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 /*
11 * S/MIME detached data decrypt example: rarely done but should the need
12 * arise this is an example....
13 */
14 #include <openssl/pem.h>
15 #include <openssl/cms.h>
16 #include <openssl/err.h>
17
main(int argc,char ** argv)18 int main(int argc, char **argv)
19 {
20 BIO *in = NULL, *out = NULL, *tbio = NULL, *dcont = NULL;
21 X509 *rcert = NULL;
22 EVP_PKEY *rkey = NULL;
23 CMS_ContentInfo *cms = NULL;
24 int ret = EXIT_FAILURE;
25
26 OpenSSL_add_all_algorithms();
27 ERR_load_crypto_strings();
28
29 /* Read in recipient certificate and private key */
30 tbio = BIO_new_file("signer.pem", "r");
31
32 if (!tbio)
33 goto err;
34
35 rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
36
37 if (BIO_reset(tbio) < 0)
38 goto err;
39
40 rkey = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL);
41
42 if (!rcert || !rkey)
43 goto err;
44
45 /* Open PEM file containing enveloped data */
46
47 in = BIO_new_file("smencr.pem", "r");
48
49 if (!in)
50 goto err;
51
52 /* Parse PEM content */
53 cms = PEM_read_bio_CMS(in, NULL, 0, NULL);
54
55 if (!cms)
56 goto err;
57
58 /* Open file containing detached content */
59 dcont = BIO_new_file("smencr.out", "rb");
60
61 if (!in)
62 goto err;
63
64 out = BIO_new_file("encrout.txt", "w");
65 if (!out)
66 goto err;
67
68 /* Decrypt S/MIME message */
69 if (!CMS_decrypt(cms, rkey, rcert, dcont, out, 0))
70 goto err;
71
72 ret = EXIT_SUCCESS;
73
74 err:
75
76 if (ret != EXIT_SUCCESS) {
77 fprintf(stderr, "Error Decrypting Data\n");
78 ERR_print_errors_fp(stderr);
79 }
80
81 CMS_ContentInfo_free(cms);
82 X509_free(rcert);
83 EVP_PKEY_free(rkey);
84 BIO_free(in);
85 BIO_free(out);
86 BIO_free(tbio);
87 BIO_free(dcont);
88 return ret;
89 }
90
