AaronFiore/electrum
1
0
Fork 0
Code Activity

lnaddr: add feature bit support to invoices

Browse Source 
see https://github.com/lightningnetwork/lightning-rfc/pull/656
This commit is contained in:
SomberNight
2020-03-24 15:31:19 +01:00
parent a66437f399
commit 4b78bf94d4
5 changed files with 64 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
electrum/lnaddr.py
View File

@@ -141,6 +141,14 @@ def tagged(char, l):
def tagged_bytes(char, l):
return tagged(char, bitstring.BitArray(l))
def trim_to_min_length(bits):
# Get minimal length by trimming leading 5 bits at a time.
while bits.startswith('0b00000'):
if len(bits) == 5:
break # v == 0
bits = bits[5:]
return bits
# Discard trailing bits, convert to bytes.
def trim_to_bytes(barr):
# Adds a byte if necessary.
@@ -155,7 +163,7 @@ def pull_tagged(stream):
length = stream.read(5).uint * 32 + stream.read(5).uint
return (CHARSET[tag], stream.read(length * 5), stream)
def lnencode(addr, privkey):
def lnencode(addr: 'LnAddr', privkey):
if addr.amount:
amount = Decimal(str(addr.amount))
# We can only send down to millisatoshi.
@@ -196,23 +204,24 @@ def lnencode(addr, privkey):
elif k == 'd':
data += tagged_bytes('d', v.encode())
elif k == 'x':
# Get minimal length by trimming leading 5 bits at a time.
expirybits = bitstring.pack('intbe:64', v)[4:64]
while expirybits.startswith('0b00000'):
if len(expirybits) == 5:
break # v == 0
expirybits = expirybits[5:]
expirybits = trim_to_min_length(expirybits)
data += tagged('x', expirybits)
elif k == 'h':
data += tagged_bytes('h', sha256(v.encode('utf-8')).digest())
elif k == 'n':
data += tagged_bytes('n', v)
elif k == 'c':
# Get minimal length by trimming leading 5 bits at a time.
finalcltvbits = bitstring.pack('intbe:64', v)[4:64]
while finalcltvbits.startswith('0b00000'):
finalcltvbits = finalcltvbits[5:]
finalcltvbits = trim_to_min_length(finalcltvbits)
data += tagged('c', finalcltvbits)
elif k == '9':
if v == 0:
continue
feature_bits = bitstring.BitArray(uint=v, length=v.bit_length())
while feature_bits.len % 5 != 0:
feature_bits.prepend('0b0')
data += tagged('9', feature_bits)
else:
# FIXME: Support unknown tags?
raise ValueError("Unknown tag {}".format(k))
@@ -247,7 +256,7 @@ class LnAddr(object):
self.signature = None
self.pubkey = None
self.currency = constants.net.SEGWIT_HRP if currency is None else currency
self.amount = amount
self.amount = amount # in bitcoins
self._min_final_cltv_expiry = 9
def __str__(self):
@@ -389,8 +398,16 @@ def lndecode(invoice: str, *, verbose=False, expected_hrp=None) -> LnAddr:
continue
pubkeybytes = trim_to_bytes(tagdata)
addr.pubkey = pubkeybytes
elif tag == 'c':
addr._min_final_cltv_expiry = tagdata.int
elif tag == '9':
features = tagdata.uint
addr.tags.append(('9', features))
from .lnutil import validate_features
validate_features(features)
else:
addr.unknown_tags.append((tag, tagdata))