1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright (c) 2021 Marvell.
7 #define KEY_WORD_LEN (ROC_CPT_AES_XCBC_KEY_LENGTH / sizeof(uint32_t))
8 #define KEY_ROUNDS 10 /* (Nr+1)*Nb */
9 #define KEY_SCHEDULE_LEN ((KEY_ROUNDS + 1) * 4) /* (Nr+1)*Nb words */
12 * AES 128 implementation based on NIST FIPS 197 suitable for LittleEndian
13 * https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.197.pdf
16 /* Sbox from NIST FIPS 197 */
17 static uint8_t Sbox[] = {
18 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b,
19 0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0,
20 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93, 0x26,
21 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
22 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2,
23 0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0,
24 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed,
25 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
26 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f,
27 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5,
28 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec,
29 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
30 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14,
31 0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c,
32 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d,
33 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
34 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f,
35 0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e,
36 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11,
37 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
38 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f,
39 0xb0, 0x54, 0xbb, 0x16,
42 /* Substitute a byte with Sbox[byte]. Do it for a word for 4 bytes */
44 sub_word(uint32_t word)
46 word = (Sbox[(word >> 24) & 0xFF] << 24) |
47 (Sbox[(word >> 16) & 0xFF] << 16) |
48 (Sbox[(word >> 8) & 0xFF] << 8) | Sbox[word & 0xFF];
52 /* Rotate a word by one byte */
54 rot_word(uint32_t word)
56 return ((word >> 8) & 0xFFFFFF) | (word << 24);
60 * Multiply with power of 2 and polynomial reduce the result using AES
64 Xtime(uint8_t byte, uint8_t pow)
79 * Multiply a byte with another number such that the result is polynomial
80 * reduced in the GF8 space
83 GF8mul(uint8_t byte, uint32_t mp)
89 mul ^= Xtime(byte, pow);
96 aes_key_expand(const uint8_t *key, uint32_t *ks)
102 memcpy(ks, key, KEY_WORD_LEN * sizeof(uint32_t));
104 while (i < KEY_SCHEDULE_LEN) {
106 if ((i & 0x3) == 0) {
107 temp = rot_word(temp);
108 temp = sub_word(temp);
109 temp ^= (uint32_t)GF8mul(1, 1 << ((i >> 2) - 1));
111 ks[i] = ks[i - 4] ^ temp;
116 /* Shift Rows(columns in state in this implementation) */
118 shift_word(uint8_t *sRc, uint8_t c, int count)
120 /* rotate across non-consecutive locations */
124 sRc[c] = sRc[0x4 + c];
125 sRc[0x4 + c] = sRc[0x8 + c];
126 sRc[0x8 + c] = sRc[0xc + c];
132 /* Mix Columns(rows in state in this implementation) */
134 mix_columns(uint8_t *sRc)
139 for (i = 0; i < 4; i++)
140 new_st[i] = GF8mul(sRc[i], 0x2) ^
141 GF8mul(sRc[(i + 1) & 0x3], 0x3) ^
142 sRc[(i + 2) & 0x3] ^ sRc[(i + 3) & 0x3];
143 for (i = 0; i < 4; i++)
148 cipher(uint8_t *in, uint8_t *out, uint32_t *ks)
150 uint32_t state[KEY_WORD_LEN];
151 unsigned int i, round;
153 memcpy(state, in, sizeof(state));
155 /* AddRoundKey(state, w[0, Nb-1]) // See Sec. 5.1.4 */
156 for (i = 0; i < KEY_WORD_LEN; i++)
159 for (round = 1; round < KEY_ROUNDS; round++) {
160 /* SubBytes(state) // See Sec. 5.1.1 */
161 for (i = 0; i < KEY_WORD_LEN; i++)
162 state[i] = sub_word(state[i]);
164 /* ShiftRows(state) // See Sec. 5.1.2 */
165 for (i = 0; i < KEY_WORD_LEN; i++)
166 shift_word((uint8_t *)state, i, i);
168 /* MixColumns(state) // See Sec. 5.1.3 */
169 for (i = 0; i < KEY_WORD_LEN; i++)
170 mix_columns((uint8_t *)&state[i]);
172 /* AddRoundKey(state, w[round*Nb, (round+1)*Nb-1]) */
173 for (i = 0; i < KEY_WORD_LEN; i++)
174 state[i] ^= ks[round * 4 + i];
177 /* SubBytes(state) */
178 for (i = 0; i < KEY_WORD_LEN; i++)
179 state[i] = sub_word(state[i]);
181 /* ShiftRows(state) */
182 for (i = 0; i < KEY_WORD_LEN; i++)
183 shift_word((uint8_t *)state, i, i);
185 /* AddRoundKey(state, w[Nr*Nb, (Nr+1)*Nb-1]) */
186 for (i = 0; i < KEY_WORD_LEN; i++)
187 state[i] ^= ks[KEY_ROUNDS * 4 + i];
188 memcpy(out, state, KEY_WORD_LEN * sizeof(uint32_t));
192 roc_aes_xcbc_key_derive(const uint8_t *auth_key, uint8_t *derived_key)
194 uint32_t aes_ks[KEY_SCHEDULE_LEN] = {0};
195 uint8_t k1[16] = {[0 ... 15] = 0x01};
196 uint8_t k2[16] = {[0 ... 15] = 0x02};
197 uint8_t k3[16] = {[0 ... 15] = 0x03};
199 aes_key_expand(auth_key, aes_ks);
201 cipher(k1, derived_key, aes_ks);
202 derived_key += sizeof(k1);
204 cipher(k2, derived_key, aes_ks);
205 derived_key += sizeof(k2);
207 cipher(k3, derived_key, aes_ks);