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

		static void CheckCertificateCanBeUsedForSigning (X509Certificate certificate)
		{
			var flags = certificate.GetKeyUsageFlags ();

			if (flags != X509KeyUsageFlags.None && (flags & SecureMimeContext.DigitalSignatureKeyUsageFlags) == 0)
				throw new ArgumentException ("The certificate cannot be used for signing.");
		}