LoadCertificate.cs

using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.OpenSsl;
using Org.BouncyCastle.Pkcs;
using Org.BouncyCastle.Security;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using X509Certificate = Org.BouncyCastle.X509.X509Certificate;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;

 private X509Certificate2 LoadCertificate()
        {
            var sslKey = Environment.GetEnvironmentVariable("SSL_KEY");
            var sslCertficate = Environment.GetEnvironmentVariable("SSL_CERTIFICATE");
            var keyBytes = Convert.FromBase64String(sslKey);
            var crtBytes = Convert.FromBase64String(sslCertficate);

            var pkcs12Store = new Pkcs12Store();
            var pr1 = new PemReader(new StringReader(Encoding.UTF8.GetString(crtBytes)));
            var cert = (X509Certificate) pr1.ReadObject();
            var certEntry = new X509CertificateEntry(cert);
            pkcs12Store.SetCertificateEntry("", certEntry);
            var pr = new PemReader(new StringReader(Encoding.UTF8.GetString(keyBytes)));
            var kp = (AsymmetricCipherKeyPair) pr.ReadObject();
            pkcs12Store.SetKeyEntry("", new AsymmetricKeyEntry(kp.Private), new[] {certEntry});
            using (var pfxStream = new MemoryStream())
            {
                pkcs12Store.Save(pfxStream, "".ToCharArray(), new SecureRandom());
                pfxStream.Seek(0, SeekOrigin.Begin);
                return new X509Certificate2(pfxStream.ToArray());
            }
        }