Do not limit hash format only to md5

http/api.go

@@ -23,19 +23,6 @@ const UUID_ANY = "^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$
 var regexUuidAny = regexp.MustCompile(UUID_ANY)
 
 func init() {
-	govalidator.AddCustomRule("md5", func(field string, rule string, message string, value interface{}) error {
-		val := []byte(value.(string))
-		if ok, _ := regexp.Match(`^[a-f0-9]{32}$`, val); !ok {
-			if message == "" {
-				message = fmt.Sprintf("The %s field must be a valid md5 hash", field)
-			}
-
-			return errors.New(message)
-		}
-
-		return nil
-	})
-
 	govalidator.AddCustomRule("skinUploadingNotAvailable", func(field string, rule string, message string, value interface{}) error {
 		if message == "" {
 			message = "Skin uploading is temporary unavailable"
@@ -174,7 +161,7 @@ func validatePostSkinRequest(request *http.Request) map[string][]string {
 		"skinId":     {"required", "numeric", "min:1"},
 		"url":        {"url"},
 		"file:skin":  {"ext:png", "size:24576", "mime:image/png"},
-		"hash":       {"md5"},
+		"hash":       {},
 		"is1_8":      {"bool"},
 		"isSlim":     {"bool"},
 	}

http/api_test.go

@@ -268,7 +268,6 @@ func TestConfig_PostSkin_RequiredFields(t *testing.T) {
 	config, mocks := setupMocks(ctrl)
 
 	form := url.Values{
-		"hash":           {"this is not md5"},
 		"mojangTextures": {"someBase64EncodedString"},
 	}
 
@@ -307,9 +306,6 @@ func TestConfig_PostSkin_RequiredFields(t *testing.T) {
 				"The uuid field is required",
 				"The uuid field must contain valid UUID"
 			],
-			"hash": [
-				"The hash field must be a valid md5 hash"
-			],
 			"url": [
 				"One of url or skin should be provided, but not both"
 			],