SONAR-12841 Support AES 256 Settings Encryption

server/sonar-webserver-webapi/src/test/java/org/sonar/server/setting/ws/EncryptActionTest.java

 package org.sonar.server.setting.ws;
 
 import java.io.File;
+import java.nio.charset.StandardCharsets;
 import javax.annotation.Nullable;
 import org.apache.commons.io.FileUtils;
 import org.junit.Before;
     logInAsSystemAdministrator();
 
     File secretKeyFile = folder.newFile();
-    FileUtils.writeStringToFile(secretKeyFile, "fCVFf/JHRi8Qwu5KLNva7g==");
+    FileUtils.writeStringToFile(secretKeyFile, "fCVFf/JHRi8Qwu5KLNva7g==", StandardCharsets.UTF_8);
 
     encryption.setPathToSecretKey(secretKeyFile.getAbsolutePath());
   }

server/sonar-webserver-webapi/src/test/java/org/sonar/server/setting/ws/GenerateSecretKeyActionTest.java

 
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import org.apache.commons.io.FileUtils;
 import org.junit.Rule;
 import org.junit.Test;
 
     String secretKey = result.getSecretKey();
     File file = temporaryFolder.newFile();
-    FileUtils.writeStringToFile(file, secretKey);
+    FileUtils.writeStringToFile(file, secretKey, StandardCharsets.UTF_8);
     encryption.setPathToSecretKey(file.getAbsolutePath());
     String encryptedValue = encryption.encrypt("my value");
     String decryptedValue = encryption.decrypt(encryptedValue);

sonar-plugin-api-impl/src/main/java/org/sonar/api/config/internal/AesCipher.java

 import static java.nio.charset.StandardCharsets.UTF_8;
 
 final class AesCipher implements Cipher {
-
-  // Can't be increased because of Java 6 policy files :
-  // https://confluence.terena.org/display/~visser/No+256+bit+ciphers+for+Java+apps
-  // http://java.sun.com/javase/6/webnotes/install/jre/README
-  static final int KEY_SIZE_IN_BITS = 128;
+  static final int KEY_SIZE_IN_BITS = 256;
 
   private static final String CRYPTO_KEY = "AES";