/
main.go
210 lines (180 loc) · 4.77 KB
/
main.go
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package server
import (
"bytes"
"crypto/rand"
"crypto/rsa"
"crypto/x509/pkix"
"encoding/pem"
"io"
"log"
"math/big"
"net"
"sync"
"time"
"crypto/tls"
"crypto/x509"
yamux "github.com/hashicorp/yamux"
)
var tunnelAddress string
var socksAddress string
func New(tunnelAddress string, socksAddress string) {
server, err := createTunnelServer(tunnelAddress)
if err != nil {
log.Println(err)
return
}
defer server.Close()
for {
log.Println("Waiting for connections...")
conn, err := server.Accept()
if err != nil {
log.Println(err)
return
}
handleConnection(conn, socksAddress)
}
}
func createTunnelServer(host string) (server net.Listener, err error) {
certPem, keyPem, err := certsetup()
cer, err := tls.X509KeyPair(certPem.Bytes(), keyPem.Bytes())
if err != nil {
log.Println(err)
return
}
config := &tls.Config{Certificates: []tls.Certificate{cer}}
server, err = tls.Listen("tcp", host, config)
if err != nil {
log.Println(err)
return
}
return
}
func certsetup() (certPEM *bytes.Buffer, certPrivKeyPEM *bytes.Buffer, err error) {
// set up our CA certificate
// TODO: Randomize this :D
log.Println("Creating Certificates...")
ca := &x509.Certificate{
SerialNumber: big.NewInt(2019),
Subject: pkix.Name{
Organization: []string{"Company, INC."},
Country: []string{"US"},
Province: []string{""},
Locality: []string{"San Francisco"},
StreetAddress: []string{"Golden Gate Bridge"},
PostalCode: []string{"94016"},
},
NotBefore: time.Now(),
NotAfter: time.Now().AddDate(10, 0, 0),
IsCA: true,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
KeyUsage: x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
BasicConstraintsValid: true,
}
// create our private and public key
caPrivKey, err := rsa.GenerateKey(rand.Reader, 4096)
if err != nil {
return nil, nil, err
}
// create the CA
caBytes, err := x509.CreateCertificate(rand.Reader, ca, ca, &caPrivKey.PublicKey, caPrivKey)
if err != nil {
return nil, nil, err
}
// pem encode
caPEM := new(bytes.Buffer)
pem.Encode(caPEM, &pem.Block{
Type: "CERTIFICATE",
Bytes: caBytes,
})
caPrivKeyPEM := new(bytes.Buffer)
pem.Encode(caPrivKeyPEM, &pem.Block{
Type: "RSA PRIVATE KEY",
Bytes: x509.MarshalPKCS1PrivateKey(caPrivKey),
})
// set up our server certificate
// TODO: Randomize this :D
cert := &x509.Certificate{
SerialNumber: big.NewInt(2019),
Subject: pkix.Name{
Organization: []string{"Company, INC."},
Country: []string{"US"},
Province: []string{""},
Locality: []string{"San Francisco"},
StreetAddress: []string{"Golden Gate Bridge"},
PostalCode: []string{"94016"},
},
IPAddresses: []net.IP{net.IPv4(127, 0, 0, 1), net.IPv6loopback},
NotBefore: time.Now(),
NotAfter: time.Now().AddDate(10, 0, 0),
SubjectKeyId: []byte{1, 2, 3, 4, 6},
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
KeyUsage: x509.KeyUsageDigitalSignature,
}
certPrivKey, err := rsa.GenerateKey(rand.Reader, 4096)
if err != nil {
return nil, nil, err
}
certBytes, err := x509.CreateCertificate(rand.Reader, cert, ca, &certPrivKey.PublicKey, caPrivKey)
if err != nil {
return nil, nil, err
}
certPEM = new(bytes.Buffer)
pem.Encode(certPEM, &pem.Block{
Type: "CERTIFICATE",
Bytes: certBytes,
})
certPrivKeyPEM = new(bytes.Buffer)
pem.Encode(certPrivKeyPEM, &pem.Block{
Type: "RSA PRIVATE KEY",
Bytes: x509.MarshalPKCS1PrivateKey(certPrivKey),
})
return
}
func handleConnection(conn net.Conn, socksHost string) {
// Wrap connection in yamux
session, err := yamux.Server(conn, nil)
if err != nil {
log.Println("[!] Error initializing yamux tunnel")
return
}
defer conn.Close()
defer session.Close()
// Listen on SOCKSv5 server port
socksServer, err := net.Listen("tcp", socksHost)
if err != nil {
log.Println("[!] Error listening for SOCKSv5 clients: " + err.Error())
return
}
defer socksServer.Close()
// Accept on socksv5 port; open new stream and start new goroutine to proxy
log.Println("[+] Waiting for SOCKS clients on " + socksHost)
for {
client, err := socksServer.Accept()
if err != nil {
log.Println("[!] Error accepting connection from SOCKS client: " + err.Error())
continue
}
stream, err := session.Open()
if err != nil {
log.Println("[+] Error opening new stream in tunnel: " + err.Error())
return
}
go proxy(client, stream)
}
return
}
func proxy(c1 net.Conn, c2 net.Conn) {
var wg sync.WaitGroup
intProxy := func(a net.Conn, b net.Conn) {
defer a.Close()
defer b.Close()
io.Copy(a, b)
wg.Done()
}
go intProxy(c1, c2)
wg.Add(1)
go intProxy(c2, c1)
wg.Add(1)
wg.Wait()
return
}