基于golang的http(s)与socks5代理服务器的代码实现

Golang可以轻松实现一个https代理，你需要执行以下步骤：

获取客户端请求: 使用Golang的net包接收客户端请求。转发请求: 使用Golang的http包将请求转发到服务端。获取服务端响应: 从服务端接收响应并将其返回给客户端。

以下是一个示例代码，实现了一个https代理：

package main
import (
	"bufio"
	"io"
	"net"
	"net/http"
	"net/http/httputil"
)
func handleHttps(w http.ResponseWriter, r *http.Request) {
	dest_conn, err := net.DialTimeout("tcp", r.Host, 10*time.Second)
	if err != nil {
		http.Error(w, err.Error(), http.StatusServiceUnavailable)
		return
	}
	w.WriteHeader(http.StatusOK)
	hijacker, ok := w.(http.Hijacker)
	if !ok {
		http.Error(w, "Hijacking not supported", http.StatusInternalServerError)
		return
	}
	client_conn, _, err := hijacker.Hijack()
	if err != nil {
		http.Error(w, err.Error(), http.StatusServiceUnavailable)
	}
	go transfer(dest_conn, client_conn)
	go transfer(client_conn, dest_conn)
}
func transfer(destination io.WriteCloser, source io.ReadCloser) {
	defer destination.Close()
	defer source.Close()
	io.Copy(destination, source)
}
func handleHTTP(w http.ResponseWriter, req *http.Request) {
	resp, err := http.DefaultTransport.RoundTrip(req)
	if err != nil {
		http.Error(w, err.Error(), http.StatusServiceUnavailable)
		return
	}
	defer resp.Body.Close()
	copyHeader(w.Header(), resp.Header)
	w.WriteHeader(resp.StatusCode)
	io.Copy(w, resp.Body)
}
func copyHeader(dst, src http.Header) {
	for k, vv := range src {
		for _, v := range vv {
			dst.Add(k, v)
		}
	}
}

SOCKS代理

Socks5协议是一种灵活的代理协议,主要用于实现代理服务器的功能，允许客户端通过代理服务器与其他网络资源进行通信。Socks5协议比Socks4协议更先进，具有更多的特性，如它支持用户名/密码验证寻求web网页代理速度要快寻求web网页代理速度要快，还支持TCP和UDP协议.下面实现的是Socks5代理协议

package main
import (
    "bufio"
    "fmt"
    "net"
    "os"
)
func main() {
    l, err := net.Listen("tcp", ":1080")
    if err != nil {
        fmt.Println(err)
        os.Exit(1)
    }
    defer l.Close()
    for {
        client, err := l.Accept()
        if err != nil {
            fmt.Println(err)
            continue
        }
        go handleClientRequest(client)
    }
}
func handleClientRequest(client net.Conn) {
    if client == nil {
        return
    }
    defer client.Close()
    var b [1024]byte
    n, err := client.Read(b[:])
    if err != nil {
        fmt.Println(err)
        return
    }
    var host, port string
    switch b[3] {
    case 0x01: // IPv4
        host = net.IPv4(b[4], b[5], b[6], b[7]).String()
        port = fmt.Sprintf("%d", b[8]<<8|b[9])
    case 0x03: // Domain name
        host = string(b[5 : n-2])
        port = fmt.Sprintf("%d", b[n-2]<<8|b[n-1])
    case 0x04: // IPv6
        host = net.IP{b[4], b[5], b[6], b[7], b[8], b[9], b[10], b[11], b[12], b[13], b[14], b[15], b[16], b[17], b[18], b[19]}.String()
        port = fmt.Sprintf("%d", b[20]<<8|b[21])
    }
    server, err := net.Dial("tcp", host+":"+port)
    if err != nil {
        fmt.Println(err)
        return
    }
    defer server.Close()
    client.Write([]byte{0x05, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x08, 0x43})
    go func() {
        _, err := io.Copy(server, client)
        if err != nil {
            fmt.Println("io.Copy error:", err)
        }
    }()
    _, err = io.Copy(client, server)
    if err != nil {
        fmt.Println("io.Copy error:", err)
    }
}