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 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