[keycloak-user] Verifying a password

My mobile app is connected to the server using bearer-only tokens. The tokens were obtained using username/password. A particular screen in the app requires the user to re-enter the password, so that the password can be verified at the server-side. Is there an elegant REST or Java API to perform a simple password verification, besides a call to /protocol/openid-connect/token endpoint, which brings all the tokens?