Security Policy

Supported Versions

stream library is currently in active development (0.x versions). We provide security updates for the following versions:

Version	Supported
0.1.x	✅
< 0.1.0	❌

Future stable releases (v1.0+) will follow semantic versioning with LTS support.

Reporting a Vulnerability

We take security seriously. If you discover a security vulnerability in stream, please report it responsibly.

How to Report

DO NOT open a public GitHub issue for security vulnerabilities.

Instead, please report security issues by:

Private Security Advisory (preferred): https://github.com/coregx/stream/security/advisories/new
Email to maintainers: Create a private GitHub issue or contact via discussions

What to Include

Please include the following information in your report:

Description of the vulnerability
Steps to reproduce the issue (include proof-of-concept if applicable)
Affected versions (which versions are impacted)
Potential impact (DoS, information disclosure, RCE, etc.)
Suggested fix (if you have one)
Your contact information (for follow-up questions)

Response Timeline

Initial Response: Within 48-72 hours
Triage & Assessment: Within 1 week
Fix & Disclosure: Coordinated with reporter

We aim to:

Acknowledge receipt within 72 hours
Provide an initial assessment within 1 week
Work with you on a coordinated disclosure timeline
Credit you in the security advisory (unless you prefer to remain anonymous)

Security Considerations for Real-Time Communications

Real-time communication libraries (SSE and WebSocket) handle long-lived connections and untrusted data streams, introducing unique security risks.

1. WebSocket Handshake Attacks

Risk: Malicious handshake requests can exploit upgrade vulnerabilities.

Attack Vectors:

Invalid Sec-WebSocket-Key values
Missing required headers
Origin header spoofing
Subprotocol injection

Mitigation in Library:

✅ RFC 6455 compliant handshake validation
✅ Strict header validation
✅ Proper Sec-WebSocket-Accept computation
✅ Version negotiation (only version 13 supported)
✅ Optional origin validation

User Recommendations:

// ❌ BAD - Don't skip origin validation in production
conn, _ := websocket.Upgrade(w, r, nil)
// ✅ GOOD - Validate origins
opts := &websocket.UpgradeOptions{
 CheckOrigin: func(r *http.Request) bool {
 origin := r.Header.Get("Origin")
 return origin == "https://yourdomain.com"
 },
}
conn, err := websocket.Upgrade(w, r, opts)
if err != nil {
 http.Error(w, "Forbidden", http.StatusForbidden)
 return
}

2. Denial of Service (DoS) Attacks

Risk: Long-lived connections can exhaust server resources.

Attack Vectors:

Connection exhaustion (opening thousands of connections)
Message flooding (sending excessive messages)
Large frame/event payloads (memory exhaustion)
Slow-read attacks (not consuming data)

Mitigation in Library:

✅ Configurable frame size limits
✅ Read/write timeouts
✅ Proper connection cleanup
✅ Hub-based broadcasting (efficient multi-client handling)

User Recommendations:

// ✅ Set connection limits
opts := &websocket.UpgradeOptions{
 ReadBufferSize: 4096,
 WriteBufferSize: 4096,
}
// ✅ Implement connection counting
var connCount atomic.Int32
http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
 if connCount.Load() >= 1000 {
 http.Error(w, "Too many connections", http.StatusServiceUnavailable)
 return
 }
 conn, _ := websocket.Upgrade(w, r, opts)
 connCount.Add(1)
 defer connCount.Add(-1)
 defer conn.Close()
 // Handle connection...
})
// ✅ Implement rate limiting per connection
limiter := rate.NewLimiter(100, 10) // 100 msg/s, burst 10
for {
 if !limiter.Allow() {
 conn.Close()
 break
 }
 msgType, data, err := conn.Read()
 if err != nil {
 break
 }
 // Process message...
}

3. Message Injection and XSS

Risk: Malicious messages can exploit client-side vulnerabilities.

Attack Vectors:

XSS via SSE event data
XSS via WebSocket messages
Malicious JSON payloads
Script injection in event streams

Mitigation:

✅ JSON parsing uses encoding/json/v2 (safe unmarshaling)
✅ Binary-safe message handling
🔄 User Responsibility: Sanitize data before sending to clients

User Best Practices:

// ❌ BAD - Don't send unsanitized user input
hub.BroadcastText(userInput)
// ✅ GOOD - Sanitize HTML content
import "html"
safeData := html.EscapeString(userInput)
hub.BroadcastText(safeData)
// ✅ BETTER - Use JSON (auto-escaped)
type Message struct {
 User string `json:"user"`
 Text string `json:"text"`
}
hub.BroadcastJSON(Message{
 User: username,
 Text: userMessage, // Auto-escaped in JSON
})
// ✅ WebSocket - validate message types
msgType, data, err := conn.Read()
if err != nil {
 return
}
if msgType != websocket.TextMessage && msgType != websocket.BinaryMessage {
 conn.Close() // Reject invalid types
 return
}

4. Authentication & Authorization

Risk: Unauthenticated access to real-time streams.

Attack Vectors:

Missing authentication on upgrade
Token theft via insecure connections
Session hijacking
Unauthorized subscription to private channels

Mitigation:

✅ Upgrade happens at HTTP layer (use standard HTTP authentication)
✅ Origin validation support
🔄 User Responsibility: Implement authentication before upgrade

User Best Practices:

// ✅ Authenticate BEFORE upgrading to WebSocket
http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
 // Validate JWT token from query param or header
 token := r.URL.Query().Get("token")
 user, err := validateToken(token)
 if err != nil {
 http.Error(w, "Unauthorized", http.StatusUnauthorized)
 return
 }
 // Now upgrade
 conn, err := websocket.Upgrade(w, r, &websocket.UpgradeOptions{
 CheckOrigin: func(r *http.Request) bool {
 return r.Header.Get("Origin") == "https://yourdomain.com"
 },
 })
 if err != nil {
 return
 }
 // Handle authenticated connection
 handleAuthenticatedConn(conn, user)
})
// ✅ SSE - use standard HTTP auth
http.HandleFunc("/events", func(w http.ResponseWriter, r *http.Request) {
 // Check Authorization header
 if !isAuthorized(r) {
 http.Error(w, "Forbidden", http.StatusForbidden)
 return
 }
 conn, _ := sse.Upgrade(w, r)
 defer conn.Close()
 // Send authorized events only
})

5. Frame Injection and Malformed Data

Risk: Malicious WebSocket frames can crash or compromise clients.

Attack Vectors:

Malformed WebSocket frames
Invalid UTF-8 in text frames
Incorrect masking
Reserved opcodes

Mitigation in Library:

✅ RFC 6455 compliant frame parsing
✅ UTF-8 validation for text frames
✅ Proper masking/unmasking
✅ Opcode validation
✅ Max frame size limits

User Best Practices:

// ✅ Validate received data
msgType, data, err := conn.Read()
if err != nil {
 log.Printf("Read error: %v", err)
 conn.Close()
 return
}
// Validate message type
if msgType != websocket.TextMessage {
 log.Printf("Unexpected message type: %d", msgType)
 conn.Close()
 return
}
// Parse and validate JSON
var msg Message
if err := json.Unmarshal(data, &msg); err != nil {
 log.Printf("Invalid JSON: %v", err)
 return // Ignore bad message, don't close
}

6. Resource Exhaustion via Hubs

Risk: Broadcasting to many clients can exhaust resources.

Attack Vectors:

Memory exhaustion from buffered channels
Goroutine leaks from unregistered clients
CPU exhaustion from excessive broadcasts

Mitigation in Library:

✅ Hub uses buffered channels
✅ Proper client cleanup on unregister
✅ Non-blocking broadcast operations
✅ Graceful hub shutdown

User Best Practices:

// ✅ Always unregister clients
http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
 conn, _ := websocket.Upgrade(w, r, nil)
 hub.Register(conn)
 defer hub.Unregister(conn) // Critical!
 for {
 _, data, err := conn.Read()
 if err != nil {
 break
 }
 hub.Broadcast(data)
 }
})
// ✅ Monitor hub health
go func() {
 ticker := time.NewTicker(10 * time.Second)
 for range ticker.C {
 count := hub.ClientCount()
 if count > 10000 {
 log.Printf("WARNING: High client count: %d", count)
 }
 }
}()

Security Best Practices for Users

Input Validation

Always validate messages from clients:

// Define message schema
type ChatMessage struct {
 Type string `json:"type"`
 Content string `json:"content"`
 UserID string `json:"user_id"`
}
// Validate all incoming messages
for {
 msgType, data, err := conn.Read()
 if err != nil {
 break
 }
 var msg ChatMessage
 if err := json.Unmarshal(data, &msg); err != nil {
 log.Printf("Invalid message format: %v", err)
 continue // Ignore invalid messages
 }
 // Validate fields
 if msg.Type == "" || msg.Content == "" {
 log.Printf("Missing required fields")
 continue
 }
 // Sanitize content before broadcasting
 msg.Content = html.EscapeString(msg.Content)
 // Process validated message
 handleMessage(msg)
}

Connection Rate Limiting

Protect against connection spam:

// Per-IP connection limits
var connLimiter = make(map[string]*rate.Limiter)
var limitMu sync.Mutex
func getConnLimiter(ip string) *rate.Limiter {
 limitMu.Lock()
 defer limitMu.Unlock()
 limiter, exists := connLimiter[ip]
 if !exists {
 limiter = rate.NewLimiter(1, 5) // 1 conn/sec, burst 5
 connLimiter[ip] = limiter
 }
 return limiter
}
http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
 ip := r.RemoteAddr
 if !getConnLimiter(ip).Allow() {
 http.Error(w, "Rate limit exceeded", http.StatusTooManyRequests)
 return
 }
 conn, _ := websocket.Upgrade(w, r, nil)
 // Handle connection...
})

Error Handling

Never leak sensitive information:

// ❌ BAD - Leaks internal details
conn, err := websocket.Upgrade(w, r, nil)
if err != nil {
 http.Error(w, err.Error(), 500) // Leaks implementation details!
}
// ✅ GOOD - Generic error messages
conn, err := websocket.Upgrade(w, r, nil)
if err != nil {
 log.Printf("WebSocket upgrade failed: %v", err) // Log internally
 http.Error(w, "Upgrade failed", http.StatusInternalServerError)
 return
}

HTTPS/WSS Enforcement

Always use secure connections in production:

// ✅ Require TLS for WebSocket connections
http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
 if r.TLS == nil {
 http.Error(w, "HTTPS required", http.StatusUpgradeRequired)
 return
 }
 conn, _ := websocket.Upgrade(w, r, &websocket.UpgradeOptions{
 CheckOrigin: func(r *http.Request) bool {
 origin := r.Header.Get("Origin")
 return strings.HasPrefix(origin, "https://")
 },
 })
 // Handle connection...
})
// ✅ Use WSS (WebSocket Secure) URLs on client
// wss://yourdomain.com/ws (NOT ws://)

Known Security Considerations

1. Connection Exhaustion

Status: Mitigated via configuration and best practices.

Risk Level: Medium

Description: Attackers can open thousands of connections to exhaust resources.

Mitigation:

Configurable timeouts
Frame size limits
Hub channel buffer limits
User responsibility to implement connection limits

2. Slow-Read/Write Attacks

Status: Mitigated via timeouts.

Risk Level: Medium

Description: Clients can deliberately read/write slowly to tie up resources.

Mitigation:

Buffered channels prevent blocking
🔄 User Responsibility: Set appropriate timeouts

3. Fragment Reassembly DoS

Status: Mitigated in library.

Risk Level: Low

Description: Excessive fragmented frames can exhaust memory.

Mitigation:

Max frame size enforced
RFC 6455 compliant implementation

4. Dependency Security

stream library has ZERO external dependencies:

✅ Pure stdlib implementation (SSE and WebSocket)
✅ No supply chain attacks
✅ No dependency vulnerabilities
✅ No transitive dependencies
✅ Smaller attack surface

Monitoring:

✅ Go stdlib security updates tracked
✅ No Dependabot needed (zero deps!)

Security Testing

Current Testing

✅ Unit tests with malicious frame data (314 tests)
✅ Malformed handshake tests
✅ Invalid UTF-8 validation tests
✅ Frame injection tests
✅ Race detector (go test -race)
✅ Static analysis (go vet)
✅ 34+ golangci-lint linters (security-focused)

Test Coverage

Overall: 84.3% (314 tests)
SSE: 92.3% coverage
WebSocket: 84.3% coverage

Planned for v1.0

🔄 Fuzzing with go-fuzz (frame parsing, handshakes)
🔄 Penetration testing of WebSocket endpoints
🔄 Load testing for DoS resilience
🔄 Memory profiling under attack scenarios

Security Disclosure History

No security vulnerabilities have been reported or fixed yet (project is in 0.x development).

When vulnerabilities are addressed, they will be listed here with:

CVE ID (if assigned)
Affected versions
Fixed in version
Severity (Critical/High/Medium/Low)
Credit to reporter

Security Contact

GitHub Security Advisory: https://github.com/coregx/stream/security/advisories/new
Public Issues (for non-sensitive bugs): https://github.com/coregx/stream/issues
Discussions: https://github.com/coregx/stream/discussions

Bug Bounty Program

stream library does not currently have a bug bounty program. We rely on responsible disclosure from the security community.

If you report a valid security vulnerability:

✅ Public credit in security advisory (if desired)
✅ Acknowledgment in CHANGELOG
✅ Our gratitude and recognition in README
✅ Priority review and quick fix

Thank you for helping keep stream secure! 🔒

Security is a journey, not a destination. We continuously improve our security posture with each release.

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Security: coregx/stream

Security

SECURITY.md

Security Policy

Supported Versions

Reporting a Vulnerability

How to Report

What to Include

Response Timeline

Security Considerations for Real-Time Communications

1. WebSocket Handshake Attacks

2. Denial of Service (DoS) Attacks

3. Message Injection and XSS

4. Authentication & Authorization

5. Frame Injection and Malformed Data

6. Resource Exhaustion via Hubs

Security Best Practices for Users

Input Validation

Connection Rate Limiting

Error Handling

HTTPS/WSS Enforcement

Known Security Considerations

1. Connection Exhaustion

2. Slow-Read/Write Attacks

3. Fragment Reassembly DoS

4. Dependency Security

Security Testing

Current Testing

Test Coverage

Planned for v1.0

Security Disclosure History

Security Contact

Bug Bounty Program

There aren't any published security advisories