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C#常用的加密算法:MD5、Base64、SHA1、SHA256、HmacSHA256、DES、AES、RSA

程序员文章站 2024-03-20 10:29:04
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简介

本文主vb.net教程要讲c#教程解一下C#常用的python基础教程那些加密java基础教程算法,包括MD5、Base64、SHA1、SHA256、HmacSHA256、DES、AES、RSA加密sql教程等,有需要的朋友可以参考下

需要引用的类

using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

还需要安装 BouncyCastle
在菜单栏找到 工具 —> NuGet 包管理器 —> 管理解决方案的NuGet程序包 —> 浏览 —> 搜索 “BouncyCastle” —> 安装
C#常用的加密算法:MD5、Base64、SHA1、SHA256、HmacSHA256、DES、AES、RSA
我自己定义的公共字段;有需要的朋友可以自行定义

        private static CspParameters Param;

        /// <summary>
        /// SK(Secret Access Key):与访问**ID结合使用的**,对请求进行加密签名,可标识发送方,并防止请求被修改
        /// </summary>
        public static string _appSecret = ConfigurationManager.AppSettings["appSecret"].ToString();

        /// <summary>
        /// AK(Access Key ID):访问**ID。与私有访问**关联的唯一标识符;访问**ID和私有访问**一起使用,对请求进行加密签名
        /// </summary>
        public static string _appKey = ConfigurationManager.AppSettings["appKey"].ToString();

        /// <summary>
        /// DES**
        /// </summary>
        private static byte[] _KEY = new byte[] { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 };

        /// <summary>
        /// DES向量
        /// </summary>
        private static byte[] _IV = new byte[] { 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01 };

        /// <summary>
        /// RSA加密/解密的默认公钥
        /// </summary>
        private static string _publicKey = @"<RSAKeyValue><Modulus>5m9m14XH3oqLJ8bNGw9e4rGpXpcktv9MSkHSVFVMjHbfv+SJ5v0ubqQxa5YjLN4vc49z7SVju8s0X4gZ6AzZTn06jzWOgyPRV54Q4I0DCYadWW4Ze3e+BOtwgVU1Og3qHKn8vygoj40J6U85Z/PTJu3hN1m75Zr195ju7g9v4Hk=</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";

        /// <summary>
        /// RSA解密/加密的默认私钥
        /// </summary>
        private static string _privateKey = @"<RSAKeyValue><Modulus>5m9m14XH3oqLJ8bNGw9e4rGpXpcktv9MSkHSVFVMjHbfv+SJ5v0ubqQxa5YjLN4vc49z7SVju8s0X4gZ6AzZTn06jzWOgyPRV54Q4I0DCYadWW4Ze3e+BOtwgVU1Og3qHKn8vygoj40J6U85Z/PTJu3hN1m75Zr195ju7g9v4Hk=</Modulus><Exponent>AQAB</Exponent><P>/hf2dnK7rNfl3lbqghWcpFdu778hUpIEBixCDL5WiBtpkZdpSw90aERmHJYaW2RGvGRi6zSftLh00KHsPcNUMw==</P><Q>6Cn/jOLrPapDTEp1Fkq+uz++1Do0eeX7HYqi9rY29CqShzCeI7LEYOoSwYuAJ3xA/DuCdQENPSoJ9KFbO4Wsow==</Q><DP>ga1rHIJro8e/yhxjrKYo/nqc5ICQGhrpMNlPkD9n3CjZVPOISkWF7FzUHEzDANeJfkZhcZa21z24aG3rKo5Qnw==</DP><DQ>MNGsCB8rYlMsRZ2ek2pyQwO7h/sZT8y5ilO9wu08Dwnot/7UMiOEQfDWstY3w5XQQHnvC9WFyCfP4h4QBissyw==</DQ><InverseQ>EG02S7SADhH1EVT9DD0Z62Y0uY7gIYvxX/uq+IzKSCwB8M2G7Qv9xgZQaQlLpCaeKbux3Y59hHM+KpamGL19Kg==</InverseQ><D>vmaYHEbPAgOJvaEXQl+t8DQKFT1fudEysTy31LTyXjGu6XiltXXHUuZaa2IPyHgBz0Nd7znwsW/S44iql0Fen1kzKioEL3svANui63O3o5xdDeExVM6zOf1wUUh/oldovPweChyoAdMtUzgvCbJk1sYDJf++Nr0FeNW1RB1XG30=</D></RSAKeyValue>";

        /// <summary>
        /// 8位加***
        /// </summary>
        private static string keys = "olikjhgb";

        /// <summary>
        /// 16位的加密秘钥
        /// </summary>
        private static string Key = "[email protected]_Lq";

        /// <summary>
        /// 16位以上的默认向量
        /// </summary>
        private static string vector = "*[email protected]";

一、MD5加密

  • MD5加密是最常见的加密方式,因为MD5是不可逆的,所以很多系统的密码都是用MD5加密保存的。
  • 虽说MD5加密不可逆,但是我们可以对明文再次加密,进行两次加密的密文进行对比
        #region MD5加密解密
        /// <summary>
        /// 16位MD5加密
        /// </summary>
        /// <param name="laws">需要加密的明文字符串</param>
        /// <returns></returns>
        public static string MD5Encrypt16(string laws)
        {
            var md5 = new MD5CryptoServiceProvider();
            string cipherText = BitConverter.ToString(md5.ComputeHash(Encoding.Default.GetBytes(laws)), 4, 8);
            cipherText = cipherText.Replace("-", "");
            return cipherText;
        }

        /// <summary>
        /// 32位MD5加密
        /// </summary>
        /// <param name="laws">需要加密的明文字符串</param>
        /// <returns>32位MD5加密密文字符串</returns>
        public static string MD5Encrypt32(string laws)
        {
            string plainText = laws;
            string rule = "";
            MD5 md5 = MD5.Create(); //实例化一个md5对像
                                    // 加密后是一个字节类型的数组,这里要注意编码UTF8/Unicode等的选择 
            byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(plainText));
            // 通过使用循环,将字节类型的数组转换为字符串,此字符串是常规字符格式化所得
            for (int i = 0; i < s.Length; i++)
            {
                // 将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母,如果使用大写(X)则格式后的字符是大写字符 
                rule = rule + s[i].ToString("x2");
            }
            return rule;
        }

        /// <summary>
        /// 64位MD5加密
        /// </summary>
        /// <param name="laws">需要加密的明文字符串</param>
        /// <returns>64位MD5加密密文字符串</returns>
        public static string MD5Encrypt64(string laws)
        {
            string rule = laws;
            MD5 md5 = MD5.Create(); //实例化一个md5对像
            // 加密后是一个字节类型的数组,这里要注意编码UTF8/Unicode等的选择 
            byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(rule));
            return Convert.ToBase64String(s);
        }

        /// <summary>
        /// 对字符串进MD5加密
        /// </summary>
        /// <param name="sourceStr">源类型</param>
        /// <returns>加密后字符串</returns>
        public static string Md5Encrypt(string sourceStr)
        {
            MD5 md5 = new MD5CryptoServiceProvider();
            //将要加密的字符串转换成字节数组
            byte[] palindata = Encoding.Default.GetBytes(sourceStr);
            //通过字节数组进行加密
            byte[] encryptdata = md5.ComputeHash(palindata);
            //将加密后的字节数组转换成字符串
            string returnData = Convert.ToBase64String(encryptdata);
            return returnData;
        }

        /// <summary>
        ///  Md5**加密
        /// </summary>
        /// <param name="pToEncrypt">要加密的string字符串</param>
        /// <returns></returns>
        public static string Md5Encrypt_Key(string pToEncrypt)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);
            des.Key = Encoding.ASCII.GetBytes(keys);
            des.IV = Encoding.ASCII.GetBytes(keys);
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            var s = ret.ToString();
            return s;
        }

        /// <summary>
        ///  Md5解密
        /// </summary>
        /// <param name="pToDecrypt">解密string</param>
        /// <returns></returns>
        public static string Md5Decrypt(string pToDecrypt)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = new byte[pToDecrypt.Length / 2];
            for (int x = 0; x < pToDecrypt.Length / 2; x++)
            {
                int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
                inputByteArray[x] = (byte)i;
            }
            des.Key = Encoding.ASCII.GetBytes(_appSecret);
            des.IV = Encoding.ASCII.GetBytes(_appSecret);
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            return Encoding.Default.GetString(ms.ToArray());
        }

        /// <summary>
        /// MD5流加密
        /// </summary>
        /// <param name="inputStream">输入流</param>
        /// <returns></returns>
        public static string GenerateMD5(Stream inputStream)
        {
            using (MD5 mi = MD5.Create())
            {
                //开始加密
                byte[] newBuffer = mi.ComputeHash(inputStream);
                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < newBuffer.Length; i++)
                {
                    sb.Append(newBuffer[i].ToString("x2"));
                }
                return sb.ToString();
            }
        }
#endregion

二、Base64加码解码

  • 严格来说,Base64是一种编码,而不是加密,通常Base64编码后字符串会用于传输数据。不过也正是因为Base64编码后字符串具有不可读性;也有人当做加密算法来使用。
        #region Base64加码解码
        /// <summary>
        /// Base64编码,采用utf8编码
        /// </summary>
        /// <param name="strPath">待编码的明文</param>
        /// <returns>Base64编码后的字符串</returns>
        public static string Base64Encrypt(string strPath)
        {
            string returnData;
            Encoding encode = Encoding.UTF8;
            byte[] bytedata = encode.GetBytes(strPath);
            try
            {
                returnData = Convert.ToBase64String(bytedata, 0, bytedata.Length);
            }
            catch
            {
                returnData = strPath;
            }
            return returnData;
        }

        /// <summary>
        /// Base64解码,采用utf8编码方式解码
        /// </summary>
        /// <param name="strPath">待解码的密文</param>
        /// <returns>Base64解码的明文字符串</returns>
        public static string Base64DesEncrypt(string strPath)
        {
            string returnData;
            byte[] bpath = Convert.FromBase64String(strPath);
            try
            {
                returnData = Encoding.UTF8.GetString(bpath);
            }
            catch
            {
                returnData = strPath;
            }
            return returnData;
        }
        #endregion

三、SHA加密解密

  • SHA1加密算法与MD5加密类似,都是不可逆的,只是算法不同。
        /// <summary>
        /// SHA1 加密 
        /// </summary>
        /// <param name="content">需要加密字符串</param>
        /// <param name="encode">指定加密编码</param>
        /// <param name="upperOrLower">大小写格式(大写:X2;小写:x2)默认小写</param> 
        public static string SHA1Encrypt(string content, Encoding encode, string upperOrLower = "x2")
        {
            try
            {
                var buffer = encode.GetBytes(content);//用指定编码转为bytes数组
                var data = SHA1.Create().ComputeHash(buffer);
                var sb = new StringBuilder();
                foreach (var t in data)
                {
                    sb.Append(t.ToString(upperOrLower));
                }

                return sb.ToString();
            }
            catch (Exception ex)
            {
                return "SHA1加密出错:" + ex.Message;
            }
        }

        /// <summary>
        /// SHA256加密
        /// </summary>
        /// <param name="strIN">要加密的string字符串</param>
        /// <returns>SHA256加密之后的密文</returns>
        public static string SHA256Encrypt(string strIN)
        {
            byte[] tmpByte;
            SHA256 sha256 = new SHA256Managed();
            tmpByte = sha256.ComputeHash(GetKeyByteArray(strIN));

            StringBuilder rst = new StringBuilder();
            for (int i = 0; i < tmpByte.Length; i++)
            {
                rst.Append(tmpByte[i].ToString("x2"));
            }
            sha256.Clear();
            return rst.ToString();
        }
        
        /// <summary>
        /// 获取要加密的string字符串字节数组
        /// </summary>
        /// <param name="strKey">待加密字符串</param>
        /// <returns>加密数组</returns>
        private static byte[] GetKeyByteArray(string strKey)
        {
            UTF8Encoding Asc = new UTF8Encoding();
            int tmpStrLen = strKey.Length;
            byte[] tmpByte = new byte[tmpStrLen - 1];
            tmpByte = Asc.GetBytes(strKey);
            return tmpByte;
        }

四、HmacSHA256 Base64加密

        /// <summary>
        /// HmacSHA256 Base64算法,返回的结果始终是32位
        /// </summary>
        /// <param name="message">待加密的明文字符串</param>
        /// <returns>HmacSHA256算法加密之后的密文</returns>
        public static string HmacSHA256(string message)
        {
            byte[] keyByte = Encoding.GetEncoding("utf-8").GetBytes(_appSecret);
            byte[] messageBytes = Encoding.GetEncoding("utf-8").GetBytes(message);
            using (var hmacsha256 = new HMACSHA256(keyByte))
            {
                byte[] hashmessage = hmacsha256.ComputeHash(messageBytes);
                return Convert.ToBase64String(hashmessage);
            }
        }

五、DES加密解密

  • DES(Data Encryption Standard)是目前最为流行的加密算法之一。DES是对称的,也就是说它使用同一个**来加密和解密数据。
  • DES还是一种分组加密算法,该算法每次处理固定长度的数据段,称之为分组。
  • DES加密算法对**有要求,必须是8个字符,如12345678这样的。
        #region  DES加密解密
        /// <summary>
        /// DES加密操作
        /// </summary>
        /// <param name="normalTxt">需要加密的明文字符串</param>
        /// <returns>返回DES加密的密文字符串</returns>
        public static string DesEncrypt(string normalTxt)
        {
            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            int i = cryptoProvider.KeySize;
            MemoryStream ms = new MemoryStream();
            CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(_KEY, _IV), CryptoStreamMode.Write);
            StreamWriter sw = new StreamWriter(cst);
            sw.Write(normalTxt);
            sw.Flush();
            cst.FlushFinalBlock();
            sw.Flush();

            string strRet = Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);
            return strRet;
        }

        /// <summary>
        /// DES解密操作
        /// </summary>
        /// <param name="securityTxt">需要解密的密文字符串</param>
        /// <returns>返回DES解密之后的明文字符串</returns>
        public static string DesDecrypt(string securityTxt)//解密  
        {
            byte[] byEnc;
            try
            {
                securityTxt.Replace("_%_", "/");
                securityTxt.Replace("-%-", "#");
                byEnc = Convert.FromBase64String(securityTxt);
            }
            catch
            {
                return null;
            }
            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            MemoryStream ms = new MemoryStream(byEnc);
            CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(_KEY, _IV), CryptoStreamMode.Read);
            StreamReader sr = new StreamReader(cst);
            return sr.ReadToEnd();
        }
#endregion

六、AES加密解密

  • 高级加密标准(AES,Advanced Encryption Standard)为最常见的对称加密算法(微信小程序加密传输就是用这个加密算法的)
#region AES加密解密
        /// <summary>
        ///  AES base64 加密算法;Key 为16位
        /// </summary>
        /// <param name="Data">需要加密的字符串</param>
        /// <returns></returns>
        public static string RST_AesEncrypt_Base64(string Data)
        {
            if (string.IsNullOrEmpty(Data))
            {
                return null;
            }
            if (string.IsNullOrEmpty(Key))
            {
                return null;
            }
            string Vector = Key.Substring(0, 16);
            Byte[] plainBytes = Encoding.UTF8.GetBytes(Data);
            Byte[] bKey = new Byte[32];
            Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);
            Byte[] bVector = new Byte[16];
            Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);
            Byte[] Cryptograph = null; // 加密后的密文  
            Rijndael Aes = Rijndael.Create();
            //add 
            Aes.Mode = CipherMode.CBC;//兼任其他语言的des
            Aes.BlockSize = 128;
            Aes.Padding = PaddingMode.PKCS7;
            //add end
            try
            {
                // 开辟一块内存流  
                using (MemoryStream Memory = new MemoryStream())
                {
                    // 把内存流对象包装成加密流对象  
                    using (CryptoStream Encryptor = new CryptoStream(Memory,
                     Aes.CreateEncryptor(bKey, bVector),
                     CryptoStreamMode.Write))
                    {
                        // 明文数据写入加密流  
                        Encryptor.Write(plainBytes, 0, plainBytes.Length);
                        Encryptor.FlushFinalBlock();

                        Cryptograph = Memory.ToArray();
                    }
                }
            }
            catch
            {
                Cryptograph = null;
            }
            return Convert.ToBase64String(Cryptograph);
        }

        /// <summary>
        ///  AES base64 解密算法;Key为16位
        /// </summary>
        /// <param name="Data">需要解密的字符串</param>
        /// <param name="Key">Key为16位 **</param>
        /// <returns></returns>
        public static string RST_AesDecrypt_Base64(string Data)
        {
            try
            {
                if (string.IsNullOrEmpty(Data))
                {
                    return null;
                }
                if (string.IsNullOrEmpty(Key))
                {
                    return null;
                }
                string Vector = Key.Substring(0, 16);
                Byte[] encryptedBytes = Convert.FromBase64String(Data);
                Byte[] bKey = new Byte[32];
                Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);
                Byte[] bVector = new Byte[16];
                Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);
                Byte[] original = null; // 解密后的明文  
                Rijndael Aes = Rijndael.Create();
                //add 
                Aes.Mode = CipherMode.CBC;//兼任其他语言的des
                Aes.BlockSize = 128;
                Aes.Padding = PaddingMode.PKCS7;
                //add end
                try
                {
                    // 开辟一块内存流,存储密文  
                    using (MemoryStream Memory = new MemoryStream(encryptedBytes))
                    {
                        //把内存流对象包装成加密流对象  
                        using (CryptoStream Decryptor = new CryptoStream(Memory,
                        Aes.CreateDecryptor(bKey, bVector),
                        CryptoStreamMode.Read))
                        {
                            // 明文存储区  
                            using (MemoryStream originalMemory = new MemoryStream())
                            {
                                Byte[] Buffer = new Byte[1024];
                                Int32 readBytes = 0;
                                while ((readBytes = Decryptor.Read(Buffer, 0, Buffer.Length)) > 0)
                                {
                                    originalMemory.Write(Buffer, 0, readBytes);
                                }
                                original = originalMemory.ToArray();
                            }
                        }
                    }
                }
                catch
                {
                    original = null;
                }
                return Encoding.UTF8.GetString(original);
            }
            catch { return null; }
        }

        /// <summary>
        /// **16位或者32位的AES base64加密
        /// </summary>
        /// <param name="value">需要进行加密的明文字符串</param>
        /// <param name="key">16位或者32位的**</param>
        /// <param name="iv">16位以上的向量;默认为:"*[email protected]_Ztl_99*"</param>
        /// <returns>AES加密之后的密文</returns>
        public static string AesEncrypt(string value, string key, string iv = "")
        {
            if (string.IsNullOrEmpty(value)) return string.Empty;
            if (string.IsNullOrEmpty(key))
            {
                key = Key;
            }
            if (key.Length < 16) throw new Exception("指定的**长度不能少于16位。");
            if (key.Length > 32) throw new Exception("指定的**长度不能多于32位。");
            if (key.Length != 16 && key.Length != 24 && key.Length != 32) throw new Exception("指定的**长度不明确。");
            if (string.IsNullOrEmpty(iv))
            {
                iv = vector;
            }
            if (!string.IsNullOrEmpty(iv))
            {
                if (iv.Length < 16) throw new Exception("指定的向量长度不能少于16位。");
            }

            var _keyByte = Encoding.UTF8.GetBytes(key);
            var _valueByte = Encoding.UTF8.GetBytes(value);
            using (var aes = new RijndaelManaged())
            {
                aes.IV = !string.IsNullOrEmpty(iv) ? Encoding.UTF8.GetBytes(iv) : Encoding.UTF8.GetBytes(key.Substring(0, 16));
                aes.Key = _keyByte;
                aes.Mode = CipherMode.CBC;
                aes.Padding = PaddingMode.PKCS7;
                var cryptoTransform = aes.CreateEncryptor();
                var resultArray = cryptoTransform.TransformFinalBlock(_valueByte, 0, _valueByte.Length);
                return Convert.ToBase64String(resultArray, 0, resultArray.Length);
            }
        }

        /// <summary>
        /// **16位或者32位的AES base64解密
        /// </summary>
        /// <param name="value">需要解密的密文</param>
        /// <param name="key">16位或者32位的**需和加密时的**保持一致</param>
        /// <param name="iv">16位以上的向量需和加密时的向量保持一致;默认为:"*[email protected]_Ztl_99*"</param>
        /// <returns>AES解密之后的明文</returns>
        public static string AesDecrypt(string value, string key, string iv = "")
        {
            if (string.IsNullOrEmpty(value)) return string.Empty;
            if (string.IsNullOrEmpty(key))
            {
                key = Key;
            }
            if (key.Length < 16) throw new Exception("指定的**长度不能少于16位。");
            if (key.Length > 32) throw new Exception("指定的**长度不能多于32位。");
            if (key.Length != 16 && key.Length != 24 && key.Length != 32) throw new Exception("指定的**长度不明确。");
            if (string.IsNullOrEmpty(iv))
            {
                iv = vector;
            }
            if (!string.IsNullOrEmpty(iv))
            {
                if (iv.Length < 16) throw new Exception("指定的向量长度不能少于16位。");
            }

            var _keyByte = Encoding.UTF8.GetBytes(key);
            var _valueByte = Convert.FromBase64String(value);
            using (var aes = new RijndaelManaged())
            {
                aes.IV = !string.IsNullOrEmpty(iv) ? Encoding.UTF8.GetBytes(iv) : Encoding.UTF8.GetBytes(key.Substring(0, 16));
                aes.Key = _keyByte;
                aes.Mode = CipherMode.CBC;
                aes.Padding = PaddingMode.PKCS7;
                var cryptoTransform = aes.CreateDecryptor();
                var resultArray = cryptoTransform.TransformFinalBlock(_valueByte, 0, _valueByte.Length);
                return Encoding.UTF8.GetString(resultArray);
            }
        }
        #endregion

七、RSA加密解密:采用公钥,私钥的模式

  • RSA加密采用公钥加密,私钥解密的模式或者私钥加密,公钥解密的模式。Https的数字证书也是使用这种模式加密的。
  • 但是RSA加密有个特点,就是他对被加密的字符串有长度限制;待加密的字节数不能超过**的长度值除以8再减去11(即:RSACryptoServiceProvider.KeySize / 8 - 11,而加密后得到密文的字节数,正好是**的长度值除以 8(即:RSACryptoServiceProvider.KeySize / 8)。注:该长度指的是byte[]数组的长度,而不是字符串的长度,简单来说,就是被加密字符串不能太长。
        #region RSA加密解密:采用公钥,私钥的模式

        #region 私钥加密,公钥解密

        /// <summary>
        /// RSA私钥加密
        /// </summary>
        /// <param name="privateKey">Java格式的RSA私钥 base64格式</param>
        /// <param name="contentData">待加密的数据;调用方法Encoding.GetEncoding("UTF-8").GetBytes(contentData)</param>
        /// <param name="algorithm">加密算法</param>
        /// <returns>RSA私钥加密之后的密文</returns>
        public static string EncryptWithPrivateKey(string privateKey, byte[] contentData, string algorithm = "RSA/ECB/PKCS1Padding")
        {
            return Convert.ToBase64String(EncryptWithPrivateKey(Convert.FromBase64String(privateKey), contentData, algorithm));
        }

        private static byte[] Transform(AsymmetricKeyParameter key, byte[] contentData, string algorithm, bool forEncryption)
        {
            var c = CipherUtilities.GetCipher(algorithm);
            c.Init(forEncryption, new ParametersWithRandom(key));
            return c.DoFinal(contentData);
        }

        /// <summary>
        /// RSA私钥加密
        /// </summary>
        /// <param name="privateKey">Java格式的RSA私钥</param>
        /// <param name="contentData">待加密的数据;调用方法Encoding.GetEncoding("UTF-8").GetBytes(contentData)</param>
        /// <param name="algorithm">加密算法</param>
        /// <returns>RSA私钥加密之后的密文</returns>
        public static byte[] EncryptWithPrivateKey(byte[] privateKey, byte[] contentData, string algorithm = "RSA/ECB/PKCS1Padding")
        {
            RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(privateKey);
            return Transform(privateKeyParam, contentData, algorithm, true);
        }

        /// <summary>
        /// RSA公钥解密
        /// </summary>
        /// <param name="publicKey">Java格式的RSA公钥  base64格式</param>
        /// <param name="content">待解密数据 base64格式</param>
        /// <param name="encoding">解密出来的数据编码格式,默认UTF-8</param>
        /// <param name="algorithm">加密算法</param>
        /// <returns>RSA私钥解密之后的明文</returns>
        public static string DecryptWithPublicKey(string publicKey, string content, string encoding = "UTF-8", string algorithm = "RSA/ECB/PKCS1Padding")
        {
            return Encoding.GetEncoding(encoding).GetString(DecryptWithPublicKey(Convert.FromBase64String(publicKey), Convert.FromBase64String(content), algorithm));
        }

        /// <summary>
        /// RSA公钥解密
        /// </summary>
        /// <param name="publicKey">Java格式的RSA公钥</param>
        /// <param name="contentData">待解密数据</param>
        /// <param name="algorithm">加密算法</param>
        /// <returns>RSA私钥解密之后的明文</returns>
        public static byte[] DecryptWithPublicKey(byte[] publicKey, byte[] contentData, string algorithm = "RSA/ECB/PKCS1Padding")
        {
            RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(publicKey);
            return Transform(publicKeyParam, contentData, algorithm, false);
        }
        #endregion

        #region 公钥加密,私钥解密

        /// <summary>
        /// RSA公钥加密
        /// </summary>
        /// <param name="xmlPublicKey">加密公钥;为空则默认系统公钥</param>
        /// <param name="enptStr">需要加密的明文字符串</param>
        /// <param name="encoding">编码格式;默认:UTF-8</param>
        /// <returns>RSA公钥加密的密文</returns>
        public static string RSAEncrypt_Public(string xmlPublicKey, string enptStr, string encoding = "UTF-8")
        {
            if (string.IsNullOrEmpty(xmlPublicKey))
            {
                xmlPublicKey = _publicKey;
            }
            using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())
            {
                byte[] cipherbytes;
                rsa.FromXmlString(xmlPublicKey);
                cipherbytes = rsa.Encrypt(Encoding.GetEncoding(encoding).GetBytes(enptStr), false);
                return Convert.ToBase64String(cipherbytes);
            }
        }

        /// <summary>
        /// RSA私钥解密
        /// </summary>
        /// <param name="xmlPrivateKey">解密私钥;为空则默认系统公钥</param>
        /// <param name="enptStr">需要加密的明文字符串</param>
        /// <param name="encoding">编码格式;默认:UTF-8</param>
        /// <returns>RSA私钥解密的明文</returns>
        public static string RSADecrypt_Private(string xmlPrivateKey, string enptStr, string encoding = "UTF-8")
        {
            if (string.IsNullOrEmpty(xmlPrivateKey))
            {
                xmlPrivateKey = _privateKey;
            }
            using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())
            {
                byte[] cipherbytes;
                rsa.FromXmlString(xmlPrivateKey);
                cipherbytes = rsa.Decrypt(Convert.FromBase64String(enptStr), false);
                return Encoding.GetEncoding(encoding).GetString(cipherbytes);
            }
        }
        #endregion

        #region 使用同一容器的名称进行RSA加密解密

        /// <summary>
        /// 进行 RSA 加密
        /// </summary>
        /// <param name="sourceStr">源字符串</param>
        /// <returns>加密后字符串</returns>
        public static string RsaEncrypt(string sourceStr)
        {
            Param = new CspParameters();
            //密匙容器的名称,保持加密解密一致才能解密成功
            Param.KeyContainerName = "Navis";
            using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(Param))
            {
                //将要加密的字符串转换成字节数组
                byte[] plaindata = Encoding.Default.GetBytes(sourceStr);
                //通过字节数组进行加密
                byte[] encryptdata = rsa.Encrypt(plaindata, false);
                //将加密后的字节数组转换成字符串
                return Convert.ToBase64String(encryptdata);
            }
        }

        /// <summary>
        /// 通过RSA 加密方式进行解密
        /// </summary>
        /// <param name="codingStr">加密字符串</param>
        /// <returns>解密后字符串</returns>
        public static string RsaDesEncrypt(string codingStr)
        {
            Param = new CspParameters();
            Param.KeyContainerName = "Navis";
            using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(Param))
            {
                byte[] encryptdata = Convert.FromBase64String(codingStr);
                byte[] decryptdata = rsa.Decrypt(encryptdata, false);
                return Encoding.Default.GetString(decryptdata);
            }
        }
        #endregion

        #region RSA分段加密:待加密的字符串拆开,每段长度都小于等于限制长度,然后分段加密

        /// <summary>
        /// RSA分段加密
        /// </summary>
        /// <param name="xmlPublicKey">RSA C#公钥</param>
        /// <param name="enptStr">需要进行RSA加密的长字符串</param>
        /// <returns>返回RSA加密后的密文</returns>
        public static String SubRSAEncrypt(string xmlPublicKey, string enptStr)
        {
            RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
            provider.FromXmlString(xmlPublicKey);
            Byte[] bytes = Encoding.Default.GetBytes(enptStr);
            int MaxBlockSize = provider.KeySize / 8 - 11;  //加密块最大长度限制

            if (bytes.Length <= MaxBlockSize)
                return Convert.ToBase64String(provider.Encrypt(bytes, false));

            using (MemoryStream PlaiStream = new MemoryStream(bytes))
            using (MemoryStream CrypStream = new MemoryStream())
            {
                Byte[] Buffer = new Byte[MaxBlockSize];
                int BlockSize = PlaiStream.Read(Buffer, 0, MaxBlockSize);

                while (BlockSize > 0)
                {
                    Byte[] ToEncrypt = new Byte[BlockSize];
                    Array.Copy(Buffer, 0, ToEncrypt, 0, BlockSize);

                    Byte[] Cryptograph = provider.Encrypt(ToEncrypt, false);
                    CrypStream.Write(Cryptograph, 0, Cryptograph.Length);

                    BlockSize = PlaiStream.Read(Buffer, 0, MaxBlockSize);
                }

                return Convert.ToBase64String(CrypStream.ToArray(), Base64FormattingOptions.None);
            }

        }

        /// <summary>
        /// RSA分段解密,应对长字符串
        /// </summary>
        /// <param name="xmlPrivateKey">RSA C#私钥</param>
        /// <param name="enptStr">需要解密的长字符串</param>
        /// <returns>返回RSA分段解密的明文</returns>
        public static String SubRSADecrypt(string xmlPrivateKey, string enptStr)
        {
            RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
            provider.FromXmlString(xmlPrivateKey);
            Byte[] bytes = Convert.FromBase64String(enptStr);
            int MaxBlockSize = provider.KeySize / 8;  //解密块最大长度限制

            if (bytes.Length <= MaxBlockSize)
                return Encoding.Default.GetString(provider.Decrypt(bytes, false));

            using (MemoryStream CrypStream = new MemoryStream(bytes))
            using (MemoryStream PlaiStream = new MemoryStream())
            {
                Byte[] Buffer = new Byte[MaxBlockSize];
                int BlockSize = CrypStream.Read(Buffer, 0, MaxBlockSize);

                while (BlockSize > 0)
                {
                    Byte[] ToDecrypt = new Byte[BlockSize];
                    Array.Copy(Buffer, 0, ToDecrypt, 0, BlockSize);

                    Byte[] Plaintext = provider.Decrypt(ToDecrypt, false);
                    PlaiStream.Write(Plaintext, 0, Plaintext.Length);

                    BlockSize = CrypStream.Read(Buffer, 0, MaxBlockSize);
                }

                return Encoding.Default.GetString(PlaiStream.ToArray());
            }
        }
        #endregion

        #endregion

本文来自博客园,作者:TomLucas

 

相关标签: C#教程