1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
# -*- coding: utf-8 -*-
from ..ecc.curve import Curve
from ..kdf.derivedrootsecrets import DerivedRootSecrets
from .chainkey import ChainKey
class RootKey:
def __init__(self, kdf, key):
self.kdf = kdf
self.key = key
def getKeyBytes(self):
return self.key
def createChain(self, ECPublicKey_theirRatchetKey, ECKeyPair_ourRatchetKey):
sharedSecret = Curve.calculateAgreement(ECPublicKey_theirRatchetKey, ECKeyPair_ourRatchetKey.getPrivateKey())
derivedSecretBytes = self.kdf.deriveSecrets(sharedSecret,
"WhisperRatchet".encode(),
DerivedRootSecrets.SIZE,
salt=self.key)
derivedSecrets = DerivedRootSecrets(derivedSecretBytes)
newRootKey = RootKey(self.kdf, derivedSecrets.getRootKey())
newChainKey = ChainKey(self.kdf, derivedSecrets.getChainKey(), 0)
return (newRootKey, newChainKey)
|
