arc4.c

00001 /* arc4.c
00002  *
00003  * Copyright (C) 2006-2016 wolfSSL Inc.
00004  *
00005  * This file is part of wolfSSL.
00006  *
00007  * wolfSSL 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  * wolfSSL 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
00020  */
00021 
00022 
00023 #ifdef HAVE_CONFIG_H
00024     #include <config.h>
00025 #endif
00026 
00027 #include <wolfssl/wolfcrypt/settings.h>
00028 
00029 #ifndef NO_RC4
00030 
00031 #include <wolfssl/wolfcrypt/error-crypt.h>
00032 #include <wolfssl/wolfcrypt/arc4.h>
00033 
00034 
00035 int wc_Arc4SetKey(Arc4* arc4, const byte* key, word32 length)
00036 {
00037     int ret = 0;
00038     word32 i;
00039     word32 keyIndex = 0, stateIndex = 0;
00040 
00041 #if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_ARC4) && \
00042         defined(HAVE_CAVIUM) && !defined(HAVE_CAVIUM_V)
00043     if (arc4->asyncDev.marker == WOLFSSL_ASYNC_MARKER_ARC4) {
00044         return NitroxArc4SetKey(arc4, key, length);
00045     }
00046 #endif
00047 
00048     arc4->x = 1;
00049     arc4->y = 0;
00050 
00051     for (i = 0; i < ARC4_STATE_SIZE; i++)
00052         arc4->state[i] = (byte)i;
00053 
00054     for (i = 0; i < ARC4_STATE_SIZE; i++) {
00055         word32 a = arc4->state[i];
00056         stateIndex += key[keyIndex] + a;
00057         stateIndex &= 0xFF;
00058         arc4->state[i] = arc4->state[stateIndex];
00059         arc4->state[stateIndex] = (byte)a;
00060 
00061         if (++keyIndex >= length)
00062             keyIndex = 0;
00063     }
00064 
00065     return ret;
00066 }
00067 
00068 
00069 static INLINE byte MakeByte(word32* x, word32* y, byte* s)
00070 {
00071     word32 a = s[*x], b;
00072     *y = (*y+a) & 0xff;
00073 
00074     b = s[*y];
00075     s[*x] = (byte)b;
00076     s[*y] = (byte)a;
00077     *x = (*x+1) & 0xff;
00078 
00079     return s[(a+b) & 0xff];
00080 }
00081 
00082 
00083 int wc_Arc4Process(Arc4* arc4, byte* out, const byte* in, word32 length)
00084 {
00085     int ret = 0;
00086     word32 x;
00087     word32 y;
00088 
00089 #if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_ARC4) && \
00090         defined(HAVE_CAVIUM) && !defined(HAVE_CAVIUM_V)
00091     if (arc4->asyncDev.marker == WOLFSSL_ASYNC_MARKER_ARC4) {
00092         return NitroxArc4Process(arc4, out, in, length);
00093     }
00094 #endif
00095 
00096     x = arc4->x;
00097     y = arc4->y;
00098 
00099     while(length--)
00100         *out++ = *in++ ^ MakeByte(&x, &y, arc4->state);
00101 
00102     arc4->x = (byte)x;
00103     arc4->y = (byte)y;
00104 
00105     return ret;
00106 }
00107 
00108 /* Initialize Arc4 for use with async device */
00109 int wc_Arc4Init(Arc4* arc4, void* heap, int devId)
00110 {
00111     int ret = 0;
00112 
00113     if (arc4 == NULL)
00114         return BAD_FUNC_ARG;
00115 
00116     arc4->heap = heap;
00117 
00118 #if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_ARC4)
00119     ret = wolfAsync_DevCtxInit(&arc4->asyncDev, WOLFSSL_ASYNC_MARKER_ARC4,
00120         arc4->heap, devId);
00121 #else
00122     (void)devId;
00123 #endif /* WOLFSSL_ASYNC_CRYPT */
00124 
00125     return ret;
00126 }
00127 
00128 
00129 /* Free Arc4 from use with async device */
00130 void wc_Arc4Free(Arc4* arc4)
00131 {
00132     if (arc4 == NULL)
00133         return;
00134 
00135 #if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_ARC4)
00136     wolfAsync_DevCtxFree(&arc4->asyncDev, WOLFSSL_ASYNC_MARKER_ARC4);
00137 #endif /* WOLFSSL_ASYNC_CRYPT */
00138 }
00139 
00140 #endif /* NO_RC4 */
00141 
00142