Confidential access type is for server-side clients that need to perform a browser login and require a client secret when they turn an access code into an access token,
(see https://tools.ietf.org/html/rfc6749#section-4.1.3[Access Token Request] in the OAuth 2.0 spec for more details). This type should be used for server-side applications.
Public access type is for client-side clients that need to perform a browser login. With a client-side application there is no way to keep a secret safe. Instead it is very important to restrict access by configuring correct redirect URIs for the client.
Mutual TLS binds an access token and a refresh token with a client certificate exchanged during TLS handshake. This prevents an attacker who finds a way to steal these tokens from exercising the tokens. The type of token is called a holder-of-key token. Unlike bearer tokens, the recipient of a holder-of-key token can verify whether the sender of the token is legitimate.
If the following conditions are satisfied on a token request, {project_name} will bind an access token and a refresh token with a client certificate and issue them as holder-of-key tokens. If all conditions are not met, {project_name} rejects the token request.
* A token request is sent to the token endpoint in an authorization code flow or a hybrid flow
* On TLS handshake, {project_name} requests a client certificate and a client send its client certificate
* On TLS handshake, {project_name} successfully verifies the client certificate
To enable mutual TLS in {project_name}, see <<_enable-mtls-wildfly, Enable mutual SSL in WildFly>>.
In the following cases, {project_name} will verify the client sending the access token or the refresh token; if verification fails, {project_name} rejects the token.
* A token refresh request is sent to the token endpoint with a holder-of-key refresh token
* A UserInfo request is sent to UserInfo endpoint with a holder-of-key access token
* A logout request is sent to Logout endpoint with a holder-of-key refresh token
Please see https://tools.ietf.org/html/draft-ietf-oauth-mtls-08#section-3[Mutual TLS Client Certificate Bound Access Tokens] in the OAuth 2.0 Mutual TLS Client Authentication and Certificate Bound Access Tokens for more details.
WARNING:
None of the keycloak client adapters currently support holder-of-key token verification.
Instead, keycloak adapters currently treat access and refresh tokens as bearer tokens.