import json import base64 from datetime import datetime def handler(event, context): cookies = event.get('cookies', []) auth_token = None for cookie in cookies: if cookie.startswith('__Host-auth_session='): auth_token = cookie.split('=', 1)[1] break if not auth_token: return { 'statusCode': 200, 'headers': { 'Content-Type': 'text/html', 'Content-Security-Policy': "default-src 'none'; script-src 'unsafe-inline'; style-src 'unsafe-inline'", }, 'body': '

No JWT Found

No auth_session cookie present.

' } try: parts = auth_token.split('.') if len(parts) != 3: raise ValueError('Invalid JWT format') header = json.loads(base64.urlsafe_b64decode(parts[0] + '==')) payload = json.loads(base64.urlsafe_b64decode(parts[1] + '==')) # Format timestamps nbf_time = datetime.fromtimestamp(payload.get('nbf', 0)).strftime('%Y-%m-%d %H:%M:%S') if 'nbf' in payload else 'N/A' exp_time = datetime.fromtimestamp(payload.get('exp', 0)).strftime('%Y-%m-%d %H:%M:%S') if 'exp' in payload else 'N/A' html = f''' JWT Decoder

JWT Token Details

Not Before: {nbf_time} UTC

Expires: {exp_time} UTC

Header

{json.dumps(header, indent=2)}

Payload

{json.dumps(payload, indent=2)}

Signature

{parts[2]}

''' return { 'statusCode': 200, 'headers': { 'Content-Type': 'text/html', 'Content-Security-Policy': "default-src 'none'; script-src 'unsafe-inline'; style-src 'unsafe-inline'", }, 'body': html } except Exception as e: return { 'statusCode': 200, 'headers': { 'Content-Type': 'text/html', 'Content-Security-Policy': "default-src 'none'; script-src 'unsafe-inline'; style-src 'unsafe-inline'", }, 'body': f'

Error Decoding JWT

{str(e)}

' }