diff options
Diffstat (limited to 'src/lilliput-ae-i.c')
| -rw-r--r-- | src/lilliput-ae-i.c | 64 |
1 files changed, 2 insertions, 62 deletions
diff --git a/src/lilliput-ae-i.c b/src/lilliput-ae-i.c index 5d1a630..b1758c9 100644 --- a/src/lilliput-ae-i.c +++ b/src/lilliput-ae-i.c @@ -13,33 +13,6 @@ static const uint8_t _0n[BLOCK_BYTES] = { }; -static void _fill_ad_tweak( - uint8_t prefix, - uint64_t block_nb, - uint8_t tweak[TWEAK_BYTES] -) -{ - /* The 192-bit tweak is filled as follows: - * - * - bits 1-188: block number - * 1- 64: actual 64-bit block number - * 65-188: 0-padding - * - bits 189-192: constant 4-bit prefix - */ - - for (size_t i=0; i<sizeof(block_nb); i++) - { - uint64_t mask = (uint64_t)0xff << 8*i; - uint8_t b = (mask & block_nb) >> 8*i; - - tweak[i] = b; - } - - /* Assume padding bytes have already been memset to 0. */ - - tweak[TWEAK_BYTES-1] |= prefix << 4; -} - static void _fill_msg_tweak( uint8_t prefix, const uint8_t N[NONCE_BYTES], @@ -74,39 +47,6 @@ static void _fill_msg_tweak( tweak[TWEAK_BYTES-1] = prefix << 4 ^ upper_nibble(N[NONCE_BYTES-1]); } -static void _process_associated_data( - const uint8_t key[KEY_BYTES], - size_t A_len, - const uint8_t A[A_len], - uint8_t Auth[BLOCK_BYTES] -) -{ - uint8_t Ek_Ai[BLOCK_BYTES]; - uint8_t tweak[TWEAK_BYTES]; - - memset(tweak, 0, TWEAK_BYTES); - memset(Auth, 0, BLOCK_BYTES); - - size_t l_a = A_len / BLOCK_BYTES; - size_t rest = A_len % BLOCK_BYTES; - - for (size_t i=0; i<l_a; i++) - { - _fill_ad_tweak(0x2, i, tweak); - encrypt(key, tweak, &A[i*BLOCK_BYTES], Ek_Ai); - xor_into(Auth, Ek_Ai); - } - - if (rest != 0) - { - uint8_t A_rest[BLOCK_BYTES]; - pad10(rest, &A[l_a*BLOCK_BYTES], A_rest); - _fill_ad_tweak(0x6, l_a, tweak); - encrypt(key, tweak, A_rest, Ek_Ai); - xor_into(Auth, Ek_Ai); - } -} - static void _encrypt_message( const uint8_t key[KEY_BYTES], size_t M_len, @@ -223,7 +163,7 @@ void lilliput_ae_encrypt( ) { uint8_t auth[BLOCK_BYTES]; - _process_associated_data(key, auth_data_len, auth_data, auth); + process_associated_data(key, auth_data_len, auth_data, auth); uint8_t final[BLOCK_BYTES]; _encrypt_message(key, message_len, message, nonce, ciphertext, final); @@ -243,7 +183,7 @@ bool lilliput_ae_decrypt( ) { uint8_t auth[BLOCK_BYTES]; - _process_associated_data(key, auth_data_len, auth_data, auth); + process_associated_data(key, auth_data_len, auth_data, auth); uint8_t final[BLOCK_BYTES]; _decrypt_message(key, ciphertext_len, ciphertext, nonce, message, final); |