xref: /netbsd-src/crypto/external/bsd/heimdal/dist/lib/krb5/keytab.c (revision afab4e300d3a9fb07dd8c80daf53d0feb3345706)
1 /*	$NetBSD: keytab.c,v 1.3 2023/06/19 21:41:44 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
5  * (Royal Institute of Technology, Stockholm, Sweden).
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * 3. Neither the name of the Institute nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "krb5_locl.h"
37 
38 /**
39  * @page krb5_keytab_intro The keytab handing functions
40  * @section section_krb5_keytab Kerberos Keytabs
41  *
42  * See the library functions here: @ref krb5_keytab
43  *
44  * Keytabs are long term key storage for servers, their equvalment of
45  * password files.
46  *
47  * Normally the only function that useful for server are to specify
48  * what keytab to use to other core functions like krb5_rd_req()
49  * krb5_kt_resolve(), and krb5_kt_close().
50  *
51  * @subsection krb5_keytab_names Keytab names
52  *
53  * A keytab name is on the form type:residual. The residual part is
54  * specific to each keytab-type.
55  *
56  * When a keytab-name is resolved, the type is matched with an internal
57  * list of keytab types. If there is no matching keytab type,
58  * the default keytab is used. The current default type is FILE.
59  *
60  * The default value can be changed in the configuration file
61  * /etc/krb5.conf by setting the variable
62  * [defaults]default_keytab_name.
63  *
64  * The keytab types that are implemented in Heimdal are:
65  * - file
66  *   store the keytab in a file, the type's name is FILE .  The
67  *   residual part is a filename. For compatibility with other
68  *   Kerberos implemtation WRFILE and JAVA14 is also accepted.  WRFILE
69  *   has the same format as FILE. JAVA14 have a format that is
70  *   compatible with older versions of MIT kerberos and SUN's Java
71  *   based installation.  They store a truncted kvno, so when the knvo
72  *   excess 255, they are truncted in this format.
73  *
74  * - keytab
75  *   store the keytab in a AFS keyfile (usually /usr/afs/etc/KeyFile ),
76  *   the type's name is AFSKEYFILE. The residual part is a filename.
77  *
78  * - memory
79  *   The keytab is stored in a memory segment. This allows sensitive
80  *   and/or temporary data not to be stored on disk. The type's name
81  *   is MEMORY. Each MEMORY keytab is referenced counted by and
82  *   opened by the residual name, so two handles can point to the
83  *   same memory area.  When the last user closes using krb5_kt_close()
84  *   the keytab, the keys in they keytab is memset() to zero and freed
85  *   and can no longer be looked up by name.
86  *
87  *
88  * @subsection krb5_keytab_example Keytab example
89  *
90  *  This is a minimalistic version of ktutil.
91  *
92  * @code
93 int
94 main (int argc, char **argv)
95 {
96     krb5_context context;
97     krb5_keytab keytab;
98     krb5_kt_cursor cursor;
99     krb5_keytab_entry entry;
100     krb5_error_code ret;
101     char *principal;
102 
103     if (krb5_init_context (&context) != 0)
104 	errx(1, "krb5_context");
105 
106     ret = krb5_kt_default (context, &keytab);
107     if (ret)
108 	krb5_err(context, 1, ret, "krb5_kt_default");
109 
110     ret = krb5_kt_start_seq_get(context, keytab, &cursor);
111     if (ret)
112 	krb5_err(context, 1, ret, "krb5_kt_start_seq_get");
113     while((ret = krb5_kt_next_entry(context, keytab, &entry, &cursor)) == 0){
114 	krb5_unparse_name(context, entry.principal, &principal);
115 	printf("principal: %s\n", principal);
116 	free(principal);
117 	krb5_kt_free_entry(context, &entry);
118     }
119     ret = krb5_kt_end_seq_get(context, keytab, &cursor);
120     if (ret)
121 	krb5_err(context, 1, ret, "krb5_kt_end_seq_get");
122     ret = krb5_kt_close(context, keytab);
123     if (ret)
124 	krb5_err(context, 1, ret, "krb5_kt_close");
125     krb5_free_context(context);
126     return 0;
127 }
128  * @endcode
129  *
130  */
131 
132 
133 /**
134  * Register a new keytab backend.
135  *
136  * @param context a Keberos context.
137  * @param ops a backend to register.
138  *
139  * @return Return an error code or 0, see krb5_get_error_message().
140  *
141  * @ingroup krb5_keytab
142  */
143 
144 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_register(krb5_context context,const krb5_kt_ops * ops)145 krb5_kt_register(krb5_context context,
146 		 const krb5_kt_ops *ops)
147 {
148     struct krb5_keytab_data *tmp;
149 
150     if (strlen(ops->prefix) > KRB5_KT_PREFIX_MAX_LEN - 1) {
151 	krb5_set_error_message(context, KRB5_KT_BADNAME,
152 			       N_("can't register cache type, prefix too long", ""));
153 	return KRB5_KT_BADNAME;
154     }
155 
156     tmp = realloc(context->kt_types,
157 		  (context->num_kt_types + 1) * sizeof(*context->kt_types));
158     if(tmp == NULL)
159 	return krb5_enomem(context);
160     memcpy(&tmp[context->num_kt_types], ops,
161 	   sizeof(tmp[context->num_kt_types]));
162     context->kt_types = tmp;
163     context->num_kt_types++;
164     return 0;
165 }
166 
167 static const char *
keytab_name(const char * name,const char ** type,size_t * type_len)168 keytab_name(const char *name, const char **type, size_t *type_len)
169 {
170     const char *residual;
171 
172     residual = strchr(name, ':');
173 
174     if (residual == NULL ||
175 	ISPATHSEP(name[0])
176 #ifdef _WIN32
177         /* Avoid treating <drive>:<path> as a keytab type
178          * specification */
179         || name + 1 == residual
180 #endif
181         ) {
182 
183         *type = "FILE";
184         *type_len = strlen(*type);
185         residual = name;
186     } else {
187         *type = name;
188         *type_len = residual - name;
189         residual++;
190     }
191 
192     return residual;
193 }
194 
195 /**
196  * Resolve the keytab name (of the form `type:residual') in `name'
197  * into a keytab in `id'.
198  *
199  * @param context a Keberos context.
200  * @param name name to resolve
201  * @param id resulting keytab, free with krb5_kt_close().
202  *
203  * @return Return an error code or 0, see krb5_get_error_message().
204  *
205  * @ingroup krb5_keytab
206  */
207 
208 
209 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_resolve(krb5_context context,const char * name,krb5_keytab * id)210 krb5_kt_resolve(krb5_context context,
211 		const char *name,
212 		krb5_keytab *id)
213 {
214     krb5_keytab k;
215     int i;
216     const char *type, *residual;
217     size_t type_len;
218     krb5_error_code ret;
219 
220     residual = keytab_name(name, &type, &type_len);
221 
222     for(i = 0; i < context->num_kt_types; i++) {
223 	if(strncasecmp(type, context->kt_types[i].prefix, type_len) == 0)
224 	    break;
225     }
226     if(i == context->num_kt_types) {
227 	krb5_set_error_message(context, KRB5_KT_UNKNOWN_TYPE,
228 			       N_("unknown keytab type %.*s", "type"),
229 			       (int)type_len, type);
230 	return KRB5_KT_UNKNOWN_TYPE;
231     }
232 
233     k = malloc (sizeof(*k));
234     if (k == NULL)
235 	return krb5_enomem(context);
236     memcpy(k, &context->kt_types[i], sizeof(*k));
237     k->data = NULL;
238     ret = (*k->resolve)(context, residual, k);
239     if(ret) {
240 	free(k);
241 	k = NULL;
242     }
243     *id = k;
244     return ret;
245 }
246 
247 /*
248  * Default ktname from context with possible environment
249  * override
250  */
default_ktname(krb5_context context)251 static const char *default_ktname(krb5_context context)
252 {
253     const char *tmp = NULL;
254 
255     if(!issuid())
256 	tmp = getenv("KRB5_KTNAME");
257     if(tmp != NULL)
258 	return tmp;
259     return context->default_keytab;
260 }
261 
262 /**
263  * copy the name of the default keytab into `name'.
264  *
265  * @param context a Keberos context.
266  * @param name buffer where the name will be written
267  * @param namesize length of name
268  *
269  * @return Return an error code or 0, see krb5_get_error_message().
270  *
271  * @ingroup krb5_keytab
272  */
273 
274 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_default_name(krb5_context context,char * name,size_t namesize)275 krb5_kt_default_name(krb5_context context, char *name, size_t namesize)
276 {
277     if (strlcpy (name, default_ktname(context), namesize) >= namesize) {
278 	krb5_clear_error_message (context);
279 	return KRB5_CONFIG_NOTENUFSPACE;
280     }
281     return 0;
282 }
283 
284 /**
285  * Copy the name of the default modify keytab into `name'.
286  *
287  * @param context a Keberos context.
288  * @param name buffer where the name will be written
289  * @param namesize length of name
290  *
291  * @return Return an error code or 0, see krb5_get_error_message().
292  *
293  * @ingroup krb5_keytab
294  */
295 
296 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_default_modify_name(krb5_context context,char * name,size_t namesize)297 krb5_kt_default_modify_name(krb5_context context, char *name, size_t namesize)
298 {
299     const char *kt;
300 
301     if(context->default_keytab_modify == NULL) {
302 	kt = default_ktname(context);
303 
304 	if (strncasecmp(kt, "ANY:", 4) == 0) {
305 	    size_t len = strcspn(kt + 4, ",");
306 	    if (len >= namesize) {
307 		krb5_clear_error_message(context);
308 		return KRB5_CONFIG_NOTENUFSPACE;
309 	    }
310 	    strlcpy(name, kt + 4, namesize);
311 	    name[len] = '\0';
312 	    return 0;
313 	}
314     } else
315 	kt = context->default_keytab_modify;
316     if (strlcpy (name, kt, namesize) >= namesize) {
317 	krb5_clear_error_message (context);
318 	return KRB5_CONFIG_NOTENUFSPACE;
319     }
320     return 0;
321 }
322 
323 /**
324  * Set `id' to the default keytab.
325  *
326  * @param context a Keberos context.
327  * @param id the new default keytab.
328  *
329  * @return Return an error code or 0, see krb5_get_error_message().
330  *
331  * @ingroup krb5_keytab
332  */
333 
334 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_default(krb5_context context,krb5_keytab * id)335 krb5_kt_default(krb5_context context, krb5_keytab *id)
336 {
337     return krb5_kt_resolve (context, default_ktname(context), id);
338 }
339 
340 /**
341  * Read the key identified by `(principal, vno, enctype)' from the
342  * keytab in `keyprocarg' (the default if == NULL) into `*key'.
343  *
344  * @param context a Keberos context.
345  * @param keyprocarg
346  * @param principal
347  * @param vno
348  * @param enctype
349  * @param key
350  *
351  * @return Return an error code or 0, see krb5_get_error_message().
352  *
353  * @ingroup krb5_keytab
354  */
355 
356 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)357 krb5_kt_read_service_key(krb5_context context,
358 			 krb5_pointer keyprocarg,
359 			 krb5_principal principal,
360 			 krb5_kvno vno,
361 			 krb5_enctype enctype,
362 			 krb5_keyblock **key)
363 {
364     krb5_keytab keytab = NULL; /* Quiet lint */
365     krb5_keytab_entry entry;
366     krb5_error_code ret;
367 
368     memset(&entry, 0, sizeof(entry));
369     if (keyprocarg)
370 	ret = krb5_kt_resolve (context, keyprocarg, &keytab);
371     else
372 	ret = krb5_kt_default (context, &keytab);
373 
374     if (ret)
375 	return ret;
376 
377     ret = krb5_kt_get_entry (context, keytab, principal, vno, enctype, &entry);
378     if (ret == 0) {
379         ret = krb5_copy_keyblock (context, &entry.keyblock, key);
380         krb5_kt_free_entry(context, &entry);
381     }
382     krb5_kt_close (context, keytab);
383     return ret;
384 }
385 
386 /**
387  * Return the type of the `keytab' in the string `prefix of length
388  * `prefixsize'.
389  *
390  * @param context a Keberos context.
391  * @param keytab the keytab to get the prefix for
392  * @param prefix prefix buffer
393  * @param prefixsize length of prefix buffer
394  *
395  * @return Return an error code or 0, see krb5_get_error_message().
396  *
397  * @ingroup krb5_keytab
398  */
399 
400 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_get_type(krb5_context context,krb5_keytab keytab,char * prefix,size_t prefixsize)401 krb5_kt_get_type(krb5_context context,
402 		 krb5_keytab keytab,
403 		 char *prefix,
404 		 size_t prefixsize)
405 {
406     strlcpy(prefix, keytab->prefix, prefixsize);
407     return 0;
408 }
409 
410 /**
411  * Retrieve the name of the keytab `keytab' into `name', `namesize'
412  *
413  * @param context a Keberos context.
414  * @param keytab the keytab to get the name for.
415  * @param name name buffer.
416  * @param namesize size of name buffer.
417  *
418  * @return Return an error code or 0, see krb5_get_error_message().
419  *
420  * @ingroup krb5_keytab
421  */
422 
423 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_get_name(krb5_context context,krb5_keytab keytab,char * name,size_t namesize)424 krb5_kt_get_name(krb5_context context,
425 		 krb5_keytab keytab,
426 		 char *name,
427 		 size_t namesize)
428 {
429     return (*keytab->get_name)(context, keytab, name, namesize);
430 }
431 
432 /**
433  * Retrieve the full name of the keytab `keytab' and store the name in
434  * `str'.
435  *
436  * @param context a Keberos context.
437  * @param keytab keytab to get name for.
438  * @param str the name of the keytab name, usee krb5_xfree() to free
439  *        the string.  On error, *str is set to NULL.
440  *
441  * @return Return an error code or 0, see krb5_get_error_message().
442  *
443  * @ingroup krb5_keytab
444  */
445 
446 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_get_full_name(krb5_context context,krb5_keytab keytab,char ** str)447 krb5_kt_get_full_name(krb5_context context,
448 		      krb5_keytab keytab,
449 		      char **str)
450 {
451     char type[KRB5_KT_PREFIX_MAX_LEN];
452     char name[MAXPATHLEN];
453     krb5_error_code ret;
454 
455     *str = NULL;
456 
457     ret = krb5_kt_get_type(context, keytab, type, sizeof(type));
458     if (ret)
459 	return ret;
460 
461     ret = krb5_kt_get_name(context, keytab, name, sizeof(name));
462     if (ret)
463 	return ret;
464 
465     if (asprintf(str, "%s:%s", type, name) == -1) {
466 	*str = NULL;
467 	return krb5_enomem(context);
468     }
469 
470     return 0;
471 }
472 
473 /**
474  * Finish using the keytab in `id'.  All resources will be released,
475  * even on errors.
476  *
477  * @param context a Keberos context.
478  * @param id keytab to close.
479  *
480  * @return Return an error code or 0, see krb5_get_error_message().
481  *
482  * @ingroup krb5_keytab
483  */
484 
485 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_close(krb5_context context,krb5_keytab id)486 krb5_kt_close(krb5_context context,
487 	      krb5_keytab id)
488 {
489     krb5_error_code ret = 0;
490 
491     if (id) {
492         ret = (id->close)(context, id);
493         memset(id, 0, sizeof(*id));
494         free(id);
495     }
496     return ret;
497 }
498 
499 /**
500  * Destroy (remove) the keytab in `id'.  All resources will be released,
501  * even on errors, does the equvalment of krb5_kt_close() on the resources.
502  *
503  * @param context a Keberos context.
504  * @param id keytab to destroy.
505  *
506  * @return Return an error code or 0, see krb5_get_error_message().
507  *
508  * @ingroup krb5_keytab
509  */
510 
511 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_destroy(krb5_context context,krb5_keytab id)512 krb5_kt_destroy(krb5_context context,
513 		krb5_keytab id)
514 {
515     krb5_error_code ret;
516 
517     ret = (*id->destroy)(context, id);
518     krb5_kt_close(context, id);
519     return ret;
520 }
521 
522 /*
523  * Match any aliases in keytab `entry' with `principal'.
524  */
525 
526 static krb5_boolean
compare_aliases(krb5_context context,krb5_keytab_entry * entry,krb5_const_principal principal)527 compare_aliases(krb5_context context,
528 		 krb5_keytab_entry *entry,
529 		 krb5_const_principal principal)
530 {
531     unsigned int i;
532     if (entry->aliases == NULL)
533 	return FALSE;
534     for (i = 0; i < entry->aliases->len; i++)
535 	if (krb5_principal_compare(context, &entry->aliases->val[i], principal))
536 	    return TRUE;
537     return FALSE;
538 }
539 
540 /**
541  * Compare `entry' against `principal, vno, enctype'.
542  * Any of `principal, vno, enctype' might be 0 which acts as a wildcard.
543  * Return TRUE if they compare the same, FALSE otherwise.
544  *
545  * @param context a Keberos context.
546  * @param entry an entry to match with.
547  * @param principal principal to match, NULL matches all principals.
548  * @param vno key version to match, 0 matches all key version numbers.
549  * @param enctype encryption type to match, 0 matches all encryption types.
550  *
551  * @return Return TRUE or match, FALSE if not matched.
552  *
553  * @ingroup krb5_keytab
554  */
555 
556 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)557 krb5_kt_compare(krb5_context context,
558 		krb5_keytab_entry *entry,
559 		krb5_const_principal principal,
560 		krb5_kvno vno,
561 		krb5_enctype enctype)
562 {
563     /* krb5_principal_compare() does not special-case the referral realm */
564     if (principal != NULL && strcmp(principal->realm, "") == 0 &&
565         !(krb5_principal_compare_any_realm(context, entry->principal, principal) ||
566           compare_aliases(context, entry, principal))) {
567         return FALSE;
568     } else if (principal != NULL && strcmp(principal->realm, "") != 0 &&
569         !(krb5_principal_compare(context, entry->principal, principal) ||
570           compare_aliases(context, entry, principal))) {
571 	return FALSE;
572     }
573     if (vno && vno != entry->vno)
574 	return FALSE;
575     if (enctype && enctype != entry->keyblock.keytype)
576 	return FALSE;
577     return TRUE;
578 }
579 
580 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_kt_principal_not_found(krb5_context context,krb5_error_code ret,krb5_keytab id,krb5_const_principal principal,krb5_enctype enctype,int kvno)581 _krb5_kt_principal_not_found(krb5_context context,
582 			     krb5_error_code ret,
583 			     krb5_keytab id,
584 			     krb5_const_principal principal,
585 			     krb5_enctype enctype,
586 			     int kvno)
587 {
588     char princ[256], kvno_str[25], *kt_name;
589     char *enctype_str = NULL;
590 
591     krb5_unparse_name_fixed (context, principal, princ, sizeof(princ));
592     krb5_kt_get_full_name (context, id, &kt_name);
593     if (enctype)
594 	krb5_enctype_to_string(context, enctype, &enctype_str);
595 
596     if (kvno)
597 	snprintf(kvno_str, sizeof(kvno_str), "(kvno %d)", kvno);
598     else
599 	kvno_str[0] = '\0';
600 
601     krb5_set_error_message (context, ret,
602 			    N_("Failed to find %s%s in keytab %s (%s)",
603 			       "principal, kvno, keytab file, enctype"),
604 			    princ,
605 			    kvno_str,
606 			    kt_name ? kt_name : "unknown keytab",
607 			    enctype_str ? enctype_str : "unknown enctype");
608     free(kt_name);
609     if (enctype_str)
610 	free(enctype_str);
611     return ret;
612 }
613 
614 static krb5_error_code
krb5_kt_get_entry_wrapped(krb5_context context,krb5_keytab id,krb5_const_principal principal,krb5_kvno kvno,krb5_enctype enctype,krb5_keytab_entry * entry)615 krb5_kt_get_entry_wrapped(krb5_context context,
616 			  krb5_keytab id,
617 			  krb5_const_principal principal,
618 			  krb5_kvno kvno,
619 			  krb5_enctype enctype,
620 			  krb5_keytab_entry *entry)
621 {
622     krb5_keytab_entry tmp;
623     krb5_error_code ret;
624     krb5_kt_cursor cursor;
625 
626     if(id->get)
627 	return (*id->get)(context, id, principal, kvno, enctype, entry);
628 
629     memset(&tmp, 0, sizeof(tmp));
630     ret = krb5_kt_start_seq_get (context, id, &cursor);
631     if (ret) {
632 	/* This is needed for krb5_verify_init_creds, but keep error
633 	 * string from previous error for the human. */
634 	context->error_code = KRB5_KT_NOTFOUND;
635 	return KRB5_KT_NOTFOUND;
636     }
637 
638     entry->vno = 0;
639     while (krb5_kt_next_entry(context, id, &tmp, &cursor) == 0) {
640 	if (krb5_kt_compare(context, &tmp, principal, 0, enctype)) {
641 	    /* the file keytab might only store the lower 8 bits of
642 	       the kvno, so only compare those bits */
643 	    if (kvno == tmp.vno
644 		|| (tmp.vno < 256 && kvno % 256 == tmp.vno)) {
645 		krb5_kt_copy_entry_contents (context, &tmp, entry);
646 		krb5_kt_free_entry (context, &tmp);
647 		krb5_kt_end_seq_get(context, id, &cursor);
648 		return 0;
649 	    } else if (kvno == 0 && tmp.vno > entry->vno) {
650 		if (entry->vno)
651 		    krb5_kt_free_entry (context, entry);
652 		krb5_kt_copy_entry_contents (context, &tmp, entry);
653 	    }
654 	}
655 	krb5_kt_free_entry(context, &tmp);
656     }
657     krb5_kt_end_seq_get (context, id, &cursor);
658     if (entry->vno == 0)
659 	return _krb5_kt_principal_not_found(context, KRB5_KT_NOTFOUND,
660 					    id, principal, enctype, kvno);
661     return 0;
662 }
663 
664 /**
665  * Retrieve the keytab entry for `principal, kvno, enctype' into `entry'
666  * from the keytab `id'. Matching is done like krb5_kt_compare().
667  *
668  * @param context a Keberos context.
669  * @param id a keytab.
670  * @param principal principal to match, NULL matches all principals.
671  * @param kvno key version to match, 0 matches all key version numbers.
672  * @param enctype encryption type to match, 0 matches all encryption types.
673  * @param entry the returned entry, free with krb5_kt_free_entry().
674  *
675  * @return Return an error code or 0, see krb5_get_error_message().
676  *
677  * @ingroup krb5_keytab
678  */
679 
680 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)681 krb5_kt_get_entry(krb5_context context,
682 		  krb5_keytab id,
683 		  krb5_const_principal principal,
684 		  krb5_kvno kvno,
685 		  krb5_enctype enctype,
686 		  krb5_keytab_entry *entry)
687 {
688     krb5_error_code ret;
689     krb5_const_principal try_princ;
690     krb5_name_canon_iterator name_canon_iter;
691 
692     if (!principal)
693 	return krb5_kt_get_entry_wrapped(context, id, principal, kvno, enctype,
694 					 entry);
695 
696     ret = krb5_name_canon_iterator_start(context, principal, &name_canon_iter);
697     if (ret)
698 	return ret;
699 
700     do {
701 	ret = krb5_name_canon_iterate(context, &name_canon_iter, &try_princ,
702                                       NULL);
703 	if (ret)
704 	    break;
705         if (try_princ == NULL) {
706             ret = KRB5_KT_NOTFOUND;
707             continue;
708         }
709 	ret = krb5_kt_get_entry_wrapped(context, id, try_princ, kvno,
710 					enctype, entry);
711     } while (ret == KRB5_KT_NOTFOUND && name_canon_iter);
712 
713     if (ret != KRB5_KT_NOTFOUND)
714 	krb5_set_error_message(context, ret,
715 			       N_("Name canon failed while searching keytab",
716 				  ""));
717     krb5_free_name_canon_iterator(context, name_canon_iter);
718     return ret;
719 }
720 
721 /**
722  * Copy the contents of `in' into `out'.
723  *
724  * @param context a Keberos context.
725  * @param in the keytab entry to copy.
726  * @param out the copy of the keytab entry, free with krb5_kt_free_entry().
727  *
728  * @return Return an error code or 0, see krb5_get_error_message().
729  *
730  * @ingroup krb5_keytab
731  */
732 
733 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)734 krb5_kt_copy_entry_contents(krb5_context context,
735 			    const krb5_keytab_entry *in,
736 			    krb5_keytab_entry *out)
737 {
738     krb5_error_code ret;
739 
740     memset(out, 0, sizeof(*out));
741 
742     ret = krb5_copy_principal (context, in->principal, &out->principal);
743     if (ret)
744 	return ret;
745     ret = krb5_copy_keyblock_contents (context,
746 				       &in->keyblock,
747 				       &out->keyblock);
748     if (ret) {
749         krb5_free_principal(context, out->principal);
750         memset(out, 0, sizeof(*out));
751         return ret;
752     }
753     out->vno = in->vno;
754     out->timestamp = in->timestamp;
755     return 0;
756 }
757 
758 /**
759  * Free the contents of `entry'.
760  *
761  * @param context a Keberos context.
762  * @param entry the entry to free
763  *
764  * @return Return an error code or 0, see krb5_get_error_message().
765  *
766  * @ingroup krb5_keytab
767  */
768 
769 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_free_entry(krb5_context context,krb5_keytab_entry * entry)770 krb5_kt_free_entry(krb5_context context,
771 		   krb5_keytab_entry *entry)
772 {
773     krb5_free_principal (context, entry->principal);
774     krb5_free_keyblock_contents (context, &entry->keyblock);
775     memset(entry, 0, sizeof(*entry));
776     return 0;
777 }
778 
779 /**
780  * Set `cursor' to point at the beginning of `id'.
781  *
782  * @param context a Keberos context.
783  * @param id a keytab.
784  * @param cursor a newly allocated cursor, free with krb5_kt_end_seq_get().
785  *
786  * @return Return an error code or 0, see krb5_get_error_message().
787  *
788  * @ingroup krb5_keytab
789  */
790 
791 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_start_seq_get(krb5_context context,krb5_keytab id,krb5_kt_cursor * cursor)792 krb5_kt_start_seq_get(krb5_context context,
793 		      krb5_keytab id,
794 		      krb5_kt_cursor *cursor)
795 {
796     if(id->start_seq_get == NULL) {
797 	krb5_set_error_message(context, HEIM_ERR_OPNOTSUPP,
798 			       N_("start_seq_get is not supported "
799 				  "in the %s keytab type", ""),
800 			       id->prefix);
801 	return HEIM_ERR_OPNOTSUPP;
802     }
803     return (*id->start_seq_get)(context, id, cursor);
804 }
805 
806 /**
807  * Get the next entry from keytab, advance the cursor.  On last entry
808  * the function will return KRB5_KT_END.
809  *
810  * @param context a Keberos context.
811  * @param id a keytab.
812  * @param entry the returned entry, free with krb5_kt_free_entry().
813  * @param cursor the cursor of the iteration.
814  *
815  * @return Return an error code or 0, see krb5_get_error_message().
816  *
817  * @ingroup krb5_keytab
818  */
819 
820 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)821 krb5_kt_next_entry(krb5_context context,
822 		   krb5_keytab id,
823 		   krb5_keytab_entry *entry,
824 		   krb5_kt_cursor *cursor)
825 {
826     if(id->next_entry == NULL) {
827 	krb5_set_error_message(context, HEIM_ERR_OPNOTSUPP,
828 			       N_("next_entry is not supported in the %s "
829 				  " keytab", ""),
830 			       id->prefix);
831 	return HEIM_ERR_OPNOTSUPP;
832     }
833     return (*id->next_entry)(context, id, entry, cursor);
834 }
835 
836 /**
837  * Release all resources associated with `cursor'.
838  *
839  * @param context a Keberos context.
840  * @param id a keytab.
841  * @param cursor the cursor to free.
842  *
843  * @return Return an error code or 0, see krb5_get_error_message().
844  *
845  * @ingroup krb5_keytab
846  */
847 
848 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_end_seq_get(krb5_context context,krb5_keytab id,krb5_kt_cursor * cursor)849 krb5_kt_end_seq_get(krb5_context context,
850 		    krb5_keytab id,
851 		    krb5_kt_cursor *cursor)
852 {
853     if(id->end_seq_get == NULL) {
854 	krb5_set_error_message(context, HEIM_ERR_OPNOTSUPP,
855 			       "end_seq_get is not supported in the %s "
856 			       " keytab", id->prefix);
857 	return HEIM_ERR_OPNOTSUPP;
858     }
859     return (*id->end_seq_get)(context, id, cursor);
860 }
861 
862 /**
863  * Add the entry in `entry' to the keytab `id'.
864  *
865  * @param context a Keberos context.
866  * @param id a keytab.
867  * @param entry the entry to add
868  *
869  * @return Return an error code or 0, see krb5_get_error_message().
870  *
871  * @ingroup krb5_keytab
872  */
873 
874 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_add_entry(krb5_context context,krb5_keytab id,krb5_keytab_entry * entry)875 krb5_kt_add_entry(krb5_context context,
876 		  krb5_keytab id,
877 		  krb5_keytab_entry *entry)
878 {
879     if(id->add == NULL) {
880 	krb5_set_error_message(context, KRB5_KT_NOWRITE,
881 			       N_("Add is not supported in the %s keytab", ""),
882 			       id->prefix);
883 	return KRB5_KT_NOWRITE;
884     }
885     entry->timestamp = time(NULL);
886     return (*id->add)(context, id,entry);
887 }
888 
889 /**
890  * Remove an entry from the keytab, matching is done using
891  * krb5_kt_compare().
892 
893  * @param context a Keberos context.
894  * @param id a keytab.
895  * @param entry the entry to remove
896  *
897  * @return Return an error code or 0, see krb5_get_error_message().
898  *
899  * @ingroup krb5_keytab
900  */
901 
902 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_remove_entry(krb5_context context,krb5_keytab id,krb5_keytab_entry * entry)903 krb5_kt_remove_entry(krb5_context context,
904 		     krb5_keytab id,
905 		     krb5_keytab_entry *entry)
906 {
907     if(id->remove == NULL) {
908 	krb5_set_error_message(context, KRB5_KT_NOWRITE,
909 			       N_("Remove is not supported in the %s keytab", ""),
910 			       id->prefix);
911 	return KRB5_KT_NOWRITE;
912     }
913     return (*id->remove)(context, id, entry);
914 }
915 
916 /**
917  * Return true if the keytab exists and have entries
918  *
919  * @param context a Keberos context.
920  * @param id a keytab.
921  *
922  * @return Return an error code or 0, see krb5_get_error_message().
923  *
924  * @ingroup krb5_keytab
925  */
926 
927 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kt_have_content(krb5_context context,krb5_keytab id)928 krb5_kt_have_content(krb5_context context,
929 		     krb5_keytab id)
930 {
931     krb5_keytab_entry entry;
932     krb5_kt_cursor cursor;
933     krb5_error_code ret;
934     char *name;
935 
936     memset(&entry, 0, sizeof(entry));
937     ret = krb5_kt_start_seq_get(context, id, &cursor);
938     if (ret)
939 	goto notfound;
940 
941     ret = krb5_kt_next_entry(context, id, &entry, &cursor);
942     krb5_kt_end_seq_get(context, id, &cursor);
943     if (ret)
944 	goto notfound;
945 
946     krb5_kt_free_entry(context, &entry);
947 
948     return 0;
949 
950  notfound:
951     ret = krb5_kt_get_full_name(context, id, &name);
952     if (ret == 0) {
953 	krb5_set_error_message(context, KRB5_KT_NOTFOUND,
954 			       N_("No entry in keytab: %s", ""), name);
955 	free(name);
956     }
957     return KRB5_KT_NOTFOUND;
958 }
959