1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*
3 * Copyright (c) 2014-2019, Linaro Limited
4 */
5
get_des2_key(const uint8_t ** key,size_t * key_len,uint8_t * tmp)6 static inline void get_des2_key(const uint8_t **key, size_t *key_len,
7 uint8_t *tmp)
8 {
9 if (*key_len == 16) {
10 /*
11 * This corresponds to a 2DES key. The 2DES encryption
12 * algorithm is similar to 3DES. Both perform and
13 * encryption step, then a decryption step, followed
14 * by another encryption step (EDE). However 2DES uses
15 * the same key for both of the encryption (E) steps.
16 */
17 memcpy(tmp, *key, 16);
18 memcpy(tmp + 16, *key, 8);
19 *key = tmp;
20 *key_len = 24;
21 }
22 }
23