diff --git a/src/main/java/com/aliyun/gmsse/handshake/CertificateRequest.java b/src/main/java/com/aliyun/gmsse/handshake/CertificateRequest.java
index 573c965..8ce0656 100644
--- a/src/main/java/com/aliyun/gmsse/handshake/CertificateRequest.java
+++ b/src/main/java/com/aliyun/gmsse/handshake/CertificateRequest.java
@@ -66,7 +66,6 @@ public static CertificateRequest read(InputStream input) throws IOException {
             int nameLength = (input.read() & 0xFF) << 8 | (input.read() & 0xFF);
             byte[] encoding = new byte[nameLength];
             input.read(encoding, 0, nameLength);
-            // TODO:
             certificateAuthorities.add(encoding);
             count += nameLength + 2;
         }
diff --git a/src/main/java/com/aliyun/gmsse/protocol/ClientConnectionContext.java b/src/main/java/com/aliyun/gmsse/protocol/ClientConnectionContext.java
index 40e0feb..f8a35f3 100644
--- a/src/main/java/com/aliyun/gmsse/protocol/ClientConnectionContext.java
+++ b/src/main/java/com/aliyun/gmsse/protocol/ClientConnectionContext.java
@@ -29,7 +29,6 @@
 import com.aliyun.gmsse.Record;
 import com.aliyun.gmsse.SSLConfiguration;
 import com.aliyun.gmsse.SecurityParameters;
-import com.aliyun.gmsse.Util;
 import com.aliyun.gmsse.GMSSLSession.ID;
 import com.aliyun.gmsse.handshake.ClientHello;
 import com.aliyun.gmsse.record.Handshake;
diff --git a/src/main/java/com/aliyun/gmsse/protocol/ServerConnectionContext.java b/src/main/java/com/aliyun/gmsse/protocol/ServerConnectionContext.java
index 2e3df5b..2885ab6 100644
--- a/src/main/java/com/aliyun/gmsse/protocol/ServerConnectionContext.java
+++ b/src/main/java/com/aliyun/gmsse/protocol/ServerConnectionContext.java
@@ -16,7 +16,6 @@
 import javax.net.ssl.X509KeyManager;
 import javax.security.auth.x500.X500Principal;
 
-import org.bouncycastle.asn1.x500.X500Name;
 import org.bouncycastle.crypto.engines.SM4Engine;
 import org.bouncycastle.crypto.params.KeyParameter;
 import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPrivateKey;
@@ -35,7 +34,6 @@
 import com.aliyun.gmsse.Record;
 import com.aliyun.gmsse.SSLConfiguration;
 import com.aliyun.gmsse.SecurityParameters;
-import com.aliyun.gmsse.Util;
 import com.aliyun.gmsse.GMSSLSession.ID;
 import com.aliyun.gmsse.handshake.ClientHello;
 import com.aliyun.gmsse.record.Handshake;
diff --git a/src/test/java/com/aliyun/gmsse/server/ClientTest.java b/src/test/java/com/aliyun/gmsse/server/ClientTest.java
index 2d7f9e6..2e432c1 100644
--- a/src/test/java/com/aliyun/gmsse/server/ClientTest.java
+++ b/src/test/java/com/aliyun/gmsse/server/ClientTest.java
@@ -4,7 +4,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.io.OutputStream;
 import java.io.PrintWriter;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -15,7 +14,6 @@
 import java.security.NoSuchAlgorithmException;
 import java.security.UnrecoverableKeyException;
 import java.security.cert.CertificateException;
-import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
 import java.security.spec.InvalidKeySpecException;