Encrypt Email with Certificate Natively in .Net

29 Nov 2006 5:34 PM

josh

I wrote the following code using the ASPEncrypt .Net Component:

        Dim objMail As IMailSender = New MailSender
        Dim strEmailAddress As String

        objMail.Username = "xxx"
        objMail.Password = "xxx"

        objMail.Host = "xxx"
        objMail.Subject = subject
        objMail.From = replyTo
        objMail.FromName = replyTo
        For Each strEmailAddress In recipientsCleanList
            objMail.AddAddress(strEmailAddress, Nothing)
        Next
        objMail.IsHTML = 1
        objMail.Body = strEmail.ToString

        Dim objCM As ICryptoManager = New CryptoManager
        Dim objContext As ICryptoContext = objCM.OpenContext("", 1,
Nothing)
        Dim strPath As String =
HttpContext.Current.Server.MapPath("secureemail.cer")
        Dim objRecipientCert As ICryptoCert =
objCM.ImportCertFromFile(strPath)
        Dim objMsg As ICryptoMessage = objContext.CreateMessage(1)
        objMsg.AddRecipientCert(objRecipientCert)
        objMail.SendEncrypted(objMsg)

Unfortunately I am using a shared hosting environment whic is set on
"Medium Trust" which means I can't run the code. Can anyone give me an
example of how to do the same thing natively in .Net.

Thanks,

Josh

30 Nov 2006 6:26 AM

VIOT Yves

Hi,
I don't work on ASP but it seems to be near VB.NET (lol). You can't
directly do the Encryption of Mail message (following S/MIME RFCs), in
..NET Framework 2.0. The reason is that the SmtpClient.Send method
doesn't allow MIME Headers overwriting for the Content-Type that should
be "application/pkcs7-mime; smime-type=signed-data; name="smime.p7m" by
his own one (content-type: text/plain; charset=us-ascii). I had
discussion with Fabrizio on this forum and privately, and a solution
could be to implement an SMTP client on your own ;-( which means a lot
of work (SMTP over SSL, SMTP authentication...). There are also
informations on MS Connect website (VB and .NET section searching S/MIME
headers or SMTPClient). Another way is to use CAPICOM.DLL and CDOMessage
object but it is not 100% .NET Framework.
I hope i have helped you
Sorry my poor english
Bye

j***@youinspire.me.uk a écrit :
Show quoteHide quote

> I wrote the following code using the ASPEncrypt .Net Component:
>
>         Dim objMail As IMailSender = New MailSender
>         Dim strEmailAddress As String
>
>         objMail.Username = "xxx"
>         objMail.Password = "xxx"
>
>         objMail.Host = "xxx"
>         objMail.Subject = subject
>         objMail.From = replyTo
>         objMail.FromName = replyTo
>         For Each strEmailAddress In recipientsCleanList
>             objMail.AddAddress(strEmailAddress, Nothing)
>         Next
>         objMail.IsHTML = 1
>         objMail.Body = strEmail.ToString
>
>         Dim objCM As ICryptoManager = New CryptoManager
>         Dim objContext As ICryptoContext = objCM.OpenContext("", 1,
> Nothing)
>         Dim strPath As String =
> HttpContext.Current.Server.MapPath("secureemail.cer")
>         Dim objRecipientCert As ICryptoCert =
> objCM.ImportCertFromFile(strPath)
>         Dim objMsg As ICryptoMessage = objContext.CreateMessage(1)
>         objMsg.AddRecipientCert(objRecipientCert)
>         objMail.SendEncrypted(objMsg)
>
> Unfortunately I am using a shared hosting environment whic is set on
> "Medium Trust" which means I can't run the code. Can anyone give me an
> example of how to do the same thing natively in .Net.
>
> Thanks,
>
> Josh
>