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  • Android--DES加密

    Base64.java

    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.io.OutputStream;
    
    public class Base64 {
        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;
            }
        }
    
    }

    DES.java

    package cn.crane.game.puzzle.utils.security;
    import javax.crypto.Cipher;
    import javax.crypto.spec.IvParameterSpec;
    import javax.crypto.spec.SecretKeySpec;
    
    public class DES {
        private static byte[] iv = { 1, 2, 3, 4, 5, 6, 7, 8 };
    
        /**
         * 加密
         * 
         * @param encryptString
         * @param encryptKey
         * @return
         * @throws Exception
         */
        public static String encryptDES(String encryptString, String encryptKey) {
            // IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]);
            try {
                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 Base64.encode(encryptedData);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return "";
        }
    
        /**
         * 解密
         * 
         * @param decryptString
         * @param decryptKey
         * @return
         * @throws Exception
         */
        public static String decryptDES(String decryptString, String decryptKey) {
            try {
                byte[] byteMi = Base64.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);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return "";
    
        }
    }
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  • 原文地址:https://www.cnblogs.com/crane13/p/3704442.html
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