shacal1_enc.c

   1 /**
   2  * \file        shacal1_enc.c
   3  * \author      Daniel Otte
   4  * \date        2008-05-06
   5  * \par License:
   6  * GPL
   7  * \brief SHACAL1 encryption only implementation.
   8  *
   9  */
  10
  11 #include <stdint.h>
  12 #include <string.h>
  13 #include "sha1.h"
  14 #include "shacal1_enc.h"
  15
  16 void shacal1_enc(void* buffer, void* key, uint16_t keysize_b){
  17         sha1_ctx_t ctx, t_ctx;
  18         uint8_t i;
  19         memcpy(t_ctx.h, buffer, SHA1_HASH_BITS/8);
  20
  21         uint8_t keybuffer[SHA1_BLOCK_BITS/8];
  22         memset(keybuffer, 0, SHA1_BLOCK_BITS/8);
  23         if(keysize_b>SHA1_BLOCK_BITS)
  24                 keysize_b=SHA1_BLOCK_BITS;
  25         memcpy(keybuffer, key, (keysize_b+7)/8);
  26
  27         memcpy(t_ctx.h, buffer, SHA1_HASH_BITS/8);
  28         sha1_ctx2hash((sha1_hash_t*)(&(ctx.h[0])), &t_ctx);
  29         memcpy(t_ctx.h, ctx.h, SHA1_HASH_BITS/8);
  30         sha1_nextBlock(&ctx, keybuffer);
  31         for(i=0; i<5; ++i)
  32                 ctx.h[i] -= t_ctx.h[i];
  33         sha1_ctx2hash(buffer, &ctx);
  34 }
  35
  36