include/aes.h

   1 /*
   2  * Copyright (c) 2011 The Chromium OS Authors.
   3  * (C) Copyright 2010 - 2011 NVIDIA Corporation <www.nvidia.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #ifndef _AES_REF_H_
   9 #define _AES_REF_H_
  10
  11 /*
  12  * AES encryption library, with small code size, supporting only 128-bit AES
  13  *
  14  * AES is a stream cipher which works a block at a time, with each block
  15  * in this case being AES_KEY_LENGTH bytes.
  16  */
  17
  18 enum {
  19         AES_STATECOLS   = 4,    /* columns in the state & expanded key */
  20         AES_KEYCOLS     = 4,    /* columns in a key */
  21         AES_ROUNDS      = 10,   /* rounds in encryption */
  22
  23         AES_KEY_LENGTH  = 128 / 8,
  24         AES_EXPAND_KEY_LENGTH   = 4 * AES_STATECOLS * (AES_ROUNDS + 1),
  25 };
  26
  27 /**
  28  * Expand a key into a key schedule, which is then used for the other
  29  * operations.
  30  *
  31  * \param key           Key, of length AES_KEY_LENGTH bytes
  32  * \param expkey        Buffer to place expanded key, AES_EXPAND_KEY_LENGTH
  33  */
  34 void aes_expand_key(u8 *key, u8 *expkey);
  35
  36 /**
  37  * Encrypt a single block of data
  38  *
  39  * in           Input data
  40  * expkey       Expanded key to use for encryption (from aes_expand_key())
  41  * out          Output data
  42  */
  43 void aes_encrypt(u8 *in, u8 *expkey, u8 *out);
  44
  45 /**
  46  * Decrypt a single block of data
  47  *
  48  * in           Input data
  49  * expkey       Expanded key to use for decryption (from aes_expand_key())
  50  * out          Output data
  51  */
  52 void aes_decrypt(u8 *in, u8 *expkey, u8 *out);
  53
  54 #endif /* _AES_REF_H_ */