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/* S/MIME detached data encrypt example: rarely done but
* should the need arise this is an 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, *dout = NULL;
X509 *rcert = NULL;
STACK_OF(X509) *recips = NULL;
CMS_ContentInfo *cms = NULL;
int ret = 1;
int flags = CMS_STREAM|CMS_DETACHED;
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
/* Read in recipient certificate */
tbio = BIO_new_file("signer.pem", "r");
if (!tbio)
goto err;
rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
if (!rcert)
goto err;
/* Create recipient STACK and add recipient cert to it */
recips = sk_X509_new_null();
if (!recips || !sk_X509_push(recips, rcert))
goto err;
/* sk_X509_pop_free will free up recipient STACK and its contents
* so set rcert to NULL so it isn't freed up twice.
*/
rcert = NULL;
/* Open content being encrypted */
in = BIO_new_file("encr.txt", "r");
dout = BIO_new_file("smencr.out", "wb");
if (!in)
goto err;
/* encrypt content */
cms = CMS_encrypt(recips, in, EVP_des_ede3_cbc(), flags);
if (!cms)
goto err;
out = BIO_new_file("smencr.pem", "w");
if (!out)
goto err;
if (!CMS_final(cms, in, dout, flags))
goto err;
/* Write out CMS structure without content */
if (!PEM_write_bio_CMS(out, cms))
goto err;
ret = 0;
err:
if (ret)
{
fprintf(stderr, "Error Encrypting Data\n");
ERR_print_errors_fp(stderr);
}
if (cms)
CMS_ContentInfo_free(cms);
if (rcert)
X509_free(rcert);
if (recips)
sk_X509_pop_free(recips, X509_free);
if (in)
BIO_free(in);
if (out)
BIO_free(out);
if (dout)
BIO_free(dout);
if (tbio)
BIO_free(tbio);
return ret;
}