77ed940fd29784742f634e2424755bb6cbcab823
[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
804 /* In case we requested one attribute only but got
805 * several times into that attr loop, we need to append
806 * the additional values. (This may happen if you derive
807 * attributeTypes B and C from A and then query for A.)
808 * In all other cases we detect the different attribute
809 * and append only every non first value. */
810 if ((attr_count == 1 && data) || (values != firstval))
811 data = string_cat(data, &size, &ptr, US",", 1);
812
813 /* For multiple attributes, the data is in quotes. We must escape
814 internal quotes, backslashes, newlines, and must double commas. */
815
816 if (attrs_requested != 1)
817 {
818 int j;
819 for (j = 0; j < len; j++)
820 {
821 if (value[j] == '\n')
822 data = string_cat(data, &size, &ptr, US"\\n", 2);
823 else if (value[j] == ',')
824 data = string_cat(data, &size, &ptr, US",,", 2);
825 else
826 {
827 if (value[j] == '\"' || value[j] == '\\')
828 data = string_cat(data, &size, &ptr, US"\\", 1);
829 data = string_cat(data, &size, &ptr, value+j, 1);
830 }
831 }
832 }
833
834 /* For single attributes, just double commas */
835
836 else
837 {
838 int j;
839 for (j = 0; j < len; j++)
840 {
841 if (value[j] == ',')
842 data = string_cat(data, &size, &ptr, US",,", 2);
843 else
844 data = string_cat(data, &size, &ptr, value+j, 1);
845 }
846 }
847
848
849 /* Move on to the next value */
850
851 values++;
852 attribute_found = TRUE;
853 }
854
855 /* Closing quote at the end of the data for a named attribute. */
856
857 if (attrs_requested != 1)
858 data = string_cat(data, &size, &ptr, US"\"", 1);
859
860 /* Free the values */
861
862 ldap_value_free(CSS firstval);
863 }
864 }
865
866 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
867
868 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
869 to be freed. UMich LDAP stores them in static storage and does not require
870 this. */
871
872 ldap_memfree(attr);
873 #endif
874 } /* End "for" loop for extracting attributes from an entry */
875 } /* End "for" loop for extracting entries from a result */
876
877 /* Free the result */
878
879 ldap_msgfree(result);
880 result = NULL;
881 } /* End "while" loop for multiple results */
882
883 /* Terminate the dynamic string that we have built and reclaim unused store */
884
885 if (data != NULL)
886 {
887 data[ptr] = 0;
888 store_reset(data + ptr + 1);
889 }
890
891 /* Copy the last dn into eldap_dn */
892
893 if (dn != NULL)
894 {
895 eldap_dn = string_copy(dn);
896 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
897 ldap_memfree(dn);
898 #else /* OPENLDAP 1, UMich, Solaris */
899 free(dn);
900 #endif
901 }
902
903 DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
904
905 if (rc == 0)
906 {
907 *errmsg = US"ldap_result timed out";
908 goto RETURN_ERROR;
909 }
910
911 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
912 provide you with a message". Other error states seem to exist where
913 ldap_result() didn't give us any message from the server at all, leaving result
914 set to NULL. Apparently, "the error parameters of the LDAP session handle will
915 be set accordingly". That's the best we can do to retrieve an error status; we
916 can't use functions like ldap_result2error because they parse a message from
917 the server, which we didn't get.
918
919 Annoyingly, the different implementations of LDAP have gone for different
920 methods of handling error codes and generating error messages. */
921
922 if (rc == -1 || result == NULL)
923 {
924 int err;
925 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
926
927 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
928 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
929 *errmsg = string_sprintf("ldap_result failed: %d, %s",
930 err, ldap_err2string(err));
931
932 #elif defined LDAP_LIB_NETSCAPE
933 /* Dubious (surely 'matched' is spurious here?) */
934 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
935 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
936
937 #else /* UMich LDAP aka OpenLDAP 1.x */
938 *errmsg = string_sprintf("ldap_result failed: %d, %s",
939 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
940 #endif
941
942 goto RETURN_ERROR;
943 }
944
945 /* A return code that isn't -1 doesn't necessarily mean there were no problems
946 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
947 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
948 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
949 we don't provide that functionality when we can't. :-) */
950
951 if (rc != LDAP_RES_SEARCH_RESULT
952 #ifdef LDAP_RES_SEARCH_REFERENCE
953 && rc != LDAP_RES_SEARCH_REFERENCE
954 #endif
955 )
956 {
957 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
958 goto RETURN_ERROR;
959 }
960
961 /* We have a result message from the server. This doesn't yet mean all is well.
962 We need to parse the message to find out exactly what's happened. */
963
964 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
965 ldap_rc = rc;
966 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
967 CSS &error2, NULL, NULL, 0);
968 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
969 if (ldap_parse_rc < 0 &&
970 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
971 #ifdef LDAP_RES_SEARCH_REFERENCE
972 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
973 #endif
974 ))
975 {
976 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
977 goto RETURN_ERROR;
978 }
979 error1 = US ldap_err2string(rc);
980
981 #elif defined LDAP_LIB_NETSCAPE
982 /* Dubious (it doesn't reference 'result' at all!) */
983 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
984
985 #else /* UMich LDAP aka OpenLDAP 1.x */
986 rc = ldap_result2error(lcp->ld, result, 0);
987 error1 = ldap_err2string(rc);
988 error2 = lcp->ld->ld_error;
989 matched = lcp->ld->ld_matched;
990 #endif
991
992 /* Process the status as follows:
993
994 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
995 truncated result list.
996
997 (2) If we get LDAP_RES_SEARCH_REFERENCE, also just carry on. This was a
998 submitted patch that is reported to "do the right thing" with Solaris
999 LDAP libraries. (The problem it addresses apparently does not occur with
1000 Open LDAP.)
1001
1002 (3) The range of errors defined by LDAP_NAME_ERROR generally mean "that
1003 object does not, or cannot, exist in the database". For those cases we
1004 fail the lookup.
1005
1006 (4) All other non-successes here are treated as some kind of problem with
1007 the lookup, so return DEFER (which is the default in error_yield).
1008 */
1009
1010 DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
1011 rc, ldap_err2string(rc));
1012
1013 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED
1014 #ifdef LDAP_RES_SEARCH_REFERENCE
1015 && rc != LDAP_RES_SEARCH_REFERENCE
1016 #endif
1017 )
1018 {
1019 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
1020 rc,
1021 (error1 != NULL)? error1 : US"",
1022 (error2 != NULL && error2[0] != 0)? US"/" : US"",
1023 (error2 != NULL)? error2 : US"",
1024 (matched != NULL && matched[0] != 0)? US"/" : US"",
1025 (matched != NULL)? matched : US"");
1026
1027 #if defined LDAP_NAME_ERROR
1028 if (LDAP_NAME_ERROR(rc))
1029 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
1030 if (NAME_ERROR(rc))
1031 #else
1032 if (rc == LDAP_NO_SUCH_OBJECT)
1033 #endif
1034
1035 {
1036 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
1037 error_yield = FAIL;
1038 }
1039 goto RETURN_ERROR;
1040 }
1041
1042 /* The search succeeded. Check if we have too many results */
1043
1044 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
1045 {
1046 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
1047 "(filter not specific enough?)", rescount);
1048 goto RETURN_ERROR_BREAK;
1049 }
1050
1051 /* Check if we have too few (zero) entries */
1052
1053 if (rescount < 1)
1054 {
1055 *errmsg = string_sprintf("LDAP search: no results");
1056 error_yield = FAIL;
1057 goto RETURN_ERROR_BREAK;
1058 }
1059
1060 /* If an entry was found, but it had no attributes, we behave as if no entries
1061 were found, that is, the lookup failed. */
1062
1063 if (!attribute_found)
1064 {
1065 *errmsg = US"LDAP search: found no attributes";
1066 error_yield = FAIL;
1067 goto RETURN_ERROR;
1068 }
1069
1070 /* Otherwise, it's all worked */
1071
1072 DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
1073 *res = data;
1074
1075 RETURN_OK:
1076 if (result != NULL) ldap_msgfree(result);
1077 ldap_free_urldesc(ludp);
1078 return OK;
1079
1080 /* Error returns */
1081
1082 RETURN_ERROR_BREAK:
1083 *defer_break = TRUE;
1084
1085 RETURN_ERROR:
1086 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1087
1088 RETURN_ERROR_NOMSG:
1089 if (result != NULL) ldap_msgfree(result);
1090 if (ludp != NULL) ldap_free_urldesc(ludp);
1091
1092 #if defined LDAP_LIB_OPENLDAP2
1093 if (error2 != NULL) ldap_memfree(error2);
1094 if (matched != NULL) ldap_memfree(matched);
1095 #endif
1096
1097 return error_yield;
1098 }
1099
1100
1101
1102 /*************************************************
1103 * Internal search control function *
1104 *************************************************/
1105
1106 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
1107 and eldapm_find() with a difference in the "search_type" argument. It controls
1108 calls to perform_ldap_search() which actually does the work. We call that
1109 repeatedly for certain types of defer in the case when the URL contains no host
1110 name and eldap_default_servers is set to a list of servers to try. This gives
1111 more control than just passing over a list of hosts to ldap_open() because it
1112 handles other kinds of defer as well as just a failure to open. Note that the
1113 URL is defined to contain either zero or one "hostport" only.
1114
1115 Parameter data in addition to the URL can be passed as preceding text in the
1116 string, as items of the form XXX=yyy. The URL itself can be detected because it
1117 must begin "ldapx://", where x is empty, s, or i.
1118
1119 Arguments:
1120 ldap_url the URL to be looked up, optionally preceded by other parameter
1121 settings
1122 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
1123 SEARCH_LDAP_SINGLE allows values from one entry only
1124 SEARCH_LDAP_DN gets the DN from one entry
1125 res set to point at the result
1126 errmsg set to point a message if result is not OK
1127
1128 Returns: OK or FAIL or DEFER
1129 */
1130
1131 static int
1132 control_ldap_search(const uschar *ldap_url, int search_type, uschar **res,
1133 uschar **errmsg)
1134 {
1135 BOOL defer_break = FALSE;
1136 int timelimit = LDAP_NO_LIMIT;
1137 int sizelimit = LDAP_NO_LIMIT;
1138 int tcplimit = 0;
1139 int sep = 0;
1140 int dereference = LDAP_DEREF_NEVER;
1141 void* referrals = LDAP_OPT_ON;
1142 const uschar *url = ldap_url;
1143 const uschar *p;
1144 uschar *user = NULL;
1145 uschar *password = NULL;
1146 uschar *local_servers = NULL;
1147 uschar *server;
1148 const uschar *list;
1149 uschar buffer[512];
1150
1151 while (isspace(*url)) url++;
1152
1153 /* Until the string begins "ldap", search for the other parameter settings that
1154 are recognized. They are of the form NAME=VALUE, with the value being
1155 optionally double-quoted. There must still be a space after it, however. No
1156 NAME has the value "ldap". */
1157
1158 while (strncmpic(url, US"ldap", 4) != 0)
1159 {
1160 const uschar *name = url;
1161 while (*url != 0 && *url != '=') url++;
1162 if (*url == '=')
1163 {
1164 int namelen;
1165 uschar *value;
1166 namelen = ++url - name;
1167 value = string_dequote(&url);
1168 if (isspace(*url))
1169 {
1170 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1171 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1172 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1173 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1174 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1175 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1176 else if (strncmpic(name, US"SERVERS=", namelen) == 0) local_servers = value;
1177
1178 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1179
1180 #ifdef LDAP_OPT_DEREF
1181 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1182 {
1183 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1184 else if (strcmpic(value, US"searching") == 0)
1185 dereference = LDAP_DEREF_SEARCHING;
1186 else if (strcmpic(value, US"finding") == 0)
1187 dereference = LDAP_DEREF_FINDING;
1188 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1189 }
1190 #else
1191 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1192 {
1193 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1194 "library - cannot use \"dereference\"");
1195 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1196 return DEFER;
1197 }
1198 #endif
1199
1200 #ifdef LDAP_OPT_REFERRALS
1201 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1202 {
1203 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1204 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1205 else
1206 {
1207 *errmsg = string_sprintf("LDAP option REFERRALS is not \"follow\" "
1208 "or \"nofollow\"");
1209 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1210 return DEFER;
1211 }
1212 }
1213 #else
1214 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1215 {
1216 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1217 "library - cannot use \"referrals\"");
1218 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1219 return DEFER;
1220 }
1221 #endif
1222
1223 else
1224 {
1225 *errmsg =
1226 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1227 namelen, name);
1228 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1229 return DEFER;
1230 }
1231 while (isspace(*url)) url++;
1232 continue;
1233 }
1234 }
1235 *errmsg = US"malformed parameter setting precedes LDAP URL";
1236 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1237 return DEFER;
1238 }
1239
1240 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1241 but it seems that not all behave like this. The DN for the user is often the
1242 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1243 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1244 far too complicated. */
1245
1246 if (user != NULL)
1247 {
1248 uschar *s;
1249 uschar *t = user;
1250 for (s = user; *s != 0; s++)
1251 {
1252 int c, d;
1253 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1254 {
1255 c = tolower(c);
1256 d = tolower(d);
1257 *t++ =
1258 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1259 ((d >= 'a')? (10 + d - 'a') : d - '0');
1260 s += 2;
1261 }
1262 else *t++ = *s;
1263 }
1264 *t = 0;
1265 }
1266
1267 DEBUG(D_lookup)
1268 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1269 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1270 tcplimit, dereference, (referrals == LDAP_OPT_ON)? "on" : "off");
1271
1272 /* If the request is just to check authentication, some credentials must
1273 be given. The password must not be empty because LDAP binds with an empty
1274 password are considered anonymous, and will succeed on most installations. */
1275
1276 if (search_type == SEARCH_LDAP_AUTH)
1277 {
1278 if (user == NULL || password == NULL)
1279 {
1280 *errmsg = US"ldapauth lookups must specify the username and password";
1281 return DEFER;
1282 }
1283 if (password[0] == 0)
1284 {
1285 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1286 return FAIL;
1287 }
1288 }
1289
1290 /* Check for valid ldap url starters */
1291
1292 p = url + 4;
1293 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1294 if (Ustrncmp(p, "://", 3) != 0)
1295 {
1296 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1297 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1298 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1299 return DEFER;
1300 }
1301
1302 /* No default servers, or URL contains a server name: just one attempt */
1303
1304 if ((eldap_default_servers == NULL && local_servers == NULL) || p[3] != '/')
1305 {
1306 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1307 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1308 referrals);
1309 }
1310
1311 /* Loop through the default servers until OK or FAIL. Use local_servers list
1312 * if defined in the lookup, otherwise use the global default list */
1313 list = (local_servers == NULL) ? eldap_default_servers : local_servers;
1314 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1315 {
1316 int rc;
1317 int port = 0;
1318 uschar *colon = Ustrchr(server, ':');
1319 if (colon != NULL)
1320 {
1321 *colon = 0;
1322 port = Uatoi(colon+1);
1323 }
1324 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1325 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1326 referrals);
1327 if (rc != DEFER || defer_break) return rc;
1328 }
1329
1330 return DEFER;
1331 }
1332
1333
1334
1335 /*************************************************
1336 * Find entry point *
1337 *************************************************/
1338
1339 /* See local README for interface description. The different kinds of search
1340 are handled by a common function, with a flag to differentiate between them.
1341 The handle and filename arguments are not used. */
1342
1343 static int
1344 eldap_find(void *handle, uschar *filename, const uschar *ldap_url, int length,
1345 uschar **result, uschar **errmsg, uint *do_cache)
1346 {
1347 /* Keep picky compilers happy */
1348 do_cache = do_cache;
1349 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1350 }
1351
1352 static int
1353 eldapm_find(void *handle, uschar *filename, const uschar *ldap_url, int length,
1354 uschar **result, uschar **errmsg, uint *do_cache)
1355 {
1356 /* Keep picky compilers happy */
1357 do_cache = do_cache;
1358 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1359 }
1360
1361 static int
1362 eldapdn_find(void *handle, uschar *filename, const uschar *ldap_url, int length,
1363 uschar **result, uschar **errmsg, uint *do_cache)
1364 {
1365 /* Keep picky compilers happy */
1366 do_cache = do_cache;
1367 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1368 }
1369
1370 int
1371 eldapauth_find(void *handle, uschar *filename, const uschar *ldap_url, int length,
1372 uschar **result, uschar **errmsg, uint *do_cache)
1373 {
1374 /* Keep picky compilers happy */
1375 do_cache = do_cache;
1376 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1377 }
1378
1379
1380
1381 /*************************************************
1382 * Open entry point *
1383 *************************************************/
1384
1385 /* See local README for interface description. */
1386
1387 static void *
1388 eldap_open(uschar *filename, uschar **errmsg)
1389 {
1390 return (void *)(1); /* Just return something non-null */
1391 }
1392
1393
1394
1395 /*************************************************
1396 * Tidy entry point *
1397 *************************************************/
1398
1399 /* See local README for interface description.
1400 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1401
1402 static void
1403 eldap_tidy(void)
1404 {
1405 LDAP_CONNECTION *lcp = NULL;
1406 eldap_dn = NULL;
1407
1408 while ((lcp = ldap_connections) != NULL)
1409 {
1410 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1411 lcp->port);
1412 if(lcp->bound == TRUE)
1413 ldap_unbind(lcp->ld);
1414 ldap_connections = lcp->next;
1415 }
1416 }
1417
1418
1419
1420 /*************************************************
1421 * Quote entry point *
1422 *************************************************/
1423
1424 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1425 quoting have to be done: LDAP quoting, and URL quoting. The current
1426 specification is the result of a suggestion by Brian Candler. It recognizes
1427 two separate cases:
1428
1429 (1) For text that appears in a search filter, the following escapes are
1430 required (see RFC 2254):
1431
1432 * -> \2A
1433 ( -> \28
1434 ) -> \29
1435 \ -> \5C
1436 NULL -> \00
1437
1438 Then the entire filter text must be URL-escaped. This kind of quoting is
1439 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1440 in the input string, because that's a terminator.
1441
1442 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1443
1444 , + " \ < > ;
1445
1446 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1447 must be escaped, as must a leading #. Then the string must be URL-quoted.
1448 This type of quoting is implemented by ${quote_ldap_dn:....}.
1449
1450 For URL quoting, the only characters that need not be quoted are the
1451 alphamerics and
1452
1453 ! $ ' ( ) * + - . _
1454
1455 All the others must be hexified and preceded by %. This includes the
1456 backslashes used for LDAP quoting.
1457
1458 For a DN that is given in the USER parameter for authentication, we need the
1459 same initial quoting as (2) but in this case, the result must NOT be
1460 URL-escaped, because it isn't a URL. The way this is handled is by
1461 de-URL-quoting the text when processing the USER parameter in
1462 control_ldap_search() above. That means that the same quote operator can be
1463 used. This has the additional advantage that spaces in the DN won't cause
1464 parsing problems. For example:
1465
1466 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1467
1468 should be safe if there are spaces in $1.
1469
1470
1471 Arguments:
1472 s the string to be quoted
1473 opt additional option text or NULL if none
1474 only "dn" is recognized
1475
1476 Returns: the processed string or NULL for a bad option
1477 */
1478
1479
1480
1481 /* The characters in this string, together with alphanumerics, never need
1482 quoting in any way. */
1483
1484 #define ALWAYS_LITERAL "!$'-._"
1485
1486 /* The special characters in this string do not need to be URL-quoted. The set
1487 is a bit larger than the general literals. */
1488
1489 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1490
1491 /* The following macros define the characters that are quoted by quote_ldap and
1492 quote_ldap_dn, respectively. */
1493
1494 #define LDAP_QUOTE "*()\\"
1495 #define LDAP_DN_QUOTE ",+\"\\<>;"
1496
1497
1498
1499 static uschar *
1500 eldap_quote(uschar *s, uschar *opt)
1501 {
1502 register int c;
1503 int count = 0;
1504 int len = 0;
1505 BOOL dn = FALSE;
1506 uschar *t = s;
1507 uschar *quoted;
1508
1509 /* Test for a DN quotation. */
1510
1511 if (opt != NULL)
1512 {
1513 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1514 dn = TRUE;
1515 }
1516
1517 /* Compute how much extra store we need for the string. This doesn't have to be
1518 exact as long as it isn't an underestimate. The worst case is the addition of 5
1519 extra bytes for a single character. This occurs for certain characters in DNs,
1520 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1521 possibly escaped character. The really fast way would be just to test for
1522 non-alphanumerics, but it is probably better to spot a few others that are
1523 never escaped, because if there are no specials at all, we can avoid copying
1524 the string. */
1525
1526 while ((c = *t++) != 0)
1527 {
1528 len++;
1529 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1530 }
1531 if (count == 0) return s;
1532
1533 /* Get sufficient store to hold the quoted string */
1534
1535 t = quoted = store_get(len + count + 1);
1536
1537 /* Handle plain quote_ldap */
1538
1539 if (!dn)
1540 {
1541 while ((c = *s++) != 0)
1542 {
1543 if (!isalnum(c))
1544 {
1545 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1546 {
1547 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1548 t += 5;
1549 continue;
1550 }
1551 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1552 {
1553 sprintf(CS t, "%%%02X", c);
1554 t += 3;
1555 continue;
1556 }
1557 }
1558 *t++ = c; /* unquoted character */
1559 }
1560 }
1561
1562 /* Handle quote_ldap_dn */
1563
1564 else
1565 {
1566 uschar *ss = s + len;
1567
1568 /* Find the last char before any trailing spaces */
1569
1570 while (ss > s && ss[-1] == ' ') ss--;
1571
1572 /* Quote leading spaces and sharps */
1573
1574 for (; s < ss; s++)
1575 {
1576 if (*s != ' ' && *s != '#') break;
1577 sprintf(CS t, "%%5C%%%02X", *s);
1578 t += 6;
1579 }
1580
1581 /* Handle the rest of the string, up to the trailing spaces */
1582
1583 while (s < ss)
1584 {
1585 c = *s++;
1586 if (!isalnum(c))
1587 {
1588 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1589 {
1590 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1591 t += 3; /* fall through to check URL */
1592 }
1593 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1594 {
1595 sprintf(CS t, "%%%02X", c);
1596 t += 3;
1597 continue;
1598 }
1599 }
1600 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1601 }
1602
1603 /* Handle the trailing spaces */
1604
1605 while (*ss++ != 0)
1606 {
1607 Ustrncpy(t, "%5C%20", 6);
1608 t += 6;
1609 }
1610 }
1611
1612 /* Terminate the new string and return */
1613
1614 *t = 0;
1615 return quoted;
1616 }
1617
1618
1619
1620 /*************************************************
1621 * Version reporting entry point *
1622 *************************************************/
1623
1624 /* See local README for interface description. */
1625
1626 #include "../version.h"
1627
1628 void
1629 ldap_version_report(FILE *f)
1630 {
1631 #ifdef DYNLOOKUP
1632 fprintf(f, "Library version: LDAP: Exim version %s\n", EXIM_VERSION_STR);
1633 #endif
1634 }
1635
1636
1637 static lookup_info ldap_lookup_info = {
1638 US"ldap", /* lookup name */
1639 lookup_querystyle, /* query-style lookup */
1640 eldap_open, /* open function */
1641 NULL, /* check function */
1642 eldap_find, /* find function */
1643 NULL, /* no close function */
1644 eldap_tidy, /* tidy function */
1645 eldap_quote, /* quoting function */
1646 ldap_version_report /* version reporting */
1647 };
1648
1649 static lookup_info ldapdn_lookup_info = {
1650 US"ldapdn", /* lookup name */
1651 lookup_querystyle, /* query-style lookup */
1652 eldap_open, /* sic */ /* open function */
1653 NULL, /* check function */
1654 eldapdn_find, /* find function */
1655 NULL, /* no close function */
1656 eldap_tidy, /* sic */ /* tidy function */
1657 eldap_quote, /* sic */ /* quoting function */
1658 NULL /* no version reporting (redundant) */
1659 };
1660
1661 static lookup_info ldapm_lookup_info = {
1662 US"ldapm", /* lookup name */
1663 lookup_querystyle, /* query-style lookup */
1664 eldap_open, /* sic */ /* open function */
1665 NULL, /* check function */
1666 eldapm_find, /* find function */
1667 NULL, /* no close function */
1668 eldap_tidy, /* sic */ /* tidy function */
1669 eldap_quote, /* sic */ /* quoting function */
1670 NULL /* no version reporting (redundant) */
1671 };
1672
1673 #ifdef DYNLOOKUP
1674 #define ldap_lookup_module_info _lookup_module_info
1675 #endif
1676
1677 static lookup_info *_lookup_list[] = { &ldap_lookup_info, &ldapdn_lookup_info, &ldapm_lookup_info };
1678 lookup_module_info ldap_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
1679
1680 /* End of lookups/ldap.c */