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.
23 * aes_128_eax_encrypt - AES-128 EAX mode encryption
24 * @key: Key for encryption (16 bytes)
25 * @nonce: Nonce for counter mode
26 * @nonce_len: Nonce length in bytes
27 * @hdr: Header data to be authenticity protected
28 * @hdr_len: Length of the header data bytes
29 * @data: Data to encrypt in-place
30 * @data_len: Length of data in bytes
31 * @tag: 16-byte tag value
32 * Returns: 0 on success, -1 on failure
34 int aes_128_eax_encrypt(const u8 *key, const u8 *nonce, size_t nonce_len,
35 const u8 *hdr, size_t hdr_len,
36 u8 *data, size_t data_len, u8 *tag)
40 u8 nonce_mac[AES_BLOCK_SIZE], hdr_mac[AES_BLOCK_SIZE],
41 data_mac[AES_BLOCK_SIZE];
44 if (nonce_len > data_len)
48 if (hdr_len > buf_len)
52 buf = os_malloc(buf_len);
56 os_memset(buf, 0, 15);
59 os_memcpy(buf + 16, nonce, nonce_len);
60 if (omac1_aes_128(key, buf, 16 + nonce_len, nonce_mac))
64 os_memcpy(buf + 16, hdr, hdr_len);
65 if (omac1_aes_128(key, buf, 16 + hdr_len, hdr_mac))
68 if (aes_128_ctr_encrypt(key, nonce_mac, data, data_len))
71 os_memcpy(buf + 16, data, data_len);
72 if (omac1_aes_128(key, buf, 16 + data_len, data_mac))
75 for (i = 0; i < AES_BLOCK_SIZE; i++)
76 tag[i] = nonce_mac[i] ^ data_mac[i] ^ hdr_mac[i];
87 * aes_128_eax_decrypt - AES-128 EAX mode decryption
88 * @key: Key for decryption (16 bytes)
89 * @nonce: Nonce for counter mode
90 * @nonce_len: Nonce length in bytes
91 * @hdr: Header data to be authenticity protected
92 * @hdr_len: Length of the header data bytes
93 * @data: Data to encrypt in-place
94 * @data_len: Length of data in bytes
95 * @tag: 16-byte tag value
96 * Returns: 0 on success, -1 on failure, -2 if tag does not match
98 int aes_128_eax_decrypt(const u8 *key, const u8 *nonce, size_t nonce_len,
99 const u8 *hdr, size_t hdr_len,
100 u8 *data, size_t data_len, const u8 *tag)
104 u8 nonce_mac[AES_BLOCK_SIZE], hdr_mac[AES_BLOCK_SIZE],
105 data_mac[AES_BLOCK_SIZE];
108 if (nonce_len > data_len)
112 if (hdr_len > buf_len)
116 buf = os_malloc(buf_len);
120 os_memset(buf, 0, 15);
123 os_memcpy(buf + 16, nonce, nonce_len);
124 if (omac1_aes_128(key, buf, 16 + nonce_len, nonce_mac)) {
130 os_memcpy(buf + 16, hdr, hdr_len);
131 if (omac1_aes_128(key, buf, 16 + hdr_len, hdr_mac)) {
137 os_memcpy(buf + 16, data, data_len);
138 if (omac1_aes_128(key, buf, 16 + data_len, data_mac)) {
145 for (i = 0; i < AES_BLOCK_SIZE; i++) {
146 if (tag[i] != (nonce_mac[i] ^ data_mac[i] ^ hdr_mac[i]))
150 return aes_128_ctr_encrypt(key, nonce_mac, data, data_len);