ln feature bits: validate transitive feature deps everywhere

electrum/channel_db.py

@@ -39,7 +39,7 @@ from . import constants
 from .util import bh2u, profiler, get_headers_dir, bfh, is_ip_address, list_enabled_bits
 from .logging import Logger
 from .lnutil import (LNPeerAddr, format_short_channel_id, ShortChannelID,
-                     UnknownEvenFeatureBits, validate_features)
+                     validate_features, IncompatibleOrInsaneFeatures)
 from .lnverifier import LNChannelVerifier, verify_sig_for_channel_update
 from .lnmsg import decode_msg
 
@@ -331,8 +331,8 @@ class ChannelDB(SqlDB):
                 continue
             try:
                 channel_info = ChannelInfo.from_msg(msg)
-            except UnknownEvenFeatureBits:
-                self.logger.info("unknown feature bits")
+            except IncompatibleOrInsaneFeatures as e:
+                self.logger.info(f"unknown or insane feature bits: {e!r}")
                 continue
             if trusted:
                 added += 1
@@ -346,7 +346,7 @@ class ChannelDB(SqlDB):
     def add_verified_channel_info(self, msg: dict, *, capacity_sat: int = None) -> None:
         try:
             channel_info = ChannelInfo.from_msg(msg)
-        except UnknownEvenFeatureBits:
+        except IncompatibleOrInsaneFeatures:
             return
         channel_info = channel_info._replace(capacity_sat=capacity_sat)
         with self.lock:
@@ -499,7 +499,7 @@ class ChannelDB(SqlDB):
         for msg_payload in msg_payloads:
             try:
                 node_info, node_addresses = NodeInfo.from_msg(msg_payload)
-            except UnknownEvenFeatureBits:
+            except IncompatibleOrInsaneFeatures:
                 continue
             node_id = node_info.node_id
             # Ignore node if it has no associated channel (DoS protection)
@@ -593,11 +593,17 @@ class ChannelDB(SqlDB):
         self._recent_peers = sorted_node_ids[:self.NUM_MAX_RECENT_PEERS]
         c.execute("""SELECT * FROM channel_info""")
         for short_channel_id, msg in c:
-            ci = ChannelInfo.from_raw_msg(msg)
+            try:
+                ci = ChannelInfo.from_raw_msg(msg)
+            except IncompatibleOrInsaneFeatures:
+                continue
             self._channels[ShortChannelID.normalize(short_channel_id)] = ci
         c.execute("""SELECT * FROM node_info""")
         for node_id, msg in c:
-            node_info, node_addresses = NodeInfo.from_raw_msg(msg)
+            try:
+                node_info, node_addresses = NodeInfo.from_raw_msg(msg)
+            except IncompatibleOrInsaneFeatures:
+                continue
             # don't load node_addresses because they dont have timestamps
             self._nodes[node_id] = node_info
         c.execute("""SELECT * FROM policy""")

electrum/lnaddr.py

@@ -170,7 +170,7 @@ 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: 'LnAddr', privkey):
+def lnencode(addr: 'LnAddr', privkey) -> str:
     if addr.amount:
         amount = Decimal(str(addr.amount))
         # We can only send down to millisatoshi.

electrum/lnutil.py

@@ -165,7 +165,6 @@ class HandshakeFailed(LightningError): pass
 class ConnStringFormatError(LightningError): pass
 class UnknownPaymentHash(LightningError): pass
 class RemoteMisbehaving(LightningError): pass
-class UnknownEvenFeatureBits(Exception): pass
 
 class NotFoundChanAnnouncementForUpdate(Exception): pass
 
@@ -855,7 +854,11 @@ def get_ln_flag_pair_of_bit(flag_bit: int) -> int:
         return flag_bit - 1
 
 
-class IncompatibleLightningFeatures(ValueError): pass
+
+class IncompatibleOrInsaneFeatures(Exception): pass
+class UnknownEvenFeatureBits(IncompatibleOrInsaneFeatures): pass
+class IncompatibleLightningFeatures(IncompatibleOrInsaneFeatures): pass
+
 
 def ln_compare_features(our_features: 'LnFeatures', their_features: int) -> 'LnFeatures':
     """Returns negotiated features.
@@ -886,13 +889,17 @@ def ln_compare_features(our_features: 'LnFeatures', their_features: int) -> 'LnF
 
 
 def validate_features(features: int) -> None:
-    """Raises UnknownEvenFeatureBits if there is an unimplemented
-    mandatory feature.
+    """Raises IncompatibleOrInsaneFeatures if
+    - a mandatory feature is listed that we don't recognize, or
+    - the features are inconsistent
     """
+    features = LnFeatures(features)
     enabled_features = list_enabled_bits(features)
     for fbit in enabled_features:
         if (1 << fbit) & LN_FEATURES_IMPLEMENTED == 0 and fbit % 2 == 0:
             raise UnknownEvenFeatureBits(fbit)
+    if not features.validate_transitive_dependecies():
+        raise IncompatibleOrInsaneFeatures("not all transitive dependencies are set")
 
 
 def derive_payment_secret_from_payment_preimage(payment_preimage: bytes) -> bytes:

electrum/tests/test_bolt11.py

@@ -78,11 +78,11 @@ class TestBolt11(ElectrumTestCase):
             LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 514)]),
             LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 8))]),
             LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 9))]),
-            LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 11))]),
+            LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 7) + (1 << 11))]),
             LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 12))]),
             LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 13))]),
-            LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 14))]),
-            LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 15))]),
+            LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 9) + (1 << 14))]),
+            LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 10 + (1 << 9) + (1 << 15))]),
             LnAddr(paymenthash=RHASH, amount=24, tags=[('h', longdescription), ('9', 33282)], payment_secret=b"\x11" * 32),
         ]
 
@@ -128,8 +128,8 @@ class TestBolt11(ElectrumTestCase):
             lndecode("lnbc25m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5vdhkven9v5sxyetpdees9q4pqqqqqqqqqqqqqqqqqqszk3ed62snp73037h4py4gry05eltlp0uezm2w9ajnerhmxzhzhsu40g9mgyx5v3ad4aqwkmvyftzk4k9zenz90mhjcy9hcevc7r3lx2sphzfxz7")
 
     def test_payment_secret(self):
-        lnaddr = lndecode("lnbc25m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5vdhkven9v5sxyetpdeessp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygs9q5sqqqqqqqqqqqqqqqpqqq4u9s93jtgysm3mrwll70zr697y3mf902hvxwej0v7c62rsltw83ng0pu8w3j230sluc5gxkdmm9dvpy9y6ggtjd2w544mzdrcs42t7sqdkcy8h")
-        self.assertEqual((1 << 15) + (1 << 99) , lnaddr.get_tag('9'))
+        lnaddr = lndecode("lnbc25m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqsp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygsdq5vdhkven9v5sxyetpdees9q5sqqqqqqqqqqqqqqqpqsqvvh7ut50r00p3pg34ea68k7zfw64f8yx9jcdk35lh5ft8qdr8g4r0xzsdcrmcy9hex8un8d8yraewvhqc9l0sh8l0e0yvmtxde2z0hgpzsje5l")
+        self.assertEqual((1 << 9) + (1 << 15) + (1 << 99), lnaddr.get_tag('9'))
         self.assertEqual(b"\x11" * 32, lnaddr.payment_secret)
 
     def test_derive_payment_secret_from_payment_preimage(self):