java Aes256 加密算法的实现

叁歲伎倆 2022-08-06 07:09 27阅读 0赞

如果希望进行AES256位的加密解密，需要事先从java官网下载 local\_policy.jar与US\_export\_policy.jar替换%JAVA\_HOME%/jre/lib/security的两个policy文件，local\_policy.jar与US\_export\_policy .jar。 主要是为了突破AES算法只能支持到128位的限制。如果未替换，可能会得到如下错误： \*

java.security.InvalidKeyException: Illegal key
     
     
     
    package com.jlins;
     
    import java.io.UnsupportedEncodingException;
     
    import javax.crypto.Cipher;
     
    import javax.crypto.spec.IvParameterSpec;
     
    import javax.crypto.spec.SecretKeySpec;
     
    import com.jlins.util.Hex;
     
    /**
     
    * java Aes256 加密
     
    *
     
    * @author jlins
     
    *
     
    */
     
    public class Aes256Encryptor {
     
    // 说明 key 需要大家自己去设定加密解密的key，key牵涉到安全信息,所以这里无法公布
     
        private static final byte[] key = {};
     
        private static final String transform = "AES/CBC/NoPadding";
     
        private static final String algorithm = "AES";
     
        private static final SecretKeySpec keySpec = new SecretKeySpec(key, algorithm);
     
        public static void main(String[] args) throws Exception {
     
             String pwds[] = { "123", "0123456789012345", "01234567890123456", "123", "123", "0123456789012345678",
     
                                "012345678901234567890123456789", "b", "0123456789012345", "01234567890123456", "012345678901234567" };
     
            String ivss[] = { "test", "test", "test", "test0123456789012", "test01234567890123", "test", "test", "a",
     
                            "test", "test", "test" };
     
            String rr[] = new String[ivss.length];
     
             for (int i = 0; i < ivss.length; i++) {
     
                String en = encrypt(pwds[i], ivss[i]);
     
                String decy = decrypt(en, ivss[i]);
     
                rr[i] = "[" + ivss[i] + "],[" + decy + "]-->[" + en + "]";
     
                System.out.println(rr[i]);
     
               }
     
               System.out.println("---------");
     
               for (int i = 0; i < rr.length; i++) {
     
                   System.out.println(rr[i]);
     
                }
     
    }
     
    /**
     
    */
     
    public static String decrypt(String pHexText, String pIv) throws Exception {
     
            Cipher cipher = Cipher.getInstance(transform);
     
            byte[] encryptedBytes = Hex.decode(pHexText);
     
            byte[] iv = createIV(pIv);
     
            cipher.init(Cipher.DECRYPT_MODE, keySpec, new IvParameterSpec(iv));
     
            byte[] decryptedBytes = cipher.doFinal(encryptedBytes);
     
            System.arraycopy(decryptedBytes, 0, encryptedBytes, 0, encryptedBytes.length);
     
            String result = new String(encryptedBytes);
     
            return result.trim();
     
    }
     
    /**
     
    */
     
    public static String encrypt(String pData, String pIv) throws Exception {
     
             Cipher cipher = Cipher.getInstance(transform);
     
             byte[] iv = createIV(pIv);
     
             cipher.init(Cipher.ENCRYPT_MODE, keySpec, new IvParameterSpec(iv));
     
             byte[] output = cipher.doFinal(paddingData(pData));
     
             byte[] encryptedContent = new byte[output.length];
     
             System.arraycopy(output, 0, encryptedContent, 0, encryptedContent.length);
     
             String result = new String(Hex.encode(encryptedContent)).toUpperCase();
     
             return result;
     
    }
     
    /**
     
    * 补齐的16位的整数倍
     
    *
     
    * @param pData
     
    * @return
     
    */
     
    private static byte[] paddingData(String pData) {
     
           byte[] bytes = pData.getBytes();
     
           int length = bytes.length / 16;
     
           if (length * 16 < bytes.length) {
     
              length++;
     
            }
     
           byte[] result = new byte[length * 16];
     
           System.arraycopy(bytes, 0, result, 0, bytes.length);
     
           for (int i = bytes.length; i < result.length; i++) {
     
             result[i] = 0x00;
     
            }
     
            return result;
     
            }
     
    /**
     
    * 初始化向量到16位
     
    * */
     
           private static byte[] createIV(String pIv) throws UnsupportedEncodingException {
     
           byte[] bytes = pIv.getBytes("US-ASCII");
     
           int length = bytes.length / 16;
     
           if (length * 16 < bytes.length) {
     
           length++;
     
           }
     
           byte[] result = new byte[16];
     
           System.arraycopy(bytes, 0, result, 0, bytes.length > 16 ? 16 : bytes.length);
     
           for (int i = bytes.length; i < result.length; i++) {
     
           result[i] = 0x00;
     
          }
     
          return result;
     
    }
     
    }

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