test(reset): display_random is accepted and ignored - #211
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Firmware no longer renders the Internal Entropy screen -- internal entropy is seed pre-image material, and a host that supplies ext_entropy and reads that screen once can compute SHA256(shown || ext) and derive the seed. test_reset_device_pin and test_failed_pin asserted the ButtonRequest for that screen, so they failed against the new firmware. Rather than dropping display_random from the request, they keep sending it =True and now assert the NEXT message is PinMatrixRequest -- which is a direct test of the compatibility claim: the field stays decodable on the wire and changes nothing. Verified 6/6 against an emulator built from the paired firmware branch.
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Pairs with firmware BitHighlander/keepkey-firmware#336, which stops rendering the Internal Entropy screen.
Why the firmware changed
Internal entropy is seed pre-image material. A host that supplies
ext_entropyand reads that screen once computesSHA256(shown || ext_entropy)and derives the seed. Note this is unaffected by dice entropy — the displayed value is already post-mix, so dice change nothing about the leak.Why these tests failed
test_reset_device_pinandtest_failed_pinsentdisplay_random=Trueand asserted the resultingButtonRequestbefore the PIN matrix. That screen no longer exists, so both failed — this was the only red job on #336.The fix
Rather than dropping
display_randomfrom the requests, they still send it=Trueand now assert the next message isPinMatrixRequest. That turns a broken assertion into a direct test of the compatibility claim: the field stays decodable on the wire and changes nothing observable.Verification
6/6 in
test_msg_resetdevice.pyagainst an emulator built from the paired firmware branch — includingtest_reset_device_dice, confirming dice entropy and the entropy-screen removal coexist. Firmware side was 14/14 green withpython-integration-testsincluded, and #336 has since merged to alpha.