1 /* Simple S/MIME signing example */
2 #include <openssl/pem.h>
3 #include <openssl/cms.h>
4 #include <openssl/err.h>
5
main(int argc,char ** argv)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 CMS_ContentInfo *cms = NULL;
12 int ret = 1;
13
14 /*
15 * For simple S/MIME signing use CMS_DETACHED. On OpenSSL 1.0.0 only: for
16 * streaming detached set CMS_DETACHED|CMS_STREAM for streaming
17 * non-detached set CMS_STREAM
18 */
19 int flags = CMS_DETACHED | CMS_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 cms = CMS_sign(scert, skey, NULL, in, flags);
48
49 if (!cms)
50 goto err;
51
52 out = BIO_new_file("smout.txt", "w");
53 if (!out)
54 goto err;
55
56 if (!(flags & CMS_STREAM))
57 BIO_reset(in);
58
59 /* Write out S/MIME message */
60 if (!SMIME_write_CMS(out, cms, in, flags))
61 goto err;
62
63 ret = 0;
64
65 err:
66
67 if (ret) {
68 fprintf(stderr, "Error Signing Data\n");
69 ERR_print_errors_fp(stderr);
70 }
71
72 if (cms)
73 CMS_ContentInfo_free(cms);
74 if (scert)
75 X509_free(scert);
76 if (skey)
77 EVP_PKEY_free(skey);
78
79 if (in)
80 BIO_free(in);
81 if (out)
82 BIO_free(out);
83 if (tbio)
84 BIO_free(tbio);
85
86 return ret;
87
88 }
89