public void SendEncryptedEmail(EncryptedEmail encryptedEmail)
{
Logger.LogTrace($"Sending {encryptedEmail.ToString()}");
if (EmailSenderConfiguration.IsDisabled)
{
// used in unit-tests to prevent mass email sending...
return;
}
IList <MailMessage> mailMessages;
if (EmailSenderConfiguration.InSimulationMode)
{
Logger.LogWarning($"InSimulation Mode -> Changing Recipients: {EmailSenderConfiguration.AdministratorEmailAddresses.ToSeparatedString( a => a )}");
var simulatedEmailBody = "<div style='font-family: Arial, Verdana; font-size: 10px; font-weight: bold'>" +
"This mail would have been sent to:" +
"<br/>" + encryptedEmail.Recipients.ToSeparatedString(t => t.Address) +
"<br /><br /></div>" +
"-- The encrypted mail body is hidden in a simulated, unencrypted mail --";
var simulatedEmail = new Email(from: encryptedEmail.From, to: EmailSenderConfiguration.AdministratorEmailAddresses, cc: null, bcc: null, subject: encryptedEmail.Subject, body: simulatedEmailBody, attachments: encryptedEmail.Attachments != null ? encryptedEmail.Attachments.ToArray() : null);
mailMessages = ConvertEmailToMailMessages(simulatedEmail);
}
else
{
mailMessages = ConvertEncryptedEmailToMailMessages(encryptedEmail);
}
this.SendMailMessages(mailMessages);
}
private IList <MailMessage> ConvertEncryptedEmailToMailMessages(EncryptedEmail encryptedEmail)
{
var mailMessages = new List <MailMessage>();
var body = encryptedEmail.Body.Replace("\r", "").Replace("\n", "<br />");
var sb = new StringBuilder();
if (encryptedEmail.Attachments != null && encryptedEmail.Attachments.Count > 0)
{
sb.Append("MIME-Version: 1.0\r\n");
sb.Append("Content-Type: multipart/mixed; boundary=unique-boundary-1\r\n");
sb.Append("\r\n");
sb.Append("This is a multi-part message in MIME format.\r\n");
sb.Append("--unique-boundary-1\r\n");
sb.Append("Content-Type: text/html; charset=\"utf-8\"\r\n");
sb.Append("Content-Transfer-Encoding: 7Bit\r\n\r\n");
sb.Append(body);
if (!body.EndsWith("\r\n"))
{
sb.Append("\r\n");
}
sb.Append("\r\n\r\n");
foreach (var attachment in encryptedEmail.Attachments)
{
sb.Append("--unique-boundary-1\r\n");
sb.Append("Content-Type: application/octet-stream; file=" + attachment.FileName + "\r\n");
sb.Append("Content-Transfer-Encoding: base64\r\n");
sb.Append("Content-Disposition: attachment; filename=" + attachment.FileName + "\r\n");
sb.Append("\r\n");
byte[] binaryData = attachment.Data;
string base64Value = Convert.ToBase64String(binaryData, 0, binaryData.Length);
int position = 0;
while (position < base64Value.Length)
{
int chunkSize = 100;
if (base64Value.Length - (position + chunkSize) < 0)
{
chunkSize = base64Value.Length - position;
}
sb.Append(base64Value.Substring(position, chunkSize));
sb.Append("\r\n");
position += chunkSize;
}
sb.Append("\r\n");
}
}
else
{
sb.AppendLine("Content-Type: text/html; charset=\"utf-8\"");
sb.AppendLine("Content-Transfer-Encoding: 7bit");
sb.AppendLine();
sb.AppendLine(body);
}
var bodyData = Encoding.UTF8.GetBytes(sb.ToString());
foreach (var recipient in encryptedEmail.Recipients)
{
var envelopedCms = new EnvelopedCms(new ContentInfo(bodyData));
var cmsRecipient = new CmsRecipient(SubjectIdentifierType.IssuerAndSerialNumber, recipient.Certificate);
envelopedCms.Encrypt(cmsRecipient);
var encryptedBytes = envelopedCms.Encode();
var mailMessage = new MailMessage(encryptedEmail.From, recipient.Address)
{
Priority = encryptedEmail.MailPriority,
DeliveryNotificationOptions = encryptedEmail.DeliveryNotificationOptions,
Subject = encryptedEmail.Subject,
IsBodyHtml = true
};
mailMessage.AlternateViews.Add(new AlternateView(new MemoryStream(encryptedBytes), "application/pkcs7-mime; smime-type=signed-data; name=smime.p7m"));
if (!string.IsNullOrEmpty(mailMessage.Subject))
{
while (("=?utf-8?B?" + Convert.ToBase64String(mailMessage.Subject.ToByte(System.Text.Encoding.UTF8)) + "?=").Length > 255)
{
// Bugfix for some mailservers/clients which cannot handle UTF8-encoded and to Base64 converted strings which are longer than 255 characters (including control characters)
mailMessage.Subject = mailMessage.Subject.RemoveLast(10) + "...";
}
}
mailMessages.Add(mailMessage);
}
return(mailMessages);
}
