1 // Copyright (c) 2017, Google Inc. 2 // 3 // Permission to use, copy, modify, and/or distribute this software for any 4 // purpose with or without fee is hereby granted, provided that the above 5 // copyright notice and this permission notice appear in all copies. 6 // 7 // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 8 // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9 // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 10 // SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11 // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 12 // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 13 // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ 14 15 #include <openssl/cipher.h> 16 17 #include <string.h> 18 19 #include <openssl/aes.h> 20 #include <openssl/obj.h> 21 22 #include "../../crypto/internal.h" 23 24 typedef struct { 25 AES_KEY ks; 26 } EVP_CFB_CTX; 27 28 static int aes_cfb_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key, 29 const uint8_t *iv, int enc) { 30 if (key) { 31 EVP_CFB_CTX *cfb_ctx = ctx->cipher_data; 32 AES_set_encrypt_key(key, ctx->key_len * 8, &cfb_ctx->ks); 33 } 34 35 return 1; 36 } 37 38 static int aes_cfb128_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out, 39 const uint8_t *in, size_t len) { 40 if (!out || !in) { 41 return 0; 42 } 43 44 EVP_CFB_CTX *cfb_ctx = ctx->cipher_data; 45 int num = ctx->num; 46 AES_cfb128_encrypt(in, out, len, &cfb_ctx->ks, ctx->iv, &num, 47 ctx->encrypt ? AES_ENCRYPT : AES_DECRYPT); 48 ctx->num = num; 49 50 return 1; 51 } 52 53 static const EVP_CIPHER aes_128_cfb128 = { 54 NID_aes_128_cfb128, 1 /* block_size */, 16 /* key_size */, 55 16 /* iv_len */, sizeof(EVP_CFB_CTX), EVP_CIPH_CFB_MODE, 56 NULL /* app_data */, aes_cfb_init_key, aes_cfb128_cipher, 57 NULL /* cleanup */, NULL /* ctrl */, 58 }; 59 60 const EVP_CIPHER *EVP_aes_128_cfb128(void) { return &aes_128_cfb128; } 61
