Connecting to SharePoint Online

Connecting to SharePoint Online (REST)

The following authentication schemes are supported for the REST API:

AzureAD
MSI
AzureServicePrincipal

AzureAD

Azure Active Directory (AzureAD) is a connection type that leverages OAuth to authenticate. OAuth requires the authenticating user to interact with Avro using an internet browser. The driver facilitates this in several ways as described below. Set your AuthScheme to AzureAD. The AzureAD flows described below assume that you have done so.

Your organization may require Admin Consent when authorizing a new AzureAD application for your Azure Tenant. In all AzureAD flows, any initial installation and use of an AzureAD application requires that an administrator approve the application for their Azure Tenant.

Desktop Applications

CData provides an embedded OAuth application that simplifies OAuth desktop authentication. Alternatively, you can create a custom AzureAD application. See Creating a Custom AzureAD App for information about creating custom applications and reasons for doing so.

For authentication, the only difference between the two methods is that you must set two additional connection properties when using custom AzureAD applications.

After setting the following connection properties, you are ready to connect:

InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
OAuthClientId: (custom applications only) Set this to the client Id in your application settings.
OAuthClientSecret: (custom applications only) Set this to the client secret in your application settings.
CallbackURL: Set this to the Redirect URL in your application settings.

When you connect the connector opens the OAuth endpoint in your default browser. Log in and grant permissions to the application. The connector then completes the OAuth process:

Extracts the access token from the callback URL and authenticates requests.
Obtains a new access token when the old one expires.
Saves OAuth values in OAuthSettingsLocation. These stored values persist across connections.

Web Applications

When connecting via a Web application, you need to create and register a custom AzureAD application with Avro. See Creating a Custom AzureAD App for more information about custom applications. You can then use the connector to acquire and manage the OAuth token values.

Get an OAuth Access Token

Set the following connection properties to obtain the OAuthAccessToken:

OAuthClientId: Set this to the client Id in your application settings.
OAuthClientSecret: Set this to the client secret in your application settings

Then call stored procedures to complete the OAuth exchange:

Call the GetOAuthAuthorizationURL stored procedure. Set the CallbackURL input to the callback URL you specified in your application settings. If necessary, set the Scope parameter to request custom permissions.
The stored procedure returns the URL to the OAuth endpoint.
Open the URL, log in, and authorize the application. You are redirected back to the callback URL.
Call the GetOAuthAccessToken stored procedure. Set the AuthMode input to WEB. Set the Verifier input to the "code" parameter in the query string of the callback URL. If necessary, set the Scope parameter to request custom permissions.

Once you have obtained the access and refresh tokens, you can connect to data and refresh the OAuth access token either automatically or manually.

Automatic Refresh of the OAuth Access Token

To have the driver automatically refresh the OAuth access token, set the following on the first data connection:

InitiateOAuth: Set this to REFRESH.
OAuthClientId: Set this to the client Id in your application settings.
OAuthClientSecret: Set this to the client secret in your application settings.
OAuthAccessToken: Set this to the access token returned by GetOAuthAccessToken.
OAuthRefreshToken: Set this to the refresh token returned by GetOAuthAccessToken.
OAuthSettingsLocation: Set this to the location where the connector saves the OAuth token values, which persist across connections.

On subsequent data connections, the values for OAuthAccessToken and OAuthRefreshToken are taken from OAuthSettingsLocation.

Manual Refresh of the OAuth Access Token

The only value needed to manually refresh the OAuth access token when connecting to data is the OAuth refresh token.

Use the RefreshOAuthAccessToken stored procedure to manually refresh the OAuthAccessToken after the ExpiresIn parameter value returned by GetOAuthAccessToken has elapsed, then set the following connection properties:

OAuthClientId: Set this to the client Id in your application settings.
OAuthClientSecret: Set this to the client secret in your application settings.

Then call RefreshOAuthAccessToken with OAuthRefreshToken set to the OAuth refresh token returned by GetOAuthAccessToken. After the new tokens have been retrieved, open a new connection by setting the OAuthAccessToken property to the value returned by RefreshOAuthAccessToken.

Finally, store the OAuth refresh token so that you can use it to manually refresh the OAuth access token after it has expired.

Headless Machines

To configure the driver to use OAuth with a user account on a headless machine, you need to authenticate on another device that has an internet browser.

Choose one of these two options:
- Option 1: Obtain the OAuthVerifier value as described in "Obtain and Exchange a Verifier Code" below.
- Option 2: Install the connector on another machine and transfer the OAuth authentication values after you authenticate through the usual browser-based flow, as described in "Transfer OAuth Settings" below.
Then configure the connector to automatically refresh the access token from the headless machine.

Option 1: Obtain and Exchange a Verifier Code

To obtain a verifier code, you must authenticate at the OAuth authorization URL.

Follow the steps below to authenticate from the machine with an internet browser and obtain the OAuthVerifier connection property.

Choose one of these options:
- If you are using the Embedded OAuth Application click Avro OAuth endpoint to open the endpoint in your browser.
- If you are using a custom OAuth application, create the Authorization URL by setting the following properties:
  - InitiateOAuth: Set to OFF.
  - OAuthClientId: Set to the client Id assigned when you registered your application.
  - OAuthClientSecret: Set to the client secret assigned when you registered your application.
  Then call the GetOAuthAuthorizationURL stored procedure with the appropriate CallbackURL. Open the URL returned by the stored procedure in a browser.
Log in and grant permissions to the connector. You are then redirected to the callback URL, which contains the verifier code.
Save the value of the verifier code. Later you will set this in the OAuthVerifier connection property.

Next, you need to exchange the OAuth verifier code for OAuth refresh and access tokens. Set the following properties:

On the headless machine, set the following connection properties to obtain the OAuth authentication values:

InitiateOAuth: Set this to REFRESH.
OAuthVerifier: Set this to the verifier code.
OAuthClientId: (custom applications only) Set this to the client Id in your custom OAuth application settings.
OAuthClientSecret: (custom applications only) Set this to the client secret in the custom OAuth application settings.
OAuthSettingsLocation: Set this to the location of the file where the driver saves the OAuth token values that persist across connections.

After the OAuth settings file is generated, you need to re-set the following properties to connect:

InitiateOAuth: Set this to REFRESH.
OAuthClientId: (custom applications only) Set this to the client Id assigned when you registered your application.
OAuthClientSecret: (custom applications only) Set this to the client secret assigned when you registered your application.
OAuthSettingsLocation: Set this to the location containing the encrypted OAuth authentication values. Make sure this location grants read and write permissions to the connector to enable the automatic refreshing of the access token.

Option 2: Transfer OAuth Settings

Prior to connecting on a headless machine, you need to create and install a connection with the driver on a device that supports an internet browser. Set the connection properties as described in "Desktop Applications" above.

After completing the instructions in "Desktop Applications", the resulting authentication values are encrypted and written to the location specified by OAuthSettingsLocation. The default filename is OAuthSettings.txt.

Once you have successfully tested the connection, copy the OAuth settings file to your headless machine.

On the headless machine, set the following connection properties to connect to data:

InitiateOAuth: Set this to REFRESH.
OAuthClientId: (custom applications only) Set this to the client Id assigned when you registered your application.
OAuthClientSecret: (custom applications only) Set this to the client secret assigned when you registered your application.
OAuthSettingsLocation: Set this to the location of your OAuth settings file. Make sure this location gives read and write permissions to the connector to enable the automatic refreshing of the access token.

Azure Service Principal

The authentication as an Azure Service Principal is handled via the OAuth Client Credentials flow. It does not involve direct user authentication. Instead, credentials are created for just the application itself. All tasks taken by the app are done without a default user context, but based on the assigned roles. The application access to the resources is controlled through the assigned roles' permissions.

Create an AzureAD App and an Azure Service Principal

When authenticating using an Azure Service Principal, you must create and register an Azure AD application with an Azure AD tenant. See Creating an Azure AD Application for more details.

In your App Registration in portal.azure.com, navigate to API Permissions and select the Microsoft Graph permissions. There are two distinct sets of permissions: Delegated permissions and Application permissions. The permissions used during client credential authentication are under Application Permissions.

Assign a role to the application

To access resources in your subscription, you must assign a role to the application.

Open the Subscriptions page by searching and selecting the Subscriptions service from the search bar.
Select the subscription to assign the application to.
Open the Access control (IAM) and select Add > Add role assignment to open the Add role assignment page.
Select Owner as the role to assign to your created Azure AD app.

Complete the Authentication Choose whether to use a client secret or a certificate and follow the relevant steps below.

Client Secret

Set these connection properties:

AuthScheme: AzureServicePrincipal to use a client secret.
InitiateOAuth: GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
AzureTenant: The tenant you want to connect to.
OAuthClientId: The client Id in your application settings.
OAuthClientSecret: The client secret in your application settings.

Certificate

Set these connection properties:

AuthScheme: AzureServicePrincipalCert to use a certificate.
InitiateOAuth: GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
AzureTenant: The tenant you want to connect to.
OAuthJWTCert: The JWT Certificate store.
OAuthJWTCertType: The type of the certificate store specified by OAuthJWTCert.

You are now ready to connect. Authentication with client credentials takes place automatically like any other connection, except there is no window opened prompting the user. Because there is no user context, there is no need for a browser popup. Connections take place and are handled internally.

MSI

If you are running Avro on an Azure VM, you can leverage Managed Service Identity (MSI) credentials to connect:

AuthScheme: Set this to AzureMSI.

The MSI credentials are automatically obtained for authentication.

Azure Service Principal

When authenticating using an Azure Service Principal, you must register an application with an Azure AD tenant.

Assign a role to the application

To access resources in your subscription, you must assign a role to the application.

Open the Subscriptions page by searching and selecting the Subscriptions service from the search bar.
Select the particular subscription to assign the application to.
Open the Access control (IAM) and select Add > Add role assignment to open the Add role assignment page.
Select Owner as the role to assign to your created Azure AD app.

Authenticate with an Azure Service Principal

You are ready to connect after setting one of the below connection properties groups, depending on the configured app authentication (client secret or certificate).

Before choosing client secret or certicate authentication, set the following:

AuthScheme: Set this to the AzureServicePrincipal in your app settings.
InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
AzureTenant: Set this to the tenant you wish to connect to.
OAuthClientId: Set this to the client Id in your app settings.
OAuthGrantType: Set this to CLIENT.

Option 1: Authenticating using a Client Secret

Set the following to authenticate with a client secret:

OAuthClientId: Set this to the client Id in your app settings.
OAuthClientSecret: Set this to the client secret in your app settings.

Option 2: Authenticating using a JWT Certificate

Set the following to authenticate with a JWT Certificate:

OAuthJWTCert: Set this to the JWT Certificate store.
OAuthJWTCertType: Set this to the type of the certificate store specified by OAuthJWTCert.