trying to implement a working pkarr client in python

lookup.py

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+#!/usr/bin/env python3
+
+import asyncio
+import time
+import logging
+from argparse import ArgumentParser
+from src.client import PkarrClient
+from src.public_key import PublicKey
+from src.keypair import Keypair
+from src.errors import PkarrError
+import bencodepy
+
+
+DEFAULT_MINIMUM_TTL = 300  # 5 minutes
+DEFAULT_MAXIMUM_TTL = 24 * 60 * 60  # 24 hours
+DEFAULT_BOOTSTRAP_NODES = [
+    "router.bittorrent.com:6881",
+    "router.utorrent.com:6881",
+    "dht.transmissionbt.com:6881",
+    "dht.libtorrent.org:25401"
+]
+
+logging.basicConfig(level=logging.DEBUG, format='%(asctime)s - %(levelname)s - %(message)s')
+
+async def resolve(client: PkarrClient, public_key: PublicKey):
+    start_time = time.time()
+    try:
+        signed_packet = await client.lookup(public_key.to_z32(), max_attempts=200, timeout=60)
+        elapsed = time.time() - start_time
+
+        if signed_packet:
+            print(f"\nResolved in {int(elapsed * 1000)} milliseconds SignedPacket ({public_key.to_z32()}):")
+            print(f"    last_seen: {signed_packet.elapsed()} seconds ago")
+            print(f"    timestamp: {signed_packet.timestamp},")
+            print(f"    signature: {signed_packet.signature.hex().upper()}")
+            print("    records:")
+            for rr in signed_packet.packet.answers:
+                print(f"        {rr}")
+        else:
+            print(f"\nFailed to resolve {public_key.to_z32()}")
+    except PkarrError as e:
+        print(f"Got error: {e}")
+
+
+async def main():
+    parser = ArgumentParser(description="Resolve Pkarr records")
+    parser.add_argument("public_key", help="z-base-32 encoded public key")
+    parser.add_argument("--bootstrap", nargs='+', default=DEFAULT_BOOTSTRAP_NODES,
+                        help="Bootstrap nodes (default: %(default)s)")
+    args = parser.parse_args()
+
+    try:
+        public_key = PublicKey(args.public_key)
+    except PkarrError as e:
+        logging.error(f"Invalid public key: {e}")
+        return
+
+    keypair = Keypair.random()
+    client = PkarrClient(keypair, args.bootstrap)
+
+    logging.info(f"Resolving Pkarr: {args.public_key}")
+    logging.info("\n=== COLD LOOKUP ===")
+    await resolve(client, public_key)
+
+    await asyncio.sleep(1)
+
+    logging.info("\n=== SUBSEQUENT LOOKUP ===")
+    await resolve(client, public_key)
+
+if __name__ == "__main__":
+    asyncio.run(main())

src/client.py

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+import asyncio
+import random
+from typing import List, Optional, Union
+from .signed_packet import SignedPacket
+from .keypair import Keypair
+from .public_key import PublicKey
+from .resource_record import ResourceRecord
+from .packet import Packet
+from .errors import PkarrError
+import logging
+import socket
+import struct
+import hashlib
+import bencodepy
+import json
+import time
+
+logging.basicConfig(level=logging.DEBUG)
+
+class PkarrClient:
+    def __init__(self, keypair: Keypair, bootstrap_nodes: List[str]):
+        self.keypair = keypair
+        self.bootstrap_nodes = bootstrap_nodes
+        self.known_nodes = set(bootstrap_nodes)
+
+    async def lookup(self, public_key: str, max_attempts: int = 100, timeout: int = 30) -> Optional[SignedPacket]:
+        """Look up records from the DHT."""
+        target_key = PublicKey(public_key)
+        
+        # Check cache first
+        cached_packet, expiration_time = self.cache.get(public_key, (None, 0))
+        if cached_packet and time.time() < expiration_time:
+            logging.debug(f"Have fresh signed_packet in cache. expires_in={int(expiration_time - time.time())}")
+            return cached_packet
+
+        nodes_to_query = set(self.bootstrap_nodes)
+        queried_nodes = set()
+        
+        start_time = time.time()
+        attempts = 0
+
+        while nodes_to_query and attempts < max_attempts and (time.time() - start_time) < timeout:
+            node = nodes_to_query.pop()
+            queried_nodes.add(node)
+            attempts += 1
+            
+            logging.info(f"Attempt {attempts}: Querying node {node}")
+            
+            try:
+                result = await self._request_packet(node, target_key)
+                if isinstance(result, SignedPacket):
+                    logging.info(f"Found result after {attempts} attempts and {time.time() - start_time:.2f} seconds")
+                    # Cache the result
+                    self.cache[public_key] = (result, time.time() + result.ttl(DEFAULT_MINIMUM_TTL, DEFAULT_MAXIMUM_TTL))
+                    return result
+                elif result:
+                    new_nodes = set(result) - queried_nodes
+                    nodes_to_query.update(new_nodes)
+                    logging.info(f"Added {len(new_nodes)} new nodes to query. Total known nodes: {len(self.known_nodes)}")
+            except PkarrError as e:
+                logging.error(f"Error with node {node}: {e}")
+        
+        logging.info(f"Lookup completed after {attempts} attempts and {time.time() - start_time:.2f} seconds")
+        logging.info(f"Queried {len(queried_nodes)} unique nodes")
+        
+        if attempts >= max_attempts:
+            logging.warning("Lookup terminated: maximum attempts reached")
+        elif (time.time() - start_time) >= timeout:
+            logging.warning("Lookup terminated: timeout reached")
+        else:
+            logging.warning("Lookup terminated: no more nodes to query")
+        
+        return None
+
+    async def _request_packet(self, node: str, target_key: PublicKey, record_type: str) -> Optional[Union[SignedPacket, List[str]]]:
+        """Request a packet from a node."""
+        logging.info(f"Requesting packet from node {node} for key {target_key.to_z32()} and record_type {record_type}")
+        
+        try:
+            # Extract IP and port from the node string
+            if '@' in node:
+                _, ip_port = node.split('@')
+            else:
+                ip_port = node
+            
+            host, port = ip_port.split(':')
+            port = int(port)
+
+            sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+            sock.settimeout(5)  # Set a 5-second timeout
+
+            # Ensure we have a 20-byte node ID
+            node_id = hashlib.sha1(self.keypair.public_key.to_bytes()).digest()
+
+            # Ensure we have a 20-byte info_hash
+            info_hash = hashlib.sha1(target_key.to_bytes()).digest()
+
+            # Prepare and send the DHT query
+            transaction_id = random.randint(0, 65535).to_bytes(2, 'big')
+            message = bencodepy.encode({
+                't': transaction_id,
+                'y': 'q',
+                'q': 'get_peers',
+                'a': {
+                    'id': node_id,
+                    'info_hash': info_hash
+                }
+            })
+
+            logging.debug(f"Sending message to {host}:{port}: {message}")
+            sock.sendto(message, (host, port))
+
+            # Wait for the response
+            data, addr = sock.recvfrom(1024)
+            logging.debug(f"Received raw response from {addr}: {data}")
+            
+            # Parse the response
+            response = bencodepy.decode(data)
+            human_readable = self._decode_response(response)
+            logging.info(f"Decoded response from {addr}:\n{json.dumps(human_readable, indent=2)}")
+            
+            if response.get(b'y') == b'e':
+                error_code, error_message = response.get(b'e', [None, b''])[0], response.get(b'e', [None, b''])[1].decode('utf-8', errors='ignore')
+                logging.error(f"Received error response: Code {error_code}, Message: {error_message}")
+                return None
+            
+            # Check if the response contains the data we need
+            if b'r' in response:
+                r = response[b'r']
+                if b'values' in r:
+                    # Process peer values
+                    peer_values = r[b'values']
+                    logging.info(f"Found {len(peer_values)} peer values")
+                    return await self._connect_to_peers(peer_values, target_key, record_type)
+                elif b'nodes' in r:
+                    # Process nodes for further querying
+                    nodes = r[b'nodes']
+                    decoded_nodes = self._decode_nodes(nodes)
+                    logging.info(f"Found {len(decoded_nodes)} nodes")
+                    self._update_known_nodes(decoded_nodes)
+                    return decoded_nodes
+            
+            return None
+
+        except socket.timeout:
+            logging.error(f"Timeout while connecting to {host}:{port}")
+        except Exception as e:
+            logging.error(f"Error requesting packet from {host}:{port}: {e}")
+            logging.exception("Exception details:")
+        finally:
+            sock.close()
+
+        return None
+
+    async def _connect_to_peers(self, peer_values: List[bytes], target_key: PublicKey, record_type: str) -> Optional[SignedPacket]:
+        """Connect to peers and try to retrieve the SignedPacket."""
+        for peer_value in peer_values:
+            try:
+                ip = socket.inet_ntoa(peer_value[:4])
+                port = struct.unpack("!H", peer_value[4:])[0]
+                peer = f"{ip}:{port}"
+                
+                logging.info(f"Connecting to peer {peer}")
+                
+                # Here you would implement the logic to connect to the peer and retrieve the SignedPacket
+                # For now, we'll just return a dummy SignedPacket
+                return SignedPacket(target_key, b"dummy_signature", Packet())
+            
+            except Exception as e:
+                logging.error(f"Error connecting to peer {peer}: {e}")
+        
+        return None
+
+
+    def _decode_response(self, response: dict[bytes, any]) -> dict[str, any]:
+        """Decode the bencoded response into a human-readable format."""
+        decoded = {}
+        for key, value in response.items():
+            str_key = key.decode('utf-8')
+            if isinstance(value, bytes):
+                try:
+                    decoded[str_key] = value.decode('utf-8')
+                except UnicodeDecodeError:
+                    decoded[str_key] = value.hex()
+            elif isinstance(value, dict):
+                decoded[str_key] = self._decode_response(value)
+            elif isinstance(value, list):
+                decoded[str_key] = [self._decode_response(item) if isinstance(item, dict) else item.hex() if isinstance(item, bytes) else item for item in value]
+            else:
+                decoded[str_key] = value
+
+        if 'r' in decoded and 'nodes' in decoded['r']:
+            decoded['r']['decoded_nodes'] = self._decode_nodes(response[b'r'][b'nodes'])
+
+        return decoded
+
+    def _decode_nodes(self, nodes_data: bytes) -> List[str]:
+        """Decode the compact node info."""
+        nodes = []
+        for i in range(0, len(nodes_data), 26):
+            node_id = nodes_data[i:i+20].hex()
+            ip = socket.inet_ntoa(nodes_data[i+20:i+24])
+            port = struct.unpack("!H", nodes_data[i+24:i+26])[0]
+            nodes.append(f"{ip}:{port}")
+        return nodes
+
+    def _update_known_nodes(self, new_nodes: List[str]) -> None:
+        """Update the list of known nodes."""
+        self.known_nodes.update(new_nodes)
+        logging.info(f"Updated known nodes. Total known nodes: {len(self.known_nodes)}")
+
+    async def _send_packet(self, node: str, signed_packet: SignedPacket) -> None:
+        """Send a signed packet to a node."""
+        # Implement UDP packet sending logic here
+        pass
+
+    async def maintain_network(self) -> None:
+        """Periodically maintain the network by pinging known nodes and discovering new ones."""
+        while True:
+            # Implement node discovery and maintenance logic here
+            await asyncio.sleep(60)  # Run maintenance every 60 seconds

src/crypto.py

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+import os
+import hashlib
+import ed25519
+
+class Crypto:
+    @staticmethod
+    def generate_keypair():
+        private_key, public_key = ed25519.create_keypair()
+        return private_key.to_bytes()[:32], public_key.to_bytes()
+
+    @staticmethod
+    def derive_public_key(secret_key):
+        if len(secret_key) != 32:
+            raise ValueError("Secret key must be 32 bytes long")
+        signing_key = ed25519.SigningKey(secret_key)
+        return signing_key.get_verifying_key().to_bytes()
+
+    @staticmethod
+    def sign(secret_key, message):
+        if len(secret_key) != 32:
+            raise ValueError("Secret key must be 32 bytes long")
+        signing_key = ed25519.SigningKey(secret_key)
+        return signing_key.sign(message)
+
+    @staticmethod
+    def verify(public_key, message, signature):
+        verifying_key = ed25519.VerifyingKey(public_key)
+        try:
+            verifying_key.verify(signature, message)
+            return True
+        except ed25519.BadSignatureError:
+            return False
+
+    @staticmethod
+    def hash(data):
+        return hashlib.sha256(data).digest()
+
+    @staticmethod
+    def random_bytes(length):
+        return os.urandom(length)
+
+    @staticmethod
+    def z_base_32_encode(data):
+        alphabet = "ybndrfg8ejkmcpqxot1uwisza345h769"
+        result = ""
+        bits = 0
+        value = 0
+        for byte in data:
+            value = (value << 8) | byte
+            bits += 8
+            while bits >= 5:
+                bits -= 5
+                result += alphabet[(value >> bits) & 31]
+        if bits > 0:
+            result += alphabet[(value << (5 - bits)) & 31]
+        return result
+
+    @staticmethod
+    def z_base_32_decode(encoded):
+        alphabet = "ybndrfg8ejkmcpqxot1uwisza345h769"
+        alphabet_map = {char: index for index, char in enumerate(alphabet)}
+        result = bytearray()
+        bits = 0
+        value = 0
+        for char in encoded:
+            value = (value << 5) | alphabet_map[char]
+            bits += 5
+            if bits >= 8:
+                bits -= 8
+                result.append((value >> bits) & 255)
+        return bytes(result)

src/dns_utils.py

@@ -0,0 +1,91 @@
+import struct
+from typing import List, Tuple
+from dns import message, name, rdata, rdatatype, rdataclass
+from .errors import DNSError
+
+def create_dns_query(domain: str, record_type: str) -> bytes:
+    """Create a DNS query packet."""
+    try:
+        qname = name.from_text(domain)
+        q = message.make_query(qname, rdatatype.from_text(record_type))
+        return q.to_wire()
+    except Exception as e:
+        raise DNSError(f"Failed to create DNS query: {str(e)}")
+
+def parse_dns_response(response: bytes) -> List[Tuple[str, str, int, str]]:
+    """Parse a DNS response and return a list of (name, type, ttl, data) tuples."""
+    try:
+        msg = message.from_wire(response)
+        results = []
+        for rrset in msg.answer:
+            name = rrset.name.to_text()
+            ttl = rrset.ttl
+            for rr in rrset:
+                rr_type = rdatatype.to_text(rr.rdtype)
+                rr_data = rr.to_text()
+                results.append((name, rr_type, ttl, rr_data))
+        return results
+    except Exception as e:
+        raise DNSError(f"Failed to parse DNS response: {str(e)}")
+
+def compress_domain_name(domain: str) -> bytes:
+    """Compress a domain name according to DNS name compression rules."""
+    try:
+        n = name.from_text(domain)
+        return n.to_wire()
+    except Exception as e:
+        raise DNSError(f"Failed to compress domain name: {str(e)}")
+
+def decompress_domain_name(compressed: bytes, offset: int = 0) -> Tuple[str, int]:
+    """Decompress a domain name from DNS wire format."""
+    try:
+        n, offset = name.from_wire(compressed, offset)
+        return n.to_text(), offset
+    except Exception as e:
+        raise DNSError(f"Failed to decompress domain name: {str(e)}")
+
+def encode_resource_record(name: str, rr_type: str, rr_class: str, ttl: int, rdata: str) -> bytes:
+    """Encode a resource record into DNS wire format."""
+    try:
+        n = name.from_text(name)
+        rr_type = rdatatype.from_text(rr_type)
+        rr_class = rdataclass.from_text(rr_class)
+        rd = rdata.from_text(rr_type, rr_class, rdata)
+        return (n.to_wire() + 
+                struct.pack("!HHIH", rr_type, rr_class, ttl, len(rd.to_wire())) + 
+                rd.to_wire())
+    except Exception as e:
+        raise DNSError(f"Failed to encode resource record: {str(e)}")
+
+def decode_resource_record(wire: bytes, offset: int = 0) -> Tuple[str, str, str, int, str, int]:
+    """Decode a resource record from DNS wire format."""
+    try:
+        n, offset = name.from_wire(wire, offset)
+        rr_type, rr_class, ttl, rdlen = struct.unpack_from("!HHIH", wire, offset)
+        offset += 10
+        rd = rdata.from_wire(rdatatype.to_text(rr_type), wire, offset, rdlen)
+        offset += rdlen
+        return (n.to_text(), 
+                rdatatype.to_text(rr_type), 
+                rdataclass.to_text(rr_class), 
+                ttl, 
+                rd.to_text(), 
+                offset)
+    except Exception as e:
+        raise DNSError(f"Failed to decode resource record: {str(e)}")
+
+def is_valid_domain_name(domain: str) -> bool:
+    """Check if a given string is a valid domain name."""
+    try:
+        name.from_text(domain)
+        return True
+    except Exception:
+        return False
+
+def normalize_domain_name(domain: str) -> str:
+    """Normalize a domain name (convert to lowercase and ensure it ends with a dot)."""
+    try:
+        n = name.from_text(domain)
+        return n.to_text().lower()
+    except Exception as e:
+        raise DNSError(f"Failed to normalize domain name: {str(e)}")

src/errors.py

@@ -0,0 +1,52 @@
+class PkarrError(Exception):
+    """Base class for all pkarr-related errors."""
+    pass
+
+class KeypairError(PkarrError):
+    """Raised when there's an issue with keypair operations."""
+    pass
+
+class PublicKeyError(PkarrError):
+    """Raised when there's an issue with public key operations."""
+    pass
+
+class SignatureError(PkarrError):
+    """Raised when there's an issue with signature operations."""
+    pass
+
+class PacketError(PkarrError):
+    """Raised when there's an issue with packet operations."""
+    pass
+
+class DNSError(PkarrError):
+    """Raised when there's an issue with DNS operations."""
+    pass
+
+class DHTError(PkarrError):
+    """Raised when there's an issue with DHT operations."""
+    pass
+
+class InvalidSignedPacketBytesLength(PacketError):
+    """Raised when the SignedPacket bytes length is invalid."""
+    def __init__(self, length: int):
+        super().__init__(f"Invalid SignedPacket bytes length, expected at least 104 bytes but got: {length}")
+
+class InvalidRelayPayloadSize(PacketError):
+    """Raised when the relay payload size is invalid."""
+    def __init__(self, size: int):
+        super().__init__(f"Invalid relay payload size, expected at least 72 bytes but got: {size}")
+
+class PacketTooLarge(PacketError):
+    """Raised when the DNS packet is too large."""
+    def __init__(self, size: int):
+        super().__init__(f"DNS Packet is too large, expected max 1000 bytes but got: {size}")
+
+class DHTIsShutdown(DHTError):
+    """Raised when the DHT is shutdown."""
+    def __init__(self):
+        super().__init__("DHT is shutdown")
+
+class PublishInflight(DHTError):
+    """Raised when a publish query is already in flight for the same public key."""
+    def __init__(self):
+        super().__init__("Publish query is already in flight for the same public_key")

src/keypair.py

@@ -0,0 +1,44 @@
+from .public_key import PublicKey
+from .crypto import Crypto
+from .errors import KeypairError
+
+class Keypair:
+    def __init__(self, secret_key: bytes):
+        if len(secret_key) != 32:
+            raise KeypairError(f"Secret key must be 32 bytes long, got {len(secret_key)} bytes")
+        self.secret_key = secret_key
+        self.public_key = PublicKey(Crypto.derive_public_key(secret_key))
+
+    @classmethod
+    def random(cls) -> 'Keypair':
+        """Generate a new random keypair."""
+        secret_key, _ = Crypto.generate_keypair()
+        return cls(secret_key)
+
+    @classmethod
+    def from_secret_key(cls, secret_key: bytes) -> 'Keypair':
+        """Create a Keypair from a secret key."""
+        return cls(secret_key)
+
+    def sign(self, message: bytes) -> bytes:
+        """Sign a message using this keypair."""
+        return Crypto.sign(self.secret_key, message)
+
+    def verify(self, message: bytes, signature: bytes) -> bool:
+        """Verify a signature using this keypair's public key."""
+        return self.public_key.verify(message, signature)
+
+    def to_bytes(self) -> bytes:
+        """Return the secret key bytes."""
+        return self.secret_key
+
+    @classmethod
+    def from_bytes(cls, secret_key: bytes) -> 'Keypair':
+        """Create a Keypair from bytes."""
+        return cls(secret_key)
+
+    def __str__(self):
+        return f"Keypair(public_key={self.public_key})"
+
+    def __repr__(self):
+        return self.__str__()

src/packet.py

@@ -0,0 +1,95 @@
+from dataclasses import dataclass, field
+from typing import List, Optional
+from dns import message, name, rdata, rdatatype, rdataclass
+from .resource_record import ResourceRecord
+from .errors import PacketError
+
+@dataclass
+class Packet:
+    answers: List[ResourceRecord] = field(default_factory=list)
+    id: int = 0
+    qr: bool = True  # True for response, False for query
+    opcode: int = 0  # 0 for standard query
+    aa: bool = True  # Authoritative Answer
+    tc: bool = False  # TrunCation
+    rd: bool = False  # Recursion Desired
+    ra: bool = False  # Recursion Available
+    z: int = 0  # Reserved for future use
+    rcode: int = 0  # Response code
+
+    @classmethod
+    def new_reply(cls, id: int):
+        return cls(answers=[], id=id)
+
+    def add_answer(self, answer: ResourceRecord):
+        self.answers.append(answer)
+
+    def build_bytes_vec_compressed(self) -> bytes:
+        """Build a compressed DNS wire format representation of the packet."""
+        try:
+            msg = message.Message(id=self.id)
+            msg.flags = 0
+            if self.qr:
+                msg.flags |= 1 << 15
+            msg.flags |= (self.opcode & 0xF) << 11
+            if self.aa:
+                msg.flags |= 1 << 10
+            if self.tc:
+                msg.flags |= 1 << 9
+            if self.rd:
+                msg.flags |= 1 << 8
+            if self.ra:
+                msg.flags |= 1 << 7
+            msg.flags |= (self.z & 0x7) << 4
+            msg.flags |= self.rcode & 0xF
+
+            for rr in self.answers:
+                rr_name = name.from_text(rr.name)
+                rr_ttl = rr.ttl
+                rr_rdataclass = rdataclass.from_text(rr.rclass)
+                rr_rdatatype = rdatatype.from_text(rr.rtype)
+                rr_rdata = rdata.from_text(rr_rdataclass, rr_rdatatype, rr.rdata)
+                msg.answer.append((rr_name, rr_ttl, rr_rdata))
+
+            return msg.to_wire()
+        except Exception as e:
+            raise PacketError(f"Failed to build packet: {str(e)}")
+
+    @classmethod
+    def from_bytes(cls, data: bytes) -> 'Packet':
+        """Create a Packet object from DNS wire format bytes."""
+        try:
+            msg = message.from_wire(data)
+            packet = cls(
+                id=msg.id,
+                qr=bool(msg.flags & (1 << 15)),
+                opcode=(msg.flags >> 11) & 0xF,
+                aa=bool(msg.flags & (1 << 10)),
+                tc=bool(msg.flags & (1 << 9)),
+                rd=bool(msg.flags & (1 << 8)),
+                ra=bool(msg.flags & (1 << 7)),
+                z=(msg.flags >> 4) & 0x7,
+                rcode=msg.flags & 0xF
+            )
+
+            for rrset in msg.answer:
+                for rr in rrset:
+                    resource_record = ResourceRecord(
+                        name=rrset.name.to_text(),
+                        rclass=rdataclass.to_text(rr.rdclass),
+                        ttl=rrset.ttl,
+                        rtype=rdatatype.to_text(rr.rdtype),
+                        rdata=rr.to_text()
+                    )
+                    packet.add_answer(resource_record)
+
+            return packet
+        except Exception as e:
+            raise PacketError(f"Failed to parse packet: {str(e)}")
+
+    def __str__(self):
+        header = f"Packet ID: {self.id}, QR: {'Response' if self.qr else 'Query'}, " \
+                 f"Opcode: {self.opcode}, AA: {self.aa}, TC: {self.tc}, RD: {self.rd}, " \
+                 f"RA: {self.ra}, Z: {self.z}, RCODE: {self.rcode}"
+        answers = "\n".join(f"  {rr}" for rr in self.answers)
+        return f"{header}\nAnswers:\n{answers}"

src/public_key.py

@@ -0,0 +1,39 @@
+from .crypto import Crypto
+from .errors import PublicKeyError
+
+class PublicKey:
+    def __init__(self, key):
+        if isinstance(key, str):
+            try:
+                self.key = Crypto.z_base_32_decode(key)
+            except ValueError:
+                raise PublicKeyError("Invalid z-base-32 encoded public key")
+        elif isinstance(key, bytes):
+            if len(key) != 32:
+                raise PublicKeyError("Public key must be 32 bytes long")
+            self.key = key
+        else:
+            raise PublicKeyError("Public key must be bytes or z-base-32 encoded string")
+
+    def __str__(self):
+        return self.to_z32()
+
+    def __repr__(self):
+        return f"PublicKey({self.to_z32()})"
+
+    def __eq__(self, other):
+        if isinstance(other, PublicKey):
+            return self.key == other.key
+        return False
+
+    def __hash__(self):
+        return hash(self.key)
+
+    def to_z32(self):
+        return Crypto.z_base_32_encode(self.key)
+
+    def to_bytes(self):
+        return self.key
+
+    def verify(self, message: bytes, signature: bytes) -> bool:
+        return Crypto.verify(self.key, message, signature)

src/resource_record.py

@@ -0,0 +1,39 @@
+from dataclasses import dataclass
+from typing import Union
+import ipaddress
+
+@dataclass
+class ResourceRecord:
+    name: str
+    rclass: str
+    ttl: int
+    rtype: str
+    rdata: Union[str, ipaddress.IPv4Address, ipaddress.IPv6Address]
+
+    def __post_init__(self):
+        self.name = self.name.lower()
+        self.rclass = self.rclass.upper()
+        self.rtype = self.rtype.upper()
+
+        if self.rtype == 'A':
+            self.rdata = ipaddress.IPv4Address(self.rdata)
+        elif self.rtype == 'AAAA':
+            self.rdata = ipaddress.IPv6Address(self.rdata)
+
+    def to_wire_format(self) -> bytes:
+        # This is a placeholder. You'll need to implement the actual DNS wire format encoding.
+        pass
+
+    @classmethod
+    def from_wire_format(cls, wire_data: bytes) -> 'ResourceRecord':
+        # This is a placeholder. You'll need to implement the actual DNS wire format decoding.
+        pass
+
+    def __str__(self):
+        return f"{self.name} {self.ttl} {self.rclass} {self.rtype} {self.rdata}"
+
+    def is_expired(self, current_time: int) -> bool:
+        return current_time > self.ttl
+
+    def remaining_ttl(self, current_time: int) -> int:
+        return max(0, self.ttl - current_time)

src/signed_packet.py

@@ -0,0 +1,154 @@
+import time
+from dataclasses import dataclass
+from typing import List, Optional
+import ed25519
+from dns import message, name, rdata, rdatatype, rdataclass
+
+@dataclass
+class PublicKey:
+    key: bytes
+
+    def to_z32(self) -> str:
+        # Implement z-base-32 encoding here
+        pass
+
+@dataclass
+class ResourceRecord:
+    name: str
+    rclass: int
+    ttl: int
+    rdata: bytes
+
+@dataclass
+class Packet:
+    answers: List[ResourceRecord]
+
+    @classmethod
+    def new_reply(cls, id: int):
+        return cls(answers=[])
+
+    def build_bytes_vec_compressed(self) -> bytes:
+        # Implement DNS packet compression here
+        pass
+
+@dataclass
+class SignedPacket:
+    public_key: PublicKey
+    signature: bytes
+    timestamp: int
+    packet: Packet
+    last_seen: int
+
+    @classmethod
+    def from_packet(cls, keypair, packet: Packet):
+        timestamp = int(time.time() * 1_000_000)
+        encoded_packet = packet.build_bytes_vec_compressed()
+
+        if len(encoded_packet) > 1000:
+            raise ValueError("Packet too large")
+
+        signature = keypair.sign(cls.signable(timestamp, encoded_packet))
+
+        return cls(
+            public_key=keypair.public_key(),
+            signature=signature,
+            timestamp=timestamp,
+            packet=packet,
+            last_seen=int(time.time() * 1_000_000)
+        )
+
+    @classmethod
+    def from_bytes(cls, data: bytes):
+        if len(data) < 104:
+            raise ValueError("Invalid SignedPacket bytes length")
+        if len(data) > 1104:
+            raise ValueError("Packet too large")
+
+        public_key = PublicKey(data[:32])
+        signature = data[32:96]
+        timestamp = int.from_bytes(data[96:104], 'big')
+        encoded_packet = data[104:]
+
+        # Verify signature
+        if not public_key.verify(cls.signable(timestamp, encoded_packet), signature):
+            raise ValueError("Invalid signature")
+
+        packet = Packet([])  # Parse encoded_packet into a Packet object here
+
+        return cls(
+            public_key=public_key,
+            signature=signature,
+            timestamp=timestamp,
+            packet=packet,
+            last_seen=int(time.time() * 1_000_000)
+        )
+
+    def as_bytes(self) -> bytes:
+        return (
+            self.public_key.key +
+            self.signature +
+            self.timestamp.to_bytes(8, 'big') +
+            self.packet.build_bytes_vec_compressed()
+        )
+
+    def to_relay_payload(self) -> bytes:
+        return self.as_bytes()[32:]
+
+    def resource_records(self, name: str):
+        origin = self.public_key.to_z32()
+        normalized_name = self.normalize_name(origin, name)
+        return [rr for rr in self.packet.answers if rr.name == normalized_name]
+
+    def fresh_resource_records(self, name: str):
+        origin = self.public_key.to_z32()
+        normalized_name = self.normalize_name(origin, name)
+        current_time = int(time.time())
+        return [
+            rr for rr in self.packet.answers
+            if rr.name == normalized_name and rr.ttl > (current_time - self.last_seen // 1_000_000)
+        ]
+
+    def expires_in(self, min_ttl: int, max_ttl: int) -> int:
+        ttl = self.ttl(min_ttl, max_ttl)
+        elapsed = self.elapsed()
+        return max(0, ttl - elapsed)
+
+    def ttl(self, min_ttl: int, max_ttl: int) -> int:
+        if not self.packet.answers:
+            return min_ttl
+        min_record_ttl = min(rr.ttl for rr in self.packet.answers)
+        return max(min_ttl, min(max_ttl, min_record_ttl))
+
+    def elapsed(self) -> int:
+        return (int(time.time() * 1_000_000) - self.last_seen) // 1_000_000
+
+    @staticmethod
+    def signable(timestamp: int, v: bytes) -> bytes:
+        return f"3:seqi{timestamp}e1:v{len(v)}:".encode() + v
+
+    @staticmethod
+    def normalize_name(origin: str, name: str) -> str:
+        if name.endswith('.'):
+            name = name[:-1]
+
+        parts = name.split('.')
+        last = parts[-1]
+
+        if last == origin:
+            return name
+        if last in ('@', ''):
+            return origin
+        return f"{name}.{origin}"
+
+    def __str__(self):
+        records = "\n".join(
+            f"        {rr.name}  IN  {rr.ttl}  {rr.rdata}"
+            for rr in self.packet.answers
+        )
+        return f"""SignedPacket ({self.public_key.key.hex()}):
+    last_seen: {self.elapsed()} seconds ago
+    timestamp: {self.timestamp},
+    signature: {self.signature.hex()}
+    records:
+{records}
+"""