用Bouncy Castle的C#版API产生公钥和私钥 如何保存成文件与加载

[cqhydz]

搞了几天都没有有完成，求助一下
网上找到的例了，这个算简单的一个，代码能跑，但问题是 这里面的key怎么导出成文件，还有使用时怎么载入，没搞明白，有哪位搞过这方面的指导一下。

http://blog.csdn.net/popozhu/article/details/5789382

using System;
using System.Collections.Generic;
using System.Text;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Crypto.Engines;  //IAsymmetricBlockCipher engine = new RsaEngine();
namespace ConsoleApplication1
{
    class Program
    { 
        static void Main(string[] args)
        {
            //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;
            if( ((RsaKeyParameters)publicKey).Modulus.BitLength<1024 )
            {
                Console.WriteLine("failed key generation (1024) length test");                
            }
            //一个测试……………………
            //输入，十六进制的字符串，解码为byte[]
            //string input = "4e6f77206973207468652074696d6520666f7220616c6c20676f6f64206d656e";
            //byte[] testData = Org.BouncyCastle.Utilities.Encoders.Hex.Decode(input);           
            string input = "popozh RSA test";
            byte[] testData = Encoding.UTF8.GetBytes(input);
            Console.WriteLine("明文:" + input + Environment.NewLine);
            //非对称加密算法，加解密用
            IAsymmetricBlockCipher engine = new RsaEngine();
            //公钥加密
            engine.Init(true, publicKey);
            try
            {
                testData = engine.ProcessBlock(testData, 0, testData.Length);               
                Console.WriteLine("密文（base64编码）:" + Convert.ToBase64String(testData) + Environment.NewLine);
            }
            catch (Exception ex)
            {
                Console.WriteLine("failed - exception " + Environment.NewLine + ex.ToString());
            }
            //私钥解密
            engine.Init(false, privateKey);
            try
            {
                testData = engine.ProcessBlock(testData, 0, testData.Length);
   
            }
            catch (Exception e)
            {
                Console.WriteLine("failed - exception " + e.ToString());
            }
            if (input.Equals(Encoding.UTF8.GetString(testData)))
            {
                Console.WriteLine("解密成功");
            }
            Console.Read();
        }
    }
}

[cqhydz]

这个作者还写了个后篇，只是保存16进制DER编码格式，而非常见的pem字符串或xml字符串格式，没法用。

[Forty2]

写Pem字符串比较容易，用Org.BouncyCastle.OpenSsl.PemWriter就可以了。格式类似以下的例子：

static void Main(string[] args)
{
    string pem =
        @"-----BEGIN RSA PRIVATE KEY-----
        MIICWwIBAAKBgQCuvrDVWxG0GA3vL8WBeHLS/eH49evvEc/+9cqdNUASeK++O/Ha
        L/BFzNY3EXm7Q0fZaQybp7sUZAS1XY3ySljJFRmNQBcyyVdEe4FUpLnoiO5Je5/v
        3Ok8cSyC6lTjYfM5XDNbPpIP12+rFGtmgsnHLobk/vgoR99OEcVFVkbgDQIBEQKB
        gQCkdz0FCmsD2md3tH2nB/OZZ2tEqzhoiTw7Qa+jBPECU3g6ksWCDwBBsbqOLpCw
        P1KugPzOu/tefECqsmd6oFOOg6Z0+ZZ5pJU6yuGIPW9eQ0WjSQJVmQE57fUZnsP2
        xGIwGL8/99jWHEncJL/o+0oOP9jcZ31zPajc8Pqo76M88QJBAOpCMmW89DtLcneq
        rOyndg6vmo8KKpNKVg1lMCOLDOBrqtyRHOL/n7nWmX6e1y0mc5ZBW0RBbVl6Ur8Q
        EoS1QdECQQC+9n6RKl1PLUOMRwb2zB5SxLFvA0pXDZjW8ueOGaBQ3ztlVwpkPAyf
        ipeuwKfKpKR0bx+MwXB84ZCSqt9S9C19AkEAwOs4kAUFXgHly/X30fNSKjZDDGK5
        pnl0CwgJhq6/T2e54tHbjcN0euz24L8Ljpgi9DXSsK5aDXPLrGeWx6RUUQJAe5Bw
        A5PiBg46xC31coQTnve+GqfGsMyQEp0sawGF2fnbI3SOQNuPsobankBski5MS1b2
        TASyMrASQMjq21K0BQJAEx/dAjP9NtN7x4WJylhtY9RZPAeqDRxHKYNiLTOWB03L
        dCzFm4VLgHjXRkmeuQ/MWmNR/XhXChXh1PWKSrCJmQ==
        -----END RSA PRIVATE KEY-----";
    AsymmetricCipherKeyPair pair = ReadPem(pem);

    var rsa = new RsaEngine();
    rsa.Init(true, pair.Public);
    byte[] encrypted = rsa.ProcessBlock(Encoding.UTF8.GetBytes("hello"), 0, 5);
    rsa.Init(false, pair.Private);
    string decrypted = Encoding.UTF8.GetString(rsa.ProcessBlock(encrypted, 0, encrypted.Length)); // hello

}

static string WritePem(AsymmetricCipherKeyPair pair)
{
    using (TextWriter textWriter = new StringWriter())
    {
        var pemWriter = new Org.BouncyCastle.OpenSsl.PemWriter(textWriter);
        pemWriter.WriteObject(pair.Private);
        return textWriter.ToString();
    }
}

static AsymmetricCipherKeyPair ReadPem(string pem)
{
    using(TextReader reader = new StringReader(pem))
    {
        var obj = new Org.BouncyCastle.OpenSsl.PemReader(reader).ReadObject();
        return obj as AsymmetricCipherKeyPair;
    }
}

[cqhydz]

引用 2 楼 Forty2 的回复:

写Pem字符串比较容易，用Org.BouncyCastle.OpenSsl.PemWriter就可以了。格式类似以下的例子：

static void Main(string[] args)
{
    string pem =
        @"-----BEGIN RSA PRIVATE KEY-----
        MIICWwIBAAKBgQCuvrDVWxG0GA3vL8WBeHLS/eH49evvEc/+9cqdNUASeK++O/Ha
        L/BFzNY3EXm7Q0fZaQybp7sUZAS1XY3ySljJFRmNQBcyyVdEe4FUpLnoiO5Je5/v
        3Ok8cSyC6lTjYfM5XDNbPpIP12+rFGtmgsnHLobk/vgoR99OEcVFVkbgDQIBEQKB
        gQCkdz0FCmsD2md3tH2nB/OZZ2tEqzhoiTw7Qa+jBPECU3g6ksWCDwBBsbqOLpCw
        P1KugPzOu/tefECqsmd6oFOOg6Z0+ZZ5pJU6yuGIPW9eQ0WjSQJVmQE57fUZnsP2
        xGIwGL8/99jWHEncJL/o+0oOP9jcZ31zPajc8Pqo76M88QJBAOpCMmW89DtLcneq
        rOyndg6vmo8KKpNKVg1lMCOLDOBrqtyRHOL/n7nWmX6e1y0mc5ZBW0RBbVl6Ur8Q
        EoS1QdECQQC+9n6RKl1PLUOMRwb2zB5SxLFvA0pXDZjW8ueOGaBQ3ztlVwpkPAyf
        ipeuwKfKpKR0bx+MwXB84ZCSqt9S9C19AkEAwOs4kAUFXgHly/X30fNSKjZDDGK5
        pnl0CwgJhq6/T2e54tHbjcN0euz24L8Ljpgi9DXSsK5aDXPLrGeWx6RUUQJAe5Bw
        A5PiBg46xC31coQTnve+GqfGsMyQEp0sawGF2fnbI3SOQNuPsobankBski5MS1b2
        TASyMrASQMjq21K0BQJAEx/dAjP9NtN7x4WJylhtY9RZPAeqDRxHKYNiLTOWB03L
        dCzFm4VLgHjXRkmeuQ/MWmNR/XhXChXh1PWKSrCJmQ==
        -----END RSA PRIVATE KEY-----";
    AsymmetricCipherKeyPair pair = ReadPem(pem);

    var rsa = new RsaEngine();
    rsa.Init(true, pair.Public);
    byte[] encrypted = rsa.ProcessBlock(Encoding.UTF8.GetBytes("hello"), 0, 5);
    rsa.Init(false, pair.Private);
    string decrypted = Encoding.UTF8.GetString(rsa.ProcessBlock(encrypted, 0, encrypted.Length)); // hello

}

static string WritePem(AsymmetricCipherKeyPair pair)
{
    using (TextWriter textWriter = new StringWriter())
    {
        var pemWriter = new Org.BouncyCastle.OpenSsl.PemWriter(textWriter);
        pemWriter.WriteObject(pair.Private);
        return textWriter.ToString();
    }
}

static AsymmetricCipherKeyPair ReadPem(string pem)
{
    using(TextReader reader = new StringReader(pem))
    {
        var obj = new Org.BouncyCastle.OpenSsl.PemReader(reader).ReadObject();
        return obj as AsymmetricCipherKeyPair;
    }
}

这里不是应用，而是 //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); 生成密钥后如何生成pem 格式数据导出成pem文件，而不是用openssl生成。

[Forty2]

// ... 你的代码 //产生密钥对 AsymmetricCipherKeyPair keyPair = keyGenerator.GenerateKeyPair(); // 我提供的例子就有WritePem： string pem = WritePem(keyPair); File.WriteAllText("文件名", pem);