From 54df169029f1c9f03afe9c830c9aa4ab0ad025d7 Mon Sep 17 00:00:00 2001
From: Erik Dubbelboer <erik@dubbelboer.com>
Date: Mon, 20 Apr 2020 18:30:10 +0200
Subject: [PATCH] Add fasthttpproxy.FasthttpHTTPDialer

---
 fasthttpproxy/http.go | 61 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 fasthttpproxy/http.go

diff --git a/fasthttpproxy/http.go b/fasthttpproxy/http.go
new file mode 100644
index 0000000000..2879408aaf
--- /dev/null
+++ b/fasthttpproxy/http.go
@@ -0,0 +1,61 @@
+package fasthttpproxy
+
+import (
+	"bufio"
+	"encoding/base64"
+	"fmt"
+	"net"
+	"strings"
+
+	"github.com/valyala/fasthttp"
+)
+
+// FasthttpHTTPDialer returns a fasthttp.DialFunc that dials using
+// the provided HTTP proxy.
+//
+// Example usage:
+//	c := &fasthttp.Client{
+//		Dial: fasthttpproxy.FasthttpHTTPDialer("username:password@localhost:9050"),
+//	}
+func FasthttpHTTPDialer(proxy string) fasthttp.DialFunc {
+	return func(addr string) (net.Conn, error) {
+		var auth string
+
+		if strings.Contains(proxy, "@") {
+			split := strings.Split(proxy, "@")
+			auth = base64.StdEncoding.EncodeToString([]byte(split[0]))
+			proxy = split[1]
+
+		}
+
+		conn, err := fasthttp.Dial(proxy)
+		if err != nil {
+			return nil, err
+		}
+
+		req := "CONNECT " + addr + " HTTP/1.1\r\n"
+		if auth != "" {
+			req += "Proxy-Authorization: Basic " + auth + "\r\n"
+		}
+		req += "\r\n"
+
+		if _, err := conn.Write([]byte(req)); err != nil {
+			return nil, err
+		}
+
+		res := fasthttp.AcquireResponse()
+		defer fasthttp.ReleaseResponse(res)
+
+		res.SkipBody = true
+
+		if err := res.Read(bufio.NewReader(conn)); err != nil {
+			conn.Close()
+			return nil, err
+		}
+		if res.Header.StatusCode() != 200 {
+			conn.Close()
+			return nil, fmt.Errorf("could not connect to proxy")
+		}
+		return conn, nil
+	}
+}