bsd/crypto/aes/i386/ReadMe.txt

   1 This directory contains a hybrid AES implementation.  The core AES routines
   2 (the actual encryption, decryption, and key expansion) are in:
   3
   4         AES.s
   5         Data.mk
   6         Data.s
   7         EncryptDecrypt.s
   8         ExpandKeyForDecryption.s
   9         ExpandKeyForEncryption.s
  10         MakeData.c
  11
  12 Although the above files do not explicitly include aes.h, they confirm to
  13 certain things defined in it, notably the aes_rval type and the layout of the
  14 aes_encrypt_ctx and aes_decrypt_ctx structures.  These must be kept
  15 compatibility; the definitions of ContextKey and ContextKeyLength in AES.s must
  16 match the offsets of the key ("ks") and key_length ("inf") members of
  17 aes_encrypt_ctx and aes_decrypt_ctx.  (For some reason, aes_inf is a union that
  18 is written as a 32-bit integer and read as an 8-bit integer.  I do not know
  19 why but have reproduced that behavior in the new implementation.)
  20
  21 aes_modes.c extends the API, most notably by implementing CBC mode using the
  22 basic AES block encryption.  It uses aesopt.h and edefs.h.