| /* |
| * Copyright 2013-2021 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the Apache License 2.0 (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| /* |
| * Simple AES CCM authenticated encryption with additional data (AEAD) |
| * demonstration program. |
| */ |
| |
| #include <stdio.h> |
| #include <openssl/err.h> |
| #include <openssl/bio.h> |
| #include <openssl/evp.h> |
| #include <openssl/core_names.h> |
| |
| /* AES-CCM test data obtained from NIST public test vectors */ |
| |
| /* AES key */ |
| static const unsigned char ccm_key[] = { |
| 0xce, 0xb0, 0x09, 0xae, 0xa4, 0x45, 0x44, 0x51, 0xfe, 0xad, 0xf0, 0xe6, |
| 0xb3, 0x6f, 0x45, 0x55, 0x5d, 0xd0, 0x47, 0x23, 0xba, 0xa4, 0x48, 0xe8 |
| }; |
| |
| /* Unique nonce to be used for this message */ |
| static const unsigned char ccm_nonce[] = { |
| 0x76, 0x40, 0x43, 0xc4, 0x94, 0x60, 0xb7 |
| }; |
| |
| /* |
| * Example of Additional Authenticated Data (AAD), i.e. unencrypted data |
| * which can be authenticated using the generated Tag value. |
| */ |
| static const unsigned char ccm_adata[] = { |
| 0x6e, 0x80, 0xdd, 0x7f, 0x1b, 0xad, 0xf3, 0xa1, 0xc9, 0xab, 0x25, 0xc7, |
| 0x5f, 0x10, 0xbd, 0xe7, 0x8c, 0x23, 0xfa, 0x0e, 0xb8, 0xf9, 0xaa, 0xa5, |
| 0x3a, 0xde, 0xfb, 0xf4, 0xcb, 0xf7, 0x8f, 0xe4 |
| }; |
| |
| /* Example plaintext to encrypt */ |
| static const unsigned char ccm_pt[] = { |
| 0xc8, 0xd2, 0x75, 0xf9, 0x19, 0xe1, 0x7d, 0x7f, 0xe6, 0x9c, 0x2a, 0x1f, |
| 0x58, 0x93, 0x9d, 0xfe, 0x4d, 0x40, 0x37, 0x91, 0xb5, 0xdf, 0x13, 0x10 |
| }; |
| |
| /* Expected ciphertext value */ |
| static const unsigned char ccm_ct[] = { |
| 0x8a, 0x0f, 0x3d, 0x82, 0x29, 0xe4, 0x8e, 0x74, 0x87, 0xfd, 0x95, 0xa2, |
| 0x8a, 0xd3, 0x92, 0xc8, 0x0b, 0x36, 0x81, 0xd4, 0xfb, 0xc7, 0xbb, 0xfd |
| }; |
| |
| /* Expected AEAD Tag value */ |
| static const unsigned char ccm_tag[] = { |
| 0x2d, 0xd6, 0xef, 0x1c, 0x45, 0xd4, 0xcc, 0xb7, 0x23, 0xdc, 0x07, 0x44, |
| 0x14, 0xdb, 0x50, 0x6d |
| }; |
| |
| /* |
| * A library context and property query can be used to select & filter |
| * algorithm implementations. If they are NULL then the default library |
| * context and properties are used. |
| */ |
| OSSL_LIB_CTX *libctx = NULL; |
| const char *propq = NULL; |
| |
| |
| int aes_ccm_encrypt(void) |
| { |
| int ret = 0; |
| EVP_CIPHER_CTX *ctx; |
| EVP_CIPHER *cipher = NULL; |
| int outlen, tmplen; |
| size_t ccm_nonce_len = sizeof(ccm_nonce); |
| size_t ccm_tag_len = sizeof(ccm_tag); |
| unsigned char outbuf[1024]; |
| unsigned char outtag[16]; |
| OSSL_PARAM params[3] = { |
| OSSL_PARAM_END, OSSL_PARAM_END, OSSL_PARAM_END |
| }; |
| |
| printf("AES CCM Encrypt:\n"); |
| printf("Plaintext:\n"); |
| BIO_dump_fp(stdout, ccm_pt, sizeof(ccm_pt)); |
| |
| /* Create a context for the encrypt operation */ |
| if ((ctx = EVP_CIPHER_CTX_new()) == NULL) |
| goto err; |
| |
| /* Fetch the cipher implementation */ |
| if ((cipher = EVP_CIPHER_fetch(libctx, "AES-192-CCM", propq)) == NULL) |
| goto err; |
| |
| /* Set nonce length if default 96 bits is not appropriate */ |
| params[0] = OSSL_PARAM_construct_size_t(OSSL_CIPHER_PARAM_AEAD_IVLEN, |
| &ccm_nonce_len); |
| /* Set tag length */ |
| params[1] = OSSL_PARAM_construct_octet_string(OSSL_CIPHER_PARAM_AEAD_TAG, |
| NULL, ccm_tag_len); |
| |
| /* |
| * Initialise encrypt operation with the cipher & mode, |
| * nonce length and tag length parameters. |
| */ |
| if (!EVP_EncryptInit_ex2(ctx, cipher, NULL, NULL, params)) |
| goto err; |
| |
| /* Initialise key and nonce */ |
| if (!EVP_EncryptInit_ex(ctx, NULL, NULL, ccm_key, ccm_nonce)) |
| goto err; |
| |
| /* Set plaintext length: only needed if AAD is used */ |
| if (!EVP_EncryptUpdate(ctx, NULL, &outlen, NULL, sizeof(ccm_pt))) |
| goto err; |
| |
| /* Zero or one call to specify any AAD */ |
| if (!EVP_EncryptUpdate(ctx, NULL, &outlen, ccm_adata, sizeof(ccm_adata))) |
| goto err; |
| |
| /* Encrypt plaintext: can only be called once */ |
| if (!EVP_EncryptUpdate(ctx, outbuf, &outlen, ccm_pt, sizeof(ccm_pt))) |
| goto err; |
| |
| /* Output encrypted block */ |
| printf("Ciphertext:\n"); |
| BIO_dump_fp(stdout, outbuf, outlen); |
| |
| /* Finalise: note get no output for CCM */ |
| if (!EVP_EncryptFinal_ex(ctx, NULL, &tmplen)) |
| goto err; |
| |
| /* Get tag */ |
| params[0] = OSSL_PARAM_construct_octet_string(OSSL_CIPHER_PARAM_AEAD_TAG, |
| outtag, ccm_tag_len); |
| params[1] = OSSL_PARAM_construct_end(); |
| |
| if (!EVP_CIPHER_CTX_get_params(ctx, params)) |
| goto err; |
| |
| /* Output tag */ |
| printf("Tag:\n"); |
| BIO_dump_fp(stdout, outtag, ccm_tag_len); |
| |
| ret = 1; |
| err: |
| if (!ret) |
| ERR_print_errors_fp(stderr); |
| |
| EVP_CIPHER_free(cipher); |
| EVP_CIPHER_CTX_free(ctx); |
| |
| return ret; |
| } |
| |
| int aes_ccm_decrypt(void) |
| { |
| int ret = 0; |
| EVP_CIPHER_CTX *ctx; |
| EVP_CIPHER *cipher = NULL; |
| int outlen, rv; |
| unsigned char outbuf[1024]; |
| size_t ccm_nonce_len = sizeof(ccm_nonce); |
| OSSL_PARAM params[3] = { |
| OSSL_PARAM_END, OSSL_PARAM_END, OSSL_PARAM_END |
| }; |
| |
| printf("AES CCM Decrypt:\n"); |
| printf("Ciphertext:\n"); |
| BIO_dump_fp(stdout, ccm_ct, sizeof(ccm_ct)); |
| |
| if ((ctx = EVP_CIPHER_CTX_new()) == NULL) |
| goto err; |
| |
| /* Fetch the cipher implementation */ |
| if ((cipher = EVP_CIPHER_fetch(libctx, "AES-192-CCM", propq)) == NULL) |
| goto err; |
| |
| /* Set nonce length if default 96 bits is not appropriate */ |
| params[0] = OSSL_PARAM_construct_size_t(OSSL_CIPHER_PARAM_AEAD_IVLEN, |
| &ccm_nonce_len); |
| /* Set tag length */ |
| params[1] = OSSL_PARAM_construct_octet_string(OSSL_CIPHER_PARAM_AEAD_TAG, |
| (unsigned char *)ccm_tag, |
| sizeof(ccm_tag)); |
| /* |
| * Initialise decrypt operation with the cipher & mode, |
| * nonce length and expected tag parameters. |
| */ |
| if (!EVP_DecryptInit_ex2(ctx, cipher, NULL, NULL, params)) |
| goto err; |
| |
| /* Specify key and IV */ |
| if (!EVP_DecryptInit_ex(ctx, NULL, NULL, ccm_key, ccm_nonce)) |
| goto err; |
| |
| /* Set ciphertext length: only needed if we have AAD */ |
| if (!EVP_DecryptUpdate(ctx, NULL, &outlen, NULL, sizeof(ccm_ct))) |
| goto err; |
| |
| /* Zero or one call to specify any AAD */ |
| if (!EVP_DecryptUpdate(ctx, NULL, &outlen, ccm_adata, sizeof(ccm_adata))) |
| goto err; |
| |
| /* Decrypt plaintext, verify tag: can only be called once */ |
| rv = EVP_DecryptUpdate(ctx, outbuf, &outlen, ccm_ct, sizeof(ccm_ct)); |
| |
| /* Output decrypted block: if tag verify failed we get nothing */ |
| if (rv > 0) { |
| printf("Tag verify successful!\nPlaintext:\n"); |
| BIO_dump_fp(stdout, outbuf, outlen); |
| } else { |
| printf("Tag verify failed!\nPlaintext not available\n"); |
| goto err; |
| } |
| ret = 1; |
| err: |
| if (!ret) |
| ERR_print_errors_fp(stderr); |
| |
| EVP_CIPHER_free(cipher); |
| EVP_CIPHER_CTX_free(ctx); |
| |
| return ret; |
| } |
| |
| int main(int argc, char **argv) |
| { |
| if (!aes_ccm_encrypt()) |
| return 1; |
| |
| if (!aes_ccm_decrypt()) |
| return 1; |
| |
| return 0; |
| } |