Digital Signatures

[krazysmile]

Hey everyone.
Im coming from this thread: http://www.thescripts.com/forum/thread117164.html
Cant reply there, so im making a new one, also the last post is very old.

Im trying to sing an email message.
Ive tryed with System.net.mail, and i can do it, but it dont has support for attachments (that i know of).
So i went to CDO.
After checking a lot in the net, come up with that post, and try it.

It does send the mail, and when i open it with Evolution Mail (Linux) the signature is recognized and it says valid signature.
But when i send the mail, and open it with Outlook, it does recognize the signature, but it says the mail has been altered (and it dont)
Also a "funny" thing, the signing date for that mail, in details, is somewhere in 1601...
Do my only gess is that the signature is bad.

if anyone can help, i really apreciate.

Regards

Following is the code im usign:

using System.Collections.Generic;
using System;
using System.IO;
using System.Text;
using System.Net.Mail;
using System.Security.Cryptography.Pkcs;
using System.Security.Cryptography.X509Certificates;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Security.Cryptography;
using System.Runtime.InteropServices;
using System.Diagnostics;
 
 
/*  ADD REFERENCES TO
 *          ADOBD
 *          Interop.CDO
 * 
 */
 
 
namespace EmailTesteCsharp1
{
    class Program
    {
        static void Main(string[] args)
        {
 
            Program x = new Program();
            x.mySendMail("[e-mail]", "[e-mail]", "[e-mail]", "Novo mail", "body do email");
 
        }
 
        private void mySendMail(string to, string from, string cc, string subject,string body)
        {
            CDO.Message oSignedMsg = new CDO.Message();
            oSignedMsg.From = "[e-mail]";
            oSignedMsg.To = to;
            if(cc != null && cc.Trim() != "")
            {
                oSignedMsg.CC = cc;
            }
            oSignedMsg.Subject = subject;
            oSignedMsg.MimeFormatted = true;
            oSignedMsg.BodyPart.ContentMediaType = "multipart/signed;\rprotocol=" +
                                        '\u0022' + "application/x-pkcs7-signature" + '\u0022' + ";\rmicalg=SHA1;";
 
            oSignedMsg.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/sendusing"].Value = 2;
            oSignedMsg.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/smtpserver"].Value = "10.0.0.2";
            oSignedMsg.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/smtpserverport"].Value = 25;
            oSignedMsg.Configuration.Fields.Update();
 
            CDO.IBodyPart oBodyPart = oSignedMsg.BodyPart.AddBodyPart(oSignedMsg.BodyPart.BodyParts.Count + 1);
            oBodyPart.ContentMediaType = "multipart/mixed";
 
            CDO.IBodyPart oBodyPart2 = oBodyPart.AddBodyPart(oBodyPart.BodyParts.Count + 1);
            oBodyPart2.ContentMediaType = "text/plain;charset=\"iso-8859-1\"";
            ADODB.Stream oStream = oBodyPart2.GetDecodedContentStream();
            oStream.WriteText(body, 0);
            oStream.Flush();
            oStream.Close();
 
            CDO.IBodyPart oSigniturePart = oSignedMsg.BodyPart.AddBodyPart(oSignedMsg.BodyPart.BodyParts.Count + 1);
            oSigniturePart.ContentMediaType = "application/x-pkcs7-signature";
            oSigniturePart.ContentTransferEncoding = "base64";
            oSigniturePart.Fields["urn:schemas:mailheader:content-disposition"].Value
                                                = "attachment;\rFileName=" + '\u0022' + "smime.p7s" + '\u0022' + "";
            oSigniturePart.Fields.Update();
 
 
            oStream = oSignedMsg.GetStream();
            string messageToSign = oStream.ReadText(oStream.Size);
            byte[] byteSignature = signMessage1(messageToSign);
 
 
            oStream = oSigniturePart.GetDecodedContentStream();
            oStream.Type = ADODB.StreamTypeEnum.adTypeBinary;
            oStream.Write(byteSignature);
            oStream.Flush();
            oStream.Close();
 
            oSignedMsg.Send();
        }
 
 
        public byte[] signMessage1(string msg)
        {
            X509Certificate2 signerCert = new X509Certificate2("MyPfxFile.pfx", "MyPfxPassword");                       
            byte[] msgBytes = Encoding.Unicode.GetBytes(msg);
 
 
            byte[] encodedSignedCms = SignMsg1(msgBytes, signerCert);
            return encodedSignedCms;
        }
 
        static public byte[] SignMsg1(Byte[] msg, X509Certificate2 signerCert)
        {
            //  Place message in a ContentInfo object.
            //  This is required to build a SignedCms object.
            ContentInfo contentInfo = new ContentInfo(msg);
 
            //  Instantiate SignedCms object with the ContentInfo above.
            //  Has default SubjectIdentifierType IssuerAndSerialNumber.
            //  Has default Detached property value false, so message is
            //  included in the encoded SignedCms.
            SignedCms signedCms = new SignedCms(contentInfo);
 
            //  Formulate a CmsSigner object for the signer.
            CmsSigner cmsSigner = new CmsSigner(signerCert);
 
            //  Sign the CMS/PKCS #7 message.
            //Console.Write("Computing signature with signer subject " + "name {0} ... ", signerCert.SubjectName.Name);
            signedCms.ComputeSignature(cmsSigner);
            //Console.WriteLine("Done.");
 
            //  Encode the CMS/PKCS #7 message.
            return signedCms.Encode();
        }
 
 
 
    }
}