optimize some code (#3801)

pkg/util/http/http.go

@@ -0,0 +1,102 @@
+// Copyright 2023 The frp Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package http
+
+import (
+	"encoding/base64"
+	"net"
+	"net/http"
+	"strings"
+)
+
+func OkResponse() *http.Response {
+	header := make(http.Header)
+
+	res := &http.Response{
+		Status:     "OK",
+		StatusCode: 200,
+		Proto:      "HTTP/1.1",
+		ProtoMajor: 1,
+		ProtoMinor: 1,
+		Header:     header,
+	}
+	return res
+}
+
+func ProxyUnauthorizedResponse() *http.Response {
+	header := make(http.Header)
+	header.Set("Proxy-Authenticate", `Basic realm="Restricted"`)
+	res := &http.Response{
+		Status:     "Proxy Authentication Required",
+		StatusCode: 407,
+		Proto:      "HTTP/1.1",
+		ProtoMajor: 1,
+		ProtoMinor: 1,
+		Header:     header,
+	}
+	return res
+}
+
+// canonicalHost strips port from host if present and returns the canonicalized
+// host name.
+func CanonicalHost(host string) (string, error) {
+	var err error
+	host = strings.ToLower(host)
+	if hasPort(host) {
+		host, _, err = net.SplitHostPort(host)
+		if err != nil {
+			return "", err
+		}
+	}
+	// Strip trailing dot from fully qualified domain names.
+	host = strings.TrimSuffix(host, ".")
+	return host, nil
+}
+
+// hasPort reports whether host contains a port number. host may be a host
+// name, an IPv4 or an IPv6 address.
+func hasPort(host string) bool {
+	colons := strings.Count(host, ":")
+	if colons == 0 {
+		return false
+	}
+	if colons == 1 {
+		return true
+	}
+	return host[0] == '[' && strings.Contains(host, "]:")
+}
+
+func ParseBasicAuth(auth string) (username, password string, ok bool) {
+	const prefix = "Basic "
+	// Case insensitive prefix match. See Issue 22736.
+	if len(auth) < len(prefix) || !strings.EqualFold(auth[:len(prefix)], prefix) {
+		return
+	}
+	c, err := base64.StdEncoding.DecodeString(auth[len(prefix):])
+	if err != nil {
+		return
+	}
+	cs := string(c)
+	s := strings.IndexByte(cs, ':')
+	if s < 0 {
+		return
+	}
+	return cs[:s], cs[s+1:], true
+}
+
+func BasicAuth(username, passwd string) string {
+	auth := username + ":" + passwd
+	return "Basic " + base64.StdEncoding.EncodeToString([]byte(auth))
+}