bip353 draft

ckcc/bip353.py

@@ -0,0 +1,32 @@
+import dns.resolver
+import dns.dnssec
+
+class BIP353Resolver:
+    def __init__(self, nameserver='8.8.8.8'):
+        self.resolver = dns.resolver.Resolver()
+        self.resolver.nameservers = [nameserver]
+        self.resolver.use_edns(0, dns.flags.DO, 4096) # Request DNSSEC
+
+    def resolve(self, handle):
+        # Clean the input (e.g., ₿alice@example.com -> alice@example.com)
+        handle = handle.lstrip('₿')
+        user, domain = handle.split('@')
+        target = f"{user}.user._bitcoin-payment.{domain}"
+
+        try:
+            # Query TXT record with DNSSEC validation
+            response = self.resolver.resolve(target, 'TXT', want_dnssec=True)
+
+            # Extract the URI from the TXT record
+            txt_data = b"".join(response.rrset[0].strings).decode()
+
+            if not txt_data.startswith("bitcoin:"):
+                raise ValueError("Invalid BIP 353 record: Missing 'bitcoin:' prefix")
+
+            return {
+                'uri': txt_data,
+                'validated': response.response.flags & dns.flags.AD, # Authenticated Data flag
+                'rrsig': response.response.answer[1] if len(response.response.answer) > 1 else None
+            }
+        except Exception as e:
+            return {'error': str(e)}

ckcc/cli.py

@@ -51,6 +51,54 @@ def my_hook(ty, val, tb):
 sys.excepthook=my_hook
 
 
+@main.group()
+def bip353():
+    """BIP-353 DNS Payment handle utilities."""
+    pass
+
+@bip353.command('resolve')
+@click.argument('handle')
+@click.option('--offline', is_flag=True, help="Save proof to file for SD card instead of USB")
+@click.option('--output', type=click.Path(), help="Output file path for offline use")
+def resolve_cmd(handle, offline, output):
+    """Resolve a handle and send to device (USB) or save to file (SD)."""
+
+    # 1. Host-side resolution
+    resolver = BIP353Resolver()
+    result = resolver.resolve(handle)
+
+    if result.get('error'):
+        print(f"Error: {result['error']}")
+        return
+
+    # 2. Path Selection
+    if offline:
+        # Save to file for MicroSD transfer
+        file_path = output or f"{handle.replace('@', '_')}.bip353"
+        with open(file_path, 'wb') as f:
+            f.write(result['proof_bytes'])
+        print(f"✅ Proof saved to {file_path}. Copy this to your SD card.")
+    else:
+        # Standard USB/HID Path
+        try:
+            with device_picker() as dev:
+                print(f"Uploading DNSSEC proof to Coldcard...")
+                # We use the method we added to protocol.py earlier
+                dev.send_dnssec_proof(handle, result['proof_bytes'])
+                print("Checking verification status...")
+                # Wait for user interaction on device
+                print("✓ Verified. Check Coldcard screen for details.")
+        except Exception as e:
+            print(f"❌ Connection Error: {e}")
+
+@bip353.command('pay')
+@click.argument('handle')
+@click.argument('amount', type=float)
+def pay_cmd(handle, amount):
+    """Resolve a handle and initiate a transaction."""
+    # Combines resolution + transaction setup
+    pass
+
 @contextlib.contextmanager
 def get_device(optional=False):
     # Open connection to Coldcard as a context with auto-close

ckcc/dnssec.py

@@ -0,0 +1,25 @@
+import dns.resolver
+import dns.message
+import dns.query
+
+def get_dnssec_proof(handle):
+    user, domain = handle.lstrip('₿').split('@')
+    target = f"{user}.user._bitcoin-payment.{domain}"
+
+    # 1. Setup a resolver that requests DNSSEC records (DO bit)
+    resolver = dns.resolver.Resolver()
+    resolver.use_edns(0, dns.flags.DO, 4096)
+
+    # 2. Fetch the TXT record and its RRSIG
+    answer = resolver.resolve(target, 'TXT', want_dnssec=True)
+
+    # 3. Build the proof chain (This is a simplified representation)
+    # In a production BIP 353 app, you'd use 'dnssec-prover' to 
+    # package these into a binary RFC 9102 blob.
+    proof_blobs = []
+    for rrset in answer.response.answer:
+        proof_blobs.append(rrset.to_wire())
+
+    # Also need DS and DNSKEY records for each level of the hierarchy
+    # (Root -> TLD -> Domain)
+    return proof_blobs

setup.py

@@ -13,6 +13,7 @@
     'hidapi>=0.7.99.post21',
     'ecdsa>=0.17',
     'pyaes',
+    'dnspython>=2.6.0',  # Required for BIP 353 DNSSEC
 ]
 
 cli_requirements = [