text: /* rabbit.c
   *
   * Copyright (C) 2006-2016 wolfSSL Inc.
   *
   * This file is part of wolfSSL.
   *
   * wolfSSL is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * wolfSSL is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
   */
  
  
  #ifdef HAVE_CONFIG_H
      #include <config.h>
  #endif
  
  #include <wolfssl/wolfcrypt/settings.h>
  
  #ifndef NO_RABBIT
  
  #include <wolfssl/wolfcrypt/rabbit.h>
  #include <wolfssl/wolfcrypt/error-crypt.h>
  #include <wolfssl/wolfcrypt/logging.h>
  #ifdef NO_INLINE
      #include <wolfssl/wolfcrypt/misc.h>
  #else
      #define WOLFSSL_MISC_INCLUDED
      #include <wolfcrypt/src/misc.c>
  #endif
  
  
  #ifdef BIG_ENDIAN_ORDER
      #define LITTLE32(x) ByteReverseWord32(x)
  #else
      #define LITTLE32(x) (x)
  #endif
  
  #define U32V(x) ((word32)(x) & 0xFFFFFFFFU)
  
  
  /* Square a 32-bit unsigned integer to obtain the 64-bit result and return */
  /* the upper 32 bits XOR the lower 32 bits */
  static word32 RABBIT_g_func(word32 x)
  {
      /* Temporary variables */
      word32 a, b, h, l;
  
      /* Construct high and low argument for squaring */
      a = x&0xFFFF;
      b = x>>16;
  
      /* Calculate high and low result of squaring */
      h = (((U32V(a*a)>>17) + U32V(a*b))>>15) + b*b;
      l = x*x;
  
      /* Return high XOR low */
      return U32V(h^l);
  }
  
  
  /* Calculate the next internal state */
  static void RABBIT_next_state(RabbitCtx* ctx)
  {
      /* Temporary variables */
      word32 g[8], c_old[8], i;
  
      /* Save old counter values */
      for (i=0; i<8; i++)
          c_old[i] = ctx->c[i];
  
      /* Calculate new counter values */
      ctx->c[0] = U32V(ctx->c[0] + 0x4D34D34D + ctx->carry);
      ctx->c[1] = U32V(ctx->c[1] + 0xD34D34D3 + (ctx->c[0] < c_old[0]));
      ctx->c[2] = U32V(ctx->c[2] + 0x34D34D34 + (ctx->c[1] < c_old[1]));
      ctx->c[3] = U32V(ctx->c[3] + 0x4D34D34D + (ctx->c[2] < c_old[2]));
      ctx->c[4] = U32V(ctx->c[4] + 0xD34D34D3 + (ctx->c[3] < c_old[3]));
      ctx->c[5] = U32V(ctx->c[5] + 0x34D34D34 + (ctx->c[4] < c_old[4]));
      ctx->c[6] = U32V(ctx->c[6] + 0x4D34D34D + (ctx->c[5] < c_old[5]));
      ctx->c[7] = U32V(ctx->c[7] + 0xD34D34D3 + (ctx->c[6] < c_old[6]));
      ctx->carry = (ctx->c[7] < c_old[7]);
  
      /* Calculate the g-values */
      for (i=0;i<8;i++)
          g[i] = RABBIT_g_func(U32V(ctx->x[i] + ctx->c[i]));
  
      /* Calculate new state values */
      ctx->x[0] = U32V(g[0] + rotlFixed(g[7],16) + rotlFixed(g[6], 16));
      ctx->x[1] = U32V(g[1] + rotlFixed(g[0], 8) + g[7]);
      ctx->x[2] = U32V(g[2] + rotlFixed(g[1],16) + rotlFixed(g[0], 16));
      ctx->x[3] = U32V(g[3] + rotlFixed(g[2], 8) + g[1]);
      ctx->x[4] = U32V(g[4] + rotlFixed(g[3],16) + rotlFixed(g[2], 16));
      ctx->x[5] = U32V(g[5] + rotlFixed(g[4], 8) + g[3]);
      ctx->x[6] = U32V(g[6] + rotlFixed(g[5],16) + rotlFixed(g[4], 16));
      ctx->x[7] = U32V(g[7] + rotlFixed(g[6], 8) + g[5]);
  }
  
  
  /* IV setup */
  static void wc_RabbitSetIV(Rabbit* ctx, const byte* inIv)
  {
      /* Temporary variables */
      word32 i0, i1, i2, i3, i;
      word32 iv[2];
  
      if (inIv)
          XMEMCPY(iv, inIv, sizeof(iv));
      else
          XMEMSET(iv,    0, sizeof(iv));
  
      /* Generate four subvectors */
      i0 = LITTLE32(iv[0]);
      i2 = LITTLE32(iv[1]);
      i1 = (i0>>16) | (i2&0xFFFF0000);
      i3 = (i2<<16) | (i0&0x0000FFFF);
  
      /* Modify counter values */
      ctx->workCtx.c[0] = ctx->masterCtx.c[0] ^ i0;
      ctx->workCtx.c[1] = ctx->masterCtx.c[1] ^ i1;
      ctx->workCtx.c[2] = ctx->masterCtx.c[2] ^ i2;
      ctx->workCtx.c[3] = ctx->masterCtx.c[3] ^ i3;
      ctx->workCtx.c[4] = ctx->masterCtx.c[4] ^ i0;
      ctx->workCtx.c[5] = ctx->masterCtx.c[5] ^ i1;
      ctx->workCtx.c[6] = ctx->masterCtx.c[6] ^ i2;
      ctx->workCtx.c[7] = ctx->masterCtx.c[7] ^ i3;
  
      /* Copy state variables */
      for (i=0; i<8; i++)
          ctx->workCtx.x[i] = ctx->masterCtx.x[i];
      ctx->workCtx.carry = ctx->masterCtx.carry;
  
      /* Iterate the system four times */
      for (i=0; i<4; i++)
          RABBIT_next_state(&(ctx->workCtx));
  }
  
  
  /* Key setup */
  static INLINE int DoKey(Rabbit* ctx, const byte* key, const byte* iv)
  {
      /* Temporary variables */
      word32 k0, k1, k2, k3, i;
  
      /* Generate four subkeys */
      k0 = LITTLE32(*(word32*)(key+ 0));
      k1 = LITTLE32(*(word32*)(key+ 4));
      k2 = LITTLE32(*(word32*)(key+ 8));
      k3 = LITTLE32(*(word32*)(key+12));
  
      /* Generate initial state variables */
      ctx->masterCtx.x[0] = k0;
      ctx->masterCtx.x[2] = k1;
      ctx->masterCtx.x[4] = k2;
      ctx->masterCtx.x[6] = k3;
      ctx->masterCtx.x[1] = U32V(k3<<16) | (k2>>16);
      ctx->masterCtx.x[3] = U32V(k0<<16) | (k3>>16);
      ctx->masterCtx.x[5] = U32V(k1<<16) | (k0>>16);
      ctx->masterCtx.x[7] = U32V(k2<<16) | (k1>>16);
  
      /* Generate initial counter values */
      ctx->masterCtx.c[0] = rotlFixed(k2, 16);
      ctx->masterCtx.c[2] = rotlFixed(k3, 16);
      ctx->masterCtx.c[4] = rotlFixed(k0, 16);
      ctx->masterCtx.c[6] = rotlFixed(k1, 16);
      ctx->masterCtx.c[1] = (k0&0xFFFF0000) | (k1&0xFFFF);
      ctx->masterCtx.c[3] = (k1&0xFFFF0000) | (k2&0xFFFF);
      ctx->masterCtx.c[5] = (k2&0xFFFF0000) | (k3&0xFFFF);
      ctx->masterCtx.c[7] = (k3&0xFFFF0000) | (k0&0xFFFF);
  
      /* Clear carry bit */
      ctx->masterCtx.carry = 0;
  
      /* Iterate the system four times */
      for (i=0; i<4; i++)
          RABBIT_next_state(&(ctx->masterCtx));
  
      /* Modify the counters */
      for (i=0; i<8; i++)
          ctx->masterCtx.c[i] ^= ctx->masterCtx.x[(i+4)&0x7];
  
      /* Copy master instance to work instance */
      for (i=0; i<8; i++) {
          ctx->workCtx.x[i] = ctx->masterCtx.x[i];
          ctx->workCtx.c[i] = ctx->masterCtx.c[i];
      }
      ctx->workCtx.carry = ctx->masterCtx.carry;
  
      wc_RabbitSetIV(ctx, iv);
  
      return 0;
  }
  
  
  int wc_Rabbit_SetHeap(Rabbit* ctx, void* heap)
  {
      if (ctx == NULL) {
          return BAD_FUNC_ARG;
      }
  
  #ifdef XSTREAM_ALIGN
      ctx->heap = heap;
  #endif
  
      (void)heap;
      return 0;
  }
  
  
  /* Key setup */
  int wc_RabbitSetKey(Rabbit* ctx, const byte* key, const byte* iv)
  {
      if (ctx == NULL || key == NULL) {
          return BAD_FUNC_ARG;
      }
  
  #ifdef XSTREAM_ALIGN
      /* default heap to NULL or heap test value */
      #ifdef WOLFSSL_HEAP_TEST
          ctx->heap = (void*)WOLFSSL_HEAP_TEST;
      #else
          ctx->heap = NULL;
      #endif /* WOLFSSL_HEAP_TEST */
  
      if ((wolfssl_word)key % 4) {
          int alignKey[4];
  
          /* iv aligned in SetIV */
          WOLFSSL_MSG("wc_RabbitSetKey unaligned key");
  
          XMEMCPY(alignKey, key, sizeof(alignKey));
  
          return DoKey(ctx, (const byte*)alignKey, iv);
      }
  #endif /* XSTREAM_ALIGN */
  
      return DoKey(ctx, key, iv);
  }
  
  
  /* Encrypt/decrypt a message of any size */
  static INLINE int DoProcess(Rabbit* ctx, byte* output, const byte* input,
                              word32 msglen)
  {
      /* Encrypt/decrypt all full blocks */
      while (msglen >= 16) {
          /* Iterate the system */
          RABBIT_next_state(&(ctx->workCtx));
  
          /* Encrypt/decrypt 16 bytes of data */
          *(word32*)(output+ 0) = *(word32*)(input+ 0) ^
                     LITTLE32(ctx->workCtx.x[0] ^ (ctx->workCtx.x[5]>>16) ^
                     U32V(ctx->workCtx.x[3]<<16));
          *(word32*)(output+ 4) = *(word32*)(input+ 4) ^
                     LITTLE32(ctx->workCtx.x[2] ^ (ctx->workCtx.x[7]>>16) ^
                     U32V(ctx->workCtx.x[5]<<16));
          *(word32*)(output+ 8) = *(word32*)(input+ 8) ^
                     LITTLE32(ctx->workCtx.x[4] ^ (ctx->workCtx.x[1]>>16) ^
                     U32V(ctx->workCtx.x[7]<<16));
          *(word32*)(output+12) = *(word32*)(input+12) ^
                     LITTLE32(ctx->workCtx.x[6] ^ (ctx->workCtx.x[3]>>16) ^
                     U32V(ctx->workCtx.x[1]<<16));
  
          /* Increment pointers and decrement length */
          input  += 16;
          output += 16;
          msglen -= 16;
      }
  
      /* Encrypt/decrypt remaining data */
      if (msglen) {
  
          word32 i;
          word32 tmp[4];
          byte*  buffer = (byte*)tmp;
  
          XMEMSET(tmp, 0, sizeof(tmp));   /* help static analysis */
  
          /* Iterate the system */
          RABBIT_next_state(&(ctx->workCtx));
  
          /* Generate 16 bytes of pseudo-random data */
          tmp[0] = LITTLE32(ctx->workCtx.x[0] ^
                    (ctx->workCtx.x[5]>>16) ^ U32V(ctx->workCtx.x[3]<<16));
          tmp[1] = LITTLE32(ctx->workCtx.x[2] ^
                    (ctx->workCtx.x[7]>>16) ^ U32V(ctx->workCtx.x[5]<<16));
          tmp[2] = LITTLE32(ctx->workCtx.x[4] ^
                    (ctx->workCtx.x[1]>>16) ^ U32V(ctx->workCtx.x[7]<<16));
          tmp[3] = LITTLE32(ctx->workCtx.x[6] ^
                    (ctx->workCtx.x[3]>>16) ^ U32V(ctx->workCtx.x[1]<<16));
  
          /* Encrypt/decrypt the data */
          for (i=0; i<msglen; i++)
              output[i] = input[i] ^ buffer[i];
      }
  
      return 0;
  }
  
  
  /* Encrypt/decrypt a message of any size */
  int wc_RabbitProcess(Rabbit* ctx, byte* output, const byte* input, word32 msglen)
  {
      if (ctx == NULL || output == NULL || input == NULL) {
          return BAD_FUNC_ARG;
      }
  
  #ifdef XSTREAM_ALIGN
      if ((wolfssl_word)input % 4 || (wolfssl_word)output % 4) {
          #ifndef NO_WOLFSSL_ALLOC_ALIGN
              byte* tmp;
              WOLFSSL_MSG("wc_RabbitProcess unaligned");
  
              tmp = (byte*)XMALLOC(msglen, ctx->heap, DYNAMIC_TYPE_TMP_BUFFER);
              if (tmp == NULL) return MEMORY_E;
  
              XMEMCPY(tmp, input, msglen);
              DoProcess(ctx, tmp, tmp, msglen);
              XMEMCPY(output, tmp, msglen);
  
              XFREE(tmp, ctx->heap, DYNAMIC_TYPE_TMP_BUFFER);
  
              return 0;
          #else
              return BAD_ALIGN_E;
          #endif
      }
  #endif /* XSTREAM_ALIGN */
  
      return DoProcess(ctx, output, input, msglen);
  }
  
  
  #endif /* NO_RABBIT */
  