Visual Basic 6.0
Visual Basic 6.0
Use a TLS Client Certificate
See more SMTP Examples
Demonstrates the Chilkat MailMan.SetSslClientCert method, which sets the client-side certificate to use for SSL/TLS connections. This is typically not required — most SSL/TLS connections authenticate the server only. This example loads a client certificate from a PFX and uses it when connecting.
Background: In an ordinary TLS handshake only the server presents a certificate, and the client proves who it is later with a password. Mutual TLS adds a second leg: the client also presents a certificate, so it is authenticated cryptographically at the transport layer. Some corporate or high-security mail servers require this. Because the client must prove possession of the key, the certificate needs its private key — hence loading from a PFX.
Chilkat Visual Basic 6.0 Downloads
Dim success As Long
success = 0
' Demonstrates the MailMan.SetSslClientCert method, which sets the client-side certificate
' to use for SSL/TLS connections. This is typically not required -- most SSL/TLS
' connections authenticate the server only.
Dim mailman As New ChilkatMailMan
' Configure the SMTP server connection.
mailman.SmtpHost = "smtp.example.com"
mailman.SmtpPort = 465
mailman.SmtpSsl = 1
mailman.SmtpUsername = "user@example.com"
mailman.SmtpPassword = "myPassword"
' Load the client certificate (with its private key) from a PFX file.
Dim cert As New ChilkatCert
success = cert.LoadPfxFile("qa_data/certs/client.pfx","pfx_password")
If (success = 0) Then
Debug.Print cert.LastErrorText
Exit Sub
End If
' Use this certificate to identify the client during the TLS handshake.
success = mailman.SetSslClientCert(cert)
If (success = 0) Then
Debug.Print mailman.LastErrorText
Exit Sub
End If
success = mailman.VerifySmtpLogin()
If (success = 0) Then
Debug.Print mailman.LastErrorText
Exit Sub
End If
Debug.Print "Connected using a TLS client certificate."
' Note: The path "qa_data/certs/client.pfx" is a relative local filesystem path,
' relative to the current working directory of the running application.