verify_callback

        # OpenSSL::X509::Store.verify_callback

(from ruby core)
---

The callback for additional certificate verification. It is invoked for
each certificate in the chain and can be used to implement custom
certificate verification conditions.

The callback is invoked with two values, a boolean that indicates if the
pre-verification by OpenSSL has succeeded or not, and the StoreContext
in use.

The callback can use StoreContext#error= to change the error code as
needed. The callback must return either true or false.

NOTE: any exception raised within the callback will be ignored.

See also the man page X509_STORE_CTX_set_verify_cb(3).