fix basicAuth function not in go1.3.3

Docker-DCO-1.1-Signed-off-by: Jessie Frazelle <jess@docker.com> (github: jfrazelle)

Docker-DCO-1.1-Signed-off-by: Jessie Frazelle <princess@docker.com> (github: jfrazelle)

requestdecorator/requestdecorator_test.go

@@ -1,11 +1,45 @@
 package requestdecorator
 
 import (
+	"encoding/base64"
 	"net/http"
 	"strings"
 	"testing"
 )
 
+// The following 2 functions are here for 1.3.3 support
+// After we drop 1.3.3 support we can use the functions supported
+// in go v1.4.0 +
+// BasicAuth returns the username and password provided in the request's
+// Authorization header, if the request uses HTTP Basic Authentication.
+// See RFC 2617, Section 2.
+func basicAuth(r *http.Request) (username, password string, ok bool) {
+	auth := r.Header.Get("Authorization")
+	if auth == "" {
+		return
+	}
+	return parseBasicAuth(auth)
+}
+
+// parseBasicAuth parses an HTTP Basic Authentication string.
+// "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==" returns ("Aladdin", "open sesame", true).
+func parseBasicAuth(auth string) (username, password string, ok bool) {
+	const prefix = "Basic "
+	if !strings.HasPrefix(auth, 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 TestUAVersionInfo(t *testing.T) {
 	uavi := NewUAVersionInfo("foo", "bar")
 	if !uavi.isValid() {
@@ -113,7 +147,7 @@ func TestAuthDecorator(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	username, password, ok := reqDecorated.BasicAuth()
+	username, password, ok := basicAuth(reqDecorated)
 	if !ok {
 		t.Fatalf("Cannot retrieve basic auth info from request")
 	}
@@ -155,7 +189,7 @@ func TestRequestFactory(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	username, password, ok := req.BasicAuth()
+	username, password, ok := basicAuth(req)
 	if !ok {
 		t.Fatalf("Cannot retrieve basic auth info from request")
 	}
@@ -186,7 +220,7 @@ func TestRequestFactoryNewRequestWithDecorators(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	username, password, ok := req.BasicAuth()
+	username, password, ok := basicAuth(req)
 	if !ok {
 		t.Fatalf("Cannot retrieve basic auth info from request")
 	}