[implem-python] Retrait de A_BITS/M_BITS (2/2)

1 files changed, 21 insertions, 35 deletions

diff --git a/python/lilliput_ae_2.py b/python/lilliput_ae_2.py
index 164c3df..720e1aa 100644
--- a/python/lilliput_ae_2.py
+++ b/python/lilliput_ae_2.py
@@ -13,20 +13,16 @@ from helpers import (
 )
 
 
-BLOCK_BITS = 128
 KEY_BITS = 128
 TWEAK_BITS = 128
 TWEAKEY_BITS = KEY_BITS + TWEAK_BITS
 LANE_BITS = 64
 LANES = int((TWEAKEY_BITS) / LANE_BITS)
 
-BLOCK_BYTES = int(BLOCK_BITS / 8)
 KEY_BYTES = int(KEY_BITS / 8)
 TWEAK_BYTES = int(TWEAK_BITS / 8)
 TWEAKEY_BYTES = int(TWEAKEY_BITS / 8)
 
-M_BITS = BLOCK_BITS
-
 
 def InitParameters(key_bits) :
     global KEY_BITS
@@ -68,14 +64,14 @@ def LowPart(array, number_bits) :
 
 ################################################################################
 
-def TweakTag(j, padded = 0) :
+def TweakTag(j, padded):
         tweak = [0 for byte in range(0,  TWEAK_BYTES)]
 
         tweak[TWEAK_BYTES - 1] |= ((j >> 120) & 0xf)
         for byte in range(TWEAK_BYTES - 2, -1, -1) :
             tweak[byte] = (j >> (8 * byte)) & 0xff
 
-        if padded == 1 :
+        if padded:
             tweak[TWEAK_BYTES - 1] |= 0x40
 
         return tweak
@@ -103,22 +99,20 @@ def AddTagJ(tag, j) :
 
 
 def MesssageAuthTag(M, N, Auth, key) :
-    l = int(M_BITS / BLOCK_BITS)
-    if int(M_BITS % BLOCK_BITS) > 0 :
-        will_padd = 1
-    else :
-        will_padd = 0
+    l = len(M)//BLOCK_BYTES
+    padding_bytes = len(M)%BLOCK_BYTES
 
     tag = list(Auth)
+    M = ArrayToBlockbytesMatrix(M)
 
     for j in range(0, l) :
-        tweak = TweakTag(j, padded = 0)
+        tweak = TweakTag(j, False)
         encryption = ltbc.LilliputTBCEnc(tweak, key, M[j])
         tag = XorState(tag, encryption)
 
-    if will_padd == 1 :
-        tweak = TweakTag(l, padded = 1)
-        m_padded = Padding10LSB(M[l], M_BITS % BLOCK_BITS)
+    if padding_bytes > 0 :
+        tweak = TweakTag(l, True)
+        m_padded = Padding10LSB(M[l], 8*padding_bytes)
         encryption = ltbc.LilliputTBCEnc(tweak, key, m_padded)
         tag = XorState(tag, encryption)
 
@@ -130,25 +124,23 @@ def MesssageAuthTag(M, N, Auth, key) :
 
 
 def MessageEncryption(M, N, tag, key) :
-    l = int(M_BITS / BLOCK_BITS)
-    if int(M_BITS % BLOCK_BITS) > 0 :
-        will_padd = 1
-    else :
-        will_padd = 0
+    l = len(M)//BLOCK_BYTES
+    padding_bytes = len(M)%BLOCK_BYTES
 
-    C = [[0 for byte in range(0, 16)] for j in range(0, l + will_padd)]
+    M = ArrayToBlockbytesMatrix(M)
+    C = []
 
     for j in range(0, l) :
         tweak = AddTagJ(tag, j)
         padded_nounce = list(N) + [0x00]
         encryption = ltbc.LilliputTBCEnc(tweak, key, padded_nounce)
-        C[j] = XorState(M[j], encryption)
+        C.append(XorState(M[j], encryption))
 
-    if will_padd :
+    if padding_bytes > 0:
         tweak = AddTagJ(tag, l)
         padded_nounce = list(N) + [0x00]
         encryption = ltbc.LilliputTBCEnc(tweak, key, padded_nounce)
-        C[l] = XorState(M[l], encryption)
+        C.append(XorState(M[l], encryption))
 
     return C
 
@@ -156,10 +148,6 @@ def MessageEncryption(M, N, tag, key) :
 def SCT2Enc(A, M, N, key) :
     InitParameters(len(key)*8)
 
-    global M_BITS
-    M_BITS = len(M)*8
-
-    M = ArrayToBlockbytesMatrix(M)
     K = list(key)
 
     Auth = BuildAuth(TWEAK_BITS, A, K)
@@ -172,15 +160,13 @@ def SCT2Enc(A, M, N, key) :
 def SCT2Dec(A, C, N, tag, key) :
     InitParameters(len(key)*8)
 
-    global M_BITS
-    M_BITS = len(C)*8
-
-    C = ArrayToBlockbytesMatrix(C)
     K = list(key)
 
-    M = MessageEncryption(C, N, tag, K)
+    M = BlockbytesMatrixToBytes(
+        MessageEncryption(C, N, tag, K)
+    )
     Auth = BuildAuth(TWEAK_BITS, A, K)
     tag2 = MesssageAuthTag(M, N, Auth, K)
 
-    if(tag == tag2) :
-        return BlockbytesMatrixToBytes(M)
+    if tag == tag2:
+        return M