diff --git a/src/main/java/com/sunyard/util/CertUtil.java b/src/main/java/com/sunyard/util/CertUtil.java
index 2a40df6..73ac14a 100644
--- a/src/main/java/com/sunyard/util/CertUtil.java
+++ b/src/main/java/com/sunyard/util/CertUtil.java
@@ -1,21 +1,22 @@
 package com.sunyard.util;
 
 import cn.hutool.core.codec.Base64;
+import com.sunyard.RetWrap;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import sun.misc.BASE64Encoder;
 
 import java.io.ByteArrayInputStream;
+import java.io.IOException;
 import java.security.NoSuchProviderException;
 import java.security.Security;
 import java.security.cert.CertificateEncodingException;
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
-import java.util.Map;
 
 public class CertUtil {
-    public static String encodeBase64(byte[] data){
-        return new BASE64Encoder().encode( data );
+    public static String encodeBase64(byte[] data) {
+        return new BASE64Encoder().encode(data);
     }
 
     static {
@@ -70,6 +71,7 @@ public class CertUtil {
 
     /**
      * 判断正式是否是国密证书
+     *
      * @param cert 证书 base64 字符
      * @return true 国密， false 非国密
      */
@@ -81,12 +83,13 @@ public class CertUtil {
 
     /**
      * 判断 p7 是否是国密证书签的
+     *
      * @param pkcs7 pkcs7
      * @return true 国密， false 非国密
      */
-    public static boolean isSignedBySM2Cert( String pkcs7 ){
-        return false;
+    public static boolean isSignedBySM2Cert(String pkcs7) throws IOException, CertificateException, NoSuchProviderException {
+        RetWrap ret = ASN1Util.takeOutOriginDataFromPKCS7Sign(pkcs7);
+        return isSM2Cert((String) ret.get("cert"));
     }
 
-
 }