apps/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 /* S/MIME utility function */
  11
  12 #include <stdio.h>
  13 #include <string.h>
  14 #include "apps.h"
  15 #include "progs.h"
  16 #include <openssl/crypto.h>
  17 #include <openssl/pem.h>
  18 #include <openssl/err.h>
  19 #include <openssl/x509_vfy.h>
  20 #include <openssl/x509v3.h>
  21
  22 static int save_certs(char *signerfile, STACK_OF(X509) *signers);
  23 static int smime_cb(int ok, X509_STORE_CTX *ctx);
  24
  25 #define SMIME_OP        0x10
  26 #define SMIME_IP        0x20
  27 #define SMIME_SIGNERS   0x40
  28 #define SMIME_ENCRYPT   (1 | SMIME_OP)
  29 #define SMIME_DECRYPT   (2 | SMIME_IP)
  30 #define SMIME_SIGN      (3 | SMIME_OP | SMIME_SIGNERS)
  31 #define SMIME_VERIFY    (4 | SMIME_IP)
  32 #define SMIME_PK7OUT    (5 | SMIME_IP | SMIME_OP)
  33 #define SMIME_RESIGN    (6 | SMIME_IP | SMIME_OP | SMIME_SIGNERS)
  34
  35 typedef enum OPTION_choice {
  36     OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
  37     OPT_ENCRYPT, OPT_DECRYPT, OPT_SIGN, OPT_RESIGN, OPT_VERIFY,
  38     OPT_PK7OUT, OPT_TEXT, OPT_NOINTERN, OPT_NOVERIFY, OPT_NOCHAIN,
  39     OPT_NOCERTS, OPT_NOATTR, OPT_NODETACH, OPT_NOSMIMECAP,
  40     OPT_BINARY, OPT_NOSIGS, OPT_STREAM, OPT_INDEF, OPT_NOINDEF,
  41     OPT_CRLFEOL, OPT_ENGINE, OPT_PASSIN,
  42     OPT_TO, OPT_FROM, OPT_SUBJECT, OPT_SIGNER, OPT_RECIP, OPT_MD,
  43     OPT_CIPHER, OPT_INKEY, OPT_KEYFORM, OPT_CERTFILE, OPT_CAFILE,
  44     OPT_CAPATH, OPT_CASTORE, OPT_NOCAFILE, OPT_NOCAPATH, OPT_NOCASTORE,
  45     OPT_R_ENUM, OPT_PROV_ENUM,
  46     OPT_V_ENUM,
  47     OPT_IN, OPT_INFORM, OPT_OUT,
  48     OPT_OUTFORM, OPT_CONTENT
  49 } OPTION_CHOICE;
  50
  51 const OPTIONS smime_options[] = {
  52     {OPT_HELP_STR, 1, '-', "Usage: %s [options] [cert...]\n"},
  53
  54     OPT_SECTION("General"),
  55     {"help", OPT_HELP, '-', "Display this summary"},
  56     {"in", OPT_IN, '<', "Input file"},
  57     {"inform", OPT_INFORM, 'c', "Input format SMIME (default), PEM or DER"},
  58     {"out", OPT_OUT, '>', "Output file"},
  59     {"outform", OPT_OUTFORM, 'c',
  60      "Output format SMIME (default), PEM or DER"},
  61     {"inkey", OPT_INKEY, 's',
  62      "Input private key (if not signer or recipient)"},
  63     {"keyform", OPT_KEYFORM, 'f', "Input private key format (PEM or ENGINE)"},
  64 #ifndef OPENSSL_NO_ENGINE
  65     {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
  66 #endif
  67     {"stream", OPT_STREAM, '-', "Enable CMS streaming" },
  68     {"indef", OPT_INDEF, '-', "Same as -stream" },
  69     {"noindef", OPT_NOINDEF, '-', "Disable CMS streaming"},
  70
  71     OPT_SECTION("Action"),
  72     {"encrypt", OPT_ENCRYPT, '-', "Encrypt message"},
  73     {"decrypt", OPT_DECRYPT, '-', "Decrypt encrypted message"},
  74     {"sign", OPT_SIGN, '-', "Sign message"},
  75     {"resign", OPT_RESIGN, '-', "Resign a signed message"},
  76     {"verify", OPT_VERIFY, '-', "Verify signed message"},
  77
  78     OPT_SECTION("Signing/Encryption"),
  79     {"passin", OPT_PASSIN, 's', "Input file pass phrase source"},
  80     {"md", OPT_MD, 's', "Digest algorithm to use when signing or resigning"},
  81     {"", OPT_CIPHER, '-', "Any supported cipher"},
  82     {"pk7out", OPT_PK7OUT, '-', "Output PKCS#7 structure"},
  83     {"nointern", OPT_NOINTERN, '-',
  84      "Don't search certificates in message for signer"},
  85     {"nodetach", OPT_NODETACH, '-', "Use opaque signing"},
  86     {"noattr", OPT_NOATTR, '-', "Don't include any signed attributes"},
  87     {"binary", OPT_BINARY, '-', "Don't translate message to text"},
  88     {"signer", OPT_SIGNER, 's', "Signer certificate file"},
  89     {"content", OPT_CONTENT, '<',
  90      "Supply or override content for detached signature"},
  91     {"nocerts", OPT_NOCERTS, '-',
  92      "Don't include signers certificate when signing"},
  93
  94     OPT_SECTION("Verification/Decryption"),
  95     {"nosigs", OPT_NOSIGS, '-', "Don't verify message signature"},
  96     {"noverify", OPT_NOVERIFY, '-', "Don't verify signers certificate"},
  97
  98     {"certfile", OPT_CERTFILE, '<', "Other certificates file"},
  99     {"recip", OPT_RECIP, '<', "Recipient certificate file for decryption"},
 100
 101     OPT_SECTION("Email"),
 102     {"to", OPT_TO, 's', "To address"},
 103     {"from", OPT_FROM, 's', "From address"},
 104     {"subject", OPT_SUBJECT, 's', "Subject"},
 105     {"text", OPT_TEXT, '-', "Include or delete text MIME headers"},
 106     {"nosmimecap", OPT_NOSMIMECAP, '-', "Omit the SMIMECapabilities attribute"},
 107
 108     OPT_SECTION("Certificate chain"),
 109     {"CApath", OPT_CAPATH, '/', "Trusted certificates directory"},
 110     {"CAfile", OPT_CAFILE, '<', "Trusted certificates file"},
 111     {"CAstore", OPT_CASTORE, ':', "Trusted certificates store URI"},
 112     {"no-CAfile", OPT_NOCAFILE, '-',
 113      "Do not load the default certificates file"},
 114     {"no-CApath", OPT_NOCAPATH, '-',
 115      "Do not load certificates from the default certificates directory"},
 116     {"no-CAstore", OPT_NOCASTORE, '-',
 117      "Do not load certificates from the default certificates store"},
 118     {"nochain", OPT_NOCHAIN, '-',
 119      "set PKCS7_NOCHAIN so certificates contained in the message are not used as untrusted CAs" },
 120     {"crlfeol", OPT_CRLFEOL, '-', "Use CRLF as EOL termination instead of CR only"},
 121
 122     OPT_R_OPTIONS,
 123     OPT_V_OPTIONS,
 124     OPT_PROV_OPTIONS,
 125
 126     OPT_PARAMETERS(),
 127     {"cert", 0, 0, "Recipient certs, used when encrypting"},
 128     {NULL}
 129 };
 130
 131 int smime_main(int argc, char **argv)
 132 {
 133     BIO *in = NULL, *out = NULL, *indata = NULL;
 134     EVP_PKEY *key = NULL;
 135     PKCS7 *p7 = NULL;
 136     STACK_OF(OPENSSL_STRING) *sksigners = NULL, *skkeys = NULL;
 137     STACK_OF(X509) *encerts = NULL, *other = NULL;
 138     X509 *cert = NULL, *recip = NULL, *signer = NULL;
 139     X509_STORE *store = NULL;
 140     X509_VERIFY_PARAM *vpm = NULL;
 141     const EVP_CIPHER *cipher = NULL;
 142     const EVP_MD *sign_md = NULL;
 143     const char *CAfile = NULL, *CApath = NULL, *CAstore = NULL, *prog = NULL;
 144     char *certfile = NULL, *keyfile = NULL, *contfile = NULL;
 145     char *infile = NULL, *outfile = NULL, *signerfile = NULL, *recipfile = NULL;
 146     char *passinarg = NULL, *passin = NULL, *to = NULL, *from = NULL, *subject = NULL;
 147     OPTION_CHOICE o;
 148     int noCApath = 0, noCAfile = 0, noCAstore = 0;
 149     int flags = PKCS7_DETACHED, operation = 0, ret = 0, indef = 0;
 150     int informat = FORMAT_SMIME, outformat = FORMAT_SMIME, keyform =
 151         FORMAT_PEM;
 152     int vpmtouched = 0, rv = 0;
 153     ENGINE *e = NULL;
 154     const char *mime_eol = "\n";
 155
 156     if ((vpm = X509_VERIFY_PARAM_new()) == NULL)
 157         return 1;
 158
 159     prog = opt_init(argc, argv, smime_options);
 160     while ((o = opt_next()) != OPT_EOF) {
 161         switch (o) {
 162         case OPT_EOF:
 163         case OPT_ERR:
 164  opthelp:
 165             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
 166             goto end;
 167         case OPT_HELP:
 168             opt_help(smime_options);
 169             ret = 0;
 170             goto end;
 171         case OPT_INFORM:
 172             if (!opt_format(opt_arg(), OPT_FMT_PDS, &informat))
 173                 goto opthelp;
 174             break;
 175         case OPT_IN:
 176             infile = opt_arg();
 177             break;
 178         case OPT_OUTFORM:
 179             if (!opt_format(opt_arg(), OPT_FMT_PDS, &outformat))
 180                 goto opthelp;
 181             break;
 182         case OPT_OUT:
 183             outfile = opt_arg();
 184             break;
 185         case OPT_ENCRYPT:
 186             operation = SMIME_ENCRYPT;
 187             break;
 188         case OPT_DECRYPT:
 189             operation = SMIME_DECRYPT;
 190             break;
 191         case OPT_SIGN:
 192             operation = SMIME_SIGN;
 193             break;
 194         case OPT_RESIGN:
 195             operation = SMIME_RESIGN;
 196             break;
 197         case OPT_VERIFY:
 198             operation = SMIME_VERIFY;
 199             break;
 200         case OPT_PK7OUT:
 201             operation = SMIME_PK7OUT;
 202             break;
 203         case OPT_TEXT:
 204             flags |= PKCS7_TEXT;
 205             break;
 206         case OPT_NOINTERN:
 207             flags |= PKCS7_NOINTERN;
 208             break;
 209         case OPT_NOVERIFY:
 210             flags |= PKCS7_NOVERIFY;
 211             break;
 212         case OPT_NOCHAIN:
 213             flags |= PKCS7_NOCHAIN;
 214             break;
 215         case OPT_NOCERTS:
 216             flags |= PKCS7_NOCERTS;
 217             break;
 218         case OPT_NOATTR:
 219             flags |= PKCS7_NOATTR;
 220             break;
 221         case OPT_NODETACH:
 222             flags &= ~PKCS7_DETACHED;
 223             break;
 224         case OPT_NOSMIMECAP:
 225             flags |= PKCS7_NOSMIMECAP;
 226             break;
 227         case OPT_BINARY:
 228             flags |= PKCS7_BINARY;
 229             break;
 230         case OPT_NOSIGS:
 231             flags |= PKCS7_NOSIGS;
 232             break;
 233         case OPT_STREAM:
 234         case OPT_INDEF:
 235             indef = 1;
 236             break;
 237         case OPT_NOINDEF:
 238             indef = 0;
 239             break;
 240         case OPT_CRLFEOL:
 241             flags |= PKCS7_CRLFEOL;
 242             mime_eol = "\r\n";
 243             break;
 244         case OPT_R_CASES:
 245             if (!opt_rand(o))
 246                 goto end;
 247             break;
 248         case OPT_PROV_CASES:
 249             if (!opt_provider(o))
 250                 goto end;
 251             break;
 252         case OPT_ENGINE:
 253             e = setup_engine(opt_arg(), 0);
 254             break;
 255         case OPT_PASSIN:
 256             passinarg = opt_arg();
 257             break;
 258         case OPT_TO:
 259             to = opt_arg();
 260             break;
 261         case OPT_FROM:
 262             from = opt_arg();
 263             break;
 264         case OPT_SUBJECT:
 265             subject = opt_arg();
 266             break;
 267         case OPT_SIGNER:
 268             /* If previous -signer argument add signer to list */
 269             if (signerfile != NULL) {
 270                 if (sksigners == NULL
 271                     && (sksigners = sk_OPENSSL_STRING_new_null()) == NULL)
 272                     goto end;
 273                 sk_OPENSSL_STRING_push(sksigners, signerfile);
 274                 if (keyfile == NULL)
 275                     keyfile = signerfile;
 276                 if (skkeys == NULL
 277                     && (skkeys = sk_OPENSSL_STRING_new_null()) == NULL)
 278                     goto end;
 279                 sk_OPENSSL_STRING_push(skkeys, keyfile);
 280                 keyfile = NULL;
 281             }
 282             signerfile = opt_arg();
 283             break;
 284         case OPT_RECIP:
 285             recipfile = opt_arg();
 286             break;
 287         case OPT_MD:
 288             if (!opt_md(opt_arg(), &sign_md))
 289                 goto opthelp;
 290             break;
 291         case OPT_CIPHER:
 292             if (!opt_cipher(opt_unknown(), &cipher))
 293                 goto opthelp;
 294             break;
 295         case OPT_INKEY:
 296             /* If previous -inkey argument add signer to list */
 297             if (keyfile != NULL) {
 298                 if (signerfile == NULL) {
 299                     BIO_printf(bio_err,
 300                                "%s: Must have -signer before -inkey\n", prog);
 301                     goto opthelp;
 302                 }
 303                 if (sksigners == NULL
 304                     && (sksigners = sk_OPENSSL_STRING_new_null()) == NULL)
 305                     goto end;
 306                 sk_OPENSSL_STRING_push(sksigners, signerfile);
 307                 signerfile = NULL;
 308                 if (skkeys == NULL
 309                     && (skkeys = sk_OPENSSL_STRING_new_null()) == NULL)
 310                     goto end;
 311                 sk_OPENSSL_STRING_push(skkeys, keyfile);
 312             }
 313             keyfile = opt_arg();
 314             break;
 315         case OPT_KEYFORM:
 316             if (!opt_format(opt_arg(), OPT_FMT_ANY, &keyform))
 317                 goto opthelp;
 318             break;
 319         case OPT_CERTFILE:
 320             certfile = opt_arg();
 321             break;
 322         case OPT_CAFILE:
 323             CAfile = opt_arg();
 324             break;
 325         case OPT_CAPATH:
 326             CApath = opt_arg();
 327             break;
 328         case OPT_CASTORE:
 329             CAstore = opt_arg();
 330             break;
 331         case OPT_NOCAFILE:
 332             noCAfile = 1;
 333             break;
 334         case OPT_NOCAPATH:
 335             noCApath = 1;
 336             break;
 337         case OPT_NOCASTORE:
 338             noCAstore = 1;
 339             break;
 340         case OPT_CONTENT:
 341             contfile = opt_arg();
 342             break;
 343         case OPT_V_CASES:
 344             if (!opt_verify(o, vpm))
 345                 goto opthelp;
 346             vpmtouched++;
 347             break;
 348         }
 349     }
 350     argc = opt_num_rest();
 351     argv = opt_rest();
 352
 353     if (!(operation & SMIME_SIGNERS) && (skkeys != NULL || sksigners != NULL)) {
 354         BIO_puts(bio_err, "Multiple signers or keys not allowed\n");
 355         goto opthelp;
 356     }
 357
 358     if (operation & SMIME_SIGNERS) {
 359         /* Check to see if any final signer needs to be appended */
 360         if (keyfile && !signerfile) {
 361             BIO_puts(bio_err, "Illegal -inkey without -signer\n");
 362             goto opthelp;
 363         }
 364         if (signerfile != NULL) {
 365             if (sksigners == NULL
 366                 && (sksigners = sk_OPENSSL_STRING_new_null()) == NULL)
 367                 goto end;
 368             sk_OPENSSL_STRING_push(sksigners, signerfile);
 369             if (!skkeys && (skkeys = sk_OPENSSL_STRING_new_null()) == NULL)
 370                 goto end;
 371             if (!keyfile)
 372                 keyfile = signerfile;
 373             sk_OPENSSL_STRING_push(skkeys, keyfile);
 374         }
 375         if (sksigners == NULL) {
 376             BIO_printf(bio_err, "No signer certificate specified\n");
 377             goto opthelp;
 378         }
 379         signerfile = NULL;
 380         keyfile = NULL;
 381     } else if (operation == SMIME_DECRYPT) {
 382         if (recipfile == NULL && keyfile == NULL) {
 383             BIO_printf(bio_err,
 384                        "No recipient certificate or key specified\n");
 385             goto opthelp;
 386         }
 387     } else if (operation == SMIME_ENCRYPT) {
 388         if (argc == 0) {
 389             BIO_printf(bio_err, "No recipient(s) certificate(s) specified\n");
 390             goto opthelp;
 391         }
 392     } else if (!operation) {
 393         goto opthelp;
 394     }
 395
 396     if (!app_passwd(passinarg, NULL, &passin, NULL)) {
 397         BIO_printf(bio_err, "Error getting password\n");
 398         goto end;
 399     }
 400
 401     ret = 2;
 402
 403     if (!(operation & SMIME_SIGNERS))
 404         flags &= ~PKCS7_DETACHED;
 405
 406     if (!(operation & SMIME_OP)) {
 407         if (flags & PKCS7_BINARY)
 408             outformat = FORMAT_BINARY;
 409     }
 410
 411     if (!(operation & SMIME_IP)) {
 412         if (flags & PKCS7_BINARY)
 413             informat = FORMAT_BINARY;
 414     }
 415
 416     if (operation == SMIME_ENCRYPT) {
 417         if (cipher == NULL) {
 418 #ifndef OPENSSL_NO_DES
 419             cipher = EVP_des_ede3_cbc();
 420 #else
 421             BIO_printf(bio_err, "No cipher selected\n");
 422             goto end;
 423 #endif
 424         }
 425         encerts = sk_X509_new_null();
 426         if (encerts == NULL)
 427             goto end;
 428         while (*argv != NULL) {
 429             cert = load_cert(*argv, FORMAT_PEM,
 430                              "recipient certificate file");
 431             if (cert == NULL)
 432                 goto end;
 433             sk_X509_push(encerts, cert);
 434             cert = NULL;
 435             argv++;
 436         }
 437     }
 438
 439     if (certfile != NULL) {
 440         if (!load_certs(certfile, &other, FORMAT_PEM, NULL,
 441                         "certificate file")) {
 442             ERR_print_errors(bio_err);
 443             goto end;
 444         }
 445     }
 446
 447     if (recipfile != NULL && (operation == SMIME_DECRYPT)) {
 448         if ((recip = load_cert(recipfile, FORMAT_PEM,
 449                                "recipient certificate file")) == NULL) {
 450             ERR_print_errors(bio_err);
 451             goto end;
 452         }
 453     }
 454
 455     if (operation == SMIME_DECRYPT) {
 456         if (keyfile == NULL)
 457             keyfile = recipfile;
 458     } else if (operation == SMIME_SIGN) {
 459         if (keyfile == NULL)
 460             keyfile = signerfile;
 461     } else {
 462         keyfile = NULL;
 463     }
 464
 465     if (keyfile != NULL) {
 466         key = load_key(keyfile, keyform, 0, passin, e, "signing key file");
 467         if (key == NULL)
 468             goto end;
 469     }
 470
 471     in = bio_open_default(infile, 'r', informat);
 472     if (in == NULL)
 473         goto end;
 474
 475     if (operation & SMIME_IP) {
 476         if (informat == FORMAT_SMIME) {
 477             p7 = SMIME_read_PKCS7(in, &indata);
 478         } else if (informat == FORMAT_PEM) {
 479             p7 = PEM_read_bio_PKCS7(in, NULL, NULL, NULL);
 480         } else if (informat == FORMAT_ASN1) {
 481             p7 = d2i_PKCS7_bio(in, NULL);
 482         } else {
 483             BIO_printf(bio_err, "Bad input format for PKCS#7 file\n");
 484             goto end;
 485         }
 486
 487         if (p7 == NULL) {
 488             BIO_printf(bio_err, "Error reading S/MIME message\n");
 489             goto end;
 490         }
 491         if (contfile != NULL) {
 492             BIO_free(indata);
 493             if ((indata = BIO_new_file(contfile, "rb")) == NULL) {
 494                 BIO_printf(bio_err, "Can't read content file %s\n", contfile);
 495                 goto end;
 496             }
 497         }
 498     }
 499
 500     out = bio_open_default(outfile, 'w', outformat);
 501     if (out == NULL)
 502         goto end;
 503
 504     if (operation == SMIME_VERIFY) {
 505         if ((store = setup_verify(CAfile, noCAfile, CApath, noCApath,
 506                                   CAstore, noCAstore)) == NULL)
 507             goto end;
 508         X509_STORE_set_verify_cb(store, smime_cb);
 509         if (vpmtouched)
 510             X509_STORE_set1_param(store, vpm);
 511     }
 512
 513     ret = 3;
 514
 515     if (operation == SMIME_ENCRYPT) {
 516         if (indef)
 517             flags |= PKCS7_STREAM;
 518         p7 = PKCS7_encrypt(encerts, in, cipher, flags);
 519     } else if (operation & SMIME_SIGNERS) {
 520         int i;
 521         /*
 522          * If detached data content we only enable streaming if S/MIME output
 523          * format.
 524          */
 525         if (operation == SMIME_SIGN) {
 526             if (flags & PKCS7_DETACHED) {
 527                 if (outformat == FORMAT_SMIME)
 528                     flags |= PKCS7_STREAM;
 529             } else if (indef) {
 530                 flags |= PKCS7_STREAM;
 531             }
 532             flags |= PKCS7_PARTIAL;
 533             p7 = PKCS7_sign(NULL, NULL, other, in, flags);
 534             if (p7 == NULL)
 535                 goto end;
 536             if (flags & PKCS7_NOCERTS) {
 537                 for (i = 0; i < sk_X509_num(other); i++) {
 538                     X509 *x = sk_X509_value(other, i);
 539                     PKCS7_add_certificate(p7, x);
 540                 }
 541             }
 542         } else {
 543             flags |= PKCS7_REUSE_DIGEST;
 544         }
 545         for (i = 0; i < sk_OPENSSL_STRING_num(sksigners); i++) {
 546             signerfile = sk_OPENSSL_STRING_value(sksigners, i);
 547             keyfile = sk_OPENSSL_STRING_value(skkeys, i);
 548             signer = load_cert(signerfile, FORMAT_PEM,
 549                                "signer certificate");
 550             if (signer == NULL)
 551                 goto end;
 552             key = load_key(keyfile, keyform, 0, passin, e, "signing key file");
 553             if (key == NULL)
 554                 goto end;
 555             if (!PKCS7_sign_add_signer(p7, signer, key, sign_md, flags))
 556                 goto end;
 557             X509_free(signer);
 558             signer = NULL;
 559             EVP_PKEY_free(key);
 560             key = NULL;
 561         }
 562         /* If not streaming or resigning finalize structure */
 563         if ((operation == SMIME_SIGN) && !(flags & PKCS7_STREAM)) {
 564             if (!PKCS7_final(p7, in, flags))
 565                 goto end;
 566         }
 567     }
 568
 569     if (p7 == NULL) {
 570         BIO_printf(bio_err, "Error creating PKCS#7 structure\n");
 571         goto end;
 572     }
 573
 574     ret = 4;
 575     if (operation == SMIME_DECRYPT) {
 576         if (!PKCS7_decrypt(p7, key, recip, out, flags)) {
 577             BIO_printf(bio_err, "Error decrypting PKCS#7 structure\n");
 578             goto end;
 579         }
 580     } else if (operation == SMIME_VERIFY) {
 581         STACK_OF(X509) *signers;
 582         if (PKCS7_verify(p7, other, store, indata, out, flags))
 583             BIO_printf(bio_err, "Verification successful\n");
 584         else {
 585             BIO_printf(bio_err, "Verification failure\n");
 586             goto end;
 587         }
 588         signers = PKCS7_get0_signers(p7, other, flags);
 589         if (!save_certs(signerfile, signers)) {
 590             BIO_printf(bio_err, "Error writing signers to %s\n", signerfile);
 591             ret = 5;
 592             goto end;
 593         }
 594         sk_X509_free(signers);
 595     } else if (operation == SMIME_PK7OUT) {
 596         PEM_write_bio_PKCS7(out, p7);
 597     } else {
 598         if (to)
 599             BIO_printf(out, "To: %s%s", to, mime_eol);
 600         if (from)
 601             BIO_printf(out, "From: %s%s", from, mime_eol);
 602         if (subject)
 603             BIO_printf(out, "Subject: %s%s", subject, mime_eol);
 604         if (outformat == FORMAT_SMIME) {
 605             if (operation == SMIME_RESIGN)
 606                 rv = SMIME_write_PKCS7(out, p7, indata, flags);
 607             else
 608                 rv = SMIME_write_PKCS7(out, p7, in, flags);
 609         } else if (outformat == FORMAT_PEM) {
 610             rv = PEM_write_bio_PKCS7_stream(out, p7, in, flags);
 611         } else if (outformat == FORMAT_ASN1) {
 612             rv = i2d_PKCS7_bio_stream(out, p7, in, flags);
 613         } else {
 614             BIO_printf(bio_err, "Bad output format for PKCS#7 file\n");
 615             goto end;
 616         }
 617         if (rv == 0) {
 618             BIO_printf(bio_err, "Error writing output\n");
 619             ret = 3;
 620             goto end;
 621         }
 622     }
 623     ret = 0;
 624  end:
 625     if (ret)
 626         ERR_print_errors(bio_err);
 627     sk_X509_pop_free(encerts, X509_free);
 628     sk_X509_pop_free(other, X509_free);
 629     X509_VERIFY_PARAM_free(vpm);
 630     sk_OPENSSL_STRING_free(sksigners);
 631     sk_OPENSSL_STRING_free(skkeys);
 632     X509_STORE_free(store);
 633     X509_free(cert);
 634     X509_free(recip);
 635     X509_free(signer);
 636     EVP_PKEY_free(key);
 637     PKCS7_free(p7);
 638     release_engine(e);
 639     BIO_free(in);
 640     BIO_free(indata);
 641     BIO_free_all(out);
 642     OPENSSL_free(passin);
 643     return ret;
 644 }
 645
 646 static int save_certs(char *signerfile, STACK_OF(X509) *signers)
 647 {
 648     int i;
 649     BIO *tmp;
 650
 651     if (signerfile == NULL)
 652         return 1;
 653     tmp = BIO_new_file(signerfile, "w");
 654     if (tmp == NULL)
 655         return 0;
 656     for (i = 0; i < sk_X509_num(signers); i++)
 657         PEM_write_bio_X509(tmp, sk_X509_value(signers, i));
 658     BIO_free(tmp);
 659     return 1;
 660 }
 661
 662 /* Minimal callback just to output policy info (if any) */
 663
 664 static int smime_cb(int ok, X509_STORE_CTX *ctx)
 665 {
 666     int error;
 667
 668     error = X509_STORE_CTX_get_error(ctx);
 669
 670     if ((error != X509_V_ERR_NO_EXPLICIT_POLICY)
 671         && ((error != X509_V_OK) || (ok != 2)))
 672         return ok;
 673
 674     policies_print(ctx);
 675
 676     return ok;
 677 }