def encrypt(self, plaintext):
ptBlocks = self.getBlocks(plaintext)
ciphertext = b''
prev = self.IV
for block in ptBlocks:
toEnc = xor(prev, block)
cipherBlock = self.ECB.encrypt(bytes(toEnc))
prev = cipherBlock
#print(cipherBlock)
ciphertext += cipherBlock
return ciphertext
def decrypt(self, ciphertext):
#Split the ciphertext into blocks
ctBlocks = self.getBlocks(ciphertext)
plaintext = b''
prev = self.IV
for block in ctBlocks:
#Decrypt the ciphertext block and xor it with the IV/Previous block
plainBlock = bytes(xor(prev, self.ECB.decrypt(block)))
prev = block
plaintext += plainBlock
return plaintext
def main():
ans = "0b3637272a2b2e63622c2e69692a23693a2a3c6324202d623d63343c2a26226324272765272"
ans += "a282b2f20430a652e2c652a3124333a653e2b2027630c692b20283165286326302e27282f"
ans = bytearray.fromhex(ans)
inputStr = "Burning 'em, if you ain't quick and nimble\n"
inputStr += "I go crazy when I hear a cymbal"
key = "ICE"
inputArr = bytearray(inputStr.encode())
keyArr = bytearray(key.encode())
res = xor(inputArr,keyArr)
print(binascii.hexlify(res))
validate(res, ans)
def main():
ans = "0b3637272a2b2e63622c2e69692a23693a2a3c6324202d623d63343c2a26226324272765272"
ans += "a282b2f20430a652e2c652a3124333a653e2b2027630c692b20283165286326302e27282f"
ans = bytearray.fromhex(ans)
inputStr = "Burning 'em, if you ain't quick and nimble\n"
inputStr += "I go crazy when I hear a cymbal"
key = "ICE"
inputArr = bytearray(inputStr.encode())
keyArr = bytearray(key.encode())
res = xor(inputArr, keyArr)
print(binascii.hexlify(res))
validate(res, ans)
def main():
inputFile = "assets/Set1/inputC6.txt"
inputStr = ''
newHam = 0
bestHam = 10000
keyLen = 0
key = None
res = None
#Read in the entire file and concatenate it to a string.
for line in open(inputFile,"r"):
inputStr += line.rstrip()
#Decode the input from base 64 and convert it to a byte string.
decodedStr = bytearray(base64.b64decode(inputStr))
#print(inputStr)
#print(base64.b64decode(inputStr))
for i in range(1,40):
newHam = avgHamming(decodedStr,i, 10) / i
#print(i,"hamming dist",newHam)
if(newHam < bestHam):
bestHam = newHam
keyLen = i
#Create the array that will store the key
key = bytearray(keyLen)
for i in range(0,keyLen):
encChunk = everyNth(decodedStr,keyLen, i)
(k,d,r) = xorBruteForce1(encChunk)
key[i] = k
print("Key:", key.decode())
print("\n\nDeciphered text:")
res = xor(decodedStr,key)
#print(res)
print(res.decode("ascii"))
def calcHamming(arr1, arr2):
numBits = 0
resArr = xor(arr1,arr2)
for j in range(0,len(arr1)):
numBits += bin(resArr[j]).count('1')
return numBits