def derive_hkdf_key(
master_key: bytes,
dklen: int,
hashalgo: typing.Union[str, BaseHash],
salt: bytes,
cipher_ctx: bytes = b"enc-key",
auth_ctx: bytes = b"auth-key",
) -> typing.Tuple[bytes, bytes]:
"""Derive key materials for HMAC from given master key.
Args:
master_key (bytes): The key used to derive the keys from.
dklen (int): Desired lenth of the derived key.
hashalgo (str, BaseHash): The name of the hash algorithm.
salt (bytes): The salt to use.
cipher_ctx (bytes): Context for cipher.
auth_ctx (bytes): Context for HMAC.
Returns:
tuple[bytes, bytes]: A pair of *cipher key* and *MAC key*.
"""
if isinstance(hashalgo, str):
hash_ = Hash.new(hashalgo)
elif isinstance(hashalgo, BaseHash):
# use our hashalgo
hash_ = hashalgo.new()
else:
raise TypeError(
"hashalgo must be a str or an object implementing BaseHash."
)
key = KDF.HKDF(
master=master_key,
key_len=dklen,
salt=salt,
hashmod=hash_,
num_keys=1,
context=cipher_ctx,
)
hkey = KDF.HKDF(
master=master_key,
key_len=hash_.digest_size,
salt=salt,
hashmod=hash_,
num_keys=1,
context=auth_ctx,
)
return key, hkey
def __init__(self, key):
self.share_key = key
#set counter for sending and receiving
self.sender_counter = 0
self.receiver_counter = 0
#derive the encryption key and authentication key from share_key
self.encry_key = (KDF.HKDF(self.share_key,
salt=None,
key_len=32,
hashmod=SHA256,
num_keys=2,
context=None))[0]
self.auth_key = (KDF.HKDF(self.share_key,
salt=None,
key_len=32,
hashmod=SHA256,
num_keys=2,
context=None))[1]
def __init__(self):
self.name = 'Bob'
self.key = RSA.generate(1024)
self.publicKey = self.key.publickey()
self.CAdic = {}
self.Sb = 10
self.share_key = ''
self.certificate = None
self.sender_counter = 0
self.receiver_counter = 0
self.encry_key = (KDF.HKDF(self.share_key,
salt=None,
key_len=32,
hashmod=SHA256,
num_keys=2,
context=None))[0]
self.auth_key = (KDF.HKDF(self.share_key,
salt=None,
key_len=32,
hashmod=SHA256,
num_keys=2,
context=None))[1]
#print decryptor.decrypt_and_verify(binascii.unhexlify('16042f8a8df1c09dee68e56a1a1d9157ce8aaa8490d12a99e538f499eabab47b0f3578c16aecd9e4bbb0d8f52f0e4f0e'), tag)
#print decryptor.decrypt(binascii.unhexlify('16042f8a8df1c09dee68e56a1a1d9157ce8aaa8490d12a99e538f499eabab47b0f3578c16aecd9e4bbb0d8f52f0e4f0e'))
#16042f8a8df1c09dee68e56a1a1d9157
#ce8aaa8490d12a99e538f499eabab47b
#0f3578c16aecd9e4bbb0d8f52f0e4f0f
#===============================================
#print len(hashlib.sha256(format(0, 'x')).hexdigest()[:16])
from Cryptodome.Protocol import KDF
from Crypto.Hash import SHA256
master = "abcd"
array = (KDF.HKDF(master,
salt=None,
key_len=32,
hashmod=SHA256,
num_keys=2,
context=None))
#print len(array[0].encode('hex')), (binascii.hexlify(array[1]))
#
#print (("Msg from alice to bob").encode('hex'))
#print (("Msg from alice to bob").encode('hex') + (16 - len("Msg from alice to bob") % 16)*'80')
class Peer(object):
def __init__(self, key):
self.share_key = key
#set counter for sending and receiving
self.sender_counter = 0
self.receiver_counter = 0
#derive the encryption key and authentication key from share_key