crypto/pkcs7/pk7_smime.c

   1 /*
   2  * Copyright 1999-2023 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_PKCS7_LIB);
  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_PKCS7_LIB);
  81         return 0;
  82     }
  83
  84     if (!SMIME_crlf_copy(data, p7bio, flags))
  85         goto err;
  86
  87     (void)BIO_flush(p7bio);
  88
  89     if (!PKCS7_dataFinal(p7, p7bio)) {
  90         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_PKCS7_DATASIGN);
  91         goto err;
  92     }
  93     ret = 1;
  94 err:
  95     BIO_free_all(p7bio);
  96
  97     return ret;
  98
  99 }
 100
 101 /* Check to see if a cipher exists and if so add S/MIME capabilities */
 102
 103 static int add_cipher_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
 104 {
 105     if (EVP_get_cipherbynid(nid))
 106         return PKCS7_simple_smimecap(sk, nid, arg);
 107     return 1;
 108 }
 109
 110 static int add_digest_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
 111 {
 112     if (EVP_get_digestbynid(nid))
 113         return PKCS7_simple_smimecap(sk, nid, arg);
 114     return 1;
 115 }
 116
 117 PKCS7_SIGNER_INFO *PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert,
 118                                          EVP_PKEY *pkey, const EVP_MD *md,
 119                                          int flags)
 120 {
 121     PKCS7_SIGNER_INFO *si = NULL;
 122     STACK_OF(X509_ALGOR) *smcap = NULL;
 123
 124     if (!X509_check_private_key(signcert, pkey)) {
 125         ERR_raise(ERR_LIB_PKCS7,
 126                   PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
 127         return NULL;
 128     }
 129
 130     if ((si = PKCS7_add_signature(p7, signcert, pkey, md)) == NULL) {
 131         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_PKCS7_ADD_SIGNATURE_ERROR);
 132         return NULL;
 133     }
 134
 135     si->ctx = ossl_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                 ERR_raise(ERR_LIB_PKCS7, ERR_R_CRYPTO_LIB);
 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     ERR_raise(ERR_LIB_PKCS7, PKCS7_R_NO_MATCHING_DIGEST_TYPE_FOUND);
 210     return 0;
 211 }
 212
 213 /* This strongly overlaps with CMS_verify(), partly with PKCS7_dataVerify() */
 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 *tmpout = NULL;
 226     const PKCS7_CTX *p7_ctx;
 227
 228     if (p7 == NULL) {
 229         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_INVALID_NULL_POINTER);
 230         return 0;
 231     }
 232
 233     if (!PKCS7_type_is_signed(p7)) {
 234         ERR_raise(ERR_LIB_PKCS7, 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 == NULL) {
 240         ERR_raise(ERR_LIB_PKCS7, 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 != NULL) {
 253             ERR_raise(ERR_LIB_PKCS7, 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         ERR_raise(ERR_LIB_PKCS7, 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 = ossl_pkcs7_get0_ctx(p7);
 271     cert_ctx = X509_STORE_CTX_new_ex(ossl_pkcs7_ctx_get0_libctx(p7_ctx),
 272                                      ossl_pkcs7_ctx_get0_propq(p7_ctx));
 273     if (cert_ctx == NULL)
 274         goto err;
 275     if (!(flags & PKCS7_NOVERIFY))
 276         for (k = 0; k < sk_X509_num(signers); k++) {
 277             signer = sk_X509_value(signers, k);
 278             if (!(flags & PKCS7_NOCHAIN)) {
 279                 if (!X509_STORE_CTX_init(cert_ctx, store, signer,
 280                                          p7->d.sign->cert)) {
 281                     ERR_raise(ERR_LIB_PKCS7, ERR_R_X509_LIB);
 282                     goto err;
 283                 }
 284                 if (!X509_STORE_CTX_set_default(cert_ctx, "smime_sign"))
 285                     goto err;
 286             } else if (!X509_STORE_CTX_init(cert_ctx, store, signer, NULL)) {
 287                 ERR_raise(ERR_LIB_PKCS7, ERR_R_X509_LIB);
 288                 goto err;
 289             }
 290             if (!(flags & PKCS7_NOCRL))
 291                 X509_STORE_CTX_set0_crls(cert_ctx, p7->d.sign->crl);
 292             i = X509_verify_cert(cert_ctx);
 293             if (i <= 0)
 294                 j = X509_STORE_CTX_get_error(cert_ctx);
 295             if (i <= 0) {
 296                 ERR_raise_data(ERR_LIB_PKCS7, PKCS7_R_CERTIFICATE_VERIFY_ERROR,
 297                                "Verify error: %s",
 298                                X509_verify_cert_error_string(j));
 299                 goto err;
 300             }
 301             /* Check for revocation status here */
 302         }
 303
 304     if ((p7bio = PKCS7_dataInit(p7, indata)) == NULL)
 305         goto err;
 306
 307     if (flags & PKCS7_TEXT) {
 308         if ((tmpout = BIO_new(BIO_s_mem())) == NULL) {
 309             ERR_raise(ERR_LIB_PKCS7, ERR_R_BIO_LIB);
 310             goto err;
 311         }
 312         BIO_set_mem_eof_return(tmpout, 0);
 313     } else
 314         tmpout = out;
 315
 316     /* We now have to 'read' from p7bio to calculate digests etc. */
 317     if ((buf = OPENSSL_malloc(BUFFERSIZE)) == NULL)
 318         goto err;
 319     for (;;) {
 320         i = BIO_read(p7bio, buf, BUFFERSIZE);
 321         if (i <= 0)
 322             break;
 323         if (tmpout)
 324             BIO_write(tmpout, buf, i);
 325     }
 326
 327     if (flags & PKCS7_TEXT) {
 328         if (!SMIME_text(tmpout, out)) {
 329             ERR_raise(ERR_LIB_PKCS7, PKCS7_R_SMIME_TEXT_ERROR);
 330             BIO_free(tmpout);
 331             goto err;
 332         }
 333         BIO_free(tmpout);
 334     }
 335
 336     /* Now Verify All Signatures */
 337     if (!(flags & PKCS7_NOSIGS))
 338         for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 339             si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 340             signer = sk_X509_value(signers, i);
 341             j = PKCS7_signatureVerify(p7bio, p7, si, signer);
 342             if (j <= 0) {
 343                 ERR_raise(ERR_LIB_PKCS7, PKCS7_R_SIGNATURE_FAILURE);
 344                 goto err;
 345             }
 346         }
 347
 348     ret = 1;
 349
 350  err:
 351     X509_STORE_CTX_free(cert_ctx);
 352     OPENSSL_free(buf);
 353     if (indata != NULL)
 354         BIO_pop(p7bio);
 355     BIO_free_all(p7bio);
 356     sk_X509_free(signers);
 357     return ret;
 358 }
 359
 360 STACK_OF(X509) *PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs,
 361                                    int flags)
 362 {
 363     STACK_OF(X509) *signers;
 364     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
 365     PKCS7_SIGNER_INFO *si;
 366     PKCS7_ISSUER_AND_SERIAL *ias;
 367     X509 *signer;
 368     int i;
 369
 370     if (p7 == NULL) {
 371         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_INVALID_NULL_POINTER);
 372         return NULL;
 373     }
 374
 375     if (!PKCS7_type_is_signed(p7)) {
 376         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_WRONG_CONTENT_TYPE);
 377         return NULL;
 378     }
 379
 380     /* Collect all the signers together */
 381
 382     sinfos = PKCS7_get_signer_info(p7);
 383
 384     if (sk_PKCS7_SIGNER_INFO_num(sinfos) <= 0) {
 385         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_NO_SIGNERS);
 386         return 0;
 387     }
 388
 389     if ((signers = sk_X509_new_null()) == NULL) {
 390         ERR_raise(ERR_LIB_PKCS7, ERR_R_CRYPTO_LIB);
 391         return NULL;
 392     }
 393
 394     for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
 395         si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
 396         ias = si->issuer_and_serial;
 397         signer = NULL;
 398         /* If any certificates passed they take priority */
 399         if (certs != NULL)
 400             signer = X509_find_by_issuer_and_serial(certs,
 401                                                     ias->issuer, ias->serial);
 402         if (signer == NULL && !(flags & PKCS7_NOINTERN)
 403             && p7->d.sign->cert)
 404             signer =
 405                 X509_find_by_issuer_and_serial(p7->d.sign->cert,
 406                                                ias->issuer, ias->serial);
 407         if (signer == NULL) {
 408             ERR_raise(ERR_LIB_PKCS7, PKCS7_R_SIGNER_CERTIFICATE_NOT_FOUND);
 409             sk_X509_free(signers);
 410             return 0;
 411         }
 412
 413         if (!sk_X509_push(signers, signer)) {
 414             sk_X509_free(signers);
 415             return NULL;
 416         }
 417     }
 418     return signers;
 419 }
 420
 421 /* Build a complete PKCS#7 enveloped data */
 422
 423 PKCS7 *PKCS7_encrypt_ex(STACK_OF(X509) *certs, BIO *in,
 424                         const EVP_CIPHER *cipher, int flags,
 425                         OSSL_LIB_CTX *libctx, const char *propq)
 426 {
 427     PKCS7 *p7;
 428     BIO *p7bio = NULL;
 429     int i;
 430     X509 *x509;
 431
 432     if ((p7 = PKCS7_new_ex(libctx, propq)) == NULL) {
 433         ERR_raise(ERR_LIB_PKCS7, ERR_R_PKCS7_LIB);
 434         return NULL;
 435     }
 436
 437     if (!PKCS7_set_type(p7, NID_pkcs7_enveloped))
 438         goto err;
 439     if (!PKCS7_set_cipher(p7, cipher)) {
 440         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_ERROR_SETTING_CIPHER);
 441         goto err;
 442     }
 443
 444     for (i = 0; i < sk_X509_num(certs); i++) {
 445         x509 = sk_X509_value(certs, i);
 446         if (!PKCS7_add_recipient(p7, x509)) {
 447             ERR_raise(ERR_LIB_PKCS7, PKCS7_R_ERROR_ADDING_RECIPIENT);
 448             goto err;
 449         }
 450     }
 451
 452     if (flags & PKCS7_STREAM)
 453         return p7;
 454
 455     if (PKCS7_final(p7, in, flags))
 456         return p7;
 457
 458  err:
 459
 460     BIO_free_all(p7bio);
 461     PKCS7_free(p7);
 462     return NULL;
 463
 464 }
 465
 466 PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher,
 467                      int flags)
 468 {
 469     return PKCS7_encrypt_ex(certs, in, cipher, flags, NULL, NULL);
 470 }
 471
 472
 473 int PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags)
 474 {
 475     BIO *tmpmem;
 476     int ret = 0, i;
 477     char *buf = NULL;
 478
 479     if (p7 == NULL) {
 480         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_INVALID_NULL_POINTER);
 481         return 0;
 482     }
 483
 484     if (!PKCS7_type_is_enveloped(p7)
 485         && !PKCS7_type_is_signedAndEnveloped(p7)) {
 486         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_WRONG_CONTENT_TYPE);
 487         return 0;
 488     }
 489
 490     if (cert && !X509_check_private_key(cert, pkey)) {
 491         ERR_raise(ERR_LIB_PKCS7,
 492                   PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
 493         return 0;
 494     }
 495
 496     if ((tmpmem = PKCS7_dataDecode(p7, pkey, NULL, cert)) == NULL) {
 497         ERR_raise(ERR_LIB_PKCS7, PKCS7_R_DECRYPT_ERROR);
 498         return 0;
 499     }
 500
 501     if (flags & PKCS7_TEXT) {
 502         BIO *tmpbuf, *bread;
 503         /* Encrypt BIOs can't do BIO_gets() so add a buffer BIO */
 504         if ((tmpbuf = BIO_new(BIO_f_buffer())) == NULL) {
 505             ERR_raise(ERR_LIB_PKCS7, ERR_R_BIO_LIB);
 506             BIO_free_all(tmpmem);
 507             return 0;
 508         }
 509         if ((bread = BIO_push(tmpbuf, tmpmem)) == NULL) {
 510             ERR_raise(ERR_LIB_PKCS7, ERR_R_BIO_LIB);
 511             BIO_free_all(tmpbuf);
 512             BIO_free_all(tmpmem);
 513             return 0;
 514         }
 515         ret = SMIME_text(bread, data);
 516         if (ret > 0 && BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
 517             if (BIO_get_cipher_status(tmpmem) <= 0)
 518                 ret = 0;
 519         }
 520         BIO_free_all(bread);
 521         return ret;
 522     }
 523     if ((buf = OPENSSL_malloc(BUFFERSIZE)) == NULL)
 524         goto err;
 525     for (;;) {
 526         i = BIO_read(tmpmem, buf, BUFFERSIZE);
 527         if (i <= 0) {
 528             ret = 1;
 529             if (BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
 530                 if (BIO_get_cipher_status(tmpmem) <= 0)
 531                     ret = 0;
 532             }
 533
 534             break;
 535         }
 536         if (BIO_write(data, buf, i) != i) {
 537             break;
 538         }
 539     }
 540 err:
 541     OPENSSL_free(buf);
 542     BIO_free_all(tmpmem);
 543     return ret;
 544 }