EncryptUtils.java

package me.shouheng.utils.data;

import android.os.Build;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.DigestInputStream;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.KeyFactory;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import static me.shouheng.utils.data.EncodeUtils.base64Decode;
import static me.shouheng.utils.data.EncodeUtils.base64Encode;
import static me.shouheng.utils.data.StringUtils.bytes2HexString;
import static me.shouheng.utils.data.StringUtils.hexString2Bytes;
import static me.shouheng.utils.data.StringUtils.isSpace;

/**
 * The encrypt utils.
 *
 * @author Shouheng Wang (shouheng2020@gmail.com)
 * @version 2019/5/7 23:21
 */
public final class EncryptUtils {

    // region MD2

    public static String md2(final String data) {
        if (data == null || data.length() == 0) return "";
        return md2(data.getBytes());
    }

    public static String md2(final byte[] data) {
        return bytes2HexString(md2ToBytes(data));
    }

    public static byte[] md2ToBytes(final byte[] data) {
        return hashTemplate(data, "MD2");
    }

    // endregion

    // region MD5

    public static String md5(final String data) {
        if (data == null || data.length() == 0) return "";
        return md5(data.getBytes());
    }

    public static String md5(final String data, final String salt) {
        if (data == null && salt == null) return "";
        if (salt == null) return bytes2HexString(md5ToBytes(data.getBytes()));
        if (data == null) return bytes2HexString(md5ToBytes(salt.getBytes()));
        return bytes2HexString(md5ToBytes((data + salt).getBytes()));
    }

    public static String md5(final byte[] data) {
        return bytes2HexString(md5ToBytes(data));
    }

    public static String md5(final byte[] data, final byte[] salt) {
        if (data == null && salt == null) return "";
        if (salt == null) return bytes2HexString(md5ToBytes(data));
        if (data == null) return bytes2HexString(md5ToBytes(salt));
        byte[] dataSalt = new byte[data.length + salt.length];
        System.arraycopy(data, 0, dataSalt, 0, data.length);
        System.arraycopy(salt, 0, dataSalt, data.length, salt.length);
        return bytes2HexString(md5ToBytes(dataSalt));
    }

    public static byte[] md5ToBytes(final byte[] data) {
        return hashTemplate(data, "MD5");
    }

    public static String md5File(final String filePath) {
        File file = isSpace(filePath) ? null : new File(filePath);
        return md5File(file);
    }

    public static byte[] md5FileToBytes(final String filePath) {
        File file = isSpace(filePath) ? null : new File(filePath);
        return md5FileToBytes(file);
    }

    public static String md5File(final File file) {
        return bytes2HexString(md5FileToBytes(file));
    }

    public static byte[] md5FileToBytes(final File file) {
        if (file == null) return null;
        FileInputStream fis = null;
        DigestInputStream digestInputStream;
        try {
            fis = new FileInputStream(file);
            MessageDigest md = MessageDigest.getInstance("MD5");
            digestInputStream = new DigestInputStream(fis, md);
            byte[] buffer = new byte[256 * 1024];
            while (true) {
                if (!(digestInputStream.read(buffer) > 0)) break;
            }
            md = digestInputStream.getMessageDigest();
            return md.digest();
        } catch (NoSuchAlgorithmException | IOException e) {
            e.printStackTrace();
            return null;
        } finally {
            try {
                if (fis != null) {
                    fis.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    // endregion

    // region SHA1

    public static String sha1(final String data) {
        if (data == null || data.length() == 0) return "";
        return sha1(data.getBytes());
    }

    public static String sha1(final byte[] data) {
        return bytes2HexString(sha1ToBytes(data));
    }

    public static byte[] sha1ToBytes(final byte[] data) {
        return hashTemplate(data, "SHA1");
    }

    // endregion

    // region SHA224

    public static String sha224(final String data) {
        if (data == null || data.length() == 0) return "";
        return sha224(data.getBytes());
    }

    public static String sha224(final byte[] data) {
        return bytes2HexString(sha224ToBytes(data));
    }

    public static byte[] sha224ToBytes(final byte[] data) {
        return hashTemplate(data, "SHA224");
    }

    // endregion

    // region SHA256

    public static String sha256(final String data) {
        if (data == null || data.length() == 0) return "";
        return sha256(data.getBytes());
    }

    public static String sha256(final byte[] data) {
        return bytes2HexString(sha256ToBytes(data));
    }

    public static byte[] sha256ToBytes(final byte[] data) {
        return hashTemplate(data, "SHA256");
    }

    // endregion

    // region SHA384

    public static String sha384(final String data) {
        if (data == null || data.length() == 0) return "";
        return sha384(data.getBytes());
    }

    public static String sha384(final byte[] data) {
        return bytes2HexString(sha384ToBytes(data));
    }

    public static byte[] sha384ToBytes(final byte[] data) {
        return hashTemplate(data, "SHA384");
    }

    // endregion

    // region SHA512

    public static String sha512(final String data) {
        if (data == null || data.length() == 0) return "";
        return sha512(data.getBytes());
    }

    public static String sha512(final byte[] data) {
        return bytes2HexString(sha512ToBytes(data));
    }

    public static byte[] sha512ToBytes(final byte[] data) {
        return hashTemplate(data, "SHA512");
    }

    // endregion

    // region HmacMD5

    /**
     * Return the hex string of HmacMD5 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacMD5 encryption
     */
    public static String HmacMD5(final String data, final String key) {
        if (data == null || data.length() == 0 || key == null || key.length() == 0) return "";
        return HmacMD5(data.getBytes(), key.getBytes());
    }

    /**
     * Return the hex string of HmacMD5 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacMD5 encryption
     */
    public static String HmacMD5(final byte[] data, final byte[] key) {
        return bytes2HexString(HmacMD5ToBytes(data, key));
    }

    /**
     * Return the bytes of HmacMD5 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the bytes of HmacMD5 encryption
     */
    public static byte[] HmacMD5ToBytes(final byte[] data, final byte[] key) {
        return hmacTemplate(data, key, "HmacMD5");
    }

    // endregion

    // region HmacSHA1

    /**
     * Return the hex string of HmacSHA1 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA1 encryption
     */
    public static String HmacSHA1(final String data, final String key) {
        if (data == null || data.length() == 0 || key == null || key.length() == 0) return "";
        return HmacSHA1(data.getBytes(), key.getBytes());
    }

    /**
     * Return the hex string of HmacSHA1 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA1 encryption
     */
    public static String HmacSHA1(final byte[] data, final byte[] key) {
        return bytes2HexString(HmacSHA1ToBytes(data, key));
    }

    /**
     * Return the bytes of HmacSHA1 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the bytes of HmacSHA1 encryption
     */
    public static byte[] HmacSHA1ToBytes(final byte[] data, final byte[] key) {
        return hmacTemplate(data, key, "HmacSHA1");
    }

    // endregion

    // region HmacSHA224

    /**
     * Return the hex string of HmacSHA224 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA224 encryption
     */
    public static String HmacSHA224(final String data, final String key) {
        if (data == null || data.length() == 0 || key == null || key.length() == 0) return "";
        return HmacSHA224(data.getBytes(), key.getBytes());
    }

    /**
     * Return the hex string of HmacSHA224 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA224 encryption
     */
    public static String HmacSHA224(final byte[] data, final byte[] key) {
        return bytes2HexString(HmacSHA224ToBytes(data, key));
    }

    /**
     * Return the bytes of HmacSHA224 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the bytes of HmacSHA224 encryption
     */
    public static byte[] HmacSHA224ToBytes(final byte[] data, final byte[] key) {
        return hmacTemplate(data, key, "HmacSHA224");
    }

    // endregion

    // region HmacSHA256

    /**
     * Return the hex string of HmacSHA256 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA256 encryption
     */
    public static String HmacSHA256(final String data, final String key) {
        if (data == null || data.length() == 0 || key == null || key.length() == 0) return "";
        return HmacSHA256(data.getBytes(), key.getBytes());
    }

    /**
     * Return the hex string of HmacSHA256 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA256 encryption
     */
    public static String HmacSHA256(final byte[] data, final byte[] key) {
        return bytes2HexString(HmacSHA256ToBytes(data, key));
    }

    /**
     * Return the bytes of HmacSHA256 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the bytes of HmacSHA256 encryption
     */
    public static byte[] HmacSHA256ToBytes(final byte[] data, final byte[] key) {
        return hmacTemplate(data, key, "HmacSHA256");
    }

    // endregion

    // region HmacSHA384

    /**
     * Return the hex string of HmacSHA384 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA384 encryption
     */
    public static String HmacSHA384(final String data, final String key) {
        if (data == null || data.length() == 0 || key == null || key.length() == 0) return "";
        return HmacSHA384(data.getBytes(), key.getBytes());
    }

    /**
     * Return the hex string of HmacSHA384 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA384 encryption
     */
    public static String HmacSHA384(final byte[] data, final byte[] key) {
        return bytes2HexString(HmacSHA384ToBytes(data, key));
    }

    /**
     * Return the bytes of HmacSHA384 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the bytes of HmacSHA384 encryption
     */
    public static byte[] HmacSHA384ToBytes(final byte[] data, final byte[] key) {
        return hmacTemplate(data, key, "HmacSHA384");
    }

    // endregion

    // region HmacSHA512

    /**
     * Return the hex string of HmacSHA512 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA512 encryption
     */
    public static String HmacSHA512(final String data, final String key) {
        if (data == null || data.length() == 0 || key == null || key.length() == 0) return "";
        return HmacSHA512(data.getBytes(), key.getBytes());
    }

    /**
     * Return the hex string of HmacSHA512 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the hex string of HmacSHA512 encryption
     */
    public static String HmacSHA512(final byte[] data, final byte[] key) {
        return bytes2HexString(HmacSHA512ToBytes(data, key));
    }

    /**
     * Return the bytes of HmacSHA512 encryption.
     *
     * @param data The data.
     * @param key  The key.
     * @return the bytes of HmacSHA512 encryption
     */
    public static byte[] HmacSHA512ToBytes(final byte[] data, final byte[] key) {
        return hmacTemplate(data, key, "HmacSHA512");
    }

    // endregion

    // region DES

    /**
     * Return the Base64-encode bytes of DES encryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the Base64-encode bytes of DES encryption
     */
    public static byte[] encryptDES2Base64(final byte[] data,
                                           final byte[] key,
                                           final String transformation,
                                           final byte[] iv) {
        return base64Encode(encryptDES(data, key, transformation, iv));
    }

    /**
     * Return the hex string of DES encryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the hex string of DES encryption
     */
    public static String encryptDES2HexString(final byte[] data,
                                              final byte[] key,
                                              final String transformation,
                                              final byte[] iv) {
        return bytes2HexString(encryptDES(data, key, transformation, iv));
    }

    /**
     * Return the bytes of DES encryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of DES encryption
     */
    public static byte[] encryptDES(final byte[] data,
                                    final byte[] key,
                                    final String transformation,
                                    final byte[] iv) {
        return symmetricTemplate(data, key, "DES", transformation, iv, true);
    }

    /**
     * Return the bytes of DES decryption for Base64-encode bytes.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of DES decryption for Base64-encode bytes
     */
    public static byte[] decryptBase64DES(final byte[] data,
                                          final byte[] key,
                                          final String transformation,
                                          final byte[] iv) {
        return decryptDES(base64Decode(data), key, transformation, iv);
    }

    /**
     * Return the bytes of DES decryption for hex string.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of DES decryption for hex string
     */
    public static byte[] decryptHexStringDES(final String data,
                                             final byte[] key,
                                             final String transformation,
                                             final byte[] iv) {
        return decryptDES(hexString2Bytes(data), key, transformation, iv);
    }

    /**
     * Return the bytes of DES decryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of DES decryption
     */
    public static byte[] decryptDES(final byte[] data,
                                    final byte[] key,
                                    final String transformation,
                                    final byte[] iv) {
        return symmetricTemplate(data, key, "DES", transformation, iv, false);
    }

    // endregion

    // region 3DES

    /**
     * Return the Base64-encode bytes of 3DES encryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the Base64-encode bytes of 3DES encryption
     */
    public static byte[] encrypt3DES2Base64(final byte[] data,
                                            final byte[] key,
                                            final String transformation,
                                            final byte[] iv) {
        return base64Encode(encrypt3DES(data, key, transformation, iv));
    }

    /**
     * Return the hex string of 3DES encryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the hex string of 3DES encryption
     */
    public static String encrypt3DES2HexString(final byte[] data,
                                               final byte[] key,
                                               final String transformation,
                                               final byte[] iv) {
        return bytes2HexString(encrypt3DES(data, key, transformation, iv));
    }

    /**
     * Return the bytes of 3DES encryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of 3DES encryption
     */
    public static byte[] encrypt3DES(final byte[] data,
                                     final byte[] key,
                                     final String transformation,
                                     final byte[] iv) {
        return symmetricTemplate(data, key, "DESede", transformation, iv, true);
    }

    /**
     * Return the bytes of 3DES decryption for Base64-encode bytes.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of 3DES decryption for Base64-encode bytes
     */
    public static byte[] decryptBase64_3DES(final byte[] data,
                                            final byte[] key,
                                            final String transformation,
                                            final byte[] iv) {
        return decrypt3DES(base64Decode(data), key, transformation, iv);
    }

    /**
     * Return the bytes of 3DES decryption for hex string.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of 3DES decryption for hex string
     */
    public static byte[] decryptHexString3DES(final String data,
                                              final byte[] key,
                                              final String transformation,
                                              final byte[] iv) {
        return decrypt3DES(hexString2Bytes(data), key, transformation, iv);
    }

    /**
     * Return the bytes of 3DES decryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of 3DES decryption
     */
    public static byte[] decrypt3DES(final byte[] data,
                                     final byte[] key,
                                     final String transformation,
                                     final byte[] iv) {
        return symmetricTemplate(data, key, "DESede", transformation, iv, false);
    }

    // endregion

    // region AES

    /**
     * Return the Base64-encode bytes of AES encryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the Base64-encode bytes of AES encryption
     */
    public static byte[] encryptAES2Base64(final byte[] data,
                                           final byte[] key,
                                           final String transformation,
                                           final byte[] iv) {
        return base64Encode(encryptAES(data, key, transformation, iv));
    }

    /**
     * Return the hex string of AES encryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the hex string of AES encryption
     */
    public static String encryptAES2HexString(final byte[] data,
                                              final byte[] key,
                                              final String transformation,
                                              final byte[] iv) {
        return bytes2HexString(encryptAES(data, key, transformation, iv));
    }

    /**
     * Return the bytes of AES encryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of AES encryption
     */
    public static byte[] encryptAES(final byte[] data,
                                    final byte[] key,
                                    final String transformation,
                                    final byte[] iv) {
        return symmetricTemplate(data, key, "AES", transformation, iv, true);
    }

    /**
     * Return the bytes of AES decryption for Base64-encode bytes.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of AES decryption for Base64-encode bytes
     */
    public static byte[] decryptBase64AES(final byte[] data,
                                          final byte[] key,
                                          final String transformation,
                                          final byte[] iv) {
        return decryptAES(base64Decode(data), key, transformation, iv);
    }

    /**
     * Return the bytes of AES decryption for hex string.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of AES decryption for hex string
     */
    public static byte[] decryptHexStringAES(final String data,
                                             final byte[] key,
                                             final String transformation,
                                             final byte[] iv) {
        return decryptAES(hexString2Bytes(data), key, transformation, iv);
    }

    /**
     * Return the bytes of AES decryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param iv             The buffer with the IV. The contents of the
     *                       buffer are copied to protect against subsequent modification.
     * @return the bytes of AES decryption
     */
    public static byte[] decryptAES(final byte[] data,
                                    final byte[] key,
                                    final String transformation,
                                    final byte[] iv) {
        return symmetricTemplate(data, key, "AES", transformation, iv, false);
    }

    /**
     * Return the bytes of symmetric encryption or decryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param algorithm      The name of algorithm.
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
     * @param isEncrypt      True to encrypt, false otherwise.
     * @return the bytes of symmetric encryption or decryption
     */
    private static byte[] symmetricTemplate(final byte[] data,
                                            final byte[] key,
                                            final String algorithm,
                                            final String transformation,
                                            final byte[] iv,
                                            final boolean isEncrypt) {
        if (data == null || data.length == 0 || key == null || key.length == 0) return null;
        try {
            SecretKey secretKey;
            if ("DES".equals(algorithm)) {
                DESKeySpec desKey = new DESKeySpec(key);
                SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(algorithm);
                secretKey = keyFactory.generateSecret(desKey);
            } else {
                secretKey = new SecretKeySpec(key, algorithm);
            }
            Cipher cipher = Cipher.getInstance(transformation);
            if (iv == null || iv.length == 0) {
                cipher.init(isEncrypt ? Cipher.ENCRYPT_MODE : Cipher.DECRYPT_MODE, secretKey);
            } else {
                AlgorithmParameterSpec params = new IvParameterSpec(iv);
                cipher.init(isEncrypt ? Cipher.ENCRYPT_MODE : Cipher.DECRYPT_MODE, secretKey, params);
            }
            return cipher.doFinal(data);
        } catch (Throwable e) {
            e.printStackTrace();
            return null;
        }
    }

    // endregion

    // region RSA

    /**
     * Return the Base64-encode bytes of RSA encryption.
     *
     * @param data           The data.
     * @param publicKey      The public key.
     * @param keySize        The size of key, e.g. 1024, 2048...
     * @param transformation The name of the transformation, e.g., <i>RSA/CBC/PKCS1Padding</i>.
     * @return the Base64-encode bytes of RSA encryption
     */
    public static byte[] encryptRSA2Base64(final byte[] data,
                                           final byte[] publicKey,
                                           final int keySize,
                                           final String transformation) {
        return base64Encode(encryptRSA(data, publicKey, keySize, transformation));
    }

    /**
     * Return the hex string of RSA encryption.
     *
     * @param data           The data.
     * @param publicKey      The public key.
     * @param keySize        The size of key, e.g. 1024, 2048...
     * @param transformation The name of the transformation, e.g., <i>RSA/CBC/PKCS1Padding</i>.
     * @return the hex string of RSA encryption
     */
    public static String encryptRSA2HexString(final byte[] data,
                                              final byte[] publicKey,
                                              final int keySize,
                                              final String transformation) {
        return bytes2HexString(encryptRSA(data, publicKey, keySize, transformation));
    }

    /**
     * Return the bytes of RSA encryption.
     *
     * @param data           The data.
     * @param publicKey      The public key.
     * @param keySize        The size of key, e.g. 1024, 2048...
     * @param transformation The name of the transformation, e.g., <i>RSA/CBC/PKCS1Padding</i>.
     * @return the bytes of RSA encryption
     */
    public static byte[] encryptRSA(final byte[] data,
                                    final byte[] publicKey,
                                    final int keySize,
                                    final String transformation) {
        return rsaTemplate(data, publicKey, keySize, transformation, true);
    }

    /**
     * Return the bytes of RSA decryption for Base64-encode bytes.
     *
     * @param data           The data.
     * @param privateKey     The private key.
     * @param keySize        The size of key, e.g. 1024, 2048...
     * @param transformation The name of the transformation, e.g., <i>RSA/CBC/PKCS1Padding</i>.
     * @return the bytes of RSA decryption for Base64-encode bytes
     */
    public static byte[] decryptBase64RSA(final byte[] data,
                                          final byte[] privateKey,
                                          final int keySize,
                                          final String transformation) {
        return decryptRSA(base64Decode(data), privateKey, keySize, transformation);
    }

    /**
     * Return the bytes of RSA decryption for hex string.
     *
     * @param data           The data.
     * @param privateKey     The private key.
     * @param keySize        The size of key, e.g. 1024, 2048...
     * @param transformation The name of the transformation, e.g., <i>RSA/CBC/PKCS1Padding</i>.
     * @return the bytes of RSA decryption for hex string
     */
    public static byte[] decryptHexStringRSA(final String data,
                                             final byte[] privateKey,
                                             final int keySize,
                                             final String transformation) {
        return decryptRSA(hexString2Bytes(data), privateKey, keySize, transformation);
    }

    /**
     * Return the bytes of RSA decryption.
     *
     * @param data           The data.
     * @param privateKey     The private key.
     * @param keySize        The size of key, e.g. 1024, 2048...
     * @param transformation The name of the transformation, e.g., <i>RSA/CBC/PKCS1Padding</i>.
     * @return the bytes of RSA decryption
     */
    public static byte[] decryptRSA(final byte[] data,
                                    final byte[] privateKey,
                                    final int keySize,
                                    final String transformation) {
        return rsaTemplate(data, privateKey, keySize, transformation, false);
    }

    /**
     * Return the bytes of RSA encryption or decryption.
     *
     * @param data           The data.
     * @param key            The key.
     * @param keySize        The size of key, e.g. 1024, 2048...
     * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS1Padding</i>.
     * @param isEncrypt      True to encrypt, false otherwise.
     * @return the bytes of RSA encryption or decryption
     */
    private static byte[] rsaTemplate(final byte[] data,
                                      final byte[] key,
                                      final int keySize,
                                      final String transformation,
                                      final boolean isEncrypt) {
        if (data == null || data.length == 0 || key == null || key.length == 0) {
            return null;
        }
        try {
            Key rsaKey;
            KeyFactory keyFactory;
            if (Build.VERSION.SDK_INT < 28) {
                keyFactory = KeyFactory.getInstance("RSA", "BC");
            } else {
                keyFactory = KeyFactory.getInstance("RSA");
            }
            if (isEncrypt) {
                X509EncodedKeySpec keySpec = new X509EncodedKeySpec(key);
                rsaKey = keyFactory.generatePublic(keySpec);
            } else {
                PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(key);
                rsaKey = keyFactory.generatePrivate(keySpec);
            }
            if (rsaKey == null) return null;
            Cipher cipher = Cipher.getInstance(transformation);
            cipher.init(isEncrypt ? Cipher.ENCRYPT_MODE : Cipher.DECRYPT_MODE, rsaKey);
            int len = data.length;
            int maxLen = keySize / 8;
            if (isEncrypt) {
                String lowerTrans = transformation.toLowerCase();
                if (lowerTrans.endsWith("pkcs1padding")) {
                    maxLen -= 11;
                }
            }
            int count = len / maxLen;
            if (count > 0) {
                byte[] ret = new byte[0];
                byte[] buff = new byte[maxLen];
                int index = 0;
                for (int i = 0; i < count; i++) {
                    System.arraycopy(data, index, buff, 0, maxLen);
                    ret = joins(ret, cipher.doFinal(buff));
                    index += maxLen;
                }
                if (index != len) {
                    int restLen = len - index;
                    buff = new byte[restLen];
                    System.arraycopy(data, index, buff, 0, restLen);
                    ret = joins(ret, cipher.doFinal(buff));
                }
                return ret;
            } else {
                return cipher.doFinal(data);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * Return the bytes of RC4 encryption/decryption.
     *
     * @param data The data.
     * @param key  The key.
     */
    public static byte[] rc4(byte[] data, byte[] key) {
        if (data == null || data.length == 0 || key == null) return null;
        if (key.length < 1 || key.length > 256) {
            throw new IllegalArgumentException("key must be between 1 and 256 bytes");
        }
        final byte[] iS = new byte[256];
        final byte[] iK = new byte[256];
        int keyLen = key.length;
        for (int i = 0; i < 256; i++) {
            iS[i] = (byte) i;
            iK[i] = key[i % keyLen];
        }
        int j = 0;
        byte tmp;
        for (int i = 0; i < 256; i++) {
            j = (j + iS[i] + iK[i]) & 0xFF;
            tmp = iS[j];
            iS[j] = iS[i];
            iS[i] = tmp;
        }

        final byte[] ret = new byte[data.length];
        int i = 0, k, t;
        for (int counter = 0; counter < data.length; counter++) {
            i = (i + 1) & 0xFF;
            j = (j + iS[i]) & 0xFF;
            tmp = iS[j];
            iS[j] = iS[i];
            iS[i] = tmp;
            t = (iS[i] + iS[j]) & 0xFF;
            k = iS[t];
            ret[counter] = (byte) (data[counter] ^ k);
        }
        return ret;
    }

    // endregion

    // region inners

    public static byte[] hashTemplate(final byte[] data, final String algorithm) {
        if (data == null || data.length <= 0) return null;
        try {
            MessageDigest md = MessageDigest.getInstance(algorithm);
            md.update(data);
            return md.digest();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            return new byte[0];
        }
    }

    private static byte[] joins(final byte[] prefix, final byte[] suffix) {
        byte[] ret = new byte[prefix.length + suffix.length];
        System.arraycopy(prefix, 0, ret, 0, prefix.length);
        System.arraycopy(suffix, 0, ret, prefix.length, suffix.length);
        return ret;
    }

    /**
     * Return the bytes of hmac encryption.
     *
     * @param data      The data.
     * @param key       The key.
     * @param algorithm The name of hmac encryption.
     * @return the bytes of hmac encryption
     */
    private static byte[] hmacTemplate(final byte[] data,
                                       final byte[] key,
                                       final String algorithm) {
        if (data == null || data.length == 0 || key == null || key.length == 0) return null;
        try {
            SecretKeySpec secretKey = new SecretKeySpec(key, algorithm);
            Mac mac = Mac.getInstance(algorithm);
            mac.init(secretKey);
            return mac.doFinal(data);
        } catch (InvalidKeyException | NoSuchAlgorithmException e) {
            e.printStackTrace();
            return null;
        }
    }

    private EncryptUtils() {
        throw new UnsupportedOperationException("u can't initialize me!");
    }

    // endregion
}