CyaSSL is an SSL library for devices like mbed.
Dependents: cyassl-client Sync
rabbit.c
00001 /* rabbit.c 00002 * 00003 * Copyright (C) 2006-2009 Sawtooth Consulting Ltd. 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 00023 #ifndef NO_RABBIT 00024 00025 #include "rabbit.h" 00026 #include "misc.c" 00027 00028 00029 #ifdef BIG_ENDIAN_ORDER 00030 #define LITTLE32(x) ByteReverseWord32(x) 00031 #else 00032 #define LITTLE32(x) (x) 00033 #endif 00034 00035 #define U32V(x) (word32)(x) 00036 00037 00038 /* Square a 32-bit unsigned integer to obtain the 64-bit result and return */ 00039 /* the upper 32 bits XOR the lower 32 bits */ 00040 static word32 RABBIT_g_func(word32 x) 00041 { 00042 /* Temporary variables */ 00043 word32 a, b, h, l; 00044 00045 /* Construct high and low argument for squaring */ 00046 a = x&0xFFFF; 00047 b = x>>16; 00048 00049 /* Calculate high and low result of squaring */ 00050 h = (((U32V(a*a)>>17) + U32V(a*b))>>15) + b*b; 00051 l = x*x; 00052 00053 /* Return high XOR low */ 00054 return U32V(h^l); 00055 } 00056 00057 00058 /* Calculate the next internal state */ 00059 static void RABBIT_next_state(RabbitCtx* ctx) 00060 { 00061 /* Temporary variables */ 00062 word32 g[8], c_old[8], i; 00063 00064 /* Save old counter values */ 00065 for (i=0; i<8; i++) 00066 c_old[i] = ctx->c[i]; 00067 00068 /* Calculate new counter values */ 00069 ctx->c[0] = U32V(ctx->c[0] + 0x4D34D34D + ctx->carry); 00070 ctx->c[1] = U32V(ctx->c[1] + 0xD34D34D3 + (ctx->c[0] < c_old[0])); 00071 ctx->c[2] = U32V(ctx->c[2] + 0x34D34D34 + (ctx->c[1] < c_old[1])); 00072 ctx->c[3] = U32V(ctx->c[3] + 0x4D34D34D + (ctx->c[2] < c_old[2])); 00073 ctx->c[4] = U32V(ctx->c[4] + 0xD34D34D3 + (ctx->c[3] < c_old[3])); 00074 ctx->c[5] = U32V(ctx->c[5] + 0x34D34D34 + (ctx->c[4] < c_old[4])); 00075 ctx->c[6] = U32V(ctx->c[6] + 0x4D34D34D + (ctx->c[5] < c_old[5])); 00076 ctx->c[7] = U32V(ctx->c[7] + 0xD34D34D3 + (ctx->c[6] < c_old[6])); 00077 ctx->carry = (ctx->c[7] < c_old[7]); 00078 00079 /* Calculate the g-values */ 00080 for (i=0;i<8;i++) 00081 g[i] = RABBIT_g_func(U32V(ctx->x[i] + ctx->c[i])); 00082 00083 /* Calculate new state values */ 00084 ctx->x[0] = U32V(g[0] + rotlFixed(g[7],16) + rotlFixed(g[6], 16)); 00085 ctx->x[1] = U32V(g[1] + rotlFixed(g[0], 8) + g[7]); 00086 ctx->x[2] = U32V(g[2] + rotlFixed(g[1],16) + rotlFixed(g[0], 16)); 00087 ctx->x[3] = U32V(g[3] + rotlFixed(g[2], 8) + g[1]); 00088 ctx->x[4] = U32V(g[4] + rotlFixed(g[3],16) + rotlFixed(g[2], 16)); 00089 ctx->x[5] = U32V(g[5] + rotlFixed(g[4], 8) + g[3]); 00090 ctx->x[6] = U32V(g[6] + rotlFixed(g[5],16) + rotlFixed(g[4], 16)); 00091 ctx->x[7] = U32V(g[7] + rotlFixed(g[6], 8) + g[5]); 00092 } 00093 00094 00095 /* IV setup */ 00096 static void RabbitSetIV(Rabbit* ctx, const byte* iv) 00097 { 00098 /* Temporary variables */ 00099 word32 i0, i1, i2, i3, i; 00100 00101 /* Generate four subvectors */ 00102 i0 = LITTLE32(*(word32*)(iv+0)); 00103 i2 = LITTLE32(*(word32*)(iv+4)); 00104 i1 = (i0>>16) | (i2&0xFFFF0000); 00105 i3 = (i2<<16) | (i0&0x0000FFFF); 00106 00107 /* Modify counter values */ 00108 ctx->workCtx.c[0] = ctx->masterCtx.c[0] ^ i0; 00109 ctx->workCtx.c[1] = ctx->masterCtx.c[1] ^ i1; 00110 ctx->workCtx.c[2] = ctx->masterCtx.c[2] ^ i2; 00111 ctx->workCtx.c[3] = ctx->masterCtx.c[3] ^ i3; 00112 ctx->workCtx.c[4] = ctx->masterCtx.c[4] ^ i0; 00113 ctx->workCtx.c[5] = ctx->masterCtx.c[5] ^ i1; 00114 ctx->workCtx.c[6] = ctx->masterCtx.c[6] ^ i2; 00115 ctx->workCtx.c[7] = ctx->masterCtx.c[7] ^ i3; 00116 00117 /* Copy state variables */ 00118 for (i=0; i<8; i++) 00119 ctx->workCtx.x[i] = ctx->masterCtx.x[i]; 00120 ctx->workCtx.carry = ctx->masterCtx.carry; 00121 00122 /* Iterate the system four times */ 00123 for (i=0; i<4; i++) 00124 RABBIT_next_state(&(ctx->workCtx)); 00125 } 00126 00127 00128 /* Key setup */ 00129 void RabbitSetKey(Rabbit* ctx, const byte* key, const byte* iv) 00130 { 00131 /* Temporary variables */ 00132 word32 k0, k1, k2, k3, i; 00133 00134 /* Generate four subkeys */ 00135 k0 = LITTLE32(*(word32*)(key+ 0)); 00136 k1 = LITTLE32(*(word32*)(key+ 4)); 00137 k2 = LITTLE32(*(word32*)(key+ 8)); 00138 k3 = LITTLE32(*(word32*)(key+12)); 00139 00140 /* Generate initial state variables */ 00141 ctx->masterCtx.x[0] = k0; 00142 ctx->masterCtx.x[2] = k1; 00143 ctx->masterCtx.x[4] = k2; 00144 ctx->masterCtx.x[6] = k3; 00145 ctx->masterCtx.x[1] = U32V(k3<<16) | (k2>>16); 00146 ctx->masterCtx.x[3] = U32V(k0<<16) | (k3>>16); 00147 ctx->masterCtx.x[5] = U32V(k1<<16) | (k0>>16); 00148 ctx->masterCtx.x[7] = U32V(k2<<16) | (k1>>16); 00149 00150 /* Generate initial counter values */ 00151 ctx->masterCtx.c[0] = rotlFixed(k2, 16); 00152 ctx->masterCtx.c[2] = rotlFixed(k3, 16); 00153 ctx->masterCtx.c[4] = rotlFixed(k0, 16); 00154 ctx->masterCtx.c[6] = rotlFixed(k1, 16); 00155 ctx->masterCtx.c[1] = (k0&0xFFFF0000) | (k1&0xFFFF); 00156 ctx->masterCtx.c[3] = (k1&0xFFFF0000) | (k2&0xFFFF); 00157 ctx->masterCtx.c[5] = (k2&0xFFFF0000) | (k3&0xFFFF); 00158 ctx->masterCtx.c[7] = (k3&0xFFFF0000) | (k0&0xFFFF); 00159 00160 /* Clear carry bit */ 00161 ctx->masterCtx.carry = 0; 00162 00163 /* Iterate the system four times */ 00164 for (i=0; i<4; i++) 00165 RABBIT_next_state(&(ctx->masterCtx)); 00166 00167 /* Modify the counters */ 00168 for (i=0; i<8; i++) 00169 ctx->masterCtx.c[i] ^= ctx->masterCtx.x[(i+4)&0x7]; 00170 00171 /* Copy master instance to work instance */ 00172 for (i=0; i<8; i++) { 00173 ctx->workCtx.x[i] = ctx->masterCtx.x[i]; 00174 ctx->workCtx.c[i] = ctx->masterCtx.c[i]; 00175 } 00176 ctx->workCtx.carry = ctx->masterCtx.carry; 00177 00178 if (iv) RabbitSetIV(ctx, iv); 00179 } 00180 00181 00182 /* Encrypt/decrypt a message of any size */ 00183 void RabbitProcess(Rabbit* ctx, byte* output, const byte* input, word32 msglen) 00184 { 00185 00186 /* Encrypt/decrypt all full blocks */ 00187 while (msglen >= 16) { 00188 /* Iterate the system */ 00189 RABBIT_next_state(&(ctx->workCtx)); 00190 00191 /* Encrypt/decrypt 16 bytes of data */ 00192 *(word32*)(output+ 0) = *(word32*)(input+ 0) ^ 00193 LITTLE32(ctx->workCtx.x[0] ^ (ctx->workCtx.x[5]>>16) ^ 00194 U32V(ctx->workCtx.x[3]<<16)); 00195 *(word32*)(output+ 4) = *(word32*)(input+ 4) ^ 00196 LITTLE32(ctx->workCtx.x[2] ^ (ctx->workCtx.x[7]>>16) ^ 00197 U32V(ctx->workCtx.x[5]<<16)); 00198 *(word32*)(output+ 8) = *(word32*)(input+ 8) ^ 00199 LITTLE32(ctx->workCtx.x[4] ^ (ctx->workCtx.x[1]>>16) ^ 00200 U32V(ctx->workCtx.x[7]<<16)); 00201 *(word32*)(output+12) = *(word32*)(input+12) ^ 00202 LITTLE32(ctx->workCtx.x[6] ^ (ctx->workCtx.x[3]>>16) ^ 00203 U32V(ctx->workCtx.x[1]<<16)); 00204 00205 /* Increment pointers and decrement length */ 00206 input += 16; 00207 output += 16; 00208 msglen -= 16; 00209 } 00210 00211 /* Encrypt/decrypt remaining data */ 00212 if (msglen) { 00213 00214 word32 i; 00215 word32 tmp[4]; 00216 byte* buffer = (byte*)tmp; 00217 00218 /* Iterate the system */ 00219 RABBIT_next_state(&(ctx->workCtx)); 00220 00221 /* Generate 16 bytes of pseudo-random data */ 00222 tmp[0] = LITTLE32(ctx->workCtx.x[0] ^ 00223 (ctx->workCtx.x[5]>>16) ^ U32V(ctx->workCtx.x[3]<<16)); 00224 tmp[1] = LITTLE32(ctx->workCtx.x[2] ^ 00225 (ctx->workCtx.x[7]>>16) ^ U32V(ctx->workCtx.x[5]<<16)); 00226 tmp[2] = LITTLE32(ctx->workCtx.x[4] ^ 00227 (ctx->workCtx.x[1]>>16) ^ U32V(ctx->workCtx.x[7]<<16)); 00228 tmp[3] = LITTLE32(ctx->workCtx.x[6] ^ 00229 (ctx->workCtx.x[3]>>16) ^ U32V(ctx->workCtx.x[1]<<16)); 00230 00231 /* Encrypt/decrypt the data */ 00232 for (i=0; i<msglen; i++) 00233 output[i] = input[i] ^ buffer[i]; 00234 } 00235 } 00236 00237 00238 00239 #endif /* NO_RABBIT */
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