Security Configuration - FreeTAKServer

Overview

FreeTAKServer implements multiple layers of security:

SSL/TLS Encryption: Secure communications using X.509 certificates
Client Certificate Authentication: Mutual TLS authentication for TAK clients
Token-Based Authentication: Bearer tokens for REST API access
Certificate Revocation: Certificate Revocation List (CRL) support
User Management: System and API user authentication

SSL/TLS Configuration

SSL/TLS encryption is essential for protecting tactical data in production deployments.

Certificate Paths

certsPath

string

default:"/opt/fts/certs"

Root directory for all certificates and keysEnvironment variable: FTS_CERTS_PATHYAML: Filesystem.FTS_CERTS_PATH

Server Certificate

keyDir

string

default:"/opt/fts/certs/server.key"

Path to server private key (PEM format)Environment variable: FTS_SERVER_KEYDIRYAML: Certs.FTS_SERVER_KEYDIR

pemDir

string

default:"/opt/fts/certs/server.pem"

Path to server certificate (PEM format)Environment variable: FTS_SERVER_PEMDIRYAML: Certs.FTS_SERVER_PEMDIR

unencryptedKey

string

default:"/opt/fts/certs/server.key.unencrypted"

Path to unencrypted server key (used internally by services)Environment variable: FTS_UNENCRYPTED_KEYDIRYAML: Certs.FTS_UNENCRYPTED_KEYDIR

p12Dir

string

default:"/opt/fts/certs/server.p12"

Path to PKCS#12 format certificate bundle (includes private key and certificate)Environment variable: FTS_SERVER_P12DIRYAML: Certs.FTS_SERVER_P12DIR

Certificate Authority (CA)

string

default:"/opt/fts/certs/ca.pem"

Path to Certificate Authority certificateEnvironment variable: FTS_CADIRYAML: Certs.FTS_CADIR

CAkey

string

default:"/opt/fts/certs/ca.key"

Path to Certificate Authority private key (for signing client certificates)Environment variable: FTS_CAKEYDIRYAML: Certs.FTS_CAKEYDIR

Test Client Certificates

testPem

string

default:"/opt/fts/certs/server.key"

Path to test client certificateEnvironment variable: FTS_TESTCLIENT_PEMDIRYAML: Certs.FTS_TESTCLIENT_PEMDIR

testKey

string

default:"/opt/fts/certs/server.pem"

Path to test client private keyEnvironment variable: FTS_TESTCLIENT_KEYDIRYAML: Certs.FTS_TESTCLIENT_KEYDIR

Client Certificate Password

password

string

default:"supersecret"

Password used when generating client certificate packages (P12 files)Environment variable: FTS_CLIENT_CERT_PASSWORDYAML: Certs.FTS_CLIENT_CERT_PASSWORD

Change the default client certificate password in production! This password protects client certificate files.

Client Certificate Packages

ClientPackages

string

default:"/opt/fts/certs/clientPackages"

Directory for storing generated client certificate packagesEnvironment variable: FTS_CLIENT_PACKAGES_PATHYAML: Filesystem.FTS_CLIENT_PACKAGES_PATH

Certificate Revocation

CRLFile

string

default:"/opt/fts/certs/FTS_CRL.json"

Path to Certificate Revocation List (CRL) file in JSON formatEnvironment variable: FTS_CRLDIRYAML: Certs.FTS_CRLDIR

The CRL allows administrators to revoke compromised or unauthorized client certificates.

CRL File Format

{
  "revoked_certificates": [
    {
      "serial_number": "1A2B3C4D5E6F",
      "revocation_date": "2024-03-04T10:00:00Z",
      "reason": "compromised"
    },
    {
      "serial_number": "9F8E7D6C5B4A",
      "revocation_date": "2024-03-03T15:30:00Z",
      "reason": "privilege_withdrawn"
    }
  ]
}

Federation Security

federationCert

string

default:"/opt/fts/certs/server.pem"

Certificate used for federation connections with other TAK serversEnvironment variable: FTS_FEDERATION_CERTDIRYAML: Certs.FTS_FEDERATION_CERTDIR

federationKey

string

default:"/opt/fts/certs/server.key"

Private key for federation connectionsEnvironment variable: FTS_FEDERATION_KEYDIRYAML: Certs.FTS_FEDERATION_KEYDIR

federationKeyPassword

string

default:"defaultpass"

Password for the federation private keyEnvironment variable: FTS_FEDERATION_KEYPASSYAML: Certs.FTS_FEDERATION_KEYPASS

REST API Authentication

The REST API uses HTTP Bearer token authentication.

Secret Key

SecretKey

string

default:"vnkdjnfjknfl1232#"

Secret key for cryptographic operations, session management, and token signingEnvironment variable: FTS_SECRET_KEYYAML: System.FTS_SECRET_KEY

The default SecretKey MUST be changed in production! Generate a cryptographically secure random string.

WebSocket Key

websocketkey

string

default:"YourWebsocketKey"

Authentication key for WebSocket connectionsEnvironment variable: FTS_WEBSOCKET_KEYYAML: Certs.FTS_WEBSOCKET_KEY

Authentication Implementation

From FreeTAKServer/services/rest_api_service/controllers/authentication.py:

from flask_httpauth import HTTPTokenAuth

auth = HTTPTokenAuth(scheme='Bearer')

@auth.verify_token
def verify_token(token):
    # Verify against APIUser table
    output = dbController.query_APIUser(query=f'token = "{token}"')
    if output:
        return output[0].Username
    
    # Verify against SystemUser table
    output = dbController.query_systemUser(query=f'token = "{token}"')
    if output:
        # Log API call
        dbController.create_APICall(
            user_id=output[0].uid,
            timestamp=datetime.now(),
            content=request.data,
            endpoint=request.base_url
        )
        return output[0].name

User Types

SystemUser: Administrative users with full access

Stored in SystemUser table
Default admin user created on first run
All API calls are logged

APIUser: Application users with limited access

Stored in APIUser table
Created via user management API
No automatic logging

CLI Access Control

CLIIP

string

default:"127.0.0.1"

IP address for CLI access interface

AllowCLIIPs

list

default:"[127.0.0.1]"

Whitelist of IP addresses allowed to access the CLI interfaceEnvironment variable: FTS_CLI_WHITELIST (colon or comma separated)YAML: Addresses.FTS_CLI_WHITELIST

Example:

Addresses:
  FTS_CLI_WHITELIST: ["127.0.0.1", "192.168.1.0/24", "10.0.0.5"]

SSL/TLS Timeouts

From FreeTAKServer/core/configuration/ReceiveConnectionsConstants.py:

WRAP_SSL_TIMEOUT = 1.0  # Timeout for SSL handshake
SSL_SOCK_TIMEOUT = 60   # Timeout for SSL socket operations

These values control SSL/TLS connection behavior:

WRAP_SSL_TIMEOUT: Maximum time to complete SSL handshake
SSL_SOCK_TIMEOUT: Maximum idle time for established SSL connections

Security Configuration Examples

Development Environment

System:
  FTS_SECRET_KEY: "dev-secret-key-not-for-production"

Addresses:
  FTS_COT_PORT: 8087  # Unencrypted for testing
  FTS_API_ADDRESS: "127.0.0.1"  # Local only
  FTS_CLI_WHITELIST: ["127.0.0.1"]

Certs:
  FTS_CLIENT_CERT_PASSWORD: "test123"

Development environments can use unencrypted connections for convenience, but production deployments should always use SSL/TLS.

Production Environment

System:
  FTS_SECRET_KEY: "Km9pR3tX8vL2nQ5wY7aE1cH4uD6gF0iJ3bN8mP5sT7zA"  # Strong random key

Addresses:
  FTS_SSLCOT_PORT: 8089  # SSL only
  FTS_HTTPS_TAK_API_PORT: 8443  # HTTPS only
  FTS_API_ADDRESS: "0.0.0.0"
  FTS_CLI_WHITELIST: ["10.0.0.0/8", "192.168.1.100"]  # Restricted IPs

Certs:
  FTS_CERTS_PATH: "/opt/fts/certs"
  FTS_SERVER_KEYDIR: "/opt/fts/certs/production-server.key"
  FTS_SERVER_PEMDIR: "/opt/fts/certs/production-server.pem"
  FTS_CADIR: "/opt/fts/certs/production-ca.pem"
  FTS_CAKEYDIR: "/opt/fts/certs/production-ca.key"
  FTS_CLIENT_CERT_PASSWORD: "Zx9C7v5B3nM1qW8eR4tY6uI0oP2aS5dF"  # Strong password
  FTS_CRLDIR: "/opt/fts/certs/production-crl.json"
  FTS_FEDERATION_CERTDIR: "/opt/fts/certs/federation.pem"
  FTS_FEDERATION_KEYDIR: "/opt/fts/certs/federation.key"
  FTS_FEDERATION_KEYPASS: "H4gF7jK9lP2mN5qR8tW1yU3xC6vB0zA"  # Strong password

Certificate Generation

Generate CA Certificate

# Generate CA private key
openssl genrsa -out /opt/fts/certs/ca.key 4096

# Generate CA certificate
openssl req -new -x509 -key /opt/fts/certs/ca.key \
  -out /opt/fts/certs/ca.pem -days 3650 \
  -subj "/C=US/ST=State/L=City/O=Organization/CN=FTS-CA"

Generate Server Certificate

# Generate server private key
openssl genrsa -out /opt/fts/certs/server.key 2048

# Generate certificate signing request
openssl req -new -key /opt/fts/certs/server.key \
  -out /opt/fts/certs/server.csr \
  -subj "/C=US/ST=State/L=City/O=Organization/CN=fts.example.com"

# Sign with CA
openssl x509 -req -in /opt/fts/certs/server.csr \
  -CA /opt/fts/certs/ca.pem -CAkey /opt/fts/certs/ca.key \
  -CAcreateserial -out /opt/fts/certs/server.pem -days 365

# Create unencrypted key copy
cp /opt/fts/certs/server.key /opt/fts/certs/server.key.unencrypted

Generate Client Certificate

# Generate client private key
openssl genrsa -out /opt/fts/certs/client.key 2048

# Generate certificate signing request
openssl req -new -key /opt/fts/certs/client.key \
  -out /opt/fts/certs/client.csr \
  -subj "/C=US/ST=State/L=City/O=Organization/CN=client-001"

# Sign with CA
openssl x509 -req -in /opt/fts/certs/client.csr \
  -CA /opt/fts/certs/ca.pem -CAkey /opt/fts/certs/ca.key \
  -CAcreateserial -out /opt/fts/certs/client.pem -days 365

# Create P12 bundle for distribution
openssl pkcs12 -export -out /opt/fts/certs/client.p12 \
  -inkey /opt/fts/certs/client.key \
  -in /opt/fts/certs/client.pem \
  -certfile /opt/fts/certs/ca.pem \
  -password pass:supersecret

User Management

Create API User

from FreeTAKServer.core.persistence.DatabaseController import DatabaseController
import secrets

db = DatabaseController()

# Generate secure token
token = secrets.token_urlsafe(32)

# Create API user
db.create_APIUser(
    Username="api_operator",
    Password="hashed_password_here",  # Use proper password hashing
    token=token
)

Create System User

db.create_systemUser(
    uid=str(uuid4()),
    name="operator_01",
    password="hashed_password_here",
    token=secrets.token_urlsafe(32),
    device_type="desktop"
)

Using API Authentication

# Authenticate and receive token
curl -X POST https://fts.example.com:19023/api/login \
  -H "Content-Type: application/json" \
  -d '{"username":"api_operator","password":"securepass"}'

# Use token for subsequent requests
curl -X GET https://fts.example.com:19023/api/users \
  -H "Authorization: Bearer your-token-here"

Certificate Revocation Process

Add Certificate to CRL

import json
from datetime import datetime

# Read existing CRL
with open('/opt/fts/certs/FTS_CRL.json', 'r') as f:
    crl = json.load(f)

# Add revoked certificate
crl['revoked_certificates'].append({
    'serial_number': '1A2B3C4D5E6F',
    'revocation_date': datetime.utcnow().isoformat() + 'Z',
    'reason': 'compromised'
})

# Write updated CRL
with open('/opt/fts/certs/FTS_CRL.json', 'w') as f:
    json.dump(crl, f, indent=2)

Revocation Reasons

unspecified: No specific reason given
key_compromise: Private key has been compromised
ca_compromise: CA has been compromised
affiliation_changed: User’s affiliation has changed
superseded: Certificate has been replaced
cessation_of_operation: Certificate is no longer needed
privilege_withdrawn: User privileges have been revoked

File Permissions

Proper filesystem permissions are critical for security:

# Set ownership
sudo chown -R fts:fts /opt/fts/certs

# Secure private keys (read-only for owner)
sudo chmod 400 /opt/fts/certs/*.key
sudo chmod 400 /opt/fts/certs/ca.key

# Secure certificates (readable by group)
sudo chmod 444 /opt/fts/certs/*.pem
sudo chmod 444 /opt/fts/certs/ca.pem

# Secure client packages directory
sudo chmod 750 /opt/fts/certs/clientPackages

# Secure CRL file
sudo chmod 644 /opt/fts/certs/FTS_CRL.json

Security Best Practices

Never commit certificates, private keys, or passwords to version control systems.

Always change default passwords and secret keys before deploying to production.

Generate cryptographically secure random strings for SecretKey, password, and federationKeyPassword using openssl rand -base64 32 or similar tools.

Mandatory Production Security Measures

Change all default passwords and keys
- SecretKey
- password (client certificate password)
- federationKeyPassword
- Default admin user credentials
Use SSL/TLS encryption
- Enable SSL CoT service (port 8089)
- Enable HTTPS TAK API (port 8443)
- Disable unencrypted services in production
Implement certificate management
- Generate unique certificates for production
- Use strong key lengths (2048-bit minimum, 4096-bit recommended)
- Set appropriate certificate expiration dates
- Implement certificate rotation procedures
Configure access controls
- Restrict CLI access with AllowCLIIPs
- Use firewall rules to limit service access
- Implement network segmentation
Secure filesystem
- Set restrictive permissions on certificate files
- Protect private keys (chmod 400)
- Regular security audits of file permissions
Monitor and log
- Enable API call logging
- Monitor certificate expiration dates
- Review access logs regularly
- Implement intrusion detection
Certificate revocation
- Maintain current CRL
- Implement certificate revocation procedures
- Test revocation process regularly
Backup security
- Encrypt backups containing certificates
- Secure backup storage locations
- Test backup restoration procedures
Update and patch
- Keep FreeTAKServer updated
- Monitor security advisories
- Apply security patches promptly
Physical security
- Secure server physical access
- Protect certificate storage media
- Implement secure key disposal procedures

Security Checklist

Before deploying to production:

Get Started

Core Concepts

Guides

Configuration

​Overview

​SSL/TLS Configuration

​Certificate Paths

​Server Certificate

​Certificate Authority (CA)

​Test Client Certificates

​Client Certificate Password

​Client Certificate Packages

​Certificate Revocation

​CRL File Format

​Federation Security

​REST API Authentication

​Secret Key

​WebSocket Key

​Authentication Implementation

​User Types

​CLI Access Control

​SSL/TLS Timeouts

​Security Configuration Examples

​Development Environment

​Production Environment

​Certificate Generation

​Generate CA Certificate

​Generate Server Certificate

​Generate Client Certificate

​User Management

​Create API User

​Create System User

​Using API Authentication

​Certificate Revocation Process

​Add Certificate to CRL

​Revocation Reasons

​File Permissions

​Security Best Practices

​Mandatory Production Security Measures

​Security Checklist

Build docs developers (and LLMs) love

Overview

SSL/TLS Configuration

Certificate Paths

Server Certificate

Certificate Authority (CA)

Test Client Certificates

Client Certificate Password

Client Certificate Packages

Certificate Revocation

CRL File Format

Federation Security

REST API Authentication

Secret Key

WebSocket Key

Authentication Implementation

User Types

CLI Access Control

SSL/TLS Timeouts

Security Configuration Examples

Development Environment

Production Environment

Certificate Generation

Generate CA Certificate

Generate Server Certificate

Generate Client Certificate

User Management

Create API User

Create System User

Using API Authentication

Certificate Revocation Process

Add Certificate to CRL

Revocation Reasons

File Permissions

Security Best Practices

Mandatory Production Security Measures

Security Checklist