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CRYPTO

FGJ: Create:2024/01/30 Update: (2024-10-24)

  • Intro #

    常见的 对称加密 算法主要有 DES、3DES、 AES 等，常见的 非对称算法 主要有 RSA、DSA、ECC，散列算法 主要有 SHA-1、 MD5 等。 代码实现参考

  • Key #

    • 生成自定义key #

      使用ascii生成可以的方法如下：

      public static byte[] getRandomKey(){
    int len = 16; // 128 ->16  256->32
    byte[] keys = new byte[len];
    Random rdom = new Random();
    for (int i = 0; i < len; i++) {
        keys[i] = (byte) (rdom.nextInt(126-34) +34);
    }
    return keys;
}
// kZZ`MbMLbp5sc7Y'
// U2yT4Q)2Ss+Li=Y)
// "OAKJH5kKKLq?g'p
// h&GKS.gAG,H_@et%
// .]?]_8ECB[Z'gYn)
// <mJ\J_PlLE][_uI9
// 2j=HC,#Au}VDE\P:
// 27Fqc/j6LODd<.8O
// Gtt17Q\IyFrNtthk
// 4q>?A{b|mo@kqM2Q

    • 使用SecretKeyFactory构造 #

      private static SecretKey getKey(String key) throws Exception {
    DESKeySpec dks = new DESKeySpec(key.getBytes("utf-8"));
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
    return keyFactory.generateSecret(dks);
}
// split .can direct use
private static SecretKey getKey(byte[] key){
    return new SecretKeySpec(key, "AES");
}

    • 使用KeyGenerator生成全新的 #

      public static byte[] getRandomKey() throws Exception {
    KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
    SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG", "SUN");
    secureRandom.setSeed(("AES/CBC/PKCS7Padding" + "EVERY-seed").getBytes());
    keyGenerator.init(256, secureRandom); //要生成多少位，只需要修改这里即可128, 192或256
    SecretKey originalKey = keyGenerator.generateKey();
    return originalKey.getEncoded(); // byte[32]
}

    • Reference

  • Test #

    • DES #

      @Test
public void testDES(){

    String key = "U2yT4Q)2Ss+Li=Y)";
    String iv  = "2j=HC,#Au}VDE\\P:";
    iv  = "2=H,#Au}"; //des 8 byte
    String data = "hello world from 加密";

    String encrypt = DES.encrypt(data, key.getBytes(), iv.getBytes());
    System.out.println(encrypt);
    String decrypt = DES.decrypt(encrypt, key.getBytes(), iv.getBytes());
    System.out.println(decrypt);

}

    • AES #

      @Test
public void testAES(){
    String key = "U2yT4Q)2Ss+Li=Y)";
    String iv  = "2j=HC,#Au}VDE\\P:";
    //iv  = "2=H,#Au}"; //des 8 byte
    String data = "hello world from 加密";

    String encrypt = AES.encrypt(data, key.getBytes(), iv.getBytes());
    System.out.println(encrypt);
    String decrypt = AES.decrypt(encrypt, key.getBytes(), iv.getBytes());
    System.out.println(decrypt);
}

  • Reference #

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