Cordea

In the OAuth library for nim prior to version 0.11, the Authorization Code grant and Implicit grant both rely on the `state` parameter to prevent cross-site request forgery (CSRF) attacks where a resource owner might have their session associated with protected resources belonging to an attacker. When this project is compiled with certain compiler flags set, it is possible that the `state` parameter will not be checked at all, creating a CSRF vulnerability. Version 0.11 checks the `state` parameter using a regular `if` statement or `doAssert` instead of relying on a plain `assert`. `doAssert` will achieve the desired behavior even if `-d:danger` or `--assertions:off` is set.

In the OAuth library for nim prior to version 0.11, the `state` values generated by the `generateState` function do not have sufficient entropy. These can be successfully guessed by an attacker allowing them to perform a CSRF vs a user, associating the user's session with the attacker's protected resources. While `state` isn't exactly a cryptographic value, it should be generated in a cryptographically secure way. `generateState` should be using a CSPRNG. Version 0.11 modifies the `generateState` function to generate `state` values of at least 128 bits of entropy while using a CSPRNG.