Mail.DecryptMessage Method

Decrypts the encrypted email by digital certificate.

[Visual Basic]
Public Sub DecryptMessage( _
    cert As X509Certificate2 _
)

[C#]
public void DecryptMessage(
    X509Certificate2 cert
);

[C++]
public: void DecryptMessage(
    X509Certificate2^ cert
);

[JScript]
public function DecryptMessage( 
    cert : X509Certificate2
);

Parameters

cert

The certificate to decrypt the email, if set null ( Nothing in Visual Basic), this method searches certificate from current user certificate storage automatically.

Example

[Visual Basic, C#, C++] The following example demonstrates how to verify signed email and decrypt encrypted email with EAGetMail POP3 & IMAP4 Component. To get the full samples of EAGetMail, please refer to Samples section.

[VB - Verify and Decrypt Email]
Dim mail As Mail = New Mail("TryIt")
mail.Load("c:\test.eml", False)

If mail.IsEncrypted Then
    Try
            ' this email is encrypted, we decrypt it by user default certificate.
            ' you can also use specified certificate like this
            ' Dim decryptCert As New X509Certificate2("D:\mycert\test.pfx",
            '    "nosecret",
            '    X509KeyStorageFlags.Exportable Or X509KeyStorageFlags.UserKeySet)
            ' mail.DecryptMessage(decryptCert)
        
        mail.DecryptMessage(Nothing)
    Catch ep As Exception
        MessageBox.Show(ep.Message)
    End Try
End If

If mail.IsSigned Then
    Try
        Dim signerCert As X509Certificate2 = mail.VerifyMessageSignature()
        MessageBox.Show("This email contains a valid digital signature.")

        ' You can add the certificate to your certificate storage like this
        ' Dim store As New X509Store("My", StoreLocation.CurrentUser)
        ' store.Open(OpenFlags.ReadWrite)
        ' store.Add(signerCert)
        ' store.Close()
        ' then you can use send the encrypted email back to this sender.

    Catch ep As Exception
        MessageBox.Show(ep.Message)
    End Try
End If


[C# - Verify and Decrypt Email]
Mail mail = new Mail("TryIt");
mail.Load("c:\\test.eml", false);

if (mail.IsEncrypted)
{
    try
    {
        // this email is encrypted, we decrypt it by user default certificate.
        // you can also use specified certificate like this
        /* X509Certificate2 decryptCert = new X509Certificate2("D:\\mycert\\test.pfx",
            "nosecret",
            X509KeyStorageFlags.Exportable | X509KeyStorageFlags.UserKeySet);
            mail.DecryptMessage(decryptCert);
            */
        mail.DecryptMessage(null);
    }
    catch (Exception ep)
    {
        MessageBox.Show(ep.Message);
    }
}

if (mail.IsSigned)
{
    try
    {
        // This email is digital signed.
        X509Certificate2 signerCert = mail.VerifyMessageSignature();
        MessageBox.Show("This email contains a valid digital signature.");

        // You can add the certificate to your certificate storage like this
        /*
        X509Store store = new X509Store("My", StoreLocation.CurrentUser);
        store.Open(OpenFlags.ReadWrite);
        store.Add(signerCert);
        store.Close();
        */
        // then you can use send the encrypted email back to this sender.
    }
    catch (Exception ep)
    {
        MessageBox.Show(ep.Message);
    }
}

Remarks

See Also

Mail.IsSigned Property
Mail.VerifySignature Method
Mail.IsEncrypted Property

Online Tutorials

Verify Digital Signature and Decrypt Email in C# - Tutorial
Verify Digital Signature and Decrypt Email in VB.NET - Tutorial
Verify Digital Signature and Decrypt Email in C++/CLI - Tutorial