摘要：
因为C#的RSA加密和解密只包括公钥加密和私钥解密。没有私钥加密和公钥解密。邦西城堡的文件很少。很多人可能会说C#也可以通过Biginteger开源类实现。然而，有一篇文章对十六进制结果进行了加密。它根本无法与JAVA通信。甚至加密结果的格式也与C#的原始加密结果不同。接下来，我继续寻找信息和方法。在线验证后发布。您可以进行DEMO，然后进行在线RSA加密和解密验证。
因为C#的RSA加密解密只有公钥加密，私钥解密，没有私钥加密，公钥解密。在网上查了很久也没有很好的实现。BouncyCastle的文档少之又少。很多人可能会说，C#也是可以的，通过Biginteger开源类来实现，不过那个是有一个文章，不过他加密出来的是16进制结果的。根本不能和JAVA互通。连加密出来的都不和C#原生的加密出来的结果格式一样。所以还是没有好的解决方法。
接下来还是不断的找资料，找方法。找朋友找同事。个个都找。问题是有的，方法也是有的，所以总结各路大神之后写了这个类。实现了私钥加密，公钥解密。并通过在线的校验之后，发布上来。大家可以做一个DEMO，然后进去在线RSA加密解密校验。
在线RSA，DES等加密解密地址：
http://tool.chacuo.net/cryptrsapubkey
可以直接nuget搜索BouncyCastle，安装即可
下面是代码：
using System; using System.Collections.Generic; using System.Linq; using System.Text; using Org.BouncyCastle.Asn1.Pkcs; using Org.BouncyCastle.Asn1.X509; using Org.BouncyCastle.Crypto.Generators; using Org.BouncyCastle.Crypto.Parameters; using Org.BouncyCastle.Math; using Org.BouncyCastle.Pkcs; using Org.BouncyCastle.Security; using Org.BouncyCastle.Crypto.Engines; using Org.BouncyCastle.X509; using Org.BouncyCastle.Crypto; using Org.BouncyCastle.Asn1; using Org.BouncyCastle.Crypto.Encodings; using System.IO; namespace Tool { public class RSATool { public RSATool() { } /// <summary> /// KEY 结构体 /// </summary> public struct RSAKEY { /// <summary> /// 公钥 /// </summary> public string PublicKey { get; set; } /// <summary> /// 私钥 /// </summary> public string PrivateKey { get; set; } } public RSAKEY GetKey() { //RSA密钥对的构造器 RsaKeyPairGenerator keyGenerator = new RsaKeyPairGenerator(); //RSA密钥构造器的参数 RsaKeyGenerationParameters param = new RsaKeyGenerationParameters( Org.BouncyCastle.Math.BigInteger.ValueOf(3), new Org.BouncyCastle.Security.SecureRandom(), 1024, //密钥长度 25); //用参数初始化密钥构造器 keyGenerator.Init(param); //产生密钥对 AsymmetricCipherKeyPair keyPair = keyGenerator.GenerateKeyPair(); //获取公钥和密钥 AsymmetricKeyParameter publicKey = keyPair.Public; AsymmetricKeyParameter privateKey = keyPair.Private; SubjectPublicKeyInfo subjectPublicKeyInfo = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(publicKey); PrivateKeyInfo privateKeyInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(privateKey); Asn1Object asn1ObjectPublic = subjectPublicKeyInfo.ToAsn1Object(); byte[] publicInfoByte = asn1ObjectPublic.GetEncoded("UTF-8"); Asn1Object asn1ObjectPrivate = privateKeyInfo.ToAsn1Object(); byte[] privateInfoByte = asn1ObjectPrivate.GetEncoded("UTF-8"); RSAKEY item = new RSAKEY() { PublicKey = Convert.ToBase64String(publicInfoByte), PrivateKey = Convert.ToBase64String(privateInfoByte) }; return item; } private AsymmetricKeyParameter GetPublicKeyParameter(string s) { s = s.Replace(" ", "").Replace(" ", "").Replace(" ", ""); byte[] publicInfoByte = Convert.FromBase64String(s); Asn1Object pubKeyObj = Asn1Object.FromByteArray(publicInfoByte);//这里也可以从流中读取，从本地导入 AsymmetricKeyParameter pubKey = PublicKeyFactory.CreateKey(publicInfoByte); return pubKey; } private AsymmetricKeyParameter GetPrivateKeyParameter(string s) { s = s.Replace(" ", "").Replace(" ", "").Replace(" ", ""); byte[] privateInfoByte = Convert.FromBase64String(s); // Asn1Object priKeyObj = Asn1Object.FromByteArray(privateInfoByte);//这里也可以从流中读取，从本地导入 // PrivateKeyInfo privateKeyInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(privateKey); AsymmetricKeyParameter priKey = PrivateKeyFactory.CreateKey(privateInfoByte); return priKey; } public string EncryptByKey(string s, string key, bool isPublic) { //非对称加密算法，加解密用 IAsymmetricBlockCipher engine = new Pkcs1Encoding(new RsaEngine()); //加密 try { engine.Init(true, isPublic ? GetPublicKeyParameter(key) : GetPrivateKeyParameter(key)); byte[] byteData = System.Text.Encoding.UTF8.GetBytes(s); int inputLen = byteData.Length; MemoryStream ms = new MemoryStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段加密 while (inputLen - offSet > 0) { if (inputLen - offSet > 117) { cache = engine.ProcessBlock(byteData, offSet, 117); } else { cache = engine.ProcessBlock(byteData, offSet, inputLen - offSet); } ms.Write(cache, 0, cache.Length); i++; offSet = i * 117; } byte[] encryptedData = ms.ToArray(); //var ResultData = engine.ProcessBlock(byteData, 0, byteData.Length); return Convert.ToBase64String(encryptedData); //Console.WriteLine("密文（base64编码）:" + Convert.ToBase64String(testData) + Environment.NewLine); } catch (Exception ex) { return ex.Message; } } /// <summary> /// 解密 /// </summary> /// <param name="s"></param> /// <param name="key"></param> /// <param name="isPublic"></param> /// <returns></returns> public string DecryptByPublicKey(string s, string key, bool isPublic) { s = s.Replace(" ", "").Replace(" ", "").Replace(" ", ""); //非对称加密算法，加解密用 IAsymmetricBlockCipher engine = new Pkcs1Encoding(new RsaEngine()); //加密 try { engine.Init(false, isPublic ? GetPublicKeyParameter(key) : GetPrivateKeyParameter(key)); byte[] byteData = Convert.FromBase64String(s); int inputLen = byteData.Length; MemoryStream ms = new MemoryStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段加密 while (inputLen - offSet > 0) { if (inputLen - offSet > 128) { cache = engine.ProcessBlock(byteData, offSet, 128); } else { cache = engine.ProcessBlock(byteData, offSet, inputLen - offSet); } ms.Write(cache, 0, cache.Length); i++; offSet = i * 128; } byte[] encryptedData = ms.ToArray(); //var ResultData = engine.ProcessBlock(byteData, 0, byteData.Length); return Encoding.UTF8.GetString(ms.ToArray()); //Console.WriteLine("密文（base64编码）:" + Convert.ToBase64String(testData) + Environment.NewLine); } catch (Exception ex) { return ex.Message; } } /// <summary> /// 签名 /// </summary> /// <param name="data">数据</param> /// <param name="key">密匙</param> /// <returns></returns> public string SignByPrivateKey(string data, string key) { AsymmetricKeyParameter priKey = GetPrivateKeyParameter(key); byte[] byteData = System.Text.Encoding.UTF8.GetBytes(data); ISigner normalSig = SignerUtilities.GetSigner("SHA1WithRSA"); normalSig.Init(true, priKey); normalSig.BlockUpdate(byteData, 0, data.Length); byte[] normalResult = normalSig.GenerateSignature(); //签名结果 return Convert.ToBase64String(normalResult); //return System.Text.Encoding.UTF8.GetString(normalResult); } /// <summary> /// 验签 /// </summary> /// <param name="plainData">验证数据</param> /// <param name="sign">签名</param> /// <param name="key">公匙</param> /// <returns></returns> public bool ValidationPublicKey(string plainData, string sign, string key) { AsymmetricKeyParameter priKey = GetPublicKeyParameter(key); byte[] signBytes = Convert.FromBase64String(sign); byte[] plainBytes = Encoding.UTF8.GetBytes(plainData); ISigner verifier = SignerUtilities.GetSigner("SHA1WithRSA"); verifier.Init(false, priKey); verifier.BlockUpdate(plainBytes, 0, plainBytes.Length); return verifier.VerifySignature(signBytes); //验签结果 } } }
转自：https://www.cnblogs.com/AnAng/p/10396296.html