]> git.sur5r.net Git - openldap/blob - servers/slapd/sasl.c
Make SASL authorization work for NULL, "u:", and "dn:" authz strings.
[openldap] / servers / slapd / sasl.c
1 /* $OpenLDAP$ */
2 /*
3  * Copyright 1998-2000 The OpenLDAP Foundation, All Rights Reserved.
4  * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
5  */
6
7 #include "portable.h"
8
9 #include <ac/stdlib.h>
10 #include <stdio.h>
11
12 #include "slap.h"
13 #include "proto-slap.h"
14
15 #include <lber.h>
16 #include <ldap_log.h>
17
18 #ifdef HAVE_CYRUS_SASL
19 #include <limits.h>
20 #include <sasl.h>
21
22 #include <ldap_pvt.h>
23
24 #ifdef SLAPD_SPASSWD
25 #include <lutil.h>
26 #endif
27
28 static sasl_security_properties_t sasl_secprops;
29
30
31 static int
32 slap_sasl_log(
33         void *context,
34         int priority,
35         const char *message) 
36 {
37         Connection *conn = context;
38         int level;
39         const char * label;
40
41         if ( message == NULL ) {
42                 return SASL_BADPARAM;
43         }
44
45         switch (priority) {
46         case SASL_LOG_ERR:
47                 level = LDAP_DEBUG_ANY;
48                 label = "Error";
49                 break;
50         case SASL_LOG_WARNING:
51                 level = LDAP_DEBUG_TRACE;
52                 label = "Warning";
53                 break;
54         case SASL_LOG_INFO:
55                 level = LDAP_DEBUG_TRACE;
56                 label = "Info";
57                 break;
58         default:
59                 return SASL_BADPARAM;
60         }
61
62         Debug( level, "SASL [conn=%d] %s: %s\n",
63                 conn ? conn->c_connid: -1,
64                 label, message );
65
66         return SASL_OK;
67 }
68
69
70 /* Take any sort of identity string and return a DN with the "dn:" prefix. The
71    string returned in *dnptr is in its own allocated memory, and must be free'd 
72    by the calling process.
73    -Mark Adamson, Carnegie Mellon
74 */
75
76 int slap_sasl_getdn( Connection *conn, char *id, char **dnptr, int flags )
77 {
78         char *c, *c1, *dn=NULL;
79         int rc, len, len1;
80         sasl_conn_t *ctx;
81
82
83         Debug( LDAP_DEBUG_ARGS, "slap_sasl_getdn: id=%s\n", 
84       id?(*id?id:"<empty>"):"NULL",0,0 );
85
86         /* Blatantly anonymous ID */
87         len = strlen( "anonymous" );
88         if( id && !strncasecmp( id, "anonymous", len) && 
89                 ( id[len] == '\0' || id[len] == '@' ) ) {
90                 *dnptr = NULL;
91                 return( LDAP_SUCCESS );
92         }
93         ctx = conn->c_sasl_context;
94         dn = ch_strdup( id );
95         len = strlen( id );
96
97         /* An authcID will need to be prefixed with u: */
98         if( flags & FLAG_GETDN_AUTHCID ) {
99                 dn = ch_realloc( dn, len+3 );
100                 memmove( dn+2, dn, len+1 );
101                 dn[0] = 'u';
102                 dn[1] = ':';
103                 len += 2;
104         }
105
106         /* An authzID must be properly prefixed */
107         if( flags & FLAG_GETDN_AUTHZID && strncasecmp( dn, "u:", 2 ) &&
108           strncasecmp( dn, "dn:", 3 ) ) {
109                 ch_free( dn );
110                 *dnptr = NULL;
111                 return( LDAP_INAPPROPRIATE_AUTH );
112         }
113
114         /* Username strings */
115         len1  = strlen( ",cn=authzid" );
116         if( !strncasecmp( dn, "u:", 2 ) ) {
117                 len += strlen( "dn:uid=" ) + len1;
118
119                 /* Figure out how much data we have for the dn */
120                 rc = sasl_getprop( ctx, SASL_REALM, (void **)&c );
121                 if( rc != SASL_OK ) {
122                         Debug(LDAP_DEBUG_TRACE,
123                                 "getdn: getprop(REALM) failed!\n", 0,0,0);
124                         ch_free( dn );
125                         *dnptr = NULL;
126                         return( LDAP_OPERATIONS_ERROR );
127                 }
128                 if( c ) {
129                         len += strlen( c ) + strlen(",cn=" );
130                 }
131                 if( conn->c_sasl_bind_mech ) {
132                         len += strlen( conn->c_sasl_bind_mech ) + strlen( ",cn=mech" );
133                 }
134
135                 /* Build the new dn */
136                 c1 = dn;
137                 dn = ch_malloc( len );
138                 len = sprintf( dn, "dn:uid=%s", c1+2 );
139                 ch_free( c1 );
140
141                 if( c ) {
142                         len += sprintf( dn+len, ",cn=%s", c );
143                 }
144                 if( conn->c_sasl_bind_mech ) {
145                         len += sprintf( dn+len, ",cn=%s", conn->c_sasl_bind_mech );
146                 }
147                 strcpy( dn+len, ",cn=authzid" );
148                 len += len1;
149                 Debug( LDAP_DEBUG_TRACE, "getdn: u:id converted to %s\n", dn,0,0 );
150         }
151
152         /* DN strings that are a cn=authzid identity to run through regexp */
153         if( !strncasecmp( dn, "dn:", 3) && ( ( flags & FLAG_GETDN_FINAL ) == 0 ) ) {
154                 c1 = slap_sasl2dn( dn + 3 );
155                 if( c1 ) {
156                         ch_free( dn );
157                         dn = c1;
158                         /* Reaffix the dn: prefix if it was removed */
159                         if( strncasecmp( dn, "dn:", 3) ) {
160                                 c1 = dn;
161                                 dn = ch_malloc( strlen( c1 ) + 4 );
162                                 sprintf( dn, "dn:%s", c1 );
163                                 ch_free( c1 );
164                         }
165                         Debug( LDAP_DEBUG_TRACE, "getdn: dn:id converted to %s\n", dn,0,0 );
166                 }
167         }
168
169         if( ( flags & FLAG_GETDN_FINAL ) == 0 )  {
170                 dn_normalize( dn );
171         }
172
173         *dnptr = dn;
174         return( LDAP_SUCCESS );
175 }
176
177
178
179 static int
180 slap_sasl_authorize(
181         void *context,
182         const char *authcid,
183         const char *authzid,
184         const char **user,
185         const char **errstr)
186 {
187         char *authcDN, *authzDN;
188         int rc;
189         Connection *conn = context;
190
191         *user = NULL;
192
193         Debug( LDAP_DEBUG_ARGS, "SASL Authorize [conn=%ld]: "
194                 "authcid=\"%s\" authzid=\"%s\"\n",
195                 (long) (conn ? conn->c_connid : -1),
196                 authcid ? authcid : "<empty>",
197                 authzid ? authzid : "<empty>" );
198
199         /* Convert the identities to DN's. If no authzid was given, client will
200            be bound as the DN matching their username */
201         rc = slap_sasl_getdn( conn, (char *)authcid, &authcDN, FLAG_GETDN_AUTHCID );
202         if( rc != LDAP_SUCCESS ) {
203                 *errstr = ldap_err2string( rc );
204                 return SASL_NOAUTHZ;
205         }
206         if( ( authzid == NULL ) || !strcmp( authcid,authzid ) ) {
207                 Debug( LDAP_DEBUG_TRACE, "SASL Authorize [conn=%ld]: "
208                  "Using authcDN=%s\n", (long) (conn ? conn->c_connid : -1), authcDN,0 );
209                 *user = authcDN;
210                 *errstr = NULL;
211                 return SASL_OK;
212         }
213         rc = slap_sasl_getdn( conn, (char *)authzid, &authzDN, FLAG_GETDN_AUTHZID );
214         if( rc != LDAP_SUCCESS ) {
215                 ch_free( authcDN );
216                 *errstr = ldap_err2string( rc );
217                 return SASL_NOAUTHZ;
218         }
219
220         rc = slap_sasl_authorized( authcDN, authzDN );
221         if( rc ) {
222                 Debug( LDAP_DEBUG_TRACE, "SASL Authorize [conn=%ld]: "
223                         " authorization disallowed (%d)\n",
224                         (long) (conn ? conn->c_connid : -1), rc, 0 );
225                 *errstr = "not authorized";
226                 ch_free( authcDN );
227                 ch_free( authzDN );
228                 return SASL_NOAUTHZ;
229         }
230
231         Debug( LDAP_DEBUG_TRACE, "SASL Authorize [conn=%ld]: "
232                 " authorization allowed\n",
233                 (long) (conn ? conn->c_connid : -1), 0, 0 );
234
235         ch_free( authcDN );
236         *user = authzDN;
237         *errstr = NULL;
238         return SASL_OK;
239 }
240
241
242 static int
243 slap_sasl_err2ldap( int saslerr )
244 {
245         int rc;
246
247         switch (saslerr) {
248                 case SASL_CONTINUE:
249                         rc = LDAP_SASL_BIND_IN_PROGRESS;
250                         break;
251                 case SASL_FAIL:
252                         rc = LDAP_OTHER;
253                         break;
254                 case SASL_NOMEM:
255                         rc = LDAP_OTHER;
256                         break;
257                 case SASL_NOMECH:
258                         rc = LDAP_AUTH_METHOD_NOT_SUPPORTED;
259                         break;
260                 case SASL_BADAUTH:
261                         rc = LDAP_INVALID_CREDENTIALS;
262                         break;
263                 case SASL_NOAUTHZ:
264                         rc = LDAP_INSUFFICIENT_ACCESS;
265                         break;
266                 case SASL_TOOWEAK:
267                 case SASL_ENCRYPT:
268                         rc = LDAP_INAPPROPRIATE_AUTH;
269                         break;
270                 default:
271                         rc = LDAP_OTHER;
272                         break;
273         }
274
275         return rc;
276 }
277 #endif
278
279
280 int slap_sasl_init( void )
281 {
282 #ifdef HAVE_CYRUS_SASL
283         int rc;
284         static sasl_callback_t server_callbacks[] = {
285                 { SASL_CB_LOG, &slap_sasl_log, NULL },
286                 { SASL_CB_LIST_END, NULL, NULL }
287         };
288
289         sasl_set_alloc(
290                 ch_malloc,
291                 ch_calloc,
292                 ch_realloc,
293                 ch_free ); 
294
295         sasl_set_mutex(
296                 ldap_pvt_sasl_mutex_new,
297                 ldap_pvt_sasl_mutex_lock,
298                 ldap_pvt_sasl_mutex_unlock,
299                 ldap_pvt_sasl_mutex_dispose );
300
301         /* should provide callbacks for logging */
302         /* server name should be configurable */
303         rc = sasl_server_init( server_callbacks, "slapd" );
304
305         if( rc != SASL_OK ) {
306                 Debug( LDAP_DEBUG_ANY, "sasl_server_init failed\n",
307                         0, 0, 0 );
308                 return -1;
309         }
310
311         Debug( LDAP_DEBUG_TRACE, "slap_sasl_init: initialized!\n",
312                 0, 0, 0 );
313
314         /* default security properties */
315         memset( &sasl_secprops, '\0', sizeof(sasl_secprops) );
316     sasl_secprops.max_ssf = INT_MAX;
317     sasl_secprops.maxbufsize = 65536;
318     sasl_secprops.security_flags = SASL_SEC_NOPLAINTEXT|SASL_SEC_NOANONYMOUS;
319 #endif
320
321         return 0;
322 }
323
324 int slap_sasl_destroy( void )
325 {
326 #ifdef HAVE_CYRUS_SASL
327         sasl_done();
328 #endif
329         return 0;
330 }
331
332 int slap_sasl_open( Connection *conn )
333 {
334         int sc = LDAP_SUCCESS;
335
336 #ifdef HAVE_CYRUS_SASL
337         sasl_conn_t *ctx = NULL;
338         sasl_callback_t *session_callbacks;
339
340         assert( conn->c_sasl_context == NULL );
341         assert( conn->c_sasl_extra == NULL );
342
343         conn->c_sasl_layers = 0;
344
345         session_callbacks =
346                 ch_calloc( 3, sizeof(sasl_callback_t));
347         conn->c_sasl_extra = session_callbacks;
348
349         session_callbacks[0].id = SASL_CB_LOG;
350         session_callbacks[0].proc = &slap_sasl_log;
351         session_callbacks[0].context = conn;
352
353         session_callbacks[1].id = SASL_CB_PROXY_POLICY;
354         session_callbacks[1].proc = &slap_sasl_authorize;
355         session_callbacks[1].context = conn;
356
357         session_callbacks[2].id = SASL_CB_LIST_END;
358         session_callbacks[2].proc = NULL;
359         session_callbacks[2].context = NULL;
360
361         if( global_host == NULL ) {
362                 global_host = ldap_pvt_get_fqdn( NULL );
363         }
364
365         /* create new SASL context */
366         sc = sasl_server_new( "ldap", global_host, global_realm,
367                 session_callbacks, SASL_SECURITY_LAYER, &ctx );
368
369         if( sc != SASL_OK ) {
370                 Debug( LDAP_DEBUG_ANY, "sasl_server_new failed: %d\n",
371                         sc, 0, 0 );
372                 return -1;
373         }
374
375         conn->c_sasl_context = ctx;
376
377         if( sc == SASL_OK ) {
378                 sc = sasl_setprop( ctx,
379                         SASL_SEC_PROPS, &sasl_secprops );
380
381                 if( sc != SASL_OK ) {
382                         Debug( LDAP_DEBUG_ANY, "sasl_setprop failed: %d\n",
383                                 sc, 0, 0 );
384                         slap_sasl_close( conn );
385                         return -1;
386                 }
387         }
388
389         sc = slap_sasl_err2ldap( sc );
390 #endif
391         return sc;
392 }
393
394 int slap_sasl_external(
395         Connection *conn,
396         slap_ssf_t ssf,
397         const char *auth_id )
398 {
399 #ifdef HAVE_CYRUS_SASL
400         int sc;
401         sasl_conn_t *ctx = conn->c_sasl_context;
402         sasl_external_properties_t extprops;
403
404         if ( ctx == NULL ) {
405                 return LDAP_UNAVAILABLE;
406         }
407
408         memset( &extprops, '\0', sizeof(extprops) );
409         extprops.ssf = ssf;
410         extprops.auth_id = (char *) auth_id;
411
412         sc = sasl_setprop( ctx, SASL_SSF_EXTERNAL,
413                 (void *) &extprops );
414
415         if ( sc != SASL_OK ) {
416                 return LDAP_OTHER;
417         }
418 #endif
419
420         return LDAP_SUCCESS;
421 }
422
423 int slap_sasl_reset( Connection *conn )
424 {
425 #ifdef HAVE_CYRUS_SASL
426         sasl_conn_t *ctx = conn->c_sasl_context;
427
428         if( ctx != NULL ) {
429         }
430 #endif
431         /* must return "anonymous" */
432         return LDAP_SUCCESS;
433 }
434
435 char ** slap_sasl_mechs( Connection *conn )
436 {
437         char **mechs = NULL;
438
439 #ifdef HAVE_CYRUS_SASL
440         sasl_conn_t *ctx = conn->c_sasl_context;
441
442         if( ctx != NULL ) {
443                 int sc;
444                 char *mechstr;
445
446                 sc = sasl_listmech( ctx,
447                         NULL, NULL, ",", NULL,
448                         &mechstr, NULL, NULL );
449
450                 if( sc != SASL_OK ) {
451                         Debug( LDAP_DEBUG_ANY, "slap_sasl_listmech failed: %d\n",
452                                 sc, 0, 0 );
453                         return NULL;
454                 }
455
456                 mechs = str2charray( mechstr, "," );
457
458                 ch_free( mechstr );
459         }
460 #endif
461
462         return mechs;
463 }
464
465 int slap_sasl_close( Connection *conn )
466 {
467 #ifdef HAVE_CYRUS_SASL
468         sasl_conn_t *ctx = conn->c_sasl_context;
469
470         if( ctx != NULL ) {
471                 sasl_dispose( &ctx );
472         }
473
474         conn->c_sasl_context = NULL;
475
476         free( conn->c_sasl_extra );
477         conn->c_sasl_extra = NULL;
478 #endif
479
480         return LDAP_SUCCESS;
481 }
482
483 int slap_sasl_bind(
484     Connection          *conn,
485     Operation           *op,  
486     const char          *dn,  
487     const char          *ndn,
488     struct berval       *cred,
489         char                            **edn,
490         slap_ssf_t                      *ssfp )
491 {
492         int rc = 1;
493
494 #ifdef HAVE_CYRUS_SASL
495         sasl_conn_t *ctx = conn->c_sasl_context;
496         struct berval response;
497         unsigned reslen;
498         const char *errstr;
499         int sc;
500
501         Debug(LDAP_DEBUG_ARGS,
502           "==> sasl_bind: dn=\"%s\" mech=%s datalen=%d\n", dn,
503           conn->c_sasl_bind_in_progress ? "<continuing>":conn->c_sasl_bind_mech,
504           cred ? cred->bv_len : 0 );
505
506         if( ctx == NULL ) {
507                 send_ldap_result( conn, op, LDAP_UNAVAILABLE,
508                         NULL, "SASL unavailable on this session", NULL, NULL );
509                 return rc;
510         }
511
512         if ( !conn->c_sasl_bind_in_progress ) {
513                 sc = sasl_server_start( ctx,
514                         conn->c_sasl_bind_mech,
515                         cred->bv_val, cred->bv_len,
516                         (char **)&response.bv_val, &reslen, &errstr );
517
518         } else {
519                 sc = sasl_server_step( ctx,
520                         cred->bv_val, cred->bv_len,
521                         (char **)&response.bv_val, &reslen, &errstr );
522         }
523
524         response.bv_len = reslen;
525
526         if ( sc == SASL_OK ) {
527                 char *username = NULL;
528
529                 sc = sasl_getprop( ctx,
530                         SASL_USERNAME, (void **)&username );
531
532                 if ( sc != SASL_OK ) {
533                         Debug(LDAP_DEBUG_TRACE,
534                                 "slap_sasl_bind: getprop(USERNAME) failed!\n",
535                                 0, 0, 0);
536
537                         send_ldap_result( conn, op, rc = slap_sasl_err2ldap( sc ),
538                                 NULL, "no SASL username", NULL, NULL );
539
540                 } else {
541                         rc = slap_sasl_getdn( conn, username, edn, FLAG_GETDN_FINAL );
542
543                         if( rc == LDAP_SUCCESS ) {
544                                 int i;
545                                 sasl_ssf_t *ssf = NULL;
546                                 (void) sasl_getprop( ctx, SASL_SSF, (void *)&ssf );
547                                 *ssfp = ssf ? *ssf : 0;
548
549                                 if( *ssfp ) {
550                                         ldap_pvt_thread_mutex_lock( &conn->c_mutex );
551                                         conn->c_sasl_layers++;
552                                         ldap_pvt_thread_mutex_unlock( &conn->c_mutex );
553                                 }
554
555                                 /* Store the authorization DN as a subjectDN */
556                                 if ( *edn ) {
557                                         i = 2;
558                                         do {
559                                                 i++;
560                                                 (*edn)[i-3] = (*edn)[i];
561                                         } while( (*edn)[i] );
562                                 }
563
564                                 send_ldap_sasl( conn, op, rc,
565                                         NULL, NULL, NULL, NULL,
566                                         response.bv_len ? &response : NULL );
567
568                         } else {
569                                 send_ldap_result( conn, op, rc,
570                                         NULL, errstr, NULL, NULL );
571                         }
572                 }
573
574         } else if ( sc == SASL_CONTINUE ) {
575                 send_ldap_sasl( conn, op, rc = LDAP_SASL_BIND_IN_PROGRESS,
576                         NULL, NULL, NULL, NULL, &response );
577
578         } else {
579                 send_ldap_result( conn, op, rc = slap_sasl_err2ldap( sc ),
580                         NULL, errstr, NULL, NULL );
581         }
582
583         Debug(LDAP_DEBUG_TRACE, "<== slap_sasl_bind: rc=%d\n", rc, 0, 0);
584
585 #else
586         send_ldap_result( conn, op, rc = LDAP_UNAVAILABLE,
587                 NULL, "SASL not supported", NULL, NULL );
588 #endif
589
590         return rc;
591 }
592
593 char* slap_sasl_secprops( const char *in )
594 {
595 #ifdef HAVE_CYRUS_SASL
596         int rc = ldap_pvt_sasl_secprops( in, &sasl_secprops );
597
598         return rc == LDAP_SUCCESS ? NULL : "Invalid security properties";
599 #else
600         return "SASL not supported";
601 #endif
602 }