updated as per the review comments

pkg/plugin/definition/signvalidator.go

@@ -0,0 +1,15 @@
+package definition
+
+import "context"
+
+// SignValidator defines the method for verifying signatures.
+type SignValidator interface {
+	// Validate checks the validity of the signature for the given body.
+	Validate(ctx context.Context, body []byte, header string, publicKeyBase64 string) error
+}
+
+// SignValidatorProvider initializes a new Verifier instance with the given config.
+type SignValidatorProvider interface {
+	// New creates a new Verifier instance based on the provided config.
+	New(ctx context.Context, config map[string]string) (SignValidator, func() error, error)
+}