diff options
Diffstat (limited to 'src/add_python/lilliput/ae_mode_1.py')
| -rw-r--r-- | src/add_python/lilliput/ae_mode_1.py | 77 |
1 files changed, 38 insertions, 39 deletions
diff --git a/src/add_python/lilliput/ae_mode_1.py b/src/add_python/lilliput/ae_mode_1.py index c2fdd9e..cc550e8 100644 --- a/src/add_python/lilliput/ae_mode_1.py +++ b/src/add_python/lilliput/ae_mode_1.py @@ -22,12 +22,12 @@ from enum import Enum from .constants import BLOCK_BYTES, NONCE_BYTES from .helpers import ( - ArrayToBlockbytesMatrix, - BlockbytesMatrixToBytes, - BuildAuth, - Padding10LSB, + bytes_to_block_matrix, + block_matrix_to_bytes, + build_auth, + pad10, TagValidationError, - XorState + xor_state ) from . import tbc @@ -36,7 +36,7 @@ TWEAK_BITS = 192 TWEAK_BYTES = TWEAK_BITS//8 -def _LowPart(array, number_bits): +def _low_part(array, number_bits): shifted = 0 for byte in range(0, len(array)): shifted |= (array[byte] << (8 * byte)) @@ -61,13 +61,13 @@ def _LowPart(array, number_bits): class _MessageTweak(Enum): - BLOCK = 0b000 + BLOCK = 0b0000 NO_PADDING = 0b0001 PAD = 0b0100 FINAL = 0b0101 -def _TweakMessage(N, j, padding): +def _tweak_message(N, j, padding): tweak = [0 for byte in range(0, TWEAK_BYTES)] for byte in range(NONCE_BYTES-1, -1, -1): tweak[byte + (TWEAK_BYTES-NONCE_BYTES)] |= (N[byte] & 0xf0) >> 4 @@ -82,90 +82,89 @@ def _TweakMessage(N, j, padding): return tweak -def _TreatMessageEnc(M, N, key): +def _treat_message_enc(M, N, key): checksum = [0 for byte in range(0, BLOCK_BYTES)] l = len(M)//BLOCK_BYTES padding_bytes = len(M)%BLOCK_BYTES - M = ArrayToBlockbytesMatrix(M) + M = bytes_to_block_matrix(M) C = [] for j in range(0, l): - checksum = XorState(checksum, M[j]) - tweak = _TweakMessage(N, j, _MessageTweak.BLOCK) + checksum = xor_state(checksum, M[j]) + tweak = _tweak_message(N, j, _MessageTweak.BLOCK) C.append(tbc.encrypt(tweak, key, M[j])) if padding_bytes == 0: - tweak = _TweakMessage(N, l, _MessageTweak.NO_PADDING) + tweak = _tweak_message(N, l, _MessageTweak.NO_PADDING) Final = tbc.encrypt(tweak, key, checksum) else: - m_padded = Padding10LSB(M[l]) - checksum = XorState(checksum, m_padded) - tweak = _TweakMessage(N, l, _MessageTweak.PAD) + m_padded = pad10(M[l]) + checksum = xor_state(checksum, m_padded) + tweak = _tweak_message(N, l, _MessageTweak.PAD) pad = tbc.encrypt(tweak, key, [0 for byte in range(0, BLOCK_BYTES)]) - lower_part = _LowPart(pad, padding_bytes*8) - C.append(XorState(M[l], lower_part)) - tweak_final = _TweakMessage(N, l+1, _MessageTweak.FINAL) + lower_part = _low_part(pad, padding_bytes*8) + C.append(xor_state(M[l], lower_part)) + tweak_final = _tweak_message(N, l+1, _MessageTweak.FINAL) Final = tbc.encrypt(tweak_final, key, checksum) return (Final, C) -def _TreatMessageDec(C, N, key): +def _treat_message_dec(C, N, key): checksum = [0 for byte in range(0, BLOCK_BYTES)] l = len(C)//BLOCK_BYTES padding_bytes = len(C)%BLOCK_BYTES - C = ArrayToBlockbytesMatrix(C) + C = bytes_to_block_matrix(C) M = [] for j in range(0, l): - tweak = _TweakMessage(N, j, _MessageTweak.BLOCK) + tweak = _tweak_message(N, j, _MessageTweak.BLOCK) M.append(tbc.decrypt(tweak, key, C[j])) - checksum = XorState(checksum, M[j]) + checksum = xor_state(checksum, M[j]) if padding_bytes == 0: - tweak = _TweakMessage(N, l, _MessageTweak.NO_PADDING) + tweak = _tweak_message(N, l, _MessageTweak.NO_PADDING) Final = tbc.encrypt(tweak, key, checksum) else: - tweak = _TweakMessage(N, l, _MessageTweak.PAD) + tweak = _tweak_message(N, l, _MessageTweak.PAD) pad = tbc.encrypt(tweak, key, [0 for byte in range(0, BLOCK_BYTES)]) - lower_part = _LowPart(pad, padding_bytes*8) - M.append(XorState(C[l], lower_part)) + lower_part = _low_part(pad, padding_bytes*8) + M.append(xor_state(C[l], lower_part)) - m_padded = Padding10LSB(M[l]) - checksum = XorState(checksum, m_padded) - tweak_final = _TweakMessage(N, l+1, _MessageTweak.FINAL) + m_padded = pad10(M[l]) + checksum = xor_state(checksum, m_padded) + tweak_final = _tweak_message(N, l+1, _MessageTweak.FINAL) Final = tbc.encrypt(tweak_final, key, checksum) return (Final, M) -################################################################################ def encrypt(A, M, N, key): K = list(key) - Auth = BuildAuth(TWEAK_BITS, A, K) - (Final, C) = _TreatMessageEnc(M, N, K) - tag = XorState(Auth, Final) + Auth = build_auth(TWEAK_BITS, A, K) + (Final, C) = _treat_message_enc(M, N, K) + tag = xor_state(Auth, Final) - return BlockbytesMatrixToBytes(C), bytes(tag) + return block_matrix_to_bytes(C), bytes(tag) def decrypt(A, C, N, tag, key): K = list(key) tag = list(tag) - Auth = BuildAuth(TWEAK_BITS, A, K) - (Final, M) = _TreatMessageDec(C, N, K) - tag2 = XorState(Auth, Final) + Auth = build_auth(TWEAK_BITS, A, K) + (Final, M) = _treat_message_dec(C, N, K) + tag2 = xor_state(Auth, Final) if tag != tag2: raise TagValidationError(tag, tag2) - return BlockbytesMatrixToBytes(M) + return block_matrix_to_bytes(M) |