/// <summary>
/// Add an attachment to this e-mail.
/// </summary>
/// <param name="EMailBodypart">An attachment.</param>
public T AddAttachment <T>(EMailBodypart EMailBodypart)
where T : AbstractEMailBuilder
{
_Attachments.Add(EMailBodypart);
return((T)this);
}
/// <summary>
/// Parse an e-mail from the given enumeration of strings.
/// </summary>
/// <param name="MailText">An enumeration of strings.</param>
private EMail(IEnumerable <String> MailText)
: this(MailText.TakeWhile(line => line.IsNotNullOrEmpty()).
AggregateIndentedLines().
ToKeyValuePairs(':'))
{
Body = new EMailBodypart(MailText);
}
/// <summary>
/// Create a new e-mail based on the given e-mail builder.
/// </summary>
/// <param name="MailBuilder">An e-mail builder.</param>
public EMail(AbstractEMailBuilder MailBuilder)
: this(MailBuilder.
EncodeBodyparts().
// Copy only everything which is not related to the e-mail body!
MailHeaders.Where(header => !header.Key.ToLower().StartsWith("content")).
Concat(MailBuilder.Body.MailHeaders))
{
//ToDo: Do a real deep-copy here!
Body = MailBuilder.Body;
//ToDo: Work-aroung for PGP/GPG!
this.From = MailBuilder.From;
this.To = MailBuilder.To;
this.Cc = MailBuilder.Cc;
}
/// <summary>
/// Encode this and all nested e-mail body parts.
/// </summary>
internal AbstractEMailBuilder EncodeBodyparts()
{
var SignTheMail = false;
var EncryptTheMail = false;
EMailBodypart BodypartToBeSecured = null;
#region Add attachments, if available...
if (_Attachments == null ||
_Attachments.Count == 0)
{
BodypartToBeSecured = _EncodeBodyparts();
}
else
{
BodypartToBeSecured = new EMailBodypart(ContentTypeBuilder: AEMail => new MailContentType(AEMail, MailContentTypes.multipart_mixed)
{
CharSet = "utf-8"
}.GenerateMIMEBoundary(),
ContentTransferEncoding: "8bit",
Content: new String[] { "This is a multi-part message in MIME format." },
NestedBodyparts: new EMailBodypart[] { _EncodeBodyparts() }.
Concat(_Attachments));
}
#endregion
#region Check security settings
switch (SecurityLevel)
{
case EMailSecurity.autosign:
if (From.SecretKeyRing != null &&
From.SecretKeyRing.Any() &&
Passphrase.IsNotNullOrEmpty())
{
SignTheMail = true;
}
break;
case EMailSecurity.sign:
if (From.SecretKeyRing == null ||
!From.SecretKeyRing.Any() ||
Passphrase.IsNullOrEmpty())
{
throw new ApplicationException("Can not sign the e-mail!");
}
SignTheMail = true;
break;
case EMailSecurity.auto:
if (From.SecretKeyRing != null &&
From.SecretKeyRing.Any() &&
Passphrase.IsNotNullOrEmpty())
{
SignTheMail = true;
}
if (SignTheMail &&
(!To.Any() | To.Any(v => v.PublicKeyRing != null && v.PublicKeyRing.Any())) &&
(!Cc.Any() | Cc.Any(v => v.PublicKeyRing != null && v.PublicKeyRing.Any())))
{
EncryptTheMail = true;
}
break;
case EMailSecurity.encrypt:
if (From.SecretKeyRing == null ||
!From.SecretKeyRing.Any() ||
Passphrase.IsNullOrEmpty() ||
To.Any(v => v.PublicKeyRing == null || !v.PublicKeyRing.Any()) ||
Cc.Any(v => v.PublicKeyRing == null || !v.PublicKeyRing.Any()))
{
throw new ApplicationException("Can not sign and encrypt the e-mail!");
}
EncryptTheMail = true;
break;
}
#endregion
#region Sign the e-mail
if (SignTheMail & !EncryptTheMail)
{
var DataToBeSigned = BodypartToBeSecured.
// Include headers of this MIME body
// https://tools.ietf.org/html/rfc1847 Security Multiparts for MIME:
ToText().
// Any trailing whitespace MUST then be removed from the signed material
Select(line => line.TrimEnd()).
// Canonical text format with <CR><LF> line endings
// https://tools.ietf.org/html/rfc3156 5. OpenPGP signed data
Aggregate((a, b) => a + "\r\n" + b)
//ToDo: Apply Content-Transfer-Encoding
;
// MIME Security with OpenPGP (rfc3156, https://tools.ietf.org/html/rfc3156)
// OpenPGP Message Format (rfc4880, https://tools.ietf.org/html/rfc4880)
_Body = new EMailBodypart(ContentTypeBuilder: AMail => new MailContentType(AMail, MailContentTypes.multipart_signed)
{
MicAlg = "pgp-sha512",
Protocol = "application/pgp-signature",
CharSet = "utf-8",
},
ContentTransferEncoding: "8bit",
NestedBodyparts: new EMailBodypart[] {
BodypartToBeSecured,
new EMailBodypart(ContentTypeBuilder: AMail => new MailContentType(AMail, MailContentTypes.application_pgp__signature)
{
CharSet = "utf-8"
},
// ContentTransferEncoding: "8bit",
ContentDescription: "OpenPGP digital signature",
ContentDisposition: ContentDispositions.attachment.ToString() + "; filename=\"signature.asc\"",
Content: new String[] {
OpenPGP.CreateSignature(new MemoryStream(DataToBeSigned.ToUTF8Bytes()),
From.SecretKeyRing.First(),
Passphrase,
HashAlgorithm: HashAlgorithm).
WriteTo(new MemoryStream(), CloseOutputStream: false).
ToUTF8String()
})
}
);
}
#endregion
#region Encrypt the e-mail
else if (SignTheMail & EncryptTheMail)
{
var Plaintext = BodypartToBeSecured.ToText().Aggregate((a, b) => a + "\r\n" + b).ToUTF8Bytes();
var Ciphertext = new MemoryStream();
OpenPGP.EncryptSignAndZip(InputStream: new MemoryStream(Plaintext),
Length: (UInt64)Plaintext.Length,
SecretKey: From.SecretKeyRing.First(),
Passphrase: Passphrase,
PublicKey: To.First().PublicKeyRing.First(),
OutputStream: Ciphertext,
SymmetricKeyAlgorithm: SymmetricKeyAlgorithm,
HashAlgorithm: HashAlgorithm,
CompressionAlgorithm: CompressionAlgorithm,
ArmoredOutput: true,
Filename: "encrypted.asc",
LastModificationTime: DateTime.UtcNow);
// MIME Security with OpenPGP (rfc3156, https://tools.ietf.org/html/rfc3156)
// OpenPGP Message Format (rfc4880, https://tools.ietf.org/html/rfc4880)
_Body = new EMailBodypart(ContentTypeBuilder: AMail => new MailContentType(AMail, MailContentTypes.multipart_encrypted)
{
Protocol = "application/pgp-encrypted",
CharSet = "utf-8",
},
ContentTransferEncoding: "8bit",
NestedBodyparts: new EMailBodypart[] {
new EMailBodypart(ContentTypeBuilder: AMail => new MailContentType(AMail, MailContentTypes.application_pgp__encrypted)
{
CharSet = "utf-8"
},
ContentDescription: "PGP/MIME version identification",
ContentDisposition: ContentDispositions.attachment.ToString() + "; filename=\"signature.asc\"",
Content: new String[] { "Version: 1" }),
new EMailBodypart(ContentTypeBuilder: AMail => new MailContentType(AMail, MailContentTypes.application_octet__stream)
{
CharSet = "utf-8"
},
ContentDescription: "OpenPGP encrypted message",
ContentDisposition: ContentDispositions.inline.ToString() + "; filename=\"encrypted.asc\"",
Content: new String[] { Ciphertext.ToArray().ToUTF8String() }),
}
);
}
#endregion
else
{
this._Body = BodypartToBeSecured;
}
return(this);
}
/// <summary>
/// Parse the e-mail from the given text lines.
/// </summary>
/// <param name="MailText">The E-Mail as an enumeration of strings.</param>
public AbstractEMailBuilder(IEnumerable <String> MailText)
: base(MailText)
{
this._Body = new EMailBodypart(MailText);
}
/// <summary>
/// Parse the e-mail from the given e-mail.
/// </summary>
/// <param name="EMail">An e-mail.</param>
public AbstractEMailBuilder(EMail EMail)
: base(EMail)
{
this._Body = new EMailBodypart(EMail.ToText);
}
/// <summary>
/// Create a new e-mail based on the given e-mail builder.
/// </summary>
/// <param name="MailBuilder">An e-mail builder.</param>
public EMail(AbstractEMailBuilder MailBuilder)
: this(MailBuilder.
EncodeBodyparts().
// Copy only everything which is not related to the e-mail body!
MailHeaders.Where(header => !header.Key.ToLower().StartsWith("content")).
Concat(MailBuilder.Body.MailHeaders))
{
//ToDo: Do a real deep-copy here!
Body = MailBuilder.Body;
//ToDo: Work-aroung for PGP/GPG!
this.From = MailBuilder.From;
this.To = MailBuilder.To;
this.Cc = MailBuilder.Cc;
}
/// <summary>
/// Parse an e-mail from the given enumeration of strings.
/// </summary>
/// <param name="MailText">An enumeration of strings.</param>
private EMail(IEnumerable<String> MailText)
: this(MailText.TakeWhile(line => line.IsNotNullOrEmpty()).
AggregateIndentedLines().
ToKeyValuePairs(':'))
{
Body = new EMailBodypart(MailText);
}