DES加解密

偏执的太偏执、 2023-07-09 02:07 11阅读 0赞

## DES加解密工具类： ##

package com.prison.util;
    
    import java.security.InvalidKeyException;
    import java.security.NoSuchAlgorithmException;
    import java.security.spec.InvalidKeySpecException;
    
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.NoSuchPaddingException;
    import javax.crypto.SecretKey;
    import javax.crypto.SecretKeyFactory;
    import javax.crypto.spec.DESKeySpec;
    
    /**
     * DES加解密工具类
     * 
     */
    public class destil {
        private static final String DES_ALGORITHM = "DES";
        public static final String DES_KEY="lysoft_60985700";
    
        /**
         * DES加密
         * 
         * @param plainData 原始字符串
         * @param secretKey 加密密钥
         * @return 加密后的字符串
         * @throws Exception
         */
        public static String encryption(String plainData, String secretKey) throws Exception {
    
            Cipher cipher = null;
            try {
                cipher = Cipher.getInstance(DES_ALGORITHM);
                cipher.init(Cipher.ENCRYPT_MODE, generateKey(secretKey));
    
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            } catch (NoSuchPaddingException e) {
                e.printStackTrace();
            } catch (InvalidKeyException e) {
    
            }
    
            try {
                // 为了防止解密时报javax.crypto.IllegalBlockSizeException: Input length must
                // be multiple of 8 when decrypting with padded cipher异常，
                // 不能把加密后的字节数组直接转换成字符串
                byte[] buf = cipher.doFinal(plainData.getBytes());
    
                return Base64Utils.encode(buf);
    
            } catch (IllegalBlockSizeException e) {
                e.printStackTrace();
                throw new Exception("IllegalBlockSizeException", e);
            } catch (BadPaddingException e) {
                e.printStackTrace();
                throw new Exception("BadPaddingException", e);
            }
    
        }
    
    
        /**
         * DES解密
         * @param secretData 密码字符串
         * @param secretKey 解密密钥
         * @return 原始字符串
         * @throws Exception
         */
        public static String decryption(String secretData, String secretKey) throws Exception {
    
            Cipher cipher = null;
                cipher = Cipher.getInstance(DES_ALGORITHM);
                cipher.init(Cipher.DECRYPT_MODE, generateKey(secretKey));
    
    
    
                byte[] buf = cipher.doFinal(Base64Utils.decode(secretData.toCharArray()));
                return new String(buf);
    
        }
    
        /**
         * 获得秘密密钥
         * 
         * @param secretKey
         * @return
         * @throws NoSuchAlgorithmException
         * @throws InvalidKeySpecException
         * @throws InvalidKeyException
         */
        private static SecretKey generateKey(String secretKey)
                throws NoSuchAlgorithmException, InvalidKeySpecException, InvalidKeyException {
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES_ALGORITHM);
            DESKeySpec keySpec = new DESKeySpec(secretKey.getBytes());
            keyFactory.generateSecret(keySpec);
            return keyFactory.generateSecret(keySpec);
        }
    
        static private class Base64Utils {
    
            static private char[] alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
                    .toCharArray();
            static private byte[] codes = new byte[256];
    
            static {
                for (int i = 0; i < 256; i++)
                    codes[i] = -1;
                for (int i = 'A'; i <= 'Z'; i++)
                    codes[i] = (byte) (i - 'A');
                for (int i = 'a'; i <= 'z'; i++)
                    codes[i] = (byte) (26 + i - 'a');
                for (int i = '0'; i <= '9'; i++)
                    codes[i] = (byte) (52 + i - '0');
                codes['+'] = 62;
                codes['/'] = 63;
            }
    
            /**
             * 将原始数据编码为base64编码
             */
            static private String encode(byte[] data) {
                char[] out = new char[((data.length + 2) / 3) * 4];
                for (int i = 0, index = 0; i < data.length; i += 3, index += 4) {
                    boolean quad = false;
                    boolean trip = false;
                    int val = (0xFF & (int) data[i]);
                    val <<= 8;
                    if ((i + 1) < data.length) {
                        val |= (0xFF & (int) data[i + 1]);
                        trip = true;
                    }
                    val <<= 8;
                    if ((i + 2) < data.length) {
                        val |= (0xFF & (int) data[i + 2]);
                        quad = true;
                    }
                    out[index + 3] = alphabet[(quad ? (val & 0x3F) : 64)];
                    val >>= 6;
                    out[index + 2] = alphabet[(trip ? (val & 0x3F) : 64)];
                    val >>= 6;
                    out[index + 1] = alphabet[val & 0x3F];
                    val >>= 6;
                    out[index + 0] = alphabet[val & 0x3F];
                }
    
                return new String(out);
            }
    
            /**
             * 将base64编码的数据解码成原始数据
             */
            static private byte[] decode(char[] data) {
                int len = ((data.length + 3) / 4) * 3;
                if (data.length > 0 && data[data.length - 1] == '=')
                    --len;
                if (data.length > 1 && data[data.length - 2] == '=')
                    --len;
                byte[] out = new byte[len];
                int shift = 0;
                int accum = 0;
                int index = 0;
                for (int ix = 0; ix < data.length; ix++) {
                    int value = codes[data[ix] & 0xFF];
                    if (value >= 0) {
                        accum <<= 6;
                        shift += 6;
                        accum |= value;
                        if (shift >= 8) {
                            shift -= 8;
                            out[index++] = (byte) ((accum >> shift) & 0xff);
                        }
                    }
                }
    //            if (index != out.length){
    //            	 throw new Error("miscalculated data length!");
    //            }
                   
                return out;
            }
        }
    }

## DES加密： ##

destil.encryption(password, destil.DES_KEY);

## DES解密： ##

destil.decryption(uList.get(i).getPassword(), destil.DES_KEY)