cms_sign.c
1.93 KB
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/*
* Copyright 2008-2016 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
*/
/* Simple S/MIME signing example */
#include <openssl/pem.h>
#include <openssl/cms.h>
#include <openssl/err.h>
int main(int argc, char **argv)
{
BIO *in = NULL, *out = NULL, *tbio = NULL;
X509 *scert = NULL;
EVP_PKEY *skey = NULL;
CMS_ContentInfo *cms = NULL;
int ret = 1;
/*
* For simple S/MIME signing use CMS_DETACHED. On OpenSSL 1.0.0 only: for
* streaming detached set CMS_DETACHED|CMS_STREAM for streaming
* non-detached set CMS_STREAM
*/
int flags = CMS_DETACHED | CMS_STREAM;
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
/* Read in signer certificate and private key */
tbio = BIO_new_file("signer.pem", "r");
if (!tbio)
goto err;
scert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
BIO_reset(tbio);
skey = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL);
if (!scert || !skey)
goto err;
/* Open content being signed */
in = BIO_new_file("sign.txt", "r");
if (!in)
goto err;
/* Sign content */
cms = CMS_sign(scert, skey, NULL, in, flags);
if (!cms)
goto err;
out = BIO_new_file("smout.txt", "w");
if (!out)
goto err;
if (!(flags & CMS_STREAM))
BIO_reset(in);
/* Write out S/MIME message */
if (!SMIME_write_CMS(out, cms, in, flags))
goto err;
ret = 0;
err:
if (ret) {
fprintf(stderr, "Error Signing Data\n");
ERR_print_errors_fp(stderr);
}
CMS_ContentInfo_free(cms);
X509_free(scert);
EVP_PKEY_free(skey);
BIO_free(in);
BIO_free(out);
BIO_free(tbio);
return ret;
}