Connecting to Azure Data Lake Storage

Set AzureStorageAccount to your Azure Data Lake Storage account name.

Authenticating to Azure Data Lake Storage

You can authenticate to Azure Data Lake Storage via Access Key, Shared Access Signature (SAS), AzureAD user, Azure MSI, or Azure Service Principal.

Access Key

Set the following to authenticate with an Azure Access Key:

• AuthScheme: Set this to AccessKey.
• AzureAccessKey: Set this to the storage key associated with your Azure Data Lake Storage account.

Shared Access Signature (SAS)

Set the following to authenticate with an Shared Access Signature (SAS):

• AuthScheme: Set this to AzureStorageSAS.
• AzureSharedAccessSignature: Set this to the SAS associated with your Azure Blob Storage account.

Follow these steps to create a shared access signature using AzureSharedAccessSignature:

1. Sign into the Azure Portal with the credentials for your root account. (https://portal.azure.com/)
2. Click storage accounts and select the storage account you want to use.
3. Under settings, click Shared Access Signature.
4. Set the permissions.
5. Specify when you want the token to expire.
6. Click Generate SAS and copy the shared access signature it generates.
7. Set AzureSharedAccessSignature to the shared access signature from the previous step.

AzureAD User

AuthScheme must be set to AzureAD in all user account flows.

Desktop Applications

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

Get and Refresh the OAuth Access Token

After setting the following, you are ready to connect:

• OAuthClientId (custom applications only): Set this to the client Id assigned when you registered your app.
• OAuthClientSecret (custom applications only): Set this to the client secret assigned when you registered your app.
• CallbackURL (custom application only): Set this to the redirect URI defined when you registered your app. For example: http://localhost:33333

When you connect, the connector opens the Microsoft identity platform's OAuth endpoint in your default browser. Log in and grant permissions to the application. The connector refreshes the access token automatically when it expires.

Headless Machines

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

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

1. Choose one of these options:
   • If you are using the Embedded OAuth Application, call the GetOAuthAuthorizationURL stored procedure. Open the URL returned by the stored procedure in a browser.
   • If you are using a custom OAuth application, set 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.
2. Log in and grant permissions to the connector. You are then redirected to the redirect URI.

There will be a parameter called code appended to the redirect URI. Note the value of this parameter. 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.

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 noted verifier code (the value of the code parameter in the redirect URI).
• 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 persist the encrypted OAuth authentication values to the specified location.

Test the connection to generate the OAuth settings file, then 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 gives 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 install and create 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.

Test the connection to generate the OAuth settings file, then 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 the OAuth settings file you copied from the machine with the browser. 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.

1. Open the Subscriptions page by searching and selecting the Subscriptions service from the search bar.
2. Select the subscription to assign the application to.
3. Open the Access control (IAM) and select Add > Add role assignment to open the Add role assignment page.
4. 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.

Azure MSI

If you are connecting from an Azure VM with permissions for Azure Data Lake Storage, set AuthScheme to AzureMSI.

Azure Service Principal

If you would like to authenticate with a service principal instead of a client secret, it is also possible to authenticate with a client certificate. Set the following to authenticate:

• AuthScheme: Set this to AzureServicePrincipal.
• AzureTenant: Set this to the tenant you wish to connect to.
• OAuthGrantType: Set this to CLIENT.
• OAuthClientId: Set this to the Client Id in your app settings.
• OAuthJWTCert: Set this to the JWT Certificate store.
• OAuthJWTCertType: Set this to the type of the certificate store specified by OAuthJWTCert.