(VB.NET) SFTP Auth Failure Reason (AuthenticatePwPk)

This example demonstrates how to determine the failure reason for the case where both a password and private key are required for authentication. If authentication fails, was it because of an invalid private key, or an invalid password?

Note: This example requires Chilkat v11.0.0 or greater.

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Dim success As Boolean = False

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

' Load a private key to be used for SSH authentication.
Dim key As New Chilkat.SshKey
key.Password = "key_password"

success = key.FromOpenSshPrivateKey(key.LoadText("qa_data/my_private_key_file"))
If (success = False) Then
    Debug.WriteLine(key.LastErrorText)
    Exit Sub
End If


Dim sftp As New Chilkat.SFtp

success = sftp.Connect("sftp.example.com",22)
If (success = False) Then
    Debug.WriteLine(sftp.LastErrorText)
    Exit Sub
End If


' Authenticate using both a password and private key.
success = sftp.AuthenticatePwPk("myLogin","myPassword",key)
If (success = True) Then
    Debug.WriteLine("Authentication is successful!")
    Exit Sub
End If


' If we get here, it means the authentication failed.
' Examine the last JSON data..

Dim json As New Chilkat.JsonObject
sftp.GetLastJsonData(json)

json.EmitCompact = False

' This is the JSON if the key is correct, but the password is incorrect:

' {
'   "public_key_type": "rsa",
'   "partialAuthResult": "publickey success. continue to authenticate with password...",
'   "authResult": "failed",
'   "authFailReason": "Password is incorrect"
' }

' This is the JSON if the key is incorrect.  We won't know if the password is also incorrect until
' the key is made correct so that authentication proceeds to check the password.

' {
'   "public_key_type": "rsa",
'   "authResult": "failed",
'   "authFailReason": "Key is incorrect"
' }

' To get the authResult anbd authFailReason:
Debug.WriteLine("authResult: " & json.StringOf("authResult"))
Debug.WriteLine("authFailReason: " & json.StringOf("authFailReason"))