feat(linux_client): add mTLS connection and automatic enrollment in src/Linux_Client.py

src/Linux_Client.py

@@ -2,9 +2,11 @@ import os
 import sys
 import json
 import socket
+import ssl
 import struct
 import argparse
 import subprocess
+import urllib.request
 import warnings
 from datetime import datetime, timezone, timedelta
 from typing import Optional, Dict, Any, List
@@ -18,6 +20,68 @@ CONFIG_FILE_NAME = "client_config.json"
 STATE_FILE_NAME = "client_state.json"
 
 
+def enroll_client_if_needed(hub_url: str, enrollment_secret: str, cert_dir: str, client_id: str, hostname: str, os_type: str = "linux"):
+    """Bootstraps client enrollment if certificates are missing."""
+    os.makedirs(cert_dir, exist_ok=True)
+    ca_path = os.path.join(cert_dir, "ca.crt")
+    cert_path = os.path.join(cert_dir, "client.crt")
+    key_path = os.path.join(cert_dir, "client.key")
+
+    if os.path.exists(ca_path) and os.path.exists(cert_path) and os.path.exists(key_path):
+        return True
+
+    print(f"[*] Bootstrapping client enrollment with LOGAR Hub at {hub_url}...")
+    enroll_endpoint = f"{hub_url.rstrip('/')}/api/client/enroll"
+    payload = {
+        "client_id": client_id,
+        "hostname": hostname,
+        "os": os_type,
+        "enrollment_secret": enrollment_secret
+    }
+    req = urllib.request.Request(
+        enroll_endpoint,
+        data=json.dumps(payload).encode("utf-8"),
+        headers={"Content-Type": "application/json"}
+    )
+    with urllib.request.urlopen(req, timeout=10) as resp:
+        if resp.status != 200:
+            raise RuntimeError(f"Enrollment failed with status code {resp.status}")
+        data = json.loads(resp.read().decode("utf-8"))
+
+    with open(ca_path, "w", encoding="utf-8") as f:
+        f.write(data["ca_cert"])
+    with open(cert_path, "w", encoding="utf-8") as f:
+        f.write(data["client_cert"])
+    with open(key_path, "w", encoding="utf-8") as f:
+        f.write(data["client_key"])
+
+    try:
+        os.chmod(key_path, 0o600)
+    except Exception:
+        pass
+
+    print(f"[+] Client enrolled successfully! Certificates saved to {os.path.abspath(cert_dir)}")
+    return True
+
+
+def get_tls_socket(hub_host: str, hub_port: int, cert_dir: str):
+    """Establishes an mTLS connection with the LOGAR hub using client certificates."""
+    ca_path = os.path.join(cert_dir, "ca.crt")
+    cert_path = os.path.join(cert_dir, "client.crt")
+    key_path = os.path.join(cert_dir, "client.key")
+
+    if not (os.path.exists(ca_path) and os.path.exists(cert_path) and os.path.exists(key_path)):
+        raise FileNotFoundError(f"mTLS certificates not found in '{cert_dir}'. Enroll client first.")
+
+    ctx = ssl.create_default_context(ssl.Purpose.SERVER_AUTH, cafile=ca_path)
+    ctx.load_cert_chain(certfile=cert_path, keyfile=key_path)
+    ctx.minimum_version = ssl.TLSVersion.TLSv1_3
+    ctx.check_hostname = False
+
+    raw_sock = socket.create_connection((hub_host, hub_port), timeout=15)
+    return ctx.wrap_socket(raw_sock, server_hostname=hub_host)
+
+
 def get_state_path(config_path: str, custom_state_path: Optional[str] = None) -> str:
     if custom_state_path:
         return custom_state_path
@@ -227,39 +291,80 @@ def get_recent_linux_logs(hours: int = 24, state: Optional[dict] = None) -> list
 
 def send_encrypted_logs_over_socket(config: dict, logs: list):
     """
-    Encrypts the payload using the server's OpenPGP public key and streams
+    Streams logs to the LOGAR hub.
-    over an authenticated TCP socket.
+    Uses mutual TLS 1.3 (mTLS) with client certificates if available,
+    or falls back to OpenPGP encrypted envelope over TCP.
     """
     server_host = config["server_host"]
     server_port = int(config["server_port"])
-    auth_token = config["auth_token"]
+    cert_dir = config.get("cert_dir", "certs")
-    pub_key_armored = config["server_public_key"]
+    enrollment_secret = config.get("enrollment_secret")
-    expected_fp = config.get("server_fingerprint", "").replace(" ", "").upper()
+    machine_id = get_machine_identifier()
 
-    # Load and verify server public key
+    # Attempt automatic enrollment bootstrap if certs are missing and secret is provided
+    if enrollment_secret:
+        hermes_host = config.get("hermes_host", server_host)
+        hermes_port = config.get("hermes_port", 8443)
+        hub_url = f"http://{hermes_host}:{hermes_port}"
+        try:
+            enroll_client_if_needed(hub_url, enrollment_secret, cert_dir, machine_id, machine_id, os_type="linux")
+        except Exception as e:
+            print(f"[!] Warning: Enrollment bootstrap failed: {e}")
+
+    ca_path = os.path.join(cert_dir, "ca.crt")
+    cert_path = os.path.join(cert_dir, "client.crt")
+    key_path = os.path.join(cert_dir, "client.key")
+    has_mtls_certs = os.path.exists(ca_path) and os.path.exists(cert_path) and os.path.exists(key_path)
+
+    if has_mtls_certs:
+        print(f"[*] Connecting to LOGAR server at {server_host}:{server_port} over mTLS (TLS 1.3)...")
+        with get_tls_socket(server_host, server_port, cert_dir) as sock:
+            payload = {
+                "server": machine_id,
+                "timestamp": datetime.now(timezone.utc).isoformat(),
+                "logs": logs
+            }
+            payload_bytes = json.dumps(payload).encode("utf-8")
+            frame = struct.pack(">I", len(payload_bytes)) + payload_bytes
+            sock.sendall(frame)
+
+            resp_len_bytes = sock.recv(4)
+            if not resp_len_bytes:
+                raise ConnectionError("Server closed mTLS connection without response.")
+            resp_len = struct.unpack(">I", resp_len_bytes)[0]
+            resp_bytes = bytearray()
+            while len(resp_bytes) < resp_len:
+                chunk = sock.recv(min(4096, resp_len - len(resp_bytes)))
+                if not chunk:
+                    break
+                resp_bytes.extend(chunk)
+
+            response = json.loads(resp_bytes.decode("utf-8"))
+            print(f"[+] Server response: {response}")
+            return response
+
+    # Fallback to OpenPGP envelope over plain TCP socket
+    auth_token = config.get("auth_token", "")
+    pub_key_armored = config.get("server_public_key")
+    if not pub_key_armored:
+        raise ValueError("No server public key or mTLS certificates available for connection.")
+
+    expected_fp = config.get("server_fingerprint", "").replace(" ", "").upper()
     pub_key, _ = pgpy.PGPKey.from_blob(pub_key_armored)
     actual_fp = str(pub_key.fingerprint).replace(" ", "").upper()
     if expected_fp and actual_fp != expected_fp:
-        raise ValueError(
+        raise ValueError(f"Server fingerprint mismatch! Expected {expected_fp}, but key has {actual_fp}.")
-            f"Server fingerprint mismatch! Expected {expected_fp}, but key has {actual_fp}."
-        )
 
-    machine_id = get_machine_identifier()
-
-    # Prepare batch
     payload = {
         "server": machine_id,
         "timestamp": datetime.now(timezone.utc).isoformat(),
         "logs": logs
     }
     payload_json = json.dumps(payload)
-
-    # Encrypt payload with server's encryption-only key
     pgp_msg = pgpy.PGPMessage.new(payload_json)
     encrypted_msg = pub_key.encrypt(pgp_msg)
     encrypted_armored = str(encrypted_msg)
 
-    # Envelope with socket authentication header
     envelope = {
         "auth_token": auth_token,
         "timestamp": datetime.now(timezone.utc).isoformat(),
@@ -267,17 +372,14 @@ def send_encrypted_logs_over_socket(config: dict, logs: list):
     }
     envelope_bytes = json.dumps(envelope).encode("utf-8")
 
-    # Connect over TCP socket and transmit with 4-byte length prefix framing
     print(f"[*] Connecting to LOGAR server at {server_host}:{server_port} over secure TCP socket...")
     with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
         sock.settimeout(15.0)
         sock.connect((server_host, server_port))
 
-        # Send frame: length (4 bytes big-endian) + envelope
         frame = struct.pack(">I", len(envelope_bytes)) + envelope_bytes
         sock.sendall(frame)
 
-        # Receive response length
         resp_len_bytes = sock.recv(4)
         if not resp_len_bytes:
             raise ConnectionError("Server closed connection without response.")