demos/cms/cms_enc.c

   1 /* Simple S/MIME encrypt example */
   2 #include <openssl/pem.h>
   3 #include <openssl/cms.h>
   4 #include <openssl/err.h>
   5
   6 int main(int argc, char **argv)
   7 {
   8     BIO *in = NULL, *out = NULL, *tbio = NULL;
   9     X509 *rcert = NULL;
  10     STACK_OF(X509) *recips = NULL;
  11     CMS_ContentInfo *cms = NULL;
  12     int ret = 1;
  13
  14     /*
  15      * On OpenSSL 1.0.0 and later only:
  16      * for streaming set CMS_STREAM
  17      */
  18     int flags = CMS_STREAM;
  19
  20     OpenSSL_add_all_algorithms();
  21     ERR_load_crypto_strings();
  22
  23     /* Read in recipient certificate */
  24     tbio = BIO_new_file("signer.pem", "r");
  25
  26     if (!tbio)
  27         goto err;
  28
  29     rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
  30
  31     if (!rcert)
  32         goto err;
  33
  34     /* Create recipient STACK and add recipient cert to it */
  35     recips = sk_X509_new_null();
  36
  37     if (!recips || !sk_X509_push(recips, rcert))
  38         goto err;
  39
  40     /*
  41      * sk_X509_pop_free will free up recipient STACK and its contents so set
  42      * rcert to NULL so it isn't freed up twice.
  43      */
  44     rcert = NULL;
  45
  46     /* Open content being encrypted */
  47
  48     in = BIO_new_file("encr.txt", "r");
  49
  50     if (!in)
  51         goto err;
  52
  53     /* encrypt content */
  54     cms = CMS_encrypt(recips, in, EVP_des_ede3_cbc(), flags);
  55
  56     if (!cms)
  57         goto err;
  58
  59     out = BIO_new_file("smencr.txt", "w");
  60     if (!out)
  61         goto err;
  62
  63     /* Write out S/MIME message */
  64     if (!SMIME_write_CMS(out, cms, in, flags))
  65         goto err;
  66
  67     ret = 0;
  68
  69  err:
  70
  71     if (ret) {
  72         fprintf(stderr, "Error Encrypting Data\n");
  73         ERR_print_errors_fp(stderr);
  74     }
  75
  76     if (cms)
  77         CMS_ContentInfo_free(cms);
  78     if (rcert)
  79         X509_free(rcert);
  80     if (recips)
  81         sk_X509_pop_free(recips, X509_free);
  82
  83     if (in)
  84         BIO_free(in);
  85     if (out)
  86         BIO_free(out);
  87     if (tbio)
  88         BIO_free(tbio);
  89
  90     return ret;
  91
  92 }