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      1 /*	$NetBSD: keyset.c,v 1.2 2017/01/28 21:31:48 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2004 - 2007 Kungliga Tekniska Hgskolan
      5  * (Royal Institute of Technology, Stockholm, Sweden).
      6  * All rights reserved.
      7  *
      8  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  *
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  *
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  *
     21  * 3. Neither the name of the Institute nor the names of its contributors
     22  *    may be used to endorse or promote products derived from this software
     23  *    without specific prior written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
     29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     35  * SUCH DAMAGE.
     36  */
     37 
     38 #include "hx_locl.h"
     39 
     40 /**
     41  * @page page_keyset Certificate store operations
     42  *
     43  * Type of certificates store:
     44  * - MEMORY
     45  *   In memory based format. Doesnt support storing.
     46  * - FILE
     47  *   FILE supports raw DER certicates and PEM certicates. When PEM is
     48  *   used the file can contain may certificates and match private
     49  *   keys. Support storing the certificates. DER format only supports
     50  *   on certificate and no private key.
     51  * - PEM-FILE
     52  *   Same as FILE, defaulting to PEM encoded certificates.
     53  * - PEM-FILE
     54  *   Same as FILE, defaulting to DER encoded certificates.
     55  * - PKCS11
     56  * - PKCS12
     57  * - DIR
     58  * - KEYCHAIN
     59  *   Apple Mac OS X KeyChain backed keychain object.
     60  *
     61  * See the library functions here: @ref hx509_keyset
     62  */
     63 
     64 struct hx509_certs_data {
     65     unsigned int ref;
     66     struct hx509_keyset_ops *ops;
     67     void *ops_data;
     68 };
     69 
     70 static struct hx509_keyset_ops *
     71 _hx509_ks_type(hx509_context context, const char *type)
     72 {
     73     int i;
     74 
     75     for (i = 0; i < context->ks_num_ops; i++)
     76 	if (strcasecmp(type, context->ks_ops[i]->name) == 0)
     77 	    return context->ks_ops[i];
     78 
     79     return NULL;
     80 }
     81 
     82 void
     83 _hx509_ks_register(hx509_context context, struct hx509_keyset_ops *ops)
     84 {
     85     struct hx509_keyset_ops **val;
     86 
     87     if (_hx509_ks_type(context, ops->name))
     88 	return;
     89 
     90     val = realloc(context->ks_ops,
     91 		  (context->ks_num_ops + 1) * sizeof(context->ks_ops[0]));
     92     if (val == NULL)
     93 	return;
     94     val[context->ks_num_ops] = ops;
     95     context->ks_ops = val;
     96     context->ks_num_ops++;
     97 }
     98 
     99 /**
    100  * Open or creates a new hx509 certificate store.
    101  *
    102  * @param context A hx509 context
    103  * @param name name of the store, format is TYPE:type-specific-string,
    104  * if NULL is used the MEMORY store is used.
    105  * @param flags list of flags:
    106  * - HX509_CERTS_CREATE create a new keystore of the specific TYPE.
    107  * - HX509_CERTS_UNPROTECT_ALL fails if any private key failed to be extracted.
    108  * @param lock a lock that unlocks the certificates store, use NULL to
    109  * select no password/certifictes/prompt lock (see @ref page_lock).
    110  * @param certs return pointer, free with hx509_certs_free().
    111  *
    112  * @return Returns an hx509 error code.
    113  *
    114  * @ingroup hx509_keyset
    115  */
    116 
    117 int
    118 hx509_certs_init(hx509_context context,
    119 		 const char *name, int flags,
    120 		 hx509_lock lock, hx509_certs *certs)
    121 {
    122     struct hx509_keyset_ops *ops;
    123     const char *residue;
    124     hx509_certs c;
    125     char *type;
    126     int ret;
    127 
    128     *certs = NULL;
    129 
    130     residue = strchr(name, ':');
    131     if (residue) {
    132 	type = malloc(residue - name + 1);
    133 	if (type)
    134 	    strlcpy(type, name, residue - name + 1);
    135 	residue++;
    136 	if (residue[0] == '\0')
    137 	    residue = NULL;
    138     } else {
    139 	type = strdup("MEMORY");
    140 	residue = name;
    141     }
    142     if (type == NULL) {
    143 	hx509_clear_error_string(context);
    144 	return ENOMEM;
    145     }
    146 
    147     ops = _hx509_ks_type(context, type);
    148     if (ops == NULL) {
    149 	hx509_set_error_string(context, 0, ENOENT,
    150 			       "Keyset type %s is not supported", type);
    151 	free(type);
    152 	return ENOENT;
    153     }
    154     free(type);
    155     c = calloc(1, sizeof(*c));
    156     if (c == NULL) {
    157 	hx509_clear_error_string(context);
    158 	return ENOMEM;
    159     }
    160     c->ops = ops;
    161     c->ref = 1;
    162 
    163     ret = (*ops->init)(context, c, &c->ops_data, flags, residue, lock);
    164     if (ret) {
    165 	free(c);
    166 	return ret;
    167     }
    168 
    169     *certs = c;
    170     return 0;
    171 }
    172 
    173 /**
    174  * Write the certificate store to stable storage.
    175  *
    176  * @param context A hx509 context.
    177  * @param certs a certificate store to store.
    178  * @param flags currently unused, use 0.
    179  * @param lock a lock that unlocks the certificates store, use NULL to
    180  * select no password/certifictes/prompt lock (see @ref page_lock).
    181  *
    182  * @return Returns an hx509 error code. HX509_UNSUPPORTED_OPERATION if
    183  * the certificate store doesn't support the store operation.
    184  *
    185  * @ingroup hx509_keyset
    186  */
    187 
    188 int
    189 hx509_certs_store(hx509_context context,
    190 		  hx509_certs certs,
    191 		  int flags,
    192 		  hx509_lock lock)
    193 {
    194     if (certs->ops->store == NULL) {
    195 	hx509_set_error_string(context, 0, HX509_UNSUPPORTED_OPERATION,
    196 			       "keystore if type %s doesn't support "
    197 			       "store operation",
    198 			       certs->ops->name);
    199 	return HX509_UNSUPPORTED_OPERATION;
    200     }
    201 
    202     return (*certs->ops->store)(context, certs, certs->ops_data, flags, lock);
    203 }
    204 
    205 
    206 hx509_certs
    207 hx509_certs_ref(hx509_certs certs)
    208 {
    209     if (certs == NULL)
    210 	return NULL;
    211     if (certs->ref == 0)
    212 	_hx509_abort("certs refcount == 0 on ref");
    213     if (certs->ref == UINT_MAX)
    214 	_hx509_abort("certs refcount == UINT_MAX on ref");
    215     certs->ref++;
    216     return certs;
    217 }
    218 
    219 /**
    220  * Free a certificate store.
    221  *
    222  * @param certs certificate store to free.
    223  *
    224  * @ingroup hx509_keyset
    225  */
    226 
    227 void
    228 hx509_certs_free(hx509_certs *certs)
    229 {
    230     if (*certs) {
    231 	if ((*certs)->ref == 0)
    232 	    _hx509_abort("cert refcount == 0 on free");
    233 	if (--(*certs)->ref > 0)
    234 	    return;
    235 
    236 	(*(*certs)->ops->free)(*certs, (*certs)->ops_data);
    237 	free(*certs);
    238 	*certs = NULL;
    239     }
    240 }
    241 
    242 /**
    243  * Start the integration
    244  *
    245  * @param context a hx509 context.
    246  * @param certs certificate store to iterate over
    247  * @param cursor cursor that will keep track of progress, free with
    248  * hx509_certs_end_seq().
    249  *
    250  * @return Returns an hx509 error code. HX509_UNSUPPORTED_OPERATION is
    251  * returned if the certificate store doesn't support the iteration
    252  * operation.
    253  *
    254  * @ingroup hx509_keyset
    255  */
    256 
    257 int
    258 hx509_certs_start_seq(hx509_context context,
    259 		      hx509_certs certs,
    260 		      hx509_cursor *cursor)
    261 {
    262     int ret;
    263 
    264     if (certs->ops->iter_start == NULL) {
    265 	hx509_set_error_string(context, 0, HX509_UNSUPPORTED_OPERATION,
    266 			       "Keyset type %s doesn't support iteration",
    267 			       certs->ops->name);
    268 	return HX509_UNSUPPORTED_OPERATION;
    269     }
    270 
    271     ret = (*certs->ops->iter_start)(context, certs, certs->ops_data, cursor);
    272     if (ret)
    273 	return ret;
    274 
    275     return 0;
    276 }
    277 
    278 /**
    279  * Get next ceritificate from the certificate keystore pointed out by
    280  * cursor.
    281  *
    282  * @param context a hx509 context.
    283  * @param certs certificate store to iterate over.
    284  * @param cursor cursor that keeps track of progress.
    285  * @param cert return certificate next in store, NULL if the store
    286  * contains no more certificates. Free with hx509_cert_free().
    287  *
    288  * @return Returns an hx509 error code.
    289  *
    290  * @ingroup hx509_keyset
    291  */
    292 
    293 int
    294 hx509_certs_next_cert(hx509_context context,
    295 		      hx509_certs certs,
    296 		      hx509_cursor cursor,
    297 		      hx509_cert *cert)
    298 {
    299     *cert = NULL;
    300     return (*certs->ops->iter)(context, certs, certs->ops_data, cursor, cert);
    301 }
    302 
    303 /**
    304  * End the iteration over certificates.
    305  *
    306  * @param context a hx509 context.
    307  * @param certs certificate store to iterate over.
    308  * @param cursor cursor that will keep track of progress, freed.
    309  *
    310  * @return Returns an hx509 error code.
    311  *
    312  * @ingroup hx509_keyset
    313  */
    314 
    315 int
    316 hx509_certs_end_seq(hx509_context context,
    317 		    hx509_certs certs,
    318 		    hx509_cursor cursor)
    319 {
    320     (*certs->ops->iter_end)(context, certs, certs->ops_data, cursor);
    321     return 0;
    322 }
    323 
    324 /**
    325  * Iterate over all certificates in a keystore and call a function
    326  * for each of them.
    327  *
    328  * @param context a hx509 context.
    329  * @param certs certificate store to iterate over.
    330  * @param func function to call for each certificate. The function
    331  * should return non-zero to abort the iteration, that value is passed
    332  * back to the caller of hx509_certs_iter_f().
    333  * @param ctx context variable that will passed to the function.
    334  *
    335  * @return Returns an hx509 error code.
    336  *
    337  * @ingroup hx509_keyset
    338  */
    339 
    340 int
    341 hx509_certs_iter_f(hx509_context context,
    342 		   hx509_certs certs,
    343 		   int (*func)(hx509_context, void *, hx509_cert),
    344 		   void *ctx)
    345 {
    346     hx509_cursor cursor;
    347     hx509_cert c;
    348     int ret;
    349 
    350     ret = hx509_certs_start_seq(context, certs, &cursor);
    351     if (ret)
    352 	return ret;
    353 
    354     while (1) {
    355 	ret = hx509_certs_next_cert(context, certs, cursor, &c);
    356 	if (ret)
    357 	    break;
    358 	if (c == NULL) {
    359 	    ret = 0;
    360 	    break;
    361 	}
    362 	ret = (*func)(context, ctx, c);
    363 	hx509_cert_free(c);
    364 	if (ret)
    365 	    break;
    366     }
    367 
    368     hx509_certs_end_seq(context, certs, cursor);
    369 
    370     return ret;
    371 }
    372 
    373 #ifdef __BLOCKS__
    374 
    375 static int
    376 certs_iter(hx509_context context, void *ctx, hx509_cert cert)
    377 {
    378     int (^func)(hx509_cert) = ctx;
    379     return func(cert);
    380 }
    381 
    382 /**
    383  * Iterate over all certificates in a keystore and call a block
    384  * for each of them.
    385  *
    386  * @param context a hx509 context.
    387  * @param certs certificate store to iterate over.
    388  * @param func block to call for each certificate. The function
    389  * should return non-zero to abort the iteration, that value is passed
    390  * back to the caller of hx509_certs_iter().
    391  *
    392  * @return Returns an hx509 error code.
    393  *
    394  * @ingroup hx509_keyset
    395  */
    396 
    397 int
    398 hx509_certs_iter(hx509_context context,
    399 		 hx509_certs certs,
    400 		 int (^func)(hx509_cert))
    401 {
    402     return hx509_certs_iter_f(context, certs, certs_iter, func);
    403 }
    404 #endif
    405 
    406 
    407 /**
    408  * Function to use to hx509_certs_iter_f() as a function argument, the
    409  * ctx variable to hx509_certs_iter_f() should be a FILE file descriptor.
    410  *
    411  * @param context a hx509 context.
    412  * @param ctx used by hx509_certs_iter_f().
    413  * @param c a certificate
    414  *
    415  * @return Returns an hx509 error code.
    416  *
    417  * @ingroup hx509_keyset
    418  */
    419 
    420 int
    421 hx509_ci_print_names(hx509_context context, void *ctx, hx509_cert c)
    422 {
    423     Certificate *cert;
    424     hx509_name n;
    425     char *s, *i;
    426 
    427     cert = _hx509_get_cert(c);
    428 
    429     _hx509_name_from_Name(&cert->tbsCertificate.subject, &n);
    430     hx509_name_to_string(n, &s);
    431     hx509_name_free(&n);
    432     _hx509_name_from_Name(&cert->tbsCertificate.issuer, &n);
    433     hx509_name_to_string(n, &i);
    434     hx509_name_free(&n);
    435     fprintf(ctx, "subject: %s\nissuer: %s\n", s, i);
    436     free(s);
    437     free(i);
    438     return 0;
    439 }
    440 
    441 /**
    442  * Add a certificate to the certificiate store.
    443  *
    444  * The receiving keyset certs will either increase reference counter
    445  * of the cert or make a deep copy, either way, the caller needs to
    446  * free the cert itself.
    447  *
    448  * @param context a hx509 context.
    449  * @param certs certificate store to add the certificate to.
    450  * @param cert certificate to add.
    451  *
    452  * @return Returns an hx509 error code.
    453  *
    454  * @ingroup hx509_keyset
    455  */
    456 
    457 int
    458 hx509_certs_add(hx509_context context, hx509_certs certs, hx509_cert cert)
    459 {
    460     if (certs->ops->add == NULL) {
    461 	hx509_set_error_string(context, 0, ENOENT,
    462 			       "Keyset type %s doesn't support add operation",
    463 			       certs->ops->name);
    464 	return ENOENT;
    465     }
    466 
    467     return (*certs->ops->add)(context, certs, certs->ops_data, cert);
    468 }
    469 
    470 /**
    471  * Find a certificate matching the query.
    472  *
    473  * @param context a hx509 context.
    474  * @param certs certificate store to search.
    475  * @param q query allocated with @ref hx509_query functions.
    476  * @param r return certificate (or NULL on error), should be freed
    477  * with hx509_cert_free().
    478  *
    479  * @return Returns an hx509 error code.
    480  *
    481  * @ingroup hx509_keyset
    482  */
    483 
    484 int
    485 hx509_certs_find(hx509_context context,
    486 		 hx509_certs certs,
    487 		 const hx509_query *q,
    488 		 hx509_cert *r)
    489 {
    490     hx509_cursor cursor;
    491     hx509_cert c;
    492     int ret;
    493 
    494     *r = NULL;
    495 
    496     _hx509_query_statistic(context, 0, q);
    497 
    498     if (certs->ops->query)
    499 	return (*certs->ops->query)(context, certs, certs->ops_data, q, r);
    500 
    501     ret = hx509_certs_start_seq(context, certs, &cursor);
    502     if (ret)
    503 	return ret;
    504 
    505     c = NULL;
    506     while (1) {
    507 	ret = hx509_certs_next_cert(context, certs, cursor, &c);
    508 	if (ret)
    509 	    break;
    510 	if (c == NULL)
    511 	    break;
    512 	if (_hx509_query_match_cert(context, q, c)) {
    513 	    *r = c;
    514 	    break;
    515 	}
    516 	hx509_cert_free(c);
    517     }
    518 
    519     hx509_certs_end_seq(context, certs, cursor);
    520     if (ret)
    521 	return ret;
    522     /**
    523      * Return HX509_CERT_NOT_FOUND if no certificate in certs matched
    524      * the query.
    525      */
    526     if (c == NULL) {
    527 	hx509_clear_error_string(context);
    528 	return HX509_CERT_NOT_FOUND;
    529     }
    530 
    531     return 0;
    532 }
    533 
    534 /**
    535  * Filter certificate matching the query.
    536  *
    537  * @param context a hx509 context.
    538  * @param certs certificate store to search.
    539  * @param q query allocated with @ref hx509_query functions.
    540  * @param result the filtered certificate store, caller must free with
    541  *        hx509_certs_free().
    542  *
    543  * @return Returns an hx509 error code.
    544  *
    545  * @ingroup hx509_keyset
    546  */
    547 
    548 int
    549 hx509_certs_filter(hx509_context context,
    550 		   hx509_certs certs,
    551 		   const hx509_query *q,
    552 		   hx509_certs *result)
    553 {
    554     hx509_cursor cursor;
    555     hx509_cert c;
    556     int ret, found = 0;
    557 
    558     _hx509_query_statistic(context, 0, q);
    559 
    560     ret = hx509_certs_init(context, "MEMORY:filter-certs", 0,
    561 			   NULL, result);
    562     if (ret)
    563 	return ret;
    564 
    565     ret = hx509_certs_start_seq(context, certs, &cursor);
    566     if (ret) {
    567 	hx509_certs_free(result);
    568 	return ret;
    569     }
    570 
    571     c = NULL;
    572     while (1) {
    573 	ret = hx509_certs_next_cert(context, certs, cursor, &c);
    574 	if (ret)
    575 	    break;
    576 	if (c == NULL)
    577 	    break;
    578 	if (_hx509_query_match_cert(context, q, c)) {
    579 	    hx509_certs_add(context, *result, c);
    580 	    found = 1;
    581 	}
    582 	hx509_cert_free(c);
    583     }
    584 
    585     hx509_certs_end_seq(context, certs, cursor);
    586     if (ret) {
    587 	hx509_certs_free(result);
    588 	return ret;
    589     }
    590 
    591     /**
    592      * Return HX509_CERT_NOT_FOUND if no certificate in certs matched
    593      * the query.
    594      */
    595     if (!found) {
    596 	hx509_certs_free(result);
    597 	hx509_clear_error_string(context);
    598 	return HX509_CERT_NOT_FOUND;
    599     }
    600 
    601     return 0;
    602 }
    603 
    604 
    605 static int
    606 certs_merge_func(hx509_context context, void *ctx, hx509_cert c)
    607 {
    608     return hx509_certs_add(context, (hx509_certs)ctx, c);
    609 }
    610 
    611 /**
    612  * Merge a certificate store into another. The from store is keep
    613  * intact.
    614  *
    615  * @param context a hx509 context.
    616  * @param to the store to merge into.
    617  * @param from the store to copy the object from.
    618  *
    619  * @return Returns an hx509 error code.
    620  *
    621  * @ingroup hx509_keyset
    622  */
    623 
    624 int
    625 hx509_certs_merge(hx509_context context, hx509_certs to, hx509_certs from)
    626 {
    627     if (from == NULL)
    628 	return 0;
    629     return hx509_certs_iter_f(context, from, certs_merge_func, to);
    630 }
    631 
    632 /**
    633  * Same a hx509_certs_merge() but use a lock and name to describe the
    634  * from source.
    635  *
    636  * @param context a hx509 context.
    637  * @param to the store to merge into.
    638  * @param lock a lock that unlocks the certificates store, use NULL to
    639  * select no password/certifictes/prompt lock (see @ref page_lock).
    640  * @param name name of the source store
    641  *
    642  * @return Returns an hx509 error code.
    643  *
    644  * @ingroup hx509_keyset
    645  */
    646 
    647 int
    648 hx509_certs_append(hx509_context context,
    649 		   hx509_certs to,
    650 		   hx509_lock lock,
    651 		   const char *name)
    652 {
    653     hx509_certs s;
    654     int ret;
    655 
    656     ret = hx509_certs_init(context, name, 0, lock, &s);
    657     if (ret)
    658 	return ret;
    659     ret = hx509_certs_merge(context, to, s);
    660     hx509_certs_free(&s);
    661     return ret;
    662 }
    663 
    664 /**
    665  * Get one random certificate from the certificate store.
    666  *
    667  * @param context a hx509 context.
    668  * @param certs a certificate store to get the certificate from.
    669  * @param c return certificate, should be freed with hx509_cert_free().
    670  *
    671  * @return Returns an hx509 error code.
    672  *
    673  * @ingroup hx509_keyset
    674  */
    675 
    676 int
    677 hx509_get_one_cert(hx509_context context, hx509_certs certs, hx509_cert *c)
    678 {
    679     hx509_cursor cursor;
    680     int ret;
    681 
    682     *c = NULL;
    683 
    684     ret = hx509_certs_start_seq(context, certs, &cursor);
    685     if (ret)
    686 	return ret;
    687 
    688     ret = hx509_certs_next_cert(context, certs, cursor, c);
    689     if (ret)
    690 	return ret;
    691 
    692     hx509_certs_end_seq(context, certs, cursor);
    693     return 0;
    694 }
    695 
    696 static int
    697 certs_info_stdio(void *ctx, const char *str)
    698 {
    699     FILE *f = ctx;
    700     fprintf(f, "%s\n", str);
    701     return 0;
    702 }
    703 
    704 /**
    705  * Print some info about the certificate store.
    706  *
    707  * @param context a hx509 context.
    708  * @param certs certificate store to print information about.
    709  * @param func function that will get each line of the information, if
    710  * NULL is used the data is printed on a FILE descriptor that should
    711  * be passed in ctx, if ctx also is NULL, stdout is used.
    712  * @param ctx parameter to func.
    713  *
    714  * @return Returns an hx509 error code.
    715  *
    716  * @ingroup hx509_keyset
    717  */
    718 
    719 int
    720 hx509_certs_info(hx509_context context,
    721 		 hx509_certs certs,
    722 		 int (*func)(void *, const char *),
    723 		 void *ctx)
    724 {
    725     if (func == NULL) {
    726 	func = certs_info_stdio;
    727 	if (ctx == NULL)
    728 	    ctx = stdout;
    729     }
    730     if (certs->ops->printinfo == NULL) {
    731 	(*func)(ctx, "No info function for certs");
    732 	return 0;
    733     }
    734     return (*certs->ops->printinfo)(context, certs, certs->ops_data,
    735 				    func, ctx);
    736 }
    737 
    738 void
    739 _hx509_pi_printf(int (*func)(void *, const char *), void *ctx,
    740 		 const char *fmt, ...)
    741 {
    742     va_list ap;
    743     char *str;
    744     int ret;
    745 
    746     va_start(ap, fmt);
    747     ret = vasprintf(&str, fmt, ap);
    748     va_end(ap);
    749     if (ret == -1 || str == NULL)
    750 	return;
    751     (*func)(ctx, str);
    752     free(str);
    753 }
    754 
    755 int
    756 _hx509_certs_keys_get(hx509_context context,
    757 		      hx509_certs certs,
    758 		      hx509_private_key **keys)
    759 {
    760     if (certs->ops->getkeys == NULL) {
    761 	*keys = NULL;
    762 	return 0;
    763     }
    764     return (*certs->ops->getkeys)(context, certs, certs->ops_data, keys);
    765 }
    766 
    767 int
    768 _hx509_certs_keys_add(hx509_context context,
    769 		      hx509_certs certs,
    770 		      hx509_private_key key)
    771 {
    772     if (certs->ops->addkey == NULL) {
    773 	hx509_set_error_string(context, 0, EINVAL,
    774 			       "keystore if type %s doesn't support "
    775 			       "key add operation",
    776 			       certs->ops->name);
    777 	return EINVAL;
    778     }
    779     return (*certs->ops->addkey)(context, certs, certs->ops_data, key);
    780 }
    781 
    782 
    783 void
    784 _hx509_certs_keys_free(hx509_context context,
    785 		       hx509_private_key *keys)
    786 {
    787     int i;
    788     for (i = 0; keys[i]; i++)
    789 	hx509_private_key_free(&keys[i]);
    790     free(keys);
    791 }
    792