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pyln-proto: Added a couple of utilities to manage onions and zbase32

travis-debug
Christian Decker 5 years ago
committed by Rusty Russell
parent
commit
d3f6ebf911
  1. 236
      contrib/pyln-proto/pyln/proto/onion.py
  2. 70
      contrib/pyln-proto/pyln/proto/primitives.py
  3. 56
      contrib/pyln-proto/pyln/proto/zbase32.py
  4. 1
      contrib/pyln-proto/requirements.txt
  5. 32
      contrib/pyln-proto/tests/test_onion.py
  6. 30
      contrib/pyln-proto/tests/test_primitives.py

236
contrib/pyln-proto/pyln/proto/onion.py

@ -0,0 +1,236 @@
from .primitives import varint_decode, varint_encode
from io import BytesIO, SEEK_CUR
from binascii import hexlify, unhexlify
import struct
class OnionPayload(object):
@classmethod
def from_bytes(cls, b):
if isinstance(b, bytes):
b = BytesIO(b)
realm = b.read(1)
b.seek(-1, SEEK_CUR)
if realm == b'\x00':
return LegacyOnionPayload.from_bytes(b)
elif realm != b'\x01':
return TlvPayload.from_bytes(b, skip_length=False)
else:
raise ValueError("Onion payloads with realm 0x01 are unsupported")
@classmethod
def from_hex(cls, s):
if isinstance(s, str):
s = s.encode('ASCII')
return cls.from_bytes(bytes(unhexlify(s)))
def to_bytes(self):
raise ValueError("OnionPayload is an abstract class, use "
"LegacyOnionPayload or TlvPayload instead")
def to_hex(self):
return hexlify(self.to_bytes()).decode('ASCII')
class LegacyOnionPayload(OnionPayload):
def __init__(self, amt_to_forward, outgoing_cltv_value,
short_channel_id=None, padding=None):
assert(padding is None or len(padding) == 12)
self.padding = b'\x00' * 12 if padding is None else padding
if isinstance(amt_to_forward, str):
self.amt_to_forward = int(amt_to_forward)
else:
self.amt_to_forward = amt_to_forward
self.outgoing_cltv_value = outgoing_cltv_value
if isinstance(short_channel_id, str) and 'x' in short_channel_id:
# Convert the short_channel_id from its string representation to its numeric representation
block, tx, out = short_channel_id.split('x')
num_scid = int(block) << 40 | int(tx) << 16 | int(out)
self.short_channel_id = num_scid
elif isinstance(short_channel_id, int):
self.short_channel_id = short_channel_id
else:
raise ValueError("short_channel_id format cannot be recognized: {}".format(short_channel_id))
@classmethod
def from_bytes(cls, b):
if isinstance(b, bytes):
b = BytesIO(b)
assert(b.read(1) == b'\x00')
s, a, o = struct.unpack("!QQL", b.read(20))
padding = b.read(12)
return LegacyOnionPayload(a, o, s, padding)
def to_bytes(self, include_realm=True):
b = b''
if include_realm:
b += b'\x00'
b += struct.pack("!Q", self.short_channel_id)
b += struct.pack("!Q", self.amt_to_forward)
b += struct.pack("!L", self.outgoing_cltv_value)
b += self.padding
assert(len(b) == 32 + include_realm)
return b
def to_hex(self, include_realm=True):
return hexlify(self.to_bytes(include_realm)).decode('ASCII')
def __str__(self):
return ("LegacyOnionPayload[scid={self.short_channel_id}, "
"amt_to_forward={self.amt_to_forward}, "
"outgoing_cltv={self.outgoing_cltv_value}]").format(self=self)
class TlvPayload(OnionPayload):
def __init__(self, fields=None):
self.fields = [] if fields is None else fields
@classmethod
def from_bytes(cls, b, skip_length=False):
if isinstance(b, str):
b = b.encode('ASCII')
if isinstance(b, bytes):
b = BytesIO(b)
if skip_length:
# Consume the entire remainder of the buffer.
payload_length = len(b.getvalue()) - b.tell()
else:
payload_length = varint_decode(b)
instance = TlvPayload()
start = b.tell()
while b.tell() < start + payload_length:
typenum = varint_decode(b)
if typenum is None:
break
length = varint_decode(b)
if length is None:
raise ValueError(
"Unable to read length at position {}".format(b.tell())
)
val = b.read(length)
# Get the subclass that is the correct interpretation of this
# field. Default to the binary field type.
c = tlv_types.get(typenum, (TlvField, "unknown"))
cls = c[0]
field = cls.from_bytes(typenum=typenum, b=val, description=c[1])
instance.fields.append(field)
return instance
@classmethod
def from_hex(cls, h):
return cls.from_bytes(unhexlify(h))
def add_field(self, typenum, value):
self.fields.append(TlvField(typenum=typenum, value=value))
def get(self, key, default=None):
for f in self.fields:
if f.typenum == key:
return f
return default
def to_bytes(self):
ser = [f.to_bytes() for f in self.fields]
b = BytesIO()
varint_encode(sum([len(b) for b in ser]), b)
for f in ser:
b.write(f)
return b.getvalue()
def __str__(self):
return "TlvPayload[" + ', '.join([str(f) for f in self.fields]) + "]"
class TlvField(object):
def __init__(self, typenum, value=None, description=None):
self.typenum = typenum
self.value = value
self.description = description
@classmethod
def from_bytes(cls, typenum, b, description=None):
return TlvField(typenum=typenum, value=b, description=description)
def __str__(self):
return "TlvField[{description},{num}={hex}]".format(
description=self.description,
num=self.typenum,
hex=hexlify(self.value).decode('ASCII')
)
def to_bytes(self):
b = BytesIO()
varint_encode(self.typenum, b)
varint_encode(len(self.value), b)
b.write(self.value)
return b.getvalue()
class Tu32Field(TlvField):
pass
class Tu64Field(TlvField):
pass
class ShortChannelIdField(TlvField):
pass
class TextField(TlvField):
@classmethod
def from_bytes(cls, typenum, b, description=None):
val = b.decode('UTF-8')
return TextField(typenum, value=val, description=description)
def to_bytes(self):
b = BytesIO()
val = self.value.encode('UTF-8')
varint_encode(self.typenum, b)
varint_encode(len(val), b)
b.write(val)
return b.getvalue()
def __str__(self):
return "TextField[{description},{num}=\"{val}\"]".format(
description=self.description,
num=self.typenum,
val=self.value,
)
class HashField(TlvField):
pass
class SignatureField(TlvField):
pass
# A mapping of known TLV types
tlv_types = {
2: (Tu64Field, 'amt_to_forward'),
4: (Tu32Field, 'outgoing_cltv_value'),
6: (ShortChannelIdField, 'short_channel_id'),
34349334: (TextField, 'noise_message_body'),
34349336: (SignatureField, 'noise_message_signature'),
}

70
contrib/pyln-proto/pyln/proto/primitives.py

@ -0,0 +1,70 @@
import struct
def varint_encode(i, w):
"""Encode an integer `i` into the writer `w`
"""
if i < 0xFD:
w.write(struct.pack("!B", i))
elif i <= 0xFFFF:
w.write(struct.pack("!BH", 0xFD, i))
elif i <= 0xFFFFFFFF:
w.write(struct.pack("!BL", 0xFE, i))
else:
w.write(struct.pack("!BQ", 0xFF, i))
def varint_decode(r):
"""Decode an integer from reader `r`
"""
raw = r.read(1)
if len(raw) != 1:
return None
i, = struct.unpack("!B", raw)
if i < 0xFD:
return i
elif i == 0xFD:
return struct.unpack("!H", r.read(2))[0]
elif i == 0xFE:
return struct.unpack("!L", r.read(4))[0]
else:
return struct.unpack("!Q", r.read(8))[0]
class ShortChannelId(object):
def __init__(self, block, txnum, outnum):
self.block = block
self.txnum = txnum
self.outnum = outnum
@classmethod
def from_bytes(cls, b):
assert(len(b) == 8)
i, = struct.unpack("!Q", b)
return cls.from_int(i)
@classmethod
def from_int(cls, i):
block = (i >> 40) & 0xFFFFFF
txnum = (i >> 16) & 0xFFFFFF
outnum = (i >> 0) & 0xFFFF
return cls(block=block, txnum=txnum, outnum=outnum)
@classmethod
def from_str(self, s):
block, txnum, outnum = s.split('x')
return ShortChannelId(block=int(block), txnum=int(txnum),
outnum=int(outnum))
def to_int(self):
return self.block << 40 | self.txnum << 16 | self.outnum
def to_bytes(self):
return struct.pack("!Q", self.to_int())
def __str__(self):
return "{self.block}x{self.txnum}x{self.outnum}".format(self=self)
def __eq__(self, other):
return self.block == other.block and self.txnum == other.txnum and self.outnum == other.outnum

56
contrib/pyln-proto/pyln/proto/zbase32.py

@ -0,0 +1,56 @@
import bitstring
zbase32_chars = b'ybndrfg8ejkmcpqxot1uwisza345h769'
zbase32_revchars = [
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 18, 255, 25, 26, 27, 30, 29, 7, 31, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 24, 1, 12, 3, 8, 5, 6, 28, 21, 9, 10, 255, 11, 2,
16, 13, 14, 4, 22, 17, 19, 255, 20, 15, 0, 23, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255
]
def bitarray_to_u5(barr):
assert len(barr) % 5 == 0
ret = []
s = bitstring.ConstBitStream(barr)
while s.pos != s.len:
ret.append(s.read(5).uint)
return ret
def u5_to_bitarray(arr):
ret = bitstring.BitArray()
for a in arr:
ret += bitstring.pack("uint:5", a)
return ret
def encode(b):
uint5s = bitarray_to_u5(b)
res = [zbase32_chars[c] for c in uint5s]
return bytes(res)
def decode(b):
if isinstance(b, str):
b = b.encode('ASCII')
uint5s = []
for c in b:
uint5s.append(zbase32_revchars[c])
dec = u5_to_bitarray(uint5s)
return dec.bytes

1
contrib/pyln-proto/requirements.txt

@ -1,2 +1,3 @@
bitstring==3.1.6
cryptography==2.7
coincurve==12.0.0

32
contrib/pyln-proto/tests/test_onion.py

@ -0,0 +1,32 @@
from binascii import unhexlify
from pyln.proto import onion
def test_legacy_payload():
legacy = unhexlify(
b'00000067000001000100000000000003e800000075000000000000000000000000'
)
payload = onion.OnionPayload.from_bytes(legacy)
assert(payload.to_bytes(include_realm=True) == legacy)
def test_tlv_payload():
tlv = unhexlify(
b'58fe020c21160c48656c6c6f20776f726c6421fe020c21184076e8acd54afbf2361'
b'0b7166ba689afcc9e8ec3c44e442e765012dfc1d299958827d0205f7e4e1a12620e'
b'7fc8ce1c7d3651acefde899c33f12b6958d3304106a0'
)
payload = onion.OnionPayload.from_bytes(tlv)
assert(payload.to_bytes() == tlv)
fields = payload.fields
assert(len(fields) == 2)
assert(isinstance(fields[0], onion.TextField))
assert(fields[0].typenum == 34349334 and fields[0].value == "Hello world!")
assert(fields[1].typenum == 34349336 and fields[1].value == unhexlify(
b'76e8acd54afbf23610b7166ba689afcc9e8ec3c44e442e765012dfc1d299958827d'
b'0205f7e4e1a12620e7fc8ce1c7d3651acefde899c33f12b6958d3304106a0'
))
assert(payload.to_bytes() == tlv)

30
contrib/pyln-proto/tests/test_primitives.py

@ -0,0 +1,30 @@
from binascii import hexlify, unhexlify
from pyln.proto import zbase32
from pyln.proto.primitives import ShortChannelId
def test_short_channel_id():
num = 618150934845652992
b = unhexlify(b'08941d00090d0000')
s = '562205x2317x0'
s1 = ShortChannelId.from_int(num)
s2 = ShortChannelId.from_str(s)
s3 = ShortChannelId.from_bytes(b)
expected = ShortChannelId(block=562205, txnum=2317, outnum=0)
assert(s1 == expected)
assert(s2 == expected)
assert(s3 == expected)
assert(expected.to_bytes() == b)
assert(str(expected) == s)
assert(expected.to_int() == num)
def test_zbase32():
zb32 = b'd75qtmgijm79rpooshmgzjwji9gj7dsdat8remuskyjp9oq1ugkaoj6orbxzhuo4njtyh96e3aq84p1tiuz77nchgxa1s4ka4carnbiy'
b = zbase32.decode(zb32)
assert(hexlify(b) == b'1f76e8acd54afbf23610b7166ba689afcc9e8ec3c44e442e765012dfc1d299958827d0205f7e4e1a12620e7fc8ce1c7d3651acefde899c33f12b6958d3304106a0')
enc = zbase32.encode(b)
assert(enc == zb32)
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