RSA客戶端服務器加密解密

Question

這是一個簡單的RSA encryption/decryption代碼。

如何使其適用於不同的應用程序？ 在以下示例中，相同的RSA對象用於加密和解密。 如何使其適用於2個單獨的應用程序。 因此，在一個應用程序中加密的數據將被其他應用程序解密。

using System;
using System.Security.Cryptography;
using System.Text;

class RSACSPSample
{

    static void Main()
    {
        try
        {
            //Create a UnicodeEncoder to convert between byte array and string.
            UnicodeEncoding ByteConverter = new UnicodeEncoding();

            //Create byte arrays to hold original, encrypted, and decrypted data. 
            byte[] dataToEncrypt = ByteConverter.GetBytes("Data to Encrypt");
            byte[] encryptedData;
            byte[] decryptedData;

            //Create a new instance of RSACryptoServiceProvider to generate 
            //public and private key data. 
            using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider())
            {

                //Pass the data to ENCRYPT, the public key information  
                //(using RSACryptoServiceProvider.ExportParameters(false), 
                //and a boolean flag specifying no OAEP padding.
                encryptedData = RSAEncrypt(dataToEncrypt, RSA.ExportParameters(false), false);

                //Pass the data to DECRYPT, the private key information  
                //(using RSACryptoServiceProvider.ExportParameters(true), 
                //and a boolean flag specifying no OAEP padding.
                decryptedData = RSADecrypt(encryptedData, RSA.ExportParameters(true), false);

                //Display the decrypted plaintext to the console. 
                Console.WriteLine("Decrypted plaintext: {0}", ByteConverter.GetString(decryptedData));
            }
        }
        catch (ArgumentNullException)
        {
            //Catch this exception in case the encryption did 
            //not succeed.
            Console.WriteLine("Encryption failed.");

        }
    }

    static public byte[] RSAEncrypt(byte[] DataToEncrypt, RSAParameters RSAKeyInfo, bool DoOAEPPadding)
    {
        try
        {
            byte[] encryptedData;
            //Create a new instance of RSACryptoServiceProvider. 
            using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider())
            {

                //Import the RSA Key information. This only needs 
                //toinclude the public key information.
                RSA.ImportParameters(RSAKeyInfo);

                //Encrypt the passed byte array and specify OAEP padding.   
                //OAEP padding is only available on Microsoft Windows XP or 
                //later.  
                encryptedData = RSA.Encrypt(DataToEncrypt, DoOAEPPadding);
            }
            return encryptedData;
        }
        //Catch and display a CryptographicException   
        //to the console. 
        catch (CryptographicException e)
        {
            Console.WriteLine(e.Message);

            return null;
        }

    }

    static public byte[] RSADecrypt(byte[] DataToDecrypt, RSAParameters RSAKeyInfo, bool DoOAEPPadding)
    {
        try
        {
            byte[] decryptedData;
            //Create a new instance of RSACryptoServiceProvider. 
            using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider())
            {
                //Import the RSA Key information. This needs 
                //to include the private key information.
                RSA.ImportParameters(RSAKeyInfo);

                //Decrypt the passed byte array and specify OAEP padding.   
                //OAEP padding is only available on Microsoft Windows XP or 
                //later.  
                decryptedData = RSA.Decrypt(DataToDecrypt, DoOAEPPadding);
            }
            return decryptedData;
        }
        //Catch and display a CryptographicException   
        //to the console. 
        catch (CryptographicException e)
        {
            Console.WriteLine(e.ToString());

            return null;
        }

    }
}

Answer 1

你打電話時

//Create a new instance of RSACryptoServiceProvider to generate 
//public and private key data. 
using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider())
....

生成新的RSA密鑰對，如您在代碼上方的注釋中所述。 您需要分享此密鑰對。 你可以做到

RSA.ExportParameters(true)

要么

RSA.ToXmlString(true)

然后，您可以將此輸出包含在兩個應用程序的配置中，並且在執行開始時，您必須調用RSA.ImportParameters或RSA.FromXmlString。

請注意，上面的代碼提取了密鑰對的私有部分。 如果您只想在應用程序A中加密並且只在應用程序B中解密，那么應用程序A只需要密鑰對的公共部分，而應用程序B只需要私有部分。

另請注意，不建議通過非對稱加密技術加密大數據（出於性能原因），您應該考慮使用對稱加密（即AES256）。