1 /* 2 * Copyright 2007-2023 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 encrypt example */ 11 #include <openssl/pem.h> 12 #include <openssl/pkcs7.h> 13 #include <openssl/err.h> 14 15 int main(int argc, char **argv) 16 { 17 BIO *in = NULL, *out = NULL, *tbio = NULL; 18 X509 *rcert = NULL; 19 STACK_OF(X509) *recips = NULL; 20 PKCS7 *p7 = NULL; 21 int ret = EXIT_FAILURE; 22 23 /* 24 * for streaming set PKCS7_STREAM 25 */ 26 int flags = PKCS7_STREAM; 27 28 OpenSSL_add_all_algorithms(); 29 ERR_load_crypto_strings(); 30 31 /* Read in recipient certificate */ 32 tbio = BIO_new_file("signer.pem", "r"); 33 34 if (!tbio) 35 goto err; 36 37 rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL); 38 39 if (!rcert) 40 goto err; 41 42 /* Create recipient STACK and add recipient cert to it */ 43 recips = sk_X509_new_null(); 44 45 if (!recips || !sk_X509_push(recips, rcert)) 46 goto err; 47 48 /* 49 * OSSL_STACK_OF_X509_free() will free up recipient STACK and its contents 50 * so set rcert to NULL so it isn't freed up twice. 51 */ 52 rcert = NULL; 53 54 /* Open content being encrypted */ 55 56 in = BIO_new_file("encr.txt", "r"); 57 58 if (!in) 59 goto err; 60 61 /* encrypt content */ 62 p7 = PKCS7_encrypt(recips, in, EVP_des_ede3_cbc(), flags); 63 64 if (!p7) 65 goto err; 66 67 out = BIO_new_file("smencr.txt", "w"); 68 if (!out) 69 goto err; 70 71 /* Write out S/MIME message */ 72 if (!SMIME_write_PKCS7(out, p7, in, flags)) 73 goto err; 74 75 printf("Success\n"); 76 77 ret = EXIT_SUCCESS; 78 err: 79 if (ret != EXIT_SUCCESS) { 80 fprintf(stderr, "Error Encrypting Data\n"); 81 ERR_print_errors_fp(stderr); 82 } 83 PKCS7_free(p7); 84 X509_free(rcert); 85 OSSL_STACK_OF_X509_free(recips); 86 BIO_free(in); 87 BIO_free(out); 88 BIO_free(tbio); 89 return ret; 90 } 91