VB.NET

Hotmail Refresh Access Token (also for Live.com, Outlook.com)

See more OAuth2 Examples

An OAuth2 access token is typically valid for 1 hour. Interaction with the Hotmail account owner via a browser is only needed for getting the initial access token. Once you have it, it can be continually refreshed without user interaction for a long time.

See: How Long can an OAuth2 Access Token be Refreshed?

VB.NET

Dim success As Boolean = False

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

' It is assumed we previously obtained an OAuth2 access token.

' Note: Refreshing an access token does not require user-interaction.  
' Only the act of getting the initial access token requires interactive authorization from the Hotmail account owner 
' (i.e. a browser is displayed and the Hotmail account owner authorizes access by the app).

' Once you have the initial access token, it can be refreshed for a long time.
' A typical strategy is to write your application to automatically refresh the access token 
' when authentication fails, and then retry the operation with the new access token.

Dim jsonToken As New Chilkat.JsonObject
success = jsonToken.LoadFile("qa_data/tokens/hotmail.json")
If (success <> True) Then
    Debug.WriteLine("Failed to load office365.json")
    Exit Sub
End If


' The access token JSON looks like this:

' {
'   "token_type": "Bearer",
'   "scope": "https://outlook.office.com/SMTP.Send https://outlook.office.com/IMAP.AccessAsUser.All https://outlook.office.com/POP.AccessAsUser.All",
'   "expires_in": 3600,
'   "ext_expires_in": 3600,
'   "access_token": "EwBoA+ ... 7pOYcWr5pFwQgI=",
'   "refresh_token": "M.C546_BL2.0.U.-CkW ... g5CKSlDBQ$$",
'   "id_token": "eyJ0e ... 2iiu5iqBK9n7s3A"
' }

Dim oauth2 As New Chilkat.OAuth2

' See Microsoft OAuth2 Authorization Endpoint
oauth2.TokenEndpoint = "https://login.microsoftonline.com/common/oauth2/v2.0/token"

' Replace this with your actual App Registration's Application (client) ID.
oauth2.ClientId = "CLIENT_ID"

' Get the "refresh_token"
oauth2.RefreshToken = jsonToken.StringOf("refresh_token")

' Send the HTTP POST to refresh the access token..
success = oauth2.RefreshAccessToken()
If (success <> True) Then
    Debug.WriteLine(oauth2.LastErrorText)
    Exit Sub
End If

Debug.WriteLine(oauth2.LastErrorText)

Debug.WriteLine("New access token: " & oauth2.AccessToken)
Debug.WriteLine("New refresh token: " & oauth2.RefreshToken)

' Update the JSON with the new tokens.
jsonToken.UpdateString("access_token",oauth2.AccessToken)
jsonToken.UpdateString("refresh_token",oauth2.RefreshToken)

' Save the new JSON access token response to a file.
Dim sbJson As New Chilkat.StringBuilder
jsonToken.EmitCompact = False
jsonToken.EmitSb(sbJson)
sbJson.WriteFile("qa_data/tokens/hotmail.json","utf-8",False)

Debug.WriteLine("OAuth2 authorization granted!")
Debug.WriteLine("New Access Token = " & oauth2.AccessToken)