merge setkey_enc* functions
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
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97b31d8ca3
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1 changed files with 35 additions and 65 deletions
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@ -160,9 +160,6 @@ void mbedtls_aesce_inverse_key(unsigned char *invkey,
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}
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static uint8_t const rcon[] = { 0x01, 0x02, 0x04, 0x08, 0x10,
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0x20, 0x40, 0x80, 0x1b, 0x36 };
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static inline uint32_t aes_rot_word(uint32_t word)
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{
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return (word << (32 - 8)) | (word >> 8);
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@ -180,76 +177,48 @@ static inline uint32_t aes_sub_word(uint32_t in)
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}
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/*
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* Key expansion, 128-bit case
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* Key expansion function
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*/
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static void aesce_setkey_enc_128(unsigned char *rk,
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const unsigned char *key)
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static void aesce_setkey_enc(unsigned char *rk,
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const unsigned char *key,
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const size_t key_bit_length)
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{
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uint32_t *rki;
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uint32_t *rko;
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uint32_t *rk_u32 = (uint32_t *) rk;
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const uint32_t key_len_in_words = key_bit_length / 32;
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const uint32_t key_len_in_bytes = key_bit_length / 8;
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static uint8_t const rcon[] = { 0x01, 0x02, 0x04, 0x08, 0x10,
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0x20, 0x40, 0x80, 0x1b, 0x36 };
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const uint32_t rounds =
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key_bit_length == 128 ? sizeof(rcon) : key_bit_length == 192 ? 8 : 7;
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memcpy(rk, key, (128 / 8));
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memcpy(rk, key, key_len_in_bytes);
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for (size_t i = 0; i < sizeof(rcon); i++) {
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rki = rk_u32 + i * (128 / 32);
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rko = rki + (128 / 32);
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rko[0] = aes_rot_word(aes_sub_word(rki[(128 / 32) - 1])) ^ rcon[i] ^ rki[0];
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rko[1] = rko[0] ^ rki[1];
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rko[2] = rko[1] ^ rki[2];
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rko[3] = rko[2] ^ rki[3];
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}
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}
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/*
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* Key expansion, 192-bit case
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*/
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static void aesce_setkey_enc_192(unsigned char *rk,
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const unsigned char *key)
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{
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uint32_t *rki;
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uint32_t *rko;
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uint32_t *rk_u32 = (uint32_t *) rk;
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memcpy(rk, key, (192 / 8));
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for (size_t i = 0; i < 8; i++) {
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rki = rk_u32 + i * (192 / 32);
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rko = rki + (192 / 32);
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rko[0] = aes_rot_word(aes_sub_word(rki[(192 / 32) - 1])) ^ rcon[i] ^ rki[0];
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for (size_t i = 0; i < rounds; i++) {
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rki = rk_u32 + i * key_len_in_words;
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rko = rki + key_len_in_words;
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rko[0] = aes_rot_word(aes_sub_word(rki[key_len_in_words - 1]));
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rko[0] ^= rcon[i] ^ rki[0];
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rko[1] = rko[0] ^ rki[1];
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rko[2] = rko[1] ^ rki[2];
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rko[3] = rko[2] ^ rki[3];
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switch (key_bit_length) {
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case 192:
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if (i < 7) {
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rko[4] = rko[3] ^ rki[4];
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rko[5] = rko[4] ^ rki[5];
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}
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}
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}
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/*
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* Key expansion, 256-bit case
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*/
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static void aesce_setkey_enc_256(unsigned char *rk,
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const unsigned char *key)
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{
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uint32_t *rki;
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uint32_t *rko;
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uint32_t *rk_u32 = (uint32_t *) rk;
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memcpy(rk, key, (256 / 8));
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for (size_t i = 0; i < 7; i++) {
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rki = rk_u32 + i * (256 / 32);
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rko = rki + (256 / 32);
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rko[0] = aes_rot_word(aes_sub_word(rki[(256 / 32) - 1])) ^ rcon[i] ^ rki[0];
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rko[1] = rko[0] ^ rki[1];
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rko[2] = rko[1] ^ rki[2];
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rko[3] = rko[2] ^ rki[3];
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break;
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case 256:
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if (i < 6) {
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rko[4] = aes_sub_word(rko[3]) ^ rki[4];
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rko[5] = rko[4] ^ rki[5];
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rko[6] = rko[5] ^ rki[6];
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rko[7] = rko[6] ^ rki[7];
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}
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break;
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}
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}
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}
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@ -261,9 +230,10 @@ int mbedtls_aesce_setkey_enc(unsigned char *rk,
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size_t bits)
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{
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switch (bits) {
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case 128: aesce_setkey_enc_128(rk, key); break;
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case 192: aesce_setkey_enc_192(rk, key); break;
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case 256: aesce_setkey_enc_256(rk, key); break;
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case 128:
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case 192:
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case 256:
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aesce_setkey_enc(rk, key, bits); break;
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default: return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
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}
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