demos/smime/smsign.c

   1 /* Simple S/MIME signing example */
   2 #include <openssl/pem.h>
   3 #include <openssl/pkcs7.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 *scert = NULL;
  10     EVP_PKEY *skey = NULL;
  11     PKCS7 *p7 = NULL;
  12     int ret = 1;
  13
  14     /*
  15      * For simple S/MIME signing use PKCS7_DETACHED. On OpenSSL 0.9.9 only:
  16      * for streaming detached set PKCS7_DETACHED|PKCS7_STREAM for streaming
  17      * non-detached set PKCS7_STREAM
  18      */
  19     int flags = PKCS7_DETACHED | PKCS7_STREAM;
  20
  21     OpenSSL_add_all_algorithms();
  22     ERR_load_crypto_strings();
  23
  24     /* Read in signer certificate and private key */
  25     tbio = BIO_new_file("signer.pem", "r");
  26
  27     if (!tbio)
  28         goto err;
  29
  30     scert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
  31
  32     BIO_reset(tbio);
  33
  34     skey = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL);
  35
  36     if (!scert || !skey)
  37         goto err;
  38
  39     /* Open content being signed */
  40
  41     in = BIO_new_file("sign.txt", "r");
  42
  43     if (!in)
  44         goto err;
  45
  46     /* Sign content */
  47     p7 = PKCS7_sign(scert, skey, NULL, in, flags);
  48
  49     if (!p7)
  50         goto err;
  51
  52     out = BIO_new_file("smout.txt", "w");
  53     if (!out)
  54         goto err;
  55
  56     if (!(flags & PKCS7_STREAM))
  57         BIO_reset(in);
  58
  59     /* Write out S/MIME message */
  60     if (!SMIME_write_PKCS7(out, p7, in, flags))
  61         goto err;
  62
  63     ret = 0;
  64
  65  err:
  66     if (ret) {
  67         fprintf(stderr, "Error Signing Data\n");
  68         ERR_print_errors_fp(stderr);
  69     }
  70     PKCS7_free(p7);
  71     X509_free(scert);
  72     EVP_PKEY_free(skey);
  73     BIO_free(in);
  74     BIO_free(out);
  75     BIO_free(tbio);
  76
  77     return ret;
  78
  79 }