C99 initialisers
[exim.git] / src / src / lookups / ldap.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
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 contributions 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 gstring * data = NULL;
147 uschar *dn = NULL;
148 uschar *host;
149 uschar **values;
150 uschar **firstval;
151 uschar porttext[16];
152
153 uschar *error1 = NULL; /* string representation of errcode (static) */
154 uschar *error2 = NULL; /* error message from the server */
155 uschar *matched = NULL; /* partially matched DN */
156
157 int attrs_requested = 0;
158 int error_yield = DEFER;
159 int msgid;
160 int rc, ldap_rc, ldap_parse_rc;
161 int port;
162 int rescount = 0;
163 BOOL attribute_found = FALSE;
164 BOOL ldapi = FALSE;
165
166 DEBUG(D_lookup) debug_printf_indent("perform_ldap_search:"
167 " ldap%s URL = \"%s\" server=%s port=%d "
168 "sizelimit=%d timelimit=%d tcplimit=%d\n",
169 search_type == SEARCH_LDAP_MULTIPLE ? "m" :
170 search_type == SEARCH_LDAP_DN ? "dn" :
171 search_type == SEARCH_LDAP_AUTH ? "auth" : "",
172 ldap_url, server, s_port, sizelimit, timelimit, tcplimit);
173
174 /* Check if LDAP thinks the URL is a valid LDAP URL. We assume that if the LDAP
175 library that is in use doesn't recognize, say, "ldapi", it will barf here. */
176
177 if (!ldap_is_ldap_url(CS ldap_url))
178 {
179 *errmsg = string_sprintf("ldap_is_ldap_url: not an LDAP url \"%s\"\n",
180 ldap_url);
181 goto RETURN_ERROR_BREAK;
182 }
183
184 /* Parse the URL */
185
186 if ((rc = ldap_url_parse(CS ldap_url, &ludp)) != 0)
187 {
188 *errmsg = string_sprintf("ldap_url_parse: (error %d) parsing \"%s\"\n", rc,
189 ldap_url);
190 goto RETURN_ERROR_BREAK;
191 }
192
193 /* If the host name is empty, take it from the separate argument, if one is
194 given. OpenLDAP 2.0.6 sets an unset hostname to "" rather than empty, but
195 expects NULL later in ldap_init() to mean "default", annoyingly. In OpenLDAP
196 2.0.11 this has changed (it uses NULL). */
197
198 if ((!ludp->lud_host || !ludp->lud_host[0]) && server)
199 {
200 host = server;
201 port = s_port;
202 }
203 else
204 {
205 host = US ludp->lud_host;
206 if (host && !host[0]) host = NULL;
207 port = ludp->lud_port;
208 }
209
210 DEBUG(D_lookup) debug_printf_indent("after ldap_url_parse: host=%s port=%d\n",
211 host, port);
212
213 if (port == 0) port = LDAP_PORT; /* Default if none given */
214 sprintf(CS porttext, ":%d", port); /* For messages */
215
216 /* If the "host name" is actually a path, we are going to connect using a Unix
217 socket, regardless of whether "ldapi" was actually specified or not. This means
218 that a Unix socket can be declared in eldap_default_servers, and "traditional"
219 LDAP queries using just "ldap" can be used ("ldaps" is similarly overridden).
220 The path may start with "/" or it may already be escaped as "%2F" if it was
221 actually declared that way in eldap_default_servers. (I did it that way the
222 first time.) If the host name is not a path, the use of "ldapi" causes an
223 error, except in the default case. (But lud_scheme doesn't seem to exist in
224 older libraries.) */
225
226 if (host)
227 {
228 if ((host[0] == '/' || Ustrncmp(host, "%2F", 3) == 0))
229 {
230 ldapi = TRUE;
231 porttext[0] = 0; /* Remove port from messages */
232 }
233
234 #if defined LDAP_LIB_OPENLDAP2
235 else if (strncmp(ludp->lud_scheme, "ldapi", 5) == 0)
236 {
237 *errmsg = string_sprintf("ldapi requires an absolute path (\"%s\" given)",
238 host);
239 goto RETURN_ERROR;
240 }
241 #endif
242 }
243
244 /* Count the attributes; we need this later to tell us how to format results */
245
246 for (uschar ** attrp = USS ludp->lud_attrs; attrp && *attrp; attrp++)
247 attrs_requested++;
248
249 /* See if we can find a cached connection to this host. The port is not
250 relevant for ldapi. The host name pointer is set to NULL if no host was given
251 (implying the library default), rather than to the empty string. Note that in
252 this case, there is no difference between ldap and ldapi. */
253
254 for (lcp = ldap_connections; lcp; lcp = lcp->next)
255 {
256 if ((host == NULL) != (lcp->host == NULL) ||
257 (host != NULL && strcmpic(lcp->host, host) != 0))
258 continue;
259 if (ldapi || port == lcp->port) break;
260 }
261
262 /* Use this network timeout in any requests. */
263
264 if (tcplimit > 0)
265 {
266 timeout.tv_sec = tcplimit;
267 timeout.tv_usec = 0;
268 timeoutptr = &timeout;
269 }
270
271 /* If no cached connection found, we must open a connection to the server. If
272 the server name is actually an absolute path, we set ldapi=TRUE above. This
273 requests connection via a Unix socket. However, as far as I know, only OpenLDAP
274 supports the use of sockets, and the use of ldap_initialize(). */
275
276 if (!lcp)
277 {
278 LDAP *ld;
279
280 #ifdef LDAP_OPT_X_TLS_NEWCTX
281 int am_server = 0;
282 LDAP *ldsetctx;
283 #else
284 LDAP *ldsetctx = NULL;
285 #endif
286
287
288 /* --------------------------- OpenLDAP ------------------------ */
289
290 /* There seems to be a preference under OpenLDAP for ldap_initialize()
291 instead of ldap_init(), though I have as yet been unable to find
292 documentation that says this. (OpenLDAP documentation is sparse to
293 non-existent). So we handle OpenLDAP differently here. Also, support for
294 ldapi seems to be OpenLDAP-only at present. */
295
296 #ifdef LDAP_LIB_OPENLDAP2
297
298 /* We now need an empty string for the default host. Get some store in which
299 to build a URL for ldap_initialize(). In the ldapi case, it can't be bigger
300 than (9 + 3*Ustrlen(shost)), whereas in the other cases it can't be bigger
301 than the host name + "ldaps:///" plus : and a port number, say 20 + the
302 length of the host name. What we get should accommodate both, easily. */
303
304 uschar * shost = host ? host : US"";
305 rmark reset_point = store_mark();
306 gstring * g;
307
308 /* Handle connection via Unix socket ("ldapi"). We build a basic LDAP URI to
309 contain the path name, with slashes escaped as %2F. */
310
311 if (ldapi)
312 {
313 g = string_catn(NULL, US"ldapi://", 8);
314 for (uschar ch; (ch = *shost); shost++)
315 g = ch == '/' ? string_catn(g, US"%2F", 3) : string_catn(g, shost, 1);
316 }
317
318 /* This is not an ldapi call. Just build a URI with the protocol type, host
319 name, and port. */
320
321 else
322 {
323 uschar * init_ptr = Ustrchr(ldap_url, '/');
324 g = string_catn(NULL, ldap_url, init_ptr - ldap_url);
325 g = string_fmt_append(g, "//%s:%d/", shost, port);
326 }
327 string_from_gstring(g);
328
329 /* Call ldap_initialize() and check the result */
330
331 DEBUG(D_lookup) debug_printf_indent("ldap_initialize with URL %s\n", g->s);
332 if ((rc = ldap_initialize(&ld, CS g->s)) != LDAP_SUCCESS)
333 {
334 *errmsg = string_sprintf("ldap_initialize: (error %d) URL \"%s\"\n",
335 rc, g->s);
336 goto RETURN_ERROR;
337 }
338 store_reset(reset_point); /* Might as well save memory when we can */
339
340
341 /* ------------------------- Not OpenLDAP ---------------------- */
342
343 /* For libraries other than OpenLDAP, use ldap_init(). */
344
345 #else /* LDAP_LIB_OPENLDAP2 */
346 ld = ldap_init(CS host, port);
347 #endif /* LDAP_LIB_OPENLDAP2 */
348
349 /* -------------------------------------------------------------- */
350
351
352 /* Handle failure to initialize */
353
354 if (!ld)
355 {
356 *errmsg = string_sprintf("failed to initialize for LDAP server %s%s - %s",
357 host, porttext, strerror(errno));
358 goto RETURN_ERROR;
359 }
360
361 #ifdef LDAP_OPT_X_TLS_NEWCTX
362 ldsetctx = ld;
363 #endif
364
365 /* Set the TCP connect time limit if available. This is something that is
366 in Netscape SDK v4.1; I don't know about other libraries. */
367
368 #ifdef LDAP_X_OPT_CONNECT_TIMEOUT
369 if (tcplimit > 0)
370 {
371 int timeout1000 = tcplimit*1000;
372 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&timeout1000);
373 }
374 else
375 {
376 int notimeout = LDAP_X_IO_TIMEOUT_NO_TIMEOUT;
377 ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, (void *)&notimeout);
378 }
379 #endif
380
381 /* Set the TCP connect timeout. This works with OpenLDAP 2.2.14. */
382
383 #ifdef LDAP_OPT_NETWORK_TIMEOUT
384 if (tcplimit > 0)
385 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, (void *)timeoutptr);
386 #endif
387
388 /* I could not get TLS to work until I set the version to 3. That version
389 seems to be the default nowadays. The RFC is dated 1997, so I would hope
390 that all the LDAP libraries support it. Therefore, if eldap_version hasn't
391 been set, go for v3 if we can. */
392
393 if (eldap_version < 0)
394 {
395 #ifdef LDAP_VERSION3
396 eldap_version = LDAP_VERSION3;
397 #else
398 eldap_version = 2;
399 #endif
400 }
401
402 #ifdef LDAP_OPT_PROTOCOL_VERSION
403 ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, (void *)&eldap_version);
404 #endif
405
406 DEBUG(D_lookup) debug_printf_indent("initialized for LDAP (v%d) server %s%s\n",
407 eldap_version, host, porttext);
408
409 /* If not using ldapi and TLS is available, set appropriate TLS options: hard
410 for "ldaps" and soft otherwise. */
411
412 #ifdef LDAP_OPT_X_TLS
413 if (!ldapi)
414 {
415 int tls_option;
416 # ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
417 if (eldap_require_cert)
418 {
419 tls_option =
420 Ustrcmp(eldap_require_cert, "hard") == 0 ? LDAP_OPT_X_TLS_HARD
421 : Ustrcmp(eldap_require_cert, "demand") == 0 ? LDAP_OPT_X_TLS_DEMAND
422 : Ustrcmp(eldap_require_cert, "allow") == 0 ? LDAP_OPT_X_TLS_ALLOW
423 : Ustrcmp(eldap_require_cert, "try") == 0 ? LDAP_OPT_X_TLS_TRY
424 : LDAP_OPT_X_TLS_NEVER;
425
426 DEBUG(D_lookup) debug_printf_indent(
427 "Require certificate overrides LDAP_OPT_X_TLS option (%d)\n",
428 tls_option);
429 }
430 else
431 # endif /* LDAP_OPT_X_TLS_REQUIRE_CERT */
432 if (strncmp(ludp->lud_scheme, "ldaps", 5) == 0)
433 {
434 tls_option = LDAP_OPT_X_TLS_HARD;
435 DEBUG(D_lookup)
436 debug_printf_indent("LDAP_OPT_X_TLS_HARD set due to ldaps:// URI\n");
437 }
438 else
439 {
440 tls_option = LDAP_OPT_X_TLS_TRY;
441 DEBUG(D_lookup)
442 debug_printf_indent("LDAP_OPT_X_TLS_TRY set due to ldap:// URI\n");
443 }
444 ldap_set_option(ld, LDAP_OPT_X_TLS, (void *)&tls_option);
445 }
446 #endif /* LDAP_OPT_X_TLS */
447
448 #ifdef LDAP_OPT_X_TLS_CACERTFILE
449 if (eldap_ca_cert_file)
450 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CACERTFILE, eldap_ca_cert_file);
451 #endif
452 #ifdef LDAP_OPT_X_TLS_CACERTDIR
453 if (eldap_ca_cert_dir)
454 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CACERTDIR, eldap_ca_cert_dir);
455 #endif
456 #ifdef LDAP_OPT_X_TLS_CERTFILE
457 if (eldap_cert_file)
458 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CERTFILE, eldap_cert_file);
459 #endif
460 #ifdef LDAP_OPT_X_TLS_KEYFILE
461 if (eldap_cert_key)
462 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_KEYFILE, eldap_cert_key);
463 #endif
464 #ifdef LDAP_OPT_X_TLS_CIPHER_SUITE
465 if (eldap_cipher_suite)
466 ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_CIPHER_SUITE, eldap_cipher_suite);
467 #endif
468 #ifdef LDAP_OPT_X_TLS_REQUIRE_CERT
469 if (eldap_require_cert)
470 {
471 int cert_option =
472 Ustrcmp(eldap_require_cert, "hard") == 0 ? LDAP_OPT_X_TLS_HARD
473 : Ustrcmp(eldap_require_cert, "demand") == 0 ? LDAP_OPT_X_TLS_DEMAND
474 : Ustrcmp(eldap_require_cert, "allow") == 0 ? LDAP_OPT_X_TLS_ALLOW
475 : Ustrcmp(eldap_require_cert, "try") == 0 ? LDAP_OPT_X_TLS_TRY
476 : LDAP_OPT_X_TLS_NEVER;
477
478 /* This ldap handle is set at compile time based on client libs. Older
479 * versions want it to be global and newer versions can force a reload
480 * of the TLS context (to reload these settings we are changing from the
481 * default that loaded at instantiation). */
482 rc = ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_REQUIRE_CERT, &cert_option);
483 if (rc)
484 DEBUG(D_lookup)
485 debug_printf_indent("Unable to set TLS require cert_option(%d) globally: %s\n",
486 cert_option, ldap_err2string(rc));
487 }
488 #endif
489 #ifdef LDAP_OPT_X_TLS_NEWCTX
490 if ((rc = ldap_set_option(ldsetctx, LDAP_OPT_X_TLS_NEWCTX, &am_server)))
491 DEBUG(D_lookup)
492 debug_printf_indent("Unable to reload TLS context %d: %s\n",
493 rc, ldap_err2string(rc));
494 #endif
495
496 /* Now add this connection to the chain of cached connections */
497
498 lcp = store_get(sizeof(LDAP_CONNECTION), FALSE);
499 lcp->host = host ? string_copy(host) : NULL;
500 lcp->bound = FALSE;
501 lcp->user = NULL;
502 lcp->password = NULL;
503 lcp->port = port;
504 lcp->ld = ld;
505 lcp->next = ldap_connections;
506 lcp->is_start_tls_called = FALSE;
507 ldap_connections = lcp;
508 }
509
510 /* Found cached connection */
511
512 else
513 DEBUG(D_lookup)
514 debug_printf_indent("re-using cached connection to LDAP server %s%s\n",
515 host, porttext);
516
517 /* Bind with the user/password supplied, or an anonymous bind if these values
518 are NULL, unless a cached connection is already bound with the same values. */
519
520 if ( !lcp->bound
521 || !lcp->user && user
522 || lcp->user && !user
523 || lcp->user && user && Ustrcmp(lcp->user, user) != 0
524 || !lcp->password && password
525 || lcp->password && !password
526 || lcp->password && password && Ustrcmp(lcp->password, password) != 0
527 )
528 {
529 DEBUG(D_lookup) debug_printf_indent("%sbinding with user=%s password=%s\n",
530 lcp->bound ? "re-" : "", user, password);
531
532 if (eldap_start_tls && !lcp->is_start_tls_called && !ldapi)
533 {
534 #if defined(LDAP_OPT_X_TLS) && !defined(LDAP_LIB_SOLARIS)
535 /* The Oracle LDAP libraries (LDAP_LIB_TYPE=SOLARIS) don't support this.
536 * Note: moreover, they appear to now define LDAP_OPT_X_TLS and still not
537 * export an ldap_start_tls_s symbol.
538 */
539 if ( (rc = ldap_start_tls_s(lcp->ld, NULL, NULL)) != LDAP_SUCCESS)
540 {
541 *errmsg = string_sprintf("failed to initiate TLS processing on an "
542 "LDAP session to server %s%s - ldap_start_tls_s() returned %d:"
543 " %s", host, porttext, rc, ldap_err2string(rc));
544 goto RETURN_ERROR;
545 }
546 lcp->is_start_tls_called = TRUE;
547 #else
548 DEBUG(D_lookup) debug_printf_indent("TLS initiation not supported with this Exim"
549 " and your LDAP library.\n");
550 #endif
551 }
552 if ((msgid = ldap_bind(lcp->ld, CS user, CS password, LDAP_AUTH_SIMPLE))
553 == -1)
554 {
555 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
556 "%s%s - ldap_bind() returned -1", host, porttext);
557 goto RETURN_ERROR;
558 }
559
560 if ((rc = ldap_result(lcp->ld, msgid, 1, timeoutptr, &result)) <= 0)
561 {
562 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
563 "%s%s - LDAP error: %s", host, porttext,
564 rc == -1 ? "result retrieval failed" : "timeout" );
565 result = NULL;
566 goto RETURN_ERROR;
567 }
568
569 rc = ldap_result2error(lcp->ld, result, 0);
570
571 /* Invalid credentials when just checking credentials returns FAIL. This
572 stops any further servers being tried. */
573
574 if (search_type == SEARCH_LDAP_AUTH && rc == LDAP_INVALID_CREDENTIALS)
575 {
576 DEBUG(D_lookup)
577 debug_printf_indent("Invalid credentials: ldapauth returns FAIL\n");
578 error_yield = FAIL;
579 goto RETURN_ERROR_NOMSG;
580 }
581
582 /* Otherwise we have a problem that doesn't stop further servers from being
583 tried. */
584
585 if (rc != LDAP_SUCCESS)
586 {
587 *errmsg = string_sprintf("failed to bind the LDAP connection to server "
588 "%s%s - LDAP error %d: %s", host, porttext, rc, ldap_err2string(rc));
589 goto RETURN_ERROR;
590 }
591
592 /* Successful bind */
593
594 lcp->bound = TRUE;
595 lcp->user = !user ? NULL : string_copy(user);
596 lcp->password = !password ? NULL : string_copy(password);
597
598 ldap_msgfree(result);
599 result = NULL;
600 }
601
602 /* If we are just checking credentials, return OK. */
603
604 if (search_type == SEARCH_LDAP_AUTH)
605 {
606 DEBUG(D_lookup) debug_printf_indent("Bind succeeded: ldapauth returns OK\n");
607 goto RETURN_OK;
608 }
609
610 /* Before doing the search, set the time and size limits (if given). Here again
611 the different implementations of LDAP have chosen to do things differently. */
612
613 #if defined(LDAP_OPT_SIZELIMIT)
614 ldap_set_option(lcp->ld, LDAP_OPT_SIZELIMIT, (void *)&sizelimit);
615 ldap_set_option(lcp->ld, LDAP_OPT_TIMELIMIT, (void *)&timelimit);
616 #else
617 lcp->ld->ld_sizelimit = sizelimit;
618 lcp->ld->ld_timelimit = timelimit;
619 #endif
620
621 /* Similarly for dereferencing aliases. Don't know if this is possible on
622 an LDAP library without LDAP_OPT_DEREF. */
623
624 #if defined(LDAP_OPT_DEREF)
625 ldap_set_option(lcp->ld, LDAP_OPT_DEREF, (void *)&dereference);
626 #endif
627
628 /* Similarly for the referral setting; should the library follow referrals that
629 the LDAP server returns? The conditional is just in case someone uses a library
630 without it. */
631
632 #if defined(LDAP_OPT_REFERRALS)
633 ldap_set_option(lcp->ld, LDAP_OPT_REFERRALS, referrals);
634 #endif
635
636 /* Start the search on the server. */
637
638 DEBUG(D_lookup) debug_printf_indent("Start search\n");
639
640 msgid = ldap_search(lcp->ld, ludp->lud_dn, ludp->lud_scope, ludp->lud_filter,
641 ludp->lud_attrs, 0);
642
643 if (msgid == -1)
644 {
645 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
646 int err;
647 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
648 *errmsg = string_sprintf("ldap_search failed: %d, %s", err,
649 ldap_err2string(err));
650 #else
651 *errmsg = string_sprintf("ldap_search failed");
652 #endif
653
654 goto RETURN_ERROR;
655 }
656
657 /* Loop to pick up results as they come in, setting a timeout if one was
658 given. */
659
660 while ((rc = ldap_result(lcp->ld, msgid, 0, timeoutptr, &result)) ==
661 LDAP_RES_SEARCH_ENTRY)
662 {
663 LDAPMessage *e;
664 int valuecount; /* We can see an attr spread across several
665 entries. If B is derived from A and we request
666 A and the directory contains both, A and B,
667 then we get two entries, one for A and one for B.
668 Here we just count the values per entry */
669
670 DEBUG(D_lookup) debug_printf_indent("LDAP result loop\n");
671
672 for(e = ldap_first_entry(lcp->ld, result), valuecount = 0;
673 e;
674 e = ldap_next_entry(lcp->ld, e))
675 {
676 uschar *new_dn;
677 BOOL insert_space = FALSE;
678
679 DEBUG(D_lookup) debug_printf_indent("LDAP entry loop\n");
680
681 rescount++; /* Count results */
682
683 /* Results for multiple entries values are separated by newlines. */
684
685 if (data) data = string_catn(data, US"\n", 1);
686
687 /* Get the DN from the last result. */
688
689 if ((new_dn = US ldap_get_dn(lcp->ld, e)))
690 {
691 if (dn)
692 {
693 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
694 ldap_memfree(dn);
695 #else /* OPENLDAP 1, UMich, Solaris */
696 free(dn);
697 #endif
698 }
699 /* Save for later */
700 dn = new_dn;
701 }
702
703 /* If the data we want is actually the DN rather than any attribute values,
704 (an "ldapdn" search) add it to the data string. If there are multiple
705 entries, the DNs will be concatenated, but we test for this case below, as
706 for SEARCH_LDAP_SINGLE, and give an error. */
707
708 if (search_type == SEARCH_LDAP_DN) /* Do not amalgamate these into one */
709 { /* condition, because of the else */
710 if (new_dn) /* below, that's for the first only */
711 {
712 data = string_cat(data, new_dn);
713 (void) string_from_gstring(data);
714 attribute_found = TRUE;
715 }
716 }
717
718 /* Otherwise, loop through the entry, grabbing attribute values. If there's
719 only one attribute being retrieved, no attribute name is given, and the
720 result is not quoted. Multiple values are separated by (comma).
721 If more than one attribute is being retrieved, the data is given as a
722 sequence of name=value pairs, separated by (space), with the value always in quotes.
723 If there are multiple values, they are given within the quotes, comma separated. */
724
725 else for (uschar * attr = US ldap_first_attribute(lcp->ld, e, &ber);
726 attr; attr = US ldap_next_attribute(lcp->ld, e, ber))
727 {
728 DEBUG(D_lookup) debug_printf_indent("LDAP attr loop\n");
729
730 /* In case of attrs_requested == 1 we just count the values, in all other cases
731 (0, >1) we count the values per attribute */
732 if (attrs_requested != 1) valuecount = 0;
733
734 if (attr[0] != 0)
735 {
736 /* Get array of values for this attribute. */
737
738 if ((firstval = values = USS ldap_get_values(lcp->ld, e, CS attr)))
739 {
740 if (attrs_requested != 1)
741 {
742 if (insert_space)
743 data = string_catn(data, US" ", 1);
744 else
745 insert_space = TRUE;
746 data = string_cat(data, attr);
747 data = string_catn(data, US"=\"", 2);
748 }
749
750 while (*values)
751 {
752 uschar *value = *values;
753 int len = Ustrlen(value);
754 ++valuecount;
755
756 DEBUG(D_lookup) debug_printf_indent("LDAP value loop %s:%s\n", attr, value);
757
758 /* In case we requested one attribute only but got several times
759 into that attr loop, we need to append the additional values.
760 (This may happen if you derive attributeTypes B and C from A and
761 then query for A.) In all other cases we detect the different
762 attribute and append only every non first value. */
763
764 if (data && valuecount > 1)
765 data = string_catn(data, US",", 1);
766
767 /* For multiple attributes, the data is in quotes. We must escape
768 internal quotes, backslashes, newlines, and must double commas. */
769
770 if (attrs_requested != 1)
771 for (int j = 0; j < len; j++)
772 {
773 if (value[j] == '\n')
774 data = string_catn(data, US"\\n", 2);
775 else if (value[j] == ',')
776 data = string_catn(data, US",,", 2);
777 else
778 {
779 if (value[j] == '\"' || value[j] == '\\')
780 data = string_catn(data, US"\\", 1);
781 data = string_catn(data, value+j, 1);
782 }
783 }
784
785 /* For single attributes, just double commas */
786
787 else
788 for (int j = 0; j < len; j++)
789 if (value[j] == ',')
790 data = string_catn(data, US",,", 2);
791 else
792 data = string_catn(data, value+j, 1);
793
794
795 /* Move on to the next value */
796
797 values++;
798 attribute_found = TRUE;
799 }
800
801 /* Closing quote at the end of the data for a named attribute. */
802
803 if (attrs_requested != 1)
804 data = string_catn(data, US"\"", 1);
805
806 /* Free the values */
807
808 ldap_value_free(CSS firstval);
809 }
810 }
811
812 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
813
814 /* Netscape and OpenLDAP2 LDAP's attrs are dynamically allocated and need
815 to be freed. UMich LDAP stores them in static storage and does not require
816 this. */
817
818 ldap_memfree(attr);
819 #endif
820 } /* End "for" loop for extracting attributes from an entry */
821 } /* End "for" loop for extracting entries from a result */
822
823 /* Free the result */
824
825 ldap_msgfree(result);
826 result = NULL;
827 } /* End "while" loop for multiple results */
828
829 /* Terminate the dynamic string that we have built and reclaim unused store.
830 In the odd case of a single attribute with zero-length value, allocate
831 an empty string. */
832
833 if (!data) data = string_get(1);
834 (void) string_from_gstring(data);
835 gstring_release_unused(data);
836
837 /* Copy the last dn into eldap_dn */
838
839 if (dn)
840 {
841 eldap_dn = string_copy(dn);
842 #if defined LDAP_LIB_NETSCAPE || defined LDAP_LIB_OPENLDAP2
843 ldap_memfree(dn);
844 #else /* OPENLDAP 1, UMich, Solaris */
845 free(dn);
846 #endif
847 }
848
849 DEBUG(D_lookup) debug_printf_indent("search ended by ldap_result yielding %d\n",rc);
850
851 if (rc == 0)
852 {
853 *errmsg = US"ldap_result timed out";
854 goto RETURN_ERROR;
855 }
856
857 /* A return code of -1 seems to mean "ldap_result failed internally or couldn't
858 provide you with a message". Other error states seem to exist where
859 ldap_result() didn't give us any message from the server at all, leaving result
860 set to NULL. Apparently, "the error parameters of the LDAP session handle will
861 be set accordingly". That's the best we can do to retrieve an error status; we
862 can't use functions like ldap_result2error because they parse a message from
863 the server, which we didn't get.
864
865 Annoyingly, the different implementations of LDAP have gone for different
866 methods of handling error codes and generating error messages. */
867
868 if (rc == -1 || !result)
869 {
870 int err;
871 DEBUG(D_lookup) debug_printf_indent("ldap_result failed\n");
872
873 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
874 ldap_get_option(lcp->ld, LDAP_OPT_ERROR_NUMBER, &err);
875 *errmsg = string_sprintf("ldap_result failed: %d, %s",
876 err, ldap_err2string(err));
877
878 #elif defined LDAP_LIB_NETSCAPE
879 /* Dubious (surely 'matched' is spurious here?) */
880 (void)ldap_get_lderrno(lcp->ld, &matched, &error1);
881 *errmsg = string_sprintf("ldap_result failed: %s (%s)", error1, matched);
882
883 #else /* UMich LDAP aka OpenLDAP 1.x */
884 *errmsg = string_sprintf("ldap_result failed: %d, %s",
885 lcp->ld->ld_errno, ldap_err2string(lcp->ld->ld_errno));
886 #endif
887
888 goto RETURN_ERROR;
889 }
890
891 /* A return code that isn't -1 doesn't necessarily mean there were no problems
892 with the search. The message must be an LDAP_RES_SEARCH_RESULT or
893 LDAP_RES_SEARCH_REFERENCE or else it's something we can't handle. Some versions
894 of LDAP do not define LDAP_RES_SEARCH_REFERENCE (LDAP v1 is one, it seems). So
895 we don't provide that functionality when we can't. :-) */
896
897 if (rc != LDAP_RES_SEARCH_RESULT
898 #ifdef LDAP_RES_SEARCH_REFERENCE
899 && rc != LDAP_RES_SEARCH_REFERENCE
900 #endif
901 )
902 {
903 *errmsg = string_sprintf("ldap_result returned unexpected code %d", rc);
904 goto RETURN_ERROR;
905 }
906
907 /* We have a result message from the server. This doesn't yet mean all is well.
908 We need to parse the message to find out exactly what's happened. */
909
910 #if defined LDAP_LIB_SOLARIS || defined LDAP_LIB_OPENLDAP2
911 ldap_rc = rc;
912 ldap_parse_rc = ldap_parse_result(lcp->ld, result, &rc, CSS &matched,
913 CSS &error2, NULL, NULL, 0);
914 DEBUG(D_lookup) debug_printf_indent("ldap_parse_result: %d\n", ldap_parse_rc);
915 if (ldap_parse_rc < 0 &&
916 (ldap_parse_rc != LDAP_NO_RESULTS_RETURNED
917 #ifdef LDAP_RES_SEARCH_REFERENCE
918 || ldap_rc != LDAP_RES_SEARCH_REFERENCE
919 #endif
920 ))
921 {
922 *errmsg = string_sprintf("ldap_parse_result failed %d", ldap_parse_rc);
923 goto RETURN_ERROR;
924 }
925 error1 = US ldap_err2string(rc);
926
927 #elif defined LDAP_LIB_NETSCAPE
928 /* Dubious (it doesn't reference 'result' at all!) */
929 rc = ldap_get_lderrno(lcp->ld, &matched, &error1);
930
931 #else /* UMich LDAP aka OpenLDAP 1.x */
932 rc = ldap_result2error(lcp->ld, result, 0);
933 error1 = ldap_err2string(rc);
934 error2 = lcp->ld->ld_error;
935 matched = lcp->ld->ld_matched;
936 #endif
937
938 /* Process the status as follows:
939
940 (1) If we get LDAP_SIZELIMIT_EXCEEDED, just carry on, to return the
941 truncated result list.
942
943 (2) If we get LDAP_RES_SEARCH_REFERENCE, also just carry on. This was a
944 submitted patch that is reported to "do the right thing" with Solaris
945 LDAP libraries. (The problem it addresses apparently does not occur with
946 Open LDAP.)
947
948 (3) The range of errors defined by LDAP_NAME_ERROR generally mean "that
949 object does not, or cannot, exist in the database". For those cases we
950 fail the lookup.
951
952 (4) All other non-successes here are treated as some kind of problem with
953 the lookup, so return DEFER (which is the default in error_yield).
954 */
955
956 DEBUG(D_lookup) debug_printf_indent("ldap_parse_result yielded %d: %s\n",
957 rc, ldap_err2string(rc));
958
959 if (rc != LDAP_SUCCESS && rc != LDAP_SIZELIMIT_EXCEEDED
960 #ifdef LDAP_RES_SEARCH_REFERENCE
961 && rc != LDAP_RES_SEARCH_REFERENCE
962 #endif
963 )
964 {
965 *errmsg = string_sprintf("LDAP search failed - error %d: %s%s%s%s%s",
966 rc,
967 error1 ? error1 : US"",
968 error2 && error2[0] ? US"/" : US"",
969 error2 ? error2 : US"",
970 matched && matched[0] ? US"/" : US"",
971 matched ? matched : US"");
972
973 #if defined LDAP_NAME_ERROR
974 if (LDAP_NAME_ERROR(rc))
975 #elif defined NAME_ERROR /* OPENLDAP1 calls it this */
976 if (NAME_ERROR(rc))
977 #else
978 if (rc == LDAP_NO_SUCH_OBJECT)
979 #endif
980
981 {
982 DEBUG(D_lookup) debug_printf_indent("lookup failure forced\n");
983 error_yield = FAIL;
984 }
985 goto RETURN_ERROR;
986 }
987
988 /* The search succeeded. Check if we have too many results */
989
990 if (search_type != SEARCH_LDAP_MULTIPLE && rescount > 1)
991 {
992 *errmsg = string_sprintf("LDAP search: more than one entry (%d) was returned "
993 "(filter not specific enough?)", rescount);
994 goto RETURN_ERROR_BREAK;
995 }
996
997 /* Check if we have too few (zero) entries */
998
999 if (rescount < 1)
1000 {
1001 *errmsg = US"LDAP search: no results";
1002 error_yield = FAIL;
1003 goto RETURN_ERROR_BREAK;
1004 }
1005
1006 /* If an entry was found, but it had no attributes, we behave as if no entries
1007 were found, that is, the lookup failed. */
1008
1009 if (!attribute_found)
1010 {
1011 *errmsg = US"LDAP search: found no attributes";
1012 error_yield = FAIL;
1013 goto RETURN_ERROR;
1014 }
1015
1016 /* Otherwise, it's all worked */
1017
1018 DEBUG(D_lookup) debug_printf_indent("LDAP search: returning: %s\n", data->s);
1019 *res = data->s;
1020
1021 RETURN_OK:
1022 if (result) ldap_msgfree(result);
1023 ldap_free_urldesc(ludp);
1024 return OK;
1025
1026 /* Error returns */
1027
1028 RETURN_ERROR_BREAK:
1029 *defer_break = TRUE;
1030
1031 RETURN_ERROR:
1032 DEBUG(D_lookup) debug_printf_indent("%s\n", *errmsg);
1033
1034 RETURN_ERROR_NOMSG:
1035 if (result) ldap_msgfree(result);
1036 if (ludp) ldap_free_urldesc(ludp);
1037
1038 #if defined LDAP_LIB_OPENLDAP2
1039 if (error2) ldap_memfree(error2);
1040 if (matched) ldap_memfree(matched);
1041 #endif
1042
1043 return error_yield;
1044 }
1045
1046
1047
1048 /*************************************************
1049 * Internal search control function *
1050 *************************************************/
1051
1052 /* This function is called from eldap_find(), eldapauth_find(), eldapdn_find(),
1053 and eldapm_find() with a difference in the "search_type" argument. It controls
1054 calls to perform_ldap_search() which actually does the work. We call that
1055 repeatedly for certain types of defer in the case when the URL contains no host
1056 name and eldap_default_servers is set to a list of servers to try. This gives
1057 more control than just passing over a list of hosts to ldap_open() because it
1058 handles other kinds of defer as well as just a failure to open. Note that the
1059 URL is defined to contain either zero or one "hostport" only.
1060
1061 Parameter data in addition to the URL can be passed as preceding text in the
1062 string, as items of the form XXX=yyy. The URL itself can be detected because it
1063 must begin "ldapx://", where x is empty, s, or i.
1064
1065 Arguments:
1066 ldap_url the URL to be looked up, optionally preceded by other parameter
1067 settings
1068 search_type SEARCH_LDAP_MULTIPLE allows values from multiple entries
1069 SEARCH_LDAP_SINGLE allows values from one entry only
1070 SEARCH_LDAP_DN gets the DN from one entry
1071 res set to point at the result
1072 errmsg set to point a message if result is not OK
1073
1074 Returns: OK or FAIL or DEFER
1075 */
1076
1077 static int
1078 control_ldap_search(const uschar *ldap_url, int search_type, uschar **res,
1079 uschar **errmsg)
1080 {
1081 BOOL defer_break = FALSE;
1082 int timelimit = LDAP_NO_LIMIT;
1083 int sizelimit = LDAP_NO_LIMIT;
1084 int tcplimit = 0;
1085 int sep = 0;
1086 int dereference = LDAP_DEREF_NEVER;
1087 void* referrals = LDAP_OPT_ON;
1088 const uschar *url = ldap_url;
1089 const uschar *p;
1090 uschar *user = NULL;
1091 uschar *password = NULL;
1092 uschar *local_servers = NULL;
1093 uschar *server;
1094 const uschar *list;
1095 uschar buffer[512];
1096
1097 while (isspace(*url)) url++;
1098
1099 /* Until the string begins "ldap", search for the other parameter settings that
1100 are recognized. They are of the form NAME=VALUE, with the value being
1101 optionally double-quoted. There must still be a space after it, however. No
1102 NAME has the value "ldap". */
1103
1104 while (strncmpic(url, US"ldap", 4) != 0)
1105 {
1106 const uschar *name = url;
1107 while (*url && *url != '=') url++;
1108 if (*url == '=')
1109 {
1110 int namelen;
1111 uschar *value;
1112 namelen = ++url - name;
1113 value = string_dequote(&url);
1114 if (isspace(*url))
1115 {
1116 if (strncmpic(name, US"USER=", namelen) == 0) user = value;
1117 else if (strncmpic(name, US"PASS=", namelen) == 0) password = value;
1118 else if (strncmpic(name, US"SIZE=", namelen) == 0) sizelimit = Uatoi(value);
1119 else if (strncmpic(name, US"TIME=", namelen) == 0) timelimit = Uatoi(value);
1120 else if (strncmpic(name, US"CONNECT=", namelen) == 0) tcplimit = Uatoi(value);
1121 else if (strncmpic(name, US"NETTIME=", namelen) == 0) tcplimit = Uatoi(value);
1122 else if (strncmpic(name, US"SERVERS=", namelen) == 0) local_servers = value;
1123
1124 /* Don't know if all LDAP libraries have LDAP_OPT_DEREF */
1125
1126 #ifdef LDAP_OPT_DEREF
1127 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1128 {
1129 if (strcmpic(value, US"never") == 0) dereference = LDAP_DEREF_NEVER;
1130 else if (strcmpic(value, US"searching") == 0)
1131 dereference = LDAP_DEREF_SEARCHING;
1132 else if (strcmpic(value, US"finding") == 0)
1133 dereference = LDAP_DEREF_FINDING;
1134 if (strcmpic(value, US"always") == 0) dereference = LDAP_DEREF_ALWAYS;
1135 }
1136 #else
1137 else if (strncmpic(name, US"DEREFERENCE=", namelen) == 0)
1138 {
1139 *errmsg = string_sprintf("LDAP_OP_DEREF not defined in this LDAP "
1140 "library - cannot use \"dereference\"");
1141 DEBUG(D_lookup) debug_printf_indent("%s\n", *errmsg);
1142 return DEFER;
1143 }
1144 #endif
1145
1146 #ifdef LDAP_OPT_REFERRALS
1147 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1148 {
1149 if (strcmpic(value, US"follow") == 0) referrals = LDAP_OPT_ON;
1150 else if (strcmpic(value, US"nofollow") == 0) referrals = LDAP_OPT_OFF;
1151 else
1152 {
1153 *errmsg = US"LDAP option REFERRALS is not \"follow\" or \"nofollow\"";
1154 DEBUG(D_lookup) debug_printf_indent("%s\n", *errmsg);
1155 return DEFER;
1156 }
1157 }
1158 #else
1159 else if (strncmpic(name, US"REFERRALS=", namelen) == 0)
1160 {
1161 *errmsg = string_sprintf("LDAP_OP_REFERRALS not defined in this LDAP "
1162 "library - cannot use \"referrals\"");
1163 DEBUG(D_lookup) debug_printf_indent("%s\n", *errmsg);
1164 return DEFER;
1165 }
1166 #endif
1167
1168 else
1169 {
1170 *errmsg =
1171 string_sprintf("unknown parameter \"%.*s\" precedes LDAP URL",
1172 namelen, name);
1173 DEBUG(D_lookup) debug_printf_indent("LDAP query error: %s\n", *errmsg);
1174 return DEFER;
1175 }
1176 while (isspace(*url)) url++;
1177 continue;
1178 }
1179 }
1180 *errmsg = US"malformed parameter setting precedes LDAP URL";
1181 DEBUG(D_lookup) debug_printf_indent("LDAP query error: %s\n", *errmsg);
1182 return DEFER;
1183 }
1184
1185 /* If user is set, de-URL-quote it. Some LDAP libraries do this for themselves,
1186 but it seems that not all behave like this. The DN for the user is often the
1187 result of ${quote_ldap_dn:...} quoting, which does apply URL quoting, because
1188 that is needed when the DN is used as a base DN in a query. Sigh. This is all
1189 far too complicated. */
1190
1191 if (user)
1192 {
1193 uschar *t = user;
1194 for (uschar * s = user; *s != 0; s++)
1195 {
1196 int c, d;
1197 if (*s == '%' && isxdigit(c=s[1]) && isxdigit(d=s[2]))
1198 {
1199 c = tolower(c);
1200 d = tolower(d);
1201 *t++ =
1202 (((c >= 'a')? (10 + c - 'a') : c - '0') << 4) |
1203 ((d >= 'a')? (10 + d - 'a') : d - '0');
1204 s += 2;
1205 }
1206 else *t++ = *s;
1207 }
1208 *t = 0;
1209 }
1210
1211 DEBUG(D_lookup)
1212 debug_printf_indent("LDAP parameters: user=%s pass=%s size=%d time=%d connect=%d "
1213 "dereference=%d referrals=%s\n", user, password, sizelimit, timelimit,
1214 tcplimit, dereference, referrals == LDAP_OPT_ON ? "on" : "off");
1215
1216 /* If the request is just to check authentication, some credentials must
1217 be given. The password must not be empty because LDAP binds with an empty
1218 password are considered anonymous, and will succeed on most installations. */
1219
1220 if (search_type == SEARCH_LDAP_AUTH)
1221 {
1222 if (!user || !password)
1223 {
1224 *errmsg = US"ldapauth lookups must specify the username and password";
1225 return DEFER;
1226 }
1227 if (!*password)
1228 {
1229 DEBUG(D_lookup) debug_printf_indent("Empty password: ldapauth returns FAIL\n");
1230 return FAIL;
1231 }
1232 }
1233
1234 /* Check for valid ldap url starters */
1235
1236 p = url + 4;
1237 if (tolower(*p) == 's' || tolower(*p) == 'i') p++;
1238 if (Ustrncmp(p, "://", 3) != 0)
1239 {
1240 *errmsg = string_sprintf("LDAP URL does not start with \"ldap://\", "
1241 "\"ldaps://\", or \"ldapi://\" (it starts with \"%.16s...\")", url);
1242 DEBUG(D_lookup) debug_printf_indent("LDAP query error: %s\n", *errmsg);
1243 return DEFER;
1244 }
1245
1246 /* No default servers, or URL contains a server name: just one attempt */
1247
1248 if (!eldap_default_servers && !local_servers || p[3] != '/')
1249 return perform_ldap_search(url, NULL, 0, search_type, res, errmsg,
1250 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1251 referrals);
1252
1253 /* Loop through the default servers until OK or FAIL. Use local_servers list
1254 * if defined in the lookup, otherwise use the global default list */
1255 list = !local_servers ? eldap_default_servers : local_servers;
1256 while ((server = string_nextinlist(&list, &sep, buffer, sizeof(buffer))))
1257 {
1258 int rc;
1259 int port = 0;
1260 uschar *colon = Ustrchr(server, ':');
1261 if (colon)
1262 {
1263 *colon = 0;
1264 port = Uatoi(colon+1);
1265 }
1266 rc = perform_ldap_search(url, server, port, search_type, res, errmsg,
1267 &defer_break, user, password, sizelimit, timelimit, tcplimit, dereference,
1268 referrals);
1269 if (rc != DEFER || defer_break) return rc;
1270 }
1271
1272 return DEFER;
1273 }
1274
1275
1276
1277 /*************************************************
1278 * Find entry point *
1279 *************************************************/
1280
1281 /* See local README for interface description. The different kinds of search
1282 are handled by a common function, with a flag to differentiate between them.
1283 The handle and filename arguments are not used. */
1284
1285 static int
1286 eldap_find(void * handle, const uschar * filename, const uschar * ldap_url,
1287 int length, uschar ** result, uschar ** errmsg, uint * do_cache,
1288 const uschar * opts)
1289 {
1290 /* Keep picky compilers happy */
1291 do_cache = do_cache;
1292 return(control_ldap_search(ldap_url, SEARCH_LDAP_SINGLE, result, errmsg));
1293 }
1294
1295 static int
1296 eldapm_find(void * handle, const uschar * filename, const uschar * ldap_url,
1297 int length, uschar ** result, uschar ** errmsg, uint * do_cache,
1298 const uschar * opts)
1299 {
1300 /* Keep picky compilers happy */
1301 do_cache = do_cache;
1302 return(control_ldap_search(ldap_url, SEARCH_LDAP_MULTIPLE, result, errmsg));
1303 }
1304
1305 static int
1306 eldapdn_find(void * handle, const uschar * filename, const uschar * ldap_url,
1307 int length, uschar ** result, uschar ** errmsg, uint * do_cache,
1308 const uschar * opts)
1309 {
1310 /* Keep picky compilers happy */
1311 do_cache = do_cache;
1312 return(control_ldap_search(ldap_url, SEARCH_LDAP_DN, result, errmsg));
1313 }
1314
1315 int
1316 eldapauth_find(void * handle, const uschar * filename, const uschar * ldap_url,
1317 int length, uschar ** result, uschar ** errmsg, uint * do_cache)
1318 {
1319 /* Keep picky compilers happy */
1320 do_cache = do_cache;
1321 return(control_ldap_search(ldap_url, SEARCH_LDAP_AUTH, result, errmsg));
1322 }
1323
1324
1325
1326 /*************************************************
1327 * Open entry point *
1328 *************************************************/
1329
1330 /* See local README for interface description. */
1331
1332 static void *
1333 eldap_open(const uschar * filename, uschar ** errmsg)
1334 {
1335 return (void *)(1); /* Just return something non-null */
1336 }
1337
1338
1339
1340 /*************************************************
1341 * Tidy entry point *
1342 *************************************************/
1343
1344 /* See local README for interface description.
1345 Make sure that eldap_dn does not refer to reclaimed or worse, freed store */
1346
1347 static void
1348 eldap_tidy(void)
1349 {
1350 LDAP_CONNECTION *lcp = NULL;
1351 eldap_dn = NULL;
1352
1353 while ((lcp = ldap_connections) != NULL)
1354 {
1355 DEBUG(D_lookup) debug_printf_indent("unbind LDAP connection to %s:%d\n", lcp->host,
1356 lcp->port);
1357 if(lcp->bound == TRUE)
1358 ldap_unbind(lcp->ld);
1359 ldap_connections = lcp->next;
1360 }
1361 }
1362
1363
1364
1365 /*************************************************
1366 * Quote entry point *
1367 *************************************************/
1368
1369 /* LDAP quoting is unbelievably messy. For a start, two different levels of
1370 quoting have to be done: LDAP quoting, and URL quoting. The current
1371 specification is the result of a suggestion by Brian Candler. It recognizes
1372 two separate cases:
1373
1374 (1) For text that appears in a search filter, the following escapes are
1375 required (see RFC 2254):
1376
1377 * -> \2A
1378 ( -> \28
1379 ) -> \29
1380 \ -> \5C
1381 NULL -> \00
1382
1383 Then the entire filter text must be URL-escaped. This kind of quoting is
1384 implemented by ${quote_ldap:....}. Note that we can never have a NULL
1385 in the input string, because that's a terminator.
1386
1387 (2) For a DN that is part of a URL (i.e. the base DN), the characters
1388
1389 , + " \ < > ;
1390
1391 must be quoted by backslashing. See RFC 2253. Leading and trailing spaces
1392 must be escaped, as must a leading #. Then the string must be URL-quoted.
1393 This type of quoting is implemented by ${quote_ldap_dn:....}.
1394
1395 For URL quoting, the only characters that need not be quoted are the
1396 alphamerics and
1397
1398 ! $ ' ( ) * + - . _
1399
1400 All the others must be hexified and preceded by %. This includes the
1401 backslashes used for LDAP quoting.
1402
1403 For a DN that is given in the USER parameter for authentication, we need the
1404 same initial quoting as (2) but in this case, the result must NOT be
1405 URL-escaped, because it isn't a URL. The way this is handled is by
1406 de-URL-quoting the text when processing the USER parameter in
1407 control_ldap_search() above. That means that the same quote operator can be
1408 used. This has the additional advantage that spaces in the DN won't cause
1409 parsing problems. For example:
1410
1411 USER=cn=${quote_ldap_dn:$1},%20dc=example,%20dc=com
1412
1413 should be safe if there are spaces in $1.
1414
1415
1416 Arguments:
1417 s the string to be quoted
1418 opt additional option text or NULL if none
1419 only "dn" is recognized
1420
1421 Returns: the processed string or NULL for a bad option
1422 */
1423
1424
1425
1426 /* The characters in this string, together with alphanumerics, never need
1427 quoting in any way. */
1428
1429 #define ALWAYS_LITERAL "!$'-._"
1430
1431 /* The special characters in this string do not need to be URL-quoted. The set
1432 is a bit larger than the general literals. */
1433
1434 #define URL_NONQUOTE ALWAYS_LITERAL "()*+"
1435
1436 /* The following macros define the characters that are quoted by quote_ldap and
1437 quote_ldap_dn, respectively. */
1438
1439 #define LDAP_QUOTE "*()\\"
1440 #define LDAP_DN_QUOTE ",+\"\\<>;"
1441
1442
1443
1444 static uschar *
1445 eldap_quote(uschar *s, uschar *opt)
1446 {
1447 register int c;
1448 int count = 0;
1449 int len = 0;
1450 BOOL dn = FALSE;
1451 uschar *t = s;
1452 uschar *quoted;
1453
1454 /* Test for a DN quotation. */
1455
1456 if (opt != NULL)
1457 {
1458 if (Ustrcmp(opt, "dn") != 0) return NULL; /* No others recognized */
1459 dn = TRUE;
1460 }
1461
1462 /* Compute how much extra store we need for the string. This doesn't have to be
1463 exact as long as it isn't an underestimate. The worst case is the addition of 5
1464 extra bytes for a single character. This occurs for certain characters in DNs,
1465 where, for example, < turns into %5C%3C. For simplicity, we just add 5 for each
1466 possibly escaped character. The really fast way would be just to test for
1467 non-alphanumerics, but it is probably better to spot a few others that are
1468 never escaped, because if there are no specials at all, we can avoid copying
1469 the string. */
1470
1471 while ((c = *t++) != 0)
1472 {
1473 len++;
1474 if (!isalnum(c) && Ustrchr(ALWAYS_LITERAL, c) == NULL) count += 5;
1475 }
1476 if (count == 0) return s;
1477
1478 /* Get sufficient store to hold the quoted string */
1479
1480 t = quoted = store_get(len + count + 1, is_tainted(s));
1481
1482 /* Handle plain quote_ldap */
1483
1484 if (!dn)
1485 {
1486 while ((c = *s++) != 0)
1487 {
1488 if (!isalnum(c))
1489 {
1490 if (Ustrchr(LDAP_QUOTE, c) != NULL)
1491 {
1492 sprintf(CS t, "%%5C%02X", c); /* e.g. * => %5C2A */
1493 t += 5;
1494 continue;
1495 }
1496 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1497 {
1498 sprintf(CS t, "%%%02X", c);
1499 t += 3;
1500 continue;
1501 }
1502 }
1503 *t++ = c; /* unquoted character */
1504 }
1505 }
1506
1507 /* Handle quote_ldap_dn */
1508
1509 else
1510 {
1511 uschar *ss = s + len;
1512
1513 /* Find the last char before any trailing spaces */
1514
1515 while (ss > s && ss[-1] == ' ') ss--;
1516
1517 /* Quote leading spaces and sharps */
1518
1519 for (; s < ss; s++)
1520 {
1521 if (*s != ' ' && *s != '#') break;
1522 sprintf(CS t, "%%5C%%%02X", *s);
1523 t += 6;
1524 }
1525
1526 /* Handle the rest of the string, up to the trailing spaces */
1527
1528 while (s < ss)
1529 {
1530 c = *s++;
1531 if (!isalnum(c))
1532 {
1533 if (Ustrchr(LDAP_DN_QUOTE, c) != NULL)
1534 {
1535 Ustrncpy(t, US"%5C", 3); /* insert \ where needed */
1536 t += 3; /* fall through to check URL */
1537 }
1538 if (Ustrchr(URL_NONQUOTE, c) == NULL) /* e.g. ] => %5D */
1539 {
1540 sprintf(CS t, "%%%02X", c);
1541 t += 3;
1542 continue;
1543 }
1544 }
1545 *t++ = c; /* unquoted character, or non-URL quoted after %5C */
1546 }
1547
1548 /* Handle the trailing spaces */
1549
1550 while (*ss++ != 0)
1551 {
1552 Ustrncpy(t, US"%5C%20", 6);
1553 t += 6;
1554 }
1555 }
1556
1557 /* Terminate the new string and return */
1558
1559 *t = 0;
1560 return quoted;
1561 }
1562
1563
1564
1565 /*************************************************
1566 * Version reporting entry point *
1567 *************************************************/
1568
1569 /* See local README for interface description. */
1570
1571 #include "../version.h"
1572
1573 void
1574 ldap_version_report(FILE *f)
1575 {
1576 #ifdef DYNLOOKUP
1577 fprintf(f, "Library version: LDAP: Exim version %s\n", EXIM_VERSION_STR);
1578 #endif
1579 }
1580
1581
1582 static lookup_info ldap_lookup_info = {
1583 .name = US"ldap", /* lookup name */
1584 .type = lookup_querystyle, /* query-style lookup */
1585 .open = eldap_open, /* open function */
1586 .check = NULL, /* check function */
1587 .find = eldap_find, /* find function */
1588 .close = NULL, /* no close function */
1589 .tidy = eldap_tidy, /* tidy function */
1590 .quote = eldap_quote, /* quoting function */
1591 .version_report = ldap_version_report /* version reporting */
1592 };
1593
1594 static lookup_info ldapdn_lookup_info = {
1595 .name = US"ldapdn", /* lookup name */
1596 .type = lookup_querystyle, /* query-style lookup */
1597 .open = eldap_open, /* sic */ /* open function */
1598 .check = NULL, /* check function */
1599 .find = eldapdn_find, /* find function */
1600 .close = NULL, /* no close function */
1601 .tidy = eldap_tidy, /* sic */ /* tidy function */
1602 .quote = eldap_quote, /* sic */ /* quoting function */
1603 .version_report = NULL /* no version reporting (redundant) */
1604 };
1605
1606 static lookup_info ldapm_lookup_info = {
1607 .name = US"ldapm", /* lookup name */
1608 .type = lookup_querystyle, /* query-style lookup */
1609 .open = eldap_open, /* sic */ /* open function */
1610 .check = NULL, /* check function */
1611 .find = eldapm_find, /* find function */
1612 .close = NULL, /* no close function */
1613 .tidy = eldap_tidy, /* sic */ /* tidy function */
1614 .quote = eldap_quote, /* sic */ /* quoting function */
1615 .version_report = NULL /* no version reporting (redundant) */
1616 };
1617
1618 #ifdef DYNLOOKUP
1619 #define ldap_lookup_module_info _lookup_module_info
1620 #endif
1621
1622 static lookup_info *_lookup_list[] = { &ldap_lookup_info, &ldapdn_lookup_info, &ldapm_lookup_info };
1623 lookup_module_info ldap_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
1624
1625 /* End of lookups/ldap.c */