org.sonar.api.config.AesCipher.java Source code

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Here is the source code for org.sonar.api.config.AesCipher.java

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/*
 * Sonar, open source software quality management tool.
 * Copyright (C) 2008-2012 SonarSource
 * mailto:contact AT sonarsource DOT com
 *
 * Sonar is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * Sonar is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Sonar; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
 */
package org.sonar.api.config;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Throwables;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.io.FileUtils;
import org.apache.commons.lang.StringUtils;
import org.sonar.api.CoreProperties;

import javax.annotation.Nullable;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import java.io.File;
import java.io.IOException;
import java.security.Key;
import java.security.SecureRandom;

final class AesCipher extends 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
    public static final int KEY_SIZE_IN_BITS = 128;

    private static final String CRYPTO_KEY = "AES";

    private final Settings settings;

    AesCipher(Settings settings) {
        this.settings = settings;
    }

    @Override
    String encrypt(String clearText) {
        try {
            javax.crypto.Cipher cipher = javax.crypto.Cipher.getInstance(CRYPTO_KEY);
            cipher.init(javax.crypto.Cipher.ENCRYPT_MODE, loadSecretFile());
            return new String(Base64.encodeBase64(cipher.doFinal(clearText.getBytes("UTF-8"))));
        } catch (Exception e) {
            throw Throwables.propagate(e);
        }
    }

    @Override
    String decrypt(String encryptedText) {
        try {
            javax.crypto.Cipher cipher = javax.crypto.Cipher.getInstance(CRYPTO_KEY);
            cipher.init(javax.crypto.Cipher.DECRYPT_MODE, loadSecretFile());
            byte[] cipherData = cipher.doFinal(Base64.decodeBase64(StringUtils.trim(encryptedText)));
            return new String(cipherData);
        } catch (Exception e) {
            throw Throwables.propagate(e);
        }
    }

    /**
     * This method checks the existence of the file, but not the validity of the contained key.
     */
    boolean hasSecretKey() {
        String path = getPathToSecretKey();
        if (StringUtils.isNotBlank(path)) {
            File file = new File(path);
            return file.exists() && file.isFile();
        }
        return false;
    }

    private Key loadSecretFile() throws IOException {
        String path = getPathToSecretKey();
        return loadSecretFileFromFile(path);
    }

    @VisibleForTesting
    Key loadSecretFileFromFile(@Nullable String path) throws IOException {
        if (StringUtils.isBlank(path)) {
            throw new IllegalStateException(
                    "Secret key not found. Please set the property " + CoreProperties.ENCRYPTION_SECRET_KEY_PATH);
        }
        File file = new File(path);
        if (!file.exists() || !file.isFile()) {
            throw new IllegalStateException("The property " + CoreProperties.ENCRYPTION_SECRET_KEY_PATH
                    + " does not link to a valid file: " + path);
        }
        String s = FileUtils.readFileToString(file);
        if (StringUtils.isBlank(s)) {
            throw new IllegalStateException("No secret key in the file: " + path);
        }
        return new SecretKeySpec(Base64.decodeBase64(StringUtils.trim(s)), CRYPTO_KEY);
    }

    String generateRandomSecretKey() {
        try {
            KeyGenerator keyGen = KeyGenerator.getInstance(CRYPTO_KEY);
            keyGen.init(KEY_SIZE_IN_BITS, new SecureRandom());
            SecretKey secretKey = keyGen.generateKey();
            return new String(Base64.encodeBase64(secretKey.getEncoded()));

        } catch (Exception e) {
            throw new IllegalStateException("Fail to generate secret key", e);
        }
    }

    @VisibleForTesting
    String getPathToSecretKey() {
        String path = settings.getClearString(CoreProperties.ENCRYPTION_SECRET_KEY_PATH);
        if (StringUtils.isBlank(path)) {
            path = new File(FileUtils.getUserDirectoryPath(), ".sonar/sonar-secret.txt").getPath();
        }
        return path;
    }
}