Skip to content

nfc: Fix sector overrun in MFC nested dictionary attack #4048

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 2 commits into from
Closed

nfc: Fix sector overrun in MFC nested dictionary attack #4048

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
5825f78
nfc: Fix sector overrun in MFC nested dictionary attack
GMMan Dec 30, 2024
bb27473
nfc: Move code in case any other phases are timing sensitive
GMMan Dec 30, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 13 additions & 0 deletions lib/nfc/protocols/mf_classic/mf_classic_poller.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1900,6 +1900,19 @@ NfcCommand mf_classic_poller_handler_nested_controller(MfClassicPoller* instance
if((dict_attack_ctx->nested_phase == MfClassicNestedPhaseDictAttack ||
dict_attack_ctx->nested_phase == MfClassicNestedPhaseDictAttackResume) &&
(dict_attack_ctx->nested_target_key < dict_target_key_max)) {
if(dict_attack_ctx->reuse_key_sector == instance->sectors_total) {
// Reset target sector to first sector whose key has not been found
for(dict_attack_ctx->reuse_key_sector = 0;
dict_attack_ctx->reuse_key_sector < instance->sectors_total &&
mf_classic_nested_is_target_key_found(instance, true);
dict_attack_ctx->reuse_key_sector++)
;
// Reset to sane value just in case we happen to have all of the keys
if(dict_attack_ctx->reuse_key_sector == instance->sectors_total) {
dict_attack_ctx->reuse_key_sector = 0;
}
}

bool is_last_iter_for_hard_key =
((!is_weak) && ((dict_attack_ctx->nested_target_key % 8) == 7));
if(initial_dict_attack_iter) {
Expand Down