Files
py-libp2p/libp2p/security/noise/io.py
2025-08-08 02:01:36 +00:00

93 lines
3.0 KiB
Python

from typing import (
cast,
)
from noise.connection import NoiseConnection as NoiseState
from libp2p.abc import (
IRawConnection,
)
from libp2p.io.abc import (
EncryptedMsgReadWriter,
ReadWriteCloser,
)
from libp2p.io.msgio import (
FixedSizeLenMsgReadWriter,
)
SIZE_NOISE_MESSAGE_LEN = 2
MAX_NOISE_MESSAGE_LEN = 2 ** (8 * SIZE_NOISE_MESSAGE_LEN) - 1
SIZE_NOISE_MESSAGE_BODY_LEN = 2
MAX_NOISE_MESSAGE_BODY_LEN = MAX_NOISE_MESSAGE_LEN - SIZE_NOISE_MESSAGE_BODY_LEN
BYTE_ORDER = "big"
# | Noise packet |
# < 2 bytes -><- 65535 ->
# | noise msg len | noise msg |
class NoisePacketReadWriter(FixedSizeLenMsgReadWriter):
size_len_bytes = SIZE_NOISE_MESSAGE_LEN
class BaseNoiseMsgReadWriter(EncryptedMsgReadWriter):
"""
The base implementation of noise message reader/writer.
`encrypt` and `decrypt` are not implemented here, which should be
implemented by the subclasses.
"""
read_writer: NoisePacketReadWriter
noise_state: NoiseState
# NOTE: This prefix is added in msg#3 in Go.
# Support in py-libp2p is available but not used
prefix: bytes = b"\x00" * 32
def __init__(self, conn: IRawConnection, noise_state: NoiseState) -> None:
self.read_writer = NoisePacketReadWriter(cast(ReadWriteCloser, conn))
self.noise_state = noise_state
async def write_msg(self, msg: bytes, prefix_encoded: bool = False) -> None:
data_encrypted = self.encrypt(msg)
if prefix_encoded:
# Manually add the prefix if needed
data_encrypted = self.prefix + data_encrypted
await self.read_writer.write_msg(data_encrypted)
async def read_msg(self, prefix_encoded: bool = False) -> bytes:
noise_msg_encrypted = await self.read_writer.read_msg()
if prefix_encoded:
return self.decrypt(noise_msg_encrypted[len(self.prefix) :])
else:
return self.decrypt(noise_msg_encrypted)
async def close(self) -> None:
await self.read_writer.close()
def get_remote_address(self) -> tuple[str, int] | None:
# Delegate to the underlying connection if possible
if hasattr(self.read_writer, "read_write_closer") and hasattr(
self.read_writer.read_write_closer,
"get_remote_address",
):
return self.read_writer.read_write_closer.get_remote_address()
return None
class NoiseHandshakeReadWriter(BaseNoiseMsgReadWriter):
def encrypt(self, data: bytes) -> bytes:
return bytes(self.noise_state.write_message(data))
def decrypt(self, data: bytes) -> bytes:
return bytes(self.noise_state.read_message(data))
class NoiseTransportReadWriter(BaseNoiseMsgReadWriter):
def encrypt(self, data: bytes) -> bytes:
return self.noise_state.encrypt(data)
def decrypt(self, data: bytes) -> bytes:
return self.noise_state.decrypt(data)