def checkTemplate(rpc: RPC, mnemonic: str, req: Dict[str, Any],
inputs: List[Dict[str, Any]],
outputs: List[Dict[str, Any]]) -> None:
template: Dict[str, Any] = rpc.call("personal", "getTransactionTemplate",
req)
if template["type"] != "Send":
raise TestError("Template isn't of type Send.")
if sortUTXOs(template["inputs"]) != sortUTXOs(inputs):
raise TestError("Template inputs aren't as expected.")
if template["outputs"] != outputs:
raise TestError("Template outputs are incorrect.")
keys: List[bytes] = []
for inputJSON in template["inputs"]:
key: bytes
if inputJSON["change"]:
key = getChangePublicKey(mnemonic, "", inputJSON["index"])
else:
key = getPublicKey(mnemonic, "", inputJSON["index"])
if key not in keys:
keys.append(key)
if template["publicKey"] != Ristretto.aggregate(
[Ristretto.RistrettoPoint(key)
for key in keys]).serialize().hex().upper():
if len(keys) == 1:
raise TestError(
"Template public key isn't correct when only a single key is present."
)
raise TestError("Public key aggregation isn't correct.")
def deriveKeyAndChainCode(
secret: bytes,
path: List[int]
) -> Tuple[bytes, bytes]:
k: bytes = hashlib.sha512(secret).digest()
kL: bytes = Ristretto.RistrettoScalar(k[:32]).serialize()
kR: bytes = k[32:]
k = kL + kR
#Parent public key/chain code.
A: bytes = Ristretto.RistrettoScalar(kL).toPoint().serialize()
c: bytes = hashlib.sha256(bytes([1]) + secret).digest()
#Derive each child.
for i in path:
iBytes: bytes = i.to_bytes(4, "little")
Z: bytes
if i < HARDENED_THRESHOLD:
Z = hmac512(c, bytes([2]) + A + iBytes)
c = hmac512(c, bytes([3]) + A + iBytes)[32:]
else:
Z = hmac512(c, bytes([0]) + k + iBytes)
c = hmac512(c, bytes([1]) + k + iBytes)[32:]
zR: bytes = Z[32:]
#This performs a mod l on kL which the BIP32-Ed25519 doesn't specify. That said, it's required to form a valid private key.
scalar: Ristretto.Scalar = (
Ristretto.RistrettoScalar(int.from_bytes(Z[:32], "little")) +
Ristretto.RistrettoScalar(int.from_bytes(kL, "little"))
)
if scalar.underlying == mpz(0):
raise Exception("Invalid child.")
kL = scalar.serialize()
kR = ((int.from_bytes(zR, "little") + int.from_bytes(kR, "little")) % (1 << 256)).to_bytes(32, "little")
k = kL + kR
A = Ristretto.RistrettoPoint(scalar.toPoint()).serialize()
return (k, c)
