demos/cms/cms_enc.c

   1 /*
   2  * Copyright 2008-2023 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 S/MIME encrypt example */
  11 #include <openssl/pem.h>
  12 #include <openssl/cms.h>
  13 #include <openssl/err.h>
  14
  15 int main(int argc, char **argv)
  16 {
  17     BIO *in = NULL, *out = NULL, *tbio = NULL;
  18     X509 *rcert = NULL;
  19     STACK_OF(X509) *recips = NULL;
  20     CMS_ContentInfo *cms = NULL;
  21     int ret = EXIT_FAILURE;
  22
  23     /*
  24      * On OpenSSL 1.0.0 and later only:
  25      * for streaming set CMS_STREAM
  26      */
  27     int flags = CMS_STREAM;
  28
  29     OpenSSL_add_all_algorithms();
  30     ERR_load_crypto_strings();
  31
  32     /* Read in recipient certificate */
  33     tbio = BIO_new_file("signer.pem", "r");
  34
  35     if (!tbio)
  36         goto err;
  37
  38     rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
  39
  40     if (!rcert)
  41         goto err;
  42
  43     /* Create recipient STACK and add recipient cert to it */
  44     recips = sk_X509_new_null();
  45
  46     if (!recips || !sk_X509_push(recips, rcert))
  47         goto err;
  48
  49     /*
  50      * OSSL_STACK_OF_X509_free() will free up recipient STACK and its contents
  51      * so set rcert to NULL so it isn't freed up twice.
  52      */
  53     rcert = NULL;
  54
  55     /* Open content being encrypted */
  56
  57     in = BIO_new_file("encr.txt", "r");
  58
  59     if (!in)
  60         goto err;
  61
  62     /* encrypt content */
  63     cms = CMS_encrypt(recips, in, EVP_des_ede3_cbc(), flags);
  64
  65     if (!cms)
  66         goto err;
  67
  68     out = BIO_new_file("smencr.txt", "w");
  69     if (!out)
  70         goto err;
  71
  72     /* Write out S/MIME message */
  73     if (!SMIME_write_CMS(out, cms, in, flags))
  74         goto err;
  75
  76     ret = EXIT_SUCCESS;
  77  err:
  78     if (ret != EXIT_SUCCESS) {
  79         fprintf(stderr, "Error Encrypting Data\n");
  80         ERR_print_errors_fp(stderr);
  81     }
  82
  83     CMS_ContentInfo_free(cms);
  84     X509_free(rcert);
  85     OSSL_STACK_OF_X509_free(recips);
  86     BIO_free(in);
  87     BIO_free(out);
  88     BIO_free(tbio);
  89     return ret;
  90 }