remove custom contains funcs for slices.Contains (#2015)

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

hscontrol/oidc.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"html/template"
 	"net/http"
+	"slices"
 	"strings"
 	"time"
 
@@ -365,7 +366,7 @@ func validateOIDCAllowedDomains(
 ) error {
 	if len(allowedDomains) > 0 {
 		if at := strings.LastIndex(claims.Email, "@"); at < 0 ||
-			!util.IsStringInSlice(allowedDomains, claims.Email[at+1:]) {
+			!slices.Contains(allowedDomains, claims.Email[at+1:]) {
 			log.Trace().Msg("authenticated principal does not match any allowed domain")
 
 			writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
@@ -393,7 +394,7 @@ func validateOIDCAllowedGroups(
 ) error {
 	if len(allowedGroups) > 0 {
 		for _, group := range allowedGroups {
-			if util.IsStringInSlice(claims.Groups, group) {
+			if slices.Contains(claims.Groups, group) {
 				return nil
 			}
 		}
@@ -420,7 +421,7 @@ func validateOIDCAllowedUsers(
 	claims *IDTokenClaims,
 ) error {
 	if len(allowedUsers) > 0 &&
-		!util.IsStringInSlice(allowedUsers, claims.Email) {
+		!slices.Contains(allowedUsers, claims.Email) {
 		log.Trace().Msg("authenticated principal does not match any allowed user")
 		writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
 		writer.WriteHeader(http.StatusBadRequest)

hscontrol/util/string.go

@@ -56,16 +56,6 @@ func GenerateRandomStringDNSSafe(size int) (string, error) {
 	return str[:size], nil
 }
 
-func IsStringInSlice(slice []string, str string) bool {
-	for _, s := range slice {
-		if s == str {
-			return true
-		}
-	}
-
-	return false
-}
-
 func TailNodesToString(nodes []*tailcfg.Node) string {
 	temp := make([]string, len(nodes))