/// <summary>
/// Gets signed mime content. Value null means no content.
/// </summary>
/// <returns>Returns signed mime content. Value null means no content.</returns>
/// <remarks>This method is valid only if <b>Content-Type</b> parameter <b>smime-type=signed-data</b>.</remarks>
/// <exception cref="InvalidOperationException">Is raised when <b>smime-type != signed-data</b>.</exception>
public MIME_Message GetSignedMime()
{
if (!string.Equals(this.Entity.ContentType.Parameters["smime-type"], "signed-data", StringComparison.InvariantCultureIgnoreCase))
{
throw new InvalidOperationException("The VerifySignature method is only valid if Content-Type parameter smime-type=signed-data.");
}
if (this.Data != null)
{
SignedCms signedCms = new SignedCms();
signedCms.Decode(this.Data);
return(MIME_Message.ParseFromStream(new MemoryStream(signedCms.ContentInfo.Content)));
}
else
{
return(null);
}
}
/// <summary>
/// Decrypts enveloped mime content.
/// </summary>
/// <param name="cert">Decrypting certificate.</param>
/// <returns>Returns decrypted enveloped mime content.</returns>
/// <exception cref="ArgumentNullException">Is raised when <b>cert</b> is null reference.</exception>
/// <exception cref="InvalidOperationException">Is raised when <b>smime-type != enveloped-data</b>.</exception>
public MIME_Message GetEnvelopedMime(X509Certificate2 cert)
{
if (cert == null)
{
throw new ArgumentNullException("cert");
}
if (!string.Equals(this.Entity.ContentType.Parameters["smime-type"], "enveloped-data", StringComparison.InvariantCultureIgnoreCase))
{
throw new InvalidOperationException("The VerifySignature method is only valid if Content-Type parameter smime-type=enveloped-data.");
}
EnvelopedCms envelopedCms = new EnvelopedCms();
envelopedCms.Decode(this.Data);
X509Certificate2Collection certificates = new X509Certificate2Collection(cert);
envelopedCms.Decrypt(certificates);
return(MIME_Message.ParseFromStream(new MemoryStream(envelopedCms.Encode())));
}