1/* Simple S/MIME encrypt example */
2#include <openssl/pem.h>
3#include <openssl/cms.h>
4#include <openssl/err.h>
5
6int main(int argc, char **argv)
7{
8    BIO *in = NULL, *out = NULL, *tbio = NULL;
9    X509 *rcert = NULL;
10    STACK_OF(X509) *recips = NULL;
11    CMS_ContentInfo *cms = NULL;
12    int ret = 1;
13
14    /*
15     * On OpenSSL 1.0.0 and later only:
16     * for streaming set CMS_STREAM
17     */
18    int flags = CMS_STREAM;
19
20    OpenSSL_add_all_algorithms();
21    ERR_load_crypto_strings();
22
23    /* Read in recipient certificate */
24    tbio = BIO_new_file("signer.pem", "r");
25
26    if (!tbio)
27        goto err;
28
29    rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
30
31    if (!rcert)
32        goto err;
33
34    /* Create recipient STACK and add recipient cert to it */
35    recips = sk_X509_new_null();
36
37    if (!recips || !sk_X509_push(recips, rcert))
38        goto err;
39
40    /*
41     * sk_X509_pop_free will free up recipient STACK and its contents so set
42     * rcert to NULL so it isn't freed up twice.
43     */
44    rcert = NULL;
45
46    /* Open content being encrypted */
47
48    in = BIO_new_file("encr.txt", "r");
49
50    if (!in)
51        goto err;
52
53    /* encrypt content */
54    cms = CMS_encrypt(recips, in, EVP_des_ede3_cbc(), flags);
55
56    if (!cms)
57        goto err;
58
59    out = BIO_new_file("smencr.txt", "w");
60    if (!out)
61        goto err;
62
63    /* Write out S/MIME message */
64    if (!SMIME_write_CMS(out, cms, in, flags))
65        goto err;
66
67    ret = 0;
68
69 err:
70
71    if (ret) {
72        fprintf(stderr, "Error Encrypting Data\n");
73        ERR_print_errors_fp(stderr);
74    }
75
76    if (cms)
77        CMS_ContentInfo_free(cms);
78    if (rcert)
79        X509_free(rcert);
80    if (recips)
81        sk_X509_pop_free(recips, X509_free);
82
83    if (in)
84        BIO_free(in);
85    if (out)
86        BIO_free(out);
87    if (tbio)
88        BIO_free(tbio);
89
90    return ret;
91
92}
93