fix: shared renamed to pkg, formatting changes

pkg/plugin/definition/signVerifier.go

@@ -0,0 +1,22 @@
+package definition
+
+import "context"
+
+// Verifier defines the method for verifying signatures.
+type Verifier interface {
+	// Verify checks the validity of the signature for the given body.
+	Verify(ctx context.Context, body []byte, header []byte, publicKeyBase64 string) (bool, error)
+	Close() error // Close for releasing resources
+}
+
+// VerifierProvider initializes a new Verifier instance with the given config.
+type VerifierProvider interface {
+	// New creates a new Verifier instance based on the provided config.
+	New(ctx context.Context, config map[string]string) (Verifier, func() error, error)
+}
+
+// PublicKeyManager is the interface for key management plugin.
+type PublicKeyManager interface {
+	// PublicKey retrieves the public key for the given subscriberID and keyID.
+	PublicKey(ctx context.Context, subscriberID string, keyID string) (string, error)
+}