry, grabbing attribute values. If there's
767 only one attribute being retrieved, no attribute name is given, and the
768 result is not quoted. Multiple values are separated by (comma).
769 If more than one attribute is being retrieved, the data is given as a
770 sequence of name=value pairs, separated by (space), with the value always in quotes.
771 If there are multiple values, they are given within the quotes, comma separated. */
772
773 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
774 attr != NULL;
775 attr = US ldap_next_attribute(lcp->ld, e, ber))
776 {
777 DEBUG(D_lookup) debug_printf("LDAP attr loop\n");
778 if (attr[0] != 0)
779 {
780 /* Get array of values for this attribute. */
781
782 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
783 != NULL)
784 {
785
786 if (attrs_requested != 1)
787 {
788 if (insert_space)
789 data = string_cat(data, &size, &ptr, US" ", 1);
790 else
791 insert_space = TRUE;
792 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
793 data = string_cat(data, &size, &ptr, US"=\"", 2);
794 }
795
796 while (*values != NULL)
797 {
798 uschar *value = *values;
799 int len = Ustrlen(value);
800
801 DEBUG(D_lookup) debug_printf("LDAP value loop %s:%s\n", attr, value);
802
803 /* In case we requested one attribute only but got several times
804 into that attr loop, we need to append the additional values.
805 (This may happen if you derive attributeTypes B and C from A and
806 then query for A.) In all other cases we detect the different
807 attribute and append only every non first value. */
808
809 if ((attr_count == 1 && data) || (values != firstval))
810 data = string_cat(data, &size, &ptr, US",", 1);
811
812 /* For multiple attributes, the data is in quotes. We must escape
813 internal quotes, backslashes, newlines, and must double commas. */
814
815 if (attrs_requested != 1)
816 {
817 int j;
818 for (j = 0; j < len; j++)
819 {
820 if (value[j] == '\n')
821 data = string_cat(data, &size, &ptr, US"\\n", 2);
822 else if (value[j] == ',')
823 data = string_cat(data, &size, &ptr, US",,", 2);
824 else
825 {
826 if (value[j] == '\"' || value[j] == '\\')
827 data = string_cat(data, &size, &ptr, US"\\", 1);
828 data = string_cat(data, &size, &ptr, value+j, 1);
829 }
830 }
831 }
832
833 /* For single attributes, just double commas */
834
835 else
836 {
837 int j;
838 for (j = 0; j < len; j++)
839 {
840 if (value[j] == ',')
841 data = string_cat(data, &size, &ptr, US",,", 2);
842 else
843 data = string_cat(data, &size, &ptr, value+j, 1);
844 }
845 }
846
847
848 /* Move on to the next value */
849
850 values++;
851 attribute_found = TRUE;
852 }
853
854 /* Closing quote at the end of the data for a named attribute. */
855
856 if (attrs_requested != 1)
857 data = string_cat(data, &size, &ptr, US"\"", 1);
858
859 /* Free the values */
860
861 ldap_value_free(CSS firstval);
862 }
863 }
864
865 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
866
867 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
868 to be freed. UMich LDAP stores them in static storage and does not require
869 this. */
870
871 ldap_memfree(attr);
872 #endif
873 } /* End "for" loop for extracting attributes from an entry */
874 } /* End "for" loop for extracting entries from a result */
875
876 /* Free the result */
877
878 ldap_msgfree(result);
879 result = NULL;
880 } /* End "while" loop for multiple results */
881
882 /* Terminate the dynamic string that we have built and reclaim unused store */
883
884 if (data != NULL)
885 {
886 data[ptr] = 0;
887 store_reset(data + ptr + 1);
888 }
889
890 /* Copy the last dn into eldap_dn */
891
892 if (dn != NULL)
893 {
894 eldap_dn = string_copy(dn);
895 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
896 ldap_memfree(dn);
897 #else /* OPENLDAP 1, UMich, Solaris */
898 free(dn);
899 #endif
900 }
901
902 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
903
904 if (rc == 0)
905 {
906 *errmsg = US"ldap_result timed out";
907 goto RETURN_ERROR;
908 }
909
910 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
911 provide you with a message". Other error states seem to exist where
912 ldap_result() didn't give us any message from the server at all, leaving result
913 set to NULL. Apparently, "the error parameters of the LDAP session handle will
914 be set accordingly". That's the best we can do to retrieve an error status; we
915 can't use functions like ldap_result2error because they parse a message from
916 the server, which we didn't get.
917
918 Annoyingly, the different implementations of LDAP have gone for different
919 methods of handling error codes and generating error messages. */
920
921 if (rc == -1 || result == NULL)
922 {
923 int err;
924 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
925
926 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
927 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
928 *errmsg = string_sprintf("ldap_result failed: %d, %s",
929 err, ldap_err2string(err));
930
931 #elif defined LDAP_LIB_NETSCAPE
932 /* Dubious (surely 'matched' is spurious here?) */
933 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
934 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
935
936 #else /* UMich LDAP aka OpenLDAP 1.x */
937 *errmsg = string_sprintf("ldap_result failed: %d, %s",
938 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
939 #endif
940
941 goto RETURN_ERROR;
942 }
943
944 /* A return code that isn't -1 doesn't necessarily mean there were no problems
945 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
946 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
947 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
948 we don't provide that functionality when we can't. :-) */
949
950 if (rc != LDAP_RES_SEARCH_RESULT
951 #ifdef LDAP_RES_SEARCH_REFERENCE
952 && rc != LDAP_RES_SEARCH_REFERENCE
953 #endif
954 )
955 {
956 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
957 goto RETURN_ERROR;
958 }
959
960 /* We have a result message from the server. This doesn't yet mean all is well.
961 We need to parse the message to find out exactly what's happened. */
962
963 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
964 ldap_rc = rc;
965 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
966 CSS &error2, NULL, NULL, 0);
967 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
968 if (ldap_parse_rc < 0 &&
969 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
970 #ifdef LDAP_RES_SEARCH_REFERENCE
971 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
972 #endif
973 ))
974 {
975 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
976 goto RETURN_ERROR;
977 }
978 error1 = US ldap_err2string(rc);
979
980 #elif defined LDAP_LIB_NETSCAPE
981 /* Dubious (it doesn't reference 'result' at all!) */
982 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
983
984 #else /* UMich LDAP aka OpenLDAP 1.x */
985 rc = ldap_result2error(lcp->ld, result, 0);
986 error1 = ldap_err2string(rc);
987 error2 = lcp->ld->ld_error;
988 matched = lcp->ld->ld_matched;
989 #endif
990
991 /* Process the status as follows:
992
993 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
994 truncated result list.
995
996 (2) If we get LDAP_RES_SEARCH_REFERENCE, also just carry on. This was a
997 submitted patch that is reported to "do the right thing" with Solaris
998 LDAP libraries. (The problem it addresses apparently does not occur with
999 Open LDAP.)
1000
1001 (3) The range of errors defined by LDAP_NAME_ERROR generally mean "that
1002 object does not, or cannot, exist in the database". For those cases we
1003 fail the lookup.
1004
1005 (4) All other non-successes here are treated as some kind of problem with
1006 the lookup, so return DEFER (which is the default in error_yield).
1007 */
1008
1009 DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
1010 rc, ldap_err2string(rc));
1011
1012 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED
1013 #ifdef LDAP_RES_SEARCH_REFERENCE
1014 && rc != LDAP_RES_SEARCH_REFERENCE
1015 #endif
1016 )
1017 {
1018 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
1019 rc,
1020 (error1 != NULL)? error1 : US"",
1021 (error2 != NULL && error2[0] != 0)? US"/" : US"",
1022 (error2 != NULL)? error2 : US"",
1023 (matched != NULL && matched[0] != 0)? US"/" : US"",
1024 (matched != NULL)? matched : US"");
1025
1026 #if defined LDAP_NAME_ERROR
1027 if (LDAP_NAME_ERROR(rc))
1028 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
1029 if (NAME_ERROR(rc))
1030 #else
1031 if (rc == LDAP_NO_SUCH_OBJECT)
1032 #endif
1033
1034 {
1035 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
1036 error_yield = FAIL;
1037 }
1038 goto RETURN_ERROR;
1039 }
1040
1041 /* The search succeeded. Check if we have too many results */
1042
1043 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
1044 {
1045 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
1046 "(filter not specific enough?)", rescount);
1047 goto RETURN_ERROR_BREAK;
1048 }
1049
1050 /* Check if we have too few (zero) entries */
1051
1052 if (rescount < 1)
1053 {
1054 *errmsg = string_sprintf("LDAP search: no results");
1055 error_yield = FAIL;
1056 goto RETURN_ERROR_BREAK;
1057 }
1058
1059 /* If an entry was found, but it had no attributes, we behave as if no entries
1060 were found, that is, the lookup failed. */
1061
1062 if (!attribute_found)
1063 {
1064 *errmsg = US"LDAP search: found no attributes";
1065 error_yield = FAIL;
1066 goto RETURN_ERROR;
1067 }
1068
1069 /* Otherwise, it's all worked */
1070
1071 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
1072 *res = data;
1073
1074 RETURN_OK:
1075 if (result != NULL) ldap_msgfree(result);
1076 ldap_free_urldesc(ludp);
1077 return OK;
1078
1079 /* Error returns */
1080
1081 RETURN_ERROR_BREAK:
1082 *defer_break = TRUE;
1083
1084 RETURN_ERROR:
1085 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1086
1087 RETURN_ERROR_NOMSG:
1088 if (result != NULL) ldap_msgfree(result);
1089 if (ludp != NULL) ldap_free_urldesc(ludp);
1090
1091 #if defined LDAP_LIB_OPENLDAP2
1092 if (error2 != NULL) ldap_memfree(error2);
1093 if (matched != NULL) ldap_memfree(matched);
1094 #endif
1095
1096 return error_yield;
1097 }
1098
1099
1100
1101 /*************************************************
1102 * Internal search control function *
1103 *************************************************/
1104
1105 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
1106 and eldapm_find() with a difference in the "search_type" argument. It controls
1107 calls to perform_ldap_search() which actually does the work. We call that
1108 repeatedly for certain types of defer in the case when the URL contains no host
1109 name and eldap_default_servers is set to a list of servers to try. This gives
1110 more control than just passing over a list of hosts to ldap_open() because it
1111 handles other kinds of defer as well as just a failure to open. Note that the
1112 URL is defined to contain either zero or one "hostport" only.
1113
1114 Parameter data in addition to the URL can be passed as preceding text in the
1115 string, as items of the form XXX=yyy. The URL itself can be detected because it
1116 must begin "ldapx://", where x is empty, s, or i.
1117
1118 Arguments:
1119 ldap_url the URL to be looked up, optionally preceded by other parameter
1120 settings
1121 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
1122 SEARCH_LDAP_SINGLE allows values from one entry only
1123 SEARCH_LDAP_DN gets the DN from one entry
1124 res set to point at the result
1125 errmsg set to point a message if result is not OK
1126
1127 Returns: OK or FAIL or DEFER
1128 */
1129
1130 static int
1131 control_ldap_search(const uschar *ldap_url, int search_type, uschar **res,
1132 uschar **errmsg)
1133 {
1134 BOOL defer_break = FALSE;
1135 int timelimit = LDAP_NO_LIMIT;
1136 int sizelimit = LDAP_NO_LIMIT;
1137 int tcplimit = 0;
1138 int sep = 0;
1139 int dereference = LDAP_DEREF_NEVER;
1140 void* referrals = LDAP_OPT_ON;
1141 const uschar *url = ldap_url;
1142 const uschar *p;
1143 uschar *user = NULL;
1144 uschar *password = NULL;
1145 uschar *local_servers = NULL;
1146 uschar *server;
1147 const uschar *list;
1148 uschar buffer[512];
1149
1150 while (isspace(*url)) url++;
1151
1152 /* Until the string begins "ldap", search for the other parameter settings that
1153 are recognized. They are of the form NAME=VALUE, with the value being
1154 optionally double-quoted. There must still be a space after it, however. No
1155 NAME has the value "ldap". */
1156
1157 while (strncmpic(url, US"ldap", 4) != 0)
1158 {
1159 const uschar *name = url;
1160 while (*url != 0 && *url != '=') url++;
1161 if (*url == '=')
1162 {
1163 int namelen;
1164 uschar *value;
1165 namelen = ++url - name;
1166 value = string_dequote(&url);
1167 if (isspace(*url))
1168 {
1169 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1170 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1171 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1172 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1173 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1174 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1175 else if (strncmpic(name, US"SERVERS=", namelen) == 0) local_servers = value;
1176
1177 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1178
1179 #ifdef LDAP_OPT_DEREF
1180 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1181 {
1182 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1183 else if (strcmpic(value, US"searching") == 0)
1184 dereference = LDAP_DEREF_SEARCHING;
1185 else if (strcmpic(value, US"finding") == 0)
1186 dereference = LDAP_DEREF_FINDING;
1187 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1188 }
1189 #else
1190 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1191 {
1192 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1193 "library - cannot use \"dereference\"");
1194 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1195 return DEFER;
1196 }
1197 #endif
1198
1199 #ifdef LDAP_OPT_REFERRALS
1200 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1201 {
1202 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1203 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1204 else
1205 {
1206 *errmsg = string_sprintf("LDAP option REFERRALS is not \"follow\" "
1207 "or \"nofollow\"");
1208 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1209 return DEFER;
1210 }
1211 }
1212 #else
1213 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1214 {
1215 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1216 "library - cannot use \"referrals\"");
1217 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1218 return DEFER;
1219 }
1220 #endif
1221
1222 else
1223 {
1224 *errmsg =
1225 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1226 namelen, name);
1227 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1228 return DEFER;
1229 }
1230 while (isspace(*url)) url++;
1231 continue;
1232 }
1233 }
1234 *errmsg = US"malformed parameter setting precedes LDAP URL";
1235 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1236 return DEFER;
1237 }
1238
1239 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1240 but it seems that not all behave like this. The DN for the user is often the
1241 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1242 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1243 far too complicated. */
1244
1245 if (user != NULL)
1246 {
1247 uschar *s;
1248 uschar *t = user;
1249 for (s = user; *s != 0; s++)
1250 {
1251 int c, d;
1252 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1253 {
1254 c = tolower(c);
1255 d = tolower(d);
1256 *t++ =
1257 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1258 ((d >= 'a')? (10 + d - 'a') : d - '0');
1259 s += 2;
1260 }
1261 else *t++ = *s;
1262 }
1263 *t = 0;
1264 }
1265
1266 DEBUG(D_lookup)
1267 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1268 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1269 tcplimit, dereference, (referrals == LDAP_OPT_ON)? "on" : "off");
1270
1271 /* If the request is just to check authentication, some credentials must
1272 be given. The password must not be empty because LDAP binds with an empty
1273 password are considered anonymous, and will succeed on most installations. */
1274
1275 if (search_type == SEARCH_LDAP_AUTH)
1276 {
1277 if (user == NULL || password == NULL)
1278 {
1279 *errmsg = US"ldapauth lookups must specify the username and password";
1280 return DEFER;
1281 }
1282 if (password[0] == 0)
1283 {
1284 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1285 return FAIL;
1286 }
1287 }
1288
1289 /* Check for valid ldap url starters */
1290
1291 p = url + 4;
1292 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1293 if (Ustrncmp(p, "://", 3) != 0)
1294 {
1295 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1296 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1297 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1298 return DEFER;
1299 }
1300
1301 /* No default servers, or URL contains a server name: just one attempt */
1302
1303 if ((eldap_default_servers == NULL && local_servers == NULL) || p[3] != '/')
1304 {
1305 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1306 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1307 referrals);
1308 }
1309
1310 /* Loop through the default servers until OK or FAIL. Use local_servers list
1311 * if defined in the lookup, otherwise use the global default list */
1312 list = (local_servers == NULL) ? eldap_default_servers : local_servers;
1313 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1314 {
1315 int rc;
1316 int port = 0;
1317 uschar *colon = Ustrchr(server, ':');
1318 if (colon != NULL)
1319 {
1320 *colon = 0;
1321 port = Uatoi(colon+1);
1322 }
1323 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1324 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1325 referrals);
1326 if (rc != DEFER || defer_break) return rc;
1327 }
1328
1329 return DEFER;
1330 }
1331
1332
1333
1334 /*************************************************
1335 * Find entry point *
1336 *************************************************/
1337
1338 /* See local README for interface description. The different kinds of search
1339 are handled by a common function, with a flag to differentiate between them.
1340 The handle and filename arguments are not used. */
1341
1342 static int
1343 eldap_find(void *handle, uschar *filename, const uschar *ldap_url, int length,
1344 uschar **result, uschar **errmsg, uint *do_cache)
1345 {
1346 /* Keep picky compilers happy */
1347 do_cache = do_cache;
1348 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1349 }
1350
1351 static int
1352 eldapm_find(void *handle, uschar *filename, const uschar *ldap_url, int length,
1353 uschar **result, uschar **errmsg, uint *do_cache)
1354 {
1355 /* Keep picky compilers happy */
1356 do_cache = do_cache;
1357 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1358 }
1359
1360 static int
1361 eldapdn_find(void *handle, uschar *filename, const uschar *ldap_url, int length,
1362 uschar **result, uschar **errmsg, uint *do_cache)
1363 {
1364 /* Keep picky compilers happy */
1365 do_cache = do_cache;
1366 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1367 }
1368
1369 int
1370 eldapauth_find(void *handle, uschar *filename, const uschar *ldap_url, int length,
1371 uschar **result, uschar **errmsg, uint *do_cache)
1372 {
1373 /* Keep picky compilers happy */
1374 do_cache = do_cache;
1375 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1376 }
1377
1378
1379
1380 /*************************************************
1381 * Open entry point *
1382 *************************************************/
1383
1384 /* See local README for interface description. */
1385
1386 static void *
1387 eldap_open(uschar *filename, uschar **errmsg)
1388 {
1389 return (void *)(1); /* Just return something non-null */
1390 }
1391
1392
1393
1394 /*************************************************
1395 * Tidy entry point *
1396 *************************************************/
1397
1398 /* See local README for interface description.
1399 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1400
1401 static void
1402 eldap_tidy(void)
1403 {
1404 LDAP_CONNECTION *lcp = NULL;
1405 eldap_dn = NULL;
1406
1407 while ((lcp = ldap_connections) != NULL)
1408 {
1409 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1410 lcp->port);
1411 if(lcp->bound == TRUE)
1412 ldap_unbind(lcp->ld);
1413 ldap_connections = lcp->next;
1414 }
1415 }
1416
1417
1418
1419 /*************************************************
1420 * Quote entry point *
1421 *************************************************/
1422
1423 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1424 quoting have to be done: LDAP quoting, and URL quoting. The current
1425 specification is the result of a suggestion by Brian Candler. It recognizes
1426 two separate cases:
1427
1428 (1) For text that appears in a search filter, the following escapes are
1429 required (see RFC 2254):
1430
1431 * -> \2A
1432 ( -> \28
1433 ) -> \29
1434 \ -> \5C
1435 NULL -> \00
1436
1437 Then the entire filter text must be URL-escaped. This kind of quoting is
1438 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1439 in the input string, because that's a terminator.
1440
1441 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1442
1443 , + " \ < > ;
1444
1445 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1446 must be escaped, as must a leading #. Then the string must be URL-quoted.
1447 This type of quoting is implemented by ${quote_ldap_dn:....}.
1448
1449 For URL quoting, the only characters that need not be quoted are the
1450 alphamerics and
1451
1452 ! $ ' ( ) * + - . _
1453
1454 All the others must be hexified and preceded by %. This includes the
1455 backslashes used for LDAP quoting.
1456
1457 For a DN that is given in the USER parameter for authentication, we need the
1458 same initial quoting as (2) but in this case, the result must NOT be
1459 URL-escaped, because it isn't a URL. The way this is handled is by
1460 de-URL-quoting the text when processing the USER parameter in
1461 control_ldap_search() above. That means that the same quote operator can be
1462 used. This has the additional advantage that spaces in the DN won't cause
1463 parsing problems. For example:
1464
1465 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1466
1467 should be safe if there are spaces in $1.
1468
1469
1470 Arguments:
1471 s the string to be quoted
1472 opt additional option text or NULL if none
1473 only "dn" is recognized
1474
1475 Returns: the processed string or NULL for a bad option
1476 */
1477
1478
1479
1480 /* The characters in this string, together with alphanumerics, never need
1481 quoting in any way. */
1482
1483 #define ALWAYS_LITERAL "!$'-._"
1484
1485 /* The special characters in this string do not need to be URL-quoted. The set
1486 is a bit larger than the general literals. */
1487
1488 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1489
1490 /* The following macros define the characters that are quoted by quote_ldap and
1491 quote_ldap_dn, respectively. */
1492
1493 #define LDAP_QUOTE "*()\\"
1494 #define LDAP_DN_QUOTE ",+\"\\<>;"
1495
1496
1497
1498 static uschar *
1499 eldap_quote(uschar *s, uschar *opt)
1500 {
1501 register int c;
1502 int count = 0;
1503 int len = 0;
1504 BOOL dn = FALSE;
1505 uschar *t = s;
1506 uschar *quoted;
1507
1508 /* Test for a DN quotation. */
1509
1510 if (opt != NULL)
1511 {
1512 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1513 dn = TRUE;
1514 }
1515
1516 /* Compute how much extra store we need for the string. This doesn't have to be
1517 exact as long as it isn't an underestimate. The worst case is the addition of 5
1518 extra bytes for a single character. This occurs for certain characters in DNs,
1519 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1520 possibly escaped character. The really fast way would be just to test for
1521 non-alphanumerics, but it is probably better to spot a few others that are
1522 never escaped, because if there are no specials at all, we can avoid copying
1523 the string. */
1524
1525 while ((c = *t++) != 0)
1526 {
1527 len++;
1528 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1529 }
1530 if (count == 0) return s;
1531
1532 /* Get sufficient store to hold the quoted string */
1533
1534 t = quoted = store_get(len + count + 1);
1535
1536 /* Handle plain quote_ldap */
1537
1538 if (!dn)
1539 {
1540 while ((c = *s++) != 0)
1541 {
1542 if (!isalnum(c))
1543 {
1544 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1545 {
1546 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1547 t += 5;
1548 continue;
1549 }
1550 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1551 {
1552 sprintf(CS t, "%%%02X", c);
1553 t += 3;
1554 continue;
1555 }
1556 }
1557 *t++ = c; /* unquoted character */
1558 }
1559 }
1560
1561 /* Handle quote_ldap_dn */
1562
1563 else
1564 {
1565 uschar *ss = s + len;
1566
1567 /* Find the last char before any trailing spaces */
1568
1569 while (ss > s && ss[-1] == ' ') ss--;
1570
1571 /* Quote leading spaces and sharps */
1572
1573 for (; s < ss; s++)
1574 {
1575 if (*s != ' ' && *s != '#') break;
1576 sprintf(CS t, "%%5C%%%02X", *s);
1577 t += 6;
1578 }
1579
1580 /* Handle the rest of the string, up to the trailing spaces */
1581
1582 while (s < ss)
1583 {
1584 c = *s++;
1585 if (!isalnum(c))
1586 {
1587 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1588 {
1589 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1590 t += 3; /* fall through to check URL */
1591 }
1592 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1593 {
1594 sprintf(CS t, "%%%02X", c);
1595 t += 3;
1596 continue;
1597 }
1598 }
1599 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1600 }
1601
1602 /* Handle the trailing spaces */
1603
1604 while (*ss++ != 0)
1605 {
1606 Ustrncpy(t, "%5C%20", 6);
1607 t += 6;
1608 }
1609 }
1610
1611 /* Terminate the new string and return */
1612
1613 *t = 0;
1614 return quoted;
1615 }
1616
1617
1618
1619 /*************************************************
1620 * Version reporting entry point *
1621 *************************************************/
1622
1623 /* See local README for interface description. */
1624
1625 #include "../version.h"
1626
1627 void
1628 ldap_version_report(FILE *f)
1629 {
1630 #ifdef DYNLOOKUP
1631 fprintf(f, "Library version: LDAP: Exim version %s\n", EXIM_VERSION_STR);
1632 #endif
1633 }
1634
1635
1636 static lookup_info ldap_lookup_info = {
1637 US"ldap", /* lookup name */
1638 lookup_querystyle, /* query-style lookup */
1639 eldap_open, /* open function */
1640 NULL, /* check function */
1641 eldap_find, /* find function */
1642 NULL, /* no close function */
1643 eldap_tidy, /* tidy function */
1644 eldap_quote, /* quoting function */
1645 ldap_version_report /* version reporting */
1646 };
1647
1648 static lookup_info ldapdn_lookup_info = {
1649 US"ldapdn", /* lookup name */
1650 lookup_querystyle, /* query-style lookup */
1651 eldap_open, /* sic */ /* open function */
1652 NULL, /* check function */
1653 eldapdn_find, /* find function */
1654 NULL, /* no close function */
1655 eldap_tidy, /* sic */ /* tidy function */
1656 eldap_quote, /* sic */ /* quoting function */
1657 NULL /* no version reporting (redundant) */
1658 };
1659
1660 static lookup_info ldapm_lookup_info = {
1661 US"ldapm", /* lookup name */
1662 lookup_querystyle, /* query-style lookup */
1663 eldap_open, /* sic */ /* open function */
1664 NULL, /* check function */
1665 eldapm_find, /* find function */
1666 NULL, /* no close function */
1667 eldap_tidy, /* sic */ /* tidy function */
1668 eldap_quote, /* sic */ /* quoting function */
1669 NULL /* no version reporting (redundant) */
1670 };
1671
1672 #ifdef DYNLOOKUP
1673 #define ldap_lookup_module_info _lookup_module_info
1674 #endif
1675
1676 static lookup_info *_lookup_list[] = { &ldap_lookup_info, &ldapdn_lookup_info, &ldapm_lookup_info };
1677 lookup_module_info ldap_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
1678
1679 /* End of lookups/ldap.c */