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- // Copyright (c) 2017, Google Inc.
- //
- // Permission to use, copy, modify, and/or distribute this software for any
- // purpose with or without fee is hereby granted, provided that the above
- // copyright notice and this permission notice appear in all copies.
- //
- // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- // SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
-
- #include <openssl/cipher.h>
-
- #include <string.h>
-
- #include <openssl/aes.h>
- #include <openssl/obj.h>
-
- #include "../../crypto/internal.h"
-
- typedef struct {
- AES_KEY ks;
- } EVP_CFB_CTX;
-
- static int aes_cfb_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,
- const uint8_t *iv, int enc) {
- if (key) {
- EVP_CFB_CTX *cfb_ctx = ctx->cipher_data;
- AES_set_encrypt_key(key, ctx->key_len * 8, &cfb_ctx->ks);
- }
-
- return 1;
- }
-
- static int aes_cfb128_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out,
- const uint8_t *in, size_t len) {
- if (!out || !in) {
- return 0;
- }
-
- EVP_CFB_CTX *cfb_ctx = ctx->cipher_data;
- int num = ctx->num;
- AES_cfb128_encrypt(in, out, len, &cfb_ctx->ks, ctx->iv, &num,
- ctx->encrypt ? AES_ENCRYPT : AES_DECRYPT);
- ctx->num = num;
-
- return 1;
- }
-
- static const EVP_CIPHER aes_128_cfb128 = {
- NID_aes_128_cfb128, 1 /* block_size */, 16 /* key_size */,
- 16 /* iv_len */, sizeof(EVP_CFB_CTX), EVP_CIPH_CFB_MODE,
- NULL /* app_data */, aes_cfb_init_key, aes_cfb128_cipher,
- NULL /* cleanup */, NULL /* ctrl */,
- };
-
- const EVP_CIPHER *EVP_aes_128_cfb128(void) { return &aes_128_cfb128; }
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