Implement allowPublicKeyRetrieval option in mysql datasource

src/main/java/fr/xephi/authme/datasource/MySQL.java

@@ -39,6 +39,7 @@ public class MySQL extends AbstractSqlDataSource {
 
     private boolean useSsl;
     private boolean serverCertificateVerification;
+    private boolean allowPublicKeyRetrieval;
     private String host;
     private String port;
     private String username;
@@ -118,6 +119,7 @@ public class MySQL extends AbstractSqlDataSource {
         this.maxLifetime = settings.getProperty(DatabaseSettings.MYSQL_CONNECTION_MAX_LIFETIME);
         this.useSsl = settings.getProperty(DatabaseSettings.MYSQL_USE_SSL);
         this.serverCertificateVerification = settings.getProperty(DatabaseSettings.MYSQL_CHECK_SERVER_CERTIFICATE);
+        this.allowPublicKeyRetrieval = settings.getProperty(DatabaseSettings.MYSQL_ALLOW_PUBLIC_KEY_RETRIEVAL);
     }
 
     /**
@@ -147,6 +149,9 @@ public class MySQL extends AbstractSqlDataSource {
         // Disabling server certificate verification on need
         if (!serverCertificateVerification) {
             ds.addDataSourceProperty("verifyServerCertificate", String.valueOf(false));
+        }        // Disabling server certificate verification on need
+        if (allowPublicKeyRetrieval) {
+            ds.addDataSourceProperty("allowPublicKeyRetrieval", String.valueOf(true));
         }
 
         // Encoding

src/main/java/fr/xephi/authme/settings/properties/DatabaseSettings.java

@@ -37,6 +37,11 @@ public final class DatabaseSettings implements SettingsHolder {
     public static final Property<Boolean> MYSQL_CHECK_SERVER_CERTIFICATE =
         newProperty( "DataSource.mySQLCheckServerCertificate", true );
 
+    @Comment({"Authorize client to retrieve RSA server public key.",
+        "Advanced option, ignore if you don't know what it means."})
+    public static final Property<Boolean> MYSQL_ALLOW_PUBLIC_KEY_RETRIEVAL =
+        newProperty( "DataSource.mySQLAllowPublicKeyRetrieval", true );
+
     @Comment("Username to connect to the MySQL database")
     public static final Property<String> MYSQL_USERNAME =
         newProperty("DataSource.mySQLUsername", "authme");