avoid duplicating bech32 module

electrum/segwit_addr.py

@@ -59,14 +59,14 @@ def bech32_encode(hrp, data):
     return hrp + '1' + ''.join([CHARSET[d] for d in combined])
 
 
-def bech32_decode(bech):
+def bech32_decode(bech, ignore_long_length=False):
     """Validate a Bech32 string, and determine HRP and data."""
     if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
             (bech.lower() != bech and bech.upper() != bech)):
         return (None, None)
     bech = bech.lower()
     pos = bech.rfind('1')
-    if pos < 1 or pos + 7 > len(bech) or len(bech) > 90:
+    if pos < 1 or pos + 7 > len(bech) or (not ignore_long_length and len(bech) > 90):
         return (None, None)
     if not all(x in CHARSET for x in bech[pos+1:]):
         return (None, None)

lib/lightning_payencode/bech32.py

@@ -1,123 +0,0 @@
-# Copyright (c) 2017 Pieter Wuille
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-# THE SOFTWARE.
-
-"""Reference implementation for Bech32 and segwit addresses."""
-
-
-CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
-
-
-def bech32_polymod(values):
-    """Internal function that computes the Bech32 checksum."""
-    generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
-    chk = 1
-    for value in values:
-        top = chk >> 25
-        chk = (chk & 0x1ffffff) << 5 ^ value
-        for i in range(5):
-            chk ^= generator[i] if ((top >> i) & 1) else 0
-    return chk
-
-
-def bech32_hrp_expand(hrp):
-    """Expand the HRP into values for checksum computation."""
-    return [ord(x) >> 5 for x in hrp] + [0] + [ord(x) & 31 for x in hrp]
-
-
-def bech32_verify_checksum(hrp, data):
-    """Verify a checksum given HRP and converted data characters."""
-    return bech32_polymod(bech32_hrp_expand(hrp) + data) == 1
-
-
-def bech32_create_checksum(hrp, data):
-    """Compute the checksum values given HRP and data."""
-    values = bech32_hrp_expand(hrp) + data
-    polymod = bech32_polymod(values + [0, 0, 0, 0, 0, 0]) ^ 1
-    return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)]
-
-
-def bech32_encode(hrp, data):
-    """Compute a Bech32 string given HRP and data values."""
-    combined = data + bech32_create_checksum(hrp, data)
-    return hrp + '1' + ''.join([CHARSET[d] for d in combined])
-
-
-def bech32_decode(bech):
-    """Validate a Bech32 string, and determine HRP and data."""
-    if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
-            (bech.lower() != bech and bech.upper() != bech)):
-        return (None, None)
-    bech = bech.lower()
-    pos = bech.rfind('1')
-    if pos < 1 or pos + 7 > len(bech): #or len(bech) > 90:
-        return (None, None)
-    if not all(x in CHARSET for x in bech[pos+1:]):
-        return (None, None)
-    hrp = bech[:pos]
-    data = [CHARSET.find(x) for x in bech[pos+1:]]
-    if not bech32_verify_checksum(hrp, data):
-        return (None, None)
-    return (hrp, data[:-6])
-
-
-def convertbits(data, frombits, tobits, pad=True):
-    """General power-of-2 base conversion."""
-    acc = 0
-    bits = 0
-    ret = []
-    maxv = (1 << tobits) - 1
-    max_acc = (1 << (frombits + tobits - 1)) - 1
-    for value in data:
-        if value < 0 or (value >> frombits):
-            return None
-        acc = ((acc << frombits) | value) & max_acc
-        bits += frombits
-        while bits >= tobits:
-            bits -= tobits
-            ret.append((acc >> bits) & maxv)
-    if pad:
-        if bits:
-            ret.append((acc << (tobits - bits)) & maxv)
-    elif bits >= frombits or ((acc << (tobits - bits)) & maxv):
-        return None
-    return ret
-
-
-def decode(hrp, addr):
-    """Decode a segwit address."""
-    hrpgot, data = bech32_decode(addr)
-    if hrpgot != hrp:
-        return (None, None)
-    decoded = convertbits(data[1:], 5, 8, False)
-    if decoded is None or len(decoded) < 2 or len(decoded) > 40:
-        return (None, None)
-    if data[0] > 16:
-        return (None, None)
-    if data[0] == 0 and len(decoded) != 20 and len(decoded) != 32:
-        return (None, None)
-    return (data[0], decoded)
-
-
-def encode(hrp, witver, witprog):
-    """Encode a segwit address."""
-    ret = bech32_encode(hrp, [witver] + convertbits(witprog, 8, 5))
-    assert decode(hrp, ret) is not (None, None)
-    return ret
-

lib/lightning_payencode/lnaddr.py

@@ -2,7 +2,7 @@
 import traceback
 import ecdsa.curves
 from ..bitcoin import MyVerifyingKey, GetPubKey
-from .bech32 import bech32_encode, bech32_decode, CHARSET
+from ..segwit_addr import bech32_encode, bech32_decode, CHARSET
 from binascii import hexlify, unhexlify
 from bitstring import BitArray
 from decimal import Decimal
@@ -79,7 +79,7 @@ def encode_fallback(fallback, currency):
     """ Encode all supported fallback addresses.
     """
     if currency == 'bc' or currency == 'tb':
-        fbhrp, witness = bech32_decode(fallback)
+        fbhrp, witness = bech32_decode(fallback, ignore_long_length=True)
         if fbhrp:
             if fbhrp != currency:
                 raise ValueError("Not a bech32 address for this currency")
@@ -251,7 +251,7 @@ class LnAddr(object):
         )
 
 def lndecode(a, verbose=False):
-    hrp, data = bech32_decode(a)
+    hrp, data = bech32_decode(a, ignore_long_length=True)
     if not hrp:
         raise ValueError("Bad bech32 checksum")