3 * Copyright (c) 2013 Cozybit, Inc.
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
17 static const u8 zero[AES_BLOCK_SIZE];
20 static void dbl(u8 *pad)
24 carry = pad[0] & 0x80;
25 for (i = 0; i < AES_BLOCK_SIZE - 1; i++)
26 pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
27 pad[AES_BLOCK_SIZE - 1] <<= 1;
29 pad[AES_BLOCK_SIZE - 1] ^= 0x87;
33 static void xor(u8 *a, const u8 *b)
37 for (i = 0; i < AES_BLOCK_SIZE; i++)
42 static void xorend(u8 *a, int alen, const u8 *b, int blen)
49 for (i = 0; i < blen; i++)
50 a[alen - blen + i] ^= b[i];
54 static void pad_block(u8 *pad, const u8 *addr, size_t len)
56 os_memset(pad, 0, AES_BLOCK_SIZE);
57 os_memcpy(pad, addr, len);
59 if (len < AES_BLOCK_SIZE)
64 static int aes_s2v(const u8 *key, size_t key_len,
65 size_t num_elem, const u8 *addr[], size_t *len, u8 *mac)
67 u8 tmp[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
75 os_memcpy(tmp, zero, sizeof(zero));
76 tmp[AES_BLOCK_SIZE - 1] = 1;
78 data_len[0] = sizeof(tmp);
79 return omac1_aes_vector(key, key_len, 1, data, data_len, mac);
83 data_len[0] = sizeof(zero);
84 ret = omac1_aes_vector(key, key_len, 1, data, data_len, tmp);
88 for (i = 0; i < num_elem - 1; i++) {
89 ret = omac1_aes_vector(key, key_len, 1, &addr[i], &len[i],
97 if (len[i] >= AES_BLOCK_SIZE) {
98 buf = os_memdup(addr[i], len[i]);
102 xorend(buf, len[i], tmp, AES_BLOCK_SIZE);
104 ret = omac1_aes_vector(key, key_len, 1, data, &len[i], mac);
105 bin_clear_free(buf, len[i]);
110 pad_block(tmp2, addr[i], len[i]);
114 data_len[0] = sizeof(tmp);
115 return omac1_aes_vector(key, key_len, 1, data, data_len, mac);
119 int aes_siv_encrypt(const u8 *key, size_t key_len,
120 const u8 *pw, size_t pwlen,
121 size_t num_elem, const u8 *addr[], const size_t *len,
127 u8 v[AES_BLOCK_SIZE];
131 if (num_elem > ARRAY_SIZE(_addr) - 1 ||
132 (key_len != 32 && key_len != 48 && key_len != 64))
139 for (i = 0; i < num_elem; i++) {
143 _addr[num_elem] = pw;
144 _len[num_elem] = pwlen;
146 if (aes_s2v(k1, key_len, num_elem + 1, _addr, _len, v))
150 crypt_pw = out + AES_BLOCK_SIZE;
152 os_memcpy(iv, v, AES_BLOCK_SIZE);
153 os_memcpy(crypt_pw, pw, pwlen);
155 /* zero out 63rd and 31st bits of ctr (from right) */
158 return aes_ctr_encrypt(k2, key_len, v, crypt_pw, pwlen);
162 int aes_siv_decrypt(const u8 *key, size_t key_len,
163 const u8 *iv_crypt, size_t iv_c_len,
164 size_t num_elem, const u8 *addr[], const size_t *len,
173 u8 iv[AES_BLOCK_SIZE];
174 u8 check[AES_BLOCK_SIZE];
176 if (iv_c_len < AES_BLOCK_SIZE || num_elem > ARRAY_SIZE(_addr) - 1 ||
177 (key_len != 32 && key_len != 48 && key_len != 64))
179 crypt_len = iv_c_len - AES_BLOCK_SIZE;
184 for (i = 0; i < num_elem; i++) {
188 _addr[num_elem] = out;
189 _len[num_elem] = crypt_len;
191 os_memcpy(iv, iv_crypt, AES_BLOCK_SIZE);
192 os_memcpy(out, iv_crypt + AES_BLOCK_SIZE, crypt_len);
197 ret = aes_ctr_encrypt(k2, key_len, iv, out, crypt_len);
201 ret = aes_s2v(k1, key_len, num_elem + 1, _addr, _len, check);
204 if (os_memcmp(check, iv_crypt, AES_BLOCK_SIZE) == 0)