Generate public-private key pair and show them in textbox in asp.net

Question

any body can explain the parameters of RSAParameters i had seen the parameters like p,d,e,q,... i need the private key and public key from it

i got the link

http://msdn.microsoft.com/en-us/library/system.security.cryptography.rsaparameters%28v=vs.90%29.aspx[^]

i am using the sample code as like this can anybody can say it was right or not sample code:

  //Generate a public/private key pair.
            RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
            //Save the public key information to an RSAParameters structure.
            RSAParameters RSAKeyInfo = RSA.ExportParameters(true);
            //public key    
            TextBox5.Text = Convert.ToBase64String(RSAKeyInfo.Exponent);
            // private key  
            TextBox6.Text = Convert.ToBase64String(RSAKeyInfo.D);

they had give as that the public key is {e,n} where n = result of the (P*Q) Private key is {d, n} where n = result of the (P*Q)

where i had done is the correct thing or not in the sample code for the public and private keys

thanks alot

Photo

Remember that not all byte arrays can be shown as valid strings and that they don't have to survive a round trip from byte[] to string to byte[] – Jungle

The Exponent property should return an exponent like "AQAB" instead of a public key...it would make more sense in your case to have tried the Modulus property – Consolatory

Answer 1

Using the BouncyCastle API

http://www.bouncycastle.org/

and something similiar to the following:

public AsymmetricCipherKeyPair GenerateKeys(int keySizeInBits)
{
  RsaKeyPairGenerator r = new RsaKeyPairGenerator();
  r.Init(new KeyGenerationParameters(new SecureRandom(),
    keySizeInBits));
  AsymmetricCipherKeyPair keys = r.GenerateKeyPair();
  return keys;
}

You can access an object that will have a .Public and .Private property with the correctly formatted strings.

I had a similiar problem a while back and this was the best solution that I could find. I do not have the exact code to hand, but will post it when I get into the office if required, but the above should work.

Updated with Code

This is the code I used to generate public/private keys.

  using Org.BouncyCastle.Crypto;
  using Org.BouncyCastle.Crypto.Generators;
  using Org.BouncyCastle.Security;

  public static AsymmetricCipherKeyPair GenerateKeys(int keySizeInBits)
    {
        var r = new RsaKeyPairGenerator();
        r.Init(new KeyGenerationParameters(new SecureRandom(),keySizeInBits));
        var keys = r.GenerateKeyPair();
        return keys;
    }



static void Main(string[] args)
{
    var keys = GenerateKeys(2048);


    var publicKey = keys.Public.ToString();

    var textWriter = new StreamWriter("private.key");
    var pemWriter = new PemWriter(textWriter);
    pemWriter.WriteObject(keys.Private);
    pemWriter.Writer.Flush();
    textWriter.Close();


    textWriter = new StreamWriter("public.key");
    pemWriter = new PemWriter(textWriter);
    pemWriter.WriteObject(keys.Public);
    pemWriter.Writer.Flush();
    textWriter.Close();

    Console.ReadKey();


}

Labourer

when I view var "publicKey" I see "Org.BouncyCastle.Crypto.Parameters.RsaKeyParameters". Is this expected? – Importation