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 signing example */
11 #include <openssl/pem.h>
12 #include <openssl/cms.h>
13 #include <openssl/err.h>
14
main(int argc,char ** argv)15 int 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 = EXIT_FAILURE;
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 if (BIO_reset(tbio) < 0)
42 goto err;
43
44 skey = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL);
45
46 if (!scert || !skey)
47 goto err;
48
49 /* Open content being signed */
50
51 in = BIO_new_file("sign.txt", "r");
52
53 if (!in)
54 goto err;
55
56 /* Sign content */
57 cms = CMS_sign(scert, skey, NULL, in, flags);
58
59 if (!cms)
60 goto err;
61
62 out = BIO_new_file("smout.txt", "w");
63 if (!out)
64 goto err;
65
66 if (!(flags & CMS_STREAM)) {
67 if (BIO_reset(in) < 0)
68 goto err;
69 }
70
71 /* Write out S/MIME message */
72 if (!SMIME_write_CMS(out, cms, in, flags))
73 goto err;
74
75 ret = EXIT_SUCCESS;
76 err:
77 if (ret != EXIT_SUCCESS) {
78 fprintf(stderr, "Error Signing Data\n");
79 ERR_print_errors_fp(stderr);
80 }
81
82 CMS_ContentInfo_free(cms);
83 X509_free(scert);
84 EVP_PKEY_free(skey);
85 BIO_free(in);
86 BIO_free(out);
87 BIO_free(tbio);
88 return ret;
89 }
90
