(DataFlex) Office365 OAuth2 Client Credentials Flow for SMTP, IMAP, POP

See more Office365 Examples

Demonstrates how to get an OAuth2 access token using the Client Credentials flow for use with Office 365 in the SMTP, IMAP, and POP3 protocols.

This is a way of getting an OAuth2 access token for the O365 account you own, WITHOUT needing to grant access interactively via a browser.

Note: OAuth2 access tokens acquired using client credentials are not refreshed. This is because no interactive browser authentication was initially required. You can simply fetch another access token using client credentials using this sample code. Access tokens aquired using client credentials typically have a lifetime of 1 hour.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoHttp
    Variant vReq
    Handle hoReq
    Variant vResp
    Handle hoResp
    Integer iStatusCode
    Handle hoFac
    Boolean iSuccess
    String sTemp1
    Boolean bTemp1

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

    // Get an OAuth2 access token by sending a POST like this:

    // 	POST {tenant}/oauth2/v2.0/token
    // 	Host: login.microsoftonline.com
    // 	Content-Type: application/x-www-form-urlencoded
    // 
    // 	client_id=6731de76-14a6-49ae-97bc-6eba6914391e
    // 	&client_secret=*****************
    // 	&scope=https%3A%2F%2Foutlook.office365.com%2F.default
    // 	&grant_type=client_credentials

    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End

    Get Create (RefClass(cComChilkatHttpRequest)) To hoReq
    If (Not(IsComObjectCreated(hoReq))) Begin
        Send CreateComObject of hoReq
    End

    // ----------------------------------------------------------------------------------------
    // Important:
    // Your Azure Entra ID app must be explicitly setup to allow for the OAuth2 client credentials flow.
    // Please follow the detailed guide for how to do it here:
    // Office365 App Setup for SMTP, POP, IMAP OAuth2 Client Credentials
    // 
    // Note: Your registered App must have the following permissions.
    // For IMAP: IMAP.AccessAsApp
    // For POP3: POP.AccessAsApp
    // For SMTP: SMTP.SendAsApp
    // ----------------------------------------------------------------------------------------

    // Use the application ID for the client_id.
    // (In Azure App Registrations, use the Application (client) ID)
    Send ComAddParam To hoReq "client_id" "CLIENT_ID"
    Send ComAddParam To hoReq "client_secret" "CLIENT_SECRET"
    Send ComAddParam To hoReq "scope" "https://outlook.office365.com/.default"
    Send ComAddParam To hoReq "grant_type" "client_credentials"

    // Replace "{tenant}" with your tenant ID, such as "112d7ed6-71bf-4eba-a866-738364321bfc".
    Get pvComObject of hoReq to vReq
    Get ComPostUrlEncoded Of hoHttp "https://login.microsoftonline.com/{tenant}/oauth2/v2.0/token" vReq To vResp
    If (IsComObject(vResp)) Begin
        Get Create (RefClass(cComChilkatHttpResponse)) To hoResp
        Set pvComObject Of hoResp To vResp
    End
    Get ComLastMethodSuccess Of hoHttp To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComStatusCode Of hoResp To iStatusCode
    Showln "response status code: " iStatusCode
    Showln "response body:"
    Get ComBodyStr Of hoResp To sTemp1
    Showln sTemp1

    // The successful JSON response looks like this:

    // {
    //   "token_type": "Bearer",
    //   "expires_in": 3599,
    //   "ext_expires_in": 3599,
    //   "access_token": "eyJ0eX...ZKaeSVSg"
    // }

    // Save the JSON to a file for future requests.
    // The Office365 access token acquired by client credentials is typically valid for ..
    If (iStatusCode = 200) Begin
        Get Create (RefClass(cComCkFileAccess)) To hoFac
        If (Not(IsComObjectCreated(hoFac))) Begin
            Send CreateComObject of hoFac
        End
        Get ComBodyStr Of hoResp To sTemp1
        Get ComWriteEntireTextFile Of hoFac "qa_data/tokens/office365.json" sTemp1 "utf-8" False To iSuccess
    End

    Send Destroy of hoResp


End_Procedure