DES加密解密

加解密方法：

public class DESPlus {
    private static String strDefaultKey = "default";
    private Cipher encryptCipher;
    private Cipher decryptCipher;

    public static String byteArr2HexStr(byte[] arrB) throws Exception {
        int iLen = arrB.length;
        StringBuffer sb = new StringBuffer(iLen * 2);
        for(int i = 0; i < iLen; ++i) {
            int intTmp;
            for(intTmp = arrB[i]; intTmp < 0; intTmp += 256) {
            }
            if (intTmp < 16) {
                sb.append("0");
            }
            sb.append(Integer.toString(intTmp, 16));
        }
        return sb.toString();
    }

    public static byte[] hexStr2ByteArr(String strIn) throws Exception {
        byte[] arrB = strIn.getBytes();
        int iLen = arrB.length;
        byte[] arrOut = new byte[iLen / 2];

        for(int i = 0; i < iLen; i += 2) {
            String strTmp = new String(arrB, i, 2);
            arrOut[i / 2] = (byte)Integer.parseInt(strTmp, 16);
        }

        return arrOut;
    }

    public DESPlus() throws Exception {
        this(strDefaultKey);
    }

    public DESPlus(String strKey) throws Exception {
        this.encryptCipher = null;
        this.decryptCipher = null;
        Security.addProvider(new SunJCE());
        Key key = this.getKey(strKey.getBytes());
        this.encryptCipher = Cipher.getInstance("DES/ECB/NoPadding");
        this.encryptCipher.init(1, key);
        this.decryptCipher = Cipher.getInstance("DES/ECB/NoPadding");
        this.decryptCipher.init(2, key);
    }

    public byte[] encrypt(byte[] arrB) throws Exception {
        return this.encryptCipher.doFinal(arrB);
    }

    public String encrypt(String strIn) throws Exception {
        while (strIn.getBytes().length % 8 != 0) {
            System.out.println("加密需要是8的倍数：+1空格");
            strIn += " ";
        }
        return byteArr2HexStr(this.encrypt(strIn.getBytes()));
    }

    public byte[] decrypt(byte[] arrB) throws Exception {
        return this.decryptCipher.doFinal(arrB);
    }

    public String decrypt(String strIn) throws Exception {
        return new String(this.decrypt(hexStr2ByteArr(strIn)));
    }

    private Key getKey(byte[] arrBTmp) throws Exception {
        byte[] arrB = new byte[8];
        for(int i = 0; i < arrBTmp.length && i < arrB.length; ++i) {
            arrB[i] = arrBTmp[i];
        }
        Key key = new SecretKeySpec(arrB, "DES");
        return key;
    }
}

标签：Exception,加密,String,DES,解密,throws,byte,public,arrB
来源： https://blog.csdn.net/jockha/article/details/122580989