def hmac(ipBytes, key, hashFunc, blockSize, outputSize):
opad = bytes(('\x5c' * blockSize).encode('latin1'))
ipad = bytes(('\x36' * blockSize).encode('latin1'))
if len(key) > blockSize:
h = hashFunc.copy()
h.update(key)
key = h.digest()
keyPad = '\x00' * (blockSize - len(key))
keyPad = bytes(keyPad.encode('latin1'))
key = key + keyPad
o_key_pad = ENC.fixedXor(key, opad)
i_key_pad = ENC.fixedXor(key, ipad)
h = hashFunc.copy()
h.update(i_key_pad + ipBytes)
tempHash = h.digest()
h = hashFunc.copy()
h.update(o_key_pad + tempHash)
finalHash = h.digest()
return finalHash
def AES_CTR(ipBytes, key, nonce):
blockSize = 16
nonce = get64BitLittleEndianBytes(nonce)
noOfBlocks = math.ceil(len(ipBytes) / blockSize)
opBytes = bytes(''.encode('utf-8'))
for i in range(noOfBlocks):
ctr = get64BitLittleEndianBytes(i)
ipToAes = nonce + ctr
encryptedCtr = AES_ECB.AESencrypt(ipToAes, key)
if i == noOfBlocks - 1:
ipBytesForXor = ipBytes[i * blockSize:]
op = ENC.fixedXor(encryptedCtr[:len(ipBytesForXor)], ipBytesForXor)
opBytes += op
else:
op = ENC.fixedXor(encryptedCtr,
ipBytes[i * blockSize:(i + 1) * blockSize])
opBytes += op
return opBytes
def AES_CBCencrypt(ptByteArray, key, IV):
prevCt = IV
ct = []
for i in range(len(ptByteArray) // 16):
ptInput = xorEnc.fixedXor(ptByteArray[i * 16:(i + 1) * 16], prevCt)
newCtBlock = AES_ECB.AESencrypt(ptInput, key)
for j in range(len(newCtBlock)):
ct.append(newCtBlock[j])
prevCt = newCtBlock
ct = bytes(ct)
return ct
def AES_CBCdecrypt(ctByteArray, key, IV):
pt = []
for i in range(len(ctByteArray) // 16):
ctInputBlock = ctByteArray[len(ctByteArray) -
(i + 1) * 16:len(ctByteArray) - i * 16]
temp = AES_ECB.AESdecrypt(ctInputBlock, key)
newPtBlock = 0
if i == (len(ctByteArray) // 16 - 1):
newPtBlock = xorEnc.fixedXor(temp, IV)
else:
prevCtBlock = ctByteArray[len(ctByteArray) -
(i + 2) * 16:len(ctByteArray) -
(i + 1) * 16]
newPtBlock = xorEnc.fixedXor(temp, prevCtBlock)
for j in range(len(newPtBlock)):
pt.append(newPtBlock[len(newPtBlock) - j - 1])
pt = pt[::-1]
pt = bytes(pt)
return pt
def recoverKey():
payload = 'a' * 64
payload = bytes(payload.encode('latin1'))
ct = encrypt(payload)
modifiedCt = ct[:16]
modifiedCt += bytes(('\x00' * 16).encode('latin1'))
modifiedCt += ct[:16]
modifiedCt += ct[48:]
modifiedPt = decrypt(modifiedCt)
if modifiedPt != None:
key = ENC.fixedXor(modifiedPt[:16], modifiedPt[32:48])
return key
else:
print('Something went wrong :/')
return None