/// <summary>
/// Creates a new <see cref="MimeKit.Cryptography.MultipartSigned"/> instance with the entity as the content.
/// </summary>
/// <returns>A new <see cref="MimeKit.Cryptography.MultipartSigned"/> instance.</returns>
/// <param name="ctx">The cryptography context to use for signing.</param>
/// <param name="signer">The signer.</param>
/// <param name="digestAlgo">The digest algorithm to use for signing.</param>
/// <param name="entity">The entity to sign.</param>
/// <exception cref="System.ArgumentNullException">
/// <para><paramref name="ctx"/> is <c>null</c>.</para>
/// <para>-or-</para>
/// <para><paramref name="signer"/> is <c>null</c>.</para>
/// <para>-or-</para>
/// <para><paramref name="entity"/> is <c>null</c>.</para>
/// </exception>
/// <exception cref="CertificateNotFoundException">
/// A signing certificate could not be found for <paramref name="signer"/>.
/// </exception>
/// <exception cref="System.Security.Cryptography.CryptographicException">
/// An error occurred while signing.
/// </exception>
public static MultipartSigned Create(CryptographyContext ctx, MailboxAddress signer, DigestAlgorithm digestAlgo, MimeEntity entity)
{
if (signer == null)
{
throw new ArgumentNullException("signer");
}
if (entity == null)
{
throw new ArgumentNullException("entity");
}
PrepareEntityForSigning(entity);
using (var memory = new MemoryStream()) {
using (var filtered = new FilteredStream(memory)) {
// Note: see rfc3156, section 3 - second note
filtered.Add(new ArmoredFromFilter());
// Note: see rfc3156, section 5.4 (this is the main difference between rfc2015 and rfc3156)
filtered.Add(new TrailingWhitespaceFilter());
// Note: see rfc2015 or rfc3156, section 5.1
filtered.Add(new Unix2DosFilter());
entity.WriteTo(filtered);
filtered.Flush();
}
memory.Position = 0;
// Note: we need to parse the modified entity structure to preserve any modifications
var parser = new MimeParser(memory, MimeFormat.Entity);
var parsed = parser.ParseEntity();
memory.Position = 0;
// sign the cleartext content
var signature = ctx.Sign(signer, digestAlgo, memory);
var micalg = ctx.GetMicAlgorithmName(digestAlgo);
var signed = new MultipartSigned();
// set the protocol and micalg Content-Type parameters
signed.ContentType.Parameters["protocol"] = ctx.SignatureProtocol;
signed.ContentType.Parameters["micalg"] = micalg;
// add the modified/parsed entity as our first part
signed.Add(parsed);
// add the detached signature as the second part
signed.Add(signature);
return(signed);
}
}
/// <summary>
/// Creates a new <see cref="MimeKit.Cryptography.MultipartSigned"/> instance with the entity as the content.
/// </summary>
/// <returns>A new <see cref="MimeKit.Cryptography.MultipartSigned"/> instance.</returns>
/// <param name="ctx">The cryptography context to use for signing.</param>
/// <param name="signer">The signer.</param>
/// <param name="digestAlgo">The digest algorithm to use for signing.</param>
/// <param name="entity">The entity to sign.</param>
/// <exception cref="System.ArgumentNullException">
/// <para><paramref name="ctx"/> is <c>null</c>.</para>
/// <para>-or-</para>
/// <para><paramref name="signer"/> is <c>null</c>.</para>
/// <para>-or-</para>
/// <para><paramref name="entity"/> is <c>null</c>.</para>
/// </exception>
/// <exception cref="System.ArgumentOutOfRangeException">
/// The <paramref name="digestAlgo"/> was out of range.
/// </exception>
/// <exception cref="System.NotSupportedException">
/// The <paramref name="digestAlgo"/> is not supported.
/// </exception>
/// <exception cref="CertificateNotFoundException">
/// A signing certificate could not be found for <paramref name="signer"/>.
/// </exception>
/// <exception cref="PrivateKeyNotFoundException">
/// The private key could not be found for <paramref name="signer"/>.
/// </exception>
/// <exception cref="Org.BouncyCastle.Cms.CmsException">
/// An error occurred in the cryptographic message syntax subsystem.
/// </exception>
public static MultipartSigned Create(CryptographyContext ctx, MailboxAddress signer, DigestAlgorithm digestAlgo, MimeEntity entity)
{
if (signer == null)
throw new ArgumentNullException ("signer");
if (entity == null)
throw new ArgumentNullException ("entity");
PrepareEntityForSigning (entity);
using (var memory = new MemoryStream ()) {
using (var filtered = new FilteredStream (memory)) {
// Note: see rfc3156, section 3 - second note
filtered.Add (new ArmoredFromFilter ());
// Note: see rfc3156, section 5.4 (this is the main difference between rfc2015 and rfc3156)
filtered.Add (new TrailingWhitespaceFilter ());
// Note: see rfc2015 or rfc3156, section 5.1
filtered.Add (new Unix2DosFilter ());
entity.WriteTo (filtered);
filtered.Flush ();
}
memory.Position = 0;
// Note: we need to parse the modified entity structure to preserve any modifications
var parser = new MimeParser (memory, MimeFormat.Entity);
var parsed = parser.ParseEntity ();
memory.Position = 0;
// sign the cleartext content
var signature = ctx.Sign (signer, digestAlgo, memory);
var micalg = ctx.GetMicAlgorithmName (digestAlgo);
var signed = new MultipartSigned ();
// set the protocol and micalg Content-Type parameters
signed.ContentType.Parameters["protocol"] = ctx.SignatureProtocol;
signed.ContentType.Parameters["micalg"] = micalg;
// add the modified/parsed entity as our first part
signed.Add (parsed);
// add the detached signature as the second part
signed.Add (signature);
return signed;
}
}
