lib/libcrypto/libaes/aes.h

   1 // I retain copyright in this code but I encourage its free use provided
   2 // that I don't carry any responsibility for the results. I am especially
   3 // happy to see it used in free and open source software. If you do use
   4 // it I would appreciate an acknowledgement of its origin in the code or
   5 // the product that results and I would also appreciate knowing a little
   6 // about the use to which it is being put. I am grateful to Frank Yellin
   7 // for some ideas that are used in this implementation.
   8 //
   9 // Dr B. R. Gladman <brg@gladman.uk.net> 6th April 2001.
  10 //
  11 // This is an implementation of the AES encryption algorithm (Rijndael)
  12 // designed by Joan Daemen and Vincent Rijmen. This version is designed
  13 // to provide both fixed and dynamic block and key lengths and can also
  14 // run with either big or little endian internal byte order (see aes.h).
  15 // It inputs block and key lengths in bytes with the legal values being
  16 // 16, 24 and 32.
  17
  18 /*
  19  * Modified by Jari Ruusu,  May 1 2001
  20  *  - Fixed some compile warnings, code was ok but gcc warned anyway.
  21  *  - Changed basic types: byte -> unsigned char, word -> u_int32_t
  22  *  - Major name space cleanup: Names visible to outside now begin
  23  *    with "aes_" or "AES_". A lot of stuff moved from aes.h to aes.c
  24  *  - Removed C++ and DLL support as part of name space cleanup.
  25  *  - Eliminated unnecessary recomputation of tables. (actual bug fix)
  26  *  - Merged precomputed constant tables to aes.c file.
  27  *  - Removed data alignment restrictions for portability reasons.
  28  *  - Made block and key lengths accept bit count (128/192/256)
  29  *    as well byte count (16/24/32).
  30  *  - Removed all error checks. This change also eliminated the need
  31  *    to preinitialize the context struct to zero.
  32  *  - Removed some totally unused constants.
  33  */
  34
  35 #ifndef _AES_H
  36 #define _AES_H
  37
  38 #if defined(__linux__) && defined(__KERNEL__)
  39 #  include <linux/types.h>
  40 #else
  41 #  include <sys/types.h>
  42 #endif
  43
  44 // CONFIGURATION OPTIONS (see also aes.c)
  45 //
  46 // Define AES_BLOCK_SIZE to set the cipher block size (16, 24 or 32) or
  47 // leave this undefined for dynamically variable block size (this will
  48 // result in much slower code).
  49 // IMPORTANT NOTE: AES_BLOCK_SIZE is in BYTES (16, 24, 32 or undefined). If
  50 // left undefined a slower version providing variable block length is compiled
  51
  52 #define AES_BLOCK_SIZE  16
  53
  54 // The number of key schedule words for different block and key lengths
  55 // allowing for method of computation which requires the length to be a
  56 // multiple of the key length
  57 //
  58 // Nk =       4   6   8
  59 //        -------------
  60 // Nb = 4 |  60  60  64
  61 //      6 |  96  90  96
  62 //      8 | 120 120 120
  63
  64 #if !defined(AES_BLOCK_SIZE) || (AES_BLOCK_SIZE == 32)
  65 #define AES_KS_LENGTH   120
  66 #define AES_RC_LENGTH    29
  67 #else
  68 #define AES_KS_LENGTH   4 * AES_BLOCK_SIZE
  69 #define AES_RC_LENGTH   (9 * AES_BLOCK_SIZE) / 8 - 8
  70 #endif
  71
  72 typedef struct
  73 {
  74     u_int32_t    aes_Nkey;      // the number of words in the key input block
  75     u_int32_t    aes_Nrnd;      // the number of cipher rounds
  76     u_int32_t    aes_e_key[AES_KS_LENGTH];   // the encryption key schedule
  77     u_int32_t    aes_d_key[AES_KS_LENGTH];   // the decryption key schedule
  78 #if !defined(AES_BLOCK_SIZE)
  79     u_int32_t    aes_Ncol;      // the number of columns in the cipher state
  80 #endif
  81 } aes_context;
  82
  83 // THE CIPHER INTERFACE
  84
  85 #if !defined(AES_BLOCK_SIZE)
  86 extern void aes_set_blk(aes_context *, const int);
  87 #endif
  88 extern void aes_set_key(aes_context *, const unsigned char [], const int, const int);
  89 extern void aes_encrypt(const aes_context *, const unsigned char [], unsigned char []);
  90 extern void aes_decrypt(const aes_context *, const unsigned char [], unsigned char []);
  91
  92 // The block length inputs to aes_set_block and aes_set_key are in numbers
  93 // of bytes or bits.  The calls to subroutines must be made in the above
  94 // order but multiple calls can be made without repeating earlier calls
  95 // if their parameters have not changed.
  96
  97 #endif  // _AES_H