OAuth 2.0 authentication#

Dell Data Analytics Engine, powered by Starburst Enterprise platform (SEP) can be configured to enable OAuth 2.0 authentication over HTTPS for the Web UI and the JDBC driver. SEP uses the Authorization Code flow which exchanges an Authorization Code for a token. At a high level, the flow includes the following steps:

the SEP coordinator redirects a user’s browser to the Authorization Server
the user authenticates with the Authorization Server, and it approves the SEP’s permissions request
the user’s browser is redirected back to the SEP coordinator with an authorization code
the SEP coordinator exchanges the authorization code for a token

To enable OAuth 2.0 authentication for SEP, configuration changes are made on the SEP coordinator. No changes are required to the worker configuration; only the communication from the clients to the coordinator is authenticated.

Set the callback/redirect URL to https://<trino-coordinator-domain-name>/oauth2/callback, when configuring an OAuth 2.0 authorization server like an OpenID Connect (OIDC) provider.

Using TLS and a configured shared secret is required for OAuth 2.0 authentication.

OpenID Connect Discovery#

SEP supports reading Authorization Server configuration from OIDC provider configuration metadata document. During startup of the coordinator SEP retrieves the document and uses provided values to set corresponding OAuth2 authentication configuration properties:

authorization_endpoint -> http-server.authentication.oauth2.auth-url
token_endpoint -> http-server.authentication.oauth2.token-url
jwks_uri -> http-server.authentication.oauth2.jwks-url
userinfo_endpoint -> http-server.authentication.oauth2.userinfo-url
access_token_issuer -> http-server.authentication.oauth2.access-token-issuer

Warning

If the authorization server is issuing JSON Web Tokens (JWTs) and the metadata document contains userinfo_endpoint, SEP uses this endpoint to check the validity of OAuth2 access tokens. Since JWTs can be inspected locally, using them against userinfo_endpoint may result in authentication failure. In this case, set the http-server.authentication.oauth2.oidc.use-userinfo-endpoint configuration property to false (http-server.authentication.oauth2.oidc.use-userinfo-endpoint=false). This instructs SEP to ignore userinfo_endpoint and inspect tokens locally.

This functionality is enabled by default but can be turned off with: http-server.authentication.oauth2.oidc.discovery=false.

SEP server configuration#

Using the OAuth2 authentication requires the SEP coordinator to be secured with TLS.

The following is an example of the required properties that need to be added to the coordinator’s config.properties file:

http-server.authentication.type=oauth2

http-server.https.port=8443
http-server.https.enabled=true

http-server.authentication.oauth2.issuer=https://authorization-server.com
http-server.authentication.oauth2.client-id=CLIENT_ID
http-server.authentication.oauth2.client-secret=CLIENT_SECRET

To enable OAuth 2.0 authentication for the Web UI, the following property must be be added:

web-ui.authentication.type=OAUTH2

The following configuration properties are available:

OAuth2 configuration properties#
Property	Description
`http-server.authentication.type`	The type of authentication to use. Must be set to `oauth2` to enable OAuth2 authentication for the SEP coordinator.
`http-server.authentication.oauth2.issuer`	The issuer URL of the IdP. All issued tokens must have this in the `iss` field.
`http-server.authentication.oauth2.access-token-issuer`	The issuer URL of the IdP for access tokens, if different. All issued access tokens must have this in the `iss` field. Providing this value while OIDC discovery is enabled overrides the value from the OpenID provider metadata document. Defaults to the value of `http-server.authentication.oauth2.issuer`.
`http-server.authentication.oauth2.auth-url`	The authorization URL. The URL a user’s browser will be redirected to in order to begin the OAuth 2.0 authorization process. Providing this value while OIDC discovery is enabled overrides the value from the OpenID provider metadata document.
`http-server.authentication.oauth2.token-url`	The URL of the endpoint on the authorization server which SEP uses to obtain an access token. Providing this value while OIDC discovery is enabled overrides the value from the OpenID provider metadata document.
`http-server.authentication.oauth2.jwks-url`	The URL of the JSON Web Key Set (JWKS) endpoint on the authorization server. It provides SEP the set of keys containing the public key to verify any JSON Web Token (JWT) from the authorization server. Providing this value while OIDC discovery is enabled overrides the value from the OpenID provider metadata document.
`http-server.authentication.oauth2.userinfo-url`	The URL of the IdPs `/userinfo` endpoint. If supplied then this URL is used to validate the OAuth access token and retrieve any associated claims. This is required if the IdP issues opaque tokens. Providing this value while OIDC discovery is enabled overrides the value from the OpenID provider metadata document.
`http-server.authentication.oauth2.client-id`	The public identifier of the SEP client.
`http-server.authentication.oauth2.client-secret`	The secret used to authorize SEP client with the authorization server.
`http-server.authentication.oauth2.additional-audiences`	Additional audiences to trust in addition to the client ID which is always a trusted audience.
`http-server.authentication.oauth2.scopes`	Scopes requested by the server during the authorization challenge. See: https://tools.ietf.org/html/rfc6749#section-3.3
`http-server.authentication.oauth2.challenge-timeout`	Maximum duration of the authorization challenge. Default is `15m`.
`http-server.authentication.oauth2.state-key`	A secret key used by the SHA-256 HMAC algorithm to sign the state parameter in order to ensure that the authorization request was not forged. Default is a random string generated during the coordinator start.
`http-server.authentication.oauth2.user-mapping.pattern`	Regex to match against user. If matched, the user name is replaced with first regex group. If not matched, authentication is denied. Default is `(.*)` which allows any user name.
`http-server.authentication.oauth2.user-mapping.file`	File containing rules for mapping user. See User mapping for more information.
`http-server.authentication.oauth2.principal-field`	The field of the access token used for the SEP user principal. Defaults to `sub`. Other commonly used fields include `sAMAccountName`, `name`, `upn`, and `email`.
`http-server.authentication.oauth2.oidc.discovery`	Enable reading the OIDC provider metadata. Default is `true`.
`http-server.authentication.oauth2.oidc.discovery.timeout`	The timeout when reading OpenID provider metadata. Default is `30s`.
`http-server.authentication.oauth2.oidc.use-userinfo-endpoint`	Use the value of `userinfo_endpoint` in the provider metadata. When a `userinfo_endpoint` value is supplied this URL is used to validate the OAuth 2.0 access token, and retrieve any associated claims. This flag allows ignoring the value provided in the metadata document. Required for JWT access tokens which support local validation. Default is `true`.

You can optionally enable a client token authentication page in the Starburst Enterprise web UI that exposes a JWT for use with any clients that support OAuth 2.0 authentication with a JWT. To enable this page, set the following configuration property to true in the coordinator’s config.properties file:

web-ui.token-copy.enabled=true

Refresh tokens#

Refresh tokens allow you to securely control the length of user sessions within applications. The refresh token has a longer lifespan (TTL) and is used to refresh the access token that has a shorter lifespan. When refresh tokens are used in conjunction with access tokens, users can remain logged in for an extended duration without interruption by another login request.

In a refresh token flow, there are three tokens with different expiration times:

access token
refresh token
SEP-encrypted token that is a combination of the access and refresh tokens. The encrypted token manages the session lifetime with the timeout value that is set with the http-server.authentication.oauth2.refresh-tokens.issued-token.timeout property.

In the following scenario, the lifespan of the tokens issued by an IdP are:

access token 5m
refresh token 24h

Because the access token lifespan is only five minutes, SEP uses the longer lifespan refresh token to request another access token every five minutes on behalf of a user. In this case, the maximum http-server.authentication.oauth2.refresh-tokens.issued-token.timeout is twenty-four hours.

To use refresh token flows, the following property must be enabled in the coordinator configuration.

http-server.authentication.oauth2.refresh-tokens=true

Additional scopes for offline access might be required, depending on IdP configuration.

http-server.authentication.oauth2.scopes=openid,offline_access [or offline]

The following configuration properties are available:

OAuth2 configuration properties for refresh flow#
Property	Description
`http-server.authentication.oauth2.refresh-tokens.issued-token.timeout`	Expiration time for an issued token, which is the Trino-encrypted token that contains an access token and a refresh token. The timeout value must be less than or equal to the duration of the refresh token expiration issued by the IdP. Defaults to `1h`. The timeout value is the maximum session time for an OAuth2-authenticated client with refresh tokens enabled. For more details, see Troubleshooting.
`http-server.authentication.oauth2.refresh-tokens.issued-token.issuer`	Issuer representing the coordinator instance, that is referenced in the issued token, defaults to `Trino_coordinator`. The current Trino version is appended to the value. This is mainly used for debugging purposes.
`http-server.authentication.oauth2.refresh-tokens.issued-token.audience`	Audience representing this coordinator instance, that is used in the issued token. Defaults to `Trino_coordinator`.
`http-server.authentication.oauth2.refresh-tokens.secret-key`	Base64-encoded secret key used to encrypt the generated token. By default it’s generated during startup.

Troubleshooting#

To debug issues, change the log level for the OAuth 2.0 authenticator:

io.trino.server.security.oauth2=DEBUG

To debug issues with OAuth 2.0 authentication use with the web UI, set the following configuration property:

io.trino.server.ui.OAuth2WebUiAuthenticationFilter=DEBUG

This assumes the OAuth 2.0 authentication for the web UI is enabled as described in SEP server configuration.

The logged debug error for a lapsed refresh token is Tokens refresh challenge has failed.

Warning

If a refresh token lapses, the user session is interrupted and the user must reauthenticate by logging in again. Ensure you set the http-server.authentication.oauth2.refresh-tokens.issued-token.timeout value to less than or equal to the duration of the refresh token expiration issued by your IdP. Optimally, the timeout should be slightly less than the refresh token lifespan of your IdP to ensure that sessions end gracefully.