crypto/pkcs7/pk7_smime.c

   1 /*
   2  * Copyright 1999-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /* Simple PKCS#7 processing functions */
  11
  12 #include <stdio.h>
  13 #include "internal/cryptlib.h"
  14 #include <openssl/x509.h>
  15 #include <openssl/x509v3.h>
  16 #include "pk7_local.h"
  17
  18 #define BUFFERSIZE 4096
  19
  20
  21 static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si);
  22
  23 PKCS7 *PKCS7_sign_with_libctx(X509 *signcert, EVP_PKEY *pkey,
  24                               STACK_OF(X509) *certs, BIO *data, int flags,
  25                               OPENSSL_CTX *libctx, const char *propq)
  26 {
  27     PKCS7 *p7;
  28     int i;
  29
  30     if ((p7 = PKCS7_new_with_libctx(libctx, propq)) == NULL) {
  31         PKCS7err(0, ERR_R_MALLOC_FAILURE);
  32         return NULL;
  33     }
  34
  35     if (!PKCS7_set_type(p7, NID_pkcs7_signed))
  36         goto err;
  37
  38     if (!PKCS7_content_new(p7, NID_pkcs7_data))
  39         goto err;
  40
  41     if (pkey && !PKCS7_sign_add_signer(p7, signcert, pkey, NULL, flags)) {
  42         PKCS7err(0, PKCS7_R_PKCS7_ADD_SIGNER_ERROR);
  43         goto err;
  44     }
  45
  46     if (!(flags & PKCS7_NOCERTS)) {
  47         for (i = 0; i < sk_X509_num(certs); i++) {
  48             if (!PKCS7_add_certificate(p7, sk_X509_value(certs, i)))
  49                 goto err;
  50         }
  51     }
  52
  53     if (flags & PKCS7_DETACHED)
  54         PKCS7_set_detached(p7, 1);
  55
  56     if (flags & (PKCS7_STREAM | PKCS7_PARTIAL))
  57         return p7;
  58
  59     if (PKCS7_final(p7, data, flags))
  60         return p7;
  61
  62  err:
  63     PKCS7_free(p7);
  64     return NULL;
  65 }
  66
  67 PKCS7 *PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs,
  68                   BIO *data, int flags)
  69 {
  70     return PKCS7_sign_with_libctx(signcert, pkey, certs, data, flags, NULL, NULL);
  71 }
  72
  73
  74 int PKCS7_final(PKCS7 *p7, BIO *data, int flags)
  75 {
  76     BIO *p7bio;
  77     int ret = 0;
  78
  79     if ((p7bio = PKCS7_dataInit(p7, NULL)) == NULL) {
  80         PKCS7err(PKCS7_F_PKCS7_FINAL, ERR_R_MALLOC_FAILURE);
  81         return 0;
  82     }
  83
  84     SMIME_crlf_copy(data, p7bio, flags);
  85
  86     (void)BIO_flush(p7bio);
  87
  88     if (!PKCS7_dataFinal(p7, p7bio)) {
  89         PKCS7err(PKCS7_F_PKCS7_FINAL, PKCS7_R_PKCS7_DATASIGN);
  90         goto err;
  91     }
  92     ret = 1;
  93 err:
  94     BIO_free_all(p7bio);
  95
  96     return ret;
  97
  98 }
  99
 100 /* Check to see if a cipher exists and if so add S/MIME capabilities */
 101
 102 static int add_cipher_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
 103 {
 104     if (EVP_get_cipherbynid(nid))
 105         return PKCS7_simple_smimecap(sk, nid, arg);
 106     return 1;
 107 }
 108
 109 static int add_digest_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
 110 {
 111     if (EVP_get_digestbynid(nid))
 112         return PKCS7_simple_smimecap(sk, nid, arg);
 113     return 1;
 114 }
 115
 116 PKCS7_SIGNER_INFO *PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert,
 117                                          EVP_PKEY *pkey, const EVP_MD *md,
 118                                          int flags)
 119 {
 120     PKCS7_SIGNER_INFO *si = NULL;
 121     STACK_OF(X509_ALGOR) *smcap = NULL;
 122
 123     if (!X509_check_private_key(signcert, pkey)) {
 124         PKCS7err(PKCS7_F_PKCS7_SIGN_ADD_SIGNER,
 125                  PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
 126         return NULL;
 127     }
 128
 129     if ((si = PKCS7_add_signature(p7, signcert, pkey, md)) == NULL) {
 130         PKCS7err(PKCS7_F_PKCS7_SIGN_ADD_SIGNER,
 131                  PKCS7_R_PKCS7_ADD_SIGNATURE_ERROR);
 132         return NULL;
 133     }
 134
 135     si->ctx = pkcs7_get0_ctx(p7);
 136     if (!(flags & PKCS7_NOCERTS)) {
 137         if (!PKCS7_add_certificate(p7, signcert))
 138             goto err;
 139     }
 140
 141     if (!(flags & PKCS7_NOATTR)) {
 142         if (!PKCS7_add_attrib_content_type(si, NULL))
 143             goto err;
 144         /* Add SMIMECapabilities */
 145         if (!(flags & PKCS7_NOSMIMECAP)) {
 146             if ((smcap = sk_X509_ALGOR_new_null()) == NULL) {
 147                 PKCS7err(PKCS7_F_PKCS7_SIGN_ADD_SIGNER, ERR_R_MALLOC_FAILURE);
 148                 goto err;
 149             }
 150             if (!add_cipher_smcap(smcap, NID_aes_256_cbc, -1)
 151                 || !add_digest_smcap(smcap, NID_id_GostR3411_2012_256, -1)
 152                 || !add_digest_smcap(smcap, NID_id_GostR3411_2012_512, -1)
 153                 || !add_digest_smcap(smcap, NID_id_GostR3411_94, -1)
 154                 || !add_cipher_smcap(smcap, NID_id_Gost28147_89, -1)
 155                 || !add_cipher_smcap(smcap, NID_aes_192_cbc, -1)
 156                 || !add_cipher_smcap(smcap, NID_aes_128_cbc, -1)
 157                 || !add_cipher_smcap(smcap, NID_des_ede3_cbc, -1)
 158                 || !add_cipher_smcap(smcap, NID_rc2_cbc, 128)
 159                 || !add_cipher_smcap(smcap, NID_rc2_cbc, 64)
 160                 || !add_cipher_smcap(smcap, NID_des_cbc, -1)
 161                 || !add_cipher_smcap(smcap, NID_rc2_cbc, 40)
 162                 || !PKCS7_add_attrib_smimecap(si, smcap))
 163                 goto err;
 164             sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
 165             smcap = NULL;
 166         }
 167         if (flags & PKCS7_REUSE_DIGEST) {
 168             if (!pkcs7_copy_existing_digest(p7, si))
 169                 goto err;
 170             if (!(flags & PKCS7_PARTIAL)
 171                 && !PKCS7_SIGNER_INFO_sign(si))
 172                 goto err;
 173         }
 174     }
 175     return si;
 176  err:
 177     sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
 178     return NULL;
 179 }
 180
 181 /*
 182  * Search for a digest matching SignerInfo digest type and if found copy
 183  * across.
 184  */
 185
 186 static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si)
 187 {
 188     int i;
 189     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 190     PKCS7_SIGNER_INFO *sitmp;
 191     ASN1_OCTET_STRING *osdig = NULL;
 192     sinfos = PKCS7_get_signer_info(p7);
 193     for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 194         sitmp = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 195         if (si == sitmp)
 196             break;
 197         if (sk_X509_ATTRIBUTE_num(sitmp->auth_attr) <= 0)
 198             continue;
 199         if (!OBJ_cmp(si->digest_alg->algorithm, sitmp->digest_alg->algorithm)) {
 200             osdig = PKCS7_digest_from_attributes(sitmp->auth_attr);
 201             break;
 202         }
 203
 204     }
 205
 206     if (osdig != NULL)
 207         return PKCS7_add1_attrib_digest(si, osdig->data, osdig->length);
 208
 209     PKCS7err(PKCS7_F_PKCS7_COPY_EXISTING_DIGEST,
 210              PKCS7_R_NO_MATCHING_DIGEST_TYPE_FOUND);
 211     return 0;
 212 }
 213
 214 int PKCS7_verify(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store,
 215                  BIO *indata, BIO *out, int flags)
 216 {
 217     STACK_OF(X509) *signers;
 218     X509 *signer;
 219     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 220     PKCS7_SIGNER_INFO *si;
 221     X509_STORE_CTX *cert_ctx = NULL;
 222     char *buf = NULL;
 223     int i, j = 0, k, ret = 0;
 224     BIO *p7bio = NULL;
 225     BIO *tmpin = NULL, *tmpout = NULL;
 226     const PKCS7_CTX *p7_ctx;
 227
 228     if (p7 == NULL) {
 229         PKCS7err(0, PKCS7_R_INVALID_NULL_POINTER);
 230         return 0;
 231     }
 232
 233     if (!PKCS7_type_is_signed(p7)) {
 234         PKCS7err(0, PKCS7_R_WRONG_CONTENT_TYPE);
 235         return 0;
 236     }
 237
 238     /* Check for no data and no content: no data to verify signature */
 239     if (PKCS7_get_detached(p7) && !indata) {
 240         PKCS7err(0, PKCS7_R_NO_CONTENT);
 241         return 0;
 242     }
 243
 244     if (flags & PKCS7_NO_DUAL_CONTENT) {
 245         /*
 246          * This was originally "#if 0" because we thought that only old broken
 247          * Netscape did this.  It turns out that Authenticode uses this kind
 248          * of "extended" PKCS7 format, and things like UEFI secure boot and
 249          * tools like osslsigncode need it.  In Authenticode the verification
 250          * process is different, but the existing PKCs7 verification works.
 251          */
 252         if (!PKCS7_get_detached(p7) && indata) {
 253             PKCS7err(0, PKCS7_R_CONTENT_AND_DATA_PRESENT);
 254             return 0;
 255         }
 256     }
 257
 258     sinfos = PKCS7_get_signer_info(p7);
 259
 260     if (!sinfos || !sk_PKCS7_SIGNER_INFO_num(sinfos)) {
 261         PKCS7err(0, PKCS7_R_NO_SIGNATURES_ON_DATA);
 262         return 0;
 263     }
 264
 265     signers = PKCS7_get0_signers(p7, certs, flags);
 266     if (signers == NULL)
 267         return 0;
 268
 269     /* Now verify the certificates */
 270     p7_ctx = pkcs7_get0_ctx(p7);
 271     cert_ctx = X509_STORE_CTX_new_with_libctx(p7_ctx->libctx, p7_ctx->propq);
 272     if (cert_ctx == NULL)
 273         goto err;
 274     if (!(flags & PKCS7_NOVERIFY))
 275         for (k = 0; k < sk_X509_num(signers); k++) {
 276             signer = sk_X509_value(signers, k);
 277             if (!(flags & PKCS7_NOCHAIN)) {
 278                 if (!X509_STORE_CTX_init(cert_ctx, store, signer,
 279                                          p7->d.sign->cert)) {
 280                     PKCS7err(0, ERR_R_X509_LIB);
 281                     goto err;
 282                 }
 283                 X509_STORE_CTX_set_default(cert_ctx, "smime_sign");
 284             } else if (!X509_STORE_CTX_init(cert_ctx, store, signer, NULL)) {
 285                 PKCS7err(0, ERR_R_X509_LIB);
 286                 goto err;
 287             }
 288             if (!(flags & PKCS7_NOCRL))
 289                 X509_STORE_CTX_set0_crls(cert_ctx, p7->d.sign->crl);
 290             i = X509_verify_cert(cert_ctx);
 291             if (i <= 0)
 292                 j = X509_STORE_CTX_get_error(cert_ctx);
 293             X509_STORE_CTX_cleanup(cert_ctx);
 294             if (i <= 0) {
 295                 PKCS7err(0, PKCS7_R_CERTIFICATE_VERIFY_ERROR);
 296                 ERR_add_error_data(2, "Verify error:",
 297                                    X509_verify_cert_error_string(j));
 298                 goto err;
 299             }
 300             /* Check for revocation status here */
 301         }
 302
 303     /*
 304      * Performance optimization: if the content is a memory BIO then store
 305      * its contents in a temporary read only memory BIO. This avoids
 306      * potentially large numbers of slow copies of data which will occur when
 307      * reading from a read write memory BIO when signatures are calculated.
 308      */
 309
 310     if (indata && (BIO_method_type(indata) == BIO_TYPE_MEM)) {
 311         char *ptr;
 312         long len;
 313         len = BIO_get_mem_data(indata, &ptr);
 314         tmpin = BIO_new_mem_buf(ptr, len);
 315         if (tmpin == NULL) {
 316             PKCS7err(0, ERR_R_MALLOC_FAILURE);
 317             goto err;
 318         }
 319     } else
 320         tmpin = indata;
 321
 322     if ((p7bio = PKCS7_dataInit(p7, tmpin)) == NULL)
 323         goto err;
 324
 325     if (flags & PKCS7_TEXT) {
 326         if ((tmpout = BIO_new(BIO_s_mem())) == NULL) {
 327             PKCS7err(0, ERR_R_MALLOC_FAILURE);
 328             goto err;
 329         }
 330         BIO_set_mem_eof_return(tmpout, 0);
 331     } else
 332         tmpout = out;
 333
 334     /* We now have to 'read' from p7bio to calculate digests etc. */
 335     if ((buf = OPENSSL_malloc(BUFFERSIZE)) == NULL) {
 336         PKCS7err(0, ERR_R_MALLOC_FAILURE);
 337         goto err;
 338     }
 339     for (;;) {
 340         i = BIO_read(p7bio, buf, BUFFERSIZE);
 341         if (i <= 0)
 342             break;
 343         if (tmpout)
 344             BIO_write(tmpout, buf, i);
 345     }
 346
 347     if (flags & PKCS7_TEXT) {
 348         if (!SMIME_text(tmpout, out)) {
 349             PKCS7err(0, PKCS7_R_SMIME_TEXT_ERROR);
 350             BIO_free(tmpout);
 351             goto err;
 352         }
 353         BIO_free(tmpout);
 354     }
 355
 356     /* Now Verify All Signatures */
 357     if (!(flags & PKCS7_NOSIGS))
 358         for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 359             si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 360             signer = sk_X509_value(signers, i);
 361             j = PKCS7_signatureVerify(p7bio, p7, si, signer);
 362             if (j <= 0) {
 363                 PKCS7err(0, PKCS7_R_SIGNATURE_FAILURE);
 364                 goto err;
 365             }
 366         }
 367
 368     ret = 1;
 369
 370  err:
 371     X509_STORE_CTX_free(cert_ctx);
 372     OPENSSL_free(buf);
 373     if (tmpin == indata) {
 374         if (indata)
 375             BIO_pop(p7bio);
 376     }
 377     BIO_free_all(p7bio);
 378     sk_X509_free(signers);
 379     return ret;
 380 }
 381
 382 STACK_OF(X509) *PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs,
 383                                    int flags)
 384 {
 385     STACK_OF(X509) *signers;
 386     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 387     PKCS7_SIGNER_INFO *si;
 388     PKCS7_ISSUER_AND_SERIAL *ias;
 389     X509 *signer;
 390     int i;
 391
 392     if (p7 == NULL) {
 393         PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS, PKCS7_R_INVALID_NULL_POINTER);
 394         return NULL;
 395     }
 396
 397     if (!PKCS7_type_is_signed(p7)) {
 398         PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS, PKCS7_R_WRONG_CONTENT_TYPE);
 399         return NULL;
 400     }
 401
 402     /* Collect all the signers together */
 403
 404     sinfos = PKCS7_get_signer_info(p7);
 405
 406     if (sk_PKCS7_SIGNER_INFO_num(sinfos) <= 0) {
 407         PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS, PKCS7_R_NO_SIGNERS);
 408         return 0;
 409     }
 410
 411     if ((signers = sk_X509_new_null()) == NULL) {
 412         PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS, ERR_R_MALLOC_FAILURE);
 413         return NULL;
 414     }
 415
 416     for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 417         si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 418         ias = si->issuer_and_serial;
 419         signer = NULL;
 420         /* If any certificates passed they take priority */
 421         if (certs)
 422             signer = X509_find_by_issuer_and_serial(certs,
 423                                                     ias->issuer, ias->serial);
 424         if (!signer && !(flags & PKCS7_NOINTERN)
 425             && p7->d.sign->cert)
 426             signer =
 427                 X509_find_by_issuer_and_serial(p7->d.sign->cert,
 428                                                ias->issuer, ias->serial);
 429         if (!signer) {
 430             PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS,
 431                      PKCS7_R_SIGNER_CERTIFICATE_NOT_FOUND);
 432             sk_X509_free(signers);
 433             return 0;
 434         }
 435
 436         if (!sk_X509_push(signers, signer)) {
 437             sk_X509_free(signers);
 438             return NULL;
 439         }
 440     }
 441     return signers;
 442 }
 443
 444 /* Build a complete PKCS#7 enveloped data */
 445
 446 PKCS7 *PKCS7_encrypt_with_libctx(STACK_OF(X509) *certs, BIO *in,
 447                                  const EVP_CIPHER *cipher, int flags,
 448                                  OPENSSL_CTX *libctx, const char *propq)
 449 {
 450     PKCS7 *p7;
 451     BIO *p7bio = NULL;
 452     int i;
 453     X509 *x509;
 454
 455     if ((p7 = PKCS7_new_with_libctx(libctx, propq)) == NULL) {
 456         PKCS7err(0, ERR_R_MALLOC_FAILURE);
 457         return NULL;
 458     }
 459
 460     if (!PKCS7_set_type(p7, NID_pkcs7_enveloped))
 461         goto err;
 462     if (!PKCS7_set_cipher(p7, cipher)) {
 463         PKCS7err(0, PKCS7_R_ERROR_SETTING_CIPHER);
 464         goto err;
 465     }
 466
 467     for (i = 0; i < sk_X509_num(certs); i++) {
 468         x509 = sk_X509_value(certs, i);
 469         if (!PKCS7_add_recipient(p7, x509)) {
 470             PKCS7err(0, PKCS7_R_ERROR_ADDING_RECIPIENT);
 471             goto err;
 472         }
 473     }
 474
 475     if (flags & PKCS7_STREAM)
 476         return p7;
 477
 478     if (PKCS7_final(p7, in, flags))
 479         return p7;
 480
 481  err:
 482
 483     BIO_free_all(p7bio);
 484     PKCS7_free(p7);
 485     return NULL;
 486
 487 }
 488
 489 PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher,
 490                      int flags)
 491 {
 492     return PKCS7_encrypt_with_libctx(certs, in, cipher, flags, NULL, NULL);
 493 }
 494
 495
 496 int PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags)
 497 {
 498     BIO *tmpmem;
 499     int ret = 0, i;
 500     char *buf = NULL;
 501
 502     if (p7 == NULL) {
 503         PKCS7err(PKCS7_F_PKCS7_DECRYPT, PKCS7_R_INVALID_NULL_POINTER);
 504         return 0;
 505     }
 506
 507     if (!PKCS7_type_is_enveloped(p7)) {
 508         PKCS7err(PKCS7_F_PKCS7_DECRYPT, PKCS7_R_WRONG_CONTENT_TYPE);
 509         return 0;
 510     }
 511
 512     if (cert && !X509_check_private_key(cert, pkey)) {
 513         PKCS7err(PKCS7_F_PKCS7_DECRYPT,
 514                  PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
 515         return 0;
 516     }
 517
 518     if ((tmpmem = PKCS7_dataDecode(p7, pkey, NULL, cert)) == NULL) {
 519         PKCS7err(PKCS7_F_PKCS7_DECRYPT, PKCS7_R_DECRYPT_ERROR);
 520         return 0;
 521     }
 522
 523     if (flags & PKCS7_TEXT) {
 524         BIO *tmpbuf, *bread;
 525         /* Encrypt BIOs can't do BIO_gets() so add a buffer BIO */
 526         if ((tmpbuf = BIO_new(BIO_f_buffer())) == NULL) {
 527             PKCS7err(PKCS7_F_PKCS7_DECRYPT, ERR_R_MALLOC_FAILURE);
 528             BIO_free_all(tmpmem);
 529             return 0;
 530         }
 531         if ((bread = BIO_push(tmpbuf, tmpmem)) == NULL) {
 532             PKCS7err(PKCS7_F_PKCS7_DECRYPT, ERR_R_MALLOC_FAILURE);
 533             BIO_free_all(tmpbuf);
 534             BIO_free_all(tmpmem);
 535             return 0;
 536         }
 537         ret = SMIME_text(bread, data);
 538         if (ret > 0 && BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
 539             if (!BIO_get_cipher_status(tmpmem))
 540                 ret = 0;
 541         }
 542         BIO_free_all(bread);
 543         return ret;
 544     }
 545     if ((buf = OPENSSL_malloc(BUFFERSIZE)) == NULL) {
 546         PKCS7err(PKCS7_F_PKCS7_DECRYPT, ERR_R_MALLOC_FAILURE);
 547         goto err;
 548     }
 549     for (;;) {
 550         i = BIO_read(tmpmem, buf, BUFFERSIZE);
 551         if (i <= 0) {
 552             ret = 1;
 553             if (BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
 554                 if (!BIO_get_cipher_status(tmpmem))
 555                     ret = 0;
 556             }
 557
 558             break;
 559         }
 560         if (BIO_write(data, buf, i) != i) {
 561             break;
 562         }
 563     }
 564 err:
 565     OPENSSL_free(buf);
 566     BIO_free_all(tmpmem);
 567     return ret;
 568 }