https://github.com/fxpool/fxeccsocket
A Go library providing encrypted TCP connections using Elliptic Curve Cryptography (ECC) for key exchange and ChaCha20-Poly1305 for symmetric encryption.
https://github.com/fxpool/fxeccsocket
Last synced: 9 months ago
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A Go library providing encrypted TCP connections using Elliptic Curve Cryptography (ECC) for key exchange and ChaCha20-Poly1305 for symmetric encryption.
- Host: GitHub
- URL: https://github.com/fxpool/fxeccsocket
- Owner: FxPool
- License: mit
- Created: 2025-09-25T13:13:09.000Z (9 months ago)
- Default Branch: main
- Last Pushed: 2025-10-03T10:07:16.000Z (9 months ago)
- Last Synced: 2025-10-03T11:41:18.959Z (9 months ago)
- Language: Go
- Size: 61.5 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# ECC Socket - Secure Communication Library using Elliptic Curve Cryptography
[](https://golang.org)
[](LICENSE)
A secure network communication library for Go that provides end-to-end encrypted communication using Elliptic Curve Cryptography (ECC) with advanced traffic obfuscation capabilities.
## Features
- 🔒 **End-to-End Encryption**: ECDH key exchange with ChaCha20-Poly1305 encryption
- 🎭 **Traffic Obfuscation**: Multiple obfuscation modes to hide traffic patterns
- 🚀 **High Performance**: Modern cryptographic algorithms with low latency
- 🔑 **Flexible Key Management**: Support for both static and ephemeral keys (forward secrecy)
- 📜 **Standards Compliant**: PEM format for key storage
- 🛡️ **Security Hardened**: Replay protection, integrity verification
- 🔧 **Easy to Use**: net-like API design for easy integration
## Installation
```bash
go get github.com/fxpool/fxeccsocket
```
## Quick Start
## Generating Key Pairs
```go
package main
import (
"fmt"
"github.com/yourusername/fxeccsocket"
)
func main() {
// Generate new ECC key pair
privKey, err := fxeccsocket.GenerateKey(nil)
if err != nil {
panic(err)
}
// Encode private key to PEM format
privPEM, err := fxeccsocket.EncodePrivateKey(privKey)
if err != nil {
panic(err)
}
// Encode public key to PEM format
pubPEM, err := fxeccsocket.EncodePublicKey(&privKey.PublicKey)
if err != nil {
panic(err)
}
fmt.Println("Private Key:\n", privPEM)
fmt.Println("Public Key:\n", pubPEM)
}
```
## Basic Example (No Obfuscation)
```go
package main
import (
"fmt"
"github.com/FxPool/fxeccsocket"
"io"
"log"
"net"
"time"
)
// Server example
func startServer() {
listener, err := fxeccsocket.Listen("tcp", ":8080", nil)
if err != nil {
log.Fatal("Server listen error:", err)
}
defer listener.Close()
fmt.Println("ECC Server listening on :8080")
for {
conn, err := listener.Accept()
if err != nil {
log.Println("Accept error:", err)
continue
}
go handleServerConnection(conn)
}
}
func handleServerConnection(conn net.Conn) {
defer conn.Close()
fmt.Printf("New connection from %s\n", conn.RemoteAddr())
buffer := make([]byte, 1024)
for {
n, err := conn.Read(buffer)
if err != nil {
if err != io.EOF {
log.Println("server Read error:", err)
}
break
}
message := string(buffer[:n])
fmt.Printf("Received: %s", message)
response := fmt.Sprintf("Server response: %s", message)
_, err = conn.Write([]byte(response))
if err != nil {
log.Println("Write error:", err)
break
}
}
}
// Client example
func startClient() {
time.Sleep(100 * time.Millisecond) // Wait for server to start
conn, err := fxeccsocket.Dial("tcp", "localhost:8080", nil)
if err != nil {
log.Fatal("Client dial error:", err)
}
defer conn.Close()
fmt.Printf("Connected to %s\n", conn.RemoteAddr())
// Send multiple messages for testing
messages := []string{
"Hello, ECC Socket 1!\n",
"This is message 2\n",
"Final message 3\n",
}
for _, msg := range messages {
fmt.Printf("Sending: %s", msg)
_, err = conn.Write([]byte(msg))
if err != nil {
log.Fatal("Write error:", err)
}
buffer := make([]byte, 1024)
n, err := conn.Read(buffer)
if err != nil {
log.Fatal("client Read error:", err)
}
fmt.Printf("Server reply: %s", string(buffer[:n]))
time.Sleep(100 * time.Millisecond)
}
}
func main() {
// Start the server
go startServer()
time.Sleep(1 * time.Second)
// Start the client
startClient()
}
```
## Advanced Example (With Traffic Obfuscation)
```go
package main
import (
"fmt"
"github.com/FxPool/fxeccsocket"
"log"
"time"
)
func main() {
// Obfuscation configuration for both client and server
obfuscationConfig := &fxeccsocket.ObfuscationConfig{
Enabled: true,
Mode: fxeccsocket.ObfuscationHTTPS,
Domain: "api.cloudflare.com",
MinDelayMs: 5,
MaxDelayMs: 50,
MinPacketSize: 128,
MaxPacketSize: 1460,
}
serverConfig := &fxeccsocket.Config{
Curve: elliptic.P256(),
Obfuscation: obfuscationConfig,
}
clientConfig := &fxeccsocket.Config{
Curve: elliptic.P256(),
Obfuscation: obfuscationConfig,
}
// Start obfuscated server
go func() {
listener, err := fxeccsocket.Listen("tcp", ":8081", serverConfig)
if err != nil {
log.Fatal("Server listen error:", err)
}
defer listener.Close()
fmt.Println("Obfuscated ECC Server listening on :8081")
conn, err := listener.Accept()
if err != nil {
log.Fatal("Accept error:", err)
}
defer conn.Close()
// Handle connection...
}()
time.Sleep(1 * time.Second)
// Connect with obfuscated client
conn, err := fxeccsocket.Dial("tcp", "localhost:8081", clientConfig)
if err != nil {
log.Fatal("Client dial error:", err)
}
defer conn.Close()
fmt.Println("Connected with traffic obfuscation enabled")
}
```
## Traffic Obfuscation
### Obfuscation Modes
The library provides multiple traffic obfuscation modes to hide encryption patterns:
1. HTTP Obfuscation
- Masks traffic as standard HTTP requests/responses
- Uses proper HTTP headers and chunked encoding
- Simulates real web traffic patterns
2. HTTPS Obfuscation
- Similar to HTTP but with TLS-like characteristics
- More convincing for environments expecting encrypted web traffic
- Uses realistic domain names and user agents
3. Random Padding Obfuscation
- Adds random padding to disrupt packet size analysis
- Randomizes packet timing with configurable delays
- Makes traffic analysis more difficult
## Obfuscation Configuration
```go
type ObfuscationConfig struct {
Enabled bool // Enable/disable obfuscation
Mode ObfuscationMode // Obfuscation mode (HTTP/HTTPS/Random)
Domain string // Domain for HTTP/HTTPS obfuscation
MinDelayMs int // Minimum delay between packets (ms)
MaxDelayMs int // Maximum delay between packets (ms)
MinPacketSize int // Minimum packet size for padding
MaxPacketSize int // Maximum packet size for padding
}
```
## Usage Notes
- Symmetric Configuration: Client and server must use identical obfuscation settings
- Performance: Obfuscation adds minimal overhead (5-15% depending on mode)
- Stealth: Effectively hides traffic from deep packet inspection (DPI) systems
# API Documentation
## Types
## ECCConn
## Encrypted connection type implementing net.Conn interface.
```go
type ECCConn struct {
// unexported fields
}
```
### Methods:
- Read([]byte) (int, error) - Read and decrypt data
- Write([]byte) (int, error) - Encrypt and write data
- Close() error - Close the connection
- GetPublicKey() *ecdsa.PublicKey - Get local public key
- Standard net.Conn methods: LocalAddr(), RemoteAddr(), SetDeadline(), etc.
### ECCListener
### Encrypted connection listener.
```go
type ECCListener struct {
// unexported fields
}
```
### Methods:
- `Accept() (net.Conn, error)` - Accept new connection
- `Close() error` - Close listener
- `Addr() net.Addr` - Get listen address
### Config
### Configuration parameters structure.
```go
type Config struct {
Curve elliptic.Curve // Elliptic curve (default P-256)
PrivateKey *ecdsa.PrivateKey // Private key (optional)
PublicKey *ecdsa.PublicKey // Public key (optional)
UseEphemeralKey bool // Use ephemeral keys (forward secrecy)
Obfuscation *ObfuscationConfig // Traffic obfuscation settings
}
```
#### ObfuscationConfig
#### Traffic obfuscation configuration.
```go
type ObfuscationConfig struct {
Enabled bool // Enable traffic obfuscation
Mode ObfuscationMode // Obfuscation mode
Domain string // Domain for HTTP/HTTPS obfuscation
MinDelayMs int // Minimum packet delay (milliseconds)
MaxDelayMs int // Maximum packet delay (milliseconds)
MinPacketSize int // Minimum packet size
MaxPacketSize int // Maximum packet size
}
```
#### Obfuscation Modes
```go
const (
ObfuscationNone ObfuscationMode = iota // No obfuscation
ObfuscationHTTP // HTTP traffic obfuscation
ObfuscationHTTPS // HTTPS traffic obfuscation
ObfuscationRandom // Random padding obfuscation
)
```
### Functions
### Key Management
```go
func GenerateKey(curve elliptic.Curve) (*ecdsa.PrivateKey, error)
func EncodePrivateKey(key *ecdsa.PrivateKey) (string, error)
func DecodePrivateKey(pemData string) (*ecdsa.PrivateKey, error)
func EncodePublicKey(key *ecdsa.PublicKey) (string, error)
func DecodePublicKey(pemData string) (*ecdsa.PublicKey, error)
```
### Connection Management
```go
func Dial(network, address string, config *Config) (*ECCConn, error)
func Listen(network, address string, config *Config) (*ECCListener, error)
func NewConn(conn net.Conn, config *Config, isClient bool) (*ECCConn, error)
```
## Protocol Details
## Handshake Protocol
1. Key Exchange: ECDH Elliptic Curve Diffie-Hellman key exchange
2. Key Derivation: HKDF for symmetric key derivation from shared secret
3. Bidirectional Authentication: Different key contexts for client and server
4. Traffic Obfuscation: Optional masking of encrypted traffic
### Message Format
### Public Key Message
```
+------+--------+------------+
| 0x01 | Length | Public Key |
+------+--------+------------+
| 1B | 2B | Variable |
+------+--------+------------+
```
### Encrypted Data Message
```
+------+-----------+----------------+
| 0x02 | Length | Encrypted Data |
+------+-----------+----------------+
| 1B | 4B | Variable |
+------+-----------+----------------+
```
## Obfuscated Message Format
### HTTP Obfuscation Format
```text
HTTP Headers + Chunked Encoding + Encrypted Data
```
## Random Padding Format
```text
Encrypted Data + Random Padding (variable length)
```
## Key Derivation
```
client_send_key = HKDF(shared_secret, salt, "client_key")
server_send_key = HKDF(shared_secret, salt, "server_key")
```
### Security Considerations
### Recommended Configuration
```go
// For optimal security, recommended to use:
config := &fxeccsocket.Config{
Curve: elliptic.P256(), // Or more secure curves
UseEphemeralKey: true, // Enable forward secrecy
Obfuscation: &fxeccsocket.ObfuscationConfig{
Enabled: true,
Mode: fxeccsocket.ObfuscationHTTPS,
Domain: "cdn.google.com",
MinDelayMs: 10,
MaxDelayMs: 100,
},
}
```
### Security Features
- Forward Secrecy: When UseEphemeralKey is enabled, each connection uses different ephemeral keys
- Replay Protection: Incrementing counter-based nonce prevents replay attacks
- Integrity Verification: Poly1305 authentication tags ensure data integrity
- Key Separation: Different encryption keys for client and server directions
- Traffic Obfuscation: Hides encryption patterns from network analysis
### Obfuscation Security Benefits
- Pattern Hiding: Disrupts packet size and timing analysis
- Protocol Mimicry: Appears as legitimate web traffic to DPI systems
- Plausible Deniability: Traffic resembles common internet protocols
### Performance Considerations
- Uses ChaCha20-Poly1305 instead of AES-GCM for better performance on devices without AES hardware acceleration
- Single connection throughput can reach Gbps levels
- Low memory footprint, suitable for high-concurrency scenarios
- Low memory footprint, suitable for high-concurrency scenarios
### Obfuscation Performance Impact
- HTTP/HTTPS Mode: ~10-15% overhead due to header processing
- Random Padding: ~5-10% overhead depending on padding size
- Network Delays: Configurable delays add latency but improve stealth
### Limitations
- Maximum message size: 64KB (configurable via maxMessageSize constant)
- Currently only supports TCP protocol
- Requires Go 1.16+ version
- Obfuscation requires symmetric client/server configuration
### Troubleshooting
### Common Errors
1. "unexpected message type"
- - Check client and server version compatibility
- - Verify network connection isn't being interfered with
- - Check network connection isn't being interfered with
2. "public key too large"
- - Check if the elliptic curve used is reasonable
- - Verify public key serialization is correct
3. Authentication failures
- - Check system clock synchronization
- - Verify keys are loaded correctly
4. Obfuscation mismatches
- - Ensure client and server use identical ObfuscationConfig
- - Verify Enabled flag and Mode are the same on both ends
### Debug Mode
Add verbose logging to debug handshake process.
### Benchmarks
Basic performance metrics (on Intel i7-8700K):
```
Encryption throughput: ~800 Mbps
Handshake time: ~2.5 ms
Memory per connection: ~4 KB
Obfuscation overhead: 5-15% (depending on mode)
```
### Examples Directory
- Check the `examples/` directory for additional usage examples
- Check the `test/` directory for additional usage examples
### Contributing
We welcome contributions! Please see our Contributing Guide for details.
1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Push to the branch
5. Create a Pull Request
### Development Setup
```base
git clone https://github.com/fxpool/fxeccsocket.git
cd fxeccsocket
go test ./...
```
### Running Tests
```base
go test -v -race ./...
```
### License
This project is open source under the MIT License - see the LICENSE file for details.
### Acknowledgments
- Uses Go standard library cryptographic primitives
- Designed based on modern cryptographic best practices
- Traffic obfuscation techniques inspired by modern anti-censorship tools
- Thanks to all contributors
### Support
- If you encounter issues or have questions:
- Check existing issues
- Create a new issue with detailed description
- Contact maintainers
### Related Projects
- libsodium - Portable cryptography library
- Noise Protocol - Framework for crypto protocols
- WireGuard - Modern VPN protocol
- obfs4 - Pluggable transport for Tor
### References
- Elliptic Curve Cryptography
- ChaCha20 and Poly1305
- HKDF (HMAC-based Key Derivation Function)
- Traffic Analysis Resistance
- Pluggable Transports