Conectar-se à instância de banco de dados usando a autenticação do IAM e o AWS SDK for Java

Você pode se conectar a uma instância de banco de dados do RDS para MariaDB, RDS para MySQL ou RDS para PostgreSQL com a AWS SDK for Java, conforme descrito a seguir.

Pré-requisitos

Veja a seguir os pré-requisitos para se conectar à instância de banco de dados usando a autenticação do IAM:

Consulte exemplos de como usar o SDK para Java 2.x em Amazon RDS examples using SDK for Java 2.x.

Gerar um token de autenticação do IAM

Se estiver escrevendo programas usando o AWS SDK for Java, você pode obter um token de autenticação assinado usando a classe RdsIamAuthTokenGenerator. O uso dessa classe exige que você forneça as credenciais da AWS. Para fazer isso, crie uma instância da classe DefaultAWSCredentialsProviderChain. DefaultAWSCredentialsProviderChain usa a primeira chave de acesso da AWS e a chave secreta encontradas na cadeia de fornecedores de credencial padrão. Para ter mais informações sobre chaves de acesso da AWS, consulte Gerenciar chaves de acesso para usuários.

Após criar uma instância de RdsIamAuthTokenGenerator, você pode chamar o método getAuthToken para obter um token assinado. Forneça a região da AWS, o nome do host, o número da porta e o nome do usuário. O exemplo de código a seguir ilustra como fazer isso.

package com.amazonaws.codesamples;

import com.amazonaws.auth.DefaultAWSCredentialsProviderChain;
import com.amazonaws.services.rds.auth.GetIamAuthTokenRequest;
import com.amazonaws.services.rds.auth.RdsIamAuthTokenGenerator;

public class GenerateRDSAuthToken {

    public static void main(String[] args) {

	    String region = "us-west-2";
	    String hostname = "rdsmysql.123456789012.us-west-2.rds.amazonaws.com";
	    String port = "3306";
	    String username = "jane_doe";
	
	    System.out.println(generateAuthToken(region, hostname, port, username));
    }

    static String generateAuthToken(String region, String hostName, String port, String username) {

	    RdsIamAuthTokenGenerator generator = RdsIamAuthTokenGenerator.builder()
		    .credentials(new DefaultAWSCredentialsProviderChain())
		    .region(region)
		    .build();

	    String authToken = generator.getAuthToken(
		    GetIamAuthTokenRequest.builder()
		    .hostname(hostName)
		    .port(Integer.parseInt(port))
		    .userName(username)
		    .build());
	    
	    return authToken;
    }

}

Criar manualmente um token de autenticação do IAM

No Java, o modo mais fácil de gerar um token de autenticação é usar o RdsIamAuthTokenGenerator. Essa classe cria um token de autenticação para você e assina-o usando o Signature da AWS versão 4. Para ter mais informações, consulte Processo de assinatura do Signature versão 4 na Referência geral da AWS.

No entanto, você também pode construir e assinar um token de autenticação manualmente, conforme mostrado no exemplo de código a seguir.

package com.amazonaws.codesamples;

import com.amazonaws.SdkClientException;
import com.amazonaws.auth.DefaultAWSCredentialsProviderChain;
import com.amazonaws.auth.SigningAlgorithm;
import com.amazonaws.util.BinaryUtils;
import org.apache.commons.lang3.StringUtils;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.SortedMap;
import java.util.TreeMap;

import static com.amazonaws.auth.internal.SignerConstants.AWS4_TERMINATOR;
import static com.amazonaws.util.StringUtils.UTF8;

public class CreateRDSAuthTokenManually {
    public static String httpMethod = "GET";
    public static String action = "connect";
    public static String canonicalURIParameter = "/";
    public static SortedMap<String, String> canonicalQueryParameters = new TreeMap();
    public static String payload = StringUtils.EMPTY;
    public static String signedHeader = "host";
    public static String algorithm = "AWS4-HMAC-SHA256";
    public static String serviceName = "rds-db";
    public static String requestWithoutSignature;

    public static void main(String[] args) throws Exception {

        String region = "us-west-2";
        String instanceName = "rdsmysql.123456789012.us-west-2.rds.amazonaws.com";
        String port = "3306";
        String username = "jane_doe";
	
        Date now = new Date();
        String date = new SimpleDateFormat("yyyyMMdd").format(now);
        String dateTimeStamp = new SimpleDateFormat("yyyyMMdd'T'HHmmss'Z'").format(now);
        DefaultAWSCredentialsProviderChain creds = new DefaultAWSCredentialsProviderChain();
	    String awsAccessKey = creds.getCredentials().getAWSAccessKeyId();
	    String awsSecretKey = creds.getCredentials().getAWSSecretKey();
        String expiryMinutes = "900";
        
        System.out.println("Step 1:  Create a canonical request:");
        String canonicalString = createCanonicalString(username, awsAccessKey, date, dateTimeStamp, region, expiryMinutes, instanceName, port);
        System.out.println(canonicalString);
        System.out.println();

        System.out.println("Step 2:  Create a string to sign:");        
        String stringToSign = createStringToSign(dateTimeStamp, canonicalString, awsAccessKey, date, region);
        System.out.println(stringToSign);
        System.out.println();

        System.out.println("Step 3:  Calculate the signature:");        
        String signature = BinaryUtils.toHex(calculateSignature(stringToSign, newSigningKey(awsSecretKey, date, region, serviceName)));
        System.out.println(signature);
        System.out.println();

        System.out.println("Step 4:  Add the signing info to the request");                
        System.out.println(appendSignature(signature));
        System.out.println();
        
    }

    //Step 1: Create a canonical request date should be in format YYYYMMDD and dateTime should be in format YYYYMMDDTHHMMSSZ
    public static String createCanonicalString(String user, String accessKey, String date, String dateTime, String region, String expiryPeriod, String hostName, String port) throws Exception {
        canonicalQueryParameters.put("Action", action);
        canonicalQueryParameters.put("DBUser", user);
        canonicalQueryParameters.put("X-Amz-Algorithm", "AWS4-HMAC-SHA256");
        canonicalQueryParameters.put("X-Amz-Credential", accessKey + "%2F" + date + "%2F" + region + "%2F" + serviceName + "%2Faws4_request");
        canonicalQueryParameters.put("X-Amz-Date", dateTime);
        canonicalQueryParameters.put("X-Amz-Expires", expiryPeriod);
        canonicalQueryParameters.put("X-Amz-SignedHeaders", signedHeader);
        String canonicalQueryString = "";
        while(!canonicalQueryParameters.isEmpty()) {
            String currentQueryParameter = canonicalQueryParameters.firstKey();
            String currentQueryParameterValue = canonicalQueryParameters.remove(currentQueryParameter);
            canonicalQueryString = canonicalQueryString + currentQueryParameter + "=" + currentQueryParameterValue;
            if (!currentQueryParameter.equals("X-Amz-SignedHeaders")) {
                canonicalQueryString += "&";
            }
        }
        String canonicalHeaders = "host:" + hostName + ":" + port + '\n';
        requestWithoutSignature = hostName + ":" + port + "/?" + canonicalQueryString;

        String hashedPayload = BinaryUtils.toHex(hash(payload));
        return httpMethod + '\n' + canonicalURIParameter + '\n' + canonicalQueryString + '\n' + canonicalHeaders + '\n' + signedHeader + '\n' + hashedPayload;

    }

    //Step 2: Create a string to sign using sig v4
    public static String createStringToSign(String dateTime, String canonicalRequest, String accessKey, String date, String region) throws Exception {
        String credentialScope = date + "/" + region + "/" + serviceName + "/aws4_request";
        return algorithm + '\n' + dateTime + '\n' + credentialScope + '\n' + BinaryUtils.toHex(hash(canonicalRequest));

    }

    //Step 3: Calculate signature
    /**
     * Step 3 of the &AWS; Signature version 4 calculation. It involves deriving
     * the signing key and computing the signature. Refer to
     * http://docs.aws.amazon
     * .com/general/latest/gr/sigv4-calculate-signature.html
     */
    public static byte[] calculateSignature(String stringToSign,
                                            byte[] signingKey) {
        return sign(stringToSign.getBytes(Charset.forName("UTF-8")), signingKey,
                SigningAlgorithm.HmacSHA256);
    }

    public static byte[] sign(byte[] data, byte[] key,
                          SigningAlgorithm algorithm) throws SdkClientException {
        try {
            Mac mac = algorithm.getMac();
            mac.init(new SecretKeySpec(key, algorithm.toString()));
            return mac.doFinal(data);
        } catch (Exception e) {
            throw new SdkClientException(
                    "Unable to calculate a request signature: "
                            + e.getMessage(), e);
        }
    }

    public static byte[] newSigningKey(String secretKey,
                                   String dateStamp, String regionName, String serviceName) {
        byte[] kSecret = ("AWS4" + secretKey).getBytes(Charset.forName("UTF-8"));
        byte[] kDate = sign(dateStamp, kSecret, SigningAlgorithm.HmacSHA256);
        byte[] kRegion = sign(regionName, kDate, SigningAlgorithm.HmacSHA256);
        byte[] kService = sign(serviceName, kRegion,
                SigningAlgorithm.HmacSHA256);
        return sign(AWS4_TERMINATOR, kService, SigningAlgorithm.HmacSHA256);
    }

    public static byte[] sign(String stringData, byte[] key,
                       SigningAlgorithm algorithm) throws SdkClientException {
        try {
            byte[] data = stringData.getBytes(UTF8);
            return sign(data, key, algorithm);
        } catch (Exception e) {
            throw new SdkClientException(
                    "Unable to calculate a request signature: "
                            + e.getMessage(), e);
        }
    }

    //Step 4: append the signature
    public static String appendSignature(String signature) {
        return requestWithoutSignature + "&X-Amz-Signature=" + signature;
    }

    public static byte[] hash(String s) throws Exception {
        try {
            MessageDigest md = MessageDigest.getInstance("SHA-256");
            md.update(s.getBytes(UTF8));
            return md.digest();
        } catch (Exception e) {
            throw new SdkClientException(
                    "Unable to compute hash while signing request: "
                            + e.getMessage(), e);
        }
    }
}

Conexão à instância de banco de dados

O exemplo de código a seguir mostra como gerar um token de autenticação e usá-lo para se conectar a uma instância que esteja executando o MariaDB ou o MySQL.

Para executar esse exemplo de código, você precisa do AWS SDK for Java, encontrado no site AWS. Além disso, você precisa do seguinte:

Esse exemplo de código obtém as credenciais da AWS a partir dacadeia de fornecedores de credencial padrão.

package com.amazonaws.samples;

import com.amazonaws.services.rds.auth.RdsIamAuthTokenGenerator;
import com.amazonaws.services.rds.auth.GetIamAuthTokenRequest;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.auth.DefaultAWSCredentialsProviderChain;
import com.amazonaws.auth.AWSStaticCredentialsProvider;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.security.KeyStore;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Properties;

import java.net.URL;

public class IAMDatabaseAuthenticationTester {
    //&AWS; Credentials of the IAM user with policy enabling IAM Database Authenticated access to the db by the db user.
    private static final DefaultAWSCredentialsProviderChain creds = new DefaultAWSCredentialsProviderChain();
    private static final String AWS_ACCESS_KEY = creds.getCredentials().getAWSAccessKeyId();
    private static final String AWS_SECRET_KEY = creds.getCredentials().getAWSSecretKey();

    //Configuration parameters for the generation of the IAM Database Authentication token
    private static final String RDS_INSTANCE_HOSTNAME = "rdsmysql.123456789012.us-west-2.rds.amazonaws.com";
    private static final int RDS_INSTANCE_PORT = 3306;
    private static final String REGION_NAME = "us-west-2";
    private static final String DB_USER = "jane_doe";
    private static final String JDBC_URL = "jdbc:mysql://" + RDS_INSTANCE_HOSTNAME + ":" + RDS_INSTANCE_PORT;

    private static final String SSL_CERTIFICATE = "rds-ca-2019-us-west-2.pem";

    private static final String KEY_STORE_TYPE = "JKS";
    private static final String KEY_STORE_PROVIDER = "SUN";
    private static final String KEY_STORE_FILE_PREFIX = "sys-connect-via-ssl-test-cacerts";
    private static final String KEY_STORE_FILE_SUFFIX = ".jks";
    private static final String DEFAULT_KEY_STORE_PASSWORD = "changeit";

    public static void main(String[] args) throws Exception {
        //get the connection
        Connection connection = getDBConnectionUsingIam();

        //verify the connection is successful
        Statement stmt= connection.createStatement();
        ResultSet rs=stmt.executeQuery("SELECT 'Success!' FROM DUAL;");
        while (rs.next()) {
        	    String id = rs.getString(1);
            System.out.println(id); //Should print "Success!"
        }

        //close the connection
        stmt.close();
        connection.close();
        
        clearSslProperties();
        
    }

    /**
     * This method returns a connection to the db instance authenticated using IAM Database Authentication
     * @return
     * @throws Exception
     */
    private static Connection getDBConnectionUsingIam() throws Exception {
        setSslProperties();
        return DriverManager.getConnection(JDBC_URL, setMySqlConnectionProperties());
    }

    /**
     * This method sets the mysql connection properties which includes the IAM Database Authentication token
     * as the password. It also specifies that SSL verification is required.
     * @return
     */
    private static Properties setMySqlConnectionProperties() {
        Properties mysqlConnectionProperties = new Properties();
        mysqlConnectionProperties.setProperty("verifyServerCertificate","true");
        mysqlConnectionProperties.setProperty("useSSL", "true");
        mysqlConnectionProperties.setProperty("user",DB_USER);
        mysqlConnectionProperties.setProperty("password",generateAuthToken());
        return mysqlConnectionProperties;
    }

    /**
     * This method generates the IAM Auth Token.
     * An example IAM Auth Token would look like follows:
     * btusi123---cmz7kenwo2ye---rds---cn-north-1.amazonaws.com.rproxy.goskope.com.cn:3306/?Action=connect&DBUser=iamtestuser&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20171003T010726Z&X-Amz-SignedHeaders=host&X-Amz-Expires=899&X-Amz-Credential=AKIAPFXHGVDI5RNFO4AQ%2F20171003%2Fcn-north-1%2Frds-db%2Faws4_request&X-Amz-Signature=f9f45ef96c1f770cdad11a53e33ffa4c3730bc03fdee820cfdf1322eed15483b
     * @return
     */
    private static String generateAuthToken() {
        BasicAWSCredentials awsCredentials = new BasicAWSCredentials(AWS_ACCESS_KEY, AWS_SECRET_KEY);

        RdsIamAuthTokenGenerator generator = RdsIamAuthTokenGenerator.builder()
                .credentials(new AWSStaticCredentialsProvider(awsCredentials)).region(REGION_NAME).build();
        return generator.getAuthToken(GetIamAuthTokenRequest.builder()
                .hostname(RDS_INSTANCE_HOSTNAME).port(RDS_INSTANCE_PORT).userName(DB_USER).build());
    }

    /**
     * This method sets the SSL properties which specify the key store file, its type and password:
     * @throws Exception
     */
    private static void setSslProperties() throws Exception {
        System.setProperty("javax.net.ssl.trustStore", createKeyStoreFile());
        System.setProperty("javax.net.ssl.trustStoreType", KEY_STORE_TYPE);
        System.setProperty("javax.net.ssl.trustStorePassword", DEFAULT_KEY_STORE_PASSWORD);
    }

    /**
     * This method returns the path of the Key Store File needed for the SSL verification during the IAM Database Authentication to
     * the db instance.
     * @return
     * @throws Exception
     */
    private static String createKeyStoreFile() throws Exception {
        return createKeyStoreFile(createCertificate()).getPath();
    }

    /**
     *  This method generates the SSL certificate
     * @return
     * @throws Exception
     */
    private static X509Certificate createCertificate() throws Exception {
        CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
        URL url = new File(SSL_CERTIFICATE).toURI().toURL();
        if (url == null) {
            throw new Exception();
        }
        try (InputStream certInputStream = url.openStream()) {
            return (X509Certificate) certFactory.generateCertificate(certInputStream);
        }
    }

    /**
     * This method creates the Key Store File
     * @param rootX509Certificate - the SSL certificate to be stored in the KeyStore
     * @return
     * @throws Exception
     */
    private static File createKeyStoreFile(X509Certificate rootX509Certificate) throws Exception {
        File keyStoreFile = File.createTempFile(KEY_STORE_FILE_PREFIX, KEY_STORE_FILE_SUFFIX);
        try (FileOutputStream fos = new FileOutputStream(keyStoreFile.getPath())) {
            KeyStore ks = KeyStore.getInstance(KEY_STORE_TYPE, KEY_STORE_PROVIDER);
            ks.load(null);
            ks.setCertificateEntry("rootCaCertificate", rootX509Certificate);
            ks.store(fos, DEFAULT_KEY_STORE_PASSWORD.toCharArray());
        }
        return keyStoreFile;
    }
    
    /**
     * This method clears the SSL properties.
     * @throws Exception
     */
    private static void clearSslProperties() throws Exception {
           System.clearProperty("javax.net.ssl.trustStore");
           System.clearProperty("javax.net.ssl.trustStoreType");
           System.clearProperty("javax.net.ssl.trustStorePassword"); 
    }
    
}

Se você quiser se conectar a uma instância de banco de dados por meio de um proxy, consulte Conectar-se a um proxy usando autenticação do IAM.