rabbit.c

00001 /* rabbit.c
00002  *
00003  * Copyright (C) 2006-2013 wolfSSL Inc.
00004  *
00005  * This file is part of CyaSSL.
00006  *
00007  * CyaSSL is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 2 of the License, or
00010  * (at your option) any later version.
00011  *
00012  * CyaSSL is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with this program; if not, write to the Free Software
00019  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
00020  */
00021 
00022 #ifdef HAVE_CONFIG_H
00023     #include <config.h>
00024 #endif
00025 
00026 #include <cyassl/ctaocrypt/settings.h>
00027 
00028 #ifndef NO_RABBIT
00029 
00030 #include <cyassl/ctaocrypt/rabbit.h>
00031 #include <cyassl/ctaocrypt/ctaoerror2.h>
00032 #include <cyassl/ctaocrypt/logging.h>
00033 #ifdef NO_INLINE
00034     #include <cyassl/ctaocrypt/misc.h>
00035 #else
00036     #include <ctaocrypt/src/misc.c>
00037 #endif
00038 
00039 
00040 #ifdef BIG_ENDIAN_ORDER
00041     #define LITTLE32(x) ByteReverseWord32(x)
00042 #else
00043     #define LITTLE32(x) (x)
00044 #endif
00045 
00046 #define U32V(x) ((word32)(x) & 0xFFFFFFFFU)
00047 
00048 
00049 /* Square a 32-bit unsigned integer to obtain the 64-bit result and return */
00050 /* the upper 32 bits XOR the lower 32 bits */
00051 static word32 RABBIT_g_func(word32 x)
00052 {
00053     /* Temporary variables */
00054     word32 a, b, h, l;
00055 
00056     /* Construct high and low argument for squaring */
00057     a = x&0xFFFF;
00058     b = x>>16;
00059 
00060     /* Calculate high and low result of squaring */
00061     h = (((U32V(a*a)>>17) + U32V(a*b))>>15) + b*b;
00062     l = x*x;
00063 
00064     /* Return high XOR low */
00065     return U32V(h^l);
00066 }
00067 
00068 
00069 /* Calculate the next internal state */
00070 static void RABBIT_next_state(RabbitCtx* ctx)
00071 {
00072     /* Temporary variables */
00073     word32 g[8], c_old[8], i;
00074 
00075     /* Save old counter values */
00076     for (i=0; i<8; i++)
00077         c_old[i] = ctx->c[i];
00078 
00079     /* Calculate new counter values */
00080     ctx->c[0] = U32V(ctx->c[0] + 0x4D34D34D + ctx->carry);
00081     ctx->c[1] = U32V(ctx->c[1] + 0xD34D34D3 + (ctx->c[0] < c_old[0]));
00082     ctx->c[2] = U32V(ctx->c[2] + 0x34D34D34 + (ctx->c[1] < c_old[1]));
00083     ctx->c[3] = U32V(ctx->c[3] + 0x4D34D34D + (ctx->c[2] < c_old[2]));
00084     ctx->c[4] = U32V(ctx->c[4] + 0xD34D34D3 + (ctx->c[3] < c_old[3]));
00085     ctx->c[5] = U32V(ctx->c[5] + 0x34D34D34 + (ctx->c[4] < c_old[4]));
00086     ctx->c[6] = U32V(ctx->c[6] + 0x4D34D34D + (ctx->c[5] < c_old[5]));
00087     ctx->c[7] = U32V(ctx->c[7] + 0xD34D34D3 + (ctx->c[6] < c_old[6]));
00088     ctx->carry = (ctx->c[7] < c_old[7]);
00089    
00090     /* Calculate the g-values */
00091     for (i=0;i<8;i++)
00092         g[i] = RABBIT_g_func(U32V(ctx->x[i] + ctx->c[i]));
00093 
00094     /* Calculate new state values */
00095     ctx->x[0] = U32V(g[0] + rotlFixed(g[7],16) + rotlFixed(g[6], 16));
00096     ctx->x[1] = U32V(g[1] + rotlFixed(g[0], 8) + g[7]);
00097     ctx->x[2] = U32V(g[2] + rotlFixed(g[1],16) + rotlFixed(g[0], 16));
00098     ctx->x[3] = U32V(g[3] + rotlFixed(g[2], 8) + g[1]);
00099     ctx->x[4] = U32V(g[4] + rotlFixed(g[3],16) + rotlFixed(g[2], 16));
00100     ctx->x[5] = U32V(g[5] + rotlFixed(g[4], 8) + g[3]);
00101     ctx->x[6] = U32V(g[6] + rotlFixed(g[5],16) + rotlFixed(g[4], 16));
00102     ctx->x[7] = U32V(g[7] + rotlFixed(g[6], 8) + g[5]);
00103 }
00104 
00105 
00106 /* IV setup */
00107 static void RabbitSetIV(Rabbit* ctx, const byte* iv)
00108 {
00109     /* Temporary variables */
00110     word32 i0, i1, i2, i3, i;
00111       
00112     /* Generate four subvectors */
00113     i0 = LITTLE32(*(word32*)(iv+0));
00114     i2 = LITTLE32(*(word32*)(iv+4));
00115     i1 = (i0>>16) | (i2&0xFFFF0000);
00116     i3 = (i2<<16) | (i0&0x0000FFFF);
00117 
00118     /* Modify counter values */
00119     ctx->workCtx.c[0] = ctx->masterCtx.c[0] ^ i0;
00120     ctx->workCtx.c[1] = ctx->masterCtx.c[1] ^ i1;
00121     ctx->workCtx.c[2] = ctx->masterCtx.c[2] ^ i2;
00122     ctx->workCtx.c[3] = ctx->masterCtx.c[3] ^ i3;
00123     ctx->workCtx.c[4] = ctx->masterCtx.c[4] ^ i0;
00124     ctx->workCtx.c[5] = ctx->masterCtx.c[5] ^ i1;
00125     ctx->workCtx.c[6] = ctx->masterCtx.c[6] ^ i2;
00126     ctx->workCtx.c[7] = ctx->masterCtx.c[7] ^ i3;
00127 
00128     /* Copy state variables */
00129     for (i=0; i<8; i++)
00130         ctx->workCtx.x[i] = ctx->masterCtx.x[i];
00131     ctx->workCtx.carry = ctx->masterCtx.carry;
00132 
00133     /* Iterate the system four times */
00134     for (i=0; i<4; i++)
00135         RABBIT_next_state(&(ctx->workCtx));
00136 }
00137 
00138 
00139 /* Key setup */
00140 static INLINE int DoKey(Rabbit* ctx, const byte* key, const byte* iv)
00141 {
00142     /* Temporary variables */
00143     word32 k0, k1, k2, k3, i;
00144 
00145     /* Generate four subkeys */
00146     k0 = LITTLE32(*(word32*)(key+ 0));
00147     k1 = LITTLE32(*(word32*)(key+ 4));
00148     k2 = LITTLE32(*(word32*)(key+ 8));
00149     k3 = LITTLE32(*(word32*)(key+12));
00150 
00151     /* Generate initial state variables */
00152     ctx->masterCtx.x[0] = k0;
00153     ctx->masterCtx.x[2] = k1;
00154     ctx->masterCtx.x[4] = k2;
00155     ctx->masterCtx.x[6] = k3;
00156     ctx->masterCtx.x[1] = U32V(k3<<16) | (k2>>16);
00157     ctx->masterCtx.x[3] = U32V(k0<<16) | (k3>>16);
00158     ctx->masterCtx.x[5] = U32V(k1<<16) | (k0>>16);
00159     ctx->masterCtx.x[7] = U32V(k2<<16) | (k1>>16);
00160 
00161     /* Generate initial counter values */
00162     ctx->masterCtx.c[0] = rotlFixed(k2, 16);
00163     ctx->masterCtx.c[2] = rotlFixed(k3, 16);
00164     ctx->masterCtx.c[4] = rotlFixed(k0, 16);
00165     ctx->masterCtx.c[6] = rotlFixed(k1, 16);
00166     ctx->masterCtx.c[1] = (k0&0xFFFF0000) | (k1&0xFFFF);
00167     ctx->masterCtx.c[3] = (k1&0xFFFF0000) | (k2&0xFFFF);
00168     ctx->masterCtx.c[5] = (k2&0xFFFF0000) | (k3&0xFFFF);
00169     ctx->masterCtx.c[7] = (k3&0xFFFF0000) | (k0&0xFFFF);
00170 
00171     /* Clear carry bit */
00172     ctx->masterCtx.carry = 0;
00173 
00174     /* Iterate the system four times */
00175     for (i=0; i<4; i++)
00176         RABBIT_next_state(&(ctx->masterCtx));
00177 
00178     /* Modify the counters */
00179     for (i=0; i<8; i++)
00180         ctx->masterCtx.c[i] ^= ctx->masterCtx.x[(i+4)&0x7];
00181 
00182     /* Copy master instance to work instance */
00183     for (i=0; i<8; i++) {
00184         ctx->workCtx.x[i] = ctx->masterCtx.x[i];
00185         ctx->workCtx.c[i] = ctx->masterCtx.c[i];
00186     }
00187     ctx->workCtx.carry = ctx->masterCtx.carry;
00188 
00189     if (iv) RabbitSetIV(ctx, iv);
00190 
00191     return 0;
00192 }
00193 
00194 
00195 /* Key setup */
00196 int RabbitSetKey(Rabbit* ctx, const byte* key, const byte* iv)
00197 {
00198 #ifdef XSTREAM_ALIGN
00199     if ((word)key % 4 || (iv && (word)iv % 4)) {
00200         int alignKey[4];
00201         int alignIv[2];
00202 
00203         CYASSL_MSG("RabbitSetKey unaligned key/iv");
00204 
00205         XMEMCPY(alignKey, key, sizeof(alignKey));
00206         if (iv) {
00207             XMEMCPY(alignIv,  iv,  sizeof(alignIv));
00208             iv = (const byte*)alignIv;
00209         }
00210 
00211         return DoKey(ctx, (const byte*)alignKey, iv);
00212     }
00213 #endif /* XSTREAM_ALIGN */
00214 
00215     return DoKey(ctx, key, iv);
00216 }
00217 
00218 
00219 /* Encrypt/decrypt a message of any size */
00220 static INLINE int DoProcess(Rabbit* ctx, byte* output, const byte* input,
00221                             word32 msglen)
00222 {
00223     /* Encrypt/decrypt all full blocks */
00224     while (msglen >= 16) {
00225         /* Iterate the system */
00226         RABBIT_next_state(&(ctx->workCtx));
00227 
00228         /* Encrypt/decrypt 16 bytes of data */
00229         *(word32*)(output+ 0) = *(word32*)(input+ 0) ^
00230                    LITTLE32(ctx->workCtx.x[0] ^ (ctx->workCtx.x[5]>>16) ^
00231                    U32V(ctx->workCtx.x[3]<<16));
00232         *(word32*)(output+ 4) = *(word32*)(input+ 4) ^
00233                    LITTLE32(ctx->workCtx.x[2] ^ (ctx->workCtx.x[7]>>16) ^
00234                    U32V(ctx->workCtx.x[5]<<16));
00235         *(word32*)(output+ 8) = *(word32*)(input+ 8) ^
00236                    LITTLE32(ctx->workCtx.x[4] ^ (ctx->workCtx.x[1]>>16) ^
00237                    U32V(ctx->workCtx.x[7]<<16));
00238         *(word32*)(output+12) = *(word32*)(input+12) ^
00239                    LITTLE32(ctx->workCtx.x[6] ^ (ctx->workCtx.x[3]>>16) ^
00240                    U32V(ctx->workCtx.x[1]<<16));
00241 
00242         /* Increment pointers and decrement length */
00243         input  += 16;
00244         output += 16;
00245         msglen -= 16;
00246     }
00247 
00248     /* Encrypt/decrypt remaining data */
00249     if (msglen) {
00250 
00251         word32 i;
00252         word32 tmp[4];
00253         byte*  buffer = (byte*)tmp;
00254 
00255         XMEMSET(tmp, 0, sizeof(tmp));   /* help static analysis */
00256 
00257         /* Iterate the system */
00258         RABBIT_next_state(&(ctx->workCtx));
00259 
00260         /* Generate 16 bytes of pseudo-random data */
00261         tmp[0] = LITTLE32(ctx->workCtx.x[0] ^
00262                   (ctx->workCtx.x[5]>>16) ^ U32V(ctx->workCtx.x[3]<<16));
00263         tmp[1] = LITTLE32(ctx->workCtx.x[2] ^ 
00264                   (ctx->workCtx.x[7]>>16) ^ U32V(ctx->workCtx.x[5]<<16));
00265         tmp[2] = LITTLE32(ctx->workCtx.x[4] ^ 
00266                   (ctx->workCtx.x[1]>>16) ^ U32V(ctx->workCtx.x[7]<<16));
00267         tmp[3] = LITTLE32(ctx->workCtx.x[6] ^ 
00268                   (ctx->workCtx.x[3]>>16) ^ U32V(ctx->workCtx.x[1]<<16));
00269 
00270         /* Encrypt/decrypt the data */
00271         for (i=0; i<msglen; i++)
00272             output[i] = input[i] ^ buffer[i];
00273     }
00274 
00275     return 0;
00276 }
00277 
00278 
00279 /* Encrypt/decrypt a message of any size */
00280 int RabbitProcess(Rabbit* ctx, byte* output, const byte* input, word32 msglen)
00281 {
00282 #ifdef XSTREAM_ALIGN
00283     if ((word)input % 4 || (word)output % 4) {
00284         #ifndef NO_CYASSL_ALLOC_ALIGN
00285             byte* tmp;
00286             CYASSL_MSG("RabbitProcess unaligned");
00287 
00288             tmp = (byte*)XMALLOC(msglen, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00289             if (tmp == NULL) return MEMORY_E;
00290 
00291             XMEMCPY(tmp, input, msglen);
00292             DoProcess(ctx, tmp, tmp, msglen);
00293             XMEMCPY(output, tmp, msglen);
00294 
00295             XFREE(tmp, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00296 
00297             return 0;
00298         #else
00299             return BAD_ALIGN_E;
00300         #endif
00301     }
00302 #endif /* XSTREAM_ALIGN */
00303 
00304     return DoProcess(ctx, output, input, msglen);
00305 }
00306 
00307 
00308 #endif /* NO_RABBIT */