Use correct error code in error response in token exchange #31547
Description
Description
We need to change the error response value from INVALID_TOKEN to invalid_request.
Discussion
No response
Motivation
The spec in RFC8693 says “Other error codes may also be used, as appropriate.”, and this may allow the currently used error codes, but since the paragraphs above say MUST be, we need to adapt the error codes in the response.
Perhaps we can use error_description for the old “error code” used by Keycloak.
Details
Currently Keycloak returns INVALID_TOKEN instead of invalid_request, but invalid_request must be used as the value of the error field in the error response.
Current error response with an invalid_subject token
{
"error": "invalid_token",
"error_description": "Invalid token"
}