在C#中保存Bouncy Castle生成的密钥对

在用Bouncy Castle的C#版API产生公钥和私钥 中产生了一对密钥对，可以用bouncy caslte提供的API进行保存

公钥方面的3个类，具体代码根据命名空间自行查看其源代码：

Org.BouncyCastle.Asn1.X509 . SubjectPublicKeyInfo

Org.BouncyCastle.X509 . SubjectPublicKeyInfoFactory  

Org.BouncyCastle.Security . PublicKeyFactory

 

用法：

SubjectPublicKeyInfo subInfo = SubjectPublicKeyInfoFactory .CreateSubjectPublicKeyInfo(rsaPublic);

//rsaPublic是产生的公钥，类型是AsymmetricKeyParameter/RsaKeyParameters，其中后者集成前者

AsymmetricKeyParameter testpublicKey = (RsaKeyParameters)PublicKeyFactory. CreateKey(subInfo);

私钥方面，但私钥保存到本地文件中时，可以选择加密保存，3DES with sha1，涉及到5个类：

Org.BouncyCastle.Asn1.Pkcs . PrivateKeyInfo

Org.BouncyCastle.Pkcs . PrivateKeyInfoFactory

Org.BouncyCastle.Security . PrivateKeyFactory

Org.BouncyCastle.Asn1.Pkcs . EncryptedPrivateKeyInfo

Org.BouncyCastle.Pkcs . EncryptedPrivateKeyInfoFactory

前面3个类的用法同上面公钥的类似：

PrivateKeyInfo privInfo = PrivateKeyInfoFactory .CreatePrivateKeyInfo(rsaPrivate);

AsymmetricKeyParameter testResult = (RsaPrivateCrtKeyParameters) PrivateKeyFactory .CreateKey(privInfo);

如果要加密保存私钥的话：

string alg = "1.2.840.113549.1.12.1.3"; // 3 key triple DES with SHA-1
byte[] salt = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
int count=1000;
char[] password="123456".ToCharArray();
EncryptedPrivateKeyInfo enPrivateKeyInfo = EncryptedPrivateKeyInfoFactory .CreateEncryptedPrivateKeyInfo(
    alg,
    password,
    salt,
    count,
    privateKey);

从EncryptedPrivateKeyInfo 恢复出PrivateKeyInfo 则简单多了：

PrivateKeyInfo priInfo = PrivateKeyInfoFactory .CreatePrivateKeyInfo(password, enPrivateKeyInfo);

再导出私钥：

AsymmetricKeyParameter privateKey = PrivateKeyFactory .CreateKey(priInfo);

 

SubjectPublicKeyInfo和PrivateKeyInfo都提供了ToAsn1Object()方法，转换成很Asn1Object，再使用GetEncoded()方法，生成byte数组，然后保存到本地。编码是BER，当然DER也是可以。从本地读取文件时逆过程即可，把读取到的byte数组转换成Asn1Object对象，再使用GetInstance()方法。

 

测试代码：

using System; using System.Collections.Generic; using System.Collections; using System.Text; using System.Security.Cryptography; using System.Security.Cryptography.X509Certificates; // X509Certificate2 using System.IO; 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(); using Org.BouncyCastle.Math; using Org.BouncyCastle.Asn1.X509; //X509Name using Org.BouncyCastle.X509; using Org.BouncyCastle.Utilities.Collections; //X509V3CertificateGenerator using Org.BouncyCastle.Asn1.Pkcs; //PrivateKeyInfo using Org.BouncyCastle.Pkcs; using Org.BouncyCastle.Asn1; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { //公钥和密钥的生成，并加密解密测试 RsaKeyGeneratorTest(); //done!!!!! } private static void RsaKeyGeneratorTest() { //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(); //获取公钥和私钥 AsymmetricKeyParameter publicKey = keyPair.Public; AsymmetricKeyParameter privateKey = keyPair.Private; if (((RsaKeyParameters)publicKey).Modulus.BitLength < 1024) { Console.WriteLine("failed key generation (1024) length test"); } savetheKey(publicKey, privateKey); //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); //非对称加密算法，加解密用 IAsymmetricBlockCipher engine = new RsaEngine(); //公钥加密 //从保存在本地的磁盘文件中读取公钥 Asn1Object aobject = Asn1Object.FromStream(new FileStream(@"E:/Desktop/a.pub",FileMode.Open,FileAccess.Read)); //a.puk?? SubjectPublicKeyInfo pubInfo = SubjectPublicKeyInfo.GetInstance(aobject); AsymmetricKeyParameter testpublicKey = (RsaKeyParameters)PublicKeyFactory.CreateKey(pubInfo); FileStream fs; engine.Init(true, testpublicKey); try { //Console.WriteLine("加密前:" + Convert.ToBase64String(testData) + Environment.NewLine); testData = engine.ProcessBlock(testData, 0, testData.Length); Console.WriteLine("加密完成！" + Environment.NewLine); fs = new FileStream(@"E:/Desktop/encryptedBytes", FileMode.Create, FileAccess.Write); fs.Write(testData, 0, testData.Length); fs.Close(); Console.WriteLine("保存密文成功" + Environment.NewLine); } catch (Exception ex) { Console.WriteLine("failed - exception " + Environment.NewLine + ex.ToString()); } //私钥解密 //获取加密的私钥，进行解密，获得私钥 fs = new FileStream(@"E:/Desktop/encryptedBytes", FileMode.Open, FileAccess.Read); byte[] anothertestdata = new byte[1024]; fs.Read(anothertestdata, 0, anothertestdata.Length); fs.Close(); Asn1Object aobj = Asn1Object.FromStream(new FileStream(@"E:/Desktop/a.pri", FileMode.Open, FileAccess.Read)); //a.pvk?? EncryptedPrivateKeyInfo enpri = EncryptedPrivateKeyInfo.GetInstance(aobj); char[] password = "123456".ToCharArray(); PrivateKeyInfo priKey = PrivateKeyInfoFactory.CreatePrivateKeyInfo(password, enpri); //解密 AsymmetricKeyParameter anotherprivateKey = PrivateKeyFactory.CreateKey(priKey); //私钥 engine.Init(false, anotherprivateKey); try { anothertestdata = engine.ProcessBlock(anothertestdata, 0, testData.Length); Console.WriteLine("解密后密文为：" + Encoding.UTF8.GetString(anothertestdata) + Environment.NewLine); } catch (Exception e) { Console.WriteLine("failed - exception " + e.ToString()); } Console.Read(); } private static void savetheKey(AsymmetricKeyParameter publicKey, AsymmetricKeyParameter privateKey) { //保存公钥到文件 SubjectPublicKeyInfo publicKeyInfo = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(publicKey); Asn1Object aobject = publicKeyInfo.ToAsn1Object(); byte[] pubInfoByte = aobject.GetEncoded(); FileStream fs = new FileStream(@"E:/Desktop/a.pub", FileMode.Create, FileAccess.Write); fs.Write(pubInfoByte, 0, pubInfoByte.Length); fs.Close(); //保存私钥到文件 /* PrivateKeyInfo privateKeyInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(privateKey); aobject = privateKeyInfo.ToAsn1Object(); byte[] priInfoByte = aobject.GetEncoded(); fs = new FileStream(@"E:/Desktop/a.pri", FileMode.Create, FileAccess.Write); fs.Write(priInfoByte, 0, priInfoByte.Length); fs.Close(); */ string alg = "1.2.840.113549.1.12.1.3"; // 3 key triple DES with SHA-1 byte[] salt = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; int count=1000; char[] password="123456".ToCharArray(); EncryptedPrivateKeyInfo enPrivateKeyInfo = EncryptedPrivateKeyInfoFactory.CreateEncryptedPrivateKeyInfo( alg, password, salt, count, privateKey); byte[] priInfoByte = enPrivateKeyInfo.ToAsn1Object().GetEncoded(); fs = new FileStream(@"E:/Desktop/a.pri", FileMode.Create, FileAccess.Write); fs.Write(priInfoByte, 0, priInfoByte.Length); fs.Close(); //还原 //PrivateKeyInfo priInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(password, enPrivateKeyInfo); //AsymmetricKeyParameter privateKey = PrivateKeyFactory.CreateKey(priInfoByte); } } }

 

接下来就可以生成cer公钥证书或者pfx证书