/*
* Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/* S/MIME utility function */
#include <stdio.h>
#include <string.h>
#include "apps.h"
#include "progs.h"
#include <openssl/crypto.h>
#include <openssl/pem.h>
#include <openssl/err.h>
#include <openssl/x509_vfy.h>
#include <openssl/x509v3.h>
static int save_certs(char *signerfile, STACK_OF(X509) *signers);
static int smime_cb(int ok, X509_STORE_CTX *ctx);
#define SMIME_OP 0x10
#define SMIME_IP 0x20
#define SMIME_SIGNERS 0x40
#define SMIME_ENCRYPT (1 | SMIME_OP)
#define SMIME_DECRYPT (2 | SMIME_IP)
#define SMIME_SIGN (3 | SMIME_OP | SMIME_SIGNERS)
#define SMIME_VERIFY (4 | SMIME_IP)
#define SMIME_PK7OUT (5 | SMIME_IP | SMIME_OP)
#define SMIME_RESIGN (6 | SMIME_IP | SMIME_OP | SMIME_SIGNERS)
typedef enum OPTION_choice {
OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
OPT_ENCRYPT, OPT_DECRYPT, OPT_SIGN, OPT_RESIGN, OPT_VERIFY,
OPT_PK7OUT, OPT_TEXT, OPT_NOINTERN, OPT_NOVERIFY, OPT_NOCHAIN,
OPT_NOCERTS, OPT_NOATTR, OPT_NODETACH, OPT_NOSMIMECAP,
OPT_BINARY, OPT_NOSIGS, OPT_STREAM, OPT_INDEF, OPT_NOINDEF,
OPT_CRLFEOL, OPT_ENGINE, OPT_PASSIN,
OPT_TO, OPT_FROM, OPT_SUBJECT, OPT_SIGNER, OPT_RECIP, OPT_MD,
OPT_CIPHER, OPT_INKEY, OPT_KEYFORM, OPT_CERTFILE, OPT_CAFILE,
OPT_R_ENUM,
OPT_V_ENUM,
OPT_CAPATH, OPT_NOCAFILE, OPT_NOCAPATH, OPT_IN, OPT_INFORM, OPT_OUT,
OPT_OUTFORM, OPT_CONTENT
} OPTION_CHOICE;
const OPTIONS smime_options[] = {
{OPT_HELP_STR, 1, '-', "Usage: %s [options] cert.pem...\n"},
{OPT_HELP_STR, 1, '-',
" cert.pem... recipient certs for encryption\n"},
{OPT_HELP_STR, 1, '-', "Valid options are:\n"},
{"help", OPT_HELP, '-', "Display this summary"},
{"encrypt", OPT_ENCRYPT, '-', "Encrypt message"},
{"decrypt", OPT_DECRYPT, '-', "Decrypt encrypted message"},
{"sign", OPT_SIGN, '-', "Sign message"},
{"verify", OPT_VERIFY, '-', "Verify signed message"},
{"pk7out", OPT_PK7OUT, '-', "Output PKCS#7 structure"},
{"nointern", OPT_NOINTERN, '-',
"Don't search certificates in message for signer"},
{"nosigs", OPT_NOSIGS, '-', "Don't verify message signature"},
{"noverify", OPT_NOVERIFY, '-', "Don't verify signers certificate"},
{"nocerts", OPT_NOCERTS, '-',
"Don't include signers certificate when signing"},
{"nodetach", OPT_NODETACH, '-', "Use opaque signing"},
{"noattr", OPT_NOATTR, '-', "Don't include any signed attributes"},
{"binary", OPT_BINARY, '-', "Don't translate message to text"},
{"certfile", OPT_CERTFILE, '<', "Other certificates file"},
{"signer", OPT_SIGNER, 's', "Signer certificate file"},
{"recip", OPT_RECIP, '<', "Recipient certificate file for decryption"},
{"in", OPT_IN, '<', "Input file"},
{"inform", OPT_INFORM, 'c', "Input format SMIME (default), PEM or DER"},
{"inkey", OPT_INKEY, 's',
"Input private key (if not signer or recipient)"},
{"keyform", OPT_KEYFORM, 'f', "Input private key format (PEM or ENGINE)"},
{"out", OPT_OUT, '>', "Output file"},
{"outform", OPT_OUTFORM, 'c',
"Output format SMIME (default), PEM or DER"},
{"content", OPT_CONTENT, '<',
"Supply or override content for detached signature"},
{"to", OPT_TO, 's', "To address"},
{"from", OPT_FROM, 's', "From address"},
{"subject", OPT_SUBJECT, 's', "Subject"},
{"text", OPT_TEXT, '-', "Include or delete text MIME headers"},
{"CApath", OPT_CAPATH, '/', "Trusted certificates directory"},
{"CAfile", OPT_CAFILE, '<', "Trusted certificates file"},
{"no-CAfile", OPT_NOCAFILE, '-',
"Do not load the default certificates file"},
{"no-CApath", OPT_NOCAPATH, '-',
"Do not load certificates from the default certificates directory"},
{"resign", OPT_RESIGN, '-', "Resign a signed message"},
{"nochain", OPT_NOCHAIN, '-',
"set PKCS7_NOCHAIN so certificates contained in the message are not used as untrusted CAs" },
{"nosmimecap", OPT_NOSMIMECAP, '-', "Omit the SMIMECapabilities attribute"},
{"stream", OPT_STREAM, '-', "Enable CMS streaming" },
{"indef", OPT_INDEF, '-', "Same as -stream" },
{"noindef", OPT_NOINDEF, '-', "Disable CMS streaming"},
{"crlfeol", OPT_CRLFEOL, '-', "Use CRLF as EOL termination instead of CR only"},
OPT_R_OPTIONS,
{"passin", OPT_PASSIN, 's', "Input file pass phrase source"},
{"md", OPT_MD, 's', "Digest algorithm to use when signing or resigning"},
{"", OPT_CIPHER, '-', "Any supported cipher"},
OPT_V_OPTIONS,
#ifndef OPENSSL_NO_ENGINE
{"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
#endif
{NULL}
};
int smime_main(int argc, char **argv)
{
BIO *in = NULL, *out = NULL, *indata = NULL;
EVP_PKEY *key = NULL;
PKCS7 *p7 = NULL;
STACK_OF(OPENSSL_STRING) *sksigners = NULL, *skkeys = NULL;
STACK_OF(X509) *encerts = NULL, *other = NULL;
X509 *cert = NULL, *recip = NULL, *signer = NULL;
X509_STORE *store = NULL;
X509_VERIFY_PARAM *vpm = NULL;
const EVP_CIPHER *cipher = NULL;
const EVP_MD *sign_md = NULL;
const char *CAfile = NULL, *CApath = NULL, *prog = NULL;
char *certfile = NULL, *keyfile = NULL, *contfile = NULL;
char *infile = NULL, *outfile = NULL, *signerfile = NULL, *recipfile = NULL;
char *passinarg = NULL, *passin = NULL, *to = NULL, *from = NULL, *subject = NULL;
OPTION_CHOICE o;
int noCApath = 0, noCAfile = 0;
int flags = PKCS7_DETACHED, operation = 0, ret = 0, indef = 0;
int informat = FORMAT_SMIME, outformat = FORMAT_SMIME, keyform =
FORMAT_PEM;
int vpmtouched = 0, rv = 0;
ENGINE *e = NULL;
const char *mime_eol = "\n";
if ((vpm = X509_VERIFY_PARAM_new()) == NULL)
return 1;
prog = opt_init(argc, argv, smime_options);
while ((o = opt_next()) != OPT_EOF) {
switch (o) {
case OPT_EOF:
case OPT_ERR:
opthelp:
BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
goto end;
case OPT_HELP:
opt_help(smime_options);
ret = 0;
goto end;
case OPT_INFORM:
if (!opt_format(opt_arg(), OPT_FMT_PDS, &informat))
goto opthelp;
break;
case OPT_IN:
infile = opt_arg();
break;
case OPT_OUTFORM:
if (!opt_format(opt_arg(), OPT_FMT_PDS, &outformat))
goto opthelp;
break;
case OPT_OUT:
outfile = opt_arg();
break;
case OPT_ENCRYPT:
operation = SMIME_ENCRYPT;
break;
case OPT_DECRYPT:
operation = SMIME_DECRYPT;
break;
case OPT_SIGN:
operation = SMIME_SIGN;
break;
case OPT_RESIGN:
operation = SMIME_RESIGN;
break;
case OPT_VERIFY:
operation = SMIME_VERIFY;
break;
case OPT_PK7OUT:
operation = SMIME_PK7OUT;
break;
case OPT_TEXT:
flags |= PKCS7_TEXT;
break;
case OPT_NOINTERN:
flags |= PKCS7_NOINTERN;
break;
case OPT_NOVERIFY:
flags |= PKCS7_NOVERIFY;
break;
case OPT_NOCHAIN:
flags |= PKCS7_NOCHAIN;
break;
case OPT_NOCERTS:
flags |= PKCS7_NOCERTS;
break;
case OPT_NOATTR:
flags |= PKCS7_NOATTR;
break;
case OPT_NODETACH:
flags &= ~PKCS7_DETACHED;
break;
case OPT_NOSMIMECAP:
flags |= PKCS7_NOSMIMECAP;
break;
case OPT_BINARY:
flags |= PKCS7_BINARY;
break;
case OPT_NOSIGS:
flags |= PKCS7_NOSIGS;
break;
case OPT_STREAM:
case OPT_INDEF:
indef = 1;
break;
case OPT_NOINDEF:
indef = 0;
break;
case OPT_CRLFEOL:
flags |= PKCS7_CRLFEOL;
mime_eol = "\r\n";
break;
case OPT_R_CASES:
if (!opt_rand(o))
goto end;
break;
case OPT_ENGINE:
e = setup_engine(opt_arg(), 0);
break;
case OPT_PASSIN:
passinarg = opt_arg();
break;
case OPT_TO:
to = opt_arg();
break;
case OPT_FROM:
from = opt_arg();
break;
case OPT_SUBJECT:
subject = opt_arg();
break;
case OPT_SIGNER:
/* If previous -signer argument add signer to list */
if (signerfile != NULL) {
if (sksigners == NULL
&& (sksigners = sk_OPENSSL_STRING_new_null()) == NULL)
goto end;
sk_OPENSSL_STRING_push(sksigners, signerfile);
if (keyfile == NULL)
keyfile = signerfile;
if (skkeys == NULL
&& (skkeys = sk_OPENSSL_STRING_new_null()) == NULL)
goto end;
sk_OPENSSL_STRING_push(skkeys, keyfile);
keyfile = NULL;
}
signerfile = opt_arg();
break;
case OPT_RECIP:
recipfile = opt_arg();
break;
case OPT_MD:
if (!opt_md(opt_arg(), &sign_md))
goto opthelp;
break;
case OPT_CIPHER:
if (!opt_cipher(opt_unknown(), &cipher))
goto opthelp;
break;
case OPT_INKEY:
/* If previous -inkey argument add signer to list */
if (keyfile != NULL) {
if (signerfile == NULL) {
BIO_printf(bio_err,
"%s: Must have -signer before -inkey\n", prog);
goto opthelp;
}
if (sksigners == NULL
&& (sksigners = sk_OPENSSL_STRING_new_null()) == NULL)
goto end;
sk_OPENSSL_STRING_push(sksigners, signerfile);
signerfile = NULL;
if (skkeys == NULL
&& (skkeys = sk_OPENSSL_STRING_new_null()) == NULL)
goto end;
sk_OPENSSL_STRING_push(skkeys, keyfile);
}
keyfile = opt_arg();
break;
case OPT_KEYFORM:
if (!opt_format(opt_arg(), OPT_FMT_ANY, &keyform))
goto opthelp;
break;
case OPT_CERTFILE:
certfile = opt_arg();
break;
case OPT_CAFILE:
CAfile = opt_arg();
break;
case OPT_CAPATH:
CApath = opt_arg();
break;
case OPT_NOCAFILE:
noCAfile = 1;
break;
case OPT_NOCAPATH:
noCApath = 1;
break;
case OPT_CONTENT:
contfile = opt_arg();
break;
case OPT_V_CASES:
if (!opt_verify(o, vpm))
goto opthelp;
vpmtouched++;
break;
}
}
argc = opt_num_rest();
argv = opt_rest();
if (!(operation & SMIME_SIGNERS) && (skkeys != NULL || sksigners != NULL)) {
BIO_puts(bio_err, "Multiple signers or keys not allowed\n");
goto opthelp;
}
if (operation & SMIME_SIGNERS) {
/* Check to see if any final signer needs to be appended */
if (keyfile && !signerfile) {
BIO_puts(bio_err, "Illegal -inkey without -signer\n");
goto opthelp;
}
if (signerfile != NULL) {
if (sksigners == NULL
&& (sksigners = sk_OPENSSL_STRING_new_null()) == NULL)
goto end;
sk_OPENSSL_STRING_push(sksigners, signerfile);
if (!skkeys && (skkeys = sk_OPENSSL_STRING_new_null()) == NULL)
goto end;
if (!keyfile)
keyfile = signerfile;
sk_OPENSSL_STRING_push(skkeys, keyfile);
}
if (sksigners == NULL) {
BIO_printf(bio_err, "No signer certificate specified\n");
goto opthelp;
}
signerfile = NULL;
keyfile = NULL;
} else if (operation == SMIME_DECRYPT) {
if (recipfile == NULL && keyfile == NULL) {
BIO_printf(bio_err,
"No recipient certificate or key specified\n");
goto opthelp;
}
} else if (operation == SMIME_ENCRYPT) {
if (argc == 0) {
BIO_printf(bio_err, "No recipient(s) certificate(s) specified\n");
goto opthelp;
}
} else if (!operation) {
goto opthelp;
}
if (!app_passwd(passinarg, NULL, &passin, NULL)) {
BIO_printf(bio_err, "Error getting password\n");
goto end;
}
ret = 2;
if (!(operation & SMIME_SIGNERS))
flags &= ~PKCS7_DETACHED;
if (!(operation & SMIME_OP)) {
if (flags & PKCS7_BINARY)
outformat = FORMAT_BINARY;
}
if (!(operation & SMIME_IP)) {
if (flags & PKCS7_BINARY)
informat = FORMAT_BINARY;
}
if (operation == SMIME_ENCRYPT) {
if (cipher == NULL) {
#ifndef OPENSSL_NO_DES
cipher = EVP_des_ede3_cbc();
#else
BIO_printf(bio_err, "No cipher selected\n");
goto end;
#endif
}
encerts = sk_X509_new_null();
if (encerts == NULL)
goto end;
while (*argv != NULL) {
cert = load_cert(*argv, FORMAT_PEM,
"recipient certificate file");
if (cert == NULL)
goto end;
sk_X509_push(encerts, cert);
cert = NULL;
argv++;
}
}
if (certfile != NULL) {
if (!load_certs(certfile, &other, FORMAT_PEM, NULL,
"certificate file")) {
ERR_print_errors(bio_err);
goto end;
}
}
if (recipfile != NULL && (operation == SMIME_DECRYPT)) {
if ((recip = load_cert(recipfile, FORMAT_PEM,
"recipient certificate file")) == NULL) {
ERR_print_errors(bio_err);
goto end;
}
}
if (operation == SMIME_DECRYPT) {
if (keyfile == NULL)
keyfile = recipfile;
} else if (operation == SMIME_SIGN) {
if (keyfile == NULL)
keyfile = signerfile;
} else {
keyfile = NULL;
}
if (keyfile != NULL) {
key = load_key(keyfile, keyform, 0, passin, e, "signing key file");
if (key == NULL)
goto end;
}
in = bio_open_default(infile, 'r', informat);
if (in == NULL)
goto end;
if (operation & SMIME_IP) {
if (informat == FORMAT_SMIME) {
p7 = SMIME_read_PKCS7(in, &indata);
} else if (informat == FORMAT_PEM) {
p7 = PEM_read_bio_PKCS7(in, NULL, NULL, NULL);
} else if (informat == FORMAT_ASN1) {
p7 = d2i_PKCS7_bio(in, NULL);
} else {
BIO_printf(bio_err, "Bad input format for PKCS#7 file\n");
goto end;
}
if (p7 == NULL) {
BIO_printf(bio_err, "Error reading S/MIME message\n");
goto end;
}
if (contfile != NULL) {
BIO_free(indata);
if ((indata = BIO_new_file(contfile, "rb")) == NULL) {
BIO_printf(bio_err, "Can't read content file %s\n", contfile);
goto end;
}
}
}
out = bio_open_default(outfile, 'w', outformat);
if (out == NULL)
goto end;
if (operation == SMIME_VERIFY) {
if ((store = setup_verify(CAfile, CApath, noCAfile, noCApath)) == NULL)
goto end;
X509_STORE_set_verify_cb(store, smime_cb);
if (vpmtouched)
X509_STORE_set1_param(store, vpm);
}
ret = 3;
if (operation == SMIME_ENCRYPT) {
if (indef)
flags |= PKCS7_STREAM;
p7 = PKCS7_encrypt(encerts, in, cipher, flags);
} else if (operation & SMIME_SIGNERS) {
int i;
/*
* If detached data content we only enable streaming if S/MIME output
* format.
*/
if (operation == SMIME_SIGN) {
if (flags & PKCS7_DETACHED) {
if (outformat == FORMAT_SMIME)
flags |= PKCS7_STREAM;
} else if (indef) {
flags |= PKCS7_STREAM;
}
flags |= PKCS7_PARTIAL;
p7 = PKCS7_sign(NULL, NULL, other, in, flags);
if (p7 == NULL)
goto end;
if (flags & PKCS7_NOCERTS) {
for (i = 0; i < sk_X509_num(other); i++) {
X509 *x = sk_X509_value(other, i);
PKCS7_add_certificate(p7, x);
}
}
} else {
flags |= PKCS7_REUSE_DIGEST;
}
for (i = 0; i < sk_OPENSSL_STRING_num(sksigners); i++) {
signerfile = sk_OPENSSL_STRING_value(sksigners, i);
keyfile = sk_OPENSSL_STRING_value(skkeys, i);
signer = load_cert(signerfile, FORMAT_PEM,
"signer certificate");
if (signer == NULL)
goto end;
key = load_key(keyfile, keyform, 0, passin, e, "signing key file");
if (key == NULL)
goto end;
if (!PKCS7_sign_add_signer(p7, signer, key, sign_md, flags))
goto end;
X509_free(signer);
signer = NULL;
EVP_PKEY_free(key);
key = NULL;
}
/* If not streaming or resigning finalize structure */
if ((operation == SMIME_SIGN) && !(flags & PKCS7_STREAM)) {
if (!PKCS7_final(p7, in, flags))
goto end;
}
}
if (p7 == NULL) {
BIO_printf(bio_err, "Error creating PKCS#7 structure\n");
goto end;
}
ret = 4;
if (operation == SMIME_DECRYPT) {
if (!PKCS7_decrypt(p7, key, recip, out, flags)) {
BIO_printf(bio_err, "Error decrypting PKCS#7 structure\n");
goto end;
}
} else if (operation == SMIME_VERIFY) {
STACK_OF(X509) *signers;
if (PKCS7_verify(p7, other, store, indata, out, flags))
BIO_printf(bio_err, "Verification successful\n");
else {
BIO_printf(bio_err, "Verification failure\n");
goto end;
}
signers = PKCS7_get0_signers(p7, other, flags);
if (!save_certs(signerfile, signers)) {
BIO_printf(bio_err, "Error writing signers to %s\n", signerfile);
ret = 5;
goto end;
}
sk_X509_free(signers);
} else if (operation == SMIME_PK7OUT) {
PEM_write_bio_PKCS7(out, p7);
} else {
if (to)
BIO_printf(out, "To: %s%s", to, mime_eol);
if (from)
BIO_printf(out, "From: %s%s", from, mime_eol);
if (subject)
BIO_printf(out, "Subject: %s%s", subject, mime_eol);
if (outformat == FORMAT_SMIME) {
if (operation == SMIME_RESIGN)
rv = SMIME_write_PKCS7(out, p7, indata, flags);
else
rv = SMIME_write_PKCS7(out, p7, in, flags);
} else if (outformat == FORMAT_PEM) {
rv = PEM_write_bio_PKCS7_stream(out, p7, in, flags);
} else if (outformat == FORMAT_ASN1) {
rv = i2d_PKCS7_bio_stream(out, p7, in, flags);
} else {
BIO_printf(bio_err, "Bad output format for PKCS#7 file\n");
goto end;
}
if (rv == 0) {
BIO_printf(bio_err, "Error writing output\n");
ret = 3;
goto end;
}
}
ret = 0;
end:
if (ret)
ERR_print_errors(bio_err);
sk_X509_pop_free(encerts, X509_free);
sk_X509_pop_free(other, X509_free);
X509_VERIFY_PARAM_free(vpm);
sk_OPENSSL_STRING_free(sksigners);
sk_OPENSSL_STRING_free(skkeys);
X509_STORE_free(store);
X509_free(cert);
X509_free(recip);
X509_free(signer);
EVP_PKEY_free(key);
PKCS7_free(p7);
release_engine(e);
BIO_free(in);
BIO_free(indata);
BIO_free_all(out);
OPENSSL_free(passin);
return ret;
}
static int save_certs(char *signerfile, STACK_OF(X509) *signers)
{
int i;
BIO *tmp;
if (signerfile == NULL)
return 1;
tmp = BIO_new_file(signerfile, "w");
if (tmp == NULL)
return 0;
for (i = 0; i < sk_X509_num(signers); i++)
PEM_write_bio_X509(tmp, sk_X509_value(signers, i));
BIO_free(tmp);
return 1;
}
/* Minimal callback just to output policy info (if any) */
static int smime_cb(int ok, X509_STORE_CTX *ctx)
{
int error;
error = X509_STORE_CTX_get_error(ctx);
if ((error != X509_V_ERR_NO_EXPLICIT_POLICY)
&& ((error != X509_V_OK) || (ok != 2)))
return ok;
policies_print(ctx);
return ok;
}