/// <summary>
/// Decrypts the <see cref="MultipartEncrypted"/> part.
/// </summary>
/// <remarks>
/// Decrypts the <see cref="MultipartEncrypted"/> and extracts any digital signatures in cases
/// where the content was also signed.
/// </remarks>
/// <returns>The decrypted entity.</returns>
/// <param name="ctx">The OpenPGP cryptography context to use for decrypting.</param>
/// <param name="signatures">A list of digital signatures if the data was both signed and encrypted.</param>
/// <exception cref="System.ArgumentNullException">
/// <paramref name="ctx"/> is <c>null</c>.
/// </exception>
/// <exception cref="System.FormatException">
/// <para>The <c>protocol</c> parameter was not specified.</para>
/// <para>-or-</para>
/// <para>The multipart is malformed in some way.</para>
/// </exception>
/// <exception cref="System.NotSupportedException">
/// The provided <see cref="OpenPgpContext"/> does not support the protocol parameter.
/// </exception>
/// <exception cref="PrivateKeyNotFoundException">
/// The private key could not be found to decrypt the encrypted data.
/// </exception>
/// <exception cref="System.OperationCanceledException">
/// The user chose to cancel the password prompt.
/// </exception>
/// <exception cref="System.UnauthorizedAccessException">
/// 3 bad attempts were made to unlock the secret key.
/// </exception>
public MimeEntity Decrypt(OpenPgpContext ctx, out DigitalSignatureCollection signatures)
{
if (ctx == null)
{
throw new ArgumentNullException("ctx");
}
var protocol = ContentType.Parameters["protocol"];
if (string.IsNullOrEmpty(protocol))
{
throw new FormatException();
}
protocol = protocol.Trim().ToLowerInvariant();
if (!ctx.Supports(protocol))
{
throw new NotSupportedException();
}
if (Count < 2)
{
throw new FormatException();
}
var version = this[0] as MimePart;
if (version == null)
{
throw new FormatException();
}
var ctype = version.ContentType;
var value = string.Format("{0}/{1}", ctype.MediaType, ctype.MediaSubtype);
if (value.ToLowerInvariant() != protocol)
{
throw new FormatException();
}
var encrypted = this[1] as MimePart;
if (encrypted == null || encrypted.ContentObject == null)
{
throw new FormatException();
}
if (!encrypted.ContentType.Matches("application", "octet-stream"))
{
throw new FormatException();
}
using (var memory = new MemoryBlockStream()) {
encrypted.ContentObject.DecodeTo(memory);
memory.Position = 0;
return(ctx.Decrypt(memory, out signatures));
}
}
/// <summary> /// Verify the digital signatures of the specified signed data and extract the original content. /// </summary> /// <remarks> /// Verifies the digital signatures of the specified signed data and extracts the original content. /// </remarks> /// <returns>The extracted content stream.</returns> /// <param name="signedData">The signed data.</param> /// <param name="signatures">The digital signatures.</param> /// <param name="cancellationToken">The cancellation token.</param> /// <exception cref="System.ArgumentNullException"> /// <paramref name="signedData"/> is <c>null</c>. /// </exception> /// <exception cref="Org.BouncyCastle.Cms.CmsException"> /// An error occurred in the cryptographic message syntax subsystem. /// </exception> /// <exception cref="System.OperationCanceledException"> /// The operation was cancelled via the cancellation token. /// </exception> public abstract Stream Verify(Stream signedData, out DigitalSignatureCollection signatures, CancellationToken cancellationToken = default(CancellationToken));
/// <summary>
/// Decrypts the <see cref="MultipartEncrypted"/> part.
/// </summary>
/// <remarks>
/// Decrypts the <see cref="MultipartEncrypted"/> and extracts any digital signatures in cases
/// where the content was also signed.
/// </remarks>
/// <returns>The decrypted entity.</returns>
/// <param name="signatures">A list of digital signatures if the data was both signed and encrypted.</param>
/// <exception cref="System.FormatException">
/// <para>The <c>protocol</c> parameter was not specified.</para>
/// <para>-or-</para>
/// <para>The multipart is malformed in some way.</para>
/// </exception>
/// <exception cref="System.NotSupportedException">
/// A suitable <see cref="MimeKit.Cryptography.CryptographyContext"/> for
/// decrypting could not be found.
/// </exception>
/// <exception cref="PrivateKeyNotFoundException">
/// The private key could not be found to decrypt the encrypted data.
/// </exception>
/// <exception cref="System.OperationCanceledException">
/// The user chose to cancel the password prompt.
/// </exception>
/// <exception cref="System.UnauthorizedAccessException">
/// 3 bad attempts were made to unlock the secret key.
/// </exception>
public MimeEntity Decrypt(out DigitalSignatureCollection signatures)
{
var protocol = ContentType.Parameters["protocol"];
if (string.IsNullOrEmpty(protocol))
{
throw new FormatException();
}
protocol = protocol.Trim().ToLowerInvariant();
if (Count < 2)
{
throw new FormatException();
}
var version = this[0] as MimePart;
if (version == null)
{
throw new FormatException();
}
var ctype = version.ContentType;
var value = string.Format("{0}/{1}", ctype.MediaType, ctype.MediaSubtype);
if (value.ToLowerInvariant() != protocol)
{
throw new FormatException();
}
var encrypted = this[1] as MimePart;
if (encrypted == null || encrypted.ContentObject == null)
{
throw new FormatException();
}
if (!encrypted.ContentType.Matches("application", "octet-stream"))
{
throw new FormatException();
}
using (var ctx = CryptographyContext.Create(protocol)) {
using (var memory = new MemoryBlockStream()) {
var pgp = ctx as OpenPgpContext;
encrypted.ContentObject.DecodeTo(memory);
memory.Position = 0;
if (pgp != null)
{
return(pgp.Decrypt(memory, out signatures));
}
signatures = null;
return(ctx.Decrypt(memory));
}
}
}
public override Stream Verify(Stream signedData, out DigitalSignatureCollection signatures, CancellationToken cancellationToken = default(CancellationToken))
{
throw new NotImplementedException();
}