public void ThrowIfInvalid()
{
Recipients.ThrowIfNullOrEmpty(nameof(Recipients));
Subject.ThrowIfNullOrEmpty(nameof(Subject));
ViewPath.ThrowIfNullOrEmpty(nameof(ViewPath));
foreach (string recipient in Recipients)
{
if (!StringHelpers.IsValidEmail(recipient))
{
throw new InvalidOperationException($"Email '{recipient}' is invalid");
}
}
if (Cc.Any())
{
foreach (string cc in Cc)
{
if (!StringHelpers.IsValidEmail(cc))
{
throw new InvalidOperationException($"Email '{cc}' is invalid");
}
}
}
}
public void ThrowIfInvalid()
{
Recipients.ThrowIfNullOrEmpty(nameof(Recipients));
Subject.ThrowIfNullOrEmpty(nameof(Subject));
ViewPath.ThrowIfNullOrEmpty(nameof(ViewPath));
foreach (string recipient in Recipients)
{
if (!StringHelpers.IsValidEmail(recipient))
{
throw new InvalidOperationException($"Email '{recipient}' is invalid");
}
}
if (Cc.Any())
{
foreach (string cc in Cc)
{
if (!StringHelpers.IsValidEmail(cc))
{
throw new InvalidOperationException($"Email '{cc}' is invalid");
}
}
Cc = Cc.Where(x => !Recipients.Contains(x)).ToArray();
}
if (HiddenCc.Any())
{
foreach (string cc in HiddenCc)
{
if (!StringHelpers.IsValidEmail(cc))
{
throw new InvalidOperationException($"Email '{cc}' is invalid");
}
}
HiddenCc = HiddenCc
.Where(x => !Cc.Contains(x))
.Where(x => !Recipients.Contains(x)).ToArray();
}
}
/// <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);
}
public override string ToString()
{
StringBuilder sb = new StringBuilder();
string boundary = Guid.NewGuid().ToString();
var date = DateTime.Now.ToString("ddd, d MMM yyyy H:m:s zz00");
var subject = !Equals(SubjectEncoding, Encoding.ASCII)
? EncodeQuotedPrintableHeader(Subject, SubjectEncoding)
: Subject;
AddHeader(sb, "From", FormatMailAddress(From, HeaderEncoding));
if (To.Any())
{
AddHeader(sb, "To", String.Join(", ", To.Select(t => FormatMailAddress(t, HeaderEncoding))));
}
if (Cc.Any())
{
AddHeader(sb, "Cc", String.Join(", ", Cc.Select(t => FormatMailAddress(t, HeaderEncoding))));
}
AddHeader(sb, "Subject", subject);
AddHeader(sb, "MIME-Version", "1.0");
AddHeader(sb, "Date", date);
AddHeader(sb, "Message-ID", MessageId);
foreach (var additionalHeader in AdditionalHeaders)
{
AddHeader(additionalHeader.Name, additionalHeader.Value);
}
if (Attachments.Any())
{
AddHeader(sb, "Content-Type", "multipart/mixed; boundary=" + boundary);
AddLine(sb, "");
AddLine(sb, "--" + boundary);
}
string boundary2 = Guid.NewGuid().ToString();
AddHeader(sb, "Content-Type", "multipart/alternative; boundary=" + boundary2);
AddLine(sb, "");
AddLine(sb, "--" + boundary2);
AddHeader(sb, "Content-Type", "text/plain; charset=" + BodyEncoding.HeaderName);
AddHeader(sb, "Content-Transfer-Encoding", "quoted-printable");
AddHeader(sb, "Content-Disposition", "inline");
AddLine(sb, "");
AddLine(sb, encodeQuotedPrintable(Text, BodyEncoding));
AddLine(sb, "--" + boundary2);
AddHeader(sb, "Content-Type", "text/html; charset=" + BodyEncoding.HeaderName);
AddHeader(sb, "Content-Transfer-Encoding", "quoted-printable");
AddHeader(sb, "Content-Disposition", "inline");
AddLine(sb, "");
AddLine(sb, encodeQuotedPrintable(Html, BodyEncoding));
AddLine(sb, "--" + boundary2 + "--");
if (Attachments.Any())
{
AddLine(sb, "");
foreach (var attachment in Attachments)
{
AddLine(sb, "--" + boundary);
if (attachment.Encoding != null)
{
AddHeader(sb, "Content-Type", attachment.Type + "; charset=" + attachment.Encoding.HeaderName);
}
else
{
AddHeader(sb, "Content-Type", attachment.Type);
}
AddHeader(sb, "Content-Transfer-Encoding", "base64");
AddHeader(sb, "Content-Disposition", "attachment; filename=" + attachment.Name);
AddLine(sb, "");
AddLine(sb, Convert.ToBase64String(attachment.Data, Base64FormattingOptions.InsertLineBreaks));
}
AddLine(sb, "--" + boundary + "--");
}
return(sb.ToString());
}