Connecting to SAP Gateway
In addition to authenticating, set the following connection properties to access SAP Gateway tables.
- Url: Set this to the URL of your environment, or to the full URL of the service. For example, the full url might appear as: https://sapes5.sapdevcenter.com/sap/opu/odata/IWBEP/GWSAMPLE_BASIC/. In this example, the environment url would just be: https://sapes5.sapdevcenter.com.
- Namespace: Set the appropriate Service Namespace. In the example above, IWBEP is the namespace. It is optional if the full url to the service is specified.
- Service: Set this to the service you want to retrieve data from. In the example above, the service is GWSAMPLE_BASIC. It is not required if the full url is specified.
Authenticating to SAP Gateway
SAP Gateway allows both basic and OAuth 2.0 authentication. You can use basic authentication to connect to your own account, or you can use OAuth to enable other users to retrieve data from your service with their accounts.
Authenticate via Basic Authentication
In basic authentication, you use your login credentials to connect. Set the following properties:
- User: This is the username you use to log in to SAP Gateway.
- Password: This is the password you use to log in to SAP Gateway.
Using OAuth Authentication
OAuth requires the authenticating user to interact with SAP Gateway using the browser. The provider facilitates this in various ways as described below.
Custom Credentials
You can register an app to obtain the OAuthClientId and OAuthClientSecret.
NOTE : The password you choose when creating a service user as explained in Creating a Custom OAuth App, must be provided via OAuthClientSecret property.
When to Create a Custom OAuth App
You need to create a custom OAuth app in order to connect to SAP Gateway.
Creating a Custom OAuth App
See Creating a Custom OAuth App for information on how to create a custom app.
Custom Credentials
When to Use a Custom OAuth App
Creating a custom OAuth app is required all cases when connecting via OAuth.Desktop Authentication with a Custom OAuth App
Follow the steps below to authenticate with the credentials for a custom OAuth app. See Creating a Custom OAuth App for more information.After setting the following, you are ready to connect:
- OAuthClientId: Set this to the client Id assigned when you registered your app.
- OAuthClientSecret: Set this to the client secret assigned when you registered your app.
- Scope: Set this to the permissions you specified during Creating a Custom OAuth App.
- CallbackURL: Set this to the redirect URI defined when you registered your app.
- InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
- Extracts the access token from the callback URL and authenticates requests.
- Refreshes the access token when it expires.
- Saves OAuth values in OAuthSettingsLocation to be persisted across connections.
Web Authentication with a Custom OAuth App
When connecting via a Web application, you need to register a custom OAuth app with SAP Gateway. See Creating a Custom OAuth App. You can then use the provider to get 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 app settings.
- OAuthClientSecret: Set this to the Client Secret in your app settings.
- Scope: Set this to the permissions you specified during Creating a Custom OAuth App.
You can then call stored procedures to complete the OAuth exchange:
-
Call the GetOAuthAuthorizationURL stored procedure. Set the AuthMode input to WEB and set the CallbackURL input to the Redirect URI you specified in your app settings.
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.
Refresh the OAuth Access Token
You can set InitiateOAuth to REFRESH to automatically refresh the OAuth access token when it expires, or you can call the RefreshOAuthAccessToken stored procedure to refresh the token manually.
Automatic Refresh
To refresh the token with InitiateOAuth, set the following on the first data connection:
- OAuthAccessToken: Set this to the access token returned by GetOAuthAccessToken.
- InitiateOAuth: Set this to REFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
- OAuthSettingsLocation: Set this to the path where the provider will save the OAuth values, to be persisted across connections.
- OAuthClientId: Set this to the Client Id in your app settings.
- OAuthClientSecret: Set this to the Client Secret in your app settings.
- Scope: Set this to the permissions you specified during Creating a Custom OAuth App.
- OAuthRefreshToken: Set this to the refresh token returned by GetOAuthAccessToken.
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InitiateOAuthOn subsequent data connections, set the following:
- OAuthSettingsLocation
Manual Refresh
You can use the RefreshOAuthAccessToken stored procedure to manually refresh the OAuthAccessToken. Call the stored procedure after the ExpiresIn parameter value returned by GetOAuthAccessToken has elapsed. You need the following connection properties to be set:
- OAuthClientId: Set this to the Client Id in your app settings.
- OAuthClientSecret: Set this to the Client Secret in your app settings.
- Scope: Set this to the permissions you specified during Creating a Custom OAuth App.
You can then call RefreshOAuthAccessToken with the following parameter set:
- OAuthRefreshToken: Set this to the OAuthRefreshToken returned by GetOAuthAccessToken.
Headless Machines
Using OAuth on a Headless Machine
To create SAP Gateway data sources on headless servers or other machines on which the provider cannot open a browser, you need to authenticate from another machine. Authentication is a two-step process.
- Instead of installing the provider on another machine, you can follow the steps below to obtain the OAuthVerifier value. Or, you can install the provider on another machine and transfer the OAuth authentication values, after you authenticate through the usual browser-based flow.
- You can then configure the provider to automatically refresh the access token from the headless machine.
Using the Credentials for a Custom OAuth App
Create a Custom OAuth App
Creating a custom OAuth app is required in the headless OAuth flow.
See Creating a Custom OAuth App for a procedure. You can then follow the procedures below to authenticate and connect to data.
Obtain a Verifier Code
Set the following properties on the headless machine:
- InitiateOAuth: Set this to OFF.
- OAuthClientId: Set this to the Client Id in your app settings.
- OAuthClientSecret: Set this to the Client Secret in your app settings.
- Scope: Set this to the permissions you specified during Creating a Custom OAuth App.
You can then follow the steps below to authenticate from another machine and obtain the OAuthVerifier connection property.
- Call the GetOAuthAuthorizationURL stored procedure with the CallbackURL input parameter set to the exact Redirect URI you specified in your app settings.
- Open the returned URL in a browser. Log in and grant permissions to the provider. You are then redirected to the callback URL, which contains the verifier code.
- Save the value of the verifier code. You will set this in the OAuthVerifier connection property.
On the headless machine, set the following connection properties to obtain the OAuth authentication values:
- OAuthVerifier: Set this to the verifier code.
- OAuthSettingsLocation: Set this to persist the encrypted OAuth authentication values to the specified file.
- InitiateOAuth: Set this to REFRESH.
After the OAuth settings file is generated, set the following properties to connect to data:
- OAuthSettingsLocation: Set this to the file containing the encrypted OAuth authentication values. Make sure this file gives read and write permissions to the provider to enable the automatic refreshing of the access token.
- InitiateOAuth: Set this to REFRESH.
Transfer OAuth Settings
Follow the steps below to install the provider on another machine, authenticate, and then transfer the resulting OAuth values.
On a second machine, install the provider and connect with the following properties set:
- OAuthSettingsLocation: Set this to a writable text file.
- InitiateOAuth: Set this to GETANDREFRESH.
- OAuthClientId: Set this to the client Id assigned when you registered your app.
- OAuthClientSecret: Set this to the client secret assigned when you registered your app.
- Scope: Set this to the permissions you specified during Creating a Custom OAuth App.
- CallbackURL: Set this to the Redirect URI you specified in your app settings.
Test the connection to authenticate. The resulting authentication values are written, encrypted, to the path specified by OAuthSettingsLocation. 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.
- OAuthSettingsLocation: Set this to the path to your OAuth settings file. Make sure this file gives read and write permissions to the provider to enable the automatic refreshing of the access token.
Creating a Custom OAuth App
When to Create a Custom OAuth App
Creating a custom OAuth app is required in all cases.
To create a custom OAuth app, follow the steps in this article, OAuth 2.0 Client Registration
Customizing the SSL Configuration
By default, the provider attempts to negotiate SSL/TLS by checking the server's certificate against the system's trusted certificate store. To specify another certificate, see the SSLServerCert property for the available formats to do so.
Connecting Through a Firewall or Proxy
HTTP Proxies
To connect through the Windows system proxy, you do not need to set any additional connection properties. To connect to other proxies, set ProxyAutoDetect to false.
In addition, to authenticate to an HTTP proxy, set ProxyAuthScheme, ProxyUser, and ProxyPassword, in addition to ProxyServer and ProxyPort.
Other Proxies
Set the following properties:
- To use a proxy-based firewall, set FirewallType, FirewallServer, and FirewallPort.
- To tunnel the connection, set FirewallType to TUNNEL.
- To authenticate, specify FirewallUser and FirewallPassword.
- To authenticate to a SOCKS proxy, additionally set FirewallType to SOCKS5.
Troubleshooting the Connection
To show provider activity from query execution to network traffic, use Logfile and Verbosity. The examples of common connection errors below show how to use these properties to get more context. Contact the support team for help tracing the source of an error or circumventing a performance issue.
- Authentication errors: Typically, recording a Logfile at Verbosity 4 is necessary to get full details on an authentication error.
- Queries time out: A server that takes too long to respond will exceed the provider's client-side timeout. Often, setting the Timeout property to a higher value will avoid a connection error. Another option is to disable the timeout by setting the property to 0. Setting Verbosity to 2 will show where the time is being spent.
- The certificate presented by the server cannot be validated: This error indicates that the provider cannot validate the server's certificate through the chain of trust. If you are using a self-signed certificate, there is only one certificate in the chain.
To resolve this error, you must verify yourself that the certificate can be trusted and specify to the provider that you trust the certificate. One way you can specify that you trust a certificate is to add the certificate to the trusted system store; another is to set SSLServerCert.