1 /* $OpenBSD: pk7_smime.c,v 1.27 2024/04/20 10:11:55 tb 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 #include "x509_local.h" 68 69 static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si); 70 71 PKCS7 * 72 PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs, BIO *data, 73 int flags) 74 { 75 PKCS7 *p7; 76 int i; 77 78 if (!(p7 = PKCS7_new())) { 79 PKCS7error(ERR_R_MALLOC_FAILURE); 80 return NULL; 81 } 82 83 if (!PKCS7_set_type(p7, NID_pkcs7_signed)) 84 goto err; 85 86 if (!PKCS7_content_new(p7, NID_pkcs7_data)) 87 goto err; 88 89 if (pkey && !PKCS7_sign_add_signer(p7, signcert, pkey, NULL, flags)) { 90 PKCS7error(PKCS7_R_PKCS7_ADD_SIGNER_ERROR); 91 goto err; 92 } 93 94 if (!(flags & PKCS7_NOCERTS)) { 95 for (i = 0; i < sk_X509_num(certs); i++) { 96 if (!PKCS7_add_certificate(p7, sk_X509_value(certs, i))) 97 goto err; 98 } 99 } 100 101 if (flags & PKCS7_DETACHED) 102 PKCS7_set_detached(p7, 1); 103 104 if (flags & (PKCS7_STREAM|PKCS7_PARTIAL)) 105 return p7; 106 107 if (PKCS7_final(p7, data, flags)) 108 return p7; 109 110 err: 111 PKCS7_free(p7); 112 return NULL; 113 } 114 LCRYPTO_ALIAS(PKCS7_sign); 115 116 int 117 PKCS7_final(PKCS7 *p7, BIO *data, int flags) 118 { 119 BIO *p7bio; 120 int ret = 0; 121 122 if (!(p7bio = PKCS7_dataInit(p7, NULL))) { 123 PKCS7error(ERR_R_MALLOC_FAILURE); 124 return 0; 125 } 126 127 SMIME_crlf_copy(data, p7bio, flags); 128 129 (void)BIO_flush(p7bio); 130 131 if (!PKCS7_dataFinal(p7, p7bio)) { 132 PKCS7error(PKCS7_R_PKCS7_DATASIGN); 133 goto err; 134 } 135 136 ret = 1; 137 138 err: 139 BIO_free_all(p7bio); 140 141 return ret; 142 } 143 LCRYPTO_ALIAS(PKCS7_final); 144 145 /* Check to see if a cipher exists and if so add S/MIME capabilities */ 146 147 static int 148 add_cipher_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg) 149 { 150 if (EVP_get_cipherbynid(nid)) 151 return PKCS7_simple_smimecap(sk, nid, arg); 152 return 1; 153 } 154 155 PKCS7_SIGNER_INFO * 156 PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert, EVP_PKEY *pkey, 157 const EVP_MD *md, int flags) 158 { 159 PKCS7_SIGNER_INFO *si = NULL; 160 STACK_OF(X509_ALGOR) *smcap = NULL; 161 162 if (!X509_check_private_key(signcert, pkey)) { 163 PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE); 164 return NULL; 165 } 166 167 if (!(si = PKCS7_add_signature(p7, signcert, pkey, md))) { 168 PKCS7error(PKCS7_R_PKCS7_ADD_SIGNATURE_ERROR); 169 return NULL; 170 } 171 172 if (!(flags & PKCS7_NOCERTS)) { 173 if (!PKCS7_add_certificate(p7, signcert)) 174 goto err; 175 } 176 177 if (!(flags & PKCS7_NOATTR)) { 178 if (!PKCS7_add_attrib_content_type(si, NULL)) 179 goto err; 180 /* Add SMIMECapabilities */ 181 if (!(flags & PKCS7_NOSMIMECAP)) { 182 if (!(smcap = sk_X509_ALGOR_new_null())) { 183 PKCS7error(ERR_R_MALLOC_FAILURE); 184 goto err; 185 } 186 if (!add_cipher_smcap(smcap, NID_aes_256_cbc, -1) || 187 !add_cipher_smcap(smcap, NID_aes_192_cbc, -1) || 188 !add_cipher_smcap(smcap, NID_aes_128_cbc, -1) || 189 !add_cipher_smcap(smcap, NID_des_ede3_cbc, -1) || 190 !add_cipher_smcap(smcap, NID_rc2_cbc, 128) || 191 !add_cipher_smcap(smcap, NID_rc2_cbc, 64) || 192 !add_cipher_smcap(smcap, NID_des_cbc, -1) || 193 !add_cipher_smcap(smcap, NID_rc2_cbc, 40) || 194 !PKCS7_add_attrib_smimecap(si, smcap)) 195 goto err; 196 sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free); 197 smcap = NULL; 198 } 199 if (flags & PKCS7_REUSE_DIGEST) { 200 if (!pkcs7_copy_existing_digest(p7, si)) 201 goto err; 202 if (!(flags & PKCS7_PARTIAL) && 203 !PKCS7_SIGNER_INFO_sign(si)) 204 goto err; 205 } 206 } 207 return si; 208 209 err: 210 if (smcap) 211 sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free); 212 return NULL; 213 } 214 LCRYPTO_ALIAS(PKCS7_sign_add_signer); 215 216 /* Search for a digest matching SignerInfo digest type and if found 217 * copy across. 218 */ 219 220 static int 221 pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si) 222 { 223 int i; 224 STACK_OF(PKCS7_SIGNER_INFO) *sinfos; 225 PKCS7_SIGNER_INFO *sitmp; 226 ASN1_OCTET_STRING *osdig = NULL; 227 228 sinfos = PKCS7_get_signer_info(p7); 229 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) { 230 sitmp = sk_PKCS7_SIGNER_INFO_value(sinfos, i); 231 if (si == sitmp) 232 break; 233 if (sk_X509_ATTRIBUTE_num(sitmp->auth_attr) <= 0) 234 continue; 235 if (!OBJ_cmp(si->digest_alg->algorithm, 236 sitmp->digest_alg->algorithm)) { 237 osdig = PKCS7_digest_from_attributes(sitmp->auth_attr); 238 break; 239 } 240 241 } 242 243 if (osdig) 244 return PKCS7_add1_attrib_digest(si, osdig->data, osdig->length); 245 246 PKCS7error(PKCS7_R_NO_MATCHING_DIGEST_TYPE_FOUND); 247 return 0; 248 } 249 250 int 251 PKCS7_verify(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store, BIO *indata, 252 BIO *out, int flags) 253 { 254 STACK_OF(X509) *signers; 255 X509 *signer; 256 STACK_OF(PKCS7_SIGNER_INFO) *sinfos; 257 PKCS7_SIGNER_INFO *si; 258 X509_STORE_CTX cert_ctx; 259 char buf[4096]; 260 int i, j = 0, k, ret = 0; 261 BIO *p7bio; 262 BIO *tmpin, *tmpout; 263 264 if (!p7) { 265 PKCS7error(PKCS7_R_INVALID_NULL_POINTER); 266 return 0; 267 } 268 269 if (!PKCS7_type_is_signed(p7)) { 270 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE); 271 return 0; 272 } 273 274 /* Check for no data and no content: no data to verify signature */ 275 if (PKCS7_get_detached(p7) && !indata) { 276 PKCS7error(PKCS7_R_NO_CONTENT); 277 return 0; 278 } 279 280 /* 281 * Very old Netscape illegally included empty content with 282 * a detached signature. Very old users should upgrade. 283 */ 284 /* Check for data and content: two sets of data */ 285 if (!PKCS7_get_detached(p7) && indata) { 286 PKCS7error(PKCS7_R_CONTENT_AND_DATA_PRESENT); 287 return 0; 288 } 289 290 sinfos = PKCS7_get_signer_info(p7); 291 292 if (!sinfos || !sk_PKCS7_SIGNER_INFO_num(sinfos)) { 293 PKCS7error(PKCS7_R_NO_SIGNATURES_ON_DATA); 294 return 0; 295 } 296 297 298 signers = PKCS7_get0_signers(p7, certs, flags); 299 300 if (!signers) 301 return 0; 302 303 /* Now verify the certificates */ 304 305 if (!(flags & PKCS7_NOVERIFY)) 306 for (k = 0; k < sk_X509_num(signers); k++) { 307 signer = sk_X509_value (signers, k); 308 if (!(flags & PKCS7_NOCHAIN)) { 309 if (!X509_STORE_CTX_init(&cert_ctx, store, 310 signer, p7->d.sign->cert)) { 311 PKCS7error(ERR_R_X509_LIB); 312 sk_X509_free(signers); 313 return 0; 314 } 315 if (X509_STORE_CTX_set_default(&cert_ctx, 316 "smime_sign") == 0) { 317 sk_X509_free(signers); 318 return 0; 319 } 320 } else if (!X509_STORE_CTX_init(&cert_ctx, store, 321 signer, NULL)) { 322 PKCS7error(ERR_R_X509_LIB); 323 sk_X509_free(signers); 324 return 0; 325 } 326 if (!(flags & PKCS7_NOCRL)) 327 X509_STORE_CTX_set0_crls(&cert_ctx, p7->d.sign->crl); 328 i = X509_verify_cert(&cert_ctx); 329 if (i <= 0) 330 j = X509_STORE_CTX_get_error(&cert_ctx); 331 X509_STORE_CTX_cleanup(&cert_ctx); 332 if (i <= 0) { 333 PKCS7error(PKCS7_R_CERTIFICATE_VERIFY_ERROR); 334 ERR_asprintf_error_data("Verify error:%s", 335 X509_verify_cert_error_string(j)); 336 sk_X509_free(signers); 337 return 0; 338 } 339 /* Check for revocation status here */ 340 } 341 342 /* 343 * Performance optimization: if the content is a memory BIO then 344 * store its contents in a temporary read only memory BIO. This 345 * avoids potentially large numbers of slow copies of data which will 346 * occur when reading from a read write memory BIO when signatures 347 * are calculated. 348 */ 349 if (indata && (BIO_method_type(indata) == BIO_TYPE_MEM)) { 350 char *ptr; 351 long len; 352 353 len = BIO_get_mem_data(indata, &ptr); 354 tmpin = BIO_new_mem_buf(ptr, len); 355 if (tmpin == NULL) { 356 PKCS7error(ERR_R_MALLOC_FAILURE); 357 return 0; 358 } 359 } else 360 tmpin = indata; 361 362 363 if (!(p7bio = PKCS7_dataInit(p7, tmpin))) 364 goto err; 365 366 if (flags & PKCS7_TEXT) { 367 if (!(tmpout = BIO_new(BIO_s_mem()))) { 368 PKCS7error(ERR_R_MALLOC_FAILURE); 369 goto err; 370 } 371 BIO_set_mem_eof_return(tmpout, 0); 372 } else 373 tmpout = out; 374 375 /* We now have to 'read' from p7bio to calculate digests etc. */ 376 for (;;) { 377 i = BIO_read(p7bio, buf, sizeof(buf)); 378 if (i <= 0) 379 break; 380 if (tmpout) 381 BIO_write(tmpout, buf, i); 382 } 383 384 if (flags & PKCS7_TEXT) { 385 if (!SMIME_text(tmpout, out)) { 386 PKCS7error(PKCS7_R_SMIME_TEXT_ERROR); 387 BIO_free(tmpout); 388 goto err; 389 } 390 BIO_free(tmpout); 391 } 392 393 /* Now Verify All Signatures */ 394 if (!(flags & PKCS7_NOSIGS)) 395 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) { 396 si = sk_PKCS7_SIGNER_INFO_value(sinfos, i); 397 signer = sk_X509_value (signers, i); 398 j = PKCS7_signatureVerify(p7bio, p7, si, signer); 399 if (j <= 0) { 400 PKCS7error(PKCS7_R_SIGNATURE_FAILURE); 401 goto err; 402 } 403 } 404 405 ret = 1; 406 407 err: 408 if (tmpin == indata) { 409 if (indata) 410 BIO_pop(p7bio); 411 } 412 BIO_free_all(p7bio); 413 sk_X509_free(signers); 414 415 return ret; 416 } 417 LCRYPTO_ALIAS(PKCS7_verify); 418 419 STACK_OF(X509) * 420 PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs, int flags) 421 { 422 STACK_OF(X509) *signers; 423 STACK_OF(PKCS7_SIGNER_INFO) *sinfos; 424 PKCS7_SIGNER_INFO *si; 425 PKCS7_ISSUER_AND_SERIAL *ias; 426 X509 *signer; 427 int i; 428 429 if (!p7) { 430 PKCS7error(PKCS7_R_INVALID_NULL_POINTER); 431 return NULL; 432 } 433 434 if (!PKCS7_type_is_signed(p7)) { 435 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE); 436 return NULL; 437 } 438 439 /* Collect all the signers together */ 440 sinfos = PKCS7_get_signer_info(p7); 441 if (sk_PKCS7_SIGNER_INFO_num(sinfos) <= 0) { 442 PKCS7error(PKCS7_R_NO_SIGNERS); 443 return 0; 444 } 445 446 if (!(signers = sk_X509_new_null())) { 447 PKCS7error(ERR_R_MALLOC_FAILURE); 448 return NULL; 449 } 450 451 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) { 452 si = sk_PKCS7_SIGNER_INFO_value(sinfos, i); 453 ias = si->issuer_and_serial; 454 signer = NULL; 455 /* If any certificates passed they take priority */ 456 if (certs) 457 signer = X509_find_by_issuer_and_serial (certs, 458 ias->issuer, ias->serial); 459 if (!signer && !(flags & PKCS7_NOINTERN) && p7->d.sign->cert) 460 signer = 461 X509_find_by_issuer_and_serial(p7->d.sign->cert, 462 ias->issuer, ias->serial); 463 if (!signer) { 464 PKCS7error(PKCS7_R_SIGNER_CERTIFICATE_NOT_FOUND); 465 sk_X509_free(signers); 466 return 0; 467 } 468 469 if (!sk_X509_push(signers, signer)) { 470 sk_X509_free(signers); 471 return NULL; 472 } 473 } 474 return signers; 475 } 476 LCRYPTO_ALIAS(PKCS7_get0_signers); 477 478 /* Build a complete PKCS#7 enveloped data */ 479 480 PKCS7 * 481 PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher, 482 int flags) 483 { 484 PKCS7 *p7; 485 BIO *p7bio = NULL; 486 int i; 487 X509 *x509; 488 489 if (!(p7 = PKCS7_new())) { 490 PKCS7error(ERR_R_MALLOC_FAILURE); 491 return NULL; 492 } 493 494 if (!PKCS7_set_type(p7, NID_pkcs7_enveloped)) 495 goto err; 496 if (!PKCS7_set_cipher(p7, cipher)) { 497 PKCS7error(PKCS7_R_ERROR_SETTING_CIPHER); 498 goto err; 499 } 500 501 for (i = 0; i < sk_X509_num(certs); i++) { 502 x509 = sk_X509_value(certs, i); 503 if (!PKCS7_add_recipient(p7, x509)) { 504 PKCS7error(PKCS7_R_ERROR_ADDING_RECIPIENT); 505 goto err; 506 } 507 } 508 509 if (flags & PKCS7_STREAM) 510 return p7; 511 512 if (PKCS7_final(p7, in, flags)) 513 return p7; 514 515 err: 516 BIO_free_all(p7bio); 517 PKCS7_free(p7); 518 return NULL; 519 } 520 LCRYPTO_ALIAS(PKCS7_encrypt); 521 522 int 523 PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags) 524 { 525 BIO *tmpmem; 526 int ret, i; 527 char buf[4096]; 528 529 if (!p7) { 530 PKCS7error(PKCS7_R_INVALID_NULL_POINTER); 531 return 0; 532 } 533 534 if (!PKCS7_type_is_enveloped(p7)) { 535 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE); 536 return 0; 537 } 538 539 if (cert && !X509_check_private_key(cert, pkey)) { 540 PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE); 541 return 0; 542 } 543 544 if (!(tmpmem = PKCS7_dataDecode(p7, pkey, NULL, cert))) { 545 PKCS7error(PKCS7_R_DECRYPT_ERROR); 546 return 0; 547 } 548 549 if (flags & PKCS7_TEXT) { 550 BIO *tmpbuf; 551 552 /* Encrypt BIOs can't do BIO_gets() so add a buffer BIO */ 553 if (!(tmpbuf = BIO_new(BIO_f_buffer()))) { 554 PKCS7error(ERR_R_MALLOC_FAILURE); 555 BIO_free_all(tmpmem); 556 return 0; 557 } 558 BIO_push(tmpbuf, tmpmem); 559 ret = SMIME_text(tmpbuf, data); 560 if (ret > 0 && BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) { 561 if (!BIO_get_cipher_status(tmpmem)) 562 ret = 0; 563 } 564 BIO_free_all(tmpbuf); 565 return ret; 566 } else { 567 for (;;) { 568 i = BIO_read(tmpmem, buf, sizeof(buf)); 569 if (i <= 0) { 570 ret = 1; 571 if (BIO_method_type(tmpmem) == 572 BIO_TYPE_CIPHER) { 573 if (!BIO_get_cipher_status(tmpmem)) 574 ret = 0; 575 } 576 break; 577 } 578 if (BIO_write(data, buf, i) != i) { 579 ret = 0; 580 break; 581 } 582 } 583 BIO_free_all(tmpmem); 584 return ret; 585 } 586 } 587 LCRYPTO_ALIAS(PKCS7_decrypt); 588