# Portal Server Security Analysis

## Executive Summary

The Portal Server implements a multi-layered security approach for handling sensitive KYC verification and payment processing operations. This document provides a comprehensive analysis of the current security posture, identifies potential vulnerabilities, and recommends security enhancements.

## Current Security Implementation

### ✅ Implemented Security Features

#### 1. **Feature-Based CORS Configuration**
- **Development Mode**: Permissive CORS for local development
- **Production Mode**: Strict origin restrictions with configurable allowed domains
- **Implementation**: [`src/server.rs:113-150`](../freezone/portal-server/src/server.rs:113)

```rust
#[cfg(feature = "prod")]
{
    let mut cors = CorsLayer::new()
        .allow_methods([http::Method::GET, http::Method::POST])
        .allow_headers(Any);
    // Restricted to configured origins only
}
```

#### 2. **Webhook Signature Verification**
- **Stripe Webhooks**: Signature validation using `stripe-signature` header
- **Identify Webhooks**: Signature validation using `x-identify-signature` header
- **Implementation**: [`src/handlers.rs:92-116`](../freezone/portal-server/src/handlers.rs:92) and [`src/handlers.rs:252-264`](../freezone/portal-server/src/handlers.rs:252)

#### 3. **Input Validation**
- **Request Validation**: All endpoints validate required fields
- **Configuration Validation**: Server startup validates required API keys
- **Implementation**: [`src/server.rs:96-110`](../freezone/portal-server/src/server.rs:96)

#### 4. **Environment Variable Protection**
- **Sensitive Data**: API keys stored in environment variables
- **Configuration**: Support for `.env` files with validation
- **Implementation**: [`src/config.rs:33-59`](../freezone/portal-server/src/config.rs:33)

#### 5. **Error Handling**
- **Information Disclosure**: Controlled error responses without sensitive data exposure
- **Logging**: Structured logging with appropriate log levels
- **Implementation**: [`src/handlers.rs:47-64`](../freezone/portal-server/src/handlers.rs:47)

## Security Architecture

```mermaid
graph TB
    subgraph "Client Applications"
        A[Portal WASM App]
        B[Admin Dashboard]
    end
    
    subgraph "Portal Server Security Layers"
        C[CORS Layer]
        D[Input Validation]
        E[Request Handlers]
        F[Service Layer]
    end
    
    subgraph "External Services"
        G[Stripe API]
        H[Identify API]
    end
    
    subgraph "Security Controls"
        I[Webhook Signature Verification]
        J[Environment Variable Protection]
        K[Error Handling]
        L[Logging & Monitoring]
    end
    
    A --> C
    B --> C
    C --> D
    D --> E
    E --> F
    F --> G
    F --> H
    
    I --> E
    J --> F
    K --> E
    L --> E
```

## Threat Model

### High-Risk Threats

#### 1. **API Key Compromise**
- **Risk**: Unauthorized access to Stripe/Identify services
- **Impact**: Financial fraud, data breach, service disruption
- **Mitigation**: Environment variable protection, key rotation

#### 2. **Webhook Spoofing**
- **Risk**: Malicious webhook payloads bypassing verification
- **Impact**: False payment confirmations, data manipulation
- **Mitigation**: Signature verification (partially implemented)

#### 3. **Cross-Origin Attacks**
- **Risk**: Unauthorized cross-origin requests
- **Impact**: Data theft, CSRF attacks
- **Mitigation**: Feature-based CORS restrictions

### Medium-Risk Threats

#### 4. **Data Injection Attacks**
- **Risk**: Malicious input in payment/KYC data
- **Impact**: Data corruption, service disruption
- **Mitigation**: Input validation, sanitization

#### 5. **Rate Limiting Bypass**
- **Risk**: API abuse, DoS attacks
- **Impact**: Service degradation, increased costs
- **Mitigation**: Not currently implemented

#### 6. **Information Disclosure**
- **Risk**: Sensitive data in logs/errors
- **Impact**: Data breach, compliance violations
- **Mitigation**: Controlled error responses

## Security Gaps & Recommendations

### 🔴 Critical Security Gaps

#### 1. **Incomplete Webhook Signature Verification**
**Current State**: Placeholder implementation
```rust
// src/services.rs:83-90
pub fn verify_webhook_signature(&self, _payload: &str, signature: &str) -> bool {
    // For now, we'll just check that the signature is not empty
    !signature.is_empty()
}
```

**Recommendation**: Implement proper HMAC-SHA256 verification
```rust
use hmac::{Hmac, Mac};
use sha2::Sha256;

pub fn verify_webhook_signature(&self, payload: &str, signature: &str, secret: &str) -> bool {
    let mut mac = Hmac::<Sha256>::new_from_slice(secret.as_bytes()).unwrap();
    mac.update(payload.as_bytes());
    let expected = mac.finalize().into_bytes();
    let provided = hex::decode(signature.trim_start_matches("sha256=")).unwrap_or_default();
    expected.as_slice() == provided.as_slice()
}
```

#### 2. **No API Authentication**
**Current State**: All endpoints are publicly accessible
**Recommendation**: Implement API key authentication middleware
```rust
async fn api_key_middleware(
    headers: HeaderMap,
    request: Request<Body>,
    next: Next<Body>
) -> Result<Response, StatusCode> {
    let api_key = headers.get("x-api-key")
        .and_then(|v| v.to_str().ok())
        .ok_or(StatusCode::UNAUTHORIZED)?;
    
    if !validate_api_key(api_key) {
        return Err(StatusCode::UNAUTHORIZED);
    }
    
    Ok(next.run(request).await)
}
```

#### 3. **In-Memory Session Storage**
**Current State**: Verification sessions stored in HashMap
**Security Risk**: Data loss on restart, no persistence, no encryption
**Recommendation**: Implement encrypted database storage with TTL

### 🟡 Important Security Enhancements

#### 4. **Rate Limiting**
**Recommendation**: Implement per-IP and per-endpoint rate limiting
```rust
use tower_governor::{GovernorLayer, GovernorConfigBuilder};

let governor_conf = GovernorConfigBuilder::default()
    .per_second(10)
    .burst_size(20)
    .finish()
    .unwrap();

router.layer(GovernorLayer::new(&governor_conf))
```

#### 5. **Request Size Limits**
**Recommendation**: Add request body size limits
```rust
use tower_http::limit::RequestBodyLimitLayer;

router.layer(RequestBodyLimitLayer::new(1024 * 1024)) // 1MB limit
```

#### 6. **Security Headers**
**Recommendation**: Add security headers middleware
```rust
use tower_http::set_header::SetResponseHeaderLayer;

router.layer(SetResponseHeaderLayer::overriding(
    header::X_CONTENT_TYPE_OPTIONS,
    HeaderValue::from_static("nosniff")
))
```

## Compliance Considerations

### PCI DSS Compliance (Payment Processing)
- ✅ **Requirement 1**: Firewall configuration (network level)
- ✅ **Requirement 2**: Default passwords changed (API keys)
- ⚠️ **Requirement 3**: Cardholder data protection (delegated to Stripe)
- ❌ **Requirement 4**: Encryption in transit (HTTPS required)
- ❌ **Requirement 6**: Secure development (needs security testing)
- ❌ **Requirement 8**: Access control (no authentication implemented)
- ❌ **Requirement 10**: Logging and monitoring (basic logging only)
- ❌ **Requirement 11**: Security testing (not implemented)

### GDPR Compliance (Data Protection)
- ⚠️ **Data Minimization**: Only collect necessary KYC data
- ❌ **Data Encryption**: No encryption at rest implemented
- ⚠️ **Data Retention**: No automatic data deletion
- ❌ **Audit Logging**: Limited audit trail
- ❌ **Data Subject Rights**: No data export/deletion endpoints

## Security Testing Strategy

### 1. **Automated Security Testing**
```bash
# Dependency vulnerability scanning
cargo audit

# Static analysis
cargo clippy -- -W clippy::all

# Security-focused linting
cargo semver-checks
```

### 2. **Penetration Testing Checklist**
- [ ] CORS bypass attempts
- [ ] Webhook signature bypass
- [ ] Input validation bypass
- [ ] Rate limiting bypass
- [ ] Information disclosure
- [ ] Authentication bypass
- [ ] Authorization bypass

### 3. **Security Monitoring**
```rust
// Implement security event logging
use tracing::{warn, error};

// Log security events
warn!(
    user_id = %user_id,
    ip_address = %client_ip,
    event = "failed_authentication",
    "Authentication attempt failed"
);
```

## Incident Response Plan

### 1. **Security Incident Classification**
- **P0 Critical**: API key compromise, data breach
- **P1 High**: Service disruption, authentication bypass
- **P2 Medium**: Rate limiting bypass, information disclosure
- **P3 Low**: Security configuration issues

### 2. **Response Procedures**
1. **Immediate Response** (0-1 hour)
   - Isolate affected systems
   - Revoke compromised credentials
   - Enable emergency rate limiting

2. **Investigation** (1-24 hours)
   - Analyze logs and traces
   - Determine scope of impact
   - Document findings

3. **Recovery** (24-72 hours)
   - Implement fixes
   - Restore services
   - Update security controls

4. **Post-Incident** (1-2 weeks)
   - Conduct post-mortem
   - Update security procedures
   - Implement preventive measures

## Security Configuration Guide

### Production Deployment Checklist

#### Environment Configuration
```bash
# Required security environment variables
STRIPE_SECRET_KEY=sk_live_...           # Production Stripe key
STRIPE_WEBHOOK_SECRET=whsec_...         # Webhook verification
IDENTIFY_API_KEY=identify_prod_...      # Production Identify key
CORS_ORIGINS=https://app.freezone.com   # Restrict origins
```

#### Build Configuration
```bash
# Production build with security features
cargo build --release --features prod --no-default-features
```

#### Runtime Security
```bash
# Run with restricted permissions
./portal-server \
  --host 0.0.0.0 \
  --port 3001 \
  --from-env \
  --cors-origins "https://app.freezone.com,https://portal.freezone.com"
```

### Development Security
```bash
# Development build (permissive CORS)
cargo build --features dev

# Local development
./portal-server --from-env --verbose --cors-origins "*"
```

## Security Metrics & Monitoring

### Key Security Metrics
1. **Authentication Failures**: Failed API key validations
2. **Webhook Verification Failures**: Invalid signatures
3. **Rate Limit Violations**: Exceeded request limits
4. **CORS Violations**: Blocked cross-origin requests
5. **Input Validation Failures**: Malformed requests

### Monitoring Implementation
```rust
use prometheus::{Counter, Histogram, register_counter, register_histogram};

lazy_static! {
    static ref AUTH_FAILURES: Counter = register_counter!(
        "auth_failures_total",
        "Total number of authentication failures"
    ).unwrap();
    
    static ref REQUEST_DURATION: Histogram = register_histogram!(
        "request_duration_seconds",
        "Request duration in seconds"
    ).unwrap();
}
```

## Conclusion

The Portal Server implements foundational security controls but requires significant enhancements for production deployment. Priority should be given to:

1. **Immediate**: Implement proper webhook signature verification
2. **Short-term**: Add API authentication and rate limiting
3. **Medium-term**: Implement persistent encrypted storage
4. **Long-term**: Achieve PCI DSS and GDPR compliance

Regular security assessments and penetration testing should be conducted to maintain security posture as the system evolves.

---

**Document Version**: 1.0  
**Last Updated**: 2025-06-29  
**Next Review**: 2025-09-29  
**Classification**: Internal Use Only