Java中常见加密算法

1. MD5Utils

    package com.jzx.encrypted_utils;
 
    import java.security.MessageDigest;
    
    public class MD5Utils {
    
        private static final String hexDigIts[] = {"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};
        //之所以不是char数组是为了防止拼接的时候进行加法运算
        /**
         * MD5加密
         * @param origin 原始字符串
         * @param charsetname 编码
         * @return
         */
        public static String MD5Encode(String origin, String charsetname){
            String resultString = null;
            try{
                resultString = new String(origin);
                MessageDigest md = MessageDigest.getInstance("MD5");
                if(null == charsetname || "".equals(charsetname)){    //字符集为空
                    resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
                }else{                                                //字符集非空
                    resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
                }
            }catch (Exception e){
            }
            return resultString;
        }
    
    
        public static String byteArrayToHexString(byte b[]){
            StringBuffer resultSb = new StringBuffer();
            for(int i = 0; i < b.length; i++){
                resultSb.append(byteToHexString(b[i])); //将每个字符都转化为十六进制数
            }
            return resultSb.toString();
        }
    
        public static String byteToHexString(byte b){
            int n = b;                  //转换成对应的ASCII值
            if(n < 0){
                n += 256;
            }
            int d1 = n / 16;            //转换成对应十六进制数"d1d2"
            int d2 = n % 16;
            return hexDigIts[d1] + hexDigIts[d2];
            //索引正好对应相应的单字符串（0对应字符"0"），若是char数组的话会进行加法运算
        }
    
    }

2. Base64

    package com.jzx.encrypted_utils;
 
        import org.apache.commons.codec.binary.Base64;
        import java.io.UnsupportedEncodingException;
        
        public class Base64Util {
        
            // 字符串编码
            private static final String UTF_8 = "UTF-8";
        
            /**
             * 加密字符串
             * @param inputData
             * @return
             */
            public static String encodeData(String inputData) {
                try {
                    if (null == inputData) {
                        return null;
                    }
                    return new String(Base64.decodeBase64(inputData.getBytes(UTF_8)), UTF_8);
                } catch (UnsupportedEncodingException e) {
                }
                return null;
            }
        
            /**
             * 解密加密后的字符串
             * @param inputData
             * @return
             */
            public static String decodeData(String inputData) {
                try {
                    if (null == inputData) {
                        return null;
                    }
                    return new String(Base64.encodeBase64(inputData.getBytes(UTF_8)), UTF_8);
                } catch (UnsupportedEncodingException e) {
                }
                return null;
            }
        }

3. BcryptCipher

    package com.jzx.encrypted_utils;
 
        import java.util.HashMap;
        import java.util.Map;
        
        import org.apache.commons.lang3.StringUtils;
        import org.mindrot.bcrypt.BCrypt;
        
        public class BcryptCipher {
            // generate salt seed
            private static final int SALT_SEED = 12;
            // the head fo salt
            private static final String SALT_STARTSWITH = "$2a$12";
        
            public static final String SALT_KEY = "salt";
        
            public static final String CIPHER_KEY = "cipher";
        
            /**
             * Bcrypt encryption algorithm method
             * @param encryptSource
             *                  need to encrypt the string
             * @return Map , two values in Map , salt and cipher
             */
            public static Map<String, String> Bcrypt(final String encryptSource) {
                String salt  = BCrypt.gensalt(SALT_SEED);
                Map<String, String> bcryptResult = Bcrypt(salt, encryptSource);
                return bcryptResult;
            }
            /**
             *
             * @param salt encrypt salt, Must conform to the rules
             * @param encryptSource
             * @return
             */
            public static Map<String, String> Bcrypt(final String salt, final String encryptSource) {
                if (StringUtils.isBlank(encryptSource)) {
                    throw new RuntimeException("Bcrypt encrypt input params can not be empty");
                }
        
                if (StringUtils.isBlank(salt) || salt.length() != 29) {
                    throw new RuntimeException("Salt can't be empty and length must be to 29");
                }
                if (!salt.startsWith(SALT_STARTSWITH)) {
                    throw new RuntimeException("Invalid salt version, salt version is $2a$12");
                }
        
                String cipher = BCrypt.hashpw(encryptSource, salt);
                Map<String, String> bcryptResult = new HashMap<String, String>();
                bcryptResult.put(SALT_KEY, salt);
                bcryptResult.put(CIPHER_KEY, cipher);
                return bcryptResult;
            }
        
        }

测试：

    public static void main(String[] args) {
 
            String string = "我是一句话";
            Map<String, String> bcrypt = BcryptCipher.Bcrypt(string);
            System.out.println(bcrypt.keySet());        //[cipher, salt]
        
            System.out.println(bcrypt.get("cipher"));   //获取cipher值
            //$2a$12$ylb92Z84gqlrSfzIztlCV.dK0xNbw.pOv3UwXXA76llOsNRTJsE
            System.out.println(bcrypt.get("salt"));     //获取salt值
            //$2a$12$ylb92Z84gqlrSfzIztlCV.
        
            Map<String, String> bcrypt2 = BcryptCipher.Bcrypt(bcrypt.get("salt"),string);
            System.out.println(bcrypt2.get("SALT_KEY"));     //null
            System.out.println(bcrypt2.get("CIPHER_KEY"));   //null
        }