1/* 2 * Copyright 2008-2016 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 signing example */ 11#include <openssl/pem.h> 12#include <openssl/cms.h> 13#include <openssl/err.h> 14 15int main(int argc, char **argv) 16{ 17 BIO *in = NULL, *out = NULL, *tbio = NULL; 18 X509 *scert = NULL; 19 EVP_PKEY *skey = NULL; 20 CMS_ContentInfo *cms = NULL; 21 int ret = 1; 22 23 /* 24 * For simple S/MIME signing use CMS_DETACHED. On OpenSSL 1.0.0 only: for 25 * streaming detached set CMS_DETACHED|CMS_STREAM for streaming 26 * non-detached set CMS_STREAM 27 */ 28 int flags = CMS_DETACHED | CMS_STREAM; 29 30 OpenSSL_add_all_algorithms(); 31 ERR_load_crypto_strings(); 32 33 /* Read in signer certificate and private key */ 34 tbio = BIO_new_file("signer.pem", "r"); 35 36 if (!tbio) 37 goto err; 38 39 scert = PEM_read_bio_X509(tbio, NULL, 0, NULL); 40 41 BIO_reset(tbio); 42 43 skey = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL); 44 45 if (!scert || !skey) 46 goto err; 47 48 /* Open content being signed */ 49 50 in = BIO_new_file("sign.txt", "r"); 51 52 if (!in) 53 goto err; 54 55 /* Sign content */ 56 cms = CMS_sign(scert, skey, NULL, in, flags); 57 58 if (!cms) 59 goto err; 60 61 out = BIO_new_file("smout.txt", "w"); 62 if (!out) 63 goto err; 64 65 if (!(flags & CMS_STREAM)) 66 BIO_reset(in); 67 68 /* Write out S/MIME message */ 69 if (!SMIME_write_CMS(out, cms, in, flags)) 70 goto err; 71 72 ret = 0; 73 74 err: 75 76 if (ret) { 77 fprintf(stderr, "Error Signing Data\n"); 78 ERR_print_errors_fp(stderr); 79 } 80 81 CMS_ContentInfo_free(cms); 82 X509_free(scert); 83 EVP_PKEY_free(skey); 84 BIO_free(in); 85 BIO_free(out); 86 BIO_free(tbio); 87 return ret; 88} 89