xref: /freebsd/crypto/heimdal/lib/krb5/keytab.c (revision ed549cb0c53f8438c52593ce811f6fcc812248e9)
1 /*
2  * Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "krb5_locl.h"
35 
36 /**
37  * @page krb5_keytab_intro The keytab handing functions
38  * @section section_krb5_keytab Kerberos Keytabs
39  *
40  * See the library functions here: @ref krb5_keytab
41  *
42  * Keytabs are long term key storage for servers, their equvalment of
43  * password files.
44  *
45  * Normally the only function that useful for server are to specify
46  * what keytab to use to other core functions like krb5_rd_req()
47  * krb5_kt_resolve(), and krb5_kt_close().
48  *
49  * @subsection krb5_keytab_names Keytab names
50  *
51  * A keytab name is on the form type:residual. The residual part is
52  * specific to each keytab-type.
53  *
54  * When a keytab-name is resolved, the type is matched with an internal
55  * list of keytab types. If there is no matching keytab type,
56  * the default keytab is used. The current default type is FILE.
57  *
58  * The default value can be changed in the configuration file
59  * /etc/krb5.conf by setting the variable
60  * [defaults]default_keytab_name.
61  *
62  * The keytab types that are implemented in Heimdal are:
63  * - file
64  *   store the keytab in a file, the type's name is FILE .  The
65  *   residual part is a filename. For compatibility with other
66  *   Kerberos implemtation WRFILE and JAVA14 is also accepted.  WRFILE
67  *   has the same format as FILE. JAVA14 have a format that is
68  *   compatible with older versions of MIT kerberos and SUN's Java
69  *   based installation.  They store a truncted kvno, so when the knvo
70  *   excess 255, they are truncted in this format.
71  *
72  * - keytab
73  *   store the keytab in a AFS keyfile (usually /usr/afs/etc/KeyFile ),
74  *   the type's name is AFSKEYFILE. The residual part is a filename.
75  *
76  * - memory
77  *   The keytab is stored in a memory segment. This allows sensitive
78  *   and/or temporary data not to be stored on disk. The type's name
79  *   is MEMORY. Each MEMORY keytab is referenced counted by and
80  *   opened by the residual name, so two handles can point to the
81  *   same memory area.  When the last user closes using krb5_kt_close()
82  *   the keytab, the keys in they keytab is memset() to zero and freed
83  *   and can no longer be looked up by name.
84  *
85  *
86  * @subsection krb5_keytab_example Keytab example
87  *
88  *  This is a minimalistic version of ktutil.
89  *
90  * @code
91 int
92 main (int argc, char **argv)
93 {
94     krb5_context context;
95     krb5_keytab keytab;
96     krb5_kt_cursor cursor;
97     krb5_keytab_entry entry;
98     krb5_error_code ret;
99     char *principal;
100 
101     if (krb5_init_context (&context) != 0)
102 	errx(1, "krb5_context");
103 
104     ret = krb5_kt_default (context, &keytab);
105     if (ret)
106 	krb5_err(context, 1, ret, "krb5_kt_default");
107 
108     ret = krb5_kt_start_seq_get(context, keytab, &cursor);
109     if (ret)
110 	krb5_err(context, 1, ret, "krb5_kt_start_seq_get");
111     while((ret = krb5_kt_next_entry(context, keytab, &entry, &cursor)) == 0){
112 	krb5_unparse_name(context, entry.principal, &principal);
113 	printf("principal: %s\n", principal);
114 	free(principal);
115 	krb5_kt_free_entry(context, &entry);
116     }
117     ret = krb5_kt_end_seq_get(context, keytab, &cursor);
118     if (ret)
119 	krb5_err(context, 1, ret, "krb5_kt_end_seq_get");
120     ret = krb5_kt_close(context, keytab);
121     if (ret)
122 	krb5_err(context, 1, ret, "krb5_kt_close");
123     krb5_free_context(context);
124     return 0;
125 }
126  * @endcode
127  *
128  */
129 
130 
131 /**
132  * Register a new keytab backend.
133  *
134  * @param context a Keberos context.
135  * @param ops a backend to register.
136  *
137  * @return Return an error code or 0, see krb5_get_error_message().
138  *
139  * @ingroup krb5_keytab
140  */
141 
142 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_register(krb5_context context,const krb5_kt_ops * ops)143 krb5_kt_register(krb5_context context,
144 		 const krb5_kt_ops *ops)
145 {
146     struct krb5_keytab_data *tmp;
147 
148     if (strlen(ops->prefix) > KRB5_KT_PREFIX_MAX_LEN - 1) {
149 	krb5_set_error_message(context, KRB5_KT_BADNAME,
150 			       N_("can't register cache type, prefix too long", ""));
151 	return KRB5_KT_BADNAME;
152     }
153 
154     tmp = realloc(context->kt_types,
155 		  (context->num_kt_types + 1) * sizeof(*context->kt_types));
156     if(tmp == NULL) {
157 	krb5_set_error_message(context, ENOMEM,
158 			       N_("malloc: out of memory", ""));
159 	return ENOMEM;
160     }
161     memcpy(&tmp[context->num_kt_types], ops,
162 	   sizeof(tmp[context->num_kt_types]));
163     context->kt_types = tmp;
164     context->num_kt_types++;
165     return 0;
166 }
167 
168 static const char *
keytab_name(const char * name,const char ** type,size_t * type_len)169 keytab_name(const char *name, const char **type, size_t *type_len)
170 {
171     const char *residual;
172 
173     residual = strchr(name, ':');
174 
175     if (residual == NULL ||
176 	name[0] == '/'
177 #ifdef _WIN32
178         /* Avoid treating <drive>:<path> as a keytab type
179          * specification */
180         || name + 1 == residual
181 #endif
182         ) {
183 
184         *type = "FILE";
185         *type_len = strlen(*type);
186         residual = name;
187     } else {
188         *type = name;
189         *type_len = residual - name;
190         residual++;
191     }
192 
193     return residual;
194 }
195 
196 /**
197  * Resolve the keytab name (of the form `type:residual') in `name'
198  * into a keytab in `id'.
199  *
200  * @param context a Keberos context.
201  * @param name name to resolve
202  * @param id resulting keytab, free with krb5_kt_close().
203  *
204  * @return Return an error code or 0, see krb5_get_error_message().
205  *
206  * @ingroup krb5_keytab
207  */
208 
209 
210 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_resolve(krb5_context context,const char * name,krb5_keytab * id)211 krb5_kt_resolve(krb5_context context,
212 		const char *name,
213 		krb5_keytab *id)
214 {
215     krb5_keytab k;
216     int i;
217     const char *type, *residual;
218     size_t type_len;
219     krb5_error_code ret;
220 
221     residual = keytab_name(name, &type, &type_len);
222 
223     for(i = 0; i < context->num_kt_types; i++) {
224 	if(strncasecmp(type, context->kt_types[i].prefix, type_len) == 0)
225 	    break;
226     }
227     if(i == context->num_kt_types) {
228 	krb5_set_error_message(context, KRB5_KT_UNKNOWN_TYPE,
229 			       N_("unknown keytab type %.*s", "type"),
230 			       (int)type_len, type);
231 	return KRB5_KT_UNKNOWN_TYPE;
232     }
233 
234     k = malloc (sizeof(*k));
235     if (k == NULL) {
236 	krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
237 	return ENOMEM;
238     }
239     memcpy(k, &context->kt_types[i], sizeof(*k));
240     k->data = NULL;
241     ret = (*k->resolve)(context, residual, k);
242     if(ret) {
243 	free(k);
244 	k = NULL;
245     }
246     *id = k;
247     return ret;
248 }
249 
250 /**
251  * copy the name of the default keytab into `name'.
252  *
253  * @param context a Keberos context.
254  * @param name buffer where the name will be written
255  * @param namesize length of name
256  *
257  * @return Return an error code or 0, see krb5_get_error_message().
258  *
259  * @ingroup krb5_keytab
260  */
261 
262 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_default_name(krb5_context context,char * name,size_t namesize)263 krb5_kt_default_name(krb5_context context, char *name, size_t namesize)
264 {
265     if (strlcpy (name, context->default_keytab, namesize) >= namesize) {
266 	krb5_clear_error_message (context);
267 	return KRB5_CONFIG_NOTENUFSPACE;
268     }
269     return 0;
270 }
271 
272 /**
273  * Copy the name of the default modify keytab into `name'.
274  *
275  * @param context a Keberos context.
276  * @param name buffer where the name will be written
277  * @param namesize length of name
278  *
279  * @return Return an error code or 0, see krb5_get_error_message().
280  *
281  * @ingroup krb5_keytab
282  */
283 
284 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_default_modify_name(krb5_context context,char * name,size_t namesize)285 krb5_kt_default_modify_name(krb5_context context, char *name, size_t namesize)
286 {
287     const char *kt = NULL;
288     if(context->default_keytab_modify == NULL) {
289 	if(strncasecmp(context->default_keytab, "ANY:", 4) != 0)
290 	    kt = context->default_keytab;
291 	else {
292 	    size_t len = strcspn(context->default_keytab + 4, ",");
293 	    if(len >= namesize) {
294 		krb5_clear_error_message(context);
295 		return KRB5_CONFIG_NOTENUFSPACE;
296 	    }
297 	    strlcpy(name, context->default_keytab + 4, namesize);
298 	    name[len] = '\0';
299 	    return 0;
300 	}
301     } else
302 	kt = context->default_keytab_modify;
303     if (strlcpy (name, kt, namesize) >= namesize) {
304 	krb5_clear_error_message (context);
305 	return KRB5_CONFIG_NOTENUFSPACE;
306     }
307     return 0;
308 }
309 
310 /**
311  * Set `id' to the default keytab.
312  *
313  * @param context a Keberos context.
314  * @param id the new default keytab.
315  *
316  * @return Return an error code or 0, see krb5_get_error_message().
317  *
318  * @ingroup krb5_keytab
319  */
320 
321 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_default(krb5_context context,krb5_keytab * id)322 krb5_kt_default(krb5_context context, krb5_keytab *id)
323 {
324     return krb5_kt_resolve (context, context->default_keytab, id);
325 }
326 
327 /**
328  * Read the key identified by `(principal, vno, enctype)' from the
329  * keytab in `keyprocarg' (the default if == NULL) into `*key'.
330  *
331  * @param context a Keberos context.
332  * @param keyprocarg
333  * @param principal
334  * @param vno
335  * @param enctype
336  * @param key
337  *
338  * @return Return an error code or 0, see krb5_get_error_message().
339  *
340  * @ingroup krb5_keytab
341  */
342 
343 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_read_service_key(krb5_context context,krb5_pointer keyprocarg,krb5_principal principal,krb5_kvno vno,krb5_enctype enctype,krb5_keyblock ** key)344 krb5_kt_read_service_key(krb5_context context,
345 			 krb5_pointer keyprocarg,
346 			 krb5_principal principal,
347 			 krb5_kvno vno,
348 			 krb5_enctype enctype,
349 			 krb5_keyblock **key)
350 {
351     krb5_keytab keytab = NULL; /* Quiet lint */
352     krb5_keytab_entry entry;
353     krb5_error_code ret;
354 
355     memset(&entry, 0, sizeof(entry));
356     if (keyprocarg)
357 	ret = krb5_kt_resolve (context, keyprocarg, &keytab);
358     else
359 	ret = krb5_kt_default (context, &keytab);
360 
361     if (ret)
362 	return ret;
363 
364     ret = krb5_kt_get_entry (context, keytab, principal, vno, enctype, &entry);
365     if (ret == 0) {
366         ret = krb5_copy_keyblock (context, &entry.keyblock, key);
367         krb5_kt_free_entry(context, &entry);
368     }
369     krb5_kt_close (context, keytab);
370     return ret;
371 }
372 
373 /**
374  * Return the type of the `keytab' in the string `prefix of length
375  * `prefixsize'.
376  *
377  * @param context a Keberos context.
378  * @param keytab the keytab to get the prefix for
379  * @param prefix prefix buffer
380  * @param prefixsize length of prefix buffer
381  *
382  * @return Return an error code or 0, see krb5_get_error_message().
383  *
384  * @ingroup krb5_keytab
385  */
386 
387 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_get_type(krb5_context context,krb5_keytab keytab,char * prefix,size_t prefixsize)388 krb5_kt_get_type(krb5_context context,
389 		 krb5_keytab keytab,
390 		 char *prefix,
391 		 size_t prefixsize)
392 {
393     strlcpy(prefix, keytab->prefix, prefixsize);
394     return 0;
395 }
396 
397 /**
398  * Retrieve the name of the keytab `keytab' into `name', `namesize'
399  *
400  * @param context a Keberos context.
401  * @param keytab the keytab to get the name for.
402  * @param name name buffer.
403  * @param namesize size of name buffer.
404  *
405  * @return Return an error code or 0, see krb5_get_error_message().
406  *
407  * @ingroup krb5_keytab
408  */
409 
410 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_get_name(krb5_context context,krb5_keytab keytab,char * name,size_t namesize)411 krb5_kt_get_name(krb5_context context,
412 		 krb5_keytab keytab,
413 		 char *name,
414 		 size_t namesize)
415 {
416     return (*keytab->get_name)(context, keytab, name, namesize);
417 }
418 
419 /**
420  * Retrieve the full name of the keytab `keytab' and store the name in
421  * `str'.
422  *
423  * @param context a Keberos context.
424  * @param keytab keytab to get name for.
425  * @param str the name of the keytab name, usee krb5_xfree() to free
426  *        the string.  On error, *str is set to NULL.
427  *
428  * @return Return an error code or 0, see krb5_get_error_message().
429  *
430  * @ingroup krb5_keytab
431  */
432 
433 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_get_full_name(krb5_context context,krb5_keytab keytab,char ** str)434 krb5_kt_get_full_name(krb5_context context,
435 		      krb5_keytab keytab,
436 		      char **str)
437 {
438     char type[KRB5_KT_PREFIX_MAX_LEN];
439     char name[MAXPATHLEN];
440     krb5_error_code ret;
441 
442     *str = NULL;
443 
444     ret = krb5_kt_get_type(context, keytab, type, sizeof(type));
445     if (ret)
446 	return ret;
447 
448     ret = krb5_kt_get_name(context, keytab, name, sizeof(name));
449     if (ret)
450 	return ret;
451 
452     if (asprintf(str, "%s:%s", type, name) == -1) {
453 	krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
454 	*str = NULL;
455 	return ENOMEM;
456     }
457 
458     return 0;
459 }
460 
461 /**
462  * Finish using the keytab in `id'.  All resources will be released,
463  * even on errors.
464  *
465  * @param context a Keberos context.
466  * @param id keytab to close.
467  *
468  * @return Return an error code or 0, see krb5_get_error_message().
469  *
470  * @ingroup krb5_keytab
471  */
472 
473 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_close(krb5_context context,krb5_keytab id)474 krb5_kt_close(krb5_context context,
475 	      krb5_keytab id)
476 {
477     krb5_error_code ret = 0;
478 
479     if (id) {
480         ret = (id->close)(context, id);
481         memset(id, 0, sizeof(*id));
482         free(id);
483     }
484     return ret;
485 }
486 
487 /**
488  * Destroy (remove) the keytab in `id'.  All resources will be released,
489  * even on errors, does the equvalment of krb5_kt_close() on the resources.
490  *
491  * @param context a Keberos context.
492  * @param id keytab to destroy.
493  *
494  * @return Return an error code or 0, see krb5_get_error_message().
495  *
496  * @ingroup krb5_keytab
497  */
498 
499 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_destroy(krb5_context context,krb5_keytab id)500 krb5_kt_destroy(krb5_context context,
501 		krb5_keytab id)
502 {
503     krb5_error_code ret;
504 
505     ret = (*id->destroy)(context, id);
506     krb5_kt_close(context, id);
507     return ret;
508 }
509 
510 /*
511  * Match any aliases in keytab `entry' with `principal'.
512  */
513 
514 static krb5_boolean
compare_aliseses(krb5_context context,krb5_keytab_entry * entry,krb5_const_principal principal)515 compare_aliseses(krb5_context context,
516 		 krb5_keytab_entry *entry,
517 		 krb5_const_principal principal)
518 {
519     unsigned int i;
520     if (entry->aliases == NULL)
521 	return FALSE;
522     for (i = 0; i < entry->aliases->len; i++)
523 	if (krb5_principal_compare(context, &entry->aliases->val[i], principal))
524 	    return TRUE;
525     return FALSE;
526 }
527 
528 /**
529  * Compare `entry' against `principal, vno, enctype'.
530  * Any of `principal, vno, enctype' might be 0 which acts as a wildcard.
531  * Return TRUE if they compare the same, FALSE otherwise.
532  *
533  * @param context a Keberos context.
534  * @param entry an entry to match with.
535  * @param principal principal to match, NULL matches all principals.
536  * @param vno key version to match, 0 matches all key version numbers.
537  * @param enctype encryption type to match, 0 matches all encryption types.
538  *
539  * @return Return TRUE or match, FALSE if not matched.
540  *
541  * @ingroup krb5_keytab
542  */
543 
544 KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL
krb5_kt_compare(krb5_context context,krb5_keytab_entry * entry,krb5_const_principal principal,krb5_kvno vno,krb5_enctype enctype)545 krb5_kt_compare(krb5_context context,
546 		krb5_keytab_entry *entry,
547 		krb5_const_principal principal,
548 		krb5_kvno vno,
549 		krb5_enctype enctype)
550 {
551     if(principal != NULL &&
552        !(krb5_principal_compare(context, entry->principal, principal) ||
553 	 compare_aliseses(context, entry, principal)))
554 	return FALSE;
555     if(vno && vno != entry->vno)
556 	return FALSE;
557     if(enctype && enctype != entry->keyblock.keytype)
558 	return FALSE;
559     return TRUE;
560 }
561 
562 krb5_error_code
_krb5_kt_principal_not_found(krb5_context context,krb5_error_code ret,krb5_keytab id,krb5_const_principal principal,krb5_enctype enctype,int kvno)563 _krb5_kt_principal_not_found(krb5_context context,
564 			     krb5_error_code ret,
565 			     krb5_keytab id,
566 			     krb5_const_principal principal,
567 			     krb5_enctype enctype,
568 			     int kvno)
569 {
570     char princ[256], kvno_str[25], *kt_name;
571     char *enctype_str = NULL;
572 
573     krb5_unparse_name_fixed (context, principal, princ, sizeof(princ));
574     krb5_kt_get_full_name (context, id, &kt_name);
575     krb5_enctype_to_string(context, enctype, &enctype_str);
576 
577     if (kvno)
578 	snprintf(kvno_str, sizeof(kvno_str), "(kvno %d)", kvno);
579     else
580 	kvno_str[0] = '\0';
581 
582     krb5_set_error_message (context, ret,
583 			    N_("Failed to find %s%s in keytab %s (%s)",
584 			       "principal, kvno, keytab file, enctype"),
585 			    princ,
586 			    kvno_str,
587 			    kt_name ? kt_name : "unknown keytab",
588 			    enctype_str ? enctype_str : "unknown enctype");
589     free(kt_name);
590     free(enctype_str);
591     return ret;
592 }
593 
594 
595 /**
596  * Retrieve the keytab entry for `principal, kvno, enctype' into `entry'
597  * from the keytab `id'. Matching is done like krb5_kt_compare().
598  *
599  * @param context a Keberos context.
600  * @param id a keytab.
601  * @param principal principal to match, NULL matches all principals.
602  * @param kvno key version to match, 0 matches all key version numbers.
603  * @param enctype encryption type to match, 0 matches all encryption types.
604  * @param entry the returned entry, free with krb5_kt_free_entry().
605  *
606  * @return Return an error code or 0, see krb5_get_error_message().
607  *
608  * @ingroup krb5_keytab
609  */
610 
611 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_get_entry(krb5_context context,krb5_keytab id,krb5_const_principal principal,krb5_kvno kvno,krb5_enctype enctype,krb5_keytab_entry * entry)612 krb5_kt_get_entry(krb5_context context,
613 		  krb5_keytab id,
614 		  krb5_const_principal principal,
615 		  krb5_kvno kvno,
616 		  krb5_enctype enctype,
617 		  krb5_keytab_entry *entry)
618 {
619     krb5_keytab_entry tmp;
620     krb5_error_code ret;
621     krb5_kt_cursor cursor;
622 
623     if(id->get)
624 	return (*id->get)(context, id, principal, kvno, enctype, entry);
625 
626     memset(&tmp, 0, sizeof(tmp));
627     ret = krb5_kt_start_seq_get (context, id, &cursor);
628     if (ret) {
629 	/* This is needed for krb5_verify_init_creds, but keep error
630 	 * string from previous error for the human. */
631 	context->error_code = KRB5_KT_NOTFOUND;
632 	return KRB5_KT_NOTFOUND;
633     }
634 
635     entry->vno = 0;
636     while (krb5_kt_next_entry(context, id, &tmp, &cursor) == 0) {
637 	if (krb5_kt_compare(context, &tmp, principal, 0, enctype)) {
638 	    /* the file keytab might only store the lower 8 bits of
639 	       the kvno, so only compare those bits */
640 	    if (kvno == tmp.vno
641 		|| (tmp.vno < 256 && kvno % 256 == tmp.vno)) {
642 		krb5_kt_copy_entry_contents (context, &tmp, entry);
643 		krb5_kt_free_entry (context, &tmp);
644 		krb5_kt_end_seq_get(context, id, &cursor);
645 		return 0;
646 	    } else if (kvno == 0 && tmp.vno > entry->vno) {
647 		if (entry->vno)
648 		    krb5_kt_free_entry (context, entry);
649 		krb5_kt_copy_entry_contents (context, &tmp, entry);
650 	    }
651 	}
652 	krb5_kt_free_entry(context, &tmp);
653     }
654     krb5_kt_end_seq_get (context, id, &cursor);
655     if (entry->vno == 0)
656 	return _krb5_kt_principal_not_found(context, KRB5_KT_NOTFOUND,
657 					    id, principal, enctype, kvno);
658     return 0;
659 }
660 
661 /**
662  * Copy the contents of `in' into `out'.
663  *
664  * @param context a Keberos context.
665  * @param in the keytab entry to copy.
666  * @param out the copy of the keytab entry, free with krb5_kt_free_entry().
667  *
668  * @return Return an error code or 0, see krb5_get_error_message().
669  *
670  * @ingroup krb5_keytab
671  */
672 
673 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_copy_entry_contents(krb5_context context,const krb5_keytab_entry * in,krb5_keytab_entry * out)674 krb5_kt_copy_entry_contents(krb5_context context,
675 			    const krb5_keytab_entry *in,
676 			    krb5_keytab_entry *out)
677 {
678     krb5_error_code ret;
679 
680     memset(out, 0, sizeof(*out));
681 
682     ret = krb5_copy_principal (context, in->principal, &out->principal);
683     if (ret)
684 	return ret;
685     ret = krb5_copy_keyblock_contents (context,
686 				       &in->keyblock,
687 				       &out->keyblock);
688     if (ret) {
689         krb5_free_principal(context, out->principal);
690         memset(out, 0, sizeof(*out));
691         return ret;
692     }
693     out->vno = in->vno;
694     out->timestamp = in->timestamp;
695     return 0;
696 }
697 
698 /**
699  * Free the contents of `entry'.
700  *
701  * @param context a Keberos context.
702  * @param entry the entry to free
703  *
704  * @return Return an error code or 0, see krb5_get_error_message().
705  *
706  * @ingroup krb5_keytab
707  */
708 
709 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_free_entry(krb5_context context,krb5_keytab_entry * entry)710 krb5_kt_free_entry(krb5_context context,
711 		   krb5_keytab_entry *entry)
712 {
713     krb5_free_principal (context, entry->principal);
714     krb5_free_keyblock_contents (context, &entry->keyblock);
715     memset(entry, 0, sizeof(*entry));
716     return 0;
717 }
718 
719 /**
720  * Set `cursor' to point at the beginning of `id'.
721  *
722  * @param context a Keberos context.
723  * @param id a keytab.
724  * @param cursor a newly allocated cursor, free with krb5_kt_end_seq_get().
725  *
726  * @return Return an error code or 0, see krb5_get_error_message().
727  *
728  * @ingroup krb5_keytab
729  */
730 
731 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_start_seq_get(krb5_context context,krb5_keytab id,krb5_kt_cursor * cursor)732 krb5_kt_start_seq_get(krb5_context context,
733 		      krb5_keytab id,
734 		      krb5_kt_cursor *cursor)
735 {
736     if(id->start_seq_get == NULL) {
737 	krb5_set_error_message(context, HEIM_ERR_OPNOTSUPP,
738 			       N_("start_seq_get is not supported "
739 				  "in the %s keytab type", ""),
740 			       id->prefix);
741 	return HEIM_ERR_OPNOTSUPP;
742     }
743     return (*id->start_seq_get)(context, id, cursor);
744 }
745 
746 /**
747  * Get the next entry from keytab, advance the cursor.  On last entry
748  * the function will return KRB5_KT_END.
749  *
750  * @param context a Keberos context.
751  * @param id a keytab.
752  * @param entry the returned entry, free with krb5_kt_free_entry().
753  * @param cursor the cursor of the iteration.
754  *
755  * @return Return an error code or 0, see krb5_get_error_message().
756  *
757  * @ingroup krb5_keytab
758  */
759 
760 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_next_entry(krb5_context context,krb5_keytab id,krb5_keytab_entry * entry,krb5_kt_cursor * cursor)761 krb5_kt_next_entry(krb5_context context,
762 		   krb5_keytab id,
763 		   krb5_keytab_entry *entry,
764 		   krb5_kt_cursor *cursor)
765 {
766     if(id->next_entry == NULL) {
767 	krb5_set_error_message(context, HEIM_ERR_OPNOTSUPP,
768 			       N_("next_entry is not supported in the %s "
769 				  " keytab", ""),
770 			       id->prefix);
771 	return HEIM_ERR_OPNOTSUPP;
772     }
773     return (*id->next_entry)(context, id, entry, cursor);
774 }
775 
776 /**
777  * Release all resources associated with `cursor'.
778  *
779  * @param context a Keberos context.
780  * @param id a keytab.
781  * @param cursor the cursor to free.
782  *
783  * @return Return an error code or 0, see krb5_get_error_message().
784  *
785  * @ingroup krb5_keytab
786  */
787 
788 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_end_seq_get(krb5_context context,krb5_keytab id,krb5_kt_cursor * cursor)789 krb5_kt_end_seq_get(krb5_context context,
790 		    krb5_keytab id,
791 		    krb5_kt_cursor *cursor)
792 {
793     if(id->end_seq_get == NULL) {
794 	krb5_set_error_message(context, HEIM_ERR_OPNOTSUPP,
795 			       "end_seq_get is not supported in the %s "
796 			       " keytab", id->prefix);
797 	return HEIM_ERR_OPNOTSUPP;
798     }
799     return (*id->end_seq_get)(context, id, cursor);
800 }
801 
802 /**
803  * Add the entry in `entry' to the keytab `id'.
804  *
805  * @param context a Keberos context.
806  * @param id a keytab.
807  * @param entry the entry to add
808  *
809  * @return Return an error code or 0, see krb5_get_error_message().
810  *
811  * @ingroup krb5_keytab
812  */
813 
814 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_add_entry(krb5_context context,krb5_keytab id,krb5_keytab_entry * entry)815 krb5_kt_add_entry(krb5_context context,
816 		  krb5_keytab id,
817 		  krb5_keytab_entry *entry)
818 {
819     if(id->add == NULL) {
820 	krb5_set_error_message(context, KRB5_KT_NOWRITE,
821 			       N_("Add is not supported in the %s keytab", ""),
822 			       id->prefix);
823 	return KRB5_KT_NOWRITE;
824     }
825     entry->timestamp = time(NULL);
826     return (*id->add)(context, id,entry);
827 }
828 
829 /**
830  * Remove an entry from the keytab, matching is done using
831  * krb5_kt_compare().
832 
833  * @param context a Keberos context.
834  * @param id a keytab.
835  * @param entry the entry to remove
836  *
837  * @return Return an error code or 0, see krb5_get_error_message().
838  *
839  * @ingroup krb5_keytab
840  */
841 
842 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_remove_entry(krb5_context context,krb5_keytab id,krb5_keytab_entry * entry)843 krb5_kt_remove_entry(krb5_context context,
844 		     krb5_keytab id,
845 		     krb5_keytab_entry *entry)
846 {
847     if(id->remove == NULL) {
848 	krb5_set_error_message(context, KRB5_KT_NOWRITE,
849 			       N_("Remove is not supported in the %s keytab", ""),
850 			       id->prefix);
851 	return KRB5_KT_NOWRITE;
852     }
853     return (*id->remove)(context, id, entry);
854 }
855 
856 /**
857  * Return true if the keytab exists and have entries
858  *
859  * @param context a Keberos context.
860  * @param id a keytab.
861  *
862  * @return Return an error code or 0, see krb5_get_error_message().
863  *
864  * @ingroup krb5_keytab
865  */
866 
867 KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL
krb5_kt_have_content(krb5_context context,krb5_keytab id)868 krb5_kt_have_content(krb5_context context,
869 		     krb5_keytab id)
870 {
871     krb5_keytab_entry entry;
872     krb5_kt_cursor cursor;
873     krb5_error_code ret;
874     char *name;
875 
876     memset(&entry, 0, sizeof(entry));
877     ret = krb5_kt_start_seq_get(context, id, &cursor);
878     if (ret)
879 	goto notfound;
880 
881     ret = krb5_kt_next_entry(context, id, &entry, &cursor);
882     krb5_kt_end_seq_get(context, id, &cursor);
883     if (ret)
884 	goto notfound;
885 
886     krb5_kt_free_entry(context, &entry);
887 
888     return 0;
889 
890  notfound:
891     ret = krb5_kt_get_full_name(context, id, &name);
892     if (ret == 0) {
893 	krb5_set_error_message(context, KRB5_KT_NOTFOUND,
894 			       N_("No entry in keytab: %s", ""), name);
895 	free(name);
896     }
897     return KRB5_KT_NOTFOUND;
898 }
899