[release-v0.11] Automated cherry pick of #54: Fix mitigation for NoMa…

…tchingSignature error (#58)

* Fix mitigation for NoMatchingSignature error

The check introduced with #28 did not work

Co-authored-by: vpnachev <vladimir.nachev@sap.com>
Co-authored-by: ialidzhikov <i.alidjikov@gmail.com>

* Add additional log msg as per review

---------

Co-authored-by: Dimitar Mirchev <dimitar.mirchev@sap.com>
Co-authored-by: ialidzhikov <i.alidjikov@gmail.com>

pkg/lakom/verifysignature/verifier.go

@@ -87,9 +87,10 @@ func verify(ctx context.Context, imageRef name.Reference, keys []crypto.PublicKe
 			}
 
 			if IsNoMatchingSignature(err) {
-				if errors.Is(err, context.Canceled) {
+				if errors.Is(ctx.Err(), context.Canceled) || errors.Is(ctx.Err(), context.DeadlineExceeded) {
 					// Mitigation for https://github.com/gardener/gardener-extension-shoot-lakom-service/issues/25
 					// TODO(vpnachev): remove when https://github.com/sigstore/cosign/issues/3133 is fixed and vendored
+					log.Info("no matching signatures error detected as canceled or deadline exceeded context", "error", err)
 					return false, err
 				}