//加密解密用到的公钥与私钥
RSACryptoServiceProvider oRSA = new RSACryptoServiceProvider();
string privatekey=oRSA.ToXmlString(true);//私钥
string publickey=oRSA.ToXmlString(false);//公钥
//这两个密钥需要保存下来
byte[] messagebytes = Encoding.UTF8.GetBytes("luo罗"); //需要加密的数据
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//公钥加密
RSACryptoServiceProvider oRSA1 = new RSACryptoServiceProvider();
oRSA1.FromXmlString(publickey); //加密要用到公钥所以导入公钥
byte[] AOutput = oRSA1.Encrypt(messagebytes ,false); //AOutput 加密以后的数据
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//私钥解密
RSACryptoServiceProvider oRSA2 = new RSACryptoServiceProvider();
oRSA2.FromXmlString(privatekey);
byte[] AInput = oRSA2.Decrypt(AOutput, false);
string reslut=Encoding.ASCII.GetString(AInput) 

byte[] messagebytes = Encoding.UTF8.GetBytes("luo罗"); RSACryptoServiceProvider oRSA = new RSACryptoServiceProvider(); string privatekey = oRSA.ToXmlString(true); string publickey = oRSA.ToXmlString(false); //私钥签名 RSACryptoServiceProvider oRSA3 = new RSACryptoServiceProvider(); oRSA3.FromXmlString(privatekey); byte[] AOutput = oRSA3.SignData(messagebytes, "SHA1"); //公钥验证 RSACryptoServiceProvider oRSA4 = new RSACryptoServiceProvider(); oRSA4.FromXmlString(publickey); bool bVerify = oRSA4.VerifyData(messagebytes, "SHA1", AOutput); 

   // 因为一般证书的私钥是不可以导出的所以所以用第2种方法导入私钥的来进行签名行不通
byte[] messagebytes = Encoding.UTF8.GetBytes("luo罗"); string Path = @"D:\Certificate\1.P12"; X509Certificate2 x509 = new X509Certificate2(Path, "12345678"); SHA1 sha1 = new SHA1CryptoServiceProvider(); byte[] hashbytes = sha1.ComputeHash(messagebytes); //对要签名的数据进行哈希 RSAPKCS1SignatureFormatter signe = new RSAPKCS1SignatureFormatter(); signe.SetKey(x509.PrivateKey); //设置签名用到的私钥 signe.SetHashAlgorithm("SHA1"); //设置签名算法 byte[] reslut = signe.CreateSignature(hashbytes);
//验签：与第2方法相同 RSACryptoServiceProvider oRSA4 = new RSACryptoServiceProvider(); oRSA4.FromXmlString(x509.PublicKey.Key.ToXmlString(false)); bool bVerify = oRSA4.VerifyData(messagebytes, "SHA1", reslut); 

 string Path = @"D:\Certificate\1.P12"; X509Certificate2 x509 = new X509Certificate2(Path, "12345678"); byte[] data = System.Text.Encoding.UTF8.GetBytes("cheshi罗");
-//证书公钥加密 RSACryptoServiceProvider oRSA1 = new RSACryptoServiceProvider(); oRSA1.FromXmlString(x509.PublicKey.Key.ToXmlString(false));
-byte[] AOutput = oRSA1.Encrypt(data, false);
-//证书私钥解密 RSACryptoServiceProvider rsa2 = (RSACryptoServiceProvider)x509.PrivateKey; byte[] plainbytes = rsa2.Decrypt(AOutput, false); string reslut = Encoding.UTF8.GetString(plainbytes); 

private void Form1_Load(object sender, EventArgs e) { x509=new X509Certificate2(Path, "12345678"); RSACryptoServiceProvider oRSA1 = new RSACryptoServiceProvider(); Encrypt(); Decrypt();           } private void Decrypt() { string FilePath = "2.txt"; string OutFile = "3.txt"; System.IO.FileStream picfs = new System.IO.FileStream(FilePath, System.IO.FileMode.Open); System.IO.FileStream fs = new System.IO.FileStream(OutFile, System.IO.FileMode.OpenOrCreate); oRSA1 = (RSACryptoServiceProvider)x509.PrivateKey; int blocksize = oRSA1.KeySize/8;
-byte[] buffer, buffer1, encryblock; bool Closed = true; while (Closed) { buffer = null; buffer = new byte[blocksize]; int k = picfs.Read(buffer, 0, buffer.Length); if (k > 0) { if (blocksize == k) { encryblock = oRSA1.Decrypt(buffer, false); fs.Write(encryblock, 0, encryblock.Length); } else { buffer1 = new byte[k]; for (int i = 0; i < k; i++) { buffer1[i] = buffer[i]; } encryblock = oRSA1.Decrypt(buffer1, false); fs.Write(encryblock, 0, encryblock.Length); } } else { picfs.Close(); fs.Close(); Closed = false; } }
-} private void Encrypt() { string FilePath = "1.txt"; string OutFile = "2.txt"; //证书公钥加密
-oRSA1.FromXmlString(x509.PublicKey.Key.ToXmlString(false)); System.IO.FileStream picfs = new System.IO.FileStream(FilePath, System.IO.FileMode.Open); System.IO.FileStream fs = new System.IO.FileStream(OutFile, System.IO.FileMode.OpenOrCreate); int blocksize = 0; if (oRSA1.KeySize == 1024) { blocksize = 16; } else { blocksize = 8; } byte[] buffer, buffer1, encryblock; bool Closed = true; while (Closed) { buffer = null; buffer = new byte[blocksize]; int k = picfs.Read(buffer, 0, buffer.Length); if (k > 0) { if (blocksize == k) { encryblock = oRSA1.Encrypt(buffer, false); fs.Write(encryblock, 0, encryblock.Length); } else { buffer1 = new byte[k]; for (int i = 0; i < k; i++) { buffer1[i] = buffer[i]; } encryblock = oRSA1.Encrypt(buffer1, false); fs.Write(encryblock, 0, encryblock.Length); } } else { picfs.Close(); fs.Close(); Closed = false; } } } 

private void Form1_Load(object sender, EventArgs e){x509 = new X509Certificate2(Path, "12345678");SignFile("1.txt", "11.txt");VerifyFile("1.txt", "11.txt");}private bool VerifyFile(string FileName, string SignedFileName){bool reslut = true;System.IO.StreamReader objread = new System.IO.StreamReader(FileName);System.IO.StreamReader objreadSigned = new System.IO.StreamReader(SignedFileName);RSACryptoServiceProvider VeryRsa = new RSACryptoServiceProvider();VeryRsa.FromXmlString(x509.PublicKey.Key.ToXmlString(false));int Inblocksize = 0;int Signedblocksize = 0;if (VeryRsa.KeySize == 1024){Inblocksize = 16;}else{Inblocksize = 8;}Signedblocksize = VeryRsa.KeySize / 8;bool Closed = true;byte[] Buffer; //原文缓存区byte[] InBuffer;//原文缓存区byte[] Buffer1;//签名文件缓存区while (Closed){Buffer = null;Buffer = new byte[Inblocksize];int k = objread.BaseStream.Read(Buffer, 0, Buffer.Length);if (k > 0){if (Inblocksize == k) //读出来的长度和缓存区一样大
                    {Buffer1 = new byte[Signedblocksize];objreadSigned.BaseStream.Read(Buffer1, 0, Buffer1.Length);reslut = VeryRsa.VerifyData(Buffer,"SHA1",Buffer1);if (!reslut){Closed = false;}}else{ //意思是Buffer没满，只有k个字节，k字节后面全是空所以不需要验签InBuffer = new byte[k];for (int i = 0; i < k; i++){InBuffer[i] = Buffer[i];}Buffer1 = new byte[Signedblocksize];objreadSigned.BaseStream.Read(Buffer1, 0, Buffer1.Length);reslut = VeryRsa.VerifyData(InBuffer, "SHA1", Buffer1);if (!reslut){Closed = false;}}}else{//这里的意思是原文已经读完毕了，并且已经和签名文件对应验签成功，那么//签名文件也必须读完毕了。if (objreadSigned.BaseStream.Position!= objreadSigned.BaseStream.Length){reslut = false;}objreadSigned.Close();objread.Close();Closed = false;}}return reslut;}private void SignFile(string InFileName,string OutFileName){RSACryptoServiceProvider SignRsa = (RSACryptoServiceProvider)x509.PrivateKey;System.IO.StreamReader objread = new System.IO.StreamReader(InFileName);System.IO.StreamWriter objwrite = new System.IO.StreamWriter(OutFileName, false);int blocksize = 0;if (SignRsa.KeySize == 1024){blocksize = 16;}else{blocksize = 8;}bool Closed = true;byte[] Buffer = new byte[blocksize];byte[] buffer1, SignBytes;while (Closed){int k = objread.BaseStream.Read(Buffer, 0, Buffer.Length);if (k > 0){if (k == blocksize){SignBytes = SignRsa.SignData(Buffer, "SHA1");objwrite.BaseStream.Write(SignBytes, 0, SignBytes.Length);}else{buffer1 = new byte[k];for (int i = 0; i < k; i++){buffer1[i] = Buffer[i];}SignBytes = SignRsa.SignData(buffer1, "SHA1");objwrite.BaseStream.Write(SignBytes, 0, SignBytes.Length);}}else{Closed = false;objread.Close();objwrite.Close();}}}

byte[] messagebytes = Encoding.UTF8.GetBytes("LUO罗"); //需要用的对称密钥 DESCryptoServiceProvider Des = new DESCryptoServiceProvider(); byte[] key = Des.Key; //加密 DESCryptoServiceProvider tdesProvider = new DESCryptoServiceProvider(); tdesProvider.Key = key; tdesProvider.Mode = CipherMode.ECB; byte[] encrypted = tdesProvider.CreateEncryptor().TransformFinalBlock(messagebytes, 0, messagebytes.Length); //解密 DESCryptoServiceProvider tdesProvider2 = new DESCryptoServiceProvider(); tdesProvider.Key = key1; tdesProvider.Mode = CipherMode.ECB; byte[] outputdata = tdesProvider.CreateDecryptor().TransformFinalBlock(encrypted, 0, encrypted.Length); string reslut = Encoding.UTF8.GetString(outputdata);
//7用DESCryptoServiceProvider 加解密 流
CryptoStream csDecrypt = new CryptoStream(Stream, Des.CreateEncryptor(), CryptoStreamMode.Write);CryptoStream csDecrypt = new CryptoStream(Stream, Des.CreateDecryptor(), CryptoStreamMode.Write);