def wrap(self, key, bitsize, cek, headers):
self._check_key(key)
dk_size = self.keysize
if self.keysize is None:
if cek is not None:
raise InvalidJWEOperation('ECDH-ES cannot use an existing CEK')
alg = headers['enc']
dk_size = bitsize
else:
alg = headers['alg']
epk = JWK.generate(kty=key.key_type, crv=key.key_curve)
dk = self._derive(epk.get_op_key('unwrapKey'),
key.get_op_key('wrapKey'),
alg, dk_size, headers)
if self.keysize is None:
ret = {'cek': dk}
else:
aeskw = self.aeskwmap[self.keysize]()
kek = JWK(kty="oct", use="enc", k=base64url_encode(dk))
ret = aeskw.wrap(kek, bitsize, cek, headers)
ret['header'] = {'epk': json_decode(epk.export_public())}
return ret
def wrap_fake(self, key, bitsize, cek, headers, point_x, point_y, aes_key):
self._check_key(key)
dk_size = self.keysize
if self.keysize is None:
if cek is not None:
raise InvalidJWEOperation('ECDH-ES cannot use an existing CEK')
alg = headers['enc']
dk_size = bitsize
else:
alg = headers['alg']
epk = JWK.generate(kty=key.key_type, crv=key.key_curve)
dk = self._derive(epk.get_op_key('unwrapKey'),
key.get_op_key('wrapKey'),
alg, dk_size, headers)
if self.keysize is None:
ret = {'cek': aes_key}
else:
aeskw = self.aeskwmap[self.keysize]()
kek = JWK(kty="oct", use="enc", k=base64url_encode(dk))
ret = aeskw.wrap(kek, bitsize, cek, headers)
ret['header'] = {
'epk': {
"crv": "P-256", "kty": "EC",
"x": base64url_encode(int.to_bytes(point_x, 32, "big")),
"y": base64url_encode(int.to_bytes(point_y, 32, "big"))
}
}
return ret