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- /* rabbit.c
- *
- * Copyright (C) 2006-2011 Sawtooth Consulting Ltd.
- *
- * This file is part of CyaSSL.
- *
- * CyaSSL 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.
- *
- * CyaSSL 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
- #ifndef NO_RABBIT
- #include "rabbit.h"
- #include "misc.c"
- #ifdef BIG_ENDIAN_ORDER
- #define LITTLE32(x) ByteReverseWord32(x)
- #else
- #define LITTLE32(x) (x)
- #endif
- #define U32V(x) (word32)(x)
- /* 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 RabbitSetIV(Rabbit* ctx, const byte* iv)
- {
- /* Temporary variables */
- word32 i0, i1, i2, i3, i;
-
- /* Generate four subvectors */
- i0 = LITTLE32(*(word32*)(iv+0));
- i2 = LITTLE32(*(word32*)(iv+4));
- 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 */
- void RabbitSetKey(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;
- if (iv) RabbitSetIV(ctx, iv);
- }
- /* Encrypt/decrypt a message of any size */
- void RabbitProcess(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;
- /* 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];
- }
- }
- #endif /* NO_RABBIT */
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