def encryptFeistel(key, block):
key = key.to_bytes(6, byteorder='big')
lengthDiff = len(key) - len(block)
if lengthDiff > 0:
key = key[lengthDiff:]
keyInt = []
for el in key:
keyInt.append(el)
return operations.xorBlock(keyInt, block)
def encrypt(key, block, encryptFunction):
internalKeys = generateRoundKeys(key)
li = block[:len(block) // 2]
ri = block[len(block) // 2:]
for i in range(16):
oldRi = ri
ri = operations.xorBlock(li, encryptFunction(internalKeys[i], ri))
li = oldRi
return li + ri
def decrypt(key, block, decryptFunction):
internalKeys = generateRoundKeys(key)
internalKeys = internalKeys[::-1]
li = block[:len(block) // 2]
ri = block[len(block) // 2:]
for i in range(16):
oldLi = li
li = operations.xorBlock(ri, decryptFunction(internalKeys[i], li))
ri = oldLi
return li + ri
def encrypt(key, blocks, encryptFunction):
cipherBlocks = []
blockSize = len(blocks[0])
ctr = 0
for i, block in enumerate(blocks):
ctrBlock = ctr.to_bytes(blockSize, byteorder='big')
encryptedCtrBlock = encryptFunction(key[i], ctrBlock)
cipherBlock = operations.xorBlock(encryptedCtrBlock, block)
cipherBlocks.append(cipherBlock)
ctr += 1
return cipherBlocks
def switchKey(key, block):
return operations.xorBlock(key, block)