(SQL Server) HMRC OAuth2 Access Token

Demonstrates how to get an HMRC OAuth2 access token from a desktop (installed) application or script. This example gets an HMRC MTD VAT read/write access token.

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

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This example requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @oauth2 int
    -- Use "Chilkat_9_5_0.OAuth2" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.OAuth2', @oauth2 OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int

    -- This should be the port in the localhost callback URL for your app.
    -- Important: Make sure the callback URI in your HMRC developer app 
    -- is exactly "http://localhost:3017/".  Don't forget the ending "/" char.
    -- The callback URL would look like "http://localhost:3017/" if the port number is 3017.

    -- IMPORTANT: Don't forget to setup your HMRC application to use the Redirect URI "http://localhost:3017/" as shown
    -- here: Configure Redirect URI for HMRC application
    EXEC sp_OASetProperty @oauth2, 'ListenPort', 3017

    EXEC sp_OASetProperty @oauth2, 'AuthorizationEndpoint', 'https://test-api.service.hmrc.gov.uk/oauth/authorize'
    EXEC sp_OASetProperty @oauth2, 'TokenEndpoint', 'https://test-api.service.hmrc.gov.uk/oauth/token'

    -- Replace these with actual values.
    EXEC sp_OASetProperty @oauth2, 'ClientId', 'HMRC-CLIENT-ID'
    EXEC sp_OASetProperty @oauth2, 'ClientSecret', 'HMRC-CLIENT-SECRET'

    -- The scopes are documented in the HMRC reference documentation for each API.
    -- This example gets a read/write access token for the HMRC MTD VAT API.
    EXEC sp_OASetProperty @oauth2, 'Scope', 'read:vat write:vat'

    -- Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
    DECLARE @url nvarchar(4000)
    EXEC sp_OAMethod @oauth2, 'StartAuth', @url OUT
    EXEC sp_OAGetProperty @oauth2, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @oauth2, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @oauth2
        RETURN
      END

    DECLARE @http int
    -- Use "Chilkat_9_5_0.Http" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Http', @http OUT

    -- At this point, your application should load the URL in a browser.
    -- For example, 
    -- in C#: System.Diagnostics.Process.Start(url);
    -- in Java: Desktop.getDesktop().browse(new URI(url));
    -- in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
    --              wsh.Run url
    -- in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
    -- in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
    -- The GitHub account owner would interactively accept or deny the authorization request.

    -- Add the code to load the url in a web browser here...
    -- Add the code to load the url in a web browser here...
    -- Add the code to load the url in a web browser here...

    -- Now wait for the authorization.
    -- We'll wait for a max of 120 seconds.
    DECLARE @numMsWaited int
    SELECT @numMsWaited = 0
    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    WHILE (@numMsWaited < 120000) and (@iTmp0 < 3)
      BEGIN
        EXEC sp_OAMethod @oauth2, 'SleepMs', NULL, 100
        SELECT @numMsWaited = @numMsWaited + 100
      END

    -- If there was no response from the browser within 30 seconds, then 
    -- the AuthFlowState will be equal to 1 or 2.
    -- 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
    -- 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
    -- In that case, cancel the background task started in the call to StartAuth.
    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    IF @iTmp0 < 3
      BEGIN
        EXEC sp_OAMethod @oauth2, 'Cancel', @success OUT

        PRINT 'No response from the browser!'
        EXEC @hr = sp_OADestroy @oauth2
        EXEC @hr = sp_OADestroy @http
        RETURN
      END

    -- Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
    -- The possible AuthFlowState values are:
    -- 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
    -- 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
    -- 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    IF @iTmp0 = 5
      BEGIN

        PRINT 'OAuth2 failed to complete.'
        EXEC sp_OAGetProperty @oauth2, 'FailureInfo', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @oauth2
        EXEC @hr = sp_OADestroy @http
        RETURN
      END

    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    IF @iTmp0 = 4
      BEGIN

        PRINT 'OAuth2 authorization was denied.'
        EXEC sp_OAGetProperty @oauth2, 'AccessTokenResponse', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @oauth2
        EXEC @hr = sp_OADestroy @http
        RETURN
      END

    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    IF @iTmp0 <> 3
      BEGIN

        EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
        PRINT 'Unexpected AuthFlowState:' + @iTmp0
        EXEC @hr = sp_OADestroy @oauth2
        EXEC @hr = sp_OADestroy @http
        RETURN
      END


    PRINT 'OAuth2 authorization granted!'

    EXEC sp_OAGetProperty @oauth2, 'AccessToken', @sTmp0 OUT
    PRINT 'Access Token = ' + @sTmp0

    -- Get the full JSON response:
    DECLARE @json int
    -- Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @json OUT

    EXEC sp_OAGetProperty @oauth2, 'AccessTokenResponse', @sTmp0 OUT
    EXEC sp_OAMethod @json, 'Load', @success OUT, @sTmp0
    EXEC sp_OASetProperty @json, 'EmitCompact', 0
    EXEC sp_OAMethod @json, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    -- The JSON response looks like this:

    -- {
    --   "token_type": "Bearer",
    --   "scope": "user_impersonation",
    --   "expires_in": "3599",
    --   "ext_expires_in": "0",
    --   "expires_on": "1524783438",
    --   "not_before": "1524779538",
    --   "resource": "https://mydomain.api.crm.dynamics.com",
    --   "access_token": "...",
    --   "refresh_token": "...",
    --   "id_token": "..."
    -- }

    -- If an "expires_on" member does not exist, then add the JSON member by
    -- getting the current system date/time and adding the "expires_in" seconds.
    -- This way we'll know when the token expires.
    EXEC sp_OAMethod @json, 'HasMember', @iTmp0 OUT, 'expires_on'
    IF @iTmp0 <> 1
      BEGIN
        DECLARE @dtExpire int
        -- Use "Chilkat_9_5_0.CkDateTime" for versions of Chilkat < 10.0.0
        EXEC @hr = sp_OACreate 'Chilkat.CkDateTime', @dtExpire OUT

        EXEC sp_OAMethod @dtExpire, 'SetFromCurrentSystemTime', @success OUT
        EXEC sp_OAMethod @json, 'IntOf', @iTmp0 OUT, 'expires_in'
        EXEC sp_OAMethod @dtExpire, 'AddSeconds', @success OUT, @iTmp0
        EXEC sp_OAMethod @dtExpire, 'GetAsUnixTimeStr', @sTmp0 OUT, 0
        EXEC sp_OAMethod @json, 'AppendString', @success OUT, 'expires_on', @sTmp0
      END

    EXEC sp_OAMethod @json, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    -- Save the JSON to a file for future requests.
    DECLARE @fac int
    -- Use "Chilkat_9_5_0.FileAccess" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.FileAccess', @fac OUT

    EXEC sp_OAMethod @json, 'Emit', @sTmp0 OUT
    EXEC sp_OAMethod @fac, 'WriteEntireTextFile', @success OUT, 'qa_data/tokens/hmrc.json', @sTmp0, 'utf-8', 0

    EXEC @hr = sp_OADestroy @oauth2
    EXEC @hr = sp_OADestroy @http
    EXEC @hr = sp_OADestroy @json
    EXEC @hr = sp_OADestroy @dtExpire
    EXEC @hr = sp_OADestroy @fac


END
GO