mirror of
https://github.com/trezor/trezor-firmware.git
synced 2025-07-02 21:02:34 +00:00
72 lines
2.3 KiB
Python
72 lines
2.3 KiB
Python
from ustruct import pack, unpack
|
|
|
|
from trezor import wire
|
|
from trezor.crypto.hashlib import sha256
|
|
from trezor.messages.ECDHSessionKey import ECDHSessionKey
|
|
from trezor.ui.text import Text
|
|
from trezor.utils import chunks
|
|
|
|
from apps.common import HARDENED
|
|
from apps.common.confirm import require_confirm
|
|
from apps.common.keychain import get_keychain
|
|
|
|
from .sign_identity import serialize_identity, serialize_identity_without_proto
|
|
|
|
|
|
async def get_ecdh_session_key(ctx, msg):
|
|
if msg.ecdsa_curve_name is None:
|
|
msg.ecdsa_curve_name = "secp256k1"
|
|
|
|
keychain = await get_keychain(ctx, msg.ecdsa_curve_name, [[]])
|
|
identity = serialize_identity(msg.identity)
|
|
|
|
await require_confirm_ecdh_session_key(ctx, msg.identity)
|
|
|
|
address_n = get_ecdh_path(identity, msg.identity.index or 0)
|
|
node = keychain.derive(address_n)
|
|
|
|
session_key = ecdh(
|
|
seckey=node.private_key(),
|
|
peer_public_key=msg.peer_public_key,
|
|
curve=msg.ecdsa_curve_name,
|
|
)
|
|
return ECDHSessionKey(session_key=session_key)
|
|
|
|
|
|
async def require_confirm_ecdh_session_key(ctx, identity):
|
|
lines = chunks(serialize_identity_without_proto(identity), 18)
|
|
proto = identity.proto.upper() if identity.proto else "identity"
|
|
text = Text("Decrypt %s" % proto)
|
|
text.mono(*lines)
|
|
await require_confirm(ctx, text)
|
|
|
|
|
|
def get_ecdh_path(identity: str, index: int):
|
|
identity_hash = sha256(pack("<I", index) + identity).digest()
|
|
|
|
address_n = (17,) + unpack("<IIII", identity_hash[:16])
|
|
address_n = [HARDENED | x for x in address_n]
|
|
|
|
return address_n
|
|
|
|
|
|
def ecdh(seckey: bytes, peer_public_key: bytes, curve: str) -> bytes:
|
|
if curve == "secp256k1":
|
|
from trezor.crypto.curve import secp256k1
|
|
|
|
session_key = secp256k1.multiply(seckey, peer_public_key)
|
|
elif curve == "nist256p1":
|
|
from trezor.crypto.curve import nist256p1
|
|
|
|
session_key = nist256p1.multiply(seckey, peer_public_key)
|
|
elif curve == "curve25519":
|
|
from trezor.crypto.curve import curve25519
|
|
|
|
if peer_public_key[0] != 0x40:
|
|
raise wire.DataError("Curve25519 public key should start with 0x40")
|
|
session_key = b"\x04" + curve25519.multiply(seckey, peer_public_key[1:])
|
|
else:
|
|
raise wire.DataError("Unsupported curve for ECDH: " + curve)
|
|
|
|
return session_key
|