Connecting to an RDS for MySQL Instance Through JDBC

If you are connecting to an instance through JDBC, an SSL certificate is optional, but using an SSL certificate can improve the security of your data. SSL is disabled by default for newly created instances. You can enable SSL by referring to Configuring an SSL Connection. SSL encrypts connections to your instances but it increases the connection response time and CPU usage. For this reason, enabling SSL is not recommended.

Prerequisites

You are familiar with:

Computer basics.
Java.
JDBC.

Connection with the SSL Certificate

Download the SSL certificate and verify it before connecting to your instance. RDS for MySQL DB instances do not support X.509-based authentication.

Download the CA certificate or certificate bundle.
1. On the Instances page, click the instance name to go to the Overview page.
2. Under SSL, click Download.

Use keytool to generate a truststore file using the CA certificate.

<keytool installation path> ./keytool.exe -importcert -alias <MySQLCACert> -file <ca.pem> -keystore <truststore_file> -storepass <password>

**Table 1** Parameter description
Parameter	Description
<keytool installation path>	Bin directory in the JDK or JRE installation path, for example, C:\Program Files (x86)\Java\jdk11.0.7\bin.
<MySQLCACert>	Name of the truststore file. Set it to a name specific to the service for future identification.
<ca.pem>	Name of the CA certificate downloaded and decompressed in 1, for example, ca.pem.
<truststore_file>	Path for storing the truststore file.
<password>	Password of the truststore file.

Code example (using keytool in the JDK installation path to generate the truststore file):

Owner:  CN=MySQL_Server_5.7.17_Auto_Generated_CA_Certificate
Issuer: CN=MySQL_Server_5.7.17_Auto_Generated_CA_Certificate 
Serial number: 1
Valid from: Thu Feb 16 11:42:43 EST 2017 until: Sun Feb 14 11:42:43 EST 2027 
Certificate fingerprints:
     MD5: 18:87:97:37:EA:CB:0B:5A:24:AB:27:76:45:A4:78:C1
     SHA1: 2B:0D:D9:69:2C:99:BF:1E:2A:25:4E:8D:2D:38:B8:70:66:47:FA:ED 
     SHA256:C3:29:67:1B:E5:37:06:F7:A9:93:DF:C7:B3:27:5E:09:C7:FD:EE:2D:18:86:F4:9C:40:D8:26:CB:DA:95: A0:24
     Signature algorithm name: SHA256withRSA Subject Public Key Algorithm: 2048-bit RSA key 
     Version: 1
     Trust this certificate? [no]: y
     Certificate was added to keystore

Connect to your RDS for MySQL instance through JDBC.

jdbc:mysql://<instance_ip>:<instance_port>/<database_name>?param1=value1&param2=value2

**Table 2** Parameter description
Parameter	Description
<instance_ip>	IP address of the DB instance. NOTE: If you are accessing the DB instance through an ECS, instance_ip is the floating IP address of the instance. You can obtain this IP address on the Connectivity & Security page. If you are accessing the DB instance through a public network, instance_ip indicates the EIP that has been bound to the instance. You can obtain this IP address on the Connectivity & Security page.
<instance_port>	Database port of the DB instance. The default port is 3306. NOTE: You can obtain this port number on the Connectivity & Security page.
<database_name>	Database name used for connecting to the DB instance. The default value is mysql.
<param1>	requireSSL, indicating whether the server supports SSL. Its value can be either of the following: true: The server supports SSL. false: The server does not support SSL. NOTE: For details about the relationship between requireSSL and sslmode, see Table 3.
<param2>	useSSL, indicating whether the client uses SSL to connect to the server. Its value can be either of the following: true: The client uses SSL to connect to the server. false: The client does not use SSL to connect to the server. NOTE: For details about the relationship between useSSL and sslmode, see Table 3.
<param3>	verifyServerCertificate, indicating whether the client verifies the server certificate. It can be either of the following: true: The client verifies the server certificate. false: The client does not verify the server certificate. NOTE: For details about the relationship between verifyServerCertificate and sslmode, see Table 3.
<param4>	trustCertificateKeyStoreUrl. Its value is file:<truststore_file>. Replace <truststore_file> with the path for storing the truststore file set in 2.
<param5>	trustCertificateKeyStorePassword. Its value is the password of the truststore file set in 2.

**Table 3** Relationship between connection parameters and sslmode
useSSL	requireSSL	verifyServerCertificate	sslMode
false	N/A	N/A	DISABLED
true	false	false	PREFERRED
true	true	false	REQUIRED
true	N/A	true	VERIFY_CA

Code example (Java code for connecting to an RDS for MySQL instance):

import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.ResultSet; 
import java.sql.Statement;
import java.sql.SQLException; 

// There will be security risks if the username and password used for authentication are directly written into code. Store the username and password in ciphertext in the configuration file or environment variables.
// In this example, the username and password are stored in the environment variables. Before running this example, set environment variables EXAMPLE_USERNAME_ENV and EXAMPLE_PASSWORD_ENV as needed.
public class JDBCTest { 
   

    String USER = System.getenv("EXAMPLE_USERNAME_ENV");         
    String PASS = System.getenv("EXAMPLE_PASSWORD_ENV");

    public static void main(String[] args) {
        Connection conn = null; 
        Statement stmt = null;

       // Set the required parameters in the URL based on the site requirements.
       String url = "jdbc:mysql://<instance_ip>:<instance_port>/<database_name>?param1=value1&param2=value2";
 
        try { 
            Class.forName("com.mysql.cj.jdbc.Driver");
            conn = DriverManager.getConnection(url, USER, PASS);
 
            stmt = conn.createStatement(); 
            String sql = "show status like 'ssl%'";
            ResultSet rs = stmt.executeQuery(sql); 

            int columns = rs.getMetaData().getColumnCount();
            for (int i = 1; i <= columns; i++) {
                System.out.print(rs.getMetaData().getColumnName(i));
                System.out.print("\t");
            }

            while (rs.next()) { 
                System.out.println(); 
                for (int i = 1; i <= columns; i++) {
                    System.out.print(rs.getObject(i));
                    System.out.print("\t");
                } 
            }
            rs.close(); 
            stmt.close(); 
            conn.close(); 
        } catch (SQLException se) { 
            se.printStackTrace(); 
        } catch (Exception e) { 
            e.printStackTrace(); 
        } finally { 
            // release resource .... 
        } 
    } 
}

Connection Without the SSL Certificate

You do not need to download the SSL certificate because certificate verification on the server is not required.

Connect to the RDS for MySQL DB instance through JDBC.

jdbc:mysql://<instance_ip>:<instance_port>/<database_name>?useSSL=false

**Table 4** Parameter description
Parameter	Description
<instance_ip>	IP address of the DB instance. NOTE: If you are accessing the DB instance through an ECS, instance_ip is the floating IP address of the instance. You can obtain this IP address on the Connectivity & Security page. If you are accessing the DB instance through a public network, instance_ip indicates the EIP that has been bound to the instance. You can obtain this IP address on the Connectivity & Security page.
<instance_port>	Database port of the DB instance. The default port is 3306. NOTE: You can obtain this port number on the Connectivity & Security page.
<database_name>	Database name used for connecting to the DB instance. The default value is mysql.

Code example (Java code for connecting to an RDS for MySQL instance):

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
// There will be security risks if the username and password used for authentication are directly written into code. Store the username and password in ciphertext in the configuration file or environment variables.
// In this example, the username and password are stored in the environment variables. Before running this example, set environment variables EXAMPLE_USERNAME_ENV and EXAMPLE_PASSWORD_ENV as needed.

public class MyConnTest {
	final public static void main(String[] args) {
		Connection conn = null;

                // Set the required parameters in the URL based on the site requirements.
                String url = "jdbc:mysql://<instance_ip>:<instance_port>/<database_name>?param1=value1&param2=value2";
                String USER = System.getenv("EXAMPLE_USERNAME_ENV");         
                String PASS = System.getenv("EXAMPLE_PASSWORD_ENV");
		try {
			Class.forName("com.mysql.jdbc.Driver");
			
                        conn = DriverManager.getConnection(url,USER,PASS);
			System.out.println("Database connected");

			Statement stmt = conn.createStatement();
			ResultSet rs = stmt.executeQuery("SELECT * FROM mytable WHERE columnfoo = 500");
			while (rs.next()) {
				System.out.println(rs.getString(1));
			}
			rs.close();
			stmt.close();
			conn.close();
		} catch (Exception e) {
			e.printStackTrace();
			System.out.println("Test failed");
		} finally {
			// release resource ....
		}
	}
}

Related Issues

Symptom

When you use JDK 8.0 or a later version to connect to an RDS for MySQL instance with an SSL certificate downloaded, an error similar to the following is reported:

javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or
cipher suites are inappropriate)
    at sun.security.ssl.HandshakeContext.<init>(HandshakeContext.java:171) ~[na:1.8.0_292]
    at sun.security.ssl.ClientHandshakeContext.<init>(ClientHandshakeContext.java:98) ~
[na:1.8.0_292]
    at sun.security.ssl.TransportContext.kickstart(TransportContext.java:220) ~
[na:1.8.0_292]
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:428) ~
[na:1.8.0_292]
    at
com.mysql.cj.protocol.ExportControlled.performTlsHandshake(ExportControlled.java:316) ~
[mysql-connector-java-8.0.17.jar:8.0.17]
    at
com.mysql.cj.protocol.StandardSocketFactory.performTlsHandshake(StandardSocketFactory.java
:188) ~[mysql-connector-java8.0.17.jar:8.0.17]
    at
com.mysql.cj.protocol.a.NativeSocketConnection.performTlsHandshake(NativeSocketConnection.
java:99) ~[mysql-connector-java8.0.17.jar:8.0.17]
    at
com.mysql.cj.protocol.a.NativeProtocol.negotiateSSLConnection(NativeProtocol.java:331) ~
[mysql-connector-java8.0.17.jar:8.0.17]
... 68 common frames omitted

Solution
Specify the corresponding parameter values in the code link of 3 based on the JAR package used by the client. Example:
- mysql-connector-java-5.1.xx.jar (For 8.0.18 and earlier versions, use the enabledTLSProtocols parameter. For details, see Connecting Securely Using SSL.)
```
In the database connection URL jdbc:mysql://<instance_ip>:<instance_port>/<database_name>?param1=value1&param2=value2, replace param1=value1 with enabledTLSProtocols=TLSv1.2.
```
- mysql-connector-java-8.0.xx.jar (For versions later than 8.0.18, use the tlsVersions parameter.)
```
In the database connection URL jdbc:mysql://<instance_ip>:<instance_port>/<database_name>?param1=value1&param2=value2, replace param1=value1 with tlsVersions=TLSv1.2.
```