lib/libcrypto/pkcs7/pk7_smime.c

   1 /* $OpenBSD: pk7_smime.c,v 1.22 2017/01/29 17:49:23 beck Exp $ */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 1999-2004 The OpenSSL Project.  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
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 /* Simple PKCS#7 processing functions */
  60
  61 #include <stdio.h>
  62
  63 #include <openssl/err.h>
  64 #include <openssl/x509.h>
  65 #include <openssl/x509v3.h>
  66
  67 static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si);
  68
  69 PKCS7 *
  70 PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs, BIO *data,
  71     int flags)
  72 {
  73         PKCS7 *p7;
  74         int i;
  75
  76         if (!(p7 = PKCS7_new())) {
  77                 PKCS7error(ERR_R_MALLOC_FAILURE);
  78                 return NULL;
  79         }
  80
  81         if (!PKCS7_set_type(p7, NID_pkcs7_signed))
  82                 goto err;
  83
  84         if (!PKCS7_content_new(p7, NID_pkcs7_data))
  85                 goto err;
  86
  87         if (pkey && !PKCS7_sign_add_signer(p7, signcert, pkey, NULL, flags)) {
  88                 PKCS7error(PKCS7_R_PKCS7_ADD_SIGNER_ERROR);
  89                 goto err;
  90         }
  91
  92         if (!(flags & PKCS7_NOCERTS)) {
  93                 for (i = 0; i < sk_X509_num(certs); i++) {
  94                         if (!PKCS7_add_certificate(p7, sk_X509_value(certs, i)))
  95                                 goto err;
  96                 }
  97         }
  98
  99         if (flags & PKCS7_DETACHED)
 100                 PKCS7_set_detached(p7, 1);
 101
 102         if (flags & (PKCS7_STREAM|PKCS7_PARTIAL))
 103                 return p7;
 104
 105         if (PKCS7_final(p7, data, flags))
 106                 return p7;
 107
 108 err:
 109         PKCS7_free(p7);
 110         return NULL;
 111 }
 112
 113 int
 114 PKCS7_final(PKCS7 *p7, BIO *data, int flags)
 115 {
 116         BIO *p7bio;
 117         int ret = 0;
 118
 119         if (!(p7bio = PKCS7_dataInit(p7, NULL))) {
 120                 PKCS7error(ERR_R_MALLOC_FAILURE);
 121                 return 0;
 122         }
 123
 124         SMIME_crlf_copy(data, p7bio, flags);
 125
 126         (void)BIO_flush(p7bio);
 127
 128         if (!PKCS7_dataFinal(p7, p7bio)) {
 129                 PKCS7error(PKCS7_R_PKCS7_DATASIGN);
 130                 goto err;
 131         }
 132
 133         ret = 1;
 134
 135 err:
 136         BIO_free_all(p7bio);
 137
 138         return ret;
 139 }
 140
 141 /* Check to see if a cipher exists and if so add S/MIME capabilities */
 142
 143 static int
 144 add_cipher_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
 145 {
 146         if (EVP_get_cipherbynid(nid))
 147                 return PKCS7_simple_smimecap(sk, nid, arg);
 148         return 1;
 149 }
 150
 151 static int
 152 add_digest_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
 153 {
 154         if (EVP_get_digestbynid(nid))
 155                 return PKCS7_simple_smimecap(sk, nid, arg);
 156         return 1;
 157 }
 158
 159 PKCS7_SIGNER_INFO *
 160 PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert, EVP_PKEY *pkey,
 161     const EVP_MD *md, int flags)
 162 {
 163         PKCS7_SIGNER_INFO *si = NULL;
 164         STACK_OF(X509_ALGOR) *smcap = NULL;
 165
 166         if (!X509_check_private_key(signcert, pkey)) {
 167                 PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
 168                 return NULL;
 169         }
 170
 171         if (!(si = PKCS7_add_signature(p7, signcert, pkey, md))) {
 172                 PKCS7error(PKCS7_R_PKCS7_ADD_SIGNATURE_ERROR);
 173                 return NULL;
 174         }
 175
 176         if (!(flags & PKCS7_NOCERTS)) {
 177                 if (!PKCS7_add_certificate(p7, signcert))
 178                         goto err;
 179         }
 180
 181         if (!(flags & PKCS7_NOATTR)) {
 182                 if (!PKCS7_add_attrib_content_type(si, NULL))
 183                         goto err;
 184                 /* Add SMIMECapabilities */
 185                 if (!(flags & PKCS7_NOSMIMECAP)) {
 186                         if (!(smcap = sk_X509_ALGOR_new_null())) {
 187                                 PKCS7error(ERR_R_MALLOC_FAILURE);
 188                                 goto err;
 189                         }
 190                         if (!add_cipher_smcap(smcap, NID_aes_256_cbc, -1) ||
 191                             !add_digest_smcap(smcap, NID_id_GostR3411_94, -1) ||
 192                             !add_digest_smcap(smcap, NID_id_tc26_gost3411_2012_256, -1) ||
 193                             !add_digest_smcap(smcap, NID_id_tc26_gost3411_2012_512, -1) ||
 194                             !add_cipher_smcap(smcap, NID_id_Gost28147_89, -1) ||
 195                             !add_cipher_smcap(smcap, NID_aes_192_cbc, -1) ||
 196                             !add_cipher_smcap(smcap, NID_aes_128_cbc, -1) ||
 197                             !add_cipher_smcap(smcap, NID_des_ede3_cbc, -1) ||
 198                             !add_cipher_smcap(smcap, NID_rc2_cbc, 128) ||
 199                             !add_cipher_smcap(smcap, NID_rc2_cbc, 64) ||
 200                             !add_cipher_smcap(smcap, NID_des_cbc, -1) ||
 201                             !add_cipher_smcap(smcap, NID_rc2_cbc, 40) ||
 202                             !PKCS7_add_attrib_smimecap(si, smcap))
 203                                 goto err;
 204                         sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
 205                         smcap = NULL;
 206                 }
 207                 if (flags & PKCS7_REUSE_DIGEST) {
 208                         if (!pkcs7_copy_existing_digest(p7, si))
 209                                 goto err;
 210                         if (!(flags & PKCS7_PARTIAL) &&
 211                             !PKCS7_SIGNER_INFO_sign(si))
 212                                 goto err;
 213                 }
 214         }
 215         return si;
 216
 217 err:
 218         if (smcap)
 219                 sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
 220         return NULL;
 221 }
 222
 223 /* Search for a digest matching SignerInfo digest type and if found
 224  * copy across.
 225  */
 226
 227 static int
 228 pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si)
 229 {
 230         int i;
 231         STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 232         PKCS7_SIGNER_INFO *sitmp;
 233         ASN1_OCTET_STRING *osdig = NULL;
 234
 235         sinfos = PKCS7_get_signer_info(p7);
 236         for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 237                 sitmp = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 238                 if (si == sitmp)
 239                         break;
 240                 if (sk_X509_ATTRIBUTE_num(sitmp->auth_attr) <= 0)
 241                         continue;
 242                 if (!OBJ_cmp(si->digest_alg->algorithm,
 243                     sitmp->digest_alg->algorithm)) {
 244                         osdig = PKCS7_digest_from_attributes(sitmp->auth_attr);
 245                         break;
 246                 }
 247
 248         }
 249
 250         if (osdig)
 251                 return PKCS7_add1_attrib_digest(si, osdig->data, osdig->length);
 252
 253         PKCS7error(PKCS7_R_NO_MATCHING_DIGEST_TYPE_FOUND);
 254         return 0;
 255 }
 256
 257 int
 258 PKCS7_verify(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store, BIO *indata,
 259     BIO *out, int flags)
 260 {
 261         STACK_OF(X509) *signers;
 262         X509 *signer;
 263         STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 264         PKCS7_SIGNER_INFO *si;
 265         X509_STORE_CTX cert_ctx;
 266         char buf[4096];
 267         int i, j = 0, k, ret = 0;
 268         BIO *p7bio;
 269         BIO *tmpin, *tmpout;
 270
 271         if (!p7) {
 272                 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
 273                 return 0;
 274         }
 275
 276         if (!PKCS7_type_is_signed(p7)) {
 277                 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE);
 278                 return 0;
 279         }
 280
 281         /* Check for no data and no content: no data to verify signature */
 282         if (PKCS7_get_detached(p7) && !indata) {
 283                 PKCS7error(PKCS7_R_NO_CONTENT);
 284                 return 0;
 285         }
 286
 287         /*
 288          * Very old Netscape illegally included empty content with
 289          * a detached signature.  Very old users should upgrade.
 290          */
 291         /* Check for data and content: two sets of data */
 292         if (!PKCS7_get_detached(p7) && indata) {
 293                 PKCS7error(PKCS7_R_CONTENT_AND_DATA_PRESENT);
 294                 return 0;
 295         }
 296
 297         sinfos = PKCS7_get_signer_info(p7);
 298
 299         if (!sinfos || !sk_PKCS7_SIGNER_INFO_num(sinfos)) {
 300                 PKCS7error(PKCS7_R_NO_SIGNATURES_ON_DATA);
 301                 return 0;
 302         }
 303
 304
 305         signers = PKCS7_get0_signers(p7, certs, flags);
 306
 307         if (!signers)
 308                 return 0;
 309
 310         /* Now verify the certificates */
 311
 312         if (!(flags & PKCS7_NOVERIFY))
 313                 for (k = 0; k < sk_X509_num(signers); k++) {
 314                         signer = sk_X509_value (signers, k);
 315                         if  (!(flags & PKCS7_NOCHAIN)) {
 316                                 if (!X509_STORE_CTX_init(&cert_ctx, store,
 317                                     signer, p7->d.sign->cert)) {
 318                                         PKCS7error(ERR_R_X509_LIB);
 319                                         sk_X509_free(signers);
 320                                         return 0;
 321                                 }
 322                                 if (X509_STORE_CTX_set_default(&cert_ctx,
 323                                     "smime_sign") == 0) {
 324                                         sk_X509_free(signers);
 325                                         return 0;
 326                                 }
 327                         } else if (!X509_STORE_CTX_init(&cert_ctx, store,
 328                             signer, NULL)) {
 329                                 PKCS7error(ERR_R_X509_LIB);
 330                                 sk_X509_free(signers);
 331                                 return 0;
 332                         }
 333                         if (!(flags & PKCS7_NOCRL))
 334                                 X509_STORE_CTX_set0_crls(&cert_ctx, p7->d.sign->crl);
 335                         i = X509_verify_cert(&cert_ctx);
 336                         if (i <= 0)
 337                                 j = X509_STORE_CTX_get_error(&cert_ctx);
 338                         X509_STORE_CTX_cleanup(&cert_ctx);
 339                         if (i <= 0) {
 340                                 PKCS7error(PKCS7_R_CERTIFICATE_VERIFY_ERROR);
 341                                 ERR_asprintf_error_data("Verify error:%s",
 342                                     X509_verify_cert_error_string(j));
 343                                 sk_X509_free(signers);
 344                                 return 0;
 345                         }
 346                         /* Check for revocation status here */
 347                 }
 348
 349         /*
 350          * Performance optimization: if the content is a memory BIO then
 351          * store its contents in a temporary read only memory BIO. This
 352          * avoids potentially large numbers of slow copies of data which will
 353          * occur when reading from a read write memory BIO when signatures
 354          * are calculated.
 355          */
 356         if (indata && (BIO_method_type(indata) == BIO_TYPE_MEM)) {
 357                 char *ptr;
 358                 long len;
 359
 360                 len = BIO_get_mem_data(indata, &ptr);
 361                 tmpin = BIO_new_mem_buf(ptr, len);
 362                 if (tmpin == NULL) {
 363                         PKCS7error(ERR_R_MALLOC_FAILURE);
 364                         return 0;
 365                 }
 366         } else
 367                 tmpin = indata;
 368
 369
 370         if (!(p7bio = PKCS7_dataInit(p7, tmpin)))
 371                 goto err;
 372
 373         if (flags & PKCS7_TEXT) {
 374                 if (!(tmpout = BIO_new(BIO_s_mem()))) {
 375                         PKCS7error(ERR_R_MALLOC_FAILURE);
 376                         goto err;
 377                 }
 378                 BIO_set_mem_eof_return(tmpout, 0);
 379         } else
 380                 tmpout = out;
 381
 382         /* We now have to 'read' from p7bio to calculate digests etc. */
 383         for (;;) {
 384                 i = BIO_read(p7bio, buf, sizeof(buf));
 385                 if (i <= 0)
 386                         break;
 387                 if (tmpout)
 388                         BIO_write(tmpout, buf, i);
 389         }
 390
 391         if (flags & PKCS7_TEXT) {
 392                 if (!SMIME_text(tmpout, out)) {
 393                         PKCS7error(PKCS7_R_SMIME_TEXT_ERROR);
 394                         BIO_free(tmpout);
 395                         goto err;
 396                 }
 397                 BIO_free(tmpout);
 398         }
 399
 400         /* Now Verify All Signatures */
 401         if (!(flags & PKCS7_NOSIGS))
 402                 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 403                         si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 404                         signer = sk_X509_value (signers, i);
 405                         j = PKCS7_signatureVerify(p7bio, p7, si, signer);
 406                         if (j <= 0) {
 407                                 PKCS7error(PKCS7_R_SIGNATURE_FAILURE);
 408                                 goto err;
 409                         }
 410                 }
 411
 412         ret = 1;
 413
 414 err:
 415         if (tmpin == indata) {
 416                 if (indata)
 417                         BIO_pop(p7bio);
 418         }
 419         BIO_free_all(p7bio);
 420         sk_X509_free(signers);
 421
 422         return ret;
 423 }
 424
 425 STACK_OF(X509) *
 426 PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs, int flags)
 427 {
 428         STACK_OF(X509) *signers;
 429         STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 430         PKCS7_SIGNER_INFO *si;
 431         PKCS7_ISSUER_AND_SERIAL *ias;
 432         X509 *signer;
 433         int i;
 434
 435         if (!p7) {
 436                 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
 437                 return NULL;
 438         }
 439
 440         if (!PKCS7_type_is_signed(p7)) {
 441                 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE);
 442                 return NULL;
 443         }
 444
 445         /* Collect all the signers together */
 446         sinfos = PKCS7_get_signer_info(p7);
 447         if (sk_PKCS7_SIGNER_INFO_num(sinfos) <= 0) {
 448                 PKCS7error(PKCS7_R_NO_SIGNERS);
 449                 return 0;
 450         }
 451
 452         if (!(signers = sk_X509_new_null())) {
 453                 PKCS7error(ERR_R_MALLOC_FAILURE);
 454                 return NULL;
 455         }
 456
 457         for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 458                 si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 459                 ias = si->issuer_and_serial;
 460                 signer = NULL;
 461                 /* If any certificates passed they take priority */
 462                 if (certs)
 463                         signer = X509_find_by_issuer_and_serial (certs,
 464                             ias->issuer, ias->serial);
 465                 if (!signer && !(flags & PKCS7_NOINTERN) && p7->d.sign->cert)
 466                         signer =
 467                             X509_find_by_issuer_and_serial(p7->d.sign->cert,
 468                               ias->issuer, ias->serial);
 469                 if (!signer) {
 470                         PKCS7error(PKCS7_R_SIGNER_CERTIFICATE_NOT_FOUND);
 471                         sk_X509_free(signers);
 472                         return 0;
 473                 }
 474
 475                 if (!sk_X509_push(signers, signer)) {
 476                         sk_X509_free(signers);
 477                         return NULL;
 478                 }
 479         }
 480         return signers;
 481 }
 482
 483 /* Build a complete PKCS#7 enveloped data */
 484
 485 PKCS7 *
 486 PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher,
 487     int flags)
 488 {
 489         PKCS7 *p7;
 490         BIO *p7bio = NULL;
 491         int i;
 492         X509 *x509;
 493
 494         if (!(p7 = PKCS7_new())) {
 495                 PKCS7error(ERR_R_MALLOC_FAILURE);
 496                 return NULL;
 497         }
 498
 499         if (!PKCS7_set_type(p7, NID_pkcs7_enveloped))
 500                 goto err;
 501         if (!PKCS7_set_cipher(p7, cipher)) {
 502                 PKCS7error(PKCS7_R_ERROR_SETTING_CIPHER);
 503                 goto err;
 504         }
 505
 506         for (i = 0; i < sk_X509_num(certs); i++) {
 507                 x509 = sk_X509_value(certs, i);
 508                 if (!PKCS7_add_recipient(p7, x509)) {
 509                         PKCS7error(PKCS7_R_ERROR_ADDING_RECIPIENT);
 510                         goto err;
 511                 }
 512         }
 513
 514         if (flags & PKCS7_STREAM)
 515                 return p7;
 516
 517         if (PKCS7_final(p7, in, flags))
 518                 return p7;
 519
 520 err:
 521         BIO_free_all(p7bio);
 522         PKCS7_free(p7);
 523         return NULL;
 524 }
 525
 526 int
 527 PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags)
 528 {
 529         BIO *tmpmem;
 530         int ret, i;
 531         char buf[4096];
 532
 533         if (!p7) {
 534                 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
 535                 return 0;
 536         }
 537
 538         if (!PKCS7_type_is_enveloped(p7)) {
 539                 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE);
 540                 return 0;
 541         }
 542
 543         if (cert && !X509_check_private_key(cert, pkey)) {
 544                 PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
 545                 return 0;
 546         }
 547
 548         if (!(tmpmem = PKCS7_dataDecode(p7, pkey, NULL, cert))) {
 549                 PKCS7error(PKCS7_R_DECRYPT_ERROR);
 550                 return 0;
 551         }
 552
 553         if (flags & PKCS7_TEXT) {
 554                 BIO *tmpbuf;
 555
 556                 /* Encrypt BIOs can't do BIO_gets() so add a buffer BIO */
 557                 if (!(tmpbuf = BIO_new(BIO_f_buffer()))) {
 558                         PKCS7error(ERR_R_MALLOC_FAILURE);
 559                         BIO_free_all(tmpmem);
 560                         return 0;
 561                 }
 562                 BIO_push(tmpbuf, tmpmem);
 563                 ret = SMIME_text(tmpbuf, data);
 564                 if (ret > 0 && BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
 565                         if (!BIO_get_cipher_status(tmpmem))
 566                                 ret = 0;
 567                 }
 568                 BIO_free_all(tmpbuf);
 569                 return ret;
 570         } else {
 571                 for (;;) {
 572                         i = BIO_read(tmpmem, buf, sizeof(buf));
 573                         if (i <= 0) {
 574                                 ret = 1;
 575                                 if (BIO_method_type(tmpmem) ==
 576                                     BIO_TYPE_CIPHER) {
 577                                         if (!BIO_get_cipher_status(tmpmem))
 578                                                 ret = 0;
 579                                 }
 580                                 break;
 581                         }
 582                         if (BIO_write(data, buf, i) != i) {
 583                                 ret = 0;
 584                                 break;
 585                         }
 586                 }
 587                 BIO_free_all(tmpmem);
 588                 return ret;
 589         }
 590 }