lnaddr: clean-up SEGWIT_HRP vs BOLT11_HRP confusion

With signet, SEGWIT_HRP != BOLT11_HRP, so the previous "currency" string
became a flawed concept. Instead we pass around net objects now.

electrum/constants.py

@@ -26,7 +26,7 @@
 import os
 import json
 
-from .util import inv_dict
+from .util import inv_dict, all_subclasses
 from . import bitcoin
 
 
@@ -47,7 +47,17 @@ BIP39_WALLET_FORMATS = read_json('bip39_wallet_formats.json', [])
 
 class AbstractNet:
 
-    BLOCK_HEIGHT_FIRST_LIGHTNING_CHANNELS = 0
+    NET_NAME: str
+    TESTNET: bool
+    WIF_PREFIX: int
+    ADDRTYPE_P2PKH: int
+    ADDRTYPE_P2SH: int
+    SEGWIT_HRP: str
+    BOLT11_HRP: str
+    GENESIS: str
+    BLOCK_HEIGHT_FIRST_LIGHTNING_CHANNELS: int = 0
+    BIP44_COIN_TYPE: int
+    LN_REALM_BYTE: int
 
     @classmethod
     def max_checkpoint(cls) -> int:
@@ -171,6 +181,8 @@ class BitcoinSignet(BitcoinTestnet):
     LN_DNS_SEEDS = []
 
 
+NETS_LIST = tuple(all_subclasses(AbstractNet))
+
 # don't import net directly, import the module instead (so that net is singleton)
 net = BitcoinMainnet
 

electrum/gui/kivy/uix/screens.py

@@ -187,7 +187,7 @@ class SendScreen(CScreen, Logger):
     def set_ln_invoice(self, invoice: str):
         try:
             invoice = str(invoice).lower()
-            lnaddr = lndecode(invoice, expected_hrp=constants.net.SEGWIT_HRP)
+            lnaddr = lndecode(invoice)
         except Exception as e:
             self.app.show_info(invoice + _(" is not a valid Lightning invoice: ") + repr(e)) # repr because str(Exception()) == ''
             return

electrum/gui/qt/main_window.py

@@ -1969,7 +1969,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger):
     def parse_lightning_invoice(self, invoice):
         """Parse ln invoice, and prepare the send tab for it."""
         try:
-            lnaddr = lndecode(invoice, expected_hrp=constants.net.SEGWIT_HRP)
+            lnaddr = lndecode(invoice)
         except Exception as e:
             raise LnDecodeException(e) from e
         pubkey = bh2u(lnaddr.pubkey.serialize())
@@ -2180,7 +2180,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger):
         d.exec_()
 
     def show_lightning_invoice(self, invoice: LNInvoice):
-        lnaddr = lndecode(invoice.invoice, expected_hrp=constants.net.SEGWIT_HRP)
+        lnaddr = lndecode(invoice.invoice)
         d = WindowModalDialog(self, _("Lightning Invoice"))
         vbox = QVBoxLayout(d)
         grid = QGridLayout()

electrum/lnaddr.py

@@ -6,7 +6,7 @@ import time
 from hashlib import sha256
 from binascii import hexlify
 from decimal import Decimal
-from typing import Optional, TYPE_CHECKING
+from typing import Optional, TYPE_CHECKING, Type
 
 import random
 import bitstring
@@ -15,6 +15,7 @@ from .bitcoin import hash160_to_b58_address, b58_address_to_hash160, TOTAL_COIN_
 from .segwit_addr import bech32_encode, bech32_decode, CHARSET
 from . import segwit_addr
 from . import constants
+from .constants import AbstractNet
 from . import ecc
 from .bitcoin import COIN
 
@@ -83,57 +84,42 @@ def bitarray_to_u5(barr):
     return ret
 
 
-def encode_fallback(fallback: str, currency):
+def encode_fallback(fallback: str, net: Type[AbstractNet]):
     """ Encode all supported fallback addresses.
     """
-    if currency in [constants.BitcoinMainnet.SEGWIT_HRP, constants.BitcoinTestnet.SEGWIT_HRP]:
-        wver, wprog_ints = segwit_addr.decode_segwit_address(currency, fallback)
-        if wver is not None:
-            wprog = bytes(wprog_ints)
-        else:
-            addrtype, addr = b58_address_to_hash160(fallback)
-            if is_p2pkh(currency, addrtype):
-                wver = 17
-            elif is_p2sh(currency, addrtype):
-                wver = 18
-            else:
-                raise ValueError("Unknown address type for {}".format(currency))
-            wprog = addr
-        return tagged('f', bitstring.pack("uint:5", wver) + wprog)
+    wver, wprog_ints = segwit_addr.decode_segwit_address(net.SEGWIT_HRP, fallback)
+    if wver is not None:
+        wprog = bytes(wprog_ints)
     else:
-        raise NotImplementedError("Support for currency {} not implemented".format(currency))
-
-
-def parse_fallback(fallback, currency):
-    if currency in [constants.BitcoinMainnet.SEGWIT_HRP, constants.BitcoinTestnet.SEGWIT_HRP]:
-        wver = fallback[0:5].uint
-        if wver == 17:
-            addr=hash160_to_b58_address(fallback[5:].tobytes(), base58_prefix_map[currency][0])
-        elif wver == 18:
-            addr=hash160_to_b58_address(fallback[5:].tobytes(), base58_prefix_map[currency][1])
-        elif wver <= 16:
-            witprog = fallback[5:]  # cut witver
-            witprog = witprog[:len(witprog) // 8 * 8]  # can only be full bytes
-            witprog = witprog.tobytes()
-            addr = segwit_addr.encode_segwit_address(currency, wver, witprog)
+        addrtype, addr = b58_address_to_hash160(fallback)
+        if addrtype == net.ADDRTYPE_P2PKH:
+            wver = 17
+        elif addrtype == net.ADDRTYPE_P2SH:
+            wver = 18
         else:
-            return None
+            raise ValueError(f"Unknown address type {addrtype} for {net}")
+        wprog = addr
+    return tagged('f', bitstring.pack("uint:5", wver) + wprog)
+
+
+def parse_fallback(fallback, net: Type[AbstractNet]):
+    wver = fallback[0:5].uint
+    if wver == 17:
+        addr = hash160_to_b58_address(fallback[5:].tobytes(), net.ADDRTYPE_P2PKH)
+    elif wver == 18:
+        addr = hash160_to_b58_address(fallback[5:].tobytes(), net.ADDRTYPE_P2SH)
+    elif wver <= 16:
+        witprog = fallback[5:]  # cut witver
+        witprog = witprog[:len(witprog) // 8 * 8]  # can only be full bytes
+        witprog = witprog.tobytes()
+        addr = segwit_addr.encode_segwit_address(net.SEGWIT_HRP, wver, witprog)
     else:
-        addr=fallback.tobytes()
+        return None
     return addr
 
 
-# Map of classical and witness address prefixes
-base58_prefix_map = {
-    constants.BitcoinMainnet.SEGWIT_HRP : (constants.BitcoinMainnet.ADDRTYPE_P2PKH, constants.BitcoinMainnet.ADDRTYPE_P2SH),
-    constants.BitcoinTestnet.SEGWIT_HRP : (constants.BitcoinTestnet.ADDRTYPE_P2PKH, constants.BitcoinTestnet.ADDRTYPE_P2SH)
-}
-
-def is_p2pkh(currency, prefix):
-    return prefix == base58_prefix_map[currency][0]
+BOLT11_HRP_INV_DICT = {net.BOLT11_HRP: net for net in constants.NETS_LIST}
 
-def is_p2sh(currency, prefix):
-    return prefix == base58_prefix_map[currency][1]
 
 # Tagged field containing BitArray
 def tagged(char, l):
@@ -178,13 +164,10 @@ def pull_tagged(stream):
     return (CHARSET[tag], stream.read(length * 5), stream)
 
 def lnencode(addr: 'LnAddr', privkey) -> str:
-    # see https://github.com/lightningnetwork/lightning-rfc/pull/844
-    if constants.net.NET_NAME == "signet":
-        addr.currency = constants.net.BOLT11_HRP
     if addr.amount:
-        amount = addr.currency + shorten_amount(addr.amount)
+        amount = addr.net.BOLT11_HRP + shorten_amount(addr.amount)
     else:
-        amount = addr.currency if addr.currency else ''
+        amount = addr.net.BOLT11_HRP if addr.net else ''
 
     hrp = 'ln' + amount
 
@@ -221,7 +204,7 @@ def lnencode(addr: 'LnAddr', privkey) -> str:
             route = bitstring.BitArray(pubkey) + bitstring.pack('intbe:32', feebase) + bitstring.pack('intbe:32', feerate) + bitstring.pack('intbe:16', cltv)
             data += tagged('t', route)
         elif k == 'f':
-            data += encode_fallback(v, addr.currency)
+            data += encode_fallback(v, addr.net)
         elif k == 'd':
             # truncate to max length: 1024*5 bits = 639 bytes
             data += tagged_bytes('d', v.encode()[0:639])
@@ -270,7 +253,7 @@ def lnencode(addr: 'LnAddr', privkey) -> str:
 
 
 class LnAddr(object):
-    def __init__(self, *, paymenthash: bytes = None, amount=None, currency=None, tags=None, date=None,
+    def __init__(self, *, paymenthash: bytes = None, amount=None, net: Type[AbstractNet] = None, tags=None, date=None,
                  payment_secret: bytes = None):
         self.date = int(time.time()) if not date else int(date)
         self.tags = [] if not tags else tags
@@ -279,7 +262,7 @@ class LnAddr(object):
         self.payment_secret = payment_secret
         self.signature = None
         self.pubkey = None
-        self.currency = constants.net.SEGWIT_HRP if currency is None else currency
+        self.net = constants.net if net is None else net  # type: Type[AbstractNet]
         self._amount = amount  # type: Optional[Decimal]  # in bitcoins
         self._min_final_cltv_expiry = 18
 
@@ -330,7 +313,7 @@ class LnAddr(object):
     def __str__(self):
         return "LnAddr[{}, amount={}{} tags=[{}]]".format(
             hexlify(self.pubkey.serialize()).decode('utf-8') if self.pubkey else None,
-            self.amount, self.currency,
+            self.amount, self.net.BOLT11_HRP,
             ", ".join([k + '=' + str(v) for k, v in self.tags])
         )
 
@@ -367,12 +350,9 @@ class SerializableKey:
     def serialize(self):
         return self.pubkey.get_public_key_bytes(True)
 
-def lndecode(invoice: str, *, verbose=False, expected_hrp=None) -> LnAddr:
-    if expected_hrp is None:
-        expected_hrp = constants.net.SEGWIT_HRP
-    # see https://github.com/lightningnetwork/lightning-rfc/pull/844
-    if constants.net.NET_NAME == "signet":
-        expected_hrp = constants.net.BOLT11_HRP
+def lndecode(invoice: str, *, verbose=False, net=None) -> LnAddr:
+    if net is None:
+        net = constants.net
     decoded_bech32 = bech32_decode(invoice, ignore_long_length=True)
     hrp = decoded_bech32.hrp
     data = decoded_bech32.data
@@ -387,8 +367,8 @@ def lndecode(invoice: str, *, verbose=False, expected_hrp=None) -> LnAddr:
     if not hrp.startswith('ln'):
         raise ValueError("Does not start with ln")
 
-    if not hrp[2:].startswith(expected_hrp):
-        raise ValueError("Wrong Lightning invoice HRP " + hrp[2:] + ", should be " + expected_hrp)
+    if not hrp[2:].startswith(net.BOLT11_HRP):
+        raise ValueError(f"Wrong Lightning invoice HRP {hrp[2:]}, should be {net.BOLT11_HRP}")
 
     data = u5_to_bitarray(data)
 
@@ -403,7 +383,7 @@ def lndecode(invoice: str, *, verbose=False, expected_hrp=None) -> LnAddr:
 
     m = re.search("[^\\d]+", hrp[2:])
     if m:
-        addr.currency = m.group(0)
+        addr.net = BOLT11_HRP_INV_DICT[m.group(0)]
         amountstr = hrp[2+m.end():]
         # BOLT #11:
         #
@@ -453,7 +433,7 @@ def lndecode(invoice: str, *, verbose=False, expected_hrp=None) -> LnAddr:
                  s.read(16).uintbe)
             addr.tags.append(('t', e))
         elif tag == 'f':
-            fallback = parse_fallback(tagdata, addr.currency)
+            fallback = parse_fallback(tagdata, addr.net)
             if fallback:
                 addr.tags.append(('f', fallback))
             else:
@@ -532,13 +512,3 @@ def lndecode(invoice: str, *, verbose=False, expected_hrp=None) -> LnAddr:
         addr.pubkey = SerializableKey(ecc.ECPubkey.from_sig_string(sigdecoded[:64], sigdecoded[64], hrp_hash))
 
     return addr
-
-
-
-
-if __name__ == '__main__':
-    # run using
-    # python3 -m electrum.lnaddr <invoice> <expected hrp>
-    # python3 -m electrum.lnaddr lntb1n1pdlcakepp5e7rn0knl0gm46qqp9eqdsza2c942d8pjqnwa5903n39zu28sgk3sdq423jhxapqv3hkuct5d9hkucqp2rzjqwyx8nu2hygyvgc02cwdtvuxe0lcxz06qt3lpsldzcdr46my5epmj9vk9sqqqlcqqqqqqqlgqqqqqqgqjqdhnmkgahfaynuhe9md8k49xhxuatnv6jckfmsjq8maxta2l0trh5sdrqlyjlwutdnpd5gwmdnyytsl9q0dj6g08jacvthtpeg383k0sq542rz2 tb1n
-    import sys
-    print(lndecode(sys.argv[1], expected_hrp=sys.argv[2]))

electrum/lnworker.py

@@ -1398,7 +1398,7 @@ class LNWallet(LNWorker):
 
     @staticmethod
     def _check_invoice(invoice: str, *, amount_msat: int = None) -> LnAddr:
-        addr = lndecode(invoice, expected_hrp=constants.net.SEGWIT_HRP)
+        addr = lndecode(invoice)
         if addr.is_expired():
             raise InvoiceError(_("This invoice has expired"))
         if amount_msat:  # replace amt in invoice. main usecase is paying zero amt invoices

electrum/tests/test_bolt11.py

@@ -8,6 +8,7 @@ from electrum.lnaddr import shorten_amount, unshorten_amount, LnAddr, lnencode,
 from electrum.segwit_addr import bech32_encode, bech32_decode
 from electrum import segwit_addr
 from electrum.lnutil import UnknownEvenFeatureBits, derive_payment_secret_from_payment_preimage, LnFeatures
+from electrum import constants
 
 from . import ElectrumTestCase
 
@@ -69,7 +70,7 @@ class TestBolt11(ElectrumTestCase):
              "lnbc1m1ps9zprzpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsxqzpu9rflz25dx0qw6kdg05u0c5hdc30yq6ga6ew4pz86n244va45nchns9zrs3wjxznsqnt37hz7pswvc56wvuhxcjyd6k3lqf4ujynyxuspmvr078"),
             (LnAddr(date=timestamp, paymenthash=RHASH, amount=Decimal('1'), tags=[('h', longdescription)]),
              "lnbc11ps9zprzpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqs2qjafckq94q3js6lvqz2kmenn9ysjejyj8fm4hlx0xtqhaxfzlxjappkgp0hmm40dnuan4v3jy83lqjup2n0fdzgysg049y9l9uc98qq07kfd3"),
-            (LnAddr(date=timestamp, paymenthash=RHASH, currency='tb', tags=[('f', 'mk2QpYatsKicvFVuTAQLBryyccRXMUaGHP'), ('h', longdescription)]),
+            (LnAddr(date=timestamp, paymenthash=RHASH, net=constants.BitcoinTestnet, tags=[('f', 'mk2QpYatsKicvFVuTAQLBryyccRXMUaGHP'), ('h', longdescription)]),
              "lntb1ps9zprzpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqfpp3x9et2e20v6pu37c5d9vax37wxq72un98hp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsr9zktgu78k8p9t8555ve37qwfvqn6ga37fnfwhgexmf20nzdpmuhwvuv7zra3xrh8y2ggxxuemqfsgka9x7uzsrcx8rfv85c8pmhq9gq4sampn"),
             (LnAddr(date=timestamp, paymenthash=RHASH, amount=24, tags=[
                 ('r', [(unhexlify('029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255'), unhexlify('0102030405060708'), 1, 20, 3),
@@ -109,7 +110,7 @@ class TestBolt11(ElectrumTestCase):
         for lnaddr1, invoice_str1 in tests:
             invoice_str2 = lnencode(lnaddr1, PRIVKEY)
             self.assertEqual(invoice_str1, invoice_str2)
-            lnaddr2 = lndecode(invoice_str2, expected_hrp=lnaddr1.currency)
+            lnaddr2 = lndecode(invoice_str2, net=lnaddr1.net)
             self.compare(lnaddr1, lnaddr2)
 
     def test_n_decoding(self):
@@ -134,11 +135,11 @@ class TestBolt11(ElectrumTestCase):
 
     def test_min_final_cltv_expiry_decoding(self):
         lnaddr = lndecode("lnsb500u1pdsgyf3pp5nmrqejdsdgs4n9ukgxcp2kcq265yhrxd4k5dyue58rxtp5y83s3qdqqcqzystrggccm9yvkr5yqx83jxll0qjpmgfg9ywmcd8g33msfgmqgyfyvqhku80qmqm8q6v35zvck2y5ccxsz5avtrauz8hgjj3uahppyq20qp6dvwxe",
-                          expected_hrp="sb")
+                          net=constants.BitcoinSimnet)
         self.assertEqual(144, lnaddr.get_min_final_cltv_expiry())
 
         lnaddr = lndecode("lntb15u1p0m6lzupp5zqjthgvaad9mewmdjuehwddyze9d8zyxcc43zhaddeegt37sndgsdq4xysyymr0vd4kzcmrd9hx7cqp7xqrrss9qy9qsqsp5vlhcs24hwm747w8f3uau2tlrdkvjaglffnsstwyamj84cxuhrn2s8tut3jqumepu42azyyjpgqa4w9w03204zp9h4clk499y2umstl6s29hqyj8vv4as6zt5567ux7l3f66m8pjhk65zjaq2esezk7ll2kcpljewkg",
-                          expected_hrp="tb")
+                          net=constants.BitcoinTestnet)
         self.assertEqual(30, lnaddr.get_min_final_cltv_expiry())
 
     def test_min_final_cltv_expiry_roundtrip(self):

electrum/util.py

@@ -24,7 +24,7 @@ import binascii
 import os, sys, re, json
 from collections import defaultdict, OrderedDict
 from typing import (NamedTuple, Union, TYPE_CHECKING, Tuple, Optional, Callable, Any,
-                    Sequence, Dict, Generic, TypeVar, List, Iterable)
+                    Sequence, Dict, Generic, TypeVar, List, Iterable, Set)
 from datetime import datetime
 import decimal
 from decimal import Decimal
@@ -72,6 +72,14 @@ def inv_dict(d):
     return {v: k for k, v in d.items()}
 
 
+def all_subclasses(cls) -> Set:
+    """Return all (transitive) subclasses of cls."""
+    res = set(cls.__subclasses__())
+    for sub in res.copy():
+        res |= all_subclasses(sub)
+    return res
+
+
 ca_path = certifi.where()