[GITEA] add option for banning dots in usernames

Refs: https://codeberg.org/forgejo/forgejo/pulls/676

Author:    Panagiotis "Ivory" Vasilopoulos <git@n0toose.net>
Date:      Mon Jun 12 13:57:01 2023 +0200

Co-authored-by: Gusted <postmaster@gusted.xyz>
(cherry picked from commit fabdda5c6e)
(cherry picked from commit d2c7f45621)
(cherry picked from commit dfdbaba3d6)
(cherry picked from commit a3cda092b8)
(cherry picked from commit f0fdb5905c)
(cherry picked from commit 9697e48c1f)
(cherry picked from commit 46e31009a8)

custom/conf/app.example.ini

@@ -806,6 +806,11 @@ LEVEL = Info
 ;; Every new user will have restricted permissions depending on this setting
 ;DEFAULT_USER_IS_RESTRICTED = false
 ;;
+;; Users will be able to use dots when choosing their username. Disabling this is
+;; helpful if your usersare having issues with e.g. RSS feeds or advanced third-party
+;; extensions that use strange regex patterns.
+; ALLOW_DOTS_IN_USERNAMES = true
+;;
 ;; Either "public", "limited" or "private", default is "public"
 ;; Limited is for users visible only to signed users
 ;; Private is for users visible only to members of their organizations

modules/setting/service.go

@@ -67,6 +67,7 @@ var Service = struct {
 	DefaultKeepEmailPrivate                 bool
 	DefaultAllowCreateOrganization          bool
 	DefaultUserIsRestricted                 bool
+	AllowDotsInUsernames                    bool
 	EnableTimetracking                      bool
 	DefaultEnableTimetracking               bool
 	DefaultEnableDependencies               bool
@@ -178,6 +179,7 @@ func loadServiceFrom(rootCfg ConfigProvider) {
 	Service.DefaultKeepEmailPrivate = sec.Key("DEFAULT_KEEP_EMAIL_PRIVATE").MustBool()
 	Service.DefaultAllowCreateOrganization = sec.Key("DEFAULT_ALLOW_CREATE_ORGANIZATION").MustBool(true)
 	Service.DefaultUserIsRestricted = sec.Key("DEFAULT_USER_IS_RESTRICTED").MustBool(false)
+	Service.AllowDotsInUsernames = sec.Key("ALLOW_DOTS_IN_USERNAMES").MustBool(true)
 	Service.EnableTimetracking = sec.Key("ENABLE_TIMETRACKING").MustBool(true)
 	if Service.EnableTimetracking {
 		Service.DefaultEnableTimetracking = sec.Key("DEFAULT_ENABLE_TIMETRACKING").MustBool(true)

modules/validation/helpers.go

@@ -92,13 +92,20 @@ func IsValidExternalTrackerURLFormat(uri string) bool {
 }
 
 var (
-	validUsernamePattern   = regexp.MustCompile(`^[\da-zA-Z][-.\w]*$`)
-	invalidUsernamePattern = regexp.MustCompile(`[-._]{2,}|[-._]$`) // No consecutive or trailing non-alphanumeric chars
+	validUsernamePatternWithDots    = regexp.MustCompile(`^[\da-zA-Z][-.\w]*$`)
+	validUsernamePatternWithoutDots = regexp.MustCompile(`^[\da-zA-Z][-\w]*$`)
+
+	// No consecutive or trailing non-alphanumeric chars, catches both cases
+	invalidUsernamePattern = regexp.MustCompile(`[-._]{2,}|[-._]$`)
 )
 
 // IsValidUsername checks if username is valid
 func IsValidUsername(name string) bool {
 	// It is difficult to find a single pattern that is both readable and effective,
 	// but it's easier to use positive and negative checks.
-	return validUsernamePattern.MatchString(name) && !invalidUsernamePattern.MatchString(name)
+	if setting.Service.AllowDotsInUsernames {
+		return validUsernamePatternWithDots.MatchString(name) && !invalidUsernamePattern.MatchString(name)
+	}
+
+	return validUsernamePatternWithoutDots.MatchString(name) && !invalidUsernamePattern.MatchString(name)
 }

modules/validation/helpers_test.go

@@ -155,7 +155,8 @@ func Test_IsValidExternalTrackerURLFormat(t *testing.T) {
 	}
 }
 
-func TestIsValidUsername(t *testing.T) {
+func TestIsValidUsernameAllowDots(t *testing.T) {
+	setting.Service.AllowDotsInUsernames = true
 	tests := []struct {
 		arg  string
 		want bool
@@ -185,3 +186,31 @@ func TestIsValidUsername(t *testing.T) {
 		})
 	}
 }
+
+func TestIsValidUsernameBanDots(t *testing.T) {
+	setting.Service.AllowDotsInUsernames = false
+	defer func() {
+		setting.Service.AllowDotsInUsernames = true
+	}()
+
+	tests := []struct {
+		arg  string
+		want bool
+	}{
+		{arg: "a", want: true},
+		{arg: "abc", want: true},
+		{arg: "0.b-c", want: false},
+		{arg: "a.b-c_d", want: false},
+		{arg: ".abc", want: false},
+		{arg: "abc.", want: false},
+		{arg: "a..bc", want: false},
+		{arg: "a...bc", want: false},
+		{arg: "a.-bc", want: false},
+		{arg: "a._bc", want: false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.arg, func(t *testing.T) {
+			assert.Equalf(t, tt.want, IsValidUsername(tt.arg), "IsValidUsername[AllowDotsInUsernames=false](%v)", tt.arg)
+		})
+	}
+}

modules/web/middleware/binding.go

@@ -8,6 +8,7 @@ import (
 	"reflect"
 	"strings"
 
+	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/translation"
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/modules/validation"
@@ -135,7 +136,11 @@ func Validate(errs binding.Errors, data map[string]any, f Form, l translation.Lo
 			case validation.ErrRegexPattern:
 				data["ErrorMsg"] = trName + l.Tr("form.regex_pattern_error", errs[0].Message)
 			case validation.ErrUsername:
+				if setting.Service.AllowDotsInUsernames {
 					data["ErrorMsg"] = trName + l.Tr("form.username_error")
+				} else {
+					data["ErrorMsg"] = trName + l.Tr("form.username_error_no_dots")
+				}
 			case validation.ErrInvalidGroupTeamMap:
 				data["ErrorMsg"] = trName + l.Tr("form.invalid_group_team_map_error", errs[0].Message)
 			default:

options/locale/locale_en-US.ini

@@ -291,6 +291,7 @@ default_allow_create_organization = Allow Creation of Organizations by Default
 default_allow_create_organization_popup = Allow new user accounts to create organizations by default.
 default_enable_timetracking = Enable Time Tracking by Default
 default_enable_timetracking_popup = Enable time tracking for new repositories by default.
+allow_dots_in_usernames = Allow users to use dots in their usernames. Doesn't affect existing accounts.
 no_reply_address = Hidden Email Domain
 no_reply_address_helper = Domain name for users with a hidden email address. For example, the username 'joe' will be logged in Git as 'joe@noreply.example.org' if the hidden email domain is set to 'noreply.example.org'.
 password_algorithm = Password Hash Algorithm
@@ -529,6 +530,7 @@ include_error = ` must contain substring "%s".`
 glob_pattern_error = ` glob pattern is invalid: %s.`
 regex_pattern_error = ` regex pattern is invalid: %s.`
 username_error = ` can only contain alphanumeric chars ('0-9','a-z','A-Z'), dash ('-'), underscore ('_') and dot ('.'). It cannot begin or end with non-alphanumeric chars, and consecutive non-alphanumeric chars are also forbidden.`
+username_error_no_dots = ` can only contain alphanumeric chars ('0-9','a-z','A-Z'), dash ('-') and underscore ('_'). It cannot begin or end with non-alphanumeric chars, and consecutive non-alphanumeric chars are also forbidden.`
 invalid_group_team_map_error = ` mapping is invalid: %s`
 unknown_error = Unknown error:
 captcha_incorrect = The CAPTCHA code is incorrect.

templates/admin/config.tmpl

@@ -159,6 +159,8 @@
 				<dd>{{if .Service.DefaultKeepEmailPrivate}}{{svg "octicon-check"}}{{else}}{{svg "octicon-x"}}{{end}}</dd>
 				<dt>{{.locale.Tr "admin.config.default_allow_create_organization"}}</dt>
 				<dd>{{if .Service.DefaultAllowCreateOrganization}}{{svg "octicon-check"}}{{else}}{{svg "octicon-x"}}{{end}}</dd>
+				<dt>{{.locale.Tr "admin.config.allow_dots_in_usernames"}}</dt>
+				<dd>{{if .Service.AllowDotsInUsernames}}{{svg "octicon-check"}}{{else}}{{svg "octicon-x"}}{{end}}</dd>
 				<dt>{{.locale.Tr "admin.config.enable_timetracking"}}</dt>
 				<dd>{{if .Service.EnableTimetracking}}{{svg "octicon-check"}}{{else}}{{svg "octicon-x"}}{{end}}</dd>
 				{{if .Service.EnableTimetracking}}