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
aes_cfb_init_key(EVP_CIPHER_CTX * ctx,const uint8_t * key,const uint8_t * iv,int enc)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
aes_cfb128_cipher(EVP_CIPHER_CTX * ctx,uint8_t * out,const uint8_t * in,size_t len)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
EVP_aes_128_cfb128(void)60 const EVP_CIPHER *EVP_aes_128_cfb128(void) { return &aes_128_cfb128; }
61