Set up authentication for the SAP BTP edition of ABAP SDK for Google Cloud

SAP BTP edition v1.0

• SAP BTP edition v1.0
• On-premises or any cloud edition v1.8

This document describes how to authenticate to Google Cloud from the SAP BTP edition of ABAP SDK for Google Cloud.

Applications developed using the SAP BTP edition of ABAP SDK for Google Cloud require authentication to connect to Google Cloud APIs.

For authentication and authorization to access Google Cloud APIs, the SDK mainly uses tokens. In addition, the SDK also supports API keys to authenticate to Google Cloud APIs that use API keys. Only a few Google Cloud APIs use API keys for authentication. For example, Google Maps Platform. Review the authentication documentation for the service or API that you want to use to determine whether it supports API keys.

Depending on the Google Cloud APIs that you need to access, you can choose an appropriate method of authentication. The following list summarizes different methods of authentication supported by the SDK:

• Authentication using tokens through Workload Identity Federation
• Authentication using API key stored in Secret Manager

Authentication using tokens through Workload Identity Federation

Workload Identity Federation follows the OAuth 2.0 token exchange specification. You provide a credential from your identity provider (IdP) to the Security Token Service, which verifies the identity on the credential, and then returns a federated token in exchange. You can use this token to impersonate a service account and obtain a short-lived OAuth 2.0 access token. The short-lived access token lets you call any Google Cloud APIs that the service account has access to.

For authentication using tokens through Workload Identity Federation, enable the following Google Cloud APIs:

• IAM Service Account Credentials API
• Security Token Service API

For information about how to enable Google Cloud APIs, see Enabling APIs.

For authentication using tokens through Workload Identity Federation, the high-level configuration steps are as follows:

1. In SAP BTP, create an Authorization and Trust (XSUAA) service instance.
2. In Google Cloud, create a service account.
3. In Google Cloud, configure Workload Identity Federation.
4. In SAP BTP, configure ABAP SDK for Google Cloud to use Workload Identity Federation.

Create an Authorization and Trust (XSUAA) service instance

To provide the necessary services to the back-end application, create an Authorization and Trust (XSUAA) service instance by performing the following steps:

1. Sign in to the SAP BTP Cockpit. For more information, see the SAP page Access the Cockpit.
2. Select your subaccount.

3. Create an XSUAA service instance:

   1. Go to Services > Service Marketplace.
   2. Search for and select Authorization & Trust Management Service (XSUAA).
   3. Click Create.

   4. In the New Instance or Subscription dialog that appears, enter a value for the following fields:

      • Plan: select Application.
      • Runtime environment: select Cloud Foundry.
      • Space: select a space name.
      • Instance name: enter a name for the XSUAA service instance.

   5. Click Create.

4. Create a service key:

   1. Go to Instances and Subscription > Instances.
   2. Select the XSUAA service instance that you created in the previous step, and click the Service keys tab.
   3. Click Create.
   4. Enter a service key name and click Create.
   5. For the newly created service key, click the Actions () menu, and select View.

   6. From the service key credentials, make a note of the following:

      • url
      • clientid
      • clientsecret

   You need these service key credentials when configuring authentication to Google Cloud.

Create a service account

In the Google Cloud console, create an IAM service account. This service account must be a principal in the Google Cloud project that contains the Google Cloud APIs that you plan to consume using the SDK.

1. In the Google Cloud console, select the project where you want to create the service account.

   • If you create the service account in the same project that contains the Google Cloud APIs, then the service account is added as a principal to the project automatically.

   • If you create the service account in a project other than the project where the Google Cloud APIs are enabled, then you need to add the service account to that project in an additional step. For more information, see Add the service account to the Google Cloud project.

2. Create a service account for authentication and authorization to access Google Cloud APIs.

   Go to Service accounts

   For information about how to create a service account, see Create a service account.

3. In the Google Cloud console, grant the service account the required IAM roles to access the API functionality. To understand the role requirement for Google Cloud APIs, see the individual API documentation and follow the principle of least privilege. For more information about API specific predefined roles, see IAM basic and predefined roles reference.

4. If you created the service account in a different project than the project that contains the Google Cloud APIs that you plan to consume using the SDK, then note the name of the service account. You specify the name when you add the service account to that project.

Add the service account to the Google Cloud project

If you created the service account for ABAP SDK for Google Cloud in a project other than the project that contains the Google Cloud APIs that you plan to consume using the SDK, then you need to add the service account to the Google Cloud project that contains the Google Cloud APIs.

If you created the service account in the same project that contains the Google Cloud APIs, then you can skip this step.

To add an existing service account to the Google Cloud project that contains the Google Cloud APIs, perform the following steps:

1. In the Google Cloud console, go to the IAM Permissions page.

   Go to IAM permissions

2. Confirm that the name of the project that contains the target Google Cloud APIs is displayed near the top of the page. For example:

   Permissions for project 'PROJECT_NAME'

   If it is not, then switch projects.

3. On the IAM Permissions page, click Grant access.

4. In the Grant access to 'PROJECT_NAME' dialog that appears, perform the following steps:

   1. In the New principals field, specify the name of the service account.

   2. In the Select a role field, specify a relevant role. For example, for Pub/Sub, to modify topics and subscriptions, and access to publish and consume messages, you can specify the role Pub/Sub Editor (roles/pubsub.editor).

      For more details about API specific predefined roles, see IAM basic and predefined roles reference.

   3. Add additional roles as required for your API usage. We recommend implementing the principle of least privilege.

   4. Click Save. The service account appears in the list of project principals on the IAM page.

The service account can now be used to access Google Cloud APIs in this project.

Configure Workload Identity Federation

To get the permissions that you need to configure Workload Identity Federation, ask your administrator to grant you the following IAM roles on the project:

• Workload Identity Pool Admin (roles/iam.workloadIdentityPoolAdmin)
• Service Account Admin (roles/iam.serviceAccountAdmin)

For more information about granting roles, see Manage access.

To configure Workload Identity Federation, perform the following steps:

1. In the Google Cloud console, go to the New workload provider and pool page.

   Go to New workload provider and pool

2. In the Create an identity pool section, enter a value for the following fields:

   • Name: name for the pool. The name is also used as the pool ID. You can't change the pool ID later.
   • Description: text that describes the purpose of the pool.

3. Click Continue.

4. Under Add a provider to pool, add the provider settings:

   1. In the Select a provider field, select OpenID Connect (OIDC).

   2. Enter the following provider details:

      • Provider name: enter a name for the provider.
      • Issuer(URL): enter the URL from the service key credentials that you noted when you created the XSUAA service instance. Append /oauth/token to the URL.
      • Audience: select Allowed audience and enter the client ID from the service key credentials that you noted when you created the XSUAA service instance.

5. Click Continue.

6. Under Configure provider attributes, in the OIDC 1 field, enter assertion.sub.

7. Click Save.

8. Make a note of the following:

   • Pool ID
   • Provider ID

   You need these IDs when configuring authentication in the SDK configuration Fiori app.

Allow external identities to impersonate the service account

To impersonate service accounts from federated workloads, grant the Workload Identity User (roles/iam.workloadIdentityUser) on the service account. For more information about granting roles, see Manage access.

To allow external identities to impersonate a service account, perform the following:

1. In the Google Cloud console, go to the Workload Identity Pools page.

   Go to Workload Identity Pools

2. Select the workload identity pool that you created in the configure Workload Identity Federation section.

3. To grant access to the workload identity pool, click Grant access.

4. In the Service account list, select the service account that has access to Google Cloud APIs. If you use multiple service accounts, then add them all here.

5. In the Attribute name field, select Subject.

6. In the Attribute value field, enter the client ID from the service key credentials that you noted when you created the XSUAA service instance.

7. Click Save.

8. In the Configure your application dialog that appears, click Dismiss.

Configure ABAP SDK for Google Cloud to use Workload Identity Federation

You create communication management artifacts using the SAP communication management apps.

To create communication management artifacts for authentication using the XSUAA service and Workload Identity Federation, you use the communication scenario /GOOG/COM_SDK_WIF that is shipped with the ABAP SDK for Google Cloud.

Later, you use the SDK configuration Fiori app to create a communication map. In the communication map, you define a unique client key that you use in your ABAP program for authentication to Google Cloud.

1. Access the SAP Fiori launchpad of the BTP ABAP system where the ABAP SDK for Google Cloud is installed.
2. Go to All spaces > Administration > Communication Management.
3. Create a communication system:
   1. Open the Communication Systems app.
   2. Click New.
   3. In the New Communication System dialog that appears, enter a value for the following fields:
      • System ID: enter a system ID.
      • System name: enter a system name.
   4. Click Create.
   5. In the Host name field, enter the URL without https:// from the service key credentials that you noted when you created the XSUAA service instance.
   6. In the Port field, enter 443.
   7. On the Users for Outbound Communication tab, click Add.
   8. Provide the following details:
      • Authentication method: select User Name and Password.
      • User name/client ID: enter the client ID from the service key credentials that you noted when you created the XSUAA service instance.
      • Password: enter the client secret from the service key credentials that you noted when you created the XSUAA service instance.
   9. Click Save.

4. Create a communication arrangement:

   1. Open the Communication Arrangement app.
   2. Click New.

   3. In the New Communication Arrangement dialog that appears, enter a value for the following fields:

      • Scenario: select Authentication using Workload Identity Federation (/GOOG/COM_SDK_WIF).
      • Arrangement name: enter a name for the communication arrangement.

   4. Click Create.

   5. For the communication arrangement that appears, in the Communication System field, select the communication system that you created in the previous step.

   6. Provide the following details from the Configure Workload Identity Federation section:

      • Workload Identity Federation Pool ID: enter the workload identity federation pool ID.
      • Workload Identity Federation Provider ID: enter the workload identity federation provider ID.

   7. Under Outbound services, in the Path field, enter /oauth/token.

   8. Click Save.

5. Create a client key and a communication map:

   1. Go to the space that contains the Fiori apps for SDK configuration.
   2. Open the Google SDK: Main Configuration app.
   3. Click Create.
   4. In the Create dialog that appears, enter a client key name.
   5. Click Continue.
   6. Provide the following details:
      • Service account: enter the service account that is granted access to Google Cloud APIs.
      • Project ID: enter the Google Cloud project ID. For information about project ID, see Identifying projects.
      • Project number: enter the Google Cloud project number. For information about project number, see Identifying projects.
      • Authentication type: select W (Workload Identity Federation).
   7. For the communication map that appears, in the Communication arrangement field, select the communication arrangement that you created in the previous step.
   8. Click Create. A dialog appears confirming that you agree to use ABAP SDK for Google Cloud under standard Google Cloud terms.
   9. To validate the authentication configuration, click Check connection. A green check for an entry indicates successful configuration. In case of any errors, visit the troubleshooting page for guidance to resolve common errors.

Authentication using API key stored in Secret Manager

When using API keys for authentication to Google Cloud, you can securely store your API keys with the Secret Manager service of Google Cloud.

For authentication using API key stored in Secret Manager, enable the following Google Cloud APIs:

• Secret Manager API
• IAM Service Account Credentials API
• Security Token Service API

For information about how to enable Google Cloud APIs, see Enabling APIs.

To get the permissions that you need to configure Secret Manager and Workload Identity Federation, ask your administrator to grant you the following IAM roles on the project:

• Secret Manager Admin role (roles/secretmanager.admin)
• Workload Identity Pool Admin (roles/iam.workloadIdentityPoolAdmin)
• Service Account Admin (roles/iam.serviceAccountAdmin)

For authentication using API key stored in Secret Manager, the high-level configuration steps are as follows:

1. In SAP BTP, create an Authorization and Trust (XSUAA) service instance.
2. In Google Cloud, create a service account.
3. In Google Cloud, configure Workload Identity Federation.
4. In Google Cloud, create an API key.
5. In Google Cloud, create a secret and store the API key.
6. In SAP BTP, configure ABAP SDK for Google Cloud to use API key from Secret Manager.

When you're authenticating using an API key stored in Secret Manager, you can reuse the XSUAA service instance, service account, and Workload Identity Federation pool and provider that you created for authentication using tokens.

Create an API key

For authentication using API key, you need to create an API key. An API key string is an encrypted string, for example, AIzaSyDaGmWKa4JsXZ-HjGw7ISLn_3namBGewQe. ABAP SDK for Google Cloud uses the API key string in HTTP request to securely authenticate when calling a Google Cloud API.

Google Cloud provides multiple ways to create API keys.

To create API keys using the Google Cloud console, perform the following steps:

1. In the Google Cloud console, go to the Credentials page:

   Go to Credentials

2. Click Create Credentials and select API key from the menu.

   • The API key created dialog displays the API key string. Copy your key string and keep it secure. You need this API key to configure authentication to Google Cloud.

   • By default, API keys are unrestricted. We recommended that you restrict API keys by selecting the APIs to which this API key can be used. For more information about adding API restrictions, see Add API restrictions.

Create a secret and store the API key

1. In the Google Cloud console, go to the Secret Manager page.

   Go to Secret Manager

2. Click Create secret.

3. On the Create secret page, under Name, enter a name for the secret. A secret name can contain uppercase and lowercase letters, numerals, hyphens, and underscores. The maximum allowed length for a name is 255 characters.

4. In the Secret value field, enter the API key that you created in the Create an API key section.

5. Click Create secret. The contents of your secret are stored in a secret version.

6. Click the name of the secret that you created.

7. On the Versions tab that opens, make a note of the following:

   • Secret name
   • Version

   You need these secret details when configuring authentication to Google Cloud.

Configure ABAP SDK for Google Cloud to use API key from Secret Manager

You create communication management artifacts using the SAP communication management apps.

To create communication management artifacts for authentication using XSUAA service and Workload Identity Federation, you use the communication scenario /GOOG/COM_SDK_APIKSM that is shipped with the ABAP SDK for Google Cloud.

Later, you use the SDK configuration Fiori app to create a communication map. In the communication map, you define a unique client key that you use in your ABAP program for authentication to Google Cloud.

1. Access the SAP Fiori launchpad of the BTP ABAP system where the ABAP SDK for Google Cloud is installed.
2. Go to All spaces > Administration > Communication Management.
3. Create a communication system:
   1. Open the Communication Systems app.
   2. Click New.
   3. In the New Communication System dialog that appears, enter a value for the following fields:
      • System ID: enter a system ID.
      • System name: enter a system name.
   4. Click Create.
   5. In the Host name field, enter the URL without https:// from the service key credentials that you noted when you created the XSUAA service instance.
   6. In the Port field, enter 443.
   7. On the Users for Outbound Communication tab, click Add.
   8. Provide the following details:
      • Authentication method: select User Name and Password.
      • User name/client ID: enter the client ID from the service key credentials that you noted when you created the XSUAA service instance.
      • Password: enter the client secret from the service key credentials that you noted when you created the XSUAA service instance.
   9. Click Save.

4. Create a communication arrangement:

   1. Open the Communication Arrangement app.
   2. Click New.

   3. In the New Communication Arrangement dialog that appears, enter the following details:

      • Scenario: select Authentication using API Key with Secret Manager (/GOOG/COM_SDK_APIKSM).
      • Arrangement name: enter a name for the communication arrangement.

   4. Click Create.

   5. For the communication arrangement that appears, in the Communication System field, select the communication system that you created in the previous step.

   6. Under Additional properties, provide a value for the following properties:

      • Secret name: enter the name of the secret from the Create a secret and store the API key section.
      • Secret version: optionally, enter the version of the secret from the Create a secret and store the API key section. If you do not provide a version, then the API key from the latest secret version is used.
      • Workload Identity Federation Pool ID: enter the workload identity federation pool ID from the Configure Workload Identity Federation section.
      • Workload Identity Federation Provider ID: enter the workload identity federation provider ID from the Configure Workload Identity Federation section.

   7. Under Outbound services, in the Path field, enter /oauth/token.

   8. Click Save.

5. Create a client key and a communication map:

   1. Go to the space that contains the Fiori apps for SDK configuration.
   2. Open the Google SDK: Main Configuration app.
   3. Click Create.
   4. In the Create dialog that appears, enter a client key name.
   5. Click Continue.

   6. Provide the following details:

      • Service account: enter the service account that is granted access to Google Cloud APIs.
      • Project ID: enter the Google Cloud project ID. For information about project ID, see Identifying projects.
      • Project number: enter the Google Cloud project number. For information about project number, see Identifying projects.
      • Authentication type: select V (API Key using Secret Manager).

   7. For the communication map that appears, in the Communication arrangement field, select the communication arrangement that you created in the previous step.

   8. Click Create. A dialog appears confirming that you agree to use ABAP SDK for Google Cloud under standard Google Cloud terms.

   9. To validate the authentication configuration, click Check connection. A green check for an entry indicates successful configuration. In case of any errors, visit the troubleshooting page for guidance to resolve common errors.

Get support

If you need help resolving problems with the ABAP SDK for Google Cloud, then do the following:

• Refer to the ABAP SDK for Google Cloud troubleshooting guide.

• Ask your questions and discuss ABAP SDK for Google Cloud with the community on Cloud Forums.

• Collect all available diagnostic information and contact Cloud Customer Care. For information about contacting Customer Care, see Getting support for SAP on Google Cloud.