Java和.Net互相使用RSA加密时的问题和处理方法

前言

我们产品是使用JAVA语言开发的，有个供第三方获取Token的接口，过程大概就是第三方先调一个注册接口，获取一个RSA公钥，然后用通过公钥加密后的一些认证信息调用获取Token的接口，如果信息无误，则发放Token。

前段时间就遇到了对方是使用.Net进行开发的系统，在第一步获取公钥时没用问题，加密后的信息传过来就怎么都解密不了的情况，后来了解到，C#的默认密钥格式上似乎是略有不同才导致的问题。

NET Framework中，的RSACryptoServiceProvider默认使用Microsoft的专有格式

Java 通常使用PKCS#8格式的私钥和X.509格式的公钥

解决方案

其实C#中转换一下就可以了

示例代码

RsaApi.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Pkcs;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.X509;
using System.Xml;
using System.Text;
using System.Security.Cryptography;

namespace RsaApi
{
    public class RSAConvert
    {
        /// <summary>
        /// RSA私钥格式转换，java->.net
        /// </summary>
        /// <param name="privateKey">java生成的RSA私钥</param>
        /// <returns></returns>
        public static string RSAPrivateKeyJava2DotNet(string privateKey)
        {
            RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateKey));

            return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent><P>{2}</P><Q>{3}</Q><DP>{4}</DP><DQ>{5}</DQ><InverseQ>{6}</InverseQ><D>{7}</D></RSAKeyValue>",
                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()));
        }

        /// <summary>
        /// RSA私钥格式转换，.net->java
        /// </summary>
        /// <param name="privateKey">.net生成的私钥</param>
        /// <returns></returns>
        public static string RSAPrivateKeyDotNet2Java(string privateKey)
        {
            XmlDocument doc = new XmlDocument();
            doc.LoadXml(privateKey);
            BigInteger m = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Modulus")[0].InnerText));
            BigInteger exp = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Exponent")[0].InnerText));
            BigInteger d = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("D")[0].InnerText));
            BigInteger p = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("P")[0].InnerText));
            BigInteger q = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Q")[0].InnerText));
            BigInteger dp = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("DP")[0].InnerText));
            BigInteger dq = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("DQ")[0].InnerText));
            BigInteger qinv = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("InverseQ")[0].InnerText));

            RsaPrivateCrtKeyParameters privateKeyParam = new RsaPrivateCrtKeyParameters(m, exp, d, p, q, dp, dq, qinv);

            PrivateKeyInfo privateKeyInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(privateKeyParam);
            byte[] serializedPrivateBytes = privateKeyInfo.ToAsn1Object().GetEncoded();
            return Convert.ToBase64String(serializedPrivateBytes);
        }

        /// <summary>
        /// RSA公钥格式转换，java->.net
        /// </summary>
        /// <param name="publicKey">java生成的公钥</param>
        /// <returns></returns>
        public static string RSAPublicKeyJava2DotNet(string publicKey)
        {
            RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKey));
            return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>",
                Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()),
                Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned()));
        }

        /// <summary>
        /// RSA公钥格式转换，.net->java
        /// </summary>
        /// <param name="publicKey">.net生成的公钥</param>
        /// <returns></returns>
        public static string RSAPublicKeyDotNet2Java(string publicKey)
        {
            XmlDocument doc = new XmlDocument();
            doc.LoadXml(publicKey);
            BigInteger m = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Modulus")[0].InnerText));
            BigInteger p = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Exponent")[0].InnerText));
            RsaKeyParameters pub = new RsaKeyParameters(false, m, p);

            SubjectPublicKeyInfo publicKeyInfo = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(pub);
            byte[] serializedPublicBytes = publicKeyInfo.ToAsn1Object().GetDerEncoded();
            return Convert.ToBase64String(serializedPublicBytes);
        }

        /// <summary>
        /// rsa加密
        /// </summary>
        /// <param name="xmlPublicKey"></param>
        /// <param name="m_strEncryptString"></param>
        /// <returns></returns>
        public static string RSAEncrypt(string xmlPublicKey, string m_strEncryptString)
        {
            try
            {
                byte[] PlainTextBArray;
                byte[] CypherTextBArray;
                string Result;
                System.Security.Cryptography.RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
                rsa.FromXmlString(xmlPublicKey);
                PlainTextBArray = (new UTF8Encoding()).GetBytes(m_strEncryptString);
                CypherTextBArray = rsa.Encrypt(PlainTextBArray, false);
                Result = Convert.ToBase64String(CypherTextBArray);
                return Result;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

    }
}

Program.cs

using System.Security.Cryptography.X509Certificates;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Security.Cryptography;

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 Program
{
    public class Program
    {
        private static Encoding Encoding_UTF8 = Encoding.UTF8;
        public struct RSAKEY
        {
            public string PublicKey
            {
                get;
                set;
            }
            public string PrivateKey
            {
                get;
                set;
            }
        }

            //// 测试主方法
           static void Main(string[] args)
        {
            Program p =new Program();
            RSAKEY rsa = p.GetKey();

            string publickey = rsa.PublicKey;
            string privateKey = rsa.PrivateKey;
            string s = p.EncryptByPublicKey("2882e099-c705-43ed-93a3-02cb2cd67559","MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAtGlTbBJzXF1fVv/+cB37QUwC5bmlm+p5KIuPIMuPX4PrhXl63R3e2bCfwhootzUdOcmmFAX6f9fWBj1Bc4lQem+FvFvE3Y53tNvGUdlNakysfXAVF8Q1PnPyGrVqiEsTHt3WMq/8vD29XJQMQ1FRvHZfY60ptypvNvvzES9JxC66RYskPHmTnerIRFzmXAJ0GUavpT3smg+K+vM5aSgfYbnuoANJTb4RMh358GTkTt4dAXRn0qpbhO+7+xbxmfOzHH9jlJ66JQr7q+W2PawNXnE4xsdwQ/1D0hT78zniTTaFyvfxBOQzx/6o1MNTZAWyhuSw7niJXUNGySJRS87OJQIDAQAB");
            Console.WriteLine(s);
        }
        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 keyBase64)
        {
            keyBase64 = keyBase64.Replace("\r", "").Replace("\n", "").Replace(" ", "");
            byte[] publicInfoByte = Convert.FromBase64String(keyBase64);
            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 keyBase64)
        {
            keyBase64 = keyBase64.Replace("\r", "").Replace("\n", "").Replace(" ", "");
            byte[] privateInfoByte = Convert.FromBase64String(keyBase64);
            // 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;
        }

        /// <summary>
        /// 私钥加密
        /// </summary>
        /// <param name="data">加密内容</param>
        /// <param name="privateKey">私钥（Base64后的）</param>
        /// <returns>返回Base64内容</returns>
    public string EncryptByPrivateKey(string data, string privateKey)
        {
            //非对称加密算法，加解密用
            IAsymmetricBlockCipher engine = new Pkcs1Encoding(new RsaEngine());

            //加密  

            try
            {
                engine.Init(true, GetPrivateKeyParameter(privateKey));
                byte[] byteData = Encoding_UTF8.GetBytes(data);
                var ResultData = engine.ProcessBlock(byteData, 0, byteData.Length);
                return Convert.ToBase64String(ResultData);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        /// <summary>
        /// 私钥解密
        /// </summary>
        /// <param name="data">待解密的内容</param>
        /// <param name="privateKey">私钥（Base64编码后的）</param>
        /// <returns>返回明文</returns>
        public string DecryptByPrivateKey(string data, string privateKey)
        {
            data = data.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, GetPrivateKeyParameter(privateKey));
                byte[] byteData = Convert.FromBase64String(data);
                var ResultData = engine.ProcessBlock(byteData, 0, byteData.Length);
                return Encoding_UTF8.GetString(ResultData);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        /// <summary>
        /// 公钥加密
        /// </summary>
        /// <param name="data">加密内容</param>
        /// <param name="publicKey">公钥（Base64编码后的）</param>
        /// <returns>返回Base64内容</returns>
        public string EncryptByPublicKey(string data, string publicKey)
        {
            //非对称加密算法，加解密用
            IAsymmetricBlockCipher engine = new Pkcs1Encoding(new RsaEngine());

            //加密
            try
            {
                engine.Init(true, GetPublicKeyParameter(publicKey));
                byte[] byteData = Encoding_UTF8.GetBytes(data);
                var ResultData = engine.ProcessBlock(byteData, 0, byteData.Length);
                return Convert.ToBase64String(ResultData);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        /// <summary>
        /// 公钥解密
        /// </summary>
        /// <param name="data">待解密的内容</param>
        /// <param name="publicKey">公钥（Base64编码后的）</param>
        /// <returns>返回明文</returns>
        public string DecryptByPublicKey(string data, string publicKey)
        {
            data = data.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(publicKey));
                byte[] byteData = Convert.FromBase64String(data);
                var ResultData = engine.ProcessBlock(byteData, 0, byteData.Length);
                return Encoding_UTF8.GetString(ResultData);

            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
    }
}