diff --git a/src/main/java/minsecurity/identity/persist/sqlite/Sqlite.java b/src/main/java/minsecurity/identity/persist/sqlite/Sqlite.java
index bc2ffa4..cd4d468 100644
--- a/src/main/java/minsecurity/identity/persist/sqlite/Sqlite.java
+++ b/src/main/java/minsecurity/identity/persist/sqlite/Sqlite.java
@@ -64,12 +64,13 @@ public class Sqlite {
         Statement stmt = null;
         try{
             String homePath = SqliteUtil.home();
-            homePath += "/min/identity";
+            homePath += "/min/identity/";
             String dbPath = homePath;
             if (!SqliteUtil.pathExists(dbPath)){
                 new File(dbPath).mkdirs();
             }
             String real_db_file = dbPath + db_file;
+            Class.forName("org.sqlite.JDBC");
             c = DriverManager.getConnection("jdbc:sqlite:" + real_db_file);
             stmt = c.createStatement();
             stmt.executeUpdate(table_create);
@@ -91,6 +92,7 @@ public class Sqlite {
                 new File(filePath).mkdirs();
             }
             String real_db_file = filePath + db_file;
+            Class.forName("org.sqlite.JDBC");
             c = DriverManager.getConnection("jdbc:sqlite:" + real_db_file);
             stmt = c.createStatement();
             stmt.executeUpdate(table_create);
@@ -104,10 +106,11 @@ public class Sqlite {
         }
     }
 
-    public Connection getConn() throws SQLException {
+    public Connection getConn() throws Exception {
         Connection c = null;
         try{
             String real_db_file = db_path + db_file;
+            Class.forName("org.sqlite.JDBC");
             c = DriverManager.getConnection("jdbc:sqlite:" + real_db_file);
             // TODO 设置数据库最大连接数
             return c;
diff --git a/src/main/java/minsecurity/identity/persist/sqlite/db/Db.java b/src/main/java/minsecurity/identity/persist/sqlite/db/Db.java
index 8198d7a..0043580 100644
--- a/src/main/java/minsecurity/identity/persist/sqlite/db/Db.java
+++ b/src/main/java/minsecurity/identity/persist/sqlite/db/Db.java
@@ -1,4 +1,170 @@
 package minsecurity.identity.persist.sqlite.db;
 
-public class Db {
+import minsecurity.Common;
+import minsecurity.certificate.cert.CertUtils;
+import minsecurity.certificate.cert.Certificate;
+import minsecurity.crypto.KeyUtils;
+import minsecurity.crypto.PrivateKeyInterface;
+import minsecurity.crypto.PublicKeyInterface;
+import minsecurity.identity.Identity;
+import minsecurity.identity.KeyParam;
+import minsecurity.identity.persist.sqlite.Sqlite;
+
+import java.sql.*;
+import java.util.ArrayList;
+import java.util.Base64;
+import java.util.List;
+
+public final class Db {
+    private static Identity getIdentityByNameFromStorage(String name, Connection c) throws Exception {
+        Statement stmt = c.createStatement();
+        ResultSet rs = stmt.executeQuery(String.format("SELECT * FROM identityinfo WHERE name = %s LIMIT 1", name)); // LIMIT 1代替Queryrow
+        stmt.close();
+        return getIdentityFromSqlRow(rs);
+    }
+
+    private static Identity getIdentityFromSqlRow(ResultSet rs) throws Exception {
+        if (!rs.isBeforeFirst())
+            return null;
+
+        String pubStr = "", priStr = "", pass = "", certStr = "", name = "", prikeyRawByte = "";
+        int algo = 0, sign = 0, def = 0;
+
+        while (rs.next()){
+            pubStr = rs.getString("pubKey");
+            priStr = rs.getString("priKey");
+            pass = rs.getString("pass");
+            certStr = rs.getString("cert");
+            name = rs.getString("name");
+            prikeyRawByte = rs.getString("prikey_raw_byte");
+            algo = rs.getInt("pubkey_algo");
+            sign = rs.getInt("signature_algo");
+            def = rs.getInt("is_default");
+        }
+
+        byte[] pubByte = Base64.getDecoder().decode(pubStr);
+        PublicKeyInterface pubKey = KeyUtils.unMarshalPublicKey(pubByte, algo);
+        byte[] priByte = Base64.getDecoder().decode(priStr);
+        PrivateKeyInterface priKey = KeyUtils.unMarshalPrivateKey(priByte, algo);
+
+        Certificate cert = CertUtils.fromPem(certStr, null, Common.SM4ECB);
+        byte[] priKeyByte = Base64.getDecoder().decode(prikeyRawByte);
+        KeyParam keyParam = new KeyParam(algo, sign);
+        return new Identity(name, keyParam, priKey, priKeyByte, pubKey, pass, cert, def == 1);
+    }
+
+    private static List<Identity> getIdentityFromSqlRows(ResultSet rs) throws Exception {
+        if (!rs.isBeforeFirst())
+            return new ArrayList<>();
+
+        List<Identity> res = new ArrayList<>();
+        String pubStr = "", priStr = "", pass = "", certStr = "", name = "", prikeyRawByte = "";
+        int algo = 0, sign = 0, def = 0;
+
+        while (rs.next()){
+            pubStr = rs.getString("pubKey");
+            priStr = rs.getString("priKey");
+            pass = rs.getString("pass");
+            certStr = rs.getString("cert");
+            name = rs.getString("name");
+            prikeyRawByte = rs.getString("prikey_raw_byte");
+            algo = rs.getInt("pubkey_algo");
+            sign = rs.getInt("signature_algo");
+            def = rs.getInt("is_default");
+            byte[] pubByte = Base64.getDecoder().decode(pubStr);
+            PublicKeyInterface pubKey = KeyUtils.unMarshalPublicKey(pubByte, algo);
+            byte[] priByte = Base64.getDecoder().decode(priStr);
+            PrivateKeyInterface priKey = KeyUtils.unMarshalPrivateKey(priByte, algo);
+
+            Certificate cert = CertUtils.fromPem(certStr, null, Common.SM4ECB);
+            byte[] priKeyByte = Base64.getDecoder().decode(prikeyRawByte);
+            KeyParam keyParam = new KeyParam(algo, sign);
+            res.add(new Identity(name, keyParam, priKey, priKeyByte, pubKey, pass, cert, def == 1));
+        }
+
+        return res;
+    }
+
+    private static Identity getDefaultIdentityFromStorage(ResultSet rs) throws Exception{
+        if (rs == null)
+            return null;
+
+        String pubStr = "", priStr = "", pass = "", certStr = "", name = "", prikeyRawByte = "";
+        int algo = 0, sign = 0, def = 0;
+
+        while (rs.next()){
+            pubStr = rs.getString("pubKey");
+            priStr = rs.getString("priKey");
+            pass = rs.getString("pass");
+            certStr = rs.getString("cert");
+            name = rs.getString("name");
+            prikeyRawByte = rs.getString("prikey_raw_byte");
+            algo = rs.getInt("pubkey_algo");
+            sign = rs.getInt("signature_algo");
+            def = rs.getInt("is_default");
+        }
+
+        byte[] pubByte = Base64.getDecoder().decode(pubStr);
+        PublicKeyInterface pubKey = KeyUtils.unMarshalPublicKey(pubByte, algo);
+        byte[] priByte = Base64.getDecoder().decode(priStr);
+        PrivateKeyInterface priKey = KeyUtils.unMarshalPrivateKey(priByte, algo);
+
+        Certificate cert = CertUtils.fromPem(certStr, null, Common.SM4ECB);
+        byte[] priKeyByte = Base64.getDecoder().decode(prikeyRawByte);
+        KeyParam keyParam = new KeyParam(algo, sign);
+        return new Identity(name, keyParam, priKey, priKeyByte, pubKey, pass, cert, def == 1);
+    }
+
+
+    private static boolean setDefaultIdentityFromStorage(String name, Connection c) throws Exception{
+        PreparedStatement stmt = c.prepareStatement("update identityinfo set is_default = 1 where name= ?");
+        stmt.setString(1, name);
+        stmt.executeUpdate();
+        stmt.close();
+        return true;
+    }
+
+    private static boolean cancelDefaultIdentityFromStorage(String name, Connection c) throws Exception{
+        PreparedStatement stmt = c.prepareStatement("update identityinfo set is_default = 0 where name= ?");
+        stmt.setString(1, name);
+        stmt.executeUpdate();
+        stmt.close();
+        return true;
+    }
+
+    public static List<Identity> getAllIdentityFromStorage(String name) throws Exception {
+        Connection c = Sqlite.getInstance().getConn();
+        Statement stmt = c.createStatement();
+        ResultSet rs = stmt.executeQuery("SELECT * from identityinfo");
+        stmt.close();
+        c.close();
+        List<Identity> res = getIdentityFromSqlRows(rs);
+        return res;
+    }
+
+    public static Identity getIdentityByNameFromStorage(String name) throws Exception {
+        Connection c = Sqlite.getInstance().getConn();
+        c.close();
+        return getIdentityByNameFromStorage(name, c);
+    }
+
+    private static boolean setDefaultIdentityByNameInStorage(String name) throws Exception {
+        Connection c = Sqlite.getInstance().getConn();
+        return false;
+    }
+    public static boolean SetDefaultIdentityByNameInStorage(String name) throws Exception {
+        for (int i = 0; i < 4; i++){
+            boolean res = false;
+            try{
+                res = setDefaultIdentityByNameInStorage(name);
+                return res;
+            }catch (Exception ex){
+                if (ex.getMessage().equals("database is locked"))
+                    Thread.sleep(50);
+                else
+                    return false;
+            }
+        }
+        return false;
+    }
 }
diff --git a/src/main/java/minsecurity/identity/persist/sqlite/db/Internal.java b/src/main/java/minsecurity/identity/persist/sqlite/db/Internal.java
deleted file mode 100644
index 11433d0..0000000
--- a/src/main/java/minsecurity/identity/persist/sqlite/db/Internal.java
+++ /dev/null
@@ -1,4 +0,0 @@
-package minsecurity.identity.persist.sqlite.db;
-
-public class Internal {
-}