MimeKit.Cryptography.CmsSigner.LoadPkcs12 C# (CSharp) Method

		void LoadPkcs12 (Stream stream, string password)
		{
			var pkcs12 = new Pkcs12Store (stream, password.ToCharArray ());

			foreach (string alias in pkcs12.Aliases) {
				if (!pkcs12.IsKeyEntry (alias))
					continue;

				var chain = pkcs12.GetCertificateChain (alias);
				var key = pkcs12.GetKey (alias);

				if (!key.Key.IsPrivate || chain.Length == 0)
					continue;

				var flags = chain[0].Certificate.GetKeyUsageFlags ();

				if (flags != X509KeyUsageFlags.None && (flags & SecureMimeContext.DigitalSignatureKeyUsageFlags) == 0)
					continue;

				CheckCertificateCanBeUsedForSigning (chain[0].Certificate);

				CertificateChain = new X509CertificateChain ();
				Certificate = chain[0].Certificate;
				PrivateKey = key.Key;

				foreach (var entry in chain)
					CertificateChain.Add (entry.Certificate);

				break;
			}

			if (PrivateKey == null)
				throw new ArgumentException ("The stream did not contain a private key.", "stream");
		}