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  • android----Java DES加密算法工具类

    DESUtil类

    public class DESUtil {
    
       
    
        private static byte[] iv = {0x12, 0x34, 0x56, 0x78, (byte) 0x90, (byte) 0xAB, (byte) 0xCD, (byte) 0xEF};
        //-----------------加密-----------------
        public static String encryptDES(String encryptString, String encryptKey) throws Exception {
    //        IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]);
            IvParameterSpec zeroIv = new IvParameterSpec(iv);
            SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "DES");
            Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
            byte[] encryptedData = cipher.doFinal(encryptString.getBytes());
            return Base64DES.encode(encryptedData);
        }
    //------------------解密---------------------
    public static String decryptDES(String decryptString, String decryptKey) throws Exception { byte[] byteMi = new Base64DES().decode(decryptString); IvParameterSpec zeroIv = new IvParameterSpec(iv); // IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]); SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "DES"); Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding"); cipher.init(Cipher.DECRYPT_MODE, key, zeroIv); byte decryptedData[] = cipher.doFinal(byteMi); return new String(decryptedData); } }

    上面类中用到的Base64DES工具类

    public class Base64DES {
        private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
        /**
         * data[]进行编码
         * @param data
         * @return
         */
        public static String encode(byte[] data) {
            int start = 0;
            int len = data.length;
            StringBuffer buf = new StringBuffer(data.length * 3 / 2);
    
            int end = len - 3;
            int i = start;
            int n = 0;
    
            while (i <= end) {
                int d = ((((int) data[i]) & 0x0ff) << 16)
                        | ((((int) data[i + 1]) & 0x0ff) << 8)
                        | (((int) data[i + 2]) & 0x0ff);
    
                buf.append(legalChars[(d >> 18) & 63]);
                buf.append(legalChars[(d >> 12) & 63]);
                buf.append(legalChars[(d >> 6) & 63]);
                buf.append(legalChars[d & 63]);
    
                i += 3;
    
                if (n++ >= 14) {
                    n = 0;
                    buf.append(" ");
                }
            }
    
            if (i == start + len - 2) {
                int d = ((((int) data[i]) & 0x0ff) << 16)
                        | ((((int) data[i + 1]) & 255) << 8);
    
                buf.append(legalChars[(d >> 18) & 63]);
                buf.append(legalChars[(d >> 12) & 63]);
                buf.append(legalChars[(d >> 6) & 63]);
                buf.append("=");
            } else if (i == start + len - 1) {
                int d = (((int) data[i]) & 0x0ff) << 16;
    
                buf.append(legalChars[(d >> 18) & 63]);
                buf.append(legalChars[(d >> 12) & 63]);
                buf.append("==");
            }
    
            return buf.toString();
        }
    
        private static int decode(char c) {
            if (c >= 'A' && c <= 'Z')
                return ((int) c) - 65;
            else if (c >= 'a' && c <= 'z')
                return ((int) c) - 97 + 26;
            else if (c >= '0' && c <= '9')
                return ((int) c) - 48 + 26 + 26;
            else
                switch (c) {
                    case '+':
                        return 62;
                    case '/':
                        return 63;
                    case '=':
                        return 0;
                    default:
                        throw new RuntimeException("unexpected code: " + c);
                }
        }
    
        /**
         * Decodes the given Base64 encoded String to a new byte array. The byte
         * array holding the decoded data is returned.
         */
    
        public static byte[] decode(String s) {
    
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            try {
                decode(s, bos);
            } catch (IOException e) {
                throw new RuntimeException();
            }
            byte[] decodedBytes = bos.toByteArray();
            try {
                bos.close();
                bos = null;
            } catch (IOException ex) {
                System.err.println("Error while decoding BASE64: " + ex.toString());
            }
            return decodedBytes;
        }
    
        private static void decode(String s, OutputStream os) throws IOException {
            int i = 0;
    
            int len = s.length();
    
            while (true) {
                while (i < len && s.charAt(i) <= ' ')
                    i++;
    
                if (i == len)
                    break;
    
                int tri = (decode(s.charAt(i)) << 18)
                        + (decode(s.charAt(i + 1)) << 12)
                        + (decode(s.charAt(i + 2)) << 6)
                        + (decode(s.charAt(i + 3)));
    
                os.write((tri >> 16) & 255);
                if (s.charAt(i + 2) == '=')
                    break;
                os.write((tri >> 8) & 255);
                if (s.charAt(i + 3) == '=')
                    break;
                os.write(tri & 255);
    
                i += 4;
            }
        }
    }
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  • 原文地址:https://www.cnblogs.com/819158327fan/p/5060618.html
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