Visual FoxPro

POP3 Auto-Refresh Office365 Access Token

See more Office365 Examples

Demonstrates how to automatically recover from an expired OAuth2 access token when OAuth2 authentication fails in the POP3 protocol. If the server responds with "-ERR Authentication failure: unknown user name or bad password.", then we refresh the access token and retry. Visual FoxPro

LOCAL lnSuccess
LOCAL loMailman
LOCAL loJsonToken
LOCAL loOauth2
LOCAL loSbJson
LOCAL lnNumEmails

lnSuccess = 0

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

loMailman = CreateObject('Chilkat.MailMan')

loMailman.MailHost = "outlook.office365.com"
loMailman.MailPort = 995
loMailman.PopSsl = 1

* Use your O365 email address here.
loMailman.PopUsername = "OFFICE365_EMAIL_ADDRESS"

* When using OAuth2 authentication, leave the password empty.
loMailman.PopPassword = ""

* Load our previously obtained OAuth2 access token.
loJsonToken = CreateObject('Chilkat.JsonObject')
lnSuccess = loJsonToken.LoadFile("qa_data/tokens/office365.json")
IF (lnSuccess = 0) THEN
    ? loJsonToken.LastErrorText
    RELEASE loMailman
    RELEASE loJsonToken
    CANCEL
ENDIF

loMailman.OAuth2AccessToken = loJsonToken.StringOf("access_token")

* Make the TLS connection to the outlook.office365.com POP3 server.
lnSuccess = loMailman.Pop3Connect()
IF (lnSuccess <> 1) THEN
    ? loMailman.LastErrorText
    RELEASE loMailman
    RELEASE loJsonToken
    CANCEL
ENDIF

* Authenticate using XOAUTH2
lnSuccess = loMailman.Pop3Authenticate()
IF (lnSuccess <> 1) THEN
    * If we're still connected to the mail server, then it means the server sent a non-success response,
    * Such as:  -ERR Authentication failure: unknown user name or bad password.
    IF (loMailman.IsPop3Connected = 1) THEN

        * Refresh the OAuth2 access token, and if successful, save the new (refreshed) access token and try authenticating again.
        loOauth2 = CreateObject('Chilkat.OAuth2')

        * Use your actual Directory (tenant) ID instead of "112d7ed6-71bf-4eba-a866-738364321bfc"
        loOauth2.TokenEndpoint = "https://login.microsoftonline.com/112d7ed6-71bf-4eba-a866-738364321bfc/oauth2/v2.0/token"

        * Replace these with your Azure App Registration's actual values.
        loOauth2.ClientId = "CLIENT_ID"
        loOauth2.ClientSecret = "CLIENT_SECRET"

        * Get the "refresh_token"
        loOauth2.RefreshToken = loJsonToken.StringOf("refresh_token")

        * Send the HTTP POST to refresh the access token..
        lnSuccess = loOauth2.RefreshAccessToken()
        IF (lnSuccess <> 1) THEN
            ? loOauth2.LastErrorText
            RELEASE loMailman
            RELEASE loJsonToken
            RELEASE loOauth2
            CANCEL
        ENDIF

        ? "New access token: " + loOauth2.AccessToken
        ? "New refresh token: " + loOauth2.RefreshToken

        * Update the JSON with the new tokens.
        loJsonToken.UpdateString("access_token",loOauth2.AccessToken)
        loJsonToken.UpdateString("refresh_token",loOauth2.RefreshToken)

        * Save the new JSON access token response to a file.
        loSbJson = CreateObject('Chilkat.StringBuilder')
        loJsonToken.EmitCompact = 0
        loJsonToken.EmitSb(loSbJson)
        loSbJson.WriteFile("qa_data/tokens/office365.json","utf-8",0)

        ? "New Access Token = " + loOauth2.AccessToken

        * Update the mailman with the new access token.
        loMailman.OAuth2AccessToken = loOauth2.AccessToken

        * Retry the authentication.
        lnSuccess = loMailman.Pop3Authenticate()
        IF (lnSuccess = 0) THEN
            ? loMailman.LastErrorText
            RELEASE loMailman
            RELEASE loJsonToken
            RELEASE loOauth2
            RELEASE loSbJson
            CANCEL
        ENDIF

    ELSE
        ? loMailman.LastErrorText
        RELEASE loMailman
        RELEASE loJsonToken
        RELEASE loOauth2
        RELEASE loSbJson
        CANCEL
    ENDIF

ENDIF

* Find out how many emails are on the server..
lnNumEmails = loMailman.CheckMail()
IF (lnNumEmails < 0) THEN
    ? loMailman.LastErrorText
    RELEASE loMailman
    RELEASE loJsonToken
    RELEASE loOauth2
    RELEASE loSbJson
    CANCEL
ENDIF

* Examine the POP3 session log:
? loMailman.Pop3SessionLog

* The POP3 session log will look something like this:

* **** Connected to outlook.office365.com:995
* < +OK The Microsoft Exchange POP3 service is ready. [QwBIADIAUABSADEANgBDAEEAMAAwADEAMgAuAG4AYQBtAHAAcgBkADEANgAuAHAAcgBvAGQALgBvAHUAdABsAG8AbwBrAC4AYwBvAG0A]
* > AUTH XOAUTH2
* < + 
* > <base64 string in XOAUTH2 format>
* < -ERR Authentication failure: unknown user name or bad password.
* > AUTH XOAUTH2
* < + 
* > <base64 string in XOAUTH2 format>
* < +OK User successfully authenticated.
* > STAT
* < +OK 248 46637086

* End the POP3 session and close the connection to the GMail server.
lnSuccess = loMailman.Pop3EndSession()
IF (lnSuccess <> 1) THEN
    ? loMailman.LastErrorText
    RELEASE loMailman
    RELEASE loJsonToken
    RELEASE loOauth2
    RELEASE loSbJson
    CANCEL
ENDIF

? "Finished."

RELEASE loMailman
RELEASE loJsonToken
RELEASE loOauth2
RELEASE loSbJson