(C # Foundation) various cryptographic learning

Before, always want to do an understanding of this, but always insist on not go on, very impatient. Recently read a few times articles, very touched, so again to start learning, from the most basic start-the so-called "slow is fast." The mentality has changed, go on! On the code!

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;usingSystem.Security.Cryptography;namespacedazilianxi.wenjian{ Public classRsacryptohelper {//Encrypt         Public Static stringEncrypt (stringPublickeyxml,stringplaintext) {RSACryptoServiceProvider provider=NewRSACryptoServiceProvider (); Provider. Fromxmlstring (Publickeyxml); //initializing an object with a public key            byte[] Plaindata =Encoding.Default.GetBytes (plaintext); byte[] EncryptedData = provider. Encrypt (Plaindata,true); returnconvert.tobase64string (EncryptedData); }        //decryption         Public Static stringDecrypt (stringPrivatekeyxml,stringencryptedtext) {RSACryptoServiceProvider provider=NewRSACryptoServiceProvider (); Provider.            Fromxmlstring (Privatekeyxml); byte[] EncryptedData =convert.frombase64string (Encryptedtext); byte[] Plaindata = provider. Decrypt (EncryptedData,true); stringplaintext =Encoding.Default.GetString (Plaindata); returnplaintext; }         Public Statickeyvaluepair<string,string>Creatersakey () {RSACryptoServiceProvider RSA=NewRSACryptoServiceProvider (); stringPrivatekey = RSA. Toxmlstring (true); stringPublicKey = RSA. Toxmlstring (false); return Newkeyvaluepair<string,string>(PublicKey, Privatekey); }         Public Static stringSignData (stringPlainText,stringprivatekeyxml) {RSACryptoServiceProvider provider=NewRSACryptoServiceProvider (); Provider.            Fromxmlstring (Privatekeyxml); byte[] Plaindata =Encoding.Default.GetBytes (plaintext); //set the algorithm to get the digestHashAlgorithm SHA1 = Hashalgorithm.create ("SHA1"); //get a signed digest, which is a digest encrypted with a private key            byte[] Signeddigest =provider.            SignData (Plaindata, SHA1); returnconvert.tobase64string (signeddigest); }         Public Static BOOLVerifydata (stringPlainText,stringSignaturestringpublickeyxml) {RSACryptoServiceProvider provider=NewRSACryptoServiceProvider (); Provider.            Fromxmlstring (Publickeyxml); byte[] Plaindata =Encoding.Default.GetBytes (plaintext); byte[] Signeddigest =convert.frombase64string (signature); HashAlgorithm SHA1= Hashalgorithm.create ("SHA1"); BOOLIsdataintact =provider.            Verifydata (Plaindata, SHA1, signeddigest); returnisdataintact; }        //using Singnhash         Public Static stringSIGNDATA2 (stringPlainText,stringprivatekeyxml) {RSACryptoServiceProvider provider=NewRSACryptoServiceProvider (); Provider.            Fromxmlstring (Privatekeyxml); byte[] Plaindata =Encoding.Default.GetBytes (plaintext); //set the algorithm to get the digestHashAlgorithm SHA1 = Hashalgorithm.create ("SHA1"); //get the original summary            byte[] Digestdata =Sha1.computehash (Plaindata); //to sign an element digest            byte[] Signeddigest = provider. Signhash (Digestdata,"SHA1"); returnconvert.tobase64string (signeddigest); }        //using Verifyhash         Public Static BOOLVERIFYDATA2 (stringPlainText,stringSigneddigest,stringpublickeyxml) {RSACryptoServiceProvider provider=NewRSACryptoServiceProvider (); Provider.            Fromxmlstring (Publickeyxml); byte[] Plaindata =Encoding.Default.GetBytes (plaintext); byte[] Signeddigestdata =convert.frombase64string (signeddigest); //get a local summaryHashAlgorithm SHA1 = Hashalgorithm.create ("SHA1"); byte[] Digest =Sha1.computehash (Plaindata); //decrypting a signature            BOOLIsdataintact = provider. Verifyhash (Digest,"SHA1", Signeddigestdata); returnisdataintact; }    }}

RSACryptoServiceProvider Provider =NewRSACryptoServiceProvider (); stringPublicprivate = provider. Toxmlstring (true);//get a public/private key pair//string publiconly = provider. Toxmlstring (FALSE); //get only the public key//string key = "secret key";            stringstr ="Hello World"; //string str2 = "Hello World"; //Encrypt            stringEncryptedtext =rsacryptohelper.encrypt (publicprivate, str);            Console.WriteLine (Encryptedtext); //learned the refactoring, this is the flexible use of the constructor function.            Cannot directly meet the conditions, it is necessary to find ways to create appropriate. //decryption            stringCleartext =Rsacryptohelper.decrypt (Publicprivate, encryptedtext);            Console.WriteLine (cleartext); stringOriginaldata ="The article is good, this is my signature: Obama! "; Console.WriteLine ("Number of signatures: {0}", Originaldata); KeyValuePair<string,string> KeyPair =Rsacryptohelper.creatersakey (); stringPrivatekey =Keypair.value; stringPublicKey =Keypair.key; //1, generate the signature, through the digest algorithm            stringSigneddata =Rsacryptohelper.signdata (Originaldata, Privatekey); Console.WriteLine ("digital Signature 1:{0}", Signeddata); //2. Verifying Signatures            BOOLVerify =Rsacryptohelper.verifydata (Originaldata, Signeddata, PublicKey); Console.WriteLine ("Signature Verification Result: {0}", verify); stringSIGNEDDATA2 =rsacryptohelper.signdata2 (Originaldata, Privatekey); Console.WriteLine ("digital Signature 2:{0}", SIGNEDDATA2); //2. Verifying Signatures            BOOLVerify2 =rsacryptohelper.verifydata2 (Originaldata, SignedData2, PublicKey); Console.WriteLine ("signature validation result 2:{0}", verify2); 

Reference, extended study:

Data encryption: http://www.cnblogs.com/yank/p/3528548.html

Digital Signature: http://www.cnblogs.com/yank/p/3533998.html

Certificate: http://www.cnblogs.com/Microshaoft/archive/2009/05/19/1460641.html

Encryption: http://www.cnblogs.com/Microshaoft/archive/2008/07/21/1247584.html

Encryption: http://www.cnblogs.com/darrenji/p/3677458.html

(C # Foundation) various cryptographic learning