(SQL Server) OAuth2 for a GMail using a JSON Service Account Key

Demonstrates how get an OAuth2 access token for GMail (Google Service Account) using a JSON private key.

After the access token is obtained, it may be used to send email. When the access token expires, a new access token needs to be obtained (using this same procedure).

Note: This is for OAuth2 using Google Service account keys.

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.

    -- First load the JSON key into a string.
    DECLARE @fac int
    -- Use "Chilkat_9_5_0.FileAccess" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.FileAccess', @fac OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @jsonKey nvarchar(4000)
    EXEC sp_OAMethod @fac, 'ReadEntireTextFile', @jsonKey OUT, 'qa_data/googleApi/ChilkatTest-ab2ecd52ef98.json', 'utf-8'
    EXEC sp_OAGetProperty @fac, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @fac, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @fac
        RETURN
      END

    -- A JSON private key should look like this:

    -- 	{
    -- 	  "type": "service_account",
    -- 	  "project_id": "chilkattest-1350",
    -- 	  "private_key_id": "fa2e36ee26986eab628b59868af8bec1d1c64c38",
    -- 	  "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvgIjFa...28N64N2n1E4FYzBZjSdy\n-----END PRIVATE KEY-----\n",
    -- 	  "client_email": "598922945226-00rb0ppfg0sndajo6bhvd4v17jtj2d3a@developer.gserviceaccount.com",
    -- 	  "client_id": "598922945226-00rb0ppfg0snd9jo7bhvd4v17jtj2d3a.apps.googleusercontent.com",
    -- 	  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
    -- 	  "token_uri": "https://accounts.google.com/o/oauth2/token",
    -- 	  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
    -- 	  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/598922945226-00rb0ppfg0sndajo6bhvd4v17jtj2d3a%40developer.gserviceaccount.com"
    -- 	}

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

    EXEC sp_OASetProperty @gAuth, 'JsonKey', @jsonKey

    -- Choose a scope.
    EXEC sp_OASetProperty @gAuth, 'Scope', 'https://mail.google.com/'

    -- Request an access token that is valid for this many seconds.
    EXEC sp_OASetProperty @gAuth, 'ExpireNumSeconds', 3600

    -- If the application is requesting delegated access:
    -- The email address of the user for which the application is requesting delegated access,
    -- then set the email address here. (Otherwise leave it empty.)
    EXEC sp_OASetProperty @gAuth, 'SubEmailAddress', ''

    -- Connect to www.googleapis.com using TLS (TLS 1.2 is the default.)
    -- The Chilkat socket object is used so that the connection can be established
    -- through proxies or an SSH tunnel if desired.
    DECLARE @tlsSock int
    -- Use "Chilkat_9_5_0.Socket" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Socket', @tlsSock OUT

    DECLARE @success int
    EXEC sp_OAMethod @tlsSock, 'Connect', @success OUT, 'www.googleapis.com', 443, 1, 5000
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @tlsSock, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @fac
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @tlsSock
        RETURN
      END

    -- Send the request to obtain the access token.
    EXEC sp_OAMethod @gAuth, 'ObtainAccessToken', @success OUT, @tlsSock
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @gAuth, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @fac
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @tlsSock
        RETURN
      END

    -- Examine the access token:

    EXEC sp_OAGetProperty @gAuth, 'AccessToken', @sTmp0 OUT
    PRINT 'Access Token: ' + @sTmp0

    -- Now that we have the access token, it may be used to send email
    -- while it remains valid.  Once the access token expires, a new access token 
    -- should be obtained using the same code as above.

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

    -- Set the properties for the GMail SMTP server:
    EXEC sp_OASetProperty @mailman, 'SmtpHost', 'smtp.gmail.com'
    EXEC sp_OASetProperty @mailman, 'SmtpPort', 587
    EXEC sp_OASetProperty @mailman, 'StartTLS', 1

    EXEC sp_OASetProperty @mailman, 'SmtpUsername', 'YOUR_GOOGLE_APPS_USER_EMAIL_ADDRESS'
    EXEC sp_OAGetProperty @gAuth, 'AccessToken', @sTmp0 OUT
    EXEC sp_OASetProperty @mailman, 'OAuth2AccessToken', @sTmp0

    -- Create a new email object
    DECLARE @email int
    -- Use "Chilkat_9_5_0.Email" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Email', @email OUT

    EXEC sp_OASetProperty @email, 'Subject', 'This is a test'
    EXEC sp_OASetProperty @email, 'Body', 'This is a test'
    EXEC sp_OASetProperty @email, 'From', 'YOUR NAME <YOUR_GOOGLE_APPS_USER_EMAIL_ADDRESS>'
    EXEC sp_OAMethod @email, 'AddTo', @success OUT, 'Chilkat Admin', 'admin@chilkatsoft.com'
    -- To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

    -- Call SendEmail to connect to the SMTP server and send.
    -- The connection (i.e. session) to the SMTP server remains
    -- open so that subsequent SendEmail calls may use the
    -- same connection.  
    EXEC sp_OAMethod @mailman, 'SendEmail', @success OUT, @email
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @mailman, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @fac
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @tlsSock
        EXEC @hr = sp_OADestroy @mailman
        EXEC @hr = sp_OADestroy @email
        RETURN
      END

    -- You may close the connection here.  If the connection is kept open, 
    -- the next call to mailman.SendEmail will continue using the already-established connection
    -- (and automatically re-connect if needed).
    EXEC sp_OAMethod @mailman, 'CloseSmtpConnection', @success OUT
    IF @success <> 1
      BEGIN

        PRINT 'Connection to SMTP server not closed cleanly.'
      END


    PRINT 'Email Sent via GMail using an OAuth2 Service Account Key.'

    EXEC @hr = sp_OADestroy @fac
    EXEC @hr = sp_OADestroy @gAuth
    EXEC @hr = sp_OADestroy @tlsSock
    EXEC @hr = sp_OADestroy @mailman
    EXEC @hr = sp_OADestroy @email


END
GO