Merge branch 'feature/iam-15-timing-safe-vergleich-als-projektweite-coding-konvention' into feature/qa-05-abnahme-compliance-pruefung-core

internal/totp/totp.go

@@ -7,12 +7,13 @@ import (
 	"crypto/hmac"
 	"crypto/rand"
 	"crypto/sha1"
-	"crypto/subtle"
 	"encoding/base32"
 	"encoding/binary"
 	"fmt"
 	"net/url"
 	"time"
+
+	"gitea.perlbach24.de/scripte/nexarch/internal/timingsafe"
 )
 
 // StepSeconds ist das TOTP-Zeitfenster (RFC-6238-Standard: 30 Sekunden).
@@ -70,7 +71,7 @@ func Validate(secret, code string, t time.Time) (bool, error) {
 
 	for delta := -DefaultSkewSteps; delta <= DefaultSkewSteps; delta++ {
 		candidate := hotp(key, uint64(counter+int64(delta)))
-		if subtle.ConstantTimeCompare([]byte(candidate), []byte(code)) == 1 {
+		if timingsafe.EqualString(candidate, code) {
 			return true, nil
 		}
 	}