crypto/pkcs7/pk7_smime.c

   1 /*
   2  * Copyright 1999-2021 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_ex(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs,
  24                      BIO *data, int flags, OSSL_LIB_CTX *libctx,
  25                      const char *propq)
  26 {
  27     PKCS7 *p7;
  28     int i;
  29
  30     if ((p7 = PKCS7_new_ex(libctx, propq)) == NULL) {
  31         ERR_raise(ERR_LIB_PKCS7, 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         ERR_raise(ERR_LIB_PKCS7, 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_ex(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         ERR_raise(ERR_LIB_PKCS7, 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         ERR_raise(ERR_LIB_PKCS7, 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         ERR_raise(ERR_LIB_PKCS7,
 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         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_PKCS7_ADD_SIGNATURE_ERROR);
 131         return NULL;
 132     }
 133
 134     si->ctx = ossl_pkcs7_get0_ctx(p7);
 135     if (!(flags & PKCS7_NOCERTS)) {
 136         if (!PKCS7_add_certificate(p7, signcert))
 137             goto err;
 138     }
 139
 140     if (!(flags & PKCS7_NOATTR)) {
 141         if (!PKCS7_add_attrib_content_type(si, NULL))
 142             goto err;
 143         /* Add SMIMECapabilities */
 144         if (!(flags & PKCS7_NOSMIMECAP)) {
 145             if ((smcap = sk_X509_ALGOR_new_null()) == NULL) {
 146                 ERR_raise(ERR_LIB_PKCS7, ERR_R_MALLOC_FAILURE);
 147                 goto err;
 148             }
 149             if (!add_cipher_smcap(smcap, NID_aes_256_cbc, -1)
 150                 || !add_digest_smcap(smcap, NID_id_GostR3411_2012_256, -1)
 151                 || !add_digest_smcap(smcap, NID_id_GostR3411_2012_512, -1)
 152                 || !add_digest_smcap(smcap, NID_id_GostR3411_94, -1)
 153                 || !add_cipher_smcap(smcap, NID_id_Gost28147_89, -1)
 154                 || !add_cipher_smcap(smcap, NID_aes_192_cbc, -1)
 155                 || !add_cipher_smcap(smcap, NID_aes_128_cbc, -1)
 156                 || !add_cipher_smcap(smcap, NID_des_ede3_cbc, -1)
 157                 || !add_cipher_smcap(smcap, NID_rc2_cbc, 128)
 158                 || !add_cipher_smcap(smcap, NID_rc2_cbc, 64)
 159                 || !add_cipher_smcap(smcap, NID_des_cbc, -1)
 160                 || !add_cipher_smcap(smcap, NID_rc2_cbc, 40)
 161                 || !PKCS7_add_attrib_smimecap(si, smcap))
 162                 goto err;
 163             sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
 164             smcap = NULL;
 165         }
 166         if (flags & PKCS7_REUSE_DIGEST) {
 167             if (!pkcs7_copy_existing_digest(p7, si))
 168                 goto err;
 169             if (!(flags & PKCS7_PARTIAL)
 170                 && !PKCS7_SIGNER_INFO_sign(si))
 171                 goto err;
 172         }
 173     }
 174     return si;
 175  err:
 176     sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
 177     return NULL;
 178 }
 179
 180 /*
 181  * Search for a digest matching SignerInfo digest type and if found copy
 182  * across.
 183  */
 184
 185 static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si)
 186 {
 187     int i;
 188     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 189     PKCS7_SIGNER_INFO *sitmp;
 190     ASN1_OCTET_STRING *osdig = NULL;
 191     sinfos = PKCS7_get_signer_info(p7);
 192     for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 193         sitmp = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 194         if (si == sitmp)
 195             break;
 196         if (sk_X509_ATTRIBUTE_num(sitmp->auth_attr) <= 0)
 197             continue;
 198         if (!OBJ_cmp(si->digest_alg->algorithm, sitmp->digest_alg->algorithm)) {
 199             osdig = PKCS7_digest_from_attributes(sitmp->auth_attr);
 200             break;
 201         }
 202
 203     }
 204
 205     if (osdig != NULL)
 206         return PKCS7_add1_attrib_digest(si, osdig->data, osdig->length);
 207
 208     ERR_raise(ERR_LIB_PKCS7, PKCS7_R_NO_MATCHING_DIGEST_TYPE_FOUND);
 209     return 0;
 210 }
 211
 212 int PKCS7_verify(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store,
 213                  BIO *indata, BIO *out, int flags)
 214 {
 215     STACK_OF(X509) *signers;
 216     X509 *signer;
 217     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 218     PKCS7_SIGNER_INFO *si;
 219     X509_STORE_CTX *cert_ctx = NULL;
 220     char *buf = NULL;
 221     int i, j = 0, k, ret = 0;
 222     BIO *p7bio = NULL;
 223     BIO *tmpin = NULL, *tmpout = NULL;
 224     const PKCS7_CTX *p7_ctx;
 225
 226     if (p7 == NULL) {
 227         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_INVALID_NULL_POINTER);
 228         return 0;
 229     }
 230
 231     if (!PKCS7_type_is_signed(p7)) {
 232         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_WRONG_CONTENT_TYPE);
 233         return 0;
 234     }
 235
 236     /* Check for no data and no content: no data to verify signature */
 237     if (PKCS7_get_detached(p7) && !indata) {
 238         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_NO_CONTENT);
 239         return 0;
 240     }
 241
 242     if (flags & PKCS7_NO_DUAL_CONTENT) {
 243         /*
 244          * This was originally "#if 0" because we thought that only old broken
 245          * Netscape did this.  It turns out that Authenticode uses this kind
 246          * of "extended" PKCS7 format, and things like UEFI secure boot and
 247          * tools like osslsigncode need it.  In Authenticode the verification
 248          * process is different, but the existing PKCs7 verification works.
 249          */
 250         if (!PKCS7_get_detached(p7) && indata) {
 251             ERR_raise(ERR_LIB_PKCS7, PKCS7_R_CONTENT_AND_DATA_PRESENT);
 252             return 0;
 253         }
 254     }
 255
 256     sinfos = PKCS7_get_signer_info(p7);
 257
 258     if (!sinfos || !sk_PKCS7_SIGNER_INFO_num(sinfos)) {
 259         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_NO_SIGNATURES_ON_DATA);
 260         return 0;
 261     }
 262
 263     signers = PKCS7_get0_signers(p7, certs, flags);
 264     if (signers == NULL)
 265         return 0;
 266
 267     /* Now verify the certificates */
 268     p7_ctx = ossl_pkcs7_get0_ctx(p7);
 269     cert_ctx = X509_STORE_CTX_new_ex(ossl_pkcs7_ctx_get0_libctx(p7_ctx),
 270                                      ossl_pkcs7_ctx_get0_propq(p7_ctx));
 271     if (cert_ctx == NULL)
 272         goto err;
 273     if (!(flags & PKCS7_NOVERIFY))
 274         for (k = 0; k < sk_X509_num(signers); k++) {
 275             signer = sk_X509_value(signers, k);
 276             if (!(flags & PKCS7_NOCHAIN)) {
 277                 if (!X509_STORE_CTX_init(cert_ctx, store, signer,
 278                                          p7->d.sign->cert)) {
 279                     ERR_raise(ERR_LIB_PKCS7, ERR_R_X509_LIB);
 280                     goto err;
 281                 }
 282                 X509_STORE_CTX_set_default(cert_ctx, "smime_sign");
 283             } else if (!X509_STORE_CTX_init(cert_ctx, store, signer, NULL)) {
 284                 ERR_raise(ERR_LIB_PKCS7, ERR_R_X509_LIB);
 285                 goto err;
 286             }
 287             if (!(flags & PKCS7_NOCRL))
 288                 X509_STORE_CTX_set0_crls(cert_ctx, p7->d.sign->crl);
 289             i = X509_verify_cert(cert_ctx);
 290             if (i <= 0)
 291                 j = X509_STORE_CTX_get_error(cert_ctx);
 292             if (i <= 0) {
 293                 ERR_raise_data(ERR_LIB_PKCS7, PKCS7_R_CERTIFICATE_VERIFY_ERROR,
 294                                "Verify error: %s",
 295                                X509_verify_cert_error_string(j));
 296                 goto err;
 297             }
 298             /* Check for revocation status here */
 299         }
 300
 301     /*
 302      * Performance optimization: if the content is a memory BIO then store
 303      * its contents in a temporary read only memory BIO. This avoids
 304      * potentially large numbers of slow copies of data which will occur when
 305      * reading from a read write memory BIO when signatures are calculated.
 306      */
 307
 308     if (indata && (BIO_method_type(indata) == BIO_TYPE_MEM)) {
 309         char *ptr;
 310         long len;
 311         len = BIO_get_mem_data(indata, &ptr);
 312         tmpin = (len == 0) ? indata : BIO_new_mem_buf(ptr, len);
 313         if (tmpin == NULL) {
 314             ERR_raise(ERR_LIB_PKCS7, ERR_R_MALLOC_FAILURE);
 315             goto err;
 316         }
 317     } else
 318         tmpin = indata;
 319
 320     if ((p7bio = PKCS7_dataInit(p7, tmpin)) == NULL)
 321         goto err;
 322
 323     if (flags & PKCS7_TEXT) {
 324         if ((tmpout = BIO_new(BIO_s_mem())) == NULL) {
 325             ERR_raise(ERR_LIB_PKCS7, ERR_R_MALLOC_FAILURE);
 326             goto err;
 327         }
 328         BIO_set_mem_eof_return(tmpout, 0);
 329     } else
 330         tmpout = out;
 331
 332     /* We now have to 'read' from p7bio to calculate digests etc. */
 333     if ((buf = OPENSSL_malloc(BUFFERSIZE)) == NULL) {
 334         ERR_raise(ERR_LIB_PKCS7, ERR_R_MALLOC_FAILURE);
 335         goto err;
 336     }
 337     for (;;) {
 338         i = BIO_read(p7bio, buf, BUFFERSIZE);
 339         if (i <= 0)
 340             break;
 341         if (tmpout)
 342             BIO_write(tmpout, buf, i);
 343     }
 344
 345     if (flags & PKCS7_TEXT) {
 346         if (!SMIME_text(tmpout, out)) {
 347             ERR_raise(ERR_LIB_PKCS7, PKCS7_R_SMIME_TEXT_ERROR);
 348             BIO_free(tmpout);
 349             goto err;
 350         }
 351         BIO_free(tmpout);
 352     }
 353
 354     /* Now Verify All Signatures */
 355     if (!(flags & PKCS7_NOSIGS))
 356         for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 357             si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 358             signer = sk_X509_value(signers, i);
 359             j = PKCS7_signatureVerify(p7bio, p7, si, signer);
 360             if (j <= 0) {
 361                 ERR_raise(ERR_LIB_PKCS7, PKCS7_R_SIGNATURE_FAILURE);
 362                 goto err;
 363             }
 364         }
 365
 366     ret = 1;
 367
 368  err:
 369     X509_STORE_CTX_free(cert_ctx);
 370     OPENSSL_free(buf);
 371     if (tmpin == indata) {
 372         if (indata)
 373             BIO_pop(p7bio);
 374     }
 375     BIO_free_all(p7bio);
 376     sk_X509_free(signers);
 377     return ret;
 378 }
 379
 380 STACK_OF(X509) *PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs,
 381                                    int flags)
 382 {
 383     STACK_OF(X509) *signers;
 384     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 385     PKCS7_SIGNER_INFO *si;
 386     PKCS7_ISSUER_AND_SERIAL *ias;
 387     X509 *signer;
 388     int i;
 389
 390     if (p7 == NULL) {
 391         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_INVALID_NULL_POINTER);
 392         return NULL;
 393     }
 394
 395     if (!PKCS7_type_is_signed(p7)) {
 396         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_WRONG_CONTENT_TYPE);
 397         return NULL;
 398     }
 399
 400     /* Collect all the signers together */
 401
 402     sinfos = PKCS7_get_signer_info(p7);
 403
 404     if (sk_PKCS7_SIGNER_INFO_num(sinfos) <= 0) {
 405         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_NO_SIGNERS);
 406         return 0;
 407     }
 408
 409     if ((signers = sk_X509_new_null()) == NULL) {
 410         ERR_raise(ERR_LIB_PKCS7, ERR_R_MALLOC_FAILURE);
 411         return NULL;
 412     }
 413
 414     for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 415         si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 416         ias = si->issuer_and_serial;
 417         signer = NULL;
 418         /* If any certificates passed they take priority */
 419         if (certs)
 420             signer = X509_find_by_issuer_and_serial(certs,
 421                                                     ias->issuer, ias->serial);
 422         if (!signer && !(flags & PKCS7_NOINTERN)
 423             && p7->d.sign->cert)
 424             signer =
 425                 X509_find_by_issuer_and_serial(p7->d.sign->cert,
 426                                                ias->issuer, ias->serial);
 427         if (!signer) {
 428             ERR_raise(ERR_LIB_PKCS7, PKCS7_R_SIGNER_CERTIFICATE_NOT_FOUND);
 429             sk_X509_free(signers);
 430             return 0;
 431         }
 432
 433         if (!sk_X509_push(signers, signer)) {
 434             sk_X509_free(signers);
 435             return NULL;
 436         }
 437     }
 438     return signers;
 439 }
 440
 441 /* Build a complete PKCS#7 enveloped data */
 442
 443 PKCS7 *PKCS7_encrypt_ex(STACK_OF(X509) *certs, BIO *in,
 444                         const EVP_CIPHER *cipher, int flags,
 445                         OSSL_LIB_CTX *libctx, const char *propq)
 446 {
 447     PKCS7 *p7;
 448     BIO *p7bio = NULL;
 449     int i;
 450     X509 *x509;
 451
 452     if ((p7 = PKCS7_new_ex(libctx, propq)) == NULL) {
 453         ERR_raise(ERR_LIB_PKCS7, ERR_R_MALLOC_FAILURE);
 454         return NULL;
 455     }
 456
 457     if (!PKCS7_set_type(p7, NID_pkcs7_enveloped))
 458         goto err;
 459     if (!PKCS7_set_cipher(p7, cipher)) {
 460         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_ERROR_SETTING_CIPHER);
 461         goto err;
 462     }
 463
 464     for (i = 0; i < sk_X509_num(certs); i++) {
 465         x509 = sk_X509_value(certs, i);
 466         if (!PKCS7_add_recipient(p7, x509)) {
 467             ERR_raise(ERR_LIB_PKCS7, PKCS7_R_ERROR_ADDING_RECIPIENT);
 468             goto err;
 469         }
 470     }
 471
 472     if (flags & PKCS7_STREAM)
 473         return p7;
 474
 475     if (PKCS7_final(p7, in, flags))
 476         return p7;
 477
 478  err:
 479
 480     BIO_free_all(p7bio);
 481     PKCS7_free(p7);
 482     return NULL;
 483
 484 }
 485
 486 PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher,
 487                      int flags)
 488 {
 489     return PKCS7_encrypt_ex(certs, in, cipher, flags, NULL, NULL);
 490 }
 491
 492
 493 int PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags)
 494 {
 495     BIO *tmpmem;
 496     int ret = 0, i;
 497     char *buf = NULL;
 498
 499     if (p7 == NULL) {
 500         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_INVALID_NULL_POINTER);
 501         return 0;
 502     }
 503
 504     if (!PKCS7_type_is_enveloped(p7)) {
 505         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_WRONG_CONTENT_TYPE);
 506         return 0;
 507     }
 508
 509     if (cert && !X509_check_private_key(cert, pkey)) {
 510         ERR_raise(ERR_LIB_PKCS7,
 511                   PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
 512         return 0;
 513     }
 514
 515     if ((tmpmem = PKCS7_dataDecode(p7, pkey, NULL, cert)) == NULL) {
 516         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_DECRYPT_ERROR);
 517         return 0;
 518     }
 519
 520     if (flags & PKCS7_TEXT) {
 521         BIO *tmpbuf, *bread;
 522         /* Encrypt BIOs can't do BIO_gets() so add a buffer BIO */
 523         if ((tmpbuf = BIO_new(BIO_f_buffer())) == NULL) {
 524             ERR_raise(ERR_LIB_PKCS7, ERR_R_MALLOC_FAILURE);
 525             BIO_free_all(tmpmem);
 526             return 0;
 527         }
 528         if ((bread = BIO_push(tmpbuf, tmpmem)) == NULL) {
 529             ERR_raise(ERR_LIB_PKCS7, ERR_R_MALLOC_FAILURE);
 530             BIO_free_all(tmpbuf);
 531             BIO_free_all(tmpmem);
 532             return 0;
 533         }
 534         ret = SMIME_text(bread, data);
 535         if (ret > 0 && BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
 536             if (!BIO_get_cipher_status(tmpmem))
 537                 ret = 0;
 538         }
 539         BIO_free_all(bread);
 540         return ret;
 541     }
 542     if ((buf = OPENSSL_malloc(BUFFERSIZE)) == NULL) {
 543         ERR_raise(ERR_LIB_PKCS7, ERR_R_MALLOC_FAILURE);
 544         goto err;
 545     }
 546     for (;;) {
 547         i = BIO_read(tmpmem, buf, BUFFERSIZE);
 548         if (i <= 0) {
 549             ret = 1;
 550             if (BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
 551                 if (!BIO_get_cipher_status(tmpmem))
 552                     ret = 0;
 553             }
 554
 555             break;
 556         }
 557         if (BIO_write(data, buf, i) != i) {
 558             break;
 559         }
 560     }
 561 err:
 562     OPENSSL_free(buf);
 563     BIO_free_all(tmpmem);
 564     return ret;
 565 }