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fix: session nonce to prevent stale session reuse, reorganize hivemind, clean AdMob bypass toggle

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esefxdz committed 2026-07-18 13:02:04 +03:00
1 parent 08f08fbf3e
commit 0943506404
4 files changed
+405 -334
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.gitignore
+1
View File
@@ -65,6 +65,7 @@ local_packages/*/.dart_tool/
# Secrets
android/key.properties
android/admob.properties
AGENTS.md
SERVER_NOTES.md
lib/logic/backup/
00-FULL-REPORT.md
lib/logic/ad_manager.dart
+9 -1
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@@ -1,5 +1,6 @@
import 'dart:async';
import 'dart:convert';
import 'dart:math';
import 'package:flutter/foundation.dart';
import 'package:google_mobile_ads/google_mobile_ads.dart';
import 'package:paladinvpn/logic/crypto_service.dart';
@@ -102,12 +103,19 @@ class AdManager extends ChangeNotifier {
final keys = await CryptoService.getOrCreateKeys();
final pubKey = keys['publicKey']!;
// 3. Build SSV options to send to our Hivemind server via Google's callback
// 3. Generate a connect nonce so the subsequent poll can verify
// it's talking to the session created by *this* ad.
final nonce = '${Random().nextInt(0x7FFFFFFF)}-${DateTime.now().millisecondsSinceEpoch}';
HivemindService.setExpectedNonce(nonce);
debugPrint('[AdManager] Ad nonce: $nonce');
// 4. Build SSV options to send to our Hivemind server via Google's callback
final ssvOptions = ServerSideVerificationOptions(
customData: jsonEncode({
'device_id': deviceId,
'public_key': pubKey,
'ad_type': adType,
'nonce': nonce,
}),
);
lib/logic/hivemind_service.dart
+37 -3
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@@ -1,22 +1,46 @@
import 'dart:async';
import 'dart:convert';
import 'dart:math';
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
import 'package:paladinvpn/logic/app_config.dart';
import 'package:paladinvpn/logic/crypto_service.dart';
class HivemindService {
/// Nonce generated at the start of a connect cycle.
/// Sent to the server during session creation and verified in every poll
/// response so we never accidentally resume a stale session.
static String? _expectedNonce;
/// Stores a nonce so that fetchConfigWithPolling can verify it.
/// Called by AdManager.showAd() before showing a rewarded ad so the
/// subsequent poll accepts only the session created by *this* ad.
static void setExpectedNonce(String nonce) {
_expectedNonce = nonce;
}
/// Polls the Hivemind server until the session is ready or timeout occurs.
/// Returns the WireGuard config string.
///
/// [onAttempt] is called after each poll with (current, total) so the UI
/// can show progress (e.g. "Contacting server (3/15)…").
static Future<String> fetchConfigWithPolling({
void Function(int attempt, int total)? onAttempt,
}) async {
final deviceId = await CryptoService.getDeviceId();
final keys = await CryptoService.getOrCreateKeys();
final privKey = keys['privateKey']!;
// ── Generate a connect nonce ──────────────────────────────────────
// Every fresh connect cycle gets a new random token. The server
// stores it in the session and echoes it back in /session/status.
// If the poll returns a session whose nonce differs (e.g. a stale
// leftover from a failed disconnectAndCleanup), we skip it and keep
// polling until the right session appears or the timeout fires.
final nonce = '${Random().nextInt(0x7FFFFFFF)}-${DateTime.now().millisecondsSinceEpoch}';
_expectedNonce = nonce;
debugPrint('[HivemindService] Connect nonce: $nonce');
final url = Uri.parse('${AppConfig.hivemindApiBase}/session/status?device_id=$deviceId');
@@ -30,6 +54,7 @@ class HivemindService {
'device_id': deviceId,
'public_key': keys['publicKey']!,
'ad_type': 'main_ad',
'nonce': nonce,
});
final fakeAdmobPingUrl = Uri.parse(
'${AppConfig.hivemindApiBase}/admob/callback?signature=test&key_id=test&custom_data=${Uri.encodeComponent(customData)}');
@@ -47,9 +72,17 @@ class HivemindService {
if (response.statusCode == 200) {
final data = jsonDecode(response.body);
debugPrint('[HivemindService] Session active, constructing config…');
if (data['active'] == true && data['client_ip'] != null && data['server_pubkey'] != null) {
debugPrint('[HivemindService] Session found, checking nonce…');
// ── Nonce gate ──────────────────────────────────────────────
// Reject any session whose nonce doesn't match what we sent.
// If the server is old and doesn't return a nonce we still
// accept it (backwards-compat), but a mismatch is a hard skip.
final serverNonce = data['nonce'] as String?;
if (_expectedNonce != null && serverNonce != null && serverNonce != _expectedNonce) {
debugPrint('[HivemindService] Nonce mismatch (expected $_expectedNonce, got $serverNonce) — stale session, retrying…');
// Fall through to retry — do NOT accept this session.
} else if (data['active'] == true && data['client_ip'] != null && data['server_pubkey'] != null) {
final clientIp = data['client_ip'];
final clientIpv6 = data['client_ipv6'] ?? '';
final serverPubkey = data['server_pubkey'];
@@ -82,6 +115,7 @@ AllowedIPs = ${AppConfig.allowedIps}
Endpoint = ${AppConfig.serverEndpoint}
PersistentKeepalive = ${AppConfig.persistentKeepalive}
''';
_expectedNonce = null; // consumed successfully
return configText;
}
} else {
server_hivemind_5_0.py
+358 -330
View File
@@ -3,6 +3,18 @@
Hivemind VPN Session Manager
Manages time + data quotas for AmneziaWG peers via ad rewards.
Designed for Android-only clients.
=== TABLE OF CONTENTS ===========================================================
LINE SECTION
44 Configuration — ad rewards, throttle rate, check interval
60 State & Cache — sessions dict, IP pool, server pubkey
93 Flask Routes — /admob/callback, /session/status, /session/stop
220 Session Logic — _start_or_extend_session (create / extend)
295 AdMob SSV Verification — Google ECDSA signature checks
380 Management Loop — expiry + data-quota watchdog (60 s tick)
426 Low-Level Plumbing — awg commands, tc throttling, IP pool, peers
567 Entry Point — daemon thread + gunicorn bootstrap
================================================================================
"""
import time
@@ -13,11 +25,12 @@ import requests
import shlex
import re
import urllib.parse
import ipaddress
import base64
from flask import Flask, request, jsonify
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.serialization import load_der_public_key, load_pem_public_key
import base64
app = Flask(__name__)
@@ -44,6 +57,15 @@ BONUS_AD_BYTES = 1 * 1024 * 1024 * 1024 # 1 GB
THROTTLE_RATE = "1.5mbit"
# AdMob SSV verification toggle
# True = dev mode, accept any callback (no signature check)
# False = prod mode, enforce Google ECDSA signature verification
#
# ⚠️ Set to False AFTER Google Play verifies your AdMob implementation is
# working correctly with real rewarded ads. Until then, keep True so
# the debug fake-callback path in the Flutter app still functions.
ADMOB_BYPASS = True
# ==============================================================================
# STATE & CACHE
# ==============================================================================
@@ -61,7 +83,8 @@ SERVER_PUBKEY = None
# "expires_at": 1716480000,
# "quota_bytes": 2147483648,
# "baseline_bytes": 0,
# "is_throttled": False
# "is_throttled": False,
# "nonce": "a7f3b2-1716480000000",
# }
# }
active_sessions = {}
@@ -70,10 +93,342 @@ active_sessions = {}
IP_POOL_START = 100
IP_POOL_END = 250
# Pre-computed pool of all available IPv4 addresses in the 10.8.0.0/16 subnet.
# Initialised once at module load; allocate_ip() pops from it, release_ip() returns to it.
AVAILABLE_IPS = {str(ip) for ip in ipaddress.IPv4Network('10.8.0.0/16').hosts()}
AVAILABLE_IPS.discard('10.8.0.1')
# ==============================================================================
# SYSTEM COMMAND HELPERS
# FLASK ROUTES (API surface — what the outside world sees)
# ==============================================================================
@app.route('/api/admob/callback', methods=['GET'])
def admob_callback():
"""
Google AdMob SSV callback — called server-to-server when a rewarded ad completes.
The Android client never touches this endpoint; Google calls it directly.
custom_data (JSON, set by the app before showing the ad):
{ "device_id": "...", "public_key": "...", "ad_type": "main_ad"|"bonus_ad", "nonce": "..." }
"""
try:
if ADMOB_BYPASS:
# ── DEV: accept any callback without signature verification ──
custom_data_str = request.args.get('custom_data')
if not custom_data_str:
return "OK", 200
else:
# ── PROD: enforce Google ECDSA signature verification ────────
signature = request.args.get('signature')
key_id = request.args.get('key_id')
custom_data_str = request.args.get('custom_data')
# Google sends a verification ping with signature+key_id but no custom_data
if not custom_data_str:
return "OK", 200
if not all([signature, key_id]):
return "Missing parameters", 400
raw_qs = request.query_string.decode("utf-8")
if not _verify_admob_signature(raw_qs, signature, key_id):
print("[ADMOB] Rejected callback — invalid signature.")
return "Forbidden", 403
custom_data = json.loads(custom_data_str)
device_id = custom_data.get('device_id')
client_pubkey = custom_data.get('public_key')
if not device_id or not client_pubkey:
return "Invalid custom_data payload", 400
ad_type = custom_data.get('ad_type', 'main_ad')
nonce = custom_data.get('nonce', None)
success, msg = _start_or_extend_session(device_id, client_pubkey, ad_type, nonce)
return ("OK", 200) if success else (msg, 500)
except Exception as e:
print(f"[ADMOB] SSV Error: {e}")
return "Internal Error", 500
@app.route('/api/session/status', methods=['GET'])
def session_status():
"""
Query: ?device_id=esf-xxx
Returns current session state so the Android app can construct its AmneziaWG config.
"""
device_id = request.args.get('device_id')
if not device_id:
return jsonify({"error": "Missing query parameter: device_id"}), 400
with sessions_lock:
session = active_sessions.get(device_id)
if not session:
return jsonify({"active": False, "message": "No session found."}), 404
# Bulletproof fallback: If server public key is missing, try fetching it right now
global SERVER_PUBKEY
if not SERVER_PUBKEY:
pubkey = run_cmd("awg show awg0 public-key")
if pubkey:
SERVER_PUBKEY = pubkey
print(f"[AWG] Dynamic Server Public Key cached from awg0: {SERVER_PUBKEY}")
else:
SERVER_PUBKEY = SERVER_PUBKEY_FALLBACK or "server key="
stats = get_wireguard_stats()
current_bytes = stats.get(session["ip"], {}).get("total_bytes", 0)
used_bytes = max(0, current_bytes - session["baseline_bytes"])
remaining_data = max(0, session["quota_bytes"] - used_bytes)
remaining_secs = max(0, session["expires_at"] - time.time())
return jsonify({
"active": remaining_secs > 0,
"client_ip": session["ip"],
"client_ipv6": session.get("ipv6", ""),
"server_pubkey": SERVER_PUBKEY,
"is_throttled": session["is_throttled"],
"expires_in_seconds": int(remaining_secs),
"quota_bytes": session["quota_bytes"],
"used_bytes": used_bytes,
"remaining_bytes": remaining_data,
"nonce": session.get("nonce", ""),
})
@app.route('/api/session/stop', methods=['POST'])
def session_stop():
"""Allows the app to explicitly tear down its session on disconnect."""
data = request.get_json(silent=True)
device_id = data.get('device_id') if data else None
if device_id:
with sessions_lock:
session = active_sessions.pop(device_id, None)
if session:
remove_wg_peer(session["pubkey"])
if session["is_throttled"]:
remove_throttle(session["ip"])
release_ip(session["ip"])
print(f"[API] Explicit stop for {device_id}.")
return jsonify({"success": True})
# ==============================================================================
# SESSION LOGIC
# ==============================================================================
def _start_or_extend_session(device_id, client_pubkey, ad_type, nonce=None):
"""Core logic to provision or extend a session.
nonce -- client-generated random token; stored in session and echoed
back in /session/status so the client can reject stale sessions.
"""
if not re.match(r"^[A-Za-z0-9+/=]{43,44}$", client_pubkey):
return False, "Invalid WireGuard public key format"
now = time.time()
with sessions_lock:
if device_id in active_sessions and ad_type == 'bonus_ad':
# Extend existing session
session = active_sessions[device_id]
session["expires_at"] += (BONUS_AD_MINUTES * 60)
session["quota_bytes"] += BONUS_AD_BYTES
if session["is_throttled"]:
remove_throttle(session["ip"])
session["is_throttled"] = False
stats = get_wireguard_stats()
current_bytes = stats.get(session["ip"], {}).get("total_bytes", 0)
session["baseline_bytes"] = current_bytes
print(f"[SESSION] Bonus time added for {device_id} (IP: {session['ip']}).")
return True, "Bonus time and data added."
else:
# Create a brand new session (Main Ad)
if not validate_wg_pubkey(client_pubkey):
print(f"[SESSION] Rejected invalid pubkey from {device_id[:8]}...")
return False, "Invalid public key format."
existing = active_sessions.get(device_id)
if existing:
if existing["is_throttled"]:
remove_throttle(existing["ip"])
remove_wg_peer(existing["pubkey"])
release_ip(existing["ip"])
ipv4 = allocate_ip()
if not ipv4:
return False, "Server full! No available IP addresses."
ipv6 = ipv4_to_ipv6(ipv4)
add_wg_peer(client_pubkey, ipv4, ipv6)
# Fetch immediate stats to set baseline
# (Though brand new peers usually start at 0)
stats = get_wireguard_stats()
current_bytes = stats.get(ipv4, {}).get("total_bytes", 0)
active_sessions[device_id] = {
"ip": ipv4,
"ipv6": ipv6,
"pubkey": client_pubkey,
"expires_at": now + (MAIN_AD_MINUTES * 60),
"quota_bytes": MAIN_AD_BYTES,
"baseline_bytes": current_bytes,
"is_throttled": False,
"nonce": nonce,
}
print(f"[SESSION] Main session started for {device_id} (IP: {ipv4} / {ipv6}).")
return True, "Main session active."
# ==============================================================================
# ADMOB SERVER-TO-SERVER (SSV) VERIFICATION
# ==============================================================================
ADMOB_KEYS_URL = "https://www.gstatic.com/admob/reward/verifier-keys.json"
# Cache: { key_id_str: EllipticCurvePublicKey }
# Refreshed at most once every 24 hours so we don't hammer Google's CDN.
_admob_key_cache = {}
_admob_keys_fetched_at = 0.0
_ADMOB_KEY_TTL = 86400 # seconds
def _get_admob_public_key(key_id: str):
"""
Returns the Google ECDSA public-key object for the given key_id.
Fetches and caches the key list from gstatic; refreshes every 24h.
Returns None if the key_id is unknown.
"""
global _admob_key_cache, _admob_keys_fetched_at
now = time.time()
if now - _admob_keys_fetched_at > _ADMOB_KEY_TTL or not _admob_key_cache:
try:
resp = requests.get(ADMOB_KEYS_URL, timeout=5)
resp.raise_for_status()
data = resp.json()
new_cache = {}
for entry in data.get("keys", []):
kid = str(entry["keyId"])
pem = entry["pem"].encode()
new_cache[kid] = load_pem_public_key(pem)
_admob_key_cache = new_cache
_admob_keys_fetched_at = now
print(f"[ADMOB] Refreshed {len(new_cache)} public key(s) from Google.")
except Exception as e:
print(f"[ADMOB] WARNING: Could not refresh public keys: {e}")
# Fall through with stale cache rather than rejecting all valid callbacks
return _admob_key_cache.get(key_id)
def _verify_admob_signature(raw_query_string: str, signature_b64url: str, key_id: str) -> bool:
"""
Verifies an AdMob SSV ECDSA-SHA256 signature.
Google signs all query params EXCEPT 'signature' and 'key_id', in original order.
"""
try:
public_key = _get_admob_public_key(key_id)
if not public_key:
print("[ADMOB] Unknown key_id — rejecting callback.")
return False
# Reconstruct the signed payload by stripping signature + key_id from raw qs
parsed = urllib.parse.parse_qs(raw_query_string, keep_blank_values=True)
# Google signs query params in the exact order they appear in the URL.
# Use the raw string to preserve ordering — parse_qs loses it.
ordered_pairs = []
for pair in raw_query_string.split('&'):
if '=' not in pair:
continue
k, v = pair.split('=', 1)
if k in ('signature', 'key_id'):
continue
ordered_pairs.append(f"{k}={v}")
payload = '&'.join(ordered_pairs).encode('utf-8')
# Google uses URL-safe base64 (no padding) for the signature
sig_bytes = base64.urlsafe_b64decode(signature_b64url + '==')
public_key.verify(
sig_bytes,
payload,
ec.ECDSA(hashes.SHA256())
)
return True
except Exception as e:
print(f"[ADMOB] Signature verification failed: {e}")
return False
# ==============================================================================
# MANAGEMENT LOOP (The Hivemind — expiry + data-quota watchdog)
# ==============================================================================
def management_loop():
print(f"[HIVEMIND] Started. Tick every {CHECK_INTERVAL_SECONDS}s.")
init_wireguard()
while True:
try:
stats = get_wireguard_stats()
now = time.time()
with sessions_lock:
expired_devices = []
for device_id, session in list(active_sessions.items()):
ip = session["ip"]
# ── 1. Check expiry ───────────────────────────────────────
if now > session["expires_at"]:
print(f"[HIVEMIND] Session expired for {device_id} ({ip}). Removing peer.")
if session["is_throttled"]:
remove_throttle(ip)
remove_wg_peer(session["pubkey"])
release_ip(ip)
expired_devices.append(device_id)
continue
# ── 2. Check data quota ───────────────────────────────────
if ip in stats:
used_bytes = stats[ip]["total_bytes"] - session["baseline_bytes"]
if used_bytes > session["quota_bytes"] and not session["is_throttled"]:
print(f"[HIVEMIND] Data cap reached for {ip} ({used_bytes/1e9:.2f} GB used). Throttling.")
apply_throttle(ip)
session["is_throttled"] = True
for device_id in expired_devices:
del active_sessions[device_id]
except Exception as e:
print(f"[HIVEMIND] Unhandled error: {e}")
time.sleep(CHECK_INTERVAL_SECONDS)
# ==============================================================================
# LOW-LEVEL PLUMBING (awg, tc, IP pool, peer management)
# ==============================================================================
def run_cmd(cmd, ignore_errors=False):
"""Executes a shell command directly on the host (no Docker middleman)."""
# All commands run directly on the host against awg0.
@@ -177,25 +532,12 @@ def get_wireguard_stats():
return stats
import ipaddress
# ==============================================================================
# IPv6 HELPERS
# ==============================================================================
def ipv4_to_ipv6(ipv4):
"""Map 10.8.X.Y → fd42::X:Y (ULA for internal VPN routing, no NAT64 needed)."""
parts = ipv4.split('.')
return f"fd42::{parts[2]}:{parts[3]}"
# ==============================================================================
# IP POOL MANAGEMENT
# ==============================================================================
# The server subnet is 10.8.0.0/16, giving ~65,530 IPs for public use.
#60 THOUSAND OR 64 THOUSAND ARGUEMENT GOES HERE
AVAILABLE_IPS = {str(ip) for ip in ipaddress.IPv4Network('10.8.0.0/16').hosts()}
AVAILABLE_IPS.discard('10.8.0.1')
# We need a fallback if we somehow exhaust them, though unlikely
def allocate_ip():
"""Pops an available IP from the pre-generated pool."""
if not AVAILABLE_IPS:
@@ -224,320 +566,6 @@ def remove_wg_peer(pubkey):
print(f"[AWG] Ephemeral peer removed: {pubkey[:8]}...")
# ==============================================================================
# BACKGROUND MANAGEMENT LOOP (The Hivemind)
# ==============================================================================
def management_loop():
print(f"[HIVEMIND] Started. Tick every {CHECK_INTERVAL_SECONDS}s.")
init_wireguard()
while True:
try:
stats = get_wireguard_stats()
now = time.time()
with sessions_lock:
expired_devices = []
for device_id, session in list(active_sessions.items()):
ip = session["ip"]
# ── 1. Check expiry ───────────────────────────────────────
if now > session["expires_at"]:
print(f"[HIVEMIND] Session expired for {device_id} ({ip}). Removing peer.")
if session["is_throttled"]:
remove_throttle(ip)
remove_wg_peer(session["pubkey"])
release_ip(ip)
expired_devices.append(device_id)
continue
# ── 2. Check data quota ───────────────────────────────────
if ip in stats:
used_bytes = stats[ip]["total_bytes"] - session["baseline_bytes"]
if used_bytes > session["quota_bytes"] and not session["is_throttled"]:
print(f"[HIVEMIND] Data cap reached for {ip} ({used_bytes/1e9:.2f} GB used). Throttling.")
apply_throttle(ip)
session["is_throttled"] = True
for device_id in expired_devices:
del active_sessions[device_id]
except Exception as e:
print(f"[HIVEMIND] Unhandled error: {e}")
time.sleep(CHECK_INTERVAL_SECONDS)
# ==============================================================================
# SESSION LOGIC
# ==============================================================================
def _start_or_extend_session(device_id, client_pubkey, ad_type):
"""Core logic to provision or extend a session."""
if not re.match(r"^[A-Za-z0-9+/=]{43,44}$", client_pubkey):
return False, "Invalid WireGuard public key format"
now = time.time()
with sessions_lock:
if device_id in active_sessions and ad_type == 'bonus_ad':
# Extend existing session
session = active_sessions[device_id]
session["expires_at"] += (BONUS_AD_MINUTES * 60)
session["quota_bytes"] += BONUS_AD_BYTES
if session["is_throttled"]:
remove_throttle(session["ip"])
session["is_throttled"] = False
stats = get_wireguard_stats()
current_bytes = stats.get(session["ip"], {}).get("total_bytes", 0)
session["baseline_bytes"] = current_bytes
print(f"[SESSION] Bonus time added for {device_id} (IP: {session['ip']}).")
return True, "Bonus time and data added."
else:
# Create a brand new session (Main Ad)
if not validate_wg_pubkey(client_pubkey):
print(f"[SESSION] Rejected invalid pubkey from {device_id[:8]}...")
return False, "Invalid public key format."
existing = active_sessions.get(device_id)
if existing:
if existing["is_throttled"]:
remove_throttle(existing["ip"])
remove_wg_peer(existing["pubkey"])
release_ip(existing["ip"])
ipv4 = allocate_ip()
if not ipv4:
return False, "Server full! No available IP addresses."
ipv6 = ipv4_to_ipv6(ipv4)
add_wg_peer(client_pubkey, ipv4, ipv6)
# Fetch immediate stats to set baseline
# (Though brand new peers usually start at 0)
stats = get_wireguard_stats()
current_bytes = stats.get(ipv4, {}).get("total_bytes", 0)
active_sessions[device_id] = {
"ip": ipv4,
"ipv6": ipv6,
"pubkey": client_pubkey,
"expires_at": now + (MAIN_AD_MINUTES * 60),
"quota_bytes": MAIN_AD_BYTES,
"baseline_bytes": current_bytes,
"is_throttled": False,
}
print(f"[SESSION] Main session started for {device_id} (IP: {ipv4} / {ipv6}).")
return True, "Main session active."
# ==============================================================================
# ADMOB SERVER-TO-SERVER (SSV) VERIFICATION
# ==============================================================================
ADMOB_KEYS_URL = "https://www.gstatic.com/admob/reward/verifier-keys.json"
# Cache: { key_id_str: EllipticCurvePublicKey }
# Refreshed at most once every 24 hours so we don't hammer Google's CDN.
_admob_key_cache = {}
_admob_keys_fetched_at = 0.0
_ADMOB_KEY_TTL = 86400 # seconds
def _get_admob_public_key(key_id: str):
"""
Returns the Google ECDSA public-key object for the given key_id.
Fetches and caches the key list from gstatic; refreshes every 24h.
Returns None if the key_id is unknown.
"""
global _admob_key_cache, _admob_keys_fetched_at
now = time.time()
if now - _admob_keys_fetched_at > _ADMOB_KEY_TTL or not _admob_key_cache:
try:
resp = requests.get(ADMOB_KEYS_URL, timeout=5)
resp.raise_for_status()
data = resp.json()
new_cache = {}
for entry in data.get("keys", []):
kid = str(entry["keyId"])
pem = entry["pem"].encode()
new_cache[kid] = load_pem_public_key(pem)
_admob_key_cache = new_cache
_admob_keys_fetched_at = now
print(f"[ADMOB] Refreshed {len(new_cache)} public key(s) from Google.")
except Exception as e:
print(f"[ADMOB] WARNING: Could not refresh public keys: {e}")
# Fall through with stale cache rather than rejecting all valid callbacks
return _admob_key_cache.get(key_id)
def _verify_admob_signature(raw_query_string: str, signature_b64url: str, key_id: str) -> bool:
"""
Verifies an AdMob SSV ECDSA-SHA256 signature.
Google signs all query params EXCEPT 'signature' and 'key_id', in original order.
"""
try:
# 1. Rebuild the signed message: all params except signature & key_id
params = urllib.parse.parse_qsl(raw_query_string, keep_blank_values=True)
filtered = [(k, v) for k, v in params if k not in ("signature", "key_id")]
message = urllib.parse.urlencode(filtered).encode("utf-8")
# 2. Base64url-decode the signature (add missing padding if needed)
padding = 4 - len(signature_b64url) % 4
sig_bytes = base64.urlsafe_b64decode(signature_b64url + ("=" * (padding % 4)))
# 3. Fetch the matching public key
pub_key = _get_admob_public_key(key_id)
if pub_key is None:
print(f"[ADMOB] Unknown key_id: {key_id}. Rejecting.")
return False
# 4. Verify — raises InvalidSignature on failure
pub_key.verify(sig_bytes, message, ec.ECDSA(hashes.SHA256()))
return True
except Exception as e:
print(f"[ADMOB] Signature verification failed: {e}")
return False
@app.route('/api/admob/callback', methods=['GET'])
def admob_callback():
"""
Google AdMob SSV callback — called server-to-server when a rewarded ad completes.
The Android client never touches this endpoint; Google calls it directly.
custom_data (JSON, set by the app before showing the ad):
{ "device_id": "...", "public_key": "...", "ad_type": "main_ad"|"bonus_ad" }
"""
try:
# ======================================================================
# ⚠️ ADMOB BYPASS (TEMPORARY FOR APP REVIEW)
# DELETE THIS ENTIRE BLOCK WHEN YOU WANT TO ENABLE REAL ADS
# ======================================================================
custom_data_str = request.args.get('custom_data')
if not custom_data_str:
return "OK", 200
# ======================================================================
# ======================================================================
# ✅ REAL ADMOB CODE
# UNCOMMENT THIS ENTIRE BLOCK WHEN YOU WANT TO ENABLE REAL ADS
# ======================================================================
# signature = request.args.get('signature')
# key_id = request.args.get('key_id')
# custom_data_str = request.args.get('custom_data')
#
# # Google sends a verification ping with signature+key_id but no custom_data
# if not custom_data_str:
# return "OK", 200 # Verification ping from Google dashboard
#
# if not all([signature, key_id]):
# return "Missing parameters", 400
#
# raw_qs = request.query_string.decode("utf-8")
# if not _verify_admob_signature(raw_qs, signature, key_id):
# print("[ADMOB] Rejected callback — invalid signature.")
# return "Forbidden", 403
# ======================================================================
custom_data = json.loads(custom_data_str)
device_id = custom_data.get('device_id')
client_pubkey = custom_data.get('public_key')
if not device_id or not client_pubkey:
return "Invalid custom_data payload", 400
ad_type = custom_data.get('ad_type', 'main_ad')
success, msg = _start_or_extend_session(device_id, client_pubkey, ad_type)
return ("OK", 200) if success else (msg, 500)
except Exception as e:
print(f"[ADMOB] SSV Error: {e}")
return "Internal Error", 500
# ==============================================================================
# FLASK API (APP POLLING)
# ==============================================================================
@app.route('/api/session/status', methods=['GET'])
def session_status():
"""
Query: ?device_id=esf-xxx
Returns current session state so the Android app can construct its AmneziaWG config.
"""
device_id = request.args.get('device_id')
if not device_id:
return jsonify({"error": "Missing query parameter: device_id"}), 400
with sessions_lock:
session = active_sessions.get(device_id)
if not session:
return jsonify({"active": False, "message": "No session found."}), 404
# Bulletproof fallback: If server public key is missing, try fetching it right now
global SERVER_PUBKEY
if not SERVER_PUBKEY:
pubkey = run_cmd("awg show awg0 public-key")
if pubkey:
SERVER_PUBKEY = pubkey
print(f"[AWG] Dynamic Server Public Key cached from awg0: {SERVER_PUBKEY}")
else:
SERVER_PUBKEY = SERVER_PUBKEY_FALLBACK or "server key="
stats = get_wireguard_stats()
current_bytes = stats.get(session["ip"], {}).get("total_bytes", 0)
used_bytes = max(0, current_bytes - session["baseline_bytes"])
remaining_data = max(0, session["quota_bytes"] - used_bytes)
remaining_secs = max(0, session["expires_at"] - time.time())
return jsonify({
"active": remaining_secs > 0,
"client_ip": session["ip"],
"client_ipv6": session.get("ipv6", ""),
"server_pubkey": SERVER_PUBKEY,
"is_throttled": session["is_throttled"],
"expires_in_seconds": int(remaining_secs),
"quota_bytes": session["quota_bytes"],
"used_bytes": used_bytes,
"remaining_bytes": remaining_data,
})
@app.route('/api/session/stop', methods=['POST'])
def session_stop():
"""Allows the app to explicitly tear down its session on disconnect."""
data = request.get_json(silent=True)
device_id = data.get('device_id') if data else None
if device_id:
with sessions_lock:
session = active_sessions.pop(device_id, None)
if session:
remove_wg_peer(session["pubkey"])
if session["is_throttled"]:
remove_throttle(session["ip"])
release_ip(session["ip"])
print(f"[API] Explicit stop for {device_id}.")
return jsonify({"success": True})
# ==============================================================================
# ENTRY POINT
# ==============================================================================