Bug 1453: Add SERVERS ldap server list override
[exim.git] / src / src / lookups / ldap.c
CommitLineData
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
5a66c31b 5/* Copyright (c) University of Cambridge 1995 - 2014 */
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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
9driver. Further contibutions from Michael Haardt, Brian Candler, Barry
10Pederson, Peter Savitch and Christian Kellner. Particular thanks to Brian for
11researching how to handle the different kinds of error. */
12
13
14#include "../exim.h"
15#include "lf_functions.h"
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16
17
765b530f
PH
18/* Include LDAP headers. The code below uses some "old" LDAP interfaces that
19are deprecated in OpenLDAP. I don't know their status in other LDAP
20implementations. LDAP_DEPRECATED causes their prototypes to be defined in
21ldap.h. */
22
23#define LDAP_DEPRECATED 1
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PH
24
25#include <lber.h>
26#include <ldap.h>
27
28
29/* Annoyingly, the different LDAP libraries handle errors in different ways,
30and some other things too. There doesn't seem to be an automatic way of
31distinguishing between them. Local/Makefile should contain a setting of
32LDAP_LIB_TYPE, which in turn causes appropriate macros to be defined for the
33different kinds. Those that matter are:
34
35LDAP_LIB_NETSCAPE
36LDAP_LIB_SOLARIS with synonym LDAP_LIB_SOLARIS7
37LDAP_LIB_OPENLDAP2
38
39These others may be defined, but are in fact the default, so are not tested:
40
41LDAP_LIB_UMICHIGAN
42LDAP_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
0756eb3c
PH
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
72SEARCH_LDAP_DN lookup). */
73
74
75/* Structure and anchor for caching connections. */
76
77typedef struct ldap_connection {
78 struct ldap_connection *next;
79 uschar *host;
80 uschar *user;
81 uschar *password;
82 BOOL bound;
83 int port;
a30a8861 84 BOOL is_start_tls_called;
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PH
85 LDAP *ld;
86} LDAP_CONNECTION;
87
88static 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
97via control_ldap_search) from eldap_find(), eldapauth_find(), eldapdn_find(),
98and eldapm_find(), with a difference in the "search_type" argument.
99
100The case of eldapauth_find() is special in that all it does is do
101authentication, returning OK or FAIL as appropriate. This isn't used as a
102lookup. Instead, it is called from expand.c as an expansion condition test.
103
104The DN from a successful lookup is placed in $ldap_dn. This feature postdates
105the provision of the SEARCH_LDAP_DN facility for returning just the DN as the
106data.
107
108Arguments:
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
d00328e2 122 tcplimit max time for network activity, e.g. connect, or 0 for OS default
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PH
123 deference the dereference option, which is one of
124 LDAP_DEREF_{NEVER,SEARCHING,FINDING,ALWAYS}
6ec97b1b 125 referrals the referral option, which is LDAP_OPT_ON or LDAP_OPT_OFF
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PH
126
127Returns: OK or FAIL or DEFER
128 FAIL is given only if a lookup was performed successfully, but
129 returned no data.
130*/
131
132static int
133perform_ldap_search(uschar *ldap_url, uschar *server, int s_port, int search_type,
134 uschar **res, uschar **errmsg, BOOL *defer_break, uschar *user, uschar *password,
6ec97b1b 135 int sizelimit, int timelimit, int tcplimit, int dereference, void *referrals)
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PH
136{
137LDAPURLDesc *ludp = NULL;
138LDAPMessage *result = NULL;
139BerElement *ber;
140LDAP_CONNECTION *lcp;
141
142struct timeval timeout;
143struct timeval *timeoutptr = NULL;
144
145uschar *attr;
146uschar **attrp;
147uschar *data = NULL;
148uschar *dn = NULL;
149uschar *host;
150uschar **values;
151uschar **firstval;
152uschar porttext[16];
153
154uschar *error1 = NULL; /* string representation of errcode (static) */
155uschar *error2 = NULL; /* error message from the server */
156uschar *matched = NULL; /* partially matched DN */
157
158int attr_count = 0;
159int error_yield = DEFER;
160int msgid;
d38f8232 161int rc, ldap_rc, ldap_parse_rc;
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162int port;
163int ptr = 0;
164int rescount = 0;
165int size = 0;
166BOOL attribute_found = FALSE;
167BOOL ldapi = FALSE;
168
169DEBUG(D_lookup)
170 debug_printf("perform_ldap_search: ldap%s URL = \"%s\" server=%s port=%d "
171 "sizelimit=%d timelimit=%d tcplimit=%d\n",
172 (search_type == SEARCH_LDAP_MULTIPLE)? "m" :
173 (search_type == SEARCH_LDAP_DN)? "dn" :
174 (search_type == SEARCH_LDAP_AUTH)? "auth" : "",
175 ldap_url, server, s_port, sizelimit, timelimit, tcplimit);
176
177/* Check if LDAP thinks the URL is a valid LDAP URL. We assume that if the LDAP
178library that is in use doesn't recognize, say, "ldapi", it will barf here. */
179
180if (!ldap_is_ldap_url(CS ldap_url))
181 {
182 *errmsg = string_sprintf("ldap_is_ldap_url: not an LDAP url \"%s\"\n",
183 ldap_url);
184 goto RETURN_ERROR_BREAK;
185 }
186
187/* Parse the URL */
188
189if ((rc = ldap_url_parse(CS ldap_url, &ludp)) != 0)
190 {
191 *errmsg = string_sprintf("ldap_url_parse: (error %d) parsing \"%s\"\n", rc,
192 ldap_url);
193 goto RETURN_ERROR_BREAK;
194 }
195
196/* If the host name is empty, take it from the separate argument, if one is
197given. OpenLDAP 2.0.6 sets an unset hostname to "" rather than empty, but
198expects NULL later in ldap_init() to mean "default", annoyingly. In OpenLDAP
1992.0.11 this has changed (it uses NULL). */
200
201if ((ludp->lud_host == NULL || ludp->lud_host[0] == 0) && server != NULL)
202 {
203 host = server;
204 port = s_port;
205 }
206else
207 {
208 host = US ludp->lud_host;
209 if (host != NULL && host[0] == 0) host = NULL;
210 port = ludp->lud_port;
211 }
212
213DEBUG(D_lookup) debug_printf("after ldap_url_parse: host=%s port=%d\n",
214 host, port);
215
216if (port == 0) port = LDAP_PORT; /* Default if none given */
217sprintf(CS porttext, ":%d", port); /* For messages */
218
219/* If the "host name" is actually a path, we are going to connect using a Unix
220socket, regardless of whether "ldapi" was actually specified or not. This means
221that a Unix socket can be declared in eldap_default_servers, and "traditional"
222LDAP queries using just "ldap" can be used ("ldaps" is similarly overridden).
223The path may start with "/" or it may already be escaped as "%2F" if it was
224actually declared that way in eldap_default_servers. (I did it that way the
225first time.) If the host name is not a path, the use of "ldapi" causes an
226error, except in the default case. (But lud_scheme doesn't seem to exist in
227older libraries.) */
228
229if (host != NULL)
230 {
231 if ((host[0] == '/' || Ustrncmp(host, "%2F", 3) == 0))
232 {
233 ldapi = TRUE;
234 porttext[0] = 0; /* Remove port from messages */
235 }
236
237 #if defined LDAP_LIB_OPENLDAP2
238 else if (strncmp(ludp->lud_scheme, "ldapi", 5) == 0)
239 {
240 *errmsg = string_sprintf("ldapi requires an absolute path (\"%s\" given)",
241 host);
242 goto RETURN_ERROR;
243 }
244 #endif
245 }
246
247/* Count the attributes; we need this later to tell us how to format results */
248
249for (attrp = USS ludp->lud_attrs; attrp != NULL && *attrp != NULL; attrp++)
250 attr_count++;
251
252/* See if we can find a cached connection to this host. The port is not
253relevant for ldapi. The host name pointer is set to NULL if no host was given
254(implying the library default), rather than to the empty string. Note that in
255this case, there is no difference between ldap and ldapi. */
256
257for (lcp = ldap_connections; lcp != NULL; lcp = lcp->next)
258 {
259 if ((host == NULL) != (lcp->host == NULL) ||
260 (host != NULL && strcmpic(lcp->host, host) != 0))
261 continue;
262 if (ldapi || port == lcp->port) break;
263 }
264
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PH
265/* Use this network timeout in any requests. */
266
267if (tcplimit > 0)
268 {
269 timeout.tv_sec = tcplimit;
270 timeout.tv_usec = 0;
271 timeoutptr = &timeout;
272 }
273
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274/* If no cached connection found, we must open a connection to the server. If
275the server name is actually an absolute path, we set ldapi=TRUE above. This
276requests connection via a Unix socket. However, as far as I know, only OpenLDAP
277supports the use of sockets, and the use of ldap_initialize(). */
278
279if (lcp == NULL)
280 {
281 LDAP *ld;
282
5428a946
TL
283 #ifdef LDAP_OPT_X_TLS_NEWCTX
284 int am_server = 0;
285 LDAP *ldsetctx;
286 #else
287 LDAP *ldsetctx = NULL;
288 #endif
289
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290
291 /* --------------------------- OpenLDAP ------------------------ */
292
293 /* There seems to be a preference under OpenLDAP for ldap_initialize()
294 instead of ldap_init(), though I have as yet been unable to find
295 documentation that says this. (OpenLDAP documentation is sparse to
296 non-existent). So we handle OpenLDAP differently here. Also, support for
297 ldapi seems to be OpenLDAP-only at present. */
298
299 #ifdef LDAP_LIB_OPENLDAP2
300
301 /* We now need an empty string for the default host. Get some store in which
302 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
303 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
304 than the host name + "ldaps:///" plus : and a port number, say 20 + the
305 length of the host name. What we get should accommodate both, easily. */
306
307 uschar *shost = (host == NULL)? US"" : host;
308 uschar *init_url = store_get(20 + 3 * Ustrlen(shost));
309 uschar *init_ptr;
310
311 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
312 contain the path name, with slashes escaped as %2F. */
313
314 if (ldapi)
315 {
316 int ch;
317 init_ptr = init_url + 8;
318 Ustrcpy(init_url, "ldapi://");
319 while ((ch = *shost++) != 0)
320 {
321 if (ch == '/')
322 {
323 Ustrncpy(init_ptr, "%2F", 3);
324 init_ptr += 3;
325 }
326 else *init_ptr++ = ch;
327 }
328 *init_ptr = 0;
329 }
330
331 /* This is not an ldapi call. Just build a URI with the protocol type, host
332 name, and port. */
333
334 else
335 {
336 init_ptr = Ustrchr(ldap_url, '/');
337 Ustrncpy(init_url, ldap_url, init_ptr - ldap_url);
338 init_ptr = init_url + (init_ptr - ldap_url);
339 sprintf(CS init_ptr, "//%s:%d/", shost, port);
340 }
341
342 /* Call ldap_initialize() and check the result */
343
344 DEBUG(D_lookup) debug_printf("ldap_initialize with URL %s\n", init_url);
345 rc = ldap_initialize(&ld, CS init_url);
346 if (rc != LDAP_SUCCESS)
347 {
348 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
349 rc, init_url);
350 goto RETURN_ERROR;
351 }
352 store_reset(init_url); /* Might as well save memory when we can */
353
354
355 /* ------------------------- Not OpenLDAP ---------------------- */
356
357 /* For libraries other than OpenLDAP, use ldap_init(). */
358
359 #else /* LDAP_LIB_OPENLDAP2 */
360 ld = ldap_init(CS host, port);
361 #endif /* LDAP_LIB_OPENLDAP2 */
362
363 /* -------------------------------------------------------------- */
364
365
366 /* Handle failure to initialize */
367
368 if (ld == NULL)
369 {
370 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
371 host, porttext, strerror(errno));
372 goto RETURN_ERROR;
373 }
374
5428a946
TL
375 #ifdef LDAP_OPT_X_TLS_NEWCTX
376 ldsetctx = ld;
377 #endif
378
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379 /* Set the TCP connect time limit if available. This is something that is
380 in Netscape SDK v4.1; I don't know about other libraries. */
381
382 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
7c7ad977
PH
383 if (tcplimit > 0)
384 {
994a09e9 385 int timeout1000 = tcplimit*1000;
7c7ad977
PH
386 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
387 }
994a09e9
PH
388 else
389 {
390 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
391 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&notimeout);
392 }
0756eb3c
PH
393 #endif
394
7c7ad977
PH
395 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
396
397 #ifdef LDAP_OPT_NETWORK_TIMEOUT
398 if (tcplimit > 0)
399 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
8e669ac1 400 #endif
7c7ad977 401
0756eb3c
PH
402 /* I could not get TLS to work until I set the version to 3. That version
403 seems to be the default nowadays. The RFC is dated 1997, so I would hope
404 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
405 been set, go for v3 if we can. */
406
407 if (eldap_version < 0)
408 {
409 #ifdef LDAP_VERSION3
410 eldap_version = LDAP_VERSION3;
411 #else
412 eldap_version = 2;
413 #endif
414 }
415
416 #ifdef LDAP_OPT_PROTOCOL_VERSION
417 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
418 #endif
419
420 DEBUG(D_lookup) debug_printf("initialized for LDAP (v%d) server %s%s\n",
421 eldap_version, host, porttext);
422
423 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
424 for "ldaps" and soft otherwise. */
425
426 #ifdef LDAP_OPT_X_TLS
427 if (!ldapi)
428 {
429 int tls_option;
33382dd9
TL
430 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
431 if (eldap_require_cert != NULL)
432 {
433 tls_option = LDAP_OPT_X_TLS_NEVER;
434 if (Ustrcmp(eldap_require_cert, "hard") == 0)
435 {
436 tls_option = LDAP_OPT_X_TLS_HARD;
437 }
438 else if (Ustrcmp(eldap_require_cert, "demand") == 0)
439 {
440 tls_option = LDAP_OPT_X_TLS_DEMAND;
441 }
442 else if (Ustrcmp(eldap_require_cert, "allow") == 0)
443 {
444 tls_option = LDAP_OPT_X_TLS_ALLOW;
445 }
446 else if (Ustrcmp(eldap_require_cert, "try") == 0)
447 {
448 tls_option = LDAP_OPT_X_TLS_TRY;
449 }
450 DEBUG(D_lookup)
451 debug_printf("Require certificate overrides LDAP_OPT_X_TLS option (%d)\n",
452 tls_option);
453 }
454 else
455 #endif /* LDAP_OPT_X_TLS_REQUIRE_CERT */
0756eb3c
PH
456 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
457 {
458 tls_option = LDAP_OPT_X_TLS_HARD;
33382dd9
TL
459 DEBUG(D_lookup)
460 debug_printf("LDAP_OPT_X_TLS_HARD set due to ldaps:// URI\n");
0756eb3c
PH
461 }
462 else
463 {
464 tls_option = LDAP_OPT_X_TLS_TRY;
33382dd9
TL
465 DEBUG(D_lookup)
466 debug_printf("LDAP_OPT_X_TLS_TRY set due to ldap:// URI\n");
0756eb3c
PH
467 }
468 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
469 }
470 #endif /* LDAP_OPT_X_TLS */
471
bc19a55b
PP
472 #ifdef LDAP_OPT_X_TLS_CACERTFILE
473 if (eldap_ca_cert_file != NULL)
474 {
5428a946 475 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CACERTFILE, eldap_ca_cert_file);
bc19a55b
PP
476 }
477 #endif
478 #ifdef LDAP_OPT_X_TLS_CACERTDIR
479 if (eldap_ca_cert_dir != NULL)
480 {
5428a946 481 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CACERTDIR, eldap_ca_cert_dir);
bc19a55b
PP
482 }
483 #endif
484 #ifdef LDAP_OPT_X_TLS_CERTFILE
485 if (eldap_cert_file != NULL)
486 {
5428a946 487 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CERTFILE, eldap_cert_file);
bc19a55b
PP
488 }
489 #endif
490 #ifdef LDAP_OPT_X_TLS_KEYFILE
491 if (eldap_cert_key != NULL)
492 {
5428a946 493 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_KEYFILE, eldap_cert_key);
bc19a55b
PP
494 }
495 #endif
496 #ifdef LDAP_OPT_X_TLS_CIPHER_SUITE
497 if (eldap_cipher_suite != NULL)
498 {
5428a946 499 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CIPHER_SUITE, eldap_cipher_suite);
bc19a55b
PP
500 }
501 #endif
502 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
503 if (eldap_require_cert != NULL)
504 {
505 int cert_option = LDAP_OPT_X_TLS_NEVER;
506 if (Ustrcmp(eldap_require_cert, "hard") == 0)
507 {
508 cert_option = LDAP_OPT_X_TLS_HARD;
509 }
510 else if (Ustrcmp(eldap_require_cert, "demand") == 0)
511 {
512 cert_option = LDAP_OPT_X_TLS_DEMAND;
513 }
514 else if (Ustrcmp(eldap_require_cert, "allow") == 0)
515 {
516 cert_option = LDAP_OPT_X_TLS_ALLOW;
517 }
518 else if (Ustrcmp(eldap_require_cert, "try") == 0)
519 {
520 cert_option = LDAP_OPT_X_TLS_TRY;
521 }
5428a946
TL
522 /* This ldap handle is set at compile time based on client libs. Older
523 * versions want it to be global and newer versions can force a reload
524 * of the TLS context (to reload these settings we are changing from the
525 * default that loaded at instantiation). */
526 rc = ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_REQUIRE_CERT, &cert_option);
527 if (rc)
528 {
529 DEBUG(D_lookup)
530 debug_printf("Unable to set TLS require cert_option(%d) globally: %s\n",
531 cert_option, ldap_err2string(rc));
532 }
533 }
534 #endif
535 #ifdef LDAP_OPT_X_TLS_NEWCTX
536 rc = ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_NEWCTX, &am_server);
537 if (rc)
538 {
539 DEBUG(D_lookup)
540 debug_printf("Unable to reload TLS context %d: %s\n",
541 rc, ldap_err2string(rc));
bc19a55b
PP
542 }
543 #endif
544
0756eb3c
PH
545 /* Now add this connection to the chain of cached connections */
546
547 lcp = store_get(sizeof(LDAP_CONNECTION));
548 lcp->host = (host == NULL)? NULL : string_copy(host);
549 lcp->bound = FALSE;
550 lcp->user = NULL;
551 lcp->password = NULL;
552 lcp->port = port;
553 lcp->ld = ld;
554 lcp->next = ldap_connections;
a30a8861 555 lcp->is_start_tls_called = FALSE;
0756eb3c
PH
556 ldap_connections = lcp;
557 }
558
559/* Found cached connection */
560
561else
562 {
563 DEBUG(D_lookup)
564 debug_printf("re-using cached connection to LDAP server %s%s\n",
565 host, porttext);
566 }
567
568/* Bind with the user/password supplied, or an anonymous bind if these values
569are NULL, unless a cached connection is already bound with the same values. */
570
571if (!lcp->bound ||
572 (lcp->user == NULL && user != NULL) ||
573 (lcp->user != NULL && user == NULL) ||
574 (lcp->user != NULL && user != NULL && Ustrcmp(lcp->user, user) != 0) ||
575 (lcp->password == NULL && password != NULL) ||
576 (lcp->password != NULL && password == NULL) ||
577 (lcp->password != NULL && password != NULL &&
578 Ustrcmp(lcp->password, password) != 0))
579 {
580 DEBUG(D_lookup) debug_printf("%sbinding with user=%s password=%s\n",
581 (lcp->bound)? "re-" : "", user, password);
a30a8861 582 if (eldap_start_tls && !lcp->is_start_tls_called)
bc19a55b 583 {
d13cdd30
PP
584#if defined(LDAP_OPT_X_TLS) && !defined(LDAP_LIB_SOLARIS)
585 /* The Oracle LDAP libraries (LDAP_LIB_TYPE=SOLARIS) don't support this.
586 * Note: moreover, they appear to now define LDAP_OPT_X_TLS and still not
587 * export an ldap_start_tls_s symbol.
588 */
589 if ( (rc = ldap_start_tls_s(lcp->ld, NULL, NULL)) != LDAP_SUCCESS)
590 {
591 *errmsg = string_sprintf("failed to initiate TLS processing on an "
592 "LDAP session to server %s%s - ldap_start_tls_s() returned %d:"
593 " %s", host, porttext, rc, ldap_err2string(rc));
594 goto RETURN_ERROR;
595 }
a30a8861 596 lcp->is_start_tls_called = TRUE;
d13cdd30
PP
597#else
598 DEBUG(D_lookup)
599 debug_printf("TLS initiation not supported with this Exim and your LDAP library.\n");
867fcbf5 600#endif
d13cdd30 601 }
7c7ad977
PH
602 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
603 == -1)
0756eb3c 604 {
7c7ad977 605 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
d00328e2 606 "%s%s - ldap_bind() returned -1", host, porttext);
7c7ad977
PH
607 goto RETURN_ERROR;
608 }
0756eb3c 609
7c7ad977
PH
610 if ((rc = ldap_result( lcp->ld, msgid, 1, timeoutptr, &result )) <= 0)
611 {
612 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
8e669ac1 613 "%s%s - LDAP error: %s", host, porttext,
7c7ad977
PH
614 rc == -1 ? "result retrieval failed" : "timeout" );
615 result = NULL;
616 goto RETURN_ERROR;
617 }
618
619 rc = ldap_result2error( lcp->ld, result, 0 );
620
621 /* Invalid credentials when just checking credentials returns FAIL. This
622 stops any further servers being tried. */
0756eb3c 623
7c7ad977
PH
624 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
625 {
626 DEBUG(D_lookup)
627 debug_printf("Invalid credentials: ldapauth returns FAIL\n");
628 error_yield = FAIL;
629 goto RETURN_ERROR_NOMSG;
630 }
0756eb3c 631
7c7ad977
PH
632 /* Otherwise we have a problem that doesn't stop further servers from being
633 tried. */
634
635 if (rc != LDAP_SUCCESS)
636 {
0756eb3c
PH
637 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
638 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
639 goto RETURN_ERROR;
640 }
641
642 /* Successful bind */
643
644 lcp->bound = TRUE;
645 lcp->user = (user == NULL)? NULL : string_copy(user);
646 lcp->password = (password == NULL)? NULL : string_copy(password);
7c7ad977
PH
647
648 ldap_msgfree(result);
649 result = NULL;
0756eb3c
PH
650 }
651
652/* If we are just checking credentials, return OK. */
653
654if (search_type == SEARCH_LDAP_AUTH)
655 {
656 DEBUG(D_lookup) debug_printf("Bind succeeded: ldapauth returns OK\n");
657 goto RETURN_OK;
658 }
659
660/* Before doing the search, set the time and size limits (if given). Here again
661the different implementations of LDAP have chosen to do things differently. */
662
663#if defined(LDAP_OPT_SIZELIMIT)
664ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
665ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
666#else
667lcp->ld->ld_sizelimit = sizelimit;
668lcp->ld->ld_timelimit = timelimit;
669#endif
670
671/* Similarly for dereferencing aliases. Don't know if this is possible on
672an LDAP library without LDAP_OPT_DEREF. */
673
674#if defined(LDAP_OPT_DEREF)
675ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
676#endif
677
6ec97b1b
PH
678/* Similarly for the referral setting; should the library follow referrals that
679the LDAP server returns? The conditional is just in case someone uses a library
680without it. */
681
682#if defined(LDAP_OPT_REFERRALS)
683ldap_set_option(lcp->ld, LDAP_OPT_REFERRALS, referrals);
684#endif
685
0756eb3c
PH
686/* Start the search on the server. */
687
688DEBUG(D_lookup) debug_printf("Start search\n");
689
690msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
691 ludp->lud_attrs, 0);
692
693if (msgid == -1)
694 {
3ca0ba97
PH
695 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
696 int err;
697 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
8e669ac1 698 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
3ca0ba97 699 ldap_err2string(err));
8e669ac1
PH
700
701 #else
3ca0ba97
PH
702 *errmsg = string_sprintf("ldap_search failed");
703 #endif
8e669ac1 704
0756eb3c
PH
705 goto RETURN_ERROR;
706 }
707
708/* Loop to pick up results as they come in, setting a timeout if one was
709given. */
710
0756eb3c
PH
711while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
712 LDAP_RES_SEARCH_ENTRY)
713 {
714 LDAPMessage *e;
715
716 DEBUG(D_lookup) debug_printf("ldap_result loop\n");
717
718 for(e = ldap_first_entry(lcp->ld, result);
719 e != NULL;
720 e = ldap_next_entry(lcp->ld, e))
721 {
722 uschar *new_dn;
723 BOOL insert_space = FALSE;
724
725 DEBUG(D_lookup) debug_printf("LDAP entry loop\n");
726
727 rescount++; /* Count results */
728
729 /* Results for multiple entries values are separated by newlines. */
730
731 if (data != NULL) data = string_cat(data, &size, &ptr, US"\n", 1);
732
733 /* Get the DN from the last result. */
734
735 new_dn = US ldap_get_dn(lcp->ld, e);
736 if (new_dn != NULL)
737 {
738 if (dn != NULL)
739 {
740 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
741 ldap_memfree(dn);
742 #else /* OPENLDAP 1, UMich, Solaris */
743 free(dn);
744 #endif
745 }
746 /* Save for later */
747 dn = new_dn;
748 }
749
750 /* If the data we want is actually the DN rather than any attribute values,
751 (an "ldapdn" search) add it to the data string. If there are multiple
752 entries, the DNs will be concatenated, but we test for this case below, as
753 for SEARCH_LDAP_SINGLE, and give an error. */
754
755 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
756 { /* condition, because of the else */
757 if (new_dn != NULL) /* below, that's for the first only */
758 {
759 data = string_cat(data, &size, &ptr, new_dn, Ustrlen(new_dn));
760 data[ptr] = 0;
761 attribute_found = TRUE;
762 }
763 }
764
765 /* Otherwise, loop through the entry, grabbing attribute values. If there's
766 only one attribute being retrieved, no attribute name is given, and the
767 result is not quoted. Multiple values are separated by (comma, space).
768 If more than one attribute is being retrieved, the data is given as a
769 sequence of name=value pairs, with the value always in quotes. If there are
770 multiple values, they are given within the quotes, comma separated. */
771
772 else for (attr = US ldap_first_attribute(lcp->ld, e, &ber);
773 attr != NULL;
774 attr = US ldap_next_attribute(lcp->ld, e, ber))
775 {
776 if (attr[0] != 0)
777 {
778 /* Get array of values for this attribute. */
779
780 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr))
781 != NULL)
782 {
783 if (attr_count != 1)
784 {
785 if (insert_space)
786 data = string_cat(data, &size, &ptr, US" ", 1);
787 else
788 insert_space = TRUE;
789 data = string_cat(data, &size, &ptr, attr, Ustrlen(attr));
790 data = string_cat(data, &size, &ptr, US"=\"", 2);
791 }
792
793 while (*values != NULL)
794 {
795 uschar *value = *values;
796 int len = Ustrlen(value);
797
798 DEBUG(D_lookup) debug_printf("LDAP attr loop %s:%s\n", attr, value);
799
800 if (values != firstval)
7bba24eb 801 data = string_cat(data, &size, &ptr, US",", 1);
0756eb3c
PH
802
803 /* For multiple attributes, the data is in quotes. We must escape
7bba24eb 804 internal quotes, backslashes, newlines, and must double commas. */
0756eb3c
PH
805
806 if (attr_count != 1)
807 {
808 int j;
809 for (j = 0; j < len; j++)
810 {
811 if (value[j] == '\n')
812 data = string_cat(data, &size, &ptr, US"\\n", 2);
7bba24eb
JH
813 else if (value[j] == ',')
814 data = string_cat(data, &size, &ptr, US",,", 2);
0756eb3c
PH
815 else
816 {
817 if (value[j] == '\"' || value[j] == '\\')
818 data = string_cat(data, &size, &ptr, US"\\", 1);
819 data = string_cat(data, &size, &ptr, value+j, 1);
820 }
821 }
822 }
823
7bba24eb
JH
824 /* For single attributes, just double commas */
825
826 else
827 {
828 int j;
829 for (j = 0; j < len; j++)
830 {
831 if (value[j] == ',')
832 data = string_cat(data, &size, &ptr, US",,", 2);
833 else
834 data = string_cat(data, &size, &ptr, value+j, 1);
835 }
836 }
0756eb3c 837
0756eb3c
PH
838
839 /* Move on to the next value */
840
841 values++;
842 attribute_found = TRUE;
843 }
844
845 /* Closing quote at the end of the data for a named attribute. */
846
847 if (attr_count != 1)
848 data = string_cat(data, &size, &ptr, US"\"", 1);
849
850 /* Free the values */
851
852 ldap_value_free(CSS firstval);
853 }
854 }
855
856 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
857
858 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
859 to be freed. UMich LDAP stores them in static storage and does not require
860 this. */
861
862 ldap_memfree(attr);
863 #endif
864 } /* End "for" loop for extracting attributes from an entry */
865 } /* End "for" loop for extracting entries from a result */
866
867 /* Free the result */
868
869 ldap_msgfree(result);
870 result = NULL;
871 } /* End "while" loop for multiple results */
872
873/* Terminate the dynamic string that we have built and reclaim unused store */
874
875if (data != NULL)
876 {
877 data[ptr] = 0;
878 store_reset(data + ptr + 1);
879 }
880
881/* Copy the last dn into eldap_dn */
882
883if (dn != NULL)
884 {
885 eldap_dn = string_copy(dn);
886 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
887 ldap_memfree(dn);
888 #else /* OPENLDAP 1, UMich, Solaris */
889 free(dn);
890 #endif
891 }
892
893DEBUG(D_lookup) debug_printf("search ended by ldap_result yielding %d\n",rc);
894
895if (rc == 0)
896 {
897 *errmsg = US"ldap_result timed out";
898 goto RETURN_ERROR;
899 }
900
901/* A return code of -1 seems to mean "ldap_result failed internally or couldn't
902provide you with a message". Other error states seem to exist where
903ldap_result() didn't give us any message from the server at all, leaving result
904set to NULL. Apparently, "the error parameters of the LDAP session handle will
905be set accordingly". That's the best we can do to retrieve an error status; we
906can't use functions like ldap_result2error because they parse a message from
907the server, which we didn't get.
908
909Annoyingly, the different implementations of LDAP have gone for different
910methods of handling error codes and generating error messages. */
911
912if (rc == -1 || result == NULL)
913 {
914 int err;
915 DEBUG(D_lookup) debug_printf("ldap_result failed\n");
916
917 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
918 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
919 *errmsg = string_sprintf("ldap_result failed: %d, %s",
920 err, ldap_err2string(err));
921
922 #elif defined LDAP_LIB_NETSCAPE
923 /* Dubious (surely 'matched' is spurious here?) */
924 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
925 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
926
927 #else /* UMich LDAP aka OpenLDAP 1.x */
928 *errmsg = string_sprintf("ldap_result failed: %d, %s",
929 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
930 #endif
931
932 goto RETURN_ERROR;
933 }
934
935/* A return code that isn't -1 doesn't necessarily mean there were no problems
8e669ac1
PH
936with the search. The message must be an LDAP_RES_SEARCH_RESULT or
937LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
938of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
3295e65b
PH
939we don't provide that functionality when we can't. :-) */
940
8e669ac1 941if (rc != LDAP_RES_SEARCH_RESULT
3295e65b
PH
942#ifdef LDAP_RES_SEARCH_REFERENCE
943 && rc != LDAP_RES_SEARCH_REFERENCE
8e669ac1 944#endif
3295e65b 945 )
0756eb3c
PH
946 {
947 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
948 goto RETURN_ERROR;
949 }
950
951/* We have a result message from the server. This doesn't yet mean all is well.
952We need to parse the message to find out exactly what's happened. */
953
d38f8232
PH
954#if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
955 ldap_rc = rc;
8e669ac1 956 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
d38f8232
PH
957 CSS &error2, NULL, NULL, 0);
958 DEBUG(D_lookup) debug_printf("ldap_parse_result: %d\n", ldap_parse_rc);
8e669ac1 959 if (ldap_parse_rc < 0 &&
3295e65b 960 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
8e669ac1 961 #ifdef LDAP_RES_SEARCH_REFERENCE
3295e65b 962 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
8e669ac1 963 #endif
3295e65b 964 ))
0756eb3c 965 {
d38f8232 966 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
0756eb3c
PH
967 goto RETURN_ERROR;
968 }
969 error1 = US ldap_err2string(rc);
970
971#elif defined LDAP_LIB_NETSCAPE
972 /* Dubious (it doesn't reference 'result' at all!) */
973 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
974
975#else /* UMich LDAP aka OpenLDAP 1.x */
976 rc = ldap_result2error(lcp->ld, result, 0);
977 error1 = ldap_err2string(rc);
978 error2 = lcp->ld->ld_error;
979 matched = lcp->ld->ld_matched;
980#endif
981
982/* Process the status as follows:
983
984 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
985 truncated result list.
986
21eb6e72
PH
987 (2) If we get LDAP_RES_SEARCH_REFERENCE, also just carry on. This was a
988 submitted patch that is reported to "do the right thing" with Solaris
989 LDAP libraries. (The problem it addresses apparently does not occur with
990 Open LDAP.)
991
992 (3) The range of errors defined by LDAP_NAME_ERROR generally mean "that
0756eb3c
PH
993 object does not, or cannot, exist in the database". For those cases we
994 fail the lookup.
995
21eb6e72 996 (4) All other non-successes here are treated as some kind of problem with
0756eb3c
PH
997 the lookup, so return DEFER (which is the default in error_yield).
998*/
999
1000DEBUG(D_lookup) debug_printf("ldap_parse_result yielded %d: %s\n",
1001 rc, ldap_err2string(rc));
1002
21eb6e72
PH
1003if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED
1004 #ifdef LDAP_RES_SEARCH_REFERENCE
1005 && rc != LDAP_RES_SEARCH_REFERENCE
1006 #endif
1007 )
0756eb3c
PH
1008 {
1009 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
1010 rc,
1011 (error1 != NULL)? error1 : US"",
1012 (error2 != NULL && error2[0] != 0)? US"/" : US"",
1013 (error2 != NULL)? error2 : US"",
1014 (matched != NULL && matched[0] != 0)? US"/" : US"",
1015 (matched != NULL)? matched : US"");
1016
1017 #if defined LDAP_NAME_ERROR
1018 if (LDAP_NAME_ERROR(rc))
1019 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
1020 if (NAME_ERROR(rc))
1021 #else
1022 if (rc == LDAP_NO_SUCH_OBJECT)
1023 #endif
1024
1025 {
1026 DEBUG(D_lookup) debug_printf("lookup failure forced\n");
1027 error_yield = FAIL;
1028 }
1029 goto RETURN_ERROR;
1030 }
1031
1032/* The search succeeded. Check if we have too many results */
1033
1034if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
1035 {
1036 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
1037 "(filter not specific enough?)", rescount);
1038 goto RETURN_ERROR_BREAK;
1039 }
1040
1041/* Check if we have too few (zero) entries */
1042
1043if (rescount < 1)
1044 {
1045 *errmsg = string_sprintf("LDAP search: no results");
1046 error_yield = FAIL;
1047 goto RETURN_ERROR_BREAK;
1048 }
1049
1050/* If an entry was found, but it had no attributes, we behave as if no entries
1051were found, that is, the lookup failed. */
1052
1053if (!attribute_found)
1054 {
1055 *errmsg = US"LDAP search: found no attributes";
1056 error_yield = FAIL;
1057 goto RETURN_ERROR;
1058 }
1059
1060/* Otherwise, it's all worked */
1061
1062DEBUG(D_lookup) debug_printf("LDAP search: returning: %s\n", data);
1063*res = data;
1064
1065RETURN_OK:
1066if (result != NULL) ldap_msgfree(result);
1067ldap_free_urldesc(ludp);
1068return OK;
1069
1070/* Error returns */
1071
1072RETURN_ERROR_BREAK:
1073*defer_break = TRUE;
1074
1075RETURN_ERROR:
1076DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1077
1078RETURN_ERROR_NOMSG:
1079if (result != NULL) ldap_msgfree(result);
1080if (ludp != NULL) ldap_free_urldesc(ludp);
1081
1082#if defined LDAP_LIB_OPENLDAP2
1083 if (error2 != NULL) ldap_memfree(error2);
1084 if (matched != NULL) ldap_memfree(matched);
1085#endif
1086
1087return error_yield;
1088}
1089
1090
1091
1092/*************************************************
1093* Internal search control function *
1094*************************************************/
1095
1096/* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
1097and eldapm_find() with a difference in the "search_type" argument. It controls
1098calls to perform_ldap_search() which actually does the work. We call that
1099repeatedly for certain types of defer in the case when the URL contains no host
1100name and eldap_default_servers is set to a list of servers to try. This gives
1101more control than just passing over a list of hosts to ldap_open() because it
1102handles other kinds of defer as well as just a failure to open. Note that the
1103URL is defined to contain either zero or one "hostport" only.
1104
1105Parameter data in addition to the URL can be passed as preceding text in the
1106string, as items of the form XXX=yyy. The URL itself can be detected because it
1107must begin "ldapx://", where x is empty, s, or i.
1108
1109Arguments:
1110 ldap_url the URL to be looked up, optionally preceded by other parameter
1111 settings
1112 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
1113 SEARCH_LDAP_SINGLE allows values from one entry only
1114 SEARCH_LDAP_DN gets the DN from one entry
1115 res set to point at the result
1116 errmsg set to point a message if result is not OK
1117
1118Returns: OK or FAIL or DEFER
1119*/
1120
1121static int
1122control_ldap_search(uschar *ldap_url, int search_type, uschar **res,
1123 uschar **errmsg)
1124{
1125BOOL defer_break = FALSE;
1126int timelimit = LDAP_NO_LIMIT;
1127int sizelimit = LDAP_NO_LIMIT;
7c7ad977 1128int tcplimit = 0;
0756eb3c 1129int sep = 0;
6ec97b1b
PH
1130int dereference = LDAP_DEREF_NEVER;
1131void* referrals = LDAP_OPT_ON;
0756eb3c
PH
1132uschar *url = ldap_url;
1133uschar *p;
1134uschar *user = NULL;
1135uschar *password = NULL;
deae092e 1136uschar *local_servers = NULL;
0756eb3c
PH
1137uschar *server, *list;
1138uschar buffer[512];
1139
1140while (isspace(*url)) url++;
1141
1142/* Until the string begins "ldap", search for the other parameter settings that
1143are recognized. They are of the form NAME=VALUE, with the value being
1144optionally double-quoted. There must still be a space after it, however. No
1145NAME has the value "ldap". */
1146
1147while (strncmpic(url, US"ldap", 4) != 0)
1148 {
1149 uschar *name = url;
1150 while (*url != 0 && *url != '=') url++;
1151 if (*url == '=')
1152 {
1153 int namelen;
1154 uschar *value;
1155 namelen = ++url - name;
1156 value = string_dequote(&url);
1157 if (isspace(*url))
1158 {
1159 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1160 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1161 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1162 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
7c7ad977
PH
1163 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1164 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
deae092e 1165 else if (strncmpic(name, US"SERVERS=", namelen) == 0) local_servers = value;
0756eb3c
PH
1166
1167 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1168
1169 #ifdef LDAP_OPT_DEREF
1170 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1171 {
1172 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1173 else if (strcmpic(value, US"searching") == 0)
1174 dereference = LDAP_DEREF_SEARCHING;
1175 else if (strcmpic(value, US"finding") == 0)
1176 dereference = LDAP_DEREF_FINDING;
1177 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1178 }
1179 #else
1180 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1181 {
1182 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1183 "library - cannot use \"dereference\"");
1184 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1185 return DEFER;
1186 }
6ec97b1b 1187 #endif
0756eb3c 1188
6ec97b1b
PH
1189 #ifdef LDAP_OPT_REFERRALS
1190 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1191 {
1192 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1193 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1194 else
1195 {
1196 *errmsg = string_sprintf("LDAP option REFERRALS is not \"follow\" "
1197 "or \"nofollow\"");
1198 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1199 return DEFER;
1200 }
1201 }
1202 #else
1203 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1204 {
1205 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1206 "library - cannot use \"referrals\"");
1207 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
1208 return DEFER;
1209 }
0756eb3c
PH
1210 #endif
1211
1212 else
1213 {
1214 *errmsg =
1215 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1216 namelen, name);
1217 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1218 return DEFER;
1219 }
1220 while (isspace(*url)) url++;
1221 continue;
1222 }
1223 }
1224 *errmsg = US"malformed parameter setting precedes LDAP URL";
1225 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1226 return DEFER;
1227 }
1228
1229/* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1230but it seems that not all behave like this. The DN for the user is often the
1231result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1232that is needed when the DN is used as a base DN in a query. Sigh. This is all
1233far too complicated. */
1234
1235if (user != NULL)
1236 {
1237 uschar *s;
1238 uschar *t = user;
1239 for (s = user; *s != 0; s++)
1240 {
1241 int c, d;
1242 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1243 {
1244 c = tolower(c);
1245 d = tolower(d);
1246 *t++ =
1247 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1248 ((d >= 'a')? (10 + d - 'a') : d - '0');
1249 s += 2;
1250 }
1251 else *t++ = *s;
1252 }
1253 *t = 0;
1254 }
1255
1256DEBUG(D_lookup)
1257 debug_printf("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
6ec97b1b
PH
1258 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1259 tcplimit, dereference, (referrals == LDAP_OPT_ON)? "on" : "off");
0756eb3c
PH
1260
1261/* If the request is just to check authentication, some credentials must
1262be given. The password must not be empty because LDAP binds with an empty
1263password are considered anonymous, and will succeed on most installations. */
1264
1265if (search_type == SEARCH_LDAP_AUTH)
1266 {
1267 if (user == NULL || password == NULL)
1268 {
1269 *errmsg = US"ldapauth lookups must specify the username and password";
1270 return DEFER;
1271 }
1272 if (password[0] == 0)
1273 {
1274 DEBUG(D_lookup) debug_printf("Empty password: ldapauth returns FAIL\n");
1275 return FAIL;
1276 }
1277 }
1278
1279/* Check for valid ldap url starters */
1280
1281p = url + 4;
1282if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1283if (Ustrncmp(p, "://", 3) != 0)
1284 {
1285 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1286 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1287 DEBUG(D_lookup) debug_printf("LDAP query error: %s\n", *errmsg);
1288 return DEFER;
1289 }
1290
1291/* No default servers, or URL contains a server name: just one attempt */
1292
deae092e 1293if ((eldap_default_servers == NULL && local_servers == NULL) || p[3] != '/')
0756eb3c
PH
1294 {
1295 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
6ec97b1b
PH
1296 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1297 referrals);
0756eb3c
PH
1298 }
1299
deae092e
HS
1300/* Loop through the default servers until OK or FAIL. Use local_servers list
1301 * if defined in the lookup, otherwise use the global default list */
1302list = (local_servers == NULL) ? eldap_default_servers : local_servers;
0756eb3c
PH
1303while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
1304 {
1305 int rc;
1306 int port = 0;
1307 uschar *colon = Ustrchr(server, ':');
1308 if (colon != NULL)
1309 {
1310 *colon = 0;
1311 port = Uatoi(colon+1);
1312 }
1313 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
6ec97b1b
PH
1314 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1315 referrals);
0756eb3c
PH
1316 if (rc != DEFER || defer_break) return rc;
1317 }
1318
1319return DEFER;
1320}
1321
1322
1323
1324/*************************************************
1325* Find entry point *
1326*************************************************/
1327
1328/* See local README for interface description. The different kinds of search
1329are handled by a common function, with a flag to differentiate between them.
1330The handle and filename arguments are not used. */
1331
e6d225ae 1332static int
0756eb3c
PH
1333eldap_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1334 uschar **result, uschar **errmsg, BOOL *do_cache)
1335{
1336/* Keep picky compilers happy */
1337do_cache = do_cache;
1338return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1339}
1340
e6d225ae 1341static int
0756eb3c
PH
1342eldapm_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1343 uschar **result, uschar **errmsg, BOOL *do_cache)
1344{
1345/* Keep picky compilers happy */
1346do_cache = do_cache;
1347return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1348}
1349
e6d225ae 1350static int
0756eb3c
PH
1351eldapdn_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1352 uschar **result, uschar **errmsg, BOOL *do_cache)
1353{
1354/* Keep picky compilers happy */
1355do_cache = do_cache;
1356return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1357}
1358
1359int
1360eldapauth_find(void *handle, uschar *filename, uschar *ldap_url, int length,
1361 uschar **result, uschar **errmsg, BOOL *do_cache)
1362{
1363/* Keep picky compilers happy */
1364do_cache = do_cache;
1365return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1366}
1367
1368
1369
1370/*************************************************
1371* Open entry point *
1372*************************************************/
1373
1374/* See local README for interface description. */
1375
e6d225ae 1376static void *
0756eb3c
PH
1377eldap_open(uschar *filename, uschar **errmsg)
1378{
1379return (void *)(1); /* Just return something non-null */
1380}
1381
1382
1383
1384/*************************************************
1385* Tidy entry point *
1386*************************************************/
1387
1388/* See local README for interface description.
1389Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1390
e6d225ae 1391static void
0756eb3c
PH
1392eldap_tidy(void)
1393{
1394LDAP_CONNECTION *lcp = NULL;
1395eldap_dn = NULL;
1396
1397while ((lcp = ldap_connections) != NULL)
1398 {
1399 DEBUG(D_lookup) debug_printf("unbind LDAP connection to %s:%d\n", lcp->host,
1400 lcp->port);
ff2c417d
TL
1401 if(lcp->bound == TRUE)
1402 ldap_unbind(lcp->ld);
0756eb3c
PH
1403 ldap_connections = lcp->next;
1404 }
1405}
1406
1407
1408
1409/*************************************************
1410* Quote entry point *
1411*************************************************/
1412
1413/* LDAP quoting is unbelievably messy. For a start, two different levels of
1414quoting have to be done: LDAP quoting, and URL quoting. The current
1415specification is the result of a suggestion by Brian Candler. It recognizes
1416two separate cases:
1417
1418(1) For text that appears in a search filter, the following escapes are
1419 required (see RFC 2254):
1420
1421 * -> \2A
1422 ( -> \28
1423 ) -> \29
1424 \ -> \5C
1425 NULL -> \00
1426
1427 Then the entire filter text must be URL-escaped. This kind of quoting is
1428 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1429 in the input string, because that's a terminator.
1430
1431(2) For a DN that is part of a URL (i.e. the base DN), the characters
1432
1433 , + " \ < > ;
1434
1435 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1436 must be escaped, as must a leading #. Then the string must be URL-quoted.
1437 This type of quoting is implemented by ${quote_ldap_dn:....}.
1438
1439For URL quoting, the only characters that need not be quoted are the
1440alphamerics and
1441
1442 ! $ ' ( ) * + - . _
1443
1444All the others must be hexified and preceded by %. This includes the
1445backslashes used for LDAP quoting.
1446
1447For a DN that is given in the USER parameter for authentication, we need the
1448same initial quoting as (2) but in this case, the result must NOT be
1449URL-escaped, because it isn't a URL. The way this is handled is by
1450de-URL-quoting the text when processing the USER parameter in
1451control_ldap_search() above. That means that the same quote operator can be
1452used. This has the additional advantage that spaces in the DN won't cause
1453parsing problems. For example:
1454
1455 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1456
1457should be safe if there are spaces in $1.
1458
1459
1460Arguments:
1461 s the string to be quoted
1462 opt additional option text or NULL if none
1463 only "dn" is recognized
1464
1465Returns: the processed string or NULL for a bad option
1466*/
1467
1468
1469
1470/* The characters in this string, together with alphanumerics, never need
1471quoting in any way. */
1472
1473#define ALWAYS_LITERAL "!$'-._"
1474
1475/* The special characters in this string do not need to be URL-quoted. The set
1476is a bit larger than the general literals. */
1477
1478#define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1479
1480/* The following macros define the characters that are quoted by quote_ldap and
1481quote_ldap_dn, respectively. */
1482
1483#define LDAP_QUOTE "*()\\"
1484#define LDAP_DN_QUOTE ",+\"\\<>;"
1485
1486
1487
e6d225ae 1488static uschar *
0756eb3c
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1489eldap_quote(uschar *s, uschar *opt)
1490{
1491register int c;
1492int count = 0;
1493int len = 0;
1494BOOL dn = FALSE;
1495uschar *t = s;
1496uschar *quoted;
1497
1498/* Test for a DN quotation. */
1499
1500if (opt != NULL)
1501 {
1502 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1503 dn = TRUE;
1504 }
1505
1506/* Compute how much extra store we need for the string. This doesn't have to be
1507exact as long as it isn't an underestimate. The worst case is the addition of 5
1508extra bytes for a single character. This occurs for certain characters in DNs,
1509where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1510possibly escaped character. The really fast way would be just to test for
1511non-alphanumerics, but it is probably better to spot a few others that are
1512never escaped, because if there are no specials at all, we can avoid copying
1513the string. */
1514
1515while ((c = *t++) != 0)
1516 {
1517 len++;
1518 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1519 }
1520if (count == 0) return s;
1521
1522/* Get sufficient store to hold the quoted string */
1523
1524t = quoted = store_get(len + count + 1);
1525
1526/* Handle plain quote_ldap */
1527
1528if (!dn)
1529 {
1530 while ((c = *s++) != 0)
1531 {
1532 if (!isalnum(c))
1533 {
1534 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1535 {
1536 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1537 t += 5;
1538 continue;
1539 }
1540 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1541 {
1542 sprintf(CS t, "%%%02X", c);
1543 t += 3;
1544 continue;
1545 }
1546 }
1547 *t++ = c; /* unquoted character */
1548 }
1549 }
1550
1551/* Handle quote_ldap_dn */
1552
1553else
1554 {
1555 uschar *ss = s + len;
1556
1557 /* Find the last char before any trailing spaces */
1558
1559 while (ss > s && ss[-1] == ' ') ss--;
1560
1561 /* Quote leading spaces and sharps */
1562
1563 for (; s < ss; s++)
1564 {
1565 if (*s != ' ' && *s != '#') break;
1566 sprintf(CS t, "%%5C%%%02X", *s);
1567 t += 6;
1568 }
1569
1570 /* Handle the rest of the string, up to the trailing spaces */
1571
1572 while (s < ss)
1573 {
1574 c = *s++;
1575 if (!isalnum(c))
1576 {
1577 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1578 {
1579 Ustrncpy(t, "%5C", 3); /* insert \ where needed */
1580 t += 3; /* fall through to check URL */
1581 }
1582 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1583 {
1584 sprintf(CS t, "%%%02X", c);
1585 t += 3;
1586 continue;
1587 }
1588 }
1589 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1590 }
1591
1592 /* Handle the trailing spaces */
1593
1594 while (*ss++ != 0)
1595 {
1596 Ustrncpy(t, "%5C%20", 6);
1597 t += 6;
1598 }
1599 }
1600
1601/* Terminate the new string and return */
1602
1603*t = 0;
1604return quoted;
1605}
1606
6545de78
PP
1607
1608
1609/*************************************************
1610* Version reporting entry point *
1611*************************************************/
1612
1613/* See local README for interface description. */
1614
1615#include "../version.h"
1616
1617void
1618ldap_version_report(FILE *f)
1619{
1620#ifdef DYNLOOKUP
1621fprintf(f, "Library version: LDAP: Exim version %s\n", EXIM_VERSION_STR);
1622#endif
1623}
1624
1625
e6d225ae
DW
1626static lookup_info ldap_lookup_info = {
1627 US"ldap", /* lookup name */
1628 lookup_querystyle, /* query-style lookup */
1629 eldap_open, /* open function */
1630 NULL, /* check function */
1631 eldap_find, /* find function */
1632 NULL, /* no close function */
1633 eldap_tidy, /* tidy function */
6545de78
PP
1634 eldap_quote, /* quoting function */
1635 ldap_version_report /* version reporting */
e6d225ae
DW
1636};
1637
1638static lookup_info ldapdn_lookup_info = {
1639 US"ldapdn", /* lookup name */
1640 lookup_querystyle, /* query-style lookup */
1641 eldap_open, /* sic */ /* open function */
1642 NULL, /* check function */
1643 eldapdn_find, /* find function */
1644 NULL, /* no close function */
1645 eldap_tidy, /* sic */ /* tidy function */
6545de78
PP
1646 eldap_quote, /* sic */ /* quoting function */
1647 NULL /* no version reporting (redundant) */
e6d225ae
DW
1648};
1649
1650static lookup_info ldapm_lookup_info = {
1651 US"ldapm", /* lookup name */
1652 lookup_querystyle, /* query-style lookup */
1653 eldap_open, /* sic */ /* open function */
1654 NULL, /* check function */
1655 eldapm_find, /* find function */
1656 NULL, /* no close function */
1657 eldap_tidy, /* sic */ /* tidy function */
6545de78
PP
1658 eldap_quote, /* sic */ /* quoting function */
1659 NULL /* no version reporting (redundant) */
e6d225ae
DW
1660};
1661
1662#ifdef DYNLOOKUP
1663#define ldap_lookup_module_info _lookup_module_info
1664#endif
1665
1666static lookup_info *_lookup_list[] = { &ldap_lookup_info, &ldapdn_lookup_info, &ldapm_lookup_info };
1667lookup_module_info ldap_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
0756eb3c
PH
1668
1669/* End of lookups/ldap.c */