兼容JAVA的RSA加密解密类

最近在进行支付系统的开发，其中遇到了一些平台是RSA算法进行加密解密和签名进行通讯、因为2个平台之间的区别采了不少坑，特地记录一下。

一、 算法依赖于 Org.BouncyCastle包，首先选择自己的项目，右键点击管理“NuGet程序包”.

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二、搜索“BouncyCastle”，下载最多的就是啦。

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三、下面是加密解密类，直接引入系统即可

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Encodings;
using Org.BouncyCastle.Crypto;

namespace My.Common
{
    /// 

    /// 加密工具类
    /// 
    public static class EncryUtils
    {
             
        /// 

        /// RSAJava私钥转换
        /// 
        /// 
        /// 
        public static string RSAPrivateKeyJava2DotNet(string privateKey)
        {
            if (!string.IsNullOrEmpty(privateKey))
            {
                privateKey = privateKey.Trim().Replace(" ", "");
            }

            RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateKey));
            return string.Format(
                "{0}{1}
{2}
{3}{4}{5}{6}{7}",
                Convert.ToBase64String(privateKeyParam.Modulus.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.PublicExponent.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.P.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.Q.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.DP.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.DQ.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.QInv.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.Exponent.ToByteArrayUnsigned())
            );
        }

        /// 

        ///  RSAJava公钥转换
        /// 
        /// 
        /// 
        public static string RSAPublicKeyJava2DotNet(string publicKey)
        {
            if (!string.IsNullOrEmpty(publicKey))
            {
                publicKey = publicKey.Trim().Replace(" ", "");
            }

            RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKey));
            return string.Format(
                "{0}{1}",
                Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()),
                Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned())
            );
        }

        /// 

        /// 用公钥对数据加密（使用私钥也可以）
        /// 
        /// 需要加密的字符串
        /// 公钥加密
        /// 
        public static string RSAEncryptByPublicKey(string message, string pubilcKey)
        {
            //保存明文文件的字节数组
            Byte[] PlaintextData = Encoding.UTF8.GetBytes(message);
            RSACryptoServiceProvider RSACryptography = new RSACryptoServiceProvider();
            RSACryptography.FromXmlString(pubilcKey);

            int MaxBlockSize = RSACryptography.KeySize / 8 - 11;    //加密块最大长度限制
            if (PlaintextData.Length <= MaxBlockSize)
                return Convert.ToBase64String(RSACryptography.Encrypt(PlaintextData, false));

            using (MemoryStream PlaiStream = new MemoryStream(PlaintextData))
            using (MemoryStream CrypStream = new MemoryStream())
            {
                Byte[] Buffer = new Byte[MaxBlockSize];
                int BlockSize = PlaiStream.Read(Buffer, 0, MaxBlockSize);

                while (BlockSize > 0)
                {
                    Byte[] ToEncrypt = new Byte[BlockSize];
                    Array.Copy(Buffer, 0, ToEncrypt, 0, BlockSize);

                    Byte[] Cryptograph = RSACryptography.Encrypt(ToEncrypt, false);
                    CrypStream.Write(Cryptograph, 0, Cryptograph.Length);

                    BlockSize = PlaiStream.Read(Buffer, 0, MaxBlockSize);
                }

                return Convert.ToBase64String(CrypStream.ToArray(), Base64FormattingOptions.None);
            }
        }

        /// 

        /// 使用公钥对数据解密（使用私钥也可以）
        /// 
        /// 
        /// 
        /// 
        /// 
        public static string DecryptPublicKeyJava(string publicKeyJava, string data, string encoding = "UTF-8")
        {
            if (string.IsNullOrEmpty(publicKeyJava))
            {
                return string.Empty;
            }
            if (string.IsNullOrEmpty(data))
            {
                return string.Empty;
            }

            RsaKeyParameters rsaKeyParameters = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKeyJava));          
            byte[] dataToDecrypt = Convert.FromBase64String(data);
            IAsymmetricBlockCipher rsaEngine = new RsaEngine();
            rsaEngine = new Pkcs1Encoding(rsaEngine);  // 这里是指定PCK1算法，如果是其他的算法请自行替换
            rsaEngine.Init(false, rsaKeyParameters);
         
            string result = "";
            for (int j = 0; j < dataToDecrypt.Length / 128; j++)
            {
                byte[] buf = new byte[128];
                for (int i = 0; i < 128; i++)
                {

                    buf[i] = dataToDecrypt[i + 128 * j];
                }
                buf = rsaEngine.ProcessBlock(buf, 0, buf.Length);
                char[] asciiChars = new char[Encoding.GetEncoding(encoding).GetCharCount(buf, 0, buf.Length)];
                Encoding.GetEncoding(encoding).GetChars(buf, 0, buf.Length, asciiChars, 0);
                result += new string(asciiChars);                            
            }
            return result;         
        }      

        /// 

        /// RSA私钥签名算法
        /// 
        /// 
        /// 
        /// 
        public static string RSASignByPrivateKey(string content, string privateKey)
        {
            RSACryptoServiceProvider rsaCsp = new RSACryptoServiceProvider();
            rsaCsp.FromXmlString(privateKey);
            byte[] dataBytes = Encoding.UTF8.GetBytes(content);
            byte[] signatureBytes = rsaCsp.SignData(dataBytes, "SHA1");
            return Convert.ToBase64String(signatureBytes);
        }

        /// 

        /// RSA公钥签名算法
        /// 
        /// 
        /// 
        /// 
        /// 
        public static bool RsaVerifyByPublicKey(string content, string publicKey,string sign)
        {                       
            RSACryptoServiceProvider rsaCsp = new RSACryptoServiceProvider();
            rsaCsp.FromXmlString(publicKey);

            //将base64签名数据转码为字节   
            byte[] orgin = Encoding.UTF8.GetBytes(content);
            byte[] signedBase64 = Convert.FromBase64String(sign);
            bool bVerify = rsaCsp.VerifyData(orgin, "SHA1", signedBase64);
            return bVerify;
        }
    }
}

使用方法

1、使用EncryUtils.RSAPrivateKeyJava2DotNet 或者 EncryUtils.RSAPublicKeyJava2DotNet 方法。将JAVA的RSA密钥换转换为NET的密钥格式。

2、使用转换后的密钥进行加密，解密，签名等操作。