lib/libcrypto/pkcs7/pk7_doit.c

   1 /* $OpenBSD: pk7_doit.c,v 1.42 2017/05/02 03:59:45 deraadt Exp $ */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include <stdlib.h>
  61 #include <string.h>
  62
  63 #include <openssl/err.h>
  64 #include <openssl/objects.h>
  65 #include <openssl/x509.h>
  66 #include <openssl/x509v3.h>
  67
  68 static int add_attribute(STACK_OF(X509_ATTRIBUTE) **sk, int nid, int atrtype,
  69     void *value);
  70 static ASN1_TYPE *get_attribute(STACK_OF(X509_ATTRIBUTE) *sk, int nid);
  71
  72 static int
  73 PKCS7_type_is_other(PKCS7* p7)
  74 {
  75         int isOther = 1;
  76
  77         int nid = OBJ_obj2nid(p7->type);
  78
  79         switch (nid ) {
  80         case NID_pkcs7_data:
  81         case NID_pkcs7_signed:
  82         case NID_pkcs7_enveloped:
  83         case NID_pkcs7_signedAndEnveloped:
  84         case NID_pkcs7_digest:
  85         case NID_pkcs7_encrypted:
  86                 isOther = 0;
  87                 break;
  88         default:
  89                 isOther = 1;
  90         }
  91
  92         return isOther;
  93
  94 }
  95
  96 static ASN1_OCTET_STRING *
  97 PKCS7_get_octet_string(PKCS7 *p7)
  98 {
  99         if (PKCS7_type_is_data(p7))
 100                 return p7->d.data;
 101         if (PKCS7_type_is_other(p7) && p7->d.other &&
 102             (p7->d.other->type == V_ASN1_OCTET_STRING))
 103                 return p7->d.other->value.octet_string;
 104         return NULL;
 105 }
 106
 107 static int
 108 PKCS7_bio_add_digest(BIO **pbio, X509_ALGOR *alg)
 109 {
 110         BIO *btmp;
 111         const EVP_MD *md;
 112         if ((btmp = BIO_new(BIO_f_md())) == NULL) {
 113                 PKCS7error(ERR_R_BIO_LIB);
 114                 goto err;
 115         }
 116
 117         md = EVP_get_digestbyobj(alg->algorithm);
 118         if (md == NULL) {
 119                 PKCS7error(PKCS7_R_UNKNOWN_DIGEST_TYPE);
 120                 goto err;
 121         }
 122
 123         BIO_set_md(btmp, md);
 124         if (*pbio == NULL)
 125                 *pbio = btmp;
 126         else if (!BIO_push(*pbio, btmp)) {
 127                 PKCS7error(ERR_R_BIO_LIB);
 128                 goto err;
 129         }
 130         btmp = NULL;
 131
 132         return 1;
 133
 134 err:
 135         BIO_free(btmp);
 136         return 0;
 137
 138 }
 139
 140 static int
 141 pkcs7_encode_rinfo(PKCS7_RECIP_INFO *ri, unsigned char *key, int keylen)
 142 {
 143         EVP_PKEY_CTX *pctx = NULL;
 144         EVP_PKEY *pkey = NULL;
 145         unsigned char *ek = NULL;
 146         int ret = 0;
 147         size_t eklen;
 148
 149         pkey = X509_get_pubkey(ri->cert);
 150         if (!pkey)
 151                 return 0;
 152
 153         pctx = EVP_PKEY_CTX_new(pkey, NULL);
 154         if (!pctx)
 155                 return 0;
 156
 157         if (EVP_PKEY_encrypt_init(pctx) <= 0)
 158                 goto err;
 159
 160         if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_ENCRYPT,
 161             EVP_PKEY_CTRL_PKCS7_ENCRYPT, 0, ri) <= 0) {
 162                 PKCS7error(PKCS7_R_CTRL_ERROR);
 163                 goto err;
 164         }
 165
 166         if (EVP_PKEY_encrypt(pctx, NULL, &eklen, key, keylen) <= 0)
 167                 goto err;
 168
 169         ek = malloc(eklen);
 170
 171         if (ek == NULL) {
 172                 PKCS7error(ERR_R_MALLOC_FAILURE);
 173                 goto err;
 174         }
 175
 176         if (EVP_PKEY_encrypt(pctx, ek, &eklen, key, keylen) <= 0)
 177                 goto err;
 178
 179         ASN1_STRING_set0(ri->enc_key, ek, eklen);
 180         ek = NULL;
 181
 182         ret = 1;
 183
 184 err:
 185         EVP_PKEY_free(pkey);
 186         EVP_PKEY_CTX_free(pctx);
 187         free(ek);
 188         return ret;
 189 }
 190
 191
 192 static int
 193 pkcs7_decrypt_rinfo(unsigned char **pek, int *peklen, PKCS7_RECIP_INFO *ri,
 194     EVP_PKEY *pkey)
 195 {
 196         EVP_PKEY_CTX *pctx = NULL;
 197         unsigned char *ek = NULL;
 198         size_t eklen;
 199
 200         int ret = -1;
 201
 202         pctx = EVP_PKEY_CTX_new(pkey, NULL);
 203         if (!pctx)
 204                 return -1;
 205
 206         if (EVP_PKEY_decrypt_init(pctx) <= 0)
 207                 goto err;
 208
 209         if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_DECRYPT,
 210             EVP_PKEY_CTRL_PKCS7_DECRYPT, 0, ri) <= 0) {
 211                 PKCS7error(PKCS7_R_CTRL_ERROR);
 212                 goto err;
 213         }
 214
 215         if (EVP_PKEY_decrypt(pctx, NULL, &eklen,
 216             ri->enc_key->data, ri->enc_key->length) <= 0)
 217                 goto err;
 218
 219         ek = malloc(eklen);
 220         if (ek == NULL) {
 221                 PKCS7error(ERR_R_MALLOC_FAILURE);
 222                 goto err;
 223         }
 224
 225         if (EVP_PKEY_decrypt(pctx, ek, &eklen,
 226             ri->enc_key->data, ri->enc_key->length) <= 0) {
 227                 ret = 0;
 228                 PKCS7error(ERR_R_EVP_LIB);
 229                 goto err;
 230         }
 231
 232         ret = 1;
 233
 234         freezero(*pek, *peklen);
 235
 236         *pek = ek;
 237         *peklen = eklen;
 238
 239 err:
 240         EVP_PKEY_CTX_free(pctx);
 241         if (!ret && ek)
 242                 free(ek);
 243
 244         return ret;
 245 }
 246
 247 BIO *
 248 PKCS7_dataInit(PKCS7 *p7, BIO *bio)
 249 {
 250         int i;
 251         BIO *out = NULL, *btmp = NULL;
 252         X509_ALGOR *xa = NULL;
 253         const EVP_CIPHER *evp_cipher = NULL;
 254         STACK_OF(X509_ALGOR) *md_sk = NULL;
 255         STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
 256         X509_ALGOR *xalg = NULL;
 257         PKCS7_RECIP_INFO *ri = NULL;
 258         ASN1_OCTET_STRING *os = NULL;
 259
 260         if (p7 == NULL) {
 261                 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
 262                 return NULL;
 263         }
 264
 265         /*
 266          * The content field in the PKCS7 ContentInfo is optional,
 267          * but that really only applies to inner content (precisely,
 268          * detached signatures).
 269          *
 270          * When reading content, missing outer content is therefore
 271          * treated as an error.
 272          *
 273          * When creating content, PKCS7_content_new() must be called
 274          * before calling this method, so a NULL p7->d is always
 275          * an error.
 276          */
 277         if (p7->d.ptr == NULL) {
 278                 PKCS7error(PKCS7_R_NO_CONTENT);
 279                 return NULL;
 280         }
 281
 282         i = OBJ_obj2nid(p7->type);
 283         p7->state = PKCS7_S_HEADER;
 284
 285         switch (i) {
 286         case NID_pkcs7_signed:
 287                 md_sk = p7->d.sign->md_algs;
 288                 os = PKCS7_get_octet_string(p7->d.sign->contents);
 289                 break;
 290         case NID_pkcs7_signedAndEnveloped:
 291                 rsk = p7->d.signed_and_enveloped->recipientinfo;
 292                 md_sk = p7->d.signed_and_enveloped->md_algs;
 293                 xalg = p7->d.signed_and_enveloped->enc_data->algorithm;
 294                 evp_cipher = p7->d.signed_and_enveloped->enc_data->cipher;
 295                 if (evp_cipher == NULL) {
 296                         PKCS7error(PKCS7_R_CIPHER_NOT_INITIALIZED);
 297                         goto err;
 298                 }
 299                 break;
 300         case NID_pkcs7_enveloped:
 301                 rsk = p7->d.enveloped->recipientinfo;
 302                 xalg = p7->d.enveloped->enc_data->algorithm;
 303                 evp_cipher = p7->d.enveloped->enc_data->cipher;
 304                 if (evp_cipher == NULL) {
 305                         PKCS7error(PKCS7_R_CIPHER_NOT_INITIALIZED);
 306                         goto err;
 307                 }
 308                 break;
 309         case NID_pkcs7_digest:
 310                 xa = p7->d.digest->md;
 311                 os = PKCS7_get_octet_string(p7->d.digest->contents);
 312                 break;
 313         case NID_pkcs7_data:
 314                 break;
 315         default:
 316                 PKCS7error(PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
 317                 goto err;
 318         }
 319
 320         for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++)
 321                 if (!PKCS7_bio_add_digest(&out, sk_X509_ALGOR_value(md_sk, i)))
 322                         goto err;
 323
 324         if (xa && !PKCS7_bio_add_digest(&out, xa))
 325                 goto err;
 326
 327         if (evp_cipher != NULL) {
 328                 unsigned char key[EVP_MAX_KEY_LENGTH];
 329                 unsigned char iv[EVP_MAX_IV_LENGTH];
 330                 int keylen, ivlen;
 331                 EVP_CIPHER_CTX *ctx;
 332
 333                 if ((btmp = BIO_new(BIO_f_cipher())) == NULL) {
 334                         PKCS7error(ERR_R_BIO_LIB);
 335                         goto err;
 336                 }
 337                 BIO_get_cipher_ctx(btmp, &ctx);
 338                 keylen = EVP_CIPHER_key_length(evp_cipher);
 339                 ivlen = EVP_CIPHER_iv_length(evp_cipher);
 340                 xalg->algorithm = OBJ_nid2obj(EVP_CIPHER_type(evp_cipher));
 341                 if (ivlen > 0)
 342                         arc4random_buf(iv, ivlen);
 343                 if (EVP_CipherInit_ex(ctx, evp_cipher, NULL, NULL,
 344                     NULL, 1) <= 0)
 345                         goto err;
 346                 if (EVP_CIPHER_CTX_rand_key(ctx, key) <= 0)
 347                         goto err;
 348                 if (EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, 1) <= 0)
 349                         goto err;
 350
 351                 if (ivlen > 0) {
 352                         if (xalg->parameter == NULL) {
 353                                 xalg->parameter = ASN1_TYPE_new();
 354                                 if (xalg->parameter == NULL)
 355                                         goto err;
 356                         }
 357                         if (EVP_CIPHER_param_to_asn1(ctx, xalg->parameter) < 0)
 358                                 goto err;
 359                 }
 360
 361                 /* Lets do the pub key stuff :-) */
 362                 for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
 363                         ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
 364                         if (pkcs7_encode_rinfo(ri, key, keylen) <= 0)
 365                                 goto err;
 366                 }
 367                 explicit_bzero(key, keylen);
 368
 369                 if (out == NULL)
 370                         out = btmp;
 371                 else
 372                         BIO_push(out, btmp);
 373                 btmp = NULL;
 374         }
 375
 376         if (bio == NULL) {
 377                 if (PKCS7_is_detached(p7))
 378                         bio = BIO_new(BIO_s_null());
 379                 else if (os && os->length > 0)
 380                         bio = BIO_new_mem_buf(os->data, os->length);
 381                 if (bio == NULL) {
 382                         bio = BIO_new(BIO_s_mem());
 383                         if (bio == NULL)
 384                                 goto err;
 385                         BIO_set_mem_eof_return(bio, 0);
 386                 }
 387         }
 388         if (out)
 389                 BIO_push(out, bio);
 390         else
 391                 out = bio;
 392         bio = NULL;
 393         if (0) {
 394 err:
 395                 if (out != NULL)
 396                         BIO_free_all(out);
 397                 if (btmp != NULL)
 398                         BIO_free_all(btmp);
 399                 out = NULL;
 400         }
 401         return (out);
 402 }
 403
 404 static int
 405 pkcs7_cmp_ri(PKCS7_RECIP_INFO *ri, X509 *pcert)
 406 {
 407         int ret;
 408
 409         ret = X509_NAME_cmp(ri->issuer_and_serial->issuer,
 410             pcert->cert_info->issuer);
 411         if (ret)
 412                 return ret;
 413         return ASN1_STRING_cmp(pcert->cert_info->serialNumber,
 414             ri->issuer_and_serial->serial);
 415 }
 416
 417 /* int */
 418 BIO *
 419 PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 420 {
 421         int i, j;
 422         BIO *out = NULL, *btmp = NULL, *etmp = NULL, *bio = NULL;
 423         X509_ALGOR *xa;
 424         ASN1_OCTET_STRING *data_body = NULL;
 425         const EVP_MD *evp_md;
 426         const EVP_CIPHER *evp_cipher = NULL;
 427         EVP_CIPHER_CTX *evp_ctx = NULL;
 428         X509_ALGOR *enc_alg = NULL;
 429         STACK_OF(X509_ALGOR) *md_sk = NULL;
 430         STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
 431         PKCS7_RECIP_INFO *ri = NULL;
 432         unsigned char *ek = NULL, *tkey = NULL;
 433         int eklen = 0, tkeylen = 0;
 434
 435         if (p7 == NULL) {
 436                 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
 437                 return NULL;
 438         }
 439
 440         if (p7->d.ptr == NULL) {
 441                 PKCS7error(PKCS7_R_NO_CONTENT);
 442                 return NULL;
 443         }
 444
 445         i = OBJ_obj2nid(p7->type);
 446         p7->state = PKCS7_S_HEADER;
 447
 448         switch (i) {
 449         case NID_pkcs7_signed:
 450                 data_body = PKCS7_get_octet_string(p7->d.sign->contents);
 451                 md_sk = p7->d.sign->md_algs;
 452                 break;
 453         case NID_pkcs7_signedAndEnveloped:
 454                 rsk = p7->d.signed_and_enveloped->recipientinfo;
 455                 md_sk = p7->d.signed_and_enveloped->md_algs;
 456                 data_body = p7->d.signed_and_enveloped->enc_data->enc_data;
 457                 enc_alg = p7->d.signed_and_enveloped->enc_data->algorithm;
 458                 evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
 459                 if (evp_cipher == NULL) {
 460                         PKCS7error(PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
 461                         goto err;
 462                 }
 463                 break;
 464         case NID_pkcs7_enveloped:
 465                 rsk = p7->d.enveloped->recipientinfo;
 466                 enc_alg = p7->d.enveloped->enc_data->algorithm;
 467                 data_body = p7->d.enveloped->enc_data->enc_data;
 468                 evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
 469                 if (evp_cipher == NULL) {
 470                         PKCS7error(PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
 471                         goto err;
 472                 }
 473                 break;
 474         default:
 475                 PKCS7error(PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
 476                 goto err;
 477         }
 478
 479         /* We will be checking the signature */
 480         if (md_sk != NULL) {
 481                 for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++) {
 482                         xa = sk_X509_ALGOR_value(md_sk, i);
 483                         if ((btmp = BIO_new(BIO_f_md())) == NULL) {
 484                                 PKCS7error(ERR_R_BIO_LIB);
 485                                 goto err;
 486                         }
 487
 488                         j = OBJ_obj2nid(xa->algorithm);
 489                         evp_md = EVP_get_digestbynid(j);
 490                         if (evp_md == NULL) {
 491                                 PKCS7error(PKCS7_R_UNKNOWN_DIGEST_TYPE);
 492                                 goto err;
 493                         }
 494
 495                         BIO_set_md(btmp, evp_md);
 496                         if (out == NULL)
 497                                 out = btmp;
 498                         else
 499                                 BIO_push(out, btmp);
 500                         btmp = NULL;
 501                 }
 502         }
 503
 504         if (evp_cipher != NULL) {
 505                 if ((etmp = BIO_new(BIO_f_cipher())) == NULL) {
 506                         PKCS7error(ERR_R_BIO_LIB);
 507                         goto err;
 508                 }
 509
 510                 /* It was encrypted, we need to decrypt the secret key
 511                  * with the private key */
 512
 513                 /* Find the recipientInfo which matches the passed certificate
 514                  * (if any)
 515                  */
 516                 if (pcert) {
 517                         for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
 518                                 ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
 519                                 if (!pkcs7_cmp_ri(ri, pcert))
 520                                         break;
 521                                 ri = NULL;
 522                         }
 523                         if (ri == NULL) {
 524                                 PKCS7error(PKCS7_R_NO_RECIPIENT_MATCHES_CERTIFICATE);
 525                                 goto err;
 526                         }
 527                 }
 528
 529                 /* If we haven't got a certificate try each ri in turn */
 530                 if (pcert == NULL) {
 531                         /* Always attempt to decrypt all rinfo even
 532                          * after sucess as a defence against MMA timing
 533                          * attacks.
 534                          */
 535                         for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
 536                                 ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
 537
 538                                 if (pkcs7_decrypt_rinfo(&ek, &eklen,
 539                                     ri, pkey) < 0)
 540                                         goto err;
 541                                 ERR_clear_error();
 542                         }
 543                 } else {
 544                         /* Only exit on fatal errors, not decrypt failure */
 545                         if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey) < 0)
 546                                 goto err;
 547                         ERR_clear_error();
 548                 }
 549
 550                 evp_ctx = NULL;
 551                 BIO_get_cipher_ctx(etmp, &evp_ctx);
 552                 if (EVP_CipherInit_ex(evp_ctx, evp_cipher, NULL, NULL,
 553                     NULL, 0) <= 0)
 554                         goto err;
 555                 if (EVP_CIPHER_asn1_to_param(evp_ctx, enc_alg->parameter) < 0)
 556                         goto err;
 557                 /* Generate random key as MMA defence */
 558                 tkeylen = EVP_CIPHER_CTX_key_length(evp_ctx);
 559                 tkey = malloc(tkeylen);
 560                 if (!tkey)
 561                         goto err;
 562                 if (EVP_CIPHER_CTX_rand_key(evp_ctx, tkey) <= 0)
 563                         goto err;
 564                 if (ek == NULL) {
 565                         ek = tkey;
 566                         eklen = tkeylen;
 567                         tkey = NULL;
 568                 }
 569
 570                 if (eklen != EVP_CIPHER_CTX_key_length(evp_ctx)) {
 571                         /* Some S/MIME clients don't use the same key
 572                          * and effective key length. The key length is
 573                          * determined by the size of the decrypted RSA key.
 574                          */
 575                         if (!EVP_CIPHER_CTX_set_key_length(evp_ctx, eklen)) {
 576                                 /* Use random key as MMA defence */
 577                                 freezero(ek, eklen);
 578                                 ek = tkey;
 579                                 eklen = tkeylen;
 580                                 tkey = NULL;
 581                         }
 582                 }
 583                 /* Clear errors so we don't leak information useful in MMA */
 584                 ERR_clear_error();
 585                 if (EVP_CipherInit_ex(evp_ctx, NULL, NULL, ek, NULL, 0) <= 0)
 586                         goto err;
 587
 588                 freezero(ek, eklen);
 589                 ek = NULL;
 590                 freezero(tkey, tkeylen);
 591                 tkey = NULL;
 592
 593                 if (out == NULL)
 594                         out = etmp;
 595                 else
 596                         BIO_push(out, etmp);
 597                 etmp = NULL;
 598         }
 599
 600         if (PKCS7_is_detached(p7) || (in_bio != NULL)) {
 601                 bio = in_bio;
 602         } else {
 603                 if (data_body != NULL && data_body->length > 0)
 604                         bio = BIO_new_mem_buf(data_body->data, data_body->length);
 605                 else {
 606                         bio = BIO_new(BIO_s_mem());
 607                         BIO_set_mem_eof_return(bio, 0);
 608                 }
 609                 if (bio == NULL)
 610                         goto err;
 611         }
 612         BIO_push(out, bio);
 613
 614         if (0) {
 615 err:
 616                 freezero(ek, eklen);
 617                 freezero(tkey, tkeylen);
 618                 if (out != NULL)
 619                         BIO_free_all(out);
 620                 if (btmp != NULL)
 621                         BIO_free_all(btmp);
 622                 if (etmp != NULL)
 623                         BIO_free_all(etmp);
 624                 out = NULL;
 625         }
 626         return (out);
 627 }
 628
 629 static BIO *
 630 PKCS7_find_digest(EVP_MD_CTX **pmd, BIO *bio, int nid)
 631 {
 632         for (;;) {
 633                 bio = BIO_find_type(bio, BIO_TYPE_MD);
 634                 if (bio == NULL) {
 635                         PKCS7error(PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
 636                         return NULL;
 637                 }
 638                 BIO_get_md_ctx(bio, pmd);
 639                 if (*pmd == NULL) {
 640                         PKCS7error(ERR_R_INTERNAL_ERROR);
 641                         return NULL;
 642                 }
 643                 if (EVP_MD_CTX_type(*pmd) == nid)
 644                         return bio;
 645                 bio = BIO_next(bio);
 646         }
 647         return NULL;
 648 }
 649
 650 static int
 651 do_pkcs7_signed_attrib(PKCS7_SIGNER_INFO *si, EVP_MD_CTX *mctx)
 652 {
 653         unsigned char md_data[EVP_MAX_MD_SIZE];
 654         unsigned int md_len;
 655
 656         /* Add signing time if not already present */
 657         if (!PKCS7_get_signed_attribute(si, NID_pkcs9_signingTime)) {
 658                 if (!PKCS7_add0_attrib_signing_time(si, NULL)) {
 659                         PKCS7error(ERR_R_MALLOC_FAILURE);
 660                         return 0;
 661                 }
 662         }
 663
 664         /* Add digest */
 665         if (!EVP_DigestFinal_ex(mctx, md_data, &md_len)) {
 666                 PKCS7error(ERR_R_EVP_LIB);
 667                 return 0;
 668         }
 669         if (!PKCS7_add1_attrib_digest(si, md_data, md_len)) {
 670                 PKCS7error(ERR_R_MALLOC_FAILURE);
 671                 return 0;
 672         }
 673
 674         /* Now sign the attributes */
 675         if (!PKCS7_SIGNER_INFO_sign(si))
 676                 return 0;
 677
 678         return 1;
 679 }
 680
 681
 682 int
 683 PKCS7_dataFinal(PKCS7 *p7, BIO *bio)
 684 {
 685         int ret = 0;
 686         int i, j;
 687         BIO *btmp;
 688         PKCS7_SIGNER_INFO *si;
 689         EVP_MD_CTX *mdc, ctx_tmp;
 690         STACK_OF(X509_ATTRIBUTE) *sk;
 691         STACK_OF(PKCS7_SIGNER_INFO) *si_sk = NULL;
 692         ASN1_OCTET_STRING *os = NULL;
 693
 694         if (p7 == NULL) {
 695                 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
 696                 return 0;
 697         }
 698
 699         if (p7->d.ptr == NULL) {
 700                 PKCS7error(PKCS7_R_NO_CONTENT);
 701                 return 0;
 702         }
 703
 704         EVP_MD_CTX_init(&ctx_tmp);
 705         i = OBJ_obj2nid(p7->type);
 706         p7->state = PKCS7_S_HEADER;
 707
 708         switch (i) {
 709         case NID_pkcs7_data:
 710                 os = p7->d.data;
 711                 break;
 712         case NID_pkcs7_signedAndEnveloped:
 713                 /* XXX */
 714                 si_sk = p7->d.signed_and_enveloped->signer_info;
 715                 os = p7->d.signed_and_enveloped->enc_data->enc_data;
 716                 if (!os) {
 717                         os = ASN1_OCTET_STRING_new();
 718                         if (!os) {
 719                                 PKCS7error(ERR_R_MALLOC_FAILURE);
 720                                 goto err;
 721                         }
 722                         p7->d.signed_and_enveloped->enc_data->enc_data = os;
 723                 }
 724                 break;
 725         case NID_pkcs7_enveloped:
 726                 /* XXX */
 727                 os = p7->d.enveloped->enc_data->enc_data;
 728                 if (!os) {
 729                         os = ASN1_OCTET_STRING_new();
 730                         if (!os) {
 731                                 PKCS7error(ERR_R_MALLOC_FAILURE);
 732                                 goto err;
 733                         }
 734                         p7->d.enveloped->enc_data->enc_data = os;
 735                 }
 736                 break;
 737         case NID_pkcs7_signed:
 738                 si_sk = p7->d.sign->signer_info;
 739                 os = PKCS7_get_octet_string(p7->d.sign->contents);
 740                 if (!PKCS7_is_detached(p7) && os == NULL) {
 741                         PKCS7error(PKCS7_R_DECODE_ERROR);
 742                         goto err;
 743                 }
 744                 /* If detached data then the content is excluded */
 745                 if (PKCS7_type_is_data(p7->d.sign->contents) && p7->detached) {
 746                         ASN1_OCTET_STRING_free(os);
 747                         os = NULL;
 748                         p7->d.sign->contents->d.data = NULL;
 749                 }
 750                 break;
 751
 752         case NID_pkcs7_digest:
 753                 os = PKCS7_get_octet_string(p7->d.digest->contents);
 754                 if (os == NULL) {
 755                         PKCS7error(PKCS7_R_DECODE_ERROR);
 756                         goto err;
 757                 }
 758                 /* If detached data then the content is excluded */
 759                 if (PKCS7_type_is_data(p7->d.digest->contents) &&
 760                     p7->detached) {
 761                         ASN1_OCTET_STRING_free(os);
 762                         os = NULL;
 763                         p7->d.digest->contents->d.data = NULL;
 764                 }
 765                 break;
 766
 767         default:
 768                 PKCS7error(PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
 769                 goto err;
 770         }
 771
 772         if (si_sk != NULL) {
 773                 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(si_sk); i++) {
 774                         si = sk_PKCS7_SIGNER_INFO_value(si_sk, i);
 775                         if (si->pkey == NULL)
 776                                 continue;
 777
 778                         j = OBJ_obj2nid(si->digest_alg->algorithm);
 779
 780                         if ((btmp = PKCS7_find_digest(&mdc, bio, j)) == NULL)
 781                                 goto err;
 782
 783                         /* We now have the EVP_MD_CTX, lets do the
 784                          * signing. */
 785                         if (!EVP_MD_CTX_copy_ex(&ctx_tmp, mdc))
 786                                 goto err;
 787
 788                         sk = si->auth_attr;
 789
 790                         /* If there are attributes, we add the digest
 791                          * attribute and only sign the attributes */
 792                         if (sk_X509_ATTRIBUTE_num(sk) > 0) {
 793                                 if (!do_pkcs7_signed_attrib(si, &ctx_tmp))
 794                                         goto err;
 795                         } else {
 796                                 unsigned char *abuf = NULL;
 797                                 unsigned int abuflen;
 798                                 abuflen = EVP_PKEY_size(si->pkey);
 799                                 abuf = malloc(abuflen);
 800                                 if (!abuf)
 801                                         goto err;
 802
 803                                 if (!EVP_SignFinal(&ctx_tmp, abuf, &abuflen,
 804                                     si->pkey)) {
 805                                         PKCS7error(ERR_R_EVP_LIB);
 806                                         goto err;
 807                                 }
 808                                 ASN1_STRING_set0(si->enc_digest, abuf, abuflen);
 809                         }
 810                 }
 811         } else if (i == NID_pkcs7_digest) {
 812                 unsigned char md_data[EVP_MAX_MD_SIZE];
 813                 unsigned int md_len;
 814
 815                 if (!PKCS7_find_digest(&mdc, bio,
 816                     OBJ_obj2nid(p7->d.digest->md->algorithm)))
 817                         goto err;
 818                 if (!EVP_DigestFinal_ex(mdc, md_data, &md_len))
 819                         goto err;
 820                 if (ASN1_STRING_set(p7->d.digest->digest, md_data,
 821                     md_len) == 0)
 822                         goto err;
 823         }
 824
 825         if (!PKCS7_is_detached(p7)) {
 826                 /*
 827                  * NOTE: only reach os == NULL here because detached
 828                  * digested data support is broken?
 829                  */
 830                 if (os == NULL)
 831                         goto err;
 832                 if (!(os->flags & ASN1_STRING_FLAG_NDEF)) {
 833                         char *cont;
 834                         long contlen;
 835
 836                         btmp = BIO_find_type(bio, BIO_TYPE_MEM);
 837                         if (btmp == NULL) {
 838                                 PKCS7error(PKCS7_R_UNABLE_TO_FIND_MEM_BIO);
 839                                 goto err;
 840                         }
 841                         contlen = BIO_get_mem_data(btmp, &cont);
 842                         /*
 843                          * Mark the BIO read only then we can use its copy
 844                          * of the data instead of making an extra copy.
 845                          */
 846                         BIO_set_flags(btmp, BIO_FLAGS_MEM_RDONLY);
 847                         BIO_set_mem_eof_return(btmp, 0);
 848                         ASN1_STRING_set0(os, (unsigned char *)cont, contlen);
 849                 }
 850         }
 851         ret = 1;
 852 err:
 853         EVP_MD_CTX_cleanup(&ctx_tmp);
 854         return (ret);
 855 }
 856
 857 int
 858 PKCS7_SIGNER_INFO_sign(PKCS7_SIGNER_INFO *si)
 859 {
 860         EVP_MD_CTX mctx;
 861         EVP_PKEY_CTX *pctx;
 862         unsigned char *abuf = NULL;
 863         int alen;
 864         size_t siglen;
 865         const EVP_MD *md = NULL;
 866
 867         md = EVP_get_digestbyobj(si->digest_alg->algorithm);
 868         if (md == NULL)
 869                 return 0;
 870
 871         EVP_MD_CTX_init(&mctx);
 872         if (EVP_DigestSignInit(&mctx, &pctx, md, NULL, si->pkey) <= 0)
 873                 goto err;
 874
 875         if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
 876             EVP_PKEY_CTRL_PKCS7_SIGN, 0, si) <= 0) {
 877                 PKCS7error(PKCS7_R_CTRL_ERROR);
 878                 goto err;
 879         }
 880
 881         alen = ASN1_item_i2d((ASN1_VALUE *)si->auth_attr, &abuf,
 882             &PKCS7_ATTR_SIGN_it);
 883         if (!abuf)
 884                 goto err;
 885         if (EVP_DigestSignUpdate(&mctx, abuf, alen) <= 0)
 886                 goto err;
 887         free(abuf);
 888         abuf = NULL;
 889         if (EVP_DigestSignFinal(&mctx, NULL, &siglen) <= 0)
 890                 goto err;
 891         abuf = malloc(siglen);
 892         if (!abuf)
 893                 goto err;
 894         if (EVP_DigestSignFinal(&mctx, abuf, &siglen) <= 0)
 895                 goto err;
 896
 897         if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
 898             EVP_PKEY_CTRL_PKCS7_SIGN, 1, si) <= 0) {
 899                 PKCS7error(PKCS7_R_CTRL_ERROR);
 900                 goto err;
 901         }
 902
 903         EVP_MD_CTX_cleanup(&mctx);
 904
 905         ASN1_STRING_set0(si->enc_digest, abuf, siglen);
 906
 907         return 1;
 908
 909 err:
 910         free(abuf);
 911         EVP_MD_CTX_cleanup(&mctx);
 912         return 0;
 913 }
 914
 915 int
 916 PKCS7_dataVerify(X509_STORE *cert_store, X509_STORE_CTX *ctx, BIO *bio,
 917     PKCS7 *p7, PKCS7_SIGNER_INFO *si)
 918 {
 919         PKCS7_ISSUER_AND_SERIAL *ias;
 920         int ret = 0, i;
 921         STACK_OF(X509) *cert;
 922         X509 *x509;
 923
 924         if (p7 == NULL) {
 925                 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
 926                 return 0;
 927         }
 928
 929         if (p7->d.ptr == NULL) {
 930                 PKCS7error(PKCS7_R_NO_CONTENT);
 931                 return 0;
 932         }
 933
 934         if (PKCS7_type_is_signed(p7)) {
 935                 cert = p7->d.sign->cert;
 936         } else if (PKCS7_type_is_signedAndEnveloped(p7)) {
 937                 cert = p7->d.signed_and_enveloped->cert;
 938         } else {
 939                 PKCS7error(PKCS7_R_WRONG_PKCS7_TYPE);
 940                 goto err;
 941         }
 942         /* XXXX */
 943         ias = si->issuer_and_serial;
 944
 945         x509 = X509_find_by_issuer_and_serial(cert, ias->issuer, ias->serial);
 946
 947         /* were we able to find the cert in passed to us */
 948         if (x509 == NULL) {
 949                 PKCS7error(PKCS7_R_UNABLE_TO_FIND_CERTIFICATE);
 950                 goto err;
 951         }
 952
 953         /* Lets verify */
 954         if (!X509_STORE_CTX_init(ctx, cert_store, x509, cert)) {
 955                 PKCS7error(ERR_R_X509_LIB);
 956                 goto err;
 957         }
 958         if (X509_STORE_CTX_set_purpose(ctx, X509_PURPOSE_SMIME_SIGN) == 0) {
 959                 X509_STORE_CTX_cleanup(ctx);
 960                 goto err;
 961         }
 962         i = X509_verify_cert(ctx);
 963         if (i <= 0) {
 964                 PKCS7error(ERR_R_X509_LIB);
 965                 X509_STORE_CTX_cleanup(ctx);
 966                 goto err;
 967         }
 968         X509_STORE_CTX_cleanup(ctx);
 969
 970         return PKCS7_signatureVerify(bio, p7, si, x509);
 971 err:
 972
 973         return ret;
 974 }
 975
 976 int
 977 PKCS7_signatureVerify(BIO *bio, PKCS7 *p7, PKCS7_SIGNER_INFO *si, X509 *x509)
 978 {
 979         ASN1_OCTET_STRING *os;
 980         EVP_MD_CTX mdc_tmp, *mdc;
 981         int ret = 0, i;
 982         int md_type;
 983         STACK_OF(X509_ATTRIBUTE) *sk;
 984         BIO *btmp;
 985         EVP_PKEY *pkey;
 986
 987         EVP_MD_CTX_init(&mdc_tmp);
 988
 989         if (!PKCS7_type_is_signed(p7) &&
 990             !PKCS7_type_is_signedAndEnveloped(p7)) {
 991                 PKCS7error(PKCS7_R_WRONG_PKCS7_TYPE);
 992                 goto err;
 993         }
 994
 995         md_type = OBJ_obj2nid(si->digest_alg->algorithm);
 996
 997         btmp = bio;
 998         for (;;) {
 999                 if ((btmp == NULL) ||
1000                     ((btmp = BIO_find_type(btmp, BIO_TYPE_MD)) == NULL)) {
1001                         PKCS7error(PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
1002                         goto err;
1003                 }
1004                 BIO_get_md_ctx(btmp, &mdc);
1005                 if (mdc == NULL) {
1006                         PKCS7error(ERR_R_INTERNAL_ERROR);
1007                         goto err;
1008                 }
1009                 if (EVP_MD_CTX_type(mdc) == md_type)
1010                         break;
1011                 /* Workaround for some broken clients that put the signature
1012                  * OID instead of the digest OID in digest_alg->algorithm
1013                  */
1014                 if (EVP_MD_pkey_type(EVP_MD_CTX_md(mdc)) == md_type)
1015                         break;
1016                 btmp = BIO_next(btmp);
1017         }
1018
1019         /* mdc is the digest ctx that we want, unless there are attributes,
1020          * in which case the digest is the signed attributes */
1021         if (!EVP_MD_CTX_copy_ex(&mdc_tmp, mdc))
1022                 goto err;
1023
1024         sk = si->auth_attr;
1025         if ((sk != NULL) && (sk_X509_ATTRIBUTE_num(sk) != 0)) {
1026                 unsigned char md_dat[EVP_MAX_MD_SIZE], *abuf = NULL;
1027                 unsigned int md_len;
1028                 int alen;
1029                 ASN1_OCTET_STRING *message_digest;
1030
1031                 if (!EVP_DigestFinal_ex(&mdc_tmp, md_dat, &md_len))
1032                         goto err;
1033                 message_digest = PKCS7_digest_from_attributes(sk);
1034                 if (!message_digest) {
1035                         PKCS7error(PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
1036                         goto err;
1037                 }
1038                 if ((message_digest->length != (int)md_len) ||
1039                     (memcmp(message_digest->data, md_dat, md_len))) {
1040                         PKCS7error(PKCS7_R_DIGEST_FAILURE);
1041                         ret = -1;
1042                         goto err;
1043                 }
1044
1045                 if (!EVP_VerifyInit_ex(&mdc_tmp, EVP_get_digestbynid(md_type),
1046                     NULL))
1047                         goto err;
1048
1049                 alen = ASN1_item_i2d((ASN1_VALUE *)sk, &abuf,
1050                     &PKCS7_ATTR_VERIFY_it);
1051                 if (alen <= 0) {
1052                         PKCS7error(ERR_R_ASN1_LIB);
1053                         ret = -1;
1054                         goto err;
1055                 }
1056                 if (!EVP_VerifyUpdate(&mdc_tmp, abuf, alen))
1057                         goto err;
1058
1059                 free(abuf);
1060         }
1061
1062         os = si->enc_digest;
1063         pkey = X509_get_pubkey(x509);
1064         if (!pkey) {
1065                 ret = -1;
1066                 goto err;
1067         }
1068
1069         i = EVP_VerifyFinal(&mdc_tmp, os->data, os->length, pkey);
1070         EVP_PKEY_free(pkey);
1071         if (i <= 0) {
1072                 PKCS7error(PKCS7_R_SIGNATURE_FAILURE);
1073                 ret = -1;
1074                 goto err;
1075         } else
1076                 ret = 1;
1077 err:
1078         EVP_MD_CTX_cleanup(&mdc_tmp);
1079         return (ret);
1080 }
1081
1082 PKCS7_ISSUER_AND_SERIAL *
1083 PKCS7_get_issuer_and_serial(PKCS7 *p7, int idx)
1084 {
1085         STACK_OF(PKCS7_RECIP_INFO) *rsk;
1086         PKCS7_RECIP_INFO *ri;
1087         int i;
1088
1089         i = OBJ_obj2nid(p7->type);
1090         if (i != NID_pkcs7_signedAndEnveloped)
1091                 return NULL;
1092         if (p7->d.signed_and_enveloped == NULL)
1093                 return NULL;
1094         rsk = p7->d.signed_and_enveloped->recipientinfo;
1095         if (rsk == NULL)
1096                 return NULL;
1097         ri = sk_PKCS7_RECIP_INFO_value(rsk, 0);
1098         if (sk_PKCS7_RECIP_INFO_num(rsk) <= idx)
1099                 return (NULL);
1100         ri = sk_PKCS7_RECIP_INFO_value(rsk, idx);
1101         return (ri->issuer_and_serial);
1102 }
1103
1104 ASN1_TYPE *
1105 PKCS7_get_signed_attribute(PKCS7_SIGNER_INFO *si, int nid)
1106 {
1107         return (get_attribute(si->auth_attr, nid));
1108 }
1109
1110 ASN1_TYPE *
1111 PKCS7_get_attribute(PKCS7_SIGNER_INFO *si, int nid)
1112 {
1113         return (get_attribute(si->unauth_attr, nid));
1114 }
1115
1116 static ASN1_TYPE *
1117 get_attribute(STACK_OF(X509_ATTRIBUTE) *sk, int nid)
1118 {
1119         int i;
1120         X509_ATTRIBUTE *xa;
1121         ASN1_OBJECT *o;
1122
1123         o = OBJ_nid2obj(nid);
1124         if (!o || !sk)
1125                 return (NULL);
1126         for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
1127                 xa = sk_X509_ATTRIBUTE_value(sk, i);
1128                 if (OBJ_cmp(xa->object, o) == 0) {
1129                         if (!xa->single && sk_ASN1_TYPE_num(xa->value.set))
1130                                 return (sk_ASN1_TYPE_value(xa->value.set, 0));
1131                         else
1132                                 return (NULL);
1133                 }
1134         }
1135         return (NULL);
1136 }
1137
1138 ASN1_OCTET_STRING *
1139 PKCS7_digest_from_attributes(STACK_OF(X509_ATTRIBUTE) *sk)
1140 {
1141         ASN1_TYPE *astype;
1142
1143         if (!(astype = get_attribute(sk, NID_pkcs9_messageDigest)))
1144                 return NULL;
1145         if (astype->type != V_ASN1_OCTET_STRING)
1146                 return NULL;
1147         return astype->value.octet_string;
1148 }
1149
1150 int
1151 PKCS7_set_signed_attributes(PKCS7_SIGNER_INFO *p7si,
1152     STACK_OF(X509_ATTRIBUTE) *sk)
1153 {
1154         int i;
1155
1156         if (p7si->auth_attr != NULL)
1157                 sk_X509_ATTRIBUTE_pop_free(p7si->auth_attr,
1158                     X509_ATTRIBUTE_free);
1159         p7si->auth_attr = sk_X509_ATTRIBUTE_dup(sk);
1160         if (p7si->auth_attr == NULL)
1161                 return 0;
1162         for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
1163                 if ((sk_X509_ATTRIBUTE_set(p7si->auth_attr, i,
1164                     X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value(sk, i))))
1165                     == NULL)
1166                         return (0);
1167         }
1168         return (1);
1169 }
1170
1171 int
1172 PKCS7_set_attributes(PKCS7_SIGNER_INFO *p7si, STACK_OF(X509_ATTRIBUTE) *sk)
1173 {
1174         int i;
1175
1176         if (p7si->unauth_attr != NULL)
1177                 sk_X509_ATTRIBUTE_pop_free(p7si->unauth_attr,
1178                     X509_ATTRIBUTE_free);
1179         p7si->unauth_attr = sk_X509_ATTRIBUTE_dup(sk);
1180         if (p7si->unauth_attr == NULL)
1181                 return 0;
1182         for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
1183                 if ((sk_X509_ATTRIBUTE_set(p7si->unauth_attr, i,
1184                     X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value(sk, i))))
1185                     == NULL)
1186                         return (0);
1187         }
1188         return (1);
1189 }
1190
1191 int
1192 PKCS7_add_signed_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype,
1193     void *value)
1194 {
1195         return (add_attribute(&(p7si->auth_attr), nid, atrtype, value));
1196 }
1197
1198 int
1199 PKCS7_add_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype, void *value)
1200 {
1201         return (add_attribute(&(p7si->unauth_attr), nid, atrtype, value));
1202 }
1203
1204 static int
1205 add_attribute(STACK_OF(X509_ATTRIBUTE) **sk, int nid, int atrtype, void *value)
1206 {
1207         X509_ATTRIBUTE *attr = NULL;
1208
1209         if (*sk == NULL) {
1210                 *sk = sk_X509_ATTRIBUTE_new_null();
1211                 if (*sk == NULL)
1212                         return 0;
1213 new_attrib:
1214                 if (!(attr = X509_ATTRIBUTE_create(nid, atrtype, value)))
1215                         return 0;
1216                 if (!sk_X509_ATTRIBUTE_push(*sk, attr)) {
1217                         X509_ATTRIBUTE_free(attr);
1218                         return 0;
1219                 }
1220         } else {
1221                 int i;
1222
1223                 for (i = 0; i < sk_X509_ATTRIBUTE_num(*sk); i++) {
1224                         attr = sk_X509_ATTRIBUTE_value(*sk, i);
1225                         if (OBJ_obj2nid(attr->object) == nid) {
1226                                 X509_ATTRIBUTE_free(attr);
1227                                 attr = X509_ATTRIBUTE_create(nid, atrtype,
1228                                     value);
1229                                 if (attr == NULL)
1230                                         return 0;
1231                                 if (!sk_X509_ATTRIBUTE_set(*sk, i, attr)) {
1232                                         X509_ATTRIBUTE_free(attr);
1233                                         return 0;
1234                                 }
1235                                 goto end;
1236                         }
1237                 }
1238                 goto new_attrib;
1239         }
1240 end:
1241         return (1);
1242 }