Bluetooth: host: Mark the option BT_FIXED_PASSKEY as insecure

Mark the option BT_FIXED_PASSKEY as an insecure option.
During Legacy pairing the passkey is used as encryption key, and
brute-forcing this is easy.
During LE Secure Connections the passkey is checked one bit at a time,
so when it is fixed the passkey can be deduced with series of pairing
attempts.

Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>
2 files changed