diff --git a/crypto/crypto.go b/crypto/crypto.go
index 48c6599a..e2fa2af1 100644
--- a/crypto/crypto.go
+++ b/crypto/crypto.go
@@ -147,10 +147,31 @@ func parsePrivateKey(privateKeyStr string) (*rsa.PrivateKey, error) {
 func parsePublicKey(publicKeyStr string) (*rsa.PublicKey, error) {
 
 	publicKeyStr = strings.TrimSpace(publicKeyStr)
-	if !strings.HasPrefix(publicKeyStr, "-----BEGIN RSA PUBLIC KEY-----") {
+	if !strings.HasPrefix(publicKeyStr, "-----BEGIN RSA PUBLIC KEY-----") && !strings.HasPrefix(publicKeyStr, "-----BEGIN CERTIFICATE-----") {
 		publicKeyStr = fmt.Sprintf("-----BEGIN RSA PUBLIC KEY-----\n%s\n-----END RSA PUBLIC KEY-----\n", publicKeyStr)
 	}
 
+	// if it is a certificate, get the public key from the certificate
+	if strings.HasPrefix(publicKeyStr, "-----BEGIN CERTIFICATE-----") {
+
+		block, _ := pem.Decode([]byte(publicKeyStr))
+		if block == nil {
+			return nil, fmt.Errorf("cannot decode PEM block")
+		}
+
+		cert, err := x509.ParseCertificate(block.Bytes)
+		if err != nil {
+			return nil, err
+		}
+
+		pub, ok := cert.PublicKey.(*rsa.PublicKey)
+		if !ok {
+			return nil, errors.New("public key error")
+		}
+
+		return pub, nil
+	}
+
 	block, _ := pem.Decode([]byte(publicKeyStr))
 	if block == nil {
 		return nil, fmt.Errorf("cannot decode PEM block")