Fix slice bounds when getting key of address (fixes #2706)

caddyhttp/httpserver/plugin.go

@@ -490,11 +490,10 @@ func (a Address) Key() string {
 	if a.Host != "" {
 		res += a.Host
 	}
-	if a.Port != "" {
-		if strings.HasPrefix(a.Original[len(res):], ":"+a.Port) {
-			// insert port only if the original has its own explicit port
-			res += ":" + a.Port
-		}
+	// insert port only if the original has its own explicit port
+	if a.Port != "" && len(a.Original) >= len(res) &&
+		strings.HasPrefix(a.Original[len(res):], ":"+a.Port) {
+		res += ":" + a.Port
 	}
 	if a.Path != "" {
 		res += a.Path
@@ -553,10 +552,12 @@ func standardizeAddress(str string) (Address, error) {
 
 	// standardize http and https ports to their respective port numbers
 	// (this behavior changed in Go 1.12.8)
-	if port == httpPort {
-		u.Scheme = "http"
-	} else if port == httpsPort {
-		u.Scheme = "https"
+	if u.Scheme == "" {
+		if port == httpPort {
+			u.Scheme = "http"
+		} else if port == httpsPort {
+			u.Scheme = "https"
+		}
 	}
 
 	return Address{Original: input, Scheme: u.Scheme, Host: host, Port: port, Path: u.Path}, nil

caddyhttp/httpserver/plugin_test.go

@@ -43,8 +43,8 @@ func TestStandardizeAddress(t *testing.T) {
 		{`:`, "", "", "", "", false},
 		{`localhost:http`, "http", "localhost", "80", "", false},
 		{`localhost:https`, "https", "localhost", "443", "", false},
-		{`:http`, "http", "", "80", "", false},
-		{`:https`, "https", "", "443", "", false},
+		{`:http`, "http", "", "80", "", false},                          // as of Go 1.12.8, service name in port is no longer supported
+		{`:https`, "https", "", "443", "", false},                       // as of Go 1.12.8, service name in port is no longer supported
 		{`http://localhost:https`, "", "", "", "", true},                // conflict
 		{`http://localhost:http`, "http", "localhost", "80", "", false}, // repeated scheme -- test adjusted for Go 1.12.8 (expect no error)
 		{`http://localhost:443`, "", "", "", "", true},                  // not conventional
@@ -212,6 +212,10 @@ func TestKeyNormalization(t *testing.T) {
 		orig string
 		res  string
 	}{
+		{
+			orig: "http://host:1234/path",
+			res:  "http://host:1234/path",
+		},
 		{
 			orig: "HTTP://A/ABCDEF",
 			res:  "http://a/ABCDEF",
@@ -221,8 +225,20 @@ func TestKeyNormalization(t *testing.T) {
 			res:  "a/ABCDEF",
 		},
 		{
-			orig: "A:2015/Port",
-			res:  "a:2015/Port",
+			orig: "A:2015/Path",
+			res:  "a:2015/Path",
+		},
+		{
+			orig: ":80",
+			res:  "http://",
+		},
+		{
+			orig: ":443",
+			res:  "https://",
+		},
+		{
+			orig: ":1234",
+			res:  ":1234",
 		},
 	}
 	for _, item := range caseSensitiveData {