-----BEGIN CERTIFICATE-----

MIIGsTCCBJmgAwIBAgIUXW/MFYI8s1FZkryqXsR1lWMtUwkwDQYJKoZIhvcNAQELBQAwgc4xCzAJBgNVBAYTAktaMRUwEwYDVQQHDAzQkNCh0KLQkNCd0JAxFTATBgNVBAgMDNCQ0KHQotCQ0J3QkDFM

                                   ...................................................................											

Rj79HRvU36WE9hbfkb7b/hvctLlRVA8c5o0G/khwBc1QTS2tJzKbTQourVO7cnu4BvE1glXa3vsU6H6dSfLh7jyTAO5gX3OiJZEB7dLYlxYwlAcPI5ytLnOnzsrZLEKMuEyPPS6zoSwmP6Sx+L7P7mug

VYoUZHqQkw==
-----END CERTIFICATE-----

//var certificate = new System.Security.Cryptography.X509Certificates.X509Certificate2(@"D:\Temp\keys\GOSTKNCA_f8a422238209b6e753116431b69b09178f14e9d7.p12", "Qwerty12", X509KeyStorageFlags.Exportable);

var certificate = new System.Security.Cryptography.X509Certificates.X509Certificate2(@"D:\Temp\keys\AUTH_RSA256_67c361bcf2cb136282ebb1a45c7acb21636225df.p12", "Qwerty12", X509KeyStorageFlags.Exportable);

        StringBuilder builder = new StringBuilder();

        builder.AppendLine("-----BEGIN CERTIFICATE-----");
        builder.AppendLine(Convert.ToBase64String(certificate.Export(X509ContentType.Pkcs12, "Qwerty12"), Base64FormattingOptions.InsertLineBreaks));
        builder.AppendLine("-----END CERTIFICATE-----");

        Console.WriteLine(builder);
        Console.ReadLine();