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 *rcert = NULL; 10 EVP_PKEY *rkey = NULL; 11 PKCS7 *p7 = NULL; 12 int ret = 1; 13 14 OpenSSL_add_all_algorithms(); 15 ERR_load_crypto_strings(); 16 17 /* Read in recipient certificate and private key */ 18 tbio = BIO_new_file("signer.pem", "r"); 19 20 if (!tbio) 21 goto err; 22 23 rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL); 24 25 BIO_reset(tbio); 26 27 rkey = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL); 28 29 if (!rcert || !rkey) 30 goto err; 31 32 /* Open content being signed */ 33 34 in = BIO_new_file("smencr.txt", "r"); 35 36 if (!in) 37 goto err; 38 39 /* Sign content */ 40 p7 = SMIME_read_PKCS7(in, NULL); 41 42 if (!p7) 43 goto err; 44 45 out = BIO_new_file("encrout.txt", "w"); 46 if (!out) 47 goto err; 48 49 /* Decrypt S/MIME message */ 50 if (!PKCS7_decrypt(p7, rkey, rcert, out, 0)) 51 goto err; 52 53 ret = 0; 54 55 err: 56 57 if (ret) 58 { 59 fprintf(stderr, "Error Signing Data\n"); 60 ERR_print_errors_fp(stderr); 61 } 62 63 if (p7) 64 PKCS7_free(p7); 65 if (rcert) 66 X509_free(rcert); 67 if (rkey) 68 EVP_PKEY_free(rkey); 69 70 if (in) 71 BIO_free(in); 72 if (out) 73 BIO_free(out); 74 if (tbio) 75 BIO_free(tbio); 76 77 return ret; 78 79 } 80 81 82 83 84