> Hi Jason,
>
> Thanks for your post!
>
> Based on my knowledge, signing a message means sending a message in clear
> text followed by a message authentication code(MAC), which is a one-way
> hash of the message, and then encrypt the hash value with certain session
> key.
>
> In .Net2.0, Microsoft has added the support for MAC in
> System.Security.Cryptography namespace with HMACSHA256 and ProtectedData
> classes. Please refer to the following 2 articles:
> "Security Enhancements in the .NET Framework 2.0"
> http://msdn.microsoft.com/msdnmag/issues/06/00/SecurityBriefs/default.aspx
> "Security Practices: .NET Framework 2.0 Security Practices at a Glance"
> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpag2/html
> /PAGPractices0002.asp
>
> If I misunderstand you, please feel free to tell me. Thanks
>
> At last, for .Net security issue, there is a dedicated newsgroup
> microsoft.public.dotnet.security.
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Community Support
> ==================================================
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
> ==================================================
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>

> Hi Jason,
>
> Thanks for your feedback!
>
> I am not sure I understand your concern very well. I did not see much magic
> or obstacle of using these 2 classes, the programming model for generating
> MAC is just following  the MSDN of these 2 classes.
>
> Below is the sample code I found for generating HMAC code, hope it meet
> your need(C# and VB.net versions):
> "Generate H Mac Code"
> http://channel9.msdn.com/wiki/default.aspx/SecurityWiki.GenerateHMacCode
> "Generate H Mac Code2"
> http://channel9.msdn.com/wiki/default.aspx/SecurityWiki.GenerateHMacCode2
>
> If I misunderstood your key concern, please feel free to tell me, I will
> work with you. Thanks
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Community Support
> ==================================================
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
> ==================================================
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>

"Eugene Mayevski" wrote:

> Hello!
> You wrote  on Mon, 15 May 2006 21:42:01 -0700:
>
>  J> My Approach with the 2.0 framework is to create the message using the
>  J> Alternateviews and linkresource classes, embedding images etc. Then
>  J> extracting a stream object, use the SignedCMS class to sign the bytes of
>  J> the message using an x509Certificate2 and re-populate the mailMessage
>  J> class with the signed text..I see no need to use the classes that you
>  J> are referencing... or am I missing something??
>
> What you need is S/MIME, while Jeffrey is talking about pure hash
> calculation.
> Since SMIME support is not directly available in .NET Framework (with
> SignedCMS you will have to do certain extra work), you can find it
> time-saving to use a third-party library.
> For S/MIME and PGP/MIME you can take a look at our MIMEBlackbox (
> http://www.eldos.com/sbb/net-mime.php ) which does what you need quickly and
> efficiently.
>
> With best regards,
> Eugene Mayevski
>
>

> Hi Jason,
>
> Thanks for your feedback!
>
> I am not familiar with the email format Outlook needed to verify the email
> content. I am just showing how to generate MAC of a message in .Net2.0.
>
> I do not understand why you want to send a project to me. We did not
> provide project code review for newsgroup.
>
> Can you be clear on what encryption you want to get? Didn't you want to
> calculate the MAC of the email content?
>
> Thanks
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Community Support
> ==================================================
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
> ==================================================
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>

> Hi Jason,
>
> Thanks for your feedback!
>
> Please see inline:
>
> >On my last thread with you (unrelated to this) I was asked to provide a
> code
> >example of my problem. Well, because I had already got half this app
> together
> >when I wrote the original signing test I thought you may understand more
> of
> >what I am trying to do if you saw the code. No need to send it if that is
> not
> >going to help.
> Sorry, but can you be specific about what issue you are referring to? It
> seems that I did not ask you for a project in this thread. Do you mean the
> original DHML editor control post? If so, I suggest you start a new thread,
> and I will continue to work with you on that issue. Sorry for
> misunderstanding you.
>
> >As for encryption, I am NOT looking to encrypt. All I am trying to do is
> >Digitally sign an email with a Digital signature. My test app has this
> >completely working with CAPICOM and CDO I'm just missing some steps (I
> think)
> >when doing this with the 2.0 framework..
> I am not sure why my suggestion did not provide what you want. Based on my
> experience, digital sign means give the message(email content in our
> scenario) a one-way hashing, then encrypt the resulting hashed value with
> certain session key. The final result is called MAC, which is sent with the
> message content. So I provide the class of doing hashing in .Net and the
> class of doing encryption in .Net. Is there any concept misunderstanding in
> my suggestion? Please feel free to point out and tell me what signing
> process you want to get.
>
> Thanks
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Community Support
> ==================================================
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
> ==================================================
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>

> Hi Jason,
>
> Based on my further research, does your "signing an email" mean forming a
> S/MIME Signature in .Net? If so, you may give the below sample code a try:
> "S/MIME VB.NET Examples"
> http://www.example-code.com/vbdotnet/smime.asp
>
> The above sample code requests Chilkat .NET components to do the actual
> work, you can download it from the link below:
> http://www.example-code.com/vbdotnet/step1.asp
>
> If you still have any concern, please feel free to feedback. Thanks!
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Community Support
> ==================================================
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
> ==================================================
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>

> Hi Jason,
>
> Thanks for your feedback!
>
> Yes, since I am not familiar with the Outlook S/MIME signature, I am
> currently doing consulting and coworking with the Outlook experts.
>
> Based on the Reflector decompilation result, the 3rd party Chilkat .NET
> component internally implements all the work with unmanaged code. I am not
> sure if there is any build-in support for S/MIME signature in .Net.
>
> I will try to get more confirmation and information regarding this and
> reply to you ASAP. Thanks for your patient!
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Community Support
> ==================================================
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
> ==================================================
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>

> Hi Jason,
>
> Thanks for your feedback!
>
> If I do not misunderstand you, I think you have managed to use managed code
> to sign the email, the current problem is how to place it in the correct
> email format that Outlook can recognize.
>
> Can you show me some details regarding how you use managed code to do the
> S/MIME digital signing? Based on the consult feedback, there is no build-in
> support for this in .Net:
>
> Your choices are ¨C
> 1. Use a third party component, there are plenty out there, I¡¯ve not
> evaluated any of them so I can¡¯t recommend one.
> 2. You can use COM Interop with CAPICOM to produce digitally
> signed/encrypted e-mails from .NET
>
> Regarding the latter option, you have to write an S/MIME class that
> implements the S/MIME and MIME RFCs. So it's the harder option, but means
> you're free of third party dependencies and licensing, all you need is
> CAPICOM.
>
> Do you think the option2 is suitable for you? Please feel free to tell me,
> thanks!
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Community Support
> ==================================================
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
> ==================================================
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>

> Hi Jason,
>
> Thanks for your patient.
>
> I have received your demo project. However, I still can not get the
> confirmation if there is a build-in support for this in .Net2.0. I am
> current contacting other support team regarding your issue. Thanks for your
> understanding.
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Community Support
> ==================================================
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
> ==================================================
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>

> Hi Jason,
>
> Sorry for letting you wait for so long.
>
> With a lot of discussion and researching with our another support team
> engineer, we are unfortunately to find that  the scenario for supporting
> S/MIME messages was not designed into System.Net.Mail in .Net2.0.
>
> Currently, we have written a sample code snippet with CDO in .Net managed
> code snippet below, for your information:
> =================================Code
> snnipet====================================
> CDO.Message msg2 = new CDO.MessageClass();
> msg2.From = "winson.c.c***@intel.com";
> msg2.To = "winson.c.c***@intel.com";
> msg2.Subject = "Secure Mail Test";
> ================= 1==================
> ADODB.Stream stream2 = msg2.BodyPart.GetEncodedContentStream();
> stream2.Type = ADODB.StreamTypeEnum.adTypeBinary;
> byte[] message = System.Text.UTF8Encoding.UTF8.GetBytes("Can you read
> this?");
> stream2.Write(message);
> stream2.Flush();
> stream2.Close();
> =================2======================
> CDO.Message msg = new CDO.MessageClass();
> msg.From = "winson.c.c***@intel.com";
> msg.To = "winson.c.c***@intel.com";
> msg.Subject = "Secure Mail Test";
> msg.Configuration = new CDO.ConfigurationClass();
> msg.Configuration.Fields[@"http://schemas.microsoft.com/cdo/configuration/se
> ndusing"].Value = 2;
> msg.Configuration.Fields[@"http://schemas.microsoft.com/cdo/configuration/sm
> tpserver"].Value = "myserver";
> msg.Configuration.Fields.Update();
> ====================3================================
> msg.BodyPart.ContentMediaType = "application/pkcs7-mime; name=smime.p7m;
> smime-type=enveloped-data;";
> msg.BodyPart.ContentTransferEncoding = "base64";
> msg.BodyPart.Fields.Append("urn:schemas:mailheader:content-disposition",
> DataTypeEnum.adVarChar, 255, FieldAttributeEnum.adFldUpdatable,
> "attachment; filename=smime.p7m");
> msg.BodyPart.Fields.Update();
> =======================4====================================
> string strContent = msg2.GetStream().ReadText(msg2.GetStream().Size);
> byte[] pbBytes = System.Text.UTF8Encoding.UTF8.GetBytes(strContent);
> GCHandle GCBytes = GCHandle.Alloc(pbBytes, GCHandleType.Pinned);
> IntPtr ptrBytes = GCBytes.AddrOfPinnedObject();           
> envelop.Content = ptrBytes;
> ============================================================
> // encrypt data
> ADODB.Stream stream = msg.BodyPart.GetEncodedContentStream();
> stream.Type = StreamTypeEnum.adTypeText;
> stream.WriteText(envelop.Encrypt(CAPICOM_ENCODING_TYPE.CAPICOM_ENCODE_BASE64
> ), StreamWriteEnum.stWriteLine);
> stream.Flush();
> stream.Close();
> 
> GCBytes.Free();
> 
> // send message
> msg.Send();
> ============================================================================
> ===
> Do let me know how it works for you.
>
> Thanks!
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Community Support
> ==================================================
> When responding to posts, please "Reply to Group" via your newsreader so
> that others may learn and benefit from your issue.
> ==================================================
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>