C# 与JAVA 的RSA 加密解密交互，互通，C#使用BouncyCastle来实现私钥加密，公钥解密的方法

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

下面直接粘贴代码，不多说：

BouncyCastle相关DLL，估计不用我多说，大家可以百度下载。然后引用就可以了！

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;

namespace CryptionUtils

{

    public class RSAForJava

    {

        public RSAForJava()

        {

        }

        /// <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(),

                new Org.BouncyCastle.Security.SecureRandom(),

                ,   //密钥长度

                );

            //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("\r", "").Replace("\n", "").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("\r", "").Replace("\n", "").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 EncryptByPrivateKey(string s,string key)

        {

            //非对称加密算法，加解密用

            IAsymmetricBlockCipher engine = new Pkcs1Encoding(new RsaEngine());

            //加密  

            try

            {

                engine.Init(true, GetPrivateKeyParameter(key));

                byte[] byteData = System.Text.Encoding.UTF8.GetBytes(s);

                var ResultData = engine.ProcessBlock(byteData, , byteData.Length);

                return Convert.ToBase64String(ResultData);

                //Console.WriteLine("密文（base64编码）:" + Convert.ToBase64String(testData) + Environment.NewLine);

            }

            catch (Exception ex)

            {

                return ex.Message;

            }

        }

        public string DecryptByPublicKey(string s,string key)

        {

            s = s.Replace("\r", "").Replace("\n", "").Replace(" ", "");

            //非对称加密算法，加解密用

            IAsymmetricBlockCipher engine = new Pkcs1Encoding( new RsaEngine());

            //解密  

            try

            {

                engine.Init(false, GetPublicKeyParameter(key));

                byte[] byteData = Convert.FromBase64String(s);

                var ResultData = engine.ProcessBlock(byteData, , byteData.Length);

                return System.Text.Encoding.UTF8.GetString(ResultData);

            }

            catch (Exception ex)

            {

                return ex.Message;

            }

        }

    }

}

C# 与JAVA 的RSA 加密解密交互，互通，C#使用BouncyCastle来实现私钥加密，公钥解密的方法的相关教程结束。