(Classic ASP) Refresh GMail SMTP OAuth2 Access Token

See more OAuth2 Examples

Demonstrates how to refresh an access token for sending email via GMail (SMTP).

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

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

' See Get GMail SMTP Access Token 
' for sample code showing how to obtain a GMail SMTP access token for desktop apps.

' It is assumed we previously obtained an OAuth2 access token for GMail (one with a scope for sending email).

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.JsonObject")
set jsonToken = Server.CreateObject("Chilkat.JsonObject")
success = jsonToken.LoadFile("qa_data/tokens/_gmailSmtp.json")
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( "Failed to load _gmailSmtp.json") & "</pre>"
    Response.End
End If

' The access token JSON looks something like this:

' 	{ 
' 	 "access_token": "abac.Ci-ZabcdF37-NUrmSzxbHxTsMbtlN-uPfabcdAQN_2ekzj0s5ofCzRabcdTDMGaa2Q",
' 	 "token_type": "Bearer",
' 	 "expires_in": 3600,
' 	 "refresh_token": "1/lEe5abcdNJ77eOSDBabcdkQGVmDalkwabcdR2Hatbo"
' 	}
' 

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.OAuth2")
set oauth2 = Server.CreateObject("Chilkat.OAuth2")

oauth2.TokenEndpoint = "https://www.googleapis.com/oauth2/v4/token"

' Replace these with actual values.
oauth2.ClientId = "GOOGLE-CLIENT-ID"
oauth2.ClientSecret = "GOOGLE-CLIENT-SECRET"

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

' Send the HTTP POST to refresh the access token..
success = oauth2.RefreshAccessToken()
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( oauth2.LastErrorText) & "</pre>"
    Response.End
End If

' The response contains a new access token, but we must keep
' our existing refresh token for when we need to refresh again in the future.
success = jsonToken.UpdateString("access_token",oauth2.AccessToken)

' Save the new JSON access token response to a file.
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.StringBuilder")
set sbJson = Server.CreateObject("Chilkat.StringBuilder")
jsonToken.EmitCompact = 0
success = jsonToken.EmitSb(sbJson)
success = sbJson.WriteFile("qa_data/tokens/_gmailSmtp.json","utf-8",0)

Response.Write "<pre>" & Server.HTMLEncode( "OAuth2 authorization granted!") & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( "New Access Token = " & oauth2.AccessToken) & "</pre>"

%>
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