C#做的一个加密/解密的类

转自：http://www.16aspx.com/Article/3904

using System;    
using System.Security.Cryptography;    
using System.Text;    
using System.IO;    
     
namespace SEDO    
{    
    /// <summary>    
    /// SEDO 的摘要说明。    
    /// SEDO 实现的是用一个封装了4种对称加密方法(Des,Rc2,Rijndael,TripleDes)的组件    
    ///    
    /// 注意事项：    
    /// 1:TripleDes和Rijndael加密/解密对象使用16或者24位byte的Key    
    /// 2:Rijndael只能使用16位的初始化向量IV    
    /// 3:Des和Rc2均使用8位Byte的Key和IV    
    /// 4:对需要加密/解密的数据流采用何种方法进行编码/解码，由调用组件的用户自己决定    
    /// 5:密钥和初始化向量IV由使用者自己定义    
    /// 程序员： 罗旭成2010-10-30 lxc880615@163.com    
    /// </summary>    
     
    //定义加密类型的枚举    
    public enum EncryptionAlgorithm { Des = 1, Rc2, Rijndael, TripleDes };    
     
    //定义加密类    
    internal class EncryptTransformer    
    {    
        private EncryptionAlgorithm algorithmID;    
        private byte[] initVec;    
        private byte[] encKey;    
     
        internal EncryptTransformer(EncryptionAlgorithm algId)    
        {    
            //Save the algorithm being used.    
            algorithmID = algId;    
        }    
     
        internal ICryptoTransform GetCryptoServiceProvider(byte[] bytesKey)    
        {    
            //当数据密钥Key或者初始化向量IV为空的时候，    
            //将使用加密对象自动产生的密钥Key或者初始化向量IV    
            switch (algorithmID)    
            {    
                case EncryptionAlgorithm.Des:    
                    {    
                        DES des = new DESCryptoServiceProvider();    
                        des.Mode = CipherMode.CBC;    
     
                        // See if a key was provided    
                        if (null == bytesKey)    
                        {    
                            encKey = des.Key;    
                        }    
                        else   
                        {    
                            des.Key = bytesKey;    
                            encKey = des.Key;    
                        }    
                        // See if the client provided an initialization vector    
                        if (null == initVec)    
                        { // Have the algorithm create one    
                            initVec = des.IV;    
                        }    
                        else   
                        { //No, give it to the algorithm    
                            des.IV = initVec;    
                        }    
                        return des.CreateEncryptor();    
                    }    
                case EncryptionAlgorithm.TripleDes:    
                    {    
                        TripleDES des3 = new TripleDESCryptoServiceProvider();    
                        des3.Mode = CipherMode.CBC;    
                        // See if a key was provided    
                        if (null == bytesKey)    
                        {    
                            encKey = des3.Key;    
                        }    
                        else   
                        {    
                            des3.Key = bytesKey;    
                            encKey = des3.Key;    
                        }    
                        // See if the client provided an IV    
                        if (null == initVec)    
                        { //Yes, have the alg create one    
                            initVec = des3.IV;    
                        }    
                        else   
                        { //No, give it to the alg.    
                            des3.IV = initVec;    
                        }    
                        return des3.CreateEncryptor();    
                    }    
                case EncryptionAlgorithm.Rc2:    
                    {    
                        RC2 rc2 = new RC2CryptoServiceProvider();    
                        rc2.Mode = CipherMode.CBC;    
                        // Test to see if a key was provided    
                        if (null == bytesKey)    
                        {    
                            encKey = rc2.Key;    
                        }    
                        else   
                        {    
                            rc2.Key = bytesKey;    
                            encKey = rc2.Key;    
                        }    
                        // See if the client provided an IV    
                        if (null == initVec)    
                        { //Yes, have the alg create one    
                            initVec = rc2.IV;    
                        }    
                        else   
                        { //No, give it to the alg.    
                            rc2.IV = initVec;    
                        }    
                        return rc2.CreateEncryptor();    
                    }    
                case EncryptionAlgorithm.Rijndael:    
                    {    
                        Rijndael rijndael = new RijndaelManaged();    
                        rijndael.Mode = CipherMode.CBC;    
                        // Test to see if a key was provided    
                        if (null == bytesKey)    
                        {    
                            encKey = rijndael.Key;    
                        }    
                        else   
                        {    
                            rijndael.Key = bytesKey;    
                            encKey = rijndael.Key;    
                        }    
                        // See if the client provided an IV    
                        if (null == initVec)    
                        { //Yes, have the alg create one    
                            initVec = rijndael.IV;    
                        }    
                        else   
                        { //No, give it to the alg.    
                            rijndael.IV = initVec;    
                        }    
                        return rijndael.CreateEncryptor();    
                    }    
                default:    
                    {    
                        throw new CryptographicException("Algorithm ID ''" +    
                        algorithmID +    
                        "'' not supported.");    
                    }    
            }    
        }    
     
        //加密的偏移向量    
        internal byte[] IV    
        {    
            get { return initVec; }    
            set { initVec = value; }    
        }    
        //加密的密钥    
        internal byte[] Key    
        {    
            get { return encKey; }    
            set { encKey = value; }    
        }    
     
    }    
     
    //定义解密类    
    internal class DecryptTransformer    
    {    
        private EncryptionAlgorithm algorithmID;    
        private byte[] initVec;    
        private byte[] encKey;    
     
        internal DecryptTransformer(EncryptionAlgorithm deCryptId)    
        {    
            algorithmID = deCryptId;    
        }    
     
        //加密的偏移向量    
        internal byte[] IV    
        {    
            get { return initVec; }    
            set { initVec = value; }    
        }    
     
        //加密的密钥    
        internal byte[] Key    
        {    
            get { return encKey; }    
            set { encKey = value; }    
        }    
     
        internal ICryptoTransform GetCryptoServiceProvider(byte[] bytesKey)    
        {    
            //当数据密钥Key或者初始化向量IV为空的时候，    
            //将使用加密对象自动产生的密钥Key或者初始化向量IV    
            switch (algorithmID)    
            {    
                case EncryptionAlgorithm.Des:    
                    {    
                        DES des = new DESCryptoServiceProvider();    
                        des.Mode = CipherMode.CBC;    
                        des.Key = bytesKey;    
                        des.IV = initVec;    
                        return des.CreateDecryptor();    
                    }    
                case EncryptionAlgorithm.TripleDes:    
                    {    
                        TripleDES des3 = new TripleDESCryptoServiceProvider();    
                        des3.Mode = CipherMode.CBC;    
                        return des3.CreateDecryptor(bytesKey, initVec);    
                    }    
                case EncryptionAlgorithm.Rc2:    
                    {    
                        RC2 rc2 = new RC2CryptoServiceProvider();    
                        rc2.Mode = CipherMode.CBC;    
                        return rc2.CreateDecryptor(bytesKey, initVec);    
                    }    
                case EncryptionAlgorithm.Rijndael:    
                    {    
                        Rijndael rijndael = new RijndaelManaged();    
                        rijndael.Mode = CipherMode.CBC;    
                        return rijndael.CreateDecryptor(bytesKey, initVec);    
                    }    
                default:    
                    {    
                        throw new CryptographicException("Algorithm ID ''" +    
                        algorithmID +    
                        "'' not supported.");    
                    }    
            }    
        } //end GetCryptoServiceProvider    
     
    }    
     
    //定义加密者类    
    public class Encryptor    
    {    
        private EncryptTransformer transformer;    
        private byte[] initVec;    
        private byte[] encKey;    
     
        public Encryptor(EncryptionAlgorithm algId)    
        {    
            transformer = new EncryptTransformer(algId);    
        }    
     
        public byte[] Encrypt(byte[] bytesData, byte[] bytesKey, byte[] bytesIV)    
        {    
            //设置流对象用来保存加密数据字节流.    
            MemoryStream memStreamEncryptedData = new MemoryStream();    
     
            transformer.IV = bytesIV;    
            transformer.Key = bytesKey;    
     
            ICryptoTransform transform =    
                transformer.GetCryptoServiceProvider(bytesKey);    
            CryptoStream encStream =    
                new CryptoStream(memStreamEncryptedData,    
                    transform, CryptoStreamMode.Write);    
     
            try   
            {    
                //将加密数据写进流对象    
                encStream.Write(bytesData, 0, bytesData.Length);    
            }    
            catch (Exception ex)    
            {    
                throw new Exception("在数据加密的时候出现错误！"+    
                    "错误提示： 
" + ex.Message);    
            }    
     
            //设置加密的Key和初始向量IV属性    
            encKey = transformer.Key;    
            initVec = transformer.IV;    
     
            encStream.FlushFinalBlock();    
            encStream.Close();    
     
            //Send the data back.    
            return memStreamEncryptedData.ToArray();    
        }    
     
        public byte[] IV    
        {    
            get { return initVec; }    
            set { initVec = value; }    
        }    
     
        public byte[] Key    
        {    
            get { return encKey; }    
            set { encKey = value; }    
        }    
     
    }    
     
     
    //定义解密者类    
    public class Decryptor    
    {    
        private DecryptTransformer transformer;    
        private byte[] initVec;    
        private byte[] encKey;    
     
        public Decryptor(EncryptionAlgorithm algId)    
        {    
            transformer = new DecryptTransformer(algId);    
        }    
     
        public byte[] Decrypt(byte[] bytesData,    
            byte[] bytesKey, byte[] bytesIV)    
        {    
            //设置流对象用来保存解密数据字节流.    
            MemoryStream memStreamDecryptedData =    
                new MemoryStream();    
     
            //Pass in the initialization vector.    
            transformer.IV = bytesIV;    
            transformer.Key = bytesKey;    
     
            ICryptoTransform transform =    
                transformer.GetCryptoServiceProvider(bytesKey);    
            CryptoStream decStream =    
                new CryptoStream(memStreamDecryptedData,    
                    transform, CryptoStreamMode.Write);    
     
            try   
            {    
                decStream.Write(bytesData, 0, bytesData.Length);    
            }    
            catch (Exception ex)    
            {    
                throw new Exception("在数据解密的时候出现错误！"+    
                    "错误提示： 
" + ex.Message);    
            }    
            decStream.FlushFinalBlock();    
            decStream.Close();    
            // 返回解密数据.    
            return memStreamDecryptedData.ToArray();    
        }    
     
        public byte[] IV    
        {    
            get { return initVec; }    
            set { initVec = value; }    
        }    
     
        public byte[] Key    
        {    
            get { return encKey; }    
            set { encKey = value; }    
        }    
     
    }    
     
    //类描述：文件加密/解密类    
    public class SecurityFile    
    {    
        private DecryptTransformer Dec_Transformer; //解密转换器    
        private EncryptTransformer Enc_Transformer; //加密转换器    
        private byte[] initVec;    
        private byte[] encKey;    
     
        public SecurityFile(EncryptionAlgorithm algId)    
        {    
            Dec_Transformer = new DecryptTransformer(algId);    
            Enc_Transformer = new EncryptTransformer(algId);    
        }    
     
        //加密的偏移向量    
        internal byte[] IV    
        {    
            get { return initVec; }    
            set { initVec = value; }    
        }    
        //加密的密钥    
        internal byte[] Key    
        {    
            get { return encKey; }    
            set { encKey = value; }    
        }    
     
        //功能描述：加密文件    
        public void EncryptFile(string inFileName,    
            string outFileName, byte[] bytesKey, byte[] bytesIV)    
        {    
            try   
            {    
                FileStream fin =    
                    new FileStream(inFileName, FileMode.Open,    
                        FileAccess.Read);    
                FileStream fout = new FileStream(outFileName,    
                    FileMode.OpenOrCreate, FileAccess.Write);    
                fout.SetLength(0);    
     
                //Create variables to help with read and write.    
                //This is intermediate storage for the encryption.    
                byte[] bin = new byte[100];    
                //This is the total number of bytes written.    
                long rdlen = 0;    
                //This is the total length of the input file.    
                long totlen = fin.Length;    
                //This is the number of bytes to be written at a time.    
                int len;     
     
                Enc_Transformer.IV = bytesIV;    
                Enc_Transformer.Key = bytesKey;    
     
                ICryptoTransform transform =    
                    Enc_Transformer.GetCryptoServiceProvider(bytesKey);    
                CryptoStream encStream =    
                    new CryptoStream(fout, transform, CryptoStreamMode.Write);    
     
                //Read from the input file, then encrypt and write to the output file.    
                while (rdlen < totlen)    
                {    
                    len = fin.Read(bin, 0, 100);    
                    encStream.Write(bin, 0, len);    
                    rdlen = rdlen + len;    
                }    
     
                encStream.Close();    
                fout.Close();    
                fin.Close();    
            }    
            catch (Exception ex)    
            {    
                throw new Exception("在文件加密的时候出现错误！"+    
                    "错误提示： 
" + ex.Message);    
            }    
        }    
     
        //功能描述：解密文件    
        public void DecryptFile(string inFileName,    
            string outFileName, byte[] bytesKey, byte[] bytesIV)    
        {    
            try   
            {    
                FileStream fin =    
                    new FileStream(inFileName, FileMode.Open,    
                        FileAccess.Read);    
                FileStream fout =    
                    new FileStream(outFileName,    
                        FileMode.OpenOrCreate, FileAccess.Write);    
                fout.SetLength(0);    
     
                //Create variables to help with read and write.    
                //This is intermediate storage for the encryption.    
                byte[] bin = new byte[100];    
                //This is the total number of bytes written.    
                long rdlen = 0;    
                //This is the total length of the input file.    
                long totlen = fin.Length;    
                //This is the number of bytes to be written at a time.    
                int len;     
     
                Dec_Transformer.IV = bytesIV;    
                Dec_Transformer.Key = bytesKey;    
     
                ICryptoTransform transform =    
                    Dec_Transformer.GetCryptoServiceProvider(bytesKey);    
                CryptoStream encStream =    
                    new CryptoStream(fout, transform, CryptoStreamMode.Write);    
     
                //Read from the input file, then encrypt and    
                //write to the output file.    
                while (rdlen < totlen)    
                {    
                    len = fin.Read(bin, 0, 100);    
                    encStream.Write(bin, 0, len);    
                    rdlen = rdlen + len;    
                }    
                encStream.Close();    
                fout.Close();    
                fin.Close();    
            }    
            catch (Exception ex)    
            {    
                throw new Exception("在文件加密的时候出现"+    
                    "错误！错误提示： 
" + ex.Message);    
            }    
        }    
    }    
}