/* arc4.c

 *

 * Copyright (C) 2006-2023 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_RC4

#include <wolfssl/wolfcrypt/error-crypt.h>

#include <wolfssl/wolfcrypt/arc4.h>

int wc_Arc4SetKey(Arc4* arc4, const byte* key, word32 length)

{

    int ret = 0;

    word32 i;

    word32 keyIndex = 0, stateIndex = 0;

    if (arc4 == NULL || key == NULL || length == 0) {

        return BAD_FUNC_ARG;

    }

#if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_ARC4) && \

        defined(HAVE_CAVIUM) && !defined(HAVE_CAVIUM_V)

    if (arc4->asyncDev.marker == WOLFSSL_ASYNC_MARKER_ARC4) {

        return NitroxArc4SetKey(arc4, key, length);

    }

#endif

    arc4->x = 1;

    arc4->y = 0;

    for (i = 0; i < ARC4_STATE_SIZE; i++)

        arc4->state[i] = (byte)i;

    for (i = 0; i < ARC4_STATE_SIZE; i++) {

        word32 a = arc4->state[i];

        stateIndex += key[keyIndex] + a;

        stateIndex &= 0xFF;

        arc4->state[i] = arc4->state[stateIndex];

        arc4->state[stateIndex] = (byte)a;

        if (++keyIndex >= length)

            keyIndex = 0;

    }

    return ret;

}

static WC_INLINE byte MakeByte(word32* x, word32* y, byte* s)

{

    word32 a = s[*x], b;

    *y = (*y+a) & 0xff;

    b = s[*y];

    s[*x] = (byte)b;

    s[*y] = (byte)a;

    *x = (*x+1) & 0xff;

    return s[(a+b) & 0xff];

}

int wc_Arc4Process(Arc4* arc4, byte* out, const byte* in, word32 length)

{

    int ret = 0;

    word32 x;

    word32 y;

    if (arc4 == NULL || out == NULL || in == NULL) {

        return BAD_FUNC_ARG;

    }

#if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_ARC4) && \

        defined(HAVE_CAVIUM) && !defined(HAVE_CAVIUM_V)

    if (arc4->asyncDev.marker == WOLFSSL_ASYNC_MARKER_ARC4) {

        return NitroxArc4Process(arc4, out, in, length);

    }

#endif

    x = arc4->x;

    y = arc4->y;

    while(length--)

        *out++ = *in++ ^ MakeByte(&x, &y, arc4->state);

    arc4->x = (byte)x;

    arc4->y = (byte)y;

    return ret;

}

/* Initialize Arc4 for use with async device */

int wc_Arc4Init(Arc4* arc4, void* heap, int devId)

{

    int ret = 0;

    if (arc4 == NULL)

        return BAD_FUNC_ARG;

    arc4->heap = heap;

#if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_ARC4)

    ret = wolfAsync_DevCtxInit(&arc4->asyncDev, WOLFSSL_ASYNC_MARKER_ARC4,

        arc4->heap, devId);

#else

    (void)devId;

#endif /* WOLFSSL_ASYNC_CRYPT */

    return ret;

}

/* Free Arc4 from use with async device */

void wc_Arc4Free(Arc4* arc4)

{

    if (arc4 == NULL)

        return;

#if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_ARC4)

    wolfAsync_DevCtxFree(&arc4->asyncDev, WOLFSSL_ASYNC_MARKER_ARC4);

#endif /* WOLFSSL_ASYNC_CRYPT */

}

#endif /* NO_RC4 */