这个C#类自定义RSA加密解密及RSA签名和验证，包含了RSA加密、解密及签名所需的相关函数，带有详细的注释说明。

using System;  using System.Text;  using System.Security.Cryptography;  namespace DotNet.Utilities  {      /// <summary>      /// RSA加密解密及RSA签名和验证      /// </summary>      public class RSACryption      {                public RSACryption()          {                    }                        #region RSA 加密解密             #region RSA 的密钥产生                 /// <summary>          /// RSA 的密钥产生 产生私钥 和公钥          /// </summary>          /// <param name="xmlKeys"></param>          /// <param name="xmlPublicKey"></param>          public void RSAKey(out string xmlKeys,out string xmlPublicKey)          {                            System.Security.Cryptography.RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();                  xmlKeys=rsa.ToXmlString(true);                  xmlPublicKey = rsa.ToXmlString(false);                   }          #endregion             #region RSA的加密函数          //##############################################################################          //RSA 方式加密          //说明KEY必须是XML的行式,返回的是字符串          //在有一点需要说明！！该加密方式有 长度 限制的！！          //##############################################################################             //RSA的加密函数  string          public string RSAEncrypt(string xmlPublicKey,string m_strEncryptString )          {                             byte[] PlainTextBArray;              byte[] CypherTextBArray;              string Result;              RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();              rsa.FromXmlString(xmlPublicKey);              PlainTextBArray = (new UnicodeEncoding()).GetBytes(m_strEncryptString);              CypherTextBArray = rsa.Encrypt(PlainTextBArray, false);              Result=Convert.ToBase64String(CypherTextBArray);              return Result;                         }          //RSA的加密函数 byte[]          public string RSAEncrypt(string xmlPublicKey,byte[] EncryptString )          {                             byte[] CypherTextBArray;              string Result;              RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();              rsa.FromXmlString(xmlPublicKey);              CypherTextBArray = rsa.Encrypt(EncryptString, false);              Result=Convert.ToBase64String(CypherTextBArray);              return Result;                         }          #endregion             #region RSA的解密函数          //RSA的解密函数  string          public string RSADecrypt(string xmlPrivateKey, string m_strDecryptString )          {                        byte[] PlainTextBArray;              byte[] DypherTextBArray;              string Result;              System.Security.Cryptography.RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();              rsa.FromXmlString(xmlPrivateKey);              PlainTextBArray =Convert.FromBase64String(m_strDecryptString);              DypherTextBArray=rsa.Decrypt(PlainTextBArray, false);              Result=(new UnicodeEncoding()).GetString(DypherTextBArray);              return Result;                         }             //RSA的解密函数  byte          public string RSADecrypt(string xmlPrivateKey, byte[] DecryptString )          {                        byte[] DypherTextBArray;              string Result;              System.Security.Cryptography.RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();              rsa.FromXmlString(xmlPrivateKey);              DypherTextBArray=rsa.Decrypt(DecryptString, false);              Result=(new UnicodeEncoding()).GetString(DypherTextBArray);              return Result;                         }          #endregion             #endregion             #region RSA数字签名             #region 获取Hash描述表          //获取Hash描述表 ，sharejs.com          public bool GetHash(string m_strSource, ref byte[] HashData)          {                        //从字符串中取得Hash描述              byte[] Buffer;              System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");              Buffer = System.Text.Encoding.GetEncoding("GB2312").GetBytes(m_strSource);              HashData = MD5.ComputeHash(Buffer);                 return true;                     }             //获取Hash描述表          public bool GetHash(string m_strSource, ref string strHashData)          {                             //从字符串中取得Hash描述              byte[] Buffer;              byte[] HashData;              System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");              Buffer = System.Text.Encoding.GetEncoding("GB2312").GetBytes(m_strSource);              HashData = MD5.ComputeHash(Buffer);                 strHashData = Convert.ToBase64String(HashData);              return true;                         }             //获取Hash描述表          public bool GetHash(System.IO.FileStream objFile, ref byte[] HashData)          {                             //从文件中取得Hash描述              System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");              HashData = MD5.ComputeHash(objFile);              objFile.Close();                 return true;                         }             //获取Hash描述表          public bool GetHash(System.IO.FileStream objFile, ref string strHashData)          {                             //从文件中取得Hash描述              byte[] HashData;              System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");              HashData = MD5.ComputeHash(objFile);              objFile.Close();                 strHashData = Convert.ToBase64String(HashData);                 return true;                         }          #endregion             #region RSA签名          //RSA签名          public bool SignatureFormatter(string p_strKeyPrivate, byte[] HashbyteSignature, ref byte[] EncryptedSignatureData)          {                                 System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();                     RSA.FromXmlString(p_strKeyPrivate);                  System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);                  //设置签名的算法为MD5                  RSAFormatter.SetHashAlgorithm("MD5");                  //执行签名                  EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);                     return true;                         }             //RSA签名          public bool SignatureFormatter(string p_strKeyPrivate, byte[] HashbyteSignature, ref string m_strEncryptedSignatureData)          {                                 byte[] EncryptedSignatureData;                     System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();                     RSA.FromXmlString(p_strKeyPrivate);                  System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);                  //设置签名的算法为MD5                  RSAFormatter.SetHashAlgorithm("MD5");                  //执行签名                  EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);                     m_strEncryptedSignatureData = Convert.ToBase64String(EncryptedSignatureData);                     return true;                         }             //RSA签名          public bool SignatureFormatter(string p_strKeyPrivate, string m_strHashbyteSignature, ref byte[] EncryptedSignatureData)          {                                 byte[] HashbyteSignature;                     HashbyteSignature = Convert.FromBase64String(m_strHashbyteSignature);                  System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();                     RSA.FromXmlString(p_strKeyPrivate);                  System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);                  //设置签名的算法为MD5                  RSAFormatter.SetHashAlgorithm("MD5");                  //执行签名                  EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);                     return true;                         }             //RSA签名          public bool SignatureFormatter(string p_strKeyPrivate, string m_strHashbyteSignature, ref string m_strEncryptedSignatureData)          {                                 byte[] HashbyteSignature;                  byte[] EncryptedSignatureData;                     HashbyteSignature = Convert.FromBase64String(m_strHashbyteSignature);                  System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();                     RSA.FromXmlString(p_strKeyPrivate);                  System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);                  //设置签名的算法为MD5                  RSAFormatter.SetHashAlgorithm("MD5");                  //执行签名                  EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);                     m_strEncryptedSignatureData = Convert.ToBase64String(EncryptedSignatureData);                     return true;                         }          #endregion             #region RSA 签名验证             public bool SignatureDeformatter(string p_strKeyPublic, byte[] HashbyteDeformatter, byte[] DeformatterData)          {                                 System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();                     RSA.FromXmlString(p_strKeyPublic);                  System.Security.Cryptography.RSAPKCS1SignatureDeformatter RSADeformatter = new System.Security.Cryptography.RSAPKCS1SignatureDeformatter(RSA);                  //指定解密的时候HASH算法为MD5                  RSADeformatter.SetHashAlgorithm("MD5");                     if(RSADeformatter.VerifySignature(HashbyteDeformatter,DeformatterData))                  {                      return true;                  }                  else                  {                      return false;                  }                         }             public bool SignatureDeformatter(string p_strKeyPublic, string p_strHashbyteDeformatter, byte[] DeformatterData)          {                                 byte[] HashbyteDeformatter;                     HashbyteDeformatter = Convert.FromBase64String(p_strHashbyteDeformatter);                     System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();                     RSA.FromXmlString(p_strKeyPublic);                  System.Security.Cryptography.RSAPKCS1SignatureDeformatter RSADeformatter = new System.Security.Cryptography.RSAPKCS1SignatureDeformatter(RSA);                  //指定解密的时候HASH算法为MD5                  RSADeformatter.SetHashAlgorithm("MD5");                     if(RSADeformatter.VerifySignature(HashbyteDeformatter,DeformatterData))                  {                      return true;                  }                  else                  {                      return false;                  }                         }             public bool SignatureDeformatter(string p_strKeyPublic, byte[] HashbyteDeformatter, string p_strDeformatterData)          {                                 byte[] DeformatterData;                     System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();                     RSA.FromXmlString(p_strKeyPublic);                  System.Security.Cryptography.RSAPKCS1SignatureDeformatter RSADeformatter = new System.Security.Cryptography.RSAPKCS1SignatureDeformatter(RSA);                  //指定解密的时候HASH算法为MD5                  RSADeformatter.SetHashAlgorithm("MD5");                     DeformatterData =Convert.FromBase64String(p_strDeformatterData);                     if(RSADeformatter.VerifySignature(HashbyteDeformatter,DeformatterData))                  {                      return true;                  }                  else                  {                      return false;                  }                         }             public bool SignatureDeformatter(string p_strKeyPublic, string p_strHashbyteDeformatter, string p_strDeformatterData)          {                                 byte[] DeformatterData;                  byte[] HashbyteDeformatter;                     HashbyteDeformatter = Convert.FromBase64String(p_strHashbyteDeformatter);                  System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();                     RSA.FromXmlString(p_strKeyPublic);                  System.Security.Cryptography.RSAPKCS1SignatureDeformatter RSADeformatter = new System.Security.Cryptography.RSAPKCS1SignatureDeformatter(RSA);                  //指定解密的时候HASH算法为MD5                  RSADeformatter.SetHashAlgorithm("MD5");                     DeformatterData =Convert.FromBase64String(p_strDeformatterData);                     if(RSADeformatter.VerifySignature(HashbyteDeformatter,DeformatterData))                  {                      return true;                  }                  else                  {                      return false;                  }                         }                #endregion                #endregion         }  }