xref: /openssl/demos/cms/cms_dec.c (revision 86db9588)
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 decryption 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 *rcert = NULL;
19     EVP_PKEY *rkey = NULL;
20     CMS_ContentInfo *cms = NULL;
21     int ret = EXIT_FAILURE;
22 
23     OpenSSL_add_all_algorithms();
24     ERR_load_crypto_strings();
25 
26     /* Read in recipient certificate and private key */
27     tbio = BIO_new_file("signer.pem", "r");
28 
29     if (!tbio)
30         goto err;
31 
32     rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
33 
34     if (BIO_reset(tbio) < 0)
35         goto err;
36 
37     rkey = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL);
38 
39     if (!rcert || !rkey)
40         goto err;
41 
42     /* Open S/MIME message to decrypt */
43 
44     in = BIO_new_file("smencr.txt", "r");
45 
46     if (!in)
47         goto err;
48 
49     /* Parse message */
50     cms = SMIME_read_CMS(in, NULL);
51 
52     if (!cms)
53         goto err;
54 
55     out = BIO_new_file("decout.txt", "w");
56     if (!out)
57         goto err;
58 
59     /* Decrypt S/MIME message */
60     if (!CMS_decrypt(cms, rkey, rcert, NULL, out, 0))
61         goto err;
62 
63     printf("Decryption Successful\n");
64 
65     ret = EXIT_SUCCESS;
66 
67  err:
68     if (ret != EXIT_SUCCESS) {
69         fprintf(stderr, "Error Decrypting Data\n");
70         ERR_print_errors_fp(stderr);
71     }
72 
73     CMS_ContentInfo_free(cms);
74     X509_free(rcert);
75     EVP_PKEY_free(rkey);
76     BIO_free(in);
77     BIO_free(out);
78     BIO_free(tbio);
79     return ret;
80 }
81