private final int AES_KEY_LENGTH = 16;//密鑰長(zhǎng)度16字節(jié)，128位
    private final String AES_ALGORITHM = "AES";//算法名字
    private final String AES_TRANSFORMATION = "AES/CBC/PKCS5Padding";//算法/模式/填充
    private final String AES_IV = "0112030445060709";//使用CBC模式，需要一個(gè)向量iv，可增加加密算法的強(qiáng)度
    private final String AES_STRING = "abcdefghijklmnopqrstuvwxyzABCDEFGHIGKLOP";
    private final Charset UTF_8 = Charset.forName("UTF-8");//編碼格式
    /**
     * 使用AES加密
     *
     * @param aesKey AES Key
     * @param data   被加密的數(shù)據(jù)
     * @return AES加密后的數(shù)據(jù)
     */
    private byte[] encodeAES(byte[] aesKey, String data) {
        if (aesKey == null || aesKey.length != AES_KEY_LENGTH) {
            return null;
        }
        SecretKeySpec keySpec = new SecretKeySpec(aesKey, AES_ALGORITHM);
        try {
            Cipher cipher = Cipher.getInstance(AES_TRANSFORMATION);
            IvParameterSpec iv = new IvParameterSpec(AES_IV.getBytes(UTF_8));
            cipher.init(Cipher.ENCRYPT_MODE, keySpec, iv);
            return cipher.doFinal(data.getBytes(UTF_8));
        } catch (Exception e) {
            Log.d(TAG, e.getMessage(), e);
        }
        return null;
    }
    /**
     * 使用AES解密
     *
     * @param aesKey AES Key
     * @param data   被解密的數(shù)據(jù)
     * @return AES解密后的數(shù)據(jù)
     */
    private String decodeAES(byte[] aesKey, byte[] data) {
        if (aesKey == null || aesKey.length != AES_KEY_LENGTH) {
            return null;
        }
        SecretKeySpec keySpec = new SecretKeySpec(aesKey, AES_ALGORITHM);
        try {
            Cipher cipher = Cipher.getInstance(AES_TRANSFORMATION);
            IvParameterSpec iv = new IvParameterSpec(AES_IV.getBytes(UTF_8));
            cipher.init(Cipher.DECRYPT_MODE, keySpec, iv);
            return new String(cipher.doFinal(data), UTF_8);
        } catch (Exception e) {
            Log.d(TAG, e.getMessage(), e);
        }
        return null;
    }
    private int getRandom(int count) {
        return (int) Math.round(Math.random() * (count));
    }
    /**
     * 生成AES key
     *
     * @return AES key
     */
    private String initAESKey() {
        StringBuilder sb = new StringBuilder();
        int len = AES_STRING.length();
        for (int i = 0; i < AES_KEY_LENGTH; i++) {
            sb.append(AES_STRING.charAt(getRandom(len - 1)));
        }
        return sb.toString();
    }

    /**
     * 對(duì)數(shù)據(jù)進(jìn)行Base64編碼，使用的是{@link android.util.Base64}，而且flags需要使用 {@link android.util.Base64#URL_SAFE,android.util#Base64.NO_PADDING,android.util.Base64#NO_WRAP}。
     *
     * @param input 來源數(shù)據(jù)
     * @return Base64編碼的數(shù)據(jù)
     */
    private String encodeBase64(byte[] input) {
        return new String(Base64.encode(input, Base64.URL_SAFE | Base64.NO_PADDING | Base64.NO_WRAP), UTF_8);
    }

    /**
     * 對(duì)數(shù)據(jù)進(jìn)行Base64解碼，使用的是{@link android.util.Base64}，而且flags需要使用 {@link android.util.Base64#URL_SAFE,android.util.Base64#NO_WRAP}，主要是為了和Base64加密對(duì)應(yīng)。
     *
     * @param str 需要解碼的數(shù)據(jù)
     * @return Base64解碼后的數(shù)據(jù)
     */
    private byte[] decodeBase64(String str) {
        return Base64.decode(str.getBytes(UTF_8), Base64.URL_SAFE | Base64.DEFAULT);
    }

    private final String RSA_PUB_KEY = "服務(wù)端給的公鑰";
    private final String RSA_TRANSFORMATION = "RSA/ECB/PKCS1Padding";
    /**
     * 公鑰加密
     *
     * @param data           要加密的數(shù)據(jù)
     * @param key            公鑰
     * @param transformation 算法/模式/填充
     * @return 加密后的數(shù)據(jù)
     */
    public byte[] encryptByPublicKey(byte[] data, String key, String transformation)
            throws GeneralSecurityException {
        byte[] keyBytes = Base64.decode(key.getBytes(UTF_8), Base64.NO_WRAP);
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PublicKey pubKey = keyFactory.generatePublic(keySpec);
        Cipher cipher = Cipher.getInstance(transformation);
        cipher.init(Cipher.ENCRYPT_MODE, pubKey);
        return cipher.doFinal(data);
    }