Sample code for 30+ languages & platforms
Visual Basic 6.0

Socket TLS Mutual Authentication (Client-Side Certificate)

See more Socket/SSL/TLS Examples

This example demonstrates how to provide a client-side certificate, also known as "two-way authentication" or "mutual authentication" for servers that require a client certificate.

Chilkat Visual Basic 6.0 Downloads

Visual Basic 6.0
Dim success As Long
success = 0

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim sock As New ChilkatSocket

' Set the certificate to be used for mutual TLS authentication
' (i.e. sets the client-side certificate for two-way TLS authentication)
success = sock.SetSslClientCertPfx("/home/bob/pfxFiles/myClientSideCertWithPrivateKey.pfx","pfxPassword")
If (success <> 1) Then
    Debug.Print sock.LastErrorText
    Exit Sub
End If

' Note: The certificate used for the client-side of TLS mutual authentication
' must have the associated private key available. (.pfx/.p12 files typically store both
' the certificate and associated private key.)

' Establish the connection using the socket object (with client certificate authentication).
Dim bTls As Long
bTls = 1
Dim port As Long
port = 443
Dim maxWaitMs As Long
maxWaitMs = 5000
success = sock.Connect("www.example.com",port,bTls,maxWaitMs)
If (success <> 1) Then
    Debug.Print "Connect Failure Error Code: " & sock.ConnectFailReason
    Debug.Print sock.LastErrorText
    Exit Sub
End If

' At this point, the Socket object is connected and authenticated using the client-side cert

' ...
' ..