Question

我正在开发一个项目，我需要使用“公钥”来使用RSA算法加密消息。我获得了证书，我的第一个想法是使用该证书中的公钥，经过调查后我了解到我需要使用RSACryptoServiceProvider进行加密。

我检查了msdn，我认为应该使用的方法是RSACryptoServiceProvider.ImportCspBlob(byte[] keyBlob)。当我尝试使用从证书导出的公钥时，我收到的错误是证书的标头数据无效。

我知道我可以将X509certificate2.PublicKey.Key投射到RSACryptoServiceProvider但是从我对客户的理解是，我将继续只获得公钥，而不是证书。此密钥必须保存在.xml配置文件中。

总结一下：有没有办法在只给出证书的公钥的情况下生成RSACryptoServiceProvider？

Answer 1

您可以尝试查看此示例：RSA public key encryption in C#

var publicKey = "<RSAKeyValue><Modulus>21wEnTU+mcD2w0Lfo1Gv4rtcSWsQJQTNa6gio05AOkV/Er9w3Y13Ddo5wGtjJ19402S71HUeN0vbKILLJdRSES5MHSdJPSVrOqdrll/vLXxDxWs/U0UT1c8u6k/Ogx9hTtZxYwoeYqdhDblof3E75d9n2F0Zvf6iTb4cI7j6fMs=</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";

var testData = Encoding.UTF8.GetBytes("testing");

using ( var rsa = new RSACryptoServiceProvider(1024))
{
    try
    {
        // client encrypting data with public key issued by server
        //
        rsa.FromXmlString(publicKey);
        var encryptedData = rsa.Encrypt(testData, true);

        var base64Encrypted = Convert.ToBase64String(encryptedData);

    }
    finally
    {
        rsa.PersistKeyInCsp = false;
    }
}

Answer 2

你没事，遵循一个很好的典型模式。数据的发件人不需要私钥。

以下内容可能会确认您已经找到的一些代码。我设置了接收器/解码器私钥的一行我遗漏了。我从我在构建部署中的测试用例中获取了这个。

 byte[] certBytAr;  // This is the certificate as bianry in a .cer file (no  private key in it - public only) 

 X509Certificate2 cert2 = new X509Certificate2(certBytAr);


 string strToEncrypt = "Public To Private Test StackOverFlow PsudeoCode. Surfs Up at Secret Beach.";
 byte[] bytArToEncrypt = Encoding.UTF8.GetBytes(strToEncrypt);

 RSACryptoServiceProvider rsaEncryptor = (RSACryptoServiceProvider)cert2.PublicKey.Key; 

 byte[] dataNowEncryptedArray = rsaEncryptor.Encrypt(bytArToEncrypt, true);

 // done - you now have encrypted bytes 
 // 

  // somewhere elxe ...
 // this should decrpyt it - simulate the destination which will decrypt the data with the private key 

 RSACryptoServiceProvider pk =   // how this is set is complicated 

 // set the private key in the x509 oobject we created way above 
 cert2.PrivateKey = pk; 

 RSACryptoServiceProvider rsaDecryptor = (RSACryptoServiceProvider)cert2.PrivateKey;
 byte[] dataDecrypted = rsaDecryptor.Decrypt(dataNowEncryptedArray, true);

 Console.WriteLine(" encrypt 1 Way Intermediate " + BitConverter.ToString(dataDecrypted));

 string strDecodedFinal = Encoding.UTF8.GetString(dataDecrypted);

 if (strDecodedFinal == strToEncrypt)
 {

 }
 else
 {
     Console.WriteLine(" FAILURE OF  ENCRYPTION ROUND TRIP IN SIMPLE TEST (Direction: Public to Private). No Surfing For You ");
  }

从公钥（不是证书）构造RSACryptoServiceProvider

2 个答案: