2 * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 FILE_LICENCE ( GPL2_OR_LATER );
24 #include <ipxe/crypto.h>
28 * Wrap a key or other data using AES Key Wrap (RFC 3394)
30 * @v kek Key Encryption Key, 16 bytes
31 * @v src Data to encrypt
32 * @v nblk Number of 8-byte blocks in @a data
33 * @ret dest Encrypted data (8 bytes longer than input)
35 * The algorithm is implemented such that @a src and @a dest may point
38 int aes_wrap ( const void *kek, const void *src, void *dest, int nblk )
44 void *aes_ctx = malloc ( AES_CTX_SIZE );
49 cipher_setkey ( &aes_algorithm, aes_ctx, kek, 16 );
52 memset ( A, 0xA6, 8 );
53 memmove ( dest + 8, src, nblk * 8 );
56 for ( j = 0; j < 6; j++ ) {
58 for ( i = 1; i <= nblk; i++ ) {
60 memcpy ( B + 8, R, 8 );
61 cipher_encrypt ( &aes_algorithm, aes_ctx, B, B, 16 );
63 A[7] ^= ( nblk * j ) + i;
64 memcpy ( R, B + 8, 8 );
74 * Unwrap a key or other data using AES Key Wrap (RFC 3394)
76 * @v kek Key Encryption Key, 16 bytes
77 * @v src Data to decrypt
78 * @v nblk Number of 8-byte blocks in @e plaintext key
79 * @ret dest Decrypted data (8 bytes shorter than input)
80 * @ret rc Zero on success, nonzero on IV mismatch
82 * The algorithm is implemented such that @a src and @a dest may point
85 int aes_unwrap ( const void *kek, const void *src, void *dest, int nblk )
90 void *aes_ctx = malloc ( AES_CTX_SIZE );
95 cipher_setkey ( &aes_algorithm, aes_ctx, kek, 16 );
99 memmove ( dest, src + 8, nblk * 8 );
102 for ( j = 5; j >= 0; j-- ) {
103 R = dest + ( nblk - 1 ) * 8;
104 for ( i = nblk; i >= 1; i-- ) {
106 memcpy ( B + 8, R, 8 );
107 B[7] ^= ( nblk * j ) + i;
108 cipher_decrypt ( &aes_algorithm, aes_ctx, B, B, 16 );
110 memcpy ( R, B + 8, 8 );
118 for ( i = 0; i < 8; i++ ) {