aesfix - Man Page

Locates 128-bit and 256-bit AES keys in a captured memory image.




SCHEDULE-FILE The aesfix tool corrects bit errors in an AES key schedule read from the specified hex-encoded file.

This program is limited to AES-128 key schedules, and it can only correct unidirectional 1->0 bit errors.  For the most part it has been optimized for readability rather than performance.

The algorithm has these major steps:

1. Given a key schedule containing bit errors, divide the schedule
  into four 7-bit "slices", each of which should be uniquely
  determined by its first four bits.

2. For increasing number of errors w to the key (round 0) bytes:

   a. List possible "decoded" values that could have suffered w
      or fewer unidirectional errors to form the slice.

   b. Consider all the key schedules generated by combinations of
      these decodings.  If one could have decayed into the key
      schedule that we're trying to repair, output it and stop.


aesfix was written by Nadia Heninger and and J. Alex Halderman.

See Also

aeskeyfind(1), biosmemimage(1), rsakeyfind(1)

Referenced By