memory locations in code are now accurate and the CC output is not
corrupted by the config's crc.
also the looping and flags for what to read are now correctly
implemented in the code.
This implements the attack described in
Carlo Meijer, Roel Verdult, "Ciphertext-only Cryptanalysis on Hardened
Mifare Classic Cards" in Proceedings of the 22nd ACM SIGSAC Conference on
Computer and Communications Security, 2015
It uses precomputed tables for many bitflip properties (not only two as in the paper)
and is therefore quite efficient. To prevent failing it doesn't do
differential analysis with several nonce bytes' Sum(a8) properties (each of them
may be wrongly guessed) - instead it concentrates on one nonce byte and tries all
Sum(a8) property guesses sequentially (ordered by probability). The brute force phase
makes use of aczid's bit sliced brute forcer (https://github.com/aczid/crypto1_bs).
Includes runtime CPU-detection to leverage modern (and old) SIMD instructions
with a single executable.
add parameter for # bits to read
auto get samples after lf read/snoop (don't need to do a `data samples`
anymore)
add safe function to get DemodBuffer
add some lf demod comments and apply new lf_read function instead of
read then get samples.
fixed output bug in lf t55xx config print
fixed small bug in lf t55xx detect during ST check
fix noralsy demod bug (st should be true)
fix sprint_bin_break bug (didn't print last bit)
add a function to save/restore demodbuffer
remove redundant countFC call in PSKDemod
clean up pskclockdetect functions
fix indala26decode bug (end of data sometimes not correct)
improve PSK detection / demodulation
improve NRZ detection
improve t55xx commands & fix a few bugs
add t55xx page1 detection - added it to lf search
added experimental t55xx testmode write
helps get the data dumped even if positioning isn't 100% perfect.
also switched em4x05 commands to WaitUS instead of SpinDelayUs, per
@pwpiwi 's suggestion.
- correctly using stdtypes.h printf and scanf format string macros (PRIx64 et al)
- coverity fixes to client/cmdhfmf.c
- fix linker warning re missing entry point when linking fullimage.elf
plus some minor adjustments
and added a quick em4x05 test:
bool EM4x05Block0Test(uint32_t *wordData)
if successful very likely the tag is an em4x05 or compatible...
@iceman1001 s updates + some of my own.
still more to do:
-auto demod responses
-figure out config block
-figure out block 0 info / serial # in block 1
-figure out block 3 protection data
-add dump all blocks cmd
- Don't increment the nonce when random mode is disabled (this breaks the
standard attack).
- Don't attempt the standard attack when random mode is enabled (there's no
point as it won't work, per comments from @pwpiwi).
- Attempt the moebius attack if the standard attack fails.
This makes the PM3 generate pseudo-random nonces rather than sequential
nonces, to make it act a bit more like a "real" MFC card. A reader would
otherwise be able to detect the PM3 probing based on the predictable nonces
and throw different authentication challenges (or refuse to authenticate at
all).
The code includes an implementation of a rand-like function (prand), similar
to the one from libc, which is seeded automatically based on the time it
takes between the PM3 starting up and the first call to the RNG.
This isn't cryptographically random, but should be "good enough" to be able
to evade basic detection.
