using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Security.Cryptography;

using System.Text;

using System.Threading.Tasks;

​

public class Program

{

    public static void Main()

    {

        const string publicKey = @"-----BEGIN PUBLIC KEY-----

MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwuMCKOdptWX0DBKKbHDw

XTZSiJxq3pdk97p6OUO9Rwp39RE/YYw0UDYryMbMO8Bhs5CXaXNvQHop2ljCoKtc

5o/njuWM2Y+SZhi8exG2dK1a82MCJBM9ds79UaV98R+ZgNEUVUtYuww4tdOCYWuL

PYaLo/cueEh6/fJEcirLr53S7EIY3uUOhvCo7HcGBrIvho6kEDxmsi08V5jeBNXM

QtI4Fc0mhy+ptHkBT4m6VMZxIo7dpH4RtWXpOR8PBeDbOQRMku43af0RQMpzj/nq

ZHpB6O1lIUHGaNWCEF7NE6+V1ELFS/BFlb/k1zJrou3EBoc5IZizJtFx3JLaax6v

+wIDAQAB

-----END PUBLIC KEY-----";

        RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();

        string publicKey1 = MakePem(rsa.ExportSubjectPublicKeyInfo(), "PUBLIC KEY");

        string privateKey = MakePem(rsa.ExportRSAPrivateKey(), "RSA PRIVATE KEY");

        Console.WriteLine(publicKey1);

        using var key = RSA.Create();

        try

        {

            key.ImportFromPem(publicKey);

            Console.WriteLine(key.ExportSubjectPublicKeyInfo());

//          var keyId = string.Concat(SHA256.Create().ComputeHash(key.ExportSubjectPublicKeyInfo()).Select(b => b.ToString("x2")));

//          Console.WriteLine(keyId);

        }

        catch (ArgumentException e)

        {

            Console.WriteLine(e.Message);

        }

    }

    private static string MakePem(byte[] ber, string header)

{

    StringBuilder builder = new StringBuilder("-----BEGIN ");

    builder.Append(header);

    builder.AppendLine("-----");

​

    string base64 = Convert.ToBase64String(ber);

    int offset = 0;

    const int LineLength = 64;

​

    while (offset < base64.Length)

    {

        int lineEnd = Math.Min(offset + LineLength, base64.Length);

        builder.AppendLine(base64.Substring(offset, lineEnd - offset));

        offset = lineEnd;

    }

​

    builder.Append("-----END ");

    builder.Append(header);

    builder.AppendLine("-----");

    return builder.ToString();

}

​

​

​

}