If this function returns false, unknown SRP/PSK identifiers
will be rejected with an unknown_psk_identifier alert as soon
as the non-existence is identified. Otherwise, a false
identifier value will be used and the protocol allowed to
proceed, causing the handshake to eventually fail without
revealing that the username does not exist on this system.
If this function returns false, unknown SRP/PSK identifiers will be rejected with an unknown_psk_identifier alert as soon as the non-existence is identified. Otherwise, a false identifier value will be used and the protocol allowed to proceed, causing the handshake to eventually fail without revealing that the username does not exist on this system.