1 /*	$NetBSD: bind.c,v 1.1.1.3 2010/12/12 15:22:24 adam Exp $	*/
2 
3 /* bind.c - decode an ldap bind operation and pass it to a backend db */
4 /* OpenLDAP: pkg/ldap/servers/slapd/bind.c,v 1.201.2.6 2010/04/13 20:23:12 kurt Exp */
5 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
6  *
7  * Copyright 1998-2010 The OpenLDAP Foundation.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted only as authorized by the OpenLDAP
12  * Public License.
13  *
14  * A copy of this license is available in the file LICENSE in the
15  * top-level directory of the distribution or, alternatively, at
16  * <http://www.OpenLDAP.org/license.html>.
17  */
18 /* Portions Copyright (c) 1995 Regents of the University of Michigan.
19  * All rights reserved.
20  *
21  * Redistribution and use in source and binary forms are permitted
22  * provided that this notice is preserved and that due credit is given
23  * to the University of Michigan at Ann Arbor. The name of the University
24  * may not be used to endorse or promote products derived from this
25  * software without specific prior written permission. This software
26  * is provided ``as is'' without express or implied warranty.
27  */
28 
29 #include "portable.h"
30 
31 #include <stdio.h>
32 
33 #include <ac/string.h>
34 #include <ac/socket.h>
35 
36 #include "slap.h"
37 
38 int
39 do_bind(
40     Operation	*op,
41     SlapReply	*rs )
42 {
43 	BerElement *ber = op->o_ber;
44 	ber_int_t version;
45 	ber_tag_t method;
46 	struct berval mech = BER_BVNULL;
47 	struct berval dn = BER_BVNULL;
48 	ber_tag_t tag;
49 	Backend *be = NULL;
50 
51 	Debug( LDAP_DEBUG_TRACE, "%s do_bind\n",
52 		op->o_log_prefix, 0, 0 );
53 
54 	/*
55 	 * Force the connection to "anonymous" until bind succeeds.
56 	 */
57 	ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
58 	if ( op->o_conn->c_sasl_bind_in_progress ) {
59 		be = op->o_conn->c_authz_backend;
60 	}
61 	if ( !BER_BVISEMPTY( &op->o_conn->c_dn ) ) {
62 		/* log authorization identity demotion */
63 		Statslog( LDAP_DEBUG_STATS,
64 			"%s BIND anonymous mech=implicit ssf=0\n",
65 			op->o_log_prefix, 0, 0, 0, 0 );
66 	}
67 	connection2anonymous( op->o_conn );
68 	if ( op->o_conn->c_sasl_bind_in_progress ) {
69 		op->o_conn->c_authz_backend = be;
70 	}
71 	ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
72 	if ( !BER_BVISNULL( &op->o_dn ) ) {
73 		/* NOTE: temporarily wasting few bytes
74 		 * (until bind is completed), but saving
75 		 * a couple of ch_free() and ch_strdup("") */
76 		op->o_dn.bv_val[0] = '\0';
77 		op->o_dn.bv_len = 0;
78 	}
79 	if ( !BER_BVISNULL( &op->o_ndn ) ) {
80 		op->o_ndn.bv_val[0] = '\0';
81 		op->o_ndn.bv_len = 0;
82 	}
83 
84 	/*
85 	 * Parse the bind request.  It looks like this:
86 	 *
87 	 *	BindRequest ::= SEQUENCE {
88 	 *		version		INTEGER,		 -- version
89 	 *		name		DistinguishedName,	 -- dn
90 	 *		authentication	CHOICE {
91 	 *			simple		[0] OCTET STRING -- passwd
92 	 *			krbv42ldap	[1] OCTET STRING -- OBSOLETE
93 	 *			krbv42dsa	[2] OCTET STRING -- OBSOLETE
94 	 *			SASL		[3] SaslCredentials
95 	 *		}
96 	 *	}
97 	 *
98 	 *	SaslCredentials ::= SEQUENCE {
99 	 *		mechanism	    LDAPString,
100 	 *		credentials	    OCTET STRING OPTIONAL
101 	 *	}
102 	 */
103 
104 	tag = ber_scanf( ber, "{imt" /*}*/, &version, &dn, &method );
105 
106 	if ( tag == LBER_ERROR ) {
107 		Debug( LDAP_DEBUG_ANY, "%s do_bind: ber_scanf failed\n",
108 			op->o_log_prefix, 0, 0 );
109 		send_ldap_discon( op, rs, LDAP_PROTOCOL_ERROR, "decoding error" );
110 		rs->sr_err = SLAPD_DISCONNECT;
111 		goto cleanup;
112 	}
113 
114 	op->o_protocol = version;
115 	op->orb_method = method;
116 
117 	if( op->orb_method != LDAP_AUTH_SASL ) {
118 		tag = ber_scanf( ber, /*{*/ "m}", &op->orb_cred );
119 
120 	} else {
121 		tag = ber_scanf( ber, "{m" /*}*/, &mech );
122 
123 		if ( tag != LBER_ERROR ) {
124 			ber_len_t len;
125 			tag = ber_peek_tag( ber, &len );
126 
127 			if ( tag == LDAP_TAG_LDAPCRED ) {
128 				tag = ber_scanf( ber, "m", &op->orb_cred );
129 			} else {
130 				tag = LDAP_TAG_LDAPCRED;
131 				BER_BVZERO( &op->orb_cred );
132 			}
133 
134 			if ( tag != LBER_ERROR ) {
135 				tag = ber_scanf( ber, /*{{*/ "}}" );
136 			}
137 		}
138 	}
139 
140 	if ( tag == LBER_ERROR ) {
141 		Debug( LDAP_DEBUG_ANY, "%s do_bind: ber_scanf failed\n",
142 			op->o_log_prefix, 0, 0 );
143 		send_ldap_discon( op, rs, LDAP_PROTOCOL_ERROR, "decoding error" );
144 		rs->sr_err = SLAPD_DISCONNECT;
145 		goto cleanup;
146 	}
147 
148 	if( get_ctrls( op, rs, 1 ) != LDAP_SUCCESS ) {
149 		Debug( LDAP_DEBUG_ANY, "%s do_bind: get_ctrls failed\n",
150 			op->o_log_prefix, 0, 0 );
151 		goto cleanup;
152 	}
153 
154 	/* We use the tmpmemctx here because it speeds up normalization.
155 	 * However, we must dup with regular malloc when storing any
156 	 * resulting DNs in the op or conn structures.
157 	 */
158 	rs->sr_err = dnPrettyNormal( NULL, &dn, &op->o_req_dn, &op->o_req_ndn,
159 		op->o_tmpmemctx );
160 	if ( rs->sr_err != LDAP_SUCCESS ) {
161 		Debug( LDAP_DEBUG_ANY, "%s do_bind: invalid dn (%s)\n",
162 			op->o_log_prefix, dn.bv_val, 0 );
163 		send_ldap_error( op, rs, LDAP_INVALID_DN_SYNTAX, "invalid DN" );
164 		goto cleanup;
165 	}
166 
167 	Statslog( LDAP_DEBUG_STATS, "%s BIND dn=\"%s\" method=%ld\n",
168 	    op->o_log_prefix, op->o_req_dn.bv_val,
169 		(unsigned long) op->orb_method, 0, 0 );
170 
171 	if( op->orb_method == LDAP_AUTH_SASL ) {
172 		Debug( LDAP_DEBUG_TRACE, "do_bind: dn (%s) SASL mech %s\n",
173 			op->o_req_dn.bv_val, mech.bv_val, NULL );
174 
175 	} else {
176 		Debug( LDAP_DEBUG_TRACE,
177 			"do_bind: version=%ld dn=\"%s\" method=%ld\n",
178 			(unsigned long) version, op->o_req_dn.bv_val,
179 			(unsigned long) op->orb_method );
180 	}
181 
182 	if ( version < LDAP_VERSION_MIN || version > LDAP_VERSION_MAX ) {
183 		Debug( LDAP_DEBUG_ANY, "%s do_bind: unknown version=%ld\n",
184 			op->o_log_prefix, (unsigned long) version, 0 );
185 		send_ldap_error( op, rs, LDAP_PROTOCOL_ERROR,
186 			"requested protocol version not supported" );
187 		goto cleanup;
188 
189 	} else if (!( global_allows & SLAP_ALLOW_BIND_V2 ) &&
190 		version < LDAP_VERSION3 )
191 	{
192 		send_ldap_error( op, rs, LDAP_PROTOCOL_ERROR,
193 			"historical protocol version requested, use LDAPv3 instead" );
194 		goto cleanup;
195 	}
196 
197 	/*
198 	 * we set connection version regardless of whether bind succeeds or not.
199 	 */
200 	ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
201 	op->o_conn->c_protocol = version;
202 	ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
203 
204 	op->orb_mech = mech;
205 
206 	op->o_bd = frontendDB;
207 	rs->sr_err = frontendDB->be_bind( op, rs );
208 
209 cleanup:
210 	if ( rs->sr_err == LDAP_SUCCESS ) {
211 		if ( op->orb_method != LDAP_AUTH_SASL ) {
212 			ber_dupbv( &op->o_conn->c_authmech, &mech );
213 		}
214 		op->o_conn->c_authtype = op->orb_method;
215 	}
216 
217 	if( !BER_BVISNULL( &op->o_req_dn ) ) {
218 		slap_sl_free( op->o_req_dn.bv_val, op->o_tmpmemctx );
219 		BER_BVZERO( &op->o_req_dn );
220 	}
221 	if( !BER_BVISNULL( &op->o_req_ndn ) ) {
222 		slap_sl_free( op->o_req_ndn.bv_val, op->o_tmpmemctx );
223 		BER_BVZERO( &op->o_req_ndn );
224 	}
225 
226 	return rs->sr_err;
227 }
228 
229 int
230 fe_op_bind( Operation *op, SlapReply *rs )
231 {
232 	BackendDB	*bd = op->o_bd;
233 
234 	/* check for inappropriate controls */
235 	if( get_manageDSAit( op ) == SLAP_CONTROL_CRITICAL ) {
236 		send_ldap_error( op, rs,
237 			LDAP_UNAVAILABLE_CRITICAL_EXTENSION,
238 			"manageDSAit control inappropriate" );
239 		goto cleanup;
240 	}
241 
242 	if ( op->orb_method == LDAP_AUTH_SASL ) {
243 		if ( op->o_protocol < LDAP_VERSION3 ) {
244 			Debug( LDAP_DEBUG_ANY, "do_bind: sasl with LDAPv%ld\n",
245 				(unsigned long)op->o_protocol, 0, 0 );
246 			send_ldap_discon( op, rs,
247 				LDAP_PROTOCOL_ERROR, "SASL bind requires LDAPv3" );
248 			rs->sr_err = SLAPD_DISCONNECT;
249 			goto cleanup;
250 		}
251 
252 		if( BER_BVISNULL( &op->orb_mech ) || BER_BVISEMPTY( &op->orb_mech ) ) {
253 			Debug( LDAP_DEBUG_ANY,
254 				"do_bind: no sasl mechanism provided\n",
255 				0, 0, 0 );
256 			send_ldap_error( op, rs, LDAP_AUTH_METHOD_NOT_SUPPORTED,
257 				"no SASL mechanism provided" );
258 			goto cleanup;
259 		}
260 
261 		/* check restrictions */
262 		if( backend_check_restrictions( op, rs, &op->orb_mech ) != LDAP_SUCCESS ) {
263 			send_ldap_result( op, rs );
264 			goto cleanup;
265 		}
266 
267 		ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
268 		if ( op->o_conn->c_sasl_bind_in_progress ) {
269 			if( !bvmatch( &op->o_conn->c_sasl_bind_mech, &op->orb_mech ) ) {
270 				/* mechanism changed between bind steps */
271 				slap_sasl_reset(op->o_conn);
272 			}
273 		} else {
274 			ber_dupbv(&op->o_conn->c_sasl_bind_mech, &op->orb_mech);
275 		}
276 
277 		/* Set the bindop for the benefit of in-directory SASL lookups */
278 		op->o_conn->c_sasl_bindop = op;
279 
280 		ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
281 
282 		rs->sr_err = slap_sasl_bind( op, rs );
283 
284 		goto cleanup;
285 
286 	} else {
287 		/* Not SASL, cancel any in-progress bind */
288 		ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
289 
290 		if ( !BER_BVISNULL( &op->o_conn->c_sasl_bind_mech ) ) {
291 			free( op->o_conn->c_sasl_bind_mech.bv_val );
292 			BER_BVZERO( &op->o_conn->c_sasl_bind_mech );
293 		}
294 		op->o_conn->c_sasl_bind_in_progress = 0;
295 
296 		slap_sasl_reset( op->o_conn );
297 		ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
298 	}
299 
300 	if ( op->orb_method == LDAP_AUTH_SIMPLE ) {
301 		BER_BVSTR( &op->orb_mech, "SIMPLE" );
302 		/* accept "anonymous" binds */
303 		if ( BER_BVISEMPTY( &op->orb_cred ) || BER_BVISEMPTY( &op->o_req_ndn ) ) {
304 			rs->sr_err = LDAP_SUCCESS;
305 
306 			if( !BER_BVISEMPTY( &op->orb_cred ) &&
307 				!( global_allows & SLAP_ALLOW_BIND_ANON_CRED ))
308 			{
309 				/* cred is not empty, disallow */
310 				rs->sr_err = LDAP_INVALID_CREDENTIALS;
311 
312 			} else if ( !BER_BVISEMPTY( &op->o_req_ndn ) &&
313 				!( global_allows & SLAP_ALLOW_BIND_ANON_DN ))
314 			{
315 				/* DN is not empty, disallow */
316 				rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
317 				rs->sr_text =
318 					"unauthenticated bind (DN with no password) disallowed";
319 
320 			} else if ( global_disallows & SLAP_DISALLOW_BIND_ANON ) {
321 				/* disallow */
322 				rs->sr_err = LDAP_INAPPROPRIATE_AUTH;
323 				rs->sr_text = "anonymous bind disallowed";
324 
325 			} else {
326 				backend_check_restrictions( op, rs, &op->orb_mech );
327 			}
328 
329 			/*
330 			 * we already forced connection to "anonymous",
331 			 * just need to send success
332 			 */
333 			send_ldap_result( op, rs );
334 			Debug( LDAP_DEBUG_TRACE, "do_bind: v%d anonymous bind\n",
335 				op->o_protocol, 0, 0 );
336 			goto cleanup;
337 
338 		} else if ( global_disallows & SLAP_DISALLOW_BIND_SIMPLE ) {
339 			/* disallow simple authentication */
340 			rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
341 			rs->sr_text = "unwilling to perform simple authentication";
342 
343 			send_ldap_result( op, rs );
344 			Debug( LDAP_DEBUG_TRACE,
345 				"do_bind: v%d simple bind(%s) disallowed\n",
346 				op->o_protocol, op->o_req_ndn.bv_val, 0 );
347 			goto cleanup;
348 		}
349 
350 	} else {
351 		rs->sr_err = LDAP_AUTH_METHOD_NOT_SUPPORTED;
352 		rs->sr_text = "unknown authentication method";
353 
354 		send_ldap_result( op, rs );
355 		Debug( LDAP_DEBUG_TRACE,
356 			"do_bind: v%d unknown authentication method (%d)\n",
357 			op->o_protocol, op->orb_method, 0 );
358 		goto cleanup;
359 	}
360 
361 	/*
362 	 * We could be serving multiple database backends.  Select the
363 	 * appropriate one, or send a referral to our "referral server"
364 	 * if we don't hold it.
365 	 */
366 
367 	if ( (op->o_bd = select_backend( &op->o_req_ndn, 0 )) == NULL ) {
368 		/* don't return referral for bind requests */
369 		/* noSuchObject is not allowed to be returned by bind */
370 		rs->sr_err = LDAP_INVALID_CREDENTIALS;
371 		op->o_bd = bd;
372 		send_ldap_result( op, rs );
373 		goto cleanup;
374 	}
375 
376 	/* check restrictions */
377 	if( backend_check_restrictions( op, rs, NULL ) != LDAP_SUCCESS ) {
378 		send_ldap_result( op, rs );
379 		goto cleanup;
380 	}
381 
382 	if( op->o_bd->be_bind ) {
383 		op->o_conn->c_authz_cookie = NULL;
384 
385 		rs->sr_err = (op->o_bd->be_bind)( op, rs );
386 
387 		if ( rs->sr_err == 0 ) {
388 			(void)fe_op_bind_success( op, rs );
389 
390 		} else if ( !BER_BVISNULL( &op->orb_edn ) ) {
391 			free( op->orb_edn.bv_val );
392 			BER_BVZERO( &op->orb_edn );
393 		}
394 
395 	} else {
396 		send_ldap_error( op, rs, LDAP_UNWILLING_TO_PERFORM,
397 			"operation not supported within naming context" );
398 	}
399 
400 cleanup:;
401 	op->o_bd = bd;
402 	return rs->sr_err;
403 }
404 
405 int
406 fe_op_bind_success( Operation *op, SlapReply *rs )
407 {
408 	ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
409 
410 	if( op->o_conn->c_authz_backend == NULL ) {
411 		op->o_conn->c_authz_backend = op->o_bd;
412 	}
413 
414 	/* be_bind returns regular/global edn */
415 	if( !BER_BVISEMPTY( &op->orb_edn ) ) {
416 		op->o_conn->c_dn = op->orb_edn;
417 	} else {
418 		ber_dupbv(&op->o_conn->c_dn, &op->o_req_dn);
419 	}
420 
421 	ber_dupbv( &op->o_conn->c_ndn, &op->o_req_ndn );
422 
423 	if( !BER_BVISEMPTY( &op->o_conn->c_dn ) ) {
424 		ber_len_t max = sockbuf_max_incoming_auth;
425 		ber_sockbuf_ctrl( op->o_conn->c_sb,
426 			LBER_SB_OPT_SET_MAX_INCOMING, &max );
427 	}
428 
429 	/* log authorization identity */
430 	Statslog( LDAP_DEBUG_STATS,
431 		"%s BIND dn=\"%s\" mech=%s ssf=0\n",
432 		op->o_log_prefix,
433 		op->o_conn->c_dn.bv_val, op->orb_mech.bv_val, 0, 0 );
434 
435 	Debug( LDAP_DEBUG_TRACE,
436 		"do_bind: v%d bind: \"%s\" to \"%s\"\n",
437 		op->o_protocol, op->o_req_dn.bv_val, op->o_conn->c_dn.bv_val );
438 
439 	ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
440 
441 	/* send this here to avoid a race condition */
442 	send_ldap_result( op, rs );
443 
444 	return LDAP_SUCCESS;
445 }
446