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Area

token-exchange

Describe the bug

When exchanging an access token issued by an external provider (e.g. Microsoft configured as OpenID Connect v1.0) and user info check disabled, keycloak is returning error invalid_token because the token doesn't contain claim typ. The
typ claim is optional and some providers (e.g. Microsoft) are not setting it. The regression was introduced with https://github.com/keycloak/keycloak/pull/28866

Suggested change is to validate the typ claim only if it is available and make it required only in KeycloakOIDCIdentityProvider

in OIDCIdentityProvider
```
protected boolean isTokenTypeSupported(JsonWebToken parsedToken)

String type = parsedToken.getType();
if (Objects.isNull(type))

}
```

Version

25.0.6

Regression

[X] The issue is a regression

Expected behavior

Access token can be validated in case it doesn't contain typ claim.

Actual behavior

External tokens that do not contain typ claim and user info check disabled cannot be exchanged to internal because of error invalid_token

How to Reproduce?

Configure as OpenID Connect v1.0 identity provider that doesn't set typ claim (e.g. Microsoft), disable user info check, and try to exchange external to internal token with grant_type = urn:ietf:params:oauth:grant-type:token-exchange and subject_token_type=urn:ietf:params:oauth:token-type:jwt.

Anything else?

No response