I'm analyzing a binary which for its AES encryption, its only calling aeskeygenassist once and for the last argument (imm8, the round) its sending static value of 0x46.

Does this mean its using only one round of AES key derivation? Does this make the crypto implementation vulnerable?

If yes, how? How can we recover the encrypted data? Let's say it's in use in a malicious app and if the code is vulnerable I want to recover encrypted data.

  • $\begingroup$ an implementation does not need aeskeygenassist to create subkeys, it could be using a different method, although I do not know what it is using aeskeygenassist for, as imm8 is the rcon value, and 0x46 is not a valid rcon value $\endgroup$ – Richie Frame Dec 2 '19 at 23:43
  • $\begingroup$ Perhaps it might be a test case? $\endgroup$ – SEJPM Dec 3 '19 at 17:26

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