Need fix signatures

protocol_prototype/cli.py

@@ -23,8 +23,8 @@ def main():
     print("  generate_ephemeral_keys")
     print("  send_ping")
     print("  send_handshake")
-    print("  respond_ping <index> <answer_code>")
-    print("  generate_ecdhe <index>   # formerly respond_handshake")
+    print("  respond_ping <index> <0|1>")
+    print("  generate_ecdhe <index>")
     print("  auto_responder <on|off>")
     print("  show_state")
     print("  exit\n")

protocol_prototype/messages.py

@@ -2,7 +2,7 @@ import os
 import struct
 import time
 import zlib
-
+import hashlib
 
 def crc32_of(data: bytes) -> int:
     """
@@ -11,116 +11,222 @@ def crc32_of(data: bytes) -> int:
     return zlib.crc32(data) & 0xffffffff
 
 
-# -----------------------------------------------------------------------------
-# Ping
-# -----------------------------------------------------------------------------
+# =============================================================================
+# 1) Ping Request (295 bits)
+#    - 256-bit nonce
+#    - 7-bit version
+#    - 32-bit CRC
+#    = 295 bits total
+#    In practice, we store 37 bytes (296 bits); 1 bit is unused.
+# =============================================================================
 
-def build_ping_request(version: int = 0) -> bytes:
+def build_ping_request(version: int) -> bytes:
     """
-    Build a Ping request:
-      - Nonce (32 bytes)
-      - Version (1 byte)
-      - CRC-32 (4 bytes)
-    Total = 37 bytes
+    Build a Ping request with:
+      - 256-bit nonce (32 bytes)
+      - 7-bit version
+      - 32-bit CRC
+    We do bit-packing. The final result is 37 bytes (296 bits), with 1 unused bit.
     """
-    nonce = os.urandom(32)
-    partial = nonce + struct.pack("!B", version)
-    crc_val = crc32_of(partial)
-    return partial + struct.pack("!I", crc_val)
+    if not (0 <= version < 128):
+        raise ValueError("Version must fit in 7 bits (0..127)")
+
+    # 1) Generate 256-bit nonce
+    nonce = os.urandom(32)  # 32 bytes = 256 bits
+
+    # We'll build partial_data = [nonce (256 bits), version (7 bits)] as an integer
+    # Then compute CRC-32 over those bytes, then append 32 bits of CRC.
+    partial_int = int.from_bytes(nonce, 'big') << 7  # shift left 7 bits
+    partial_int |= version  # put version in the low 7 bits
+
+    # Convert partial to bytes
+    # partial is 256+7=263 bits => needs 33 bytes to store
+    partial_bytes = partial_int.to_bytes(33, 'big')
+
+    # Compute CRC over partial_bytes
+    cval = crc32_of(partial_bytes)
+
+    # Now combine partial_data (263 bits) with 32 bits of CRC => 295 bits
+    # We'll store that in a single integer
+    final_int = (int.from_bytes(partial_bytes, 'big') << 32) | cval
+    # final_int is 263+32=295 bits, needs 37 bytes to store (the last bit is unused).
+    final_bytes = final_int.to_bytes(37, 'big')
+    return final_bytes
 
 
 def parse_ping_request(data: bytes):
     """
-    Parse a Ping request (37 bytes).
-    Return (nonce, version) or None if invalid.
+    Parse a Ping request (37 bytes = 295 bits).
+    Returns (nonce, version) or None if invalid.
     """
     if len(data) != 37:
         return None
-    nonce = data[:32]
-    version = data[32]
-    crc_in = struct.unpack("!I", data[33:37])[0]
-    partial = data[:33]
-    crc_calc = crc32_of(partial)
+
+    # Convert to int
+    val_295 = int.from_bytes(data, 'big')  # 295 bits in a 37-byte integer
+    # Extract CRC (lowest 32 bits)
+    crc_in = val_295 & 0xffffffff
+    # Then shift right 32 bits to get partial_data
+    partial_val = val_295 >> 32  # 263 bits
+
+    # Convert partial_val back to bytes
+    partial_bytes = partial_val.to_bytes(33, 'big')
+
+    # Recompute CRC
+    crc_calc = crc32_of(partial_bytes)
     if crc_calc != crc_in:
         return None
-    return (nonce, version)
+
+    # Now parse out nonce (256 bits) and version (7 bits)
+    # partial_val is 263 bits
+    version = partial_val & 0x7f  # low 7 bits
+    nonce_val = partial_val >> 7  # high 256 bits
+    nonce_bytes = nonce_val.to_bytes(32, 'big')
+
+    return (nonce_bytes, version)
 
 
-def build_ping_response(version: int, answer_code: int) -> bytes:
+# =============================================================================
+# 2) Ping Response (72 bits)
+#    - 32-bit timestamp
+#    - 7-bit version + 1-bit answer => 8 bits
+#    - 32-bit CRC
+#    = 72 bits total => 9 bytes
+# =============================================================================
+
+def build_ping_response(version: int, answer: int) -> bytes:
     """
     Build a Ping response:
-      - Timestamp (8 bytes)
-      - Version (1 byte)
-      - Answer code (1 byte)
-      - CRC-32 (4 bytes)
-    Total = 14 bytes
+      - 32-bit timestamp (lowest 32 bits of current time in ms)
+      - 7-bit version + 1-bit answer
+      - 32-bit CRC
+    => 72 bits = 9 bytes
     """
-    timestamp = struct.pack("!d", time.time())
-    partial = timestamp + struct.pack("!B", version) + struct.pack("!B", answer_code)
-    crc_val = crc32_of(partial)
-    return partial + struct.pack("!I", crc_val)
+    if not (0 <= version < 128):
+        raise ValueError("Version must fit in 7 bits.")
+    if answer not in (0, 1):
+        raise ValueError("Answer must be 0 or 1.")
+
+    # 32-bit timestamp = current time in ms, truncated to 32 bits
+    t_ms = int(time.time() * 1000) & 0xffffffff
+
+    # partial = [timestamp (32 bits), version (7 bits), answer (1 bit)] => 40 bits
+    partial_val = (t_ms << 8) | ((version << 1) & 0xfe) | (answer & 0x01)
+    # partial_val is 40 bits => 5 bytes
+    partial_bytes = partial_val.to_bytes(5, 'big')
+
+    # CRC over these 5 bytes
+    cval = crc32_of(partial_bytes)
+
+    # Combine partial (40 bits) with 32 bits of CRC => 72 bits total
+    final_val = (int.from_bytes(partial_bytes, 'big') << 32) | cval
+    final_bytes = final_val.to_bytes(9, 'big')
+    return final_bytes
 
 
 def parse_ping_response(data: bytes):
     """
-    Parse a Ping response (14 bytes).
-    Return (timestamp, version, answer_code) or None if invalid.
+    Parse a Ping response (72 bits = 9 bytes).
+    Return (timestamp_ms, version, answer) or None if invalid.
     """
-    if len(data) != 14:
+    if len(data) != 9:
         return None
-    timestamp = struct.unpack("!d", data[:8])[0]
-    version = data[8]
-    answer_code = data[9]
-    crc_in = struct.unpack("!I", data[10:14])[0]
-    partial = data[:10]
-    crc_calc = crc32_of(partial)
+
+    val_72 = int.from_bytes(data, 'big')  # 72 bits
+    crc_in = val_72 & 0xffffffff
+    partial_val = val_72 >> 32  # 40 bits
+
+    partial_bytes = partial_val.to_bytes(5, 'big')
+    crc_calc = crc32_of(partial_bytes)
     if crc_calc != crc_in:
         return None
-    return (timestamp, version, answer_code)
+
+    # Now parse partial_val
+    # partial_val = [timestamp(32 bits), version(7 bits), answer(1 bit)]
+    t_ms = (partial_val >> 8) & 0xffffffff
+    va = partial_val & 0xff  # 8 bits = [7 bits version, 1 bit answer]
+    version = (va >> 1) & 0x7f
+    answer = va & 0x01
+
+    return (t_ms, version, answer)
 
 
-# -----------------------------------------------------------------------------
-# Handshake
-# -----------------------------------------------------------------------------
+# =============================================================================
+# 3) Handshake
+#    - 32-bit timestamp
+#    - 64-byte ephemeral pubkey (raw x||y = 512 bits)
+#    - 64-byte ephemeral signature (raw r||s = 512 bits)
+#    - 32-byte PFS hash (256 bits)
+#    - 32-bit CRC
+#    => total 4 + 64 + 64 + 32 + 4 = 168 bytes = 1344 bits
+# =============================================================================
 
-def build_handshake_message(ephemeral_pubkey: bytes, ephemeral_signature: bytes, timestamp: float) -> bytes:
+def build_handshake_message(timestamp: int,
+                            ephemeral_pubkey: bytes,
+                            ephemeral_signature: bytes,
+                            pfs_hash: bytes) -> bytes:
     """
-    Build a handshake message:
-      - ephemeral_pubkey (64 bytes)
-      - ephemeral_signature (72 bytes, DER + zero-pad)
-      - timestamp (8 bytes)
-      - CRC-32 (4 bytes)
-    Total = 148 bytes
+    Build handshake:
+      - 4 bytes: timestamp
+      - 64 bytes: ephemeral_pubkey (x||y, raw)
+      - 64 bytes: ephemeral_signature (r||s, raw)
+      - 32 bytes: pfs_hash
+      - 4 bytes: CRC-32
+    => 168 bytes total
     """
     if len(ephemeral_pubkey) != 64:
-        raise ValueError("ephemeral_pubkey must be 64 bytes")
-    if len(ephemeral_signature) > 72:
-        raise ValueError("ephemeral_signature too large")
+        raise ValueError("ephemeral_pubkey must be 64 bytes (raw x||y).")
+    if len(ephemeral_signature) != 64:
+        raise ValueError("ephemeral_signature must be 64 bytes (raw r||s).")
+    if len(pfs_hash) != 32:
+        raise ValueError("pfs_hash must be 32 bytes.")
 
-    sig_padded = ephemeral_signature.ljust(72, b'\x00')
-    ts_bytes = struct.pack("!d", timestamp)
-    partial = ephemeral_pubkey + sig_padded + ts_bytes
-    crc_val = crc32_of(partial)
-    return partial + struct.pack("!I", crc_val)
+    partial = struct.pack("!I", timestamp) \
+              + ephemeral_pubkey \
+              + ephemeral_signature \
+              + pfs_hash
+    cval = crc32_of(partial)
+    return partial + struct.pack("!I", cval)
 
 
 def parse_handshake_message(data: bytes):
     """
-    Parse a handshake message (148 bytes).
-    Return (ephemeral_pubkey, ephemeral_signature, timestamp) or None if invalid.
+    Parse handshake message (168 bytes).
+    Return (timestamp, ephemeral_pub, ephemeral_sig, pfs_hash) or None if invalid.
     """
-    if len(data) != 148:
+    if len(data) != 168:
         return None
-    ephemeral_pubkey = data[:64]
-    sig_padded = data[64:136]
-    ts_bytes = data[136:144]
-    crc_in = struct.unpack("!I", data[144:148])[0]
-
-    partial = data[:144]
+    partial = data[:-4]   # first 164 bytes
+    crc_in = struct.unpack("!I", data[-4:])[0]
     crc_calc = crc32_of(partial)
     if crc_calc != crc_in:
         return None
 
-    ephemeral_signature = sig_padded.rstrip(b'\x00')
-    timestamp = struct.unpack("!d", ts_bytes)[0]
-    return (ephemeral_pubkey, ephemeral_signature, timestamp)
+    # Now parse fields
+    timestamp = struct.unpack("!I", partial[:4])[0]
+    ephemeral_pub = partial[4:4+64]
+    ephemeral_sig = partial[68:68+64]
+    pfs_hash = partial[132:132+32]
+    return (timestamp, ephemeral_pub, ephemeral_sig, pfs_hash)
+
+
+# =============================================================================
+# 4) PFS Hash Helper
+#    If no previous session, return 32 zero bytes
+#    Otherwise, compute sha256(session_number || last_shared_secret).
+# =============================================================================
+
+def compute_pfs_hash(session_number: int, shared_secret_hex: str) -> bytes:
+    """
+    Return 32 bytes (256 bits) for the PFS field.
+    If session_number < 0 => means no previous session => 32 zero bytes.
+    Otherwise => sha256( session_number (4 bytes) || shared_secret ).
+    """
+    if session_number < 0:
+        return b"\x00" * 32
+
+    # Convert shared_secret_hex to raw bytes
+    secret_bytes = bytes.fromhex(shared_secret_hex)
+    # Pack session_number as 4 bytes
+    sn_bytes = struct.pack("!I", session_number)
+    return hashlib.sha256(sn_bytes + secret_bytes).digest()

protocol_prototype/protocol.py

@@ -14,11 +14,12 @@ from crypto_utils import (
 from messages import (
     build_ping_request, parse_ping_request,
     build_ping_response, parse_ping_response,
-    build_handshake_message, parse_handshake_message
+    build_handshake_message, parse_handshake_message,
+    compute_pfs_hash
 )
 import transmission
 
-# ANSI colors for pretty printing
+# ANSI colors
 RED = "\033[91m"
 GREEN = "\033[92m"
 YELLOW = "\033[93m"
@@ -31,22 +32,21 @@ class IcingProtocol:
         # Identity keys
         self.identity_privkey, self.identity_pubkey = generate_identity_keys()
 
-        # Peer identity (public key) for verifying ephemeral signatures
+        # Peer identity
         self.peer_identity_pubkey_obj = None
         self.peer_identity_pubkey_bytes = None
 
-        # Ephemeral keys (our side)
+        # Ephemeral keys
         self.ephemeral_privkey = None
         self.ephemeral_pubkey = None
 
-        # Store the last computed shared secret (hex) from ECDH
+        # Last computed shared secret (hex)
         self.shared_secret = None
 
-        # Track open connections
-        self.connections = []
-
-        # A random listening port
-        self.local_port = random.randint(30000, 40000)
+        # For PFS: track session_number + last_shared_secret per peer identity
+        # Key: bytes(64) peer identity pubkey
+        # Value: (int session_number, str last_shared_secret_hex)
+        self.pfs_history: Dict[bytes, (int, str)] = {}
 
         # Inbound messages are stored for manual or auto handling
         # Each entry: { 'type': str, 'raw': bytes, 'parsed': Any, 'connection': PeerConnection }
@@ -63,7 +63,11 @@ class IcingProtocol:
         # Auto-responder toggle
         self.auto_responder = False
 
-        # Start the listener
+        # Connections
+        self.connections = []
+
+        # Listening port
+        self.local_port = random.randint(30000, 40000)
         self.server_listener = transmission.ServerListener(
             host="127.0.0.1",
             port=self.local_port,
@@ -86,7 +90,7 @@ class IcingProtocol:
         We'll parse and store the message, then handle automatically if auto_responder is on.
         """
         # Print data size in bits, not bytes
-        bits_count = len(data) * 8
+        bits_count = len(data)*8
         print(f"{GREEN}[RECV]{RESET} {bits_count} bits from peer: {data.hex()[:60]}{'...' if len(data.hex())>60 else ''}")
 
         # Attempt to parse Ping request
@@ -112,7 +116,7 @@ class IcingProtocol:
                 return
 
         # Attempt to parse Ping response
-        if len(data) == 14:
+        if len(data) == 9:
             parsed = parse_ping_response(data)
             if parsed:
                 ts, version, answer_code = parsed
@@ -128,10 +132,10 @@ class IcingProtocol:
                 return
 
         # Attempt to parse handshake
-        if len(data) == 148:
+        if len(data) == 168:
             parsed = parse_handshake_message(data)
             if parsed:
-                ephemeral_pub, ephemeral_sig, ts = parsed
+                ts, ephemeral_pub, ephemeral_sig, pfs_hash = parsed
                 self.state["handshake_received"] = True
                 index = len(self.inbound_messages)
                 msg = {
@@ -140,7 +144,8 @@ class IcingProtocol:
                     "parsed": {
                         "ephemeral_pub": ephemeral_pub,
                         "ephemeral_sig": ephemeral_sig,
-                        "timestamp": ts
+                        "timestamp": ts,
+                        "pfs hash": pfs_hash
                     },
                     "connection": conn
                 }
@@ -228,18 +233,48 @@ class IcingProtocol:
 
     def send_handshake(self):
         """
-        Build and send a handshake message with ephemeral keys.
+        Build and send handshake:
+          - 32-bit timestamp
+          - ephemeral_pubkey (64 bytes, raw x||y)
+          - ephemeral_signature (64 bytes, raw r||s)
+          - pfs_hash (32 bytes)
+          - 32-bit CRC
         """
         if not self.connections:
             print(f"{RED}[ERROR]{RESET} No active connections.")
             return
         if not self.ephemeral_privkey or not self.ephemeral_pubkey:
-            print(f"{RED}[ERROR]{RESET} Ephemeral keys not generated. Call 'generate_ephemeral_keys' first.")
+            print(f"{RED}[ERROR]{RESET} Ephemeral keys not generated.")
+            return
+        if self.peer_identity_pubkey_bytes is None:
+            print(f"{RED}[ERROR]{RESET} Peer identity not set; needed for PFS tracking.")
             return
 
-        ephemeral_signature = sign_data(self.identity_privkey, self.ephemeral_pubkey)
-        ts_now = time.time()
-        pkt = build_handshake_message(self.ephemeral_pubkey, ephemeral_signature, ts_now)
+        # 1) Sign ephemeral_pubkey as r||s
+        #    Instead of DER, we do raw r||s each 32 bytes
+        sig_der = sign_data(self.identity_privkey, self.ephemeral_pubkey)
+        # Convert DER -> (r, s) -> raw 64 bytes
+        # Quick approach to parse DER using cryptography, or do a custom parse
+        from cryptography.hazmat.primitives.asymmetric.utils import decode_dss_signature
+        r_int, s_int = decode_dss_signature(sig_der)
+        r_bytes = r_int.to_bytes(32, 'big')
+        s_bytes = s_int.to_bytes(32, 'big')
+        raw_signature = r_bytes + s_bytes  # 64 bytes
+
+        # 2) PFS hash
+        session_number, last_secret_hex = self.pfs_history.get(self.peer_identity_pubkey_bytes, (-1, ""))
+        pfs = compute_pfs_hash(session_number, last_secret_hex)
+
+        # 3) Build handshake
+        timestamp_32 = int(time.time() * 1000) & 0xffffffff
+        pkt = build_handshake_message(
+            timestamp_32,
+            self.ephemeral_pubkey,  # 64 bytes raw
+            raw_signature,  # 64 bytes raw
+            pfs  # 32 bytes
+        )
+
+        # 4) Send
         self._send_packet(self.connections[0], pkt, "HANDSHAKE")
         self.state["handshake_sent"] = True
 
@@ -316,17 +351,18 @@ class IcingProtocol:
     def show_state(self):
         print(f"\n{YELLOW}=== Global State ==={RESET}")
         print(f"Listening Port: {self.local_port}")
-        print(f"Identity PubKey: {self.identity_pubkey.hex()[:16]}... (64 bytes)")
+        print(f"Identity PubKey: 512 bits => {self.identity_pubkey.hex()[:16]}...")
+
         if self.peer_identity_pubkey_bytes:
-            print(f"Peer Identity PubKey: {self.peer_identity_pubkey_bytes.hex()[:16]}... (64 bytes)")
+            print(f"Peer Identity PubKey: 512 bits => {self.peer_identity_pubkey_bytes.hex()[:16]}...")
         else:
             print("Peer Identity PubKey: [None]")
 
         print("\nEphemeral Keys:")
         if self.ephemeral_pubkey:
-            print(f"  ephemeral_pubkey={self.ephemeral_pubkey.hex()[:16]}...")
+            print(f"  ephemeral_pubkey: 512 bits => {self.ephemeral_pubkey.hex()[:16]}...")
         else:
-            print("  ephemeral_pubkey=[None]")
+            print("  ephemeral_pubkey: [None]")
 
         print(f"\nShared Secret: {self.shared_secret if self.shared_secret else '[None]'}")
 
@@ -342,7 +378,7 @@ class IcingProtocol:
 
         print("\nInbound Message Queue:")
         for i, m in enumerate(self.inbound_messages):
-            print(f"  [{i}] type={m['type']} len={len(m['raw'])} bytes")
+            print(f"  [{i}] type={m['type']} len={len(m['raw'])} bytes => {len(m['raw']) * 8} bits")
         print()
 
     def stop(self):