Class ToolDSA

security/src/main/java/pro/tools/security/ToolDSA.java:28–192

DSA安全编码组件 @author SeanDragon

 * @author SeanDragon
 */
public final class ToolDSA {
    private ToolDSA() {
        throw new UnsupportedOperationException("我是工具类，别初始化我。。。");
    }

    /**
     * 数字签名密钥算法
     */
    public static final String ALGORITHM = "DSA";

    /**
     * 数字签名 签名/验证算法
     */
    public static final String SIGNATURE_ALGORITHM = "SHA1withDSA";

    /**
     * 公钥
     */
    private static final String PUBLIC_KEY = "DSAPublicKey";

    /**
     * 私钥
     */
    private static final String PRIVATE_KEY = "DSAPrivateKey";

    /**
     * DSA密钥长度 默认1024位， 密钥长度必须是64的倍数， 范围在512至1024位之间（含）
     */
    private static final int KEY_SIZE = 1024;

    /**
     * 签名
     *
     * @param data
     *         待签名数据
     * @param privateKey
     *         私钥
     *
     * @return byte[] 数字签名
     *
     * @throws Exception
     */
    public static byte[] sign(byte[] data, byte[] privateKey) throws NoSuchAlgorithmException, InvalidKeySpecException, InvalidKeyException, SignatureException {
        // 还原私钥
        // 转换私钥材料
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(privateKey);

        // 实例化密钥工厂
        KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM);

        // 生成私钥对象
        PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);

        // 实例化Signature
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

        // 初始化Signature
        signature.initSign(priKey);