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git.ipfire.org Git - thirdparty/hostap.git/blob - src/crypto/aes-wrap.c
2 * AES Key Wrap Algorithm (128-bit KEK) (RFC3394)
4 * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * Alternatively, this software may be distributed under the terms of BSD
13 * See README and COPYING for more details.
22 * aes_wrap - Wrap keys with AES Key Wrap Algorithm (128-bit KEK) (RFC3394)
23 * @kek: 16-octet Key encryption key (KEK)
24 * @n: Length of the plaintext key in 64-bit units; e.g., 2 = 128-bit = 16
26 * @plain: Plaintext key to be wrapped, n * 64 bits
27 * @cipher: Wrapped key, (n + 1) * 64 bits
28 * Returns: 0 on success, -1 on failure
30 int aes_wrap(const u8
*kek
, int n
, const u8
*plain
, u8
*cipher
)
39 /* 1) Initialize variables. */
40 os_memset(a
, 0xa6, 8);
41 os_memcpy(r
, plain
, 8 * n
);
43 ctx
= aes_encrypt_init(kek
, 16);
47 /* 2) Calculate intermediate values.
50 * B = AES(K, A | R[i])
51 * A = MSB(64, B) ^ t where t = (n*j)+i
54 for (j
= 0; j
<= 5; j
++) {
56 for (i
= 1; i
<= n
; i
++) {
58 os_memcpy(b
+ 8, r
, 8);
59 aes_encrypt(ctx
, b
, b
);
62 os_memcpy(r
, b
+ 8, 8);
66 aes_encrypt_deinit(ctx
);
68 /* 3) Output the results.
70 * These are already in @cipher due to the location of temporary