[UTXO-BUG] fix bridge_api validate_chain_address_format — ethereum chain accepted any string

node/bridge_api.py

@@ -22,6 +22,7 @@
 import os
 import re
 from typing import Optional, Tuple, Dict, Any
+from Crypto.Hash import keccak as _keccak
 from decimal import Decimal, InvalidOperation
 from dataclasses import dataclass
 from enum import Enum
@@ -119,6 +120,14 @@ class ValidationResult:
 VALID_BRIDGE_TYPES = {"bottube", "internal", "custom"}
 
 
+def _eip55_checksum(address_hex: str) -> str:
+    """Return the EIP-55 checksummed form of a lowercase 40-char hex address."""
+    k = _keccak.new(digest_bits=256)
+    k.update(address_hex.encode("ascii"))
+    h = k.hexdigest()
+    return "".join(c.upper() if int(h[i], 16) >= 8 else c for i, c in enumerate(address_hex))
+
+
 def validate_bridge_request(data: Optional[Dict]) -> ValidationResult:
     """Validate bridge transfer request payload."""
     if not data:
@@ -268,7 +277,22 @@ def validate_chain_address_format(chain: str, address: str) -> Tuple[bool, str]:
             return False, "Invalid Base address length"
         if not all(char in "0123456789abcdefABCDEF" for char in address[2:]):
             return False, "Invalid Base address hex"
-
+
+    elif chain == "ethereum":
+        # Ethereum addresses: 0x + 40 hex chars.
+        # All-lowercase and all-uppercase are accepted without checksum.
+        # Mixed-case must satisfy EIP-55 checksum to catch typos in payout addresses.
+        if not address.startswith("0x"):
+            return False, "Ethereum addresses must start with '0x'"
+        if len(address) != 42:
+            return False, "Invalid Ethereum address length"
+        hex_part = address[2:]
+        if not all(char in "0123456789abcdefABCDEF" for char in hex_part):
+            return False, "Invalid Ethereum address hex"
+        is_mixed = any(c.islower() for c in hex_part) and any(c.isupper() for c in hex_part)
+        if is_mixed and address[2:] != _eip55_checksum(hex_part.lower()):
+            return False, "Mixed-case Ethereum address fails EIP-55 checksum — use all-lowercase or a valid checksummed address"
+
     return True, ""
 
 

node/test_bridge_ethereum_address_poc.py

@@ -0,0 +1,77 @@
+"""
+PoC: validate_chain_address_format accepted any non-empty string >= 10 chars
+for the 'ethereum' chain because no elif branch existed.
+
+Before fix: validate_chain_address_format("ethereum", "garbage123") -> (True, "")
+After fix:  validate_chain_address_format("ethereum", "garbage123") -> (False, "...")
+"""
+import unittest
+
+try:
+    from bridge_api import validate_chain_address_format
+except ImportError:
+    import sys
+    import os
+    sys.path.insert(0, os.path.dirname(__file__))
+    from bridge_api import validate_chain_address_format
+
+
+class TestBridgeEthereumAddressValidation(unittest.TestCase):
+
+    # --- rejection cases (all were previously accepted) ---
+
+    def test_rejects_garbage_string(self):
+        ok, msg = validate_chain_address_format("ethereum", "garbage1234567890")
+        self.assertFalse(ok, "Garbage string must be rejected")
+
+    def test_rejects_missing_0x_prefix(self):
+        ok, msg = validate_chain_address_format("ethereum", "aabbccddeeff00112233445566778899aabbccdd")
+        self.assertFalse(ok)
+        self.assertIn("0x", msg)
+
+    def test_rejects_wrong_length(self):
+        ok, msg = validate_chain_address_format("ethereum", "0xdeadbeef")
+        self.assertFalse(ok)
+
+    def test_rejects_non_hex_chars(self):
+        ok, msg = validate_chain_address_format("ethereum", "0x" + "g" * 40)
+        self.assertFalse(ok)
+
+    def test_rejects_empty(self):
+        ok, msg = validate_chain_address_format("ethereum", "")
+        self.assertFalse(ok)
+
+    # --- acceptance cases ---
+
+    def test_accepts_valid_lowercase(self):
+        ok, _ = validate_chain_address_format("ethereum", "0x" + "a" * 40)
+        self.assertTrue(ok)
+
+    def test_accepts_valid_eip55_checksum(self):
+        # EIP-55 checksummed address — mixed-case must match keccak-derived checksum
+        ok, _ = validate_chain_address_format("ethereum", "0xabCDEF1234567890ABcDEF1234567890aBCDeF12")
+        self.assertTrue(ok)
+
+    def test_rejects_invalid_mixed_case(self):
+        # Typo'd mixed-case that does not satisfy EIP-55 checksum
+        ok, msg = validate_chain_address_format("ethereum", "0xAbCdEf1234567890AbCdEf1234567890AbCdEf12")
+        self.assertFalse(ok)
+        self.assertIn("EIP-55", msg)
+
+    def test_accepts_zero_address(self):
+        ok, _ = validate_chain_address_format("ethereum", "0x" + "0" * 40)
+        self.assertTrue(ok)
+
+    # --- other chains unaffected ---
+
+    def test_base_still_validated(self):
+        ok, msg = validate_chain_address_format("base", "not-an-address")
+        self.assertFalse(ok)
+
+    def test_rustchain_unaffected(self):
+        ok, _ = validate_chain_address_format("rustchain", "RTC" + "a" * 40)
+        self.assertTrue(ok)
+
+
+if __name__ == "__main__":
+    unittest.main()