src/libfreeswan/libcrypto/include/hmac_generic.h

   1 #ifndef _HMAC_GENERIC_H
   2 #define _HMAC_GENERIC_H
   3 /*
   4  * HMAC macro helpers
   5  *
   6  * Author: JuanJo Ciarlante <jjo-ipsec@mendoza.gov.ar>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the
  10  * Free Software Foundation; either version 2 of the License, or (at your
  11  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16  * for more details.
  17  *
  18  */
  19
  20 #ifndef DIVUP
  21 #define DIVUP(x,y) ((x + y -1) / y) /* divide, rounding upwards */
  22 #endif
  23 #ifndef HMAC_IPAD
  24 #define         HMAC_IPAD       0x36
  25 #define         HMAC_OPAD       0x5C
  26 #endif
  27 #define HMAC_SET_KEY_IMPL(func_name, hctx_t, blocksize, func_init, func_update) \
  28 void func_name(hctx_t *hctx, const u_int8_t * key, int keylen) { \
  29         int i;\
  30         u_int8_t kb[blocksize];         \
  31         for (i = 0; i < DIVUP(keylen*8, 8); i++) {      \
  32                 kb[i] = key[i] ^ HMAC_IPAD;     \
  33         }                                       \
  34         for (; i < blocksize; i++) {            \
  35                 kb[i] = HMAC_IPAD;              \
  36         }                                       \
  37         func_init(&hctx->ictx);                 \
  38         func_update(&hctx->ictx, kb, blocksize);        \
  39         for (i = 0; i < blocksize; i++) {       \
  40                 kb[i] ^= (HMAC_IPAD ^ HMAC_OPAD);       \
  41         }                                       \
  42         func_init(&hctx->octx);                 \
  43         func_update(&hctx->octx, kb, blocksize);        \
  44 }
  45 #define HMAC_HASH_IMPL(func_name, hctx_t, ctx_t, ahlen, func_update, func_result ) \
  46 void func_name(hctx_t *hctx, const u_int8_t * dat, int len, u_int8_t * hash, int hashlen) {     \
  47         ctx_t ctx;      \
  48         ctx=hctx->ictx; \
  49         if (dat) func_update(&ctx, dat, len);   \
  50         if (hash) {                             \
  51                 u_int8_t hash_buf[ahlen];                       \
  52                 func_result(&ctx, hash_buf, ahlen);     \
  53                 ctx=hctx->octx;                         \
  54                 func_update(&ctx, hash_buf, ahlen);     \
  55                 func_result(&ctx, hash, hashlen);       \
  56                 memset(&ctx, 0, sizeof (ctx));          \
  57                 memset(&hash_buf, 0, sizeof (hash_buf));\
  58         }                                       \
  59 }
  60 #endif /* _HMAC_GENERIC_H */