/* sha.c
 *
 * Copyright (C) 2006-2015 wolfSSL Inc.
 *
 * This file is part of wolfSSL. (formerly known as CyaSSL)
 *
 * 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 02110-1301, USA
 */


#ifdef HAVE_CONFIG_H
    #include <config.h>
#endif

#include <wolfssl/wolfcrypt/settings.h>

#if !defined(NO_SHA)

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

#ifdef NO_INLINE
    #include <wolfssl/wolfcrypt/misc.h>
#else
    #include <wolfcrypt/src/misc.c>
#endif

/* fips wrapper calls, user can call direct */
#ifdef HAVE_FIPS
	int wc_InitSha(Sha* sha)
	{
	    return InitSha_fips(sha);
	}


	int wc_ShaUpdate(Sha* sha, const byte* data, word32 len)
	{
	    return ShaUpdate_fips(sha, data, len);
	}


	int wc_ShaFinal(Sha* sha, byte* out)
	{
	    return ShaFinal_fips(sha,out);
    }

    int wc_ShaHash(const byte* data, word32 sz, byte* out)
    {
        return ShaHash(data, sz, out);
    }

#else /* else build without fips */

#ifdef WOLFSSL_PIC32MZ_HASH
#define wc_InitSha   wc_InitSha_sw
#define wc_ShaUpdate wc_ShaUpdate_sw
#define wc_ShaFinal  wc_ShaFinal_sw
#endif


#ifdef FREESCALE_MMCAU
    #include "cau_api.h"
    #define XTRANSFORM(S,B)  cau_sha1_hash_n((B), 1, ((S))->digest)
#else
    #define XTRANSFORM(S,B)  Transform((S))
#endif

#ifdef STM32F2_HASH
/*
 * STM32F2 hardware SHA1 support through the STM32F2 standard peripheral
 * library. Documentation located in STM32F2xx Standard Peripheral Library
 * document (See note in README).
 */
#include "stm32f2xx.h"
#include "stm32f2xx_hash.h"

int wc_InitSha(Sha* sha)
{
    /* STM32F2 struct notes:
     * sha->buffer  = first 4 bytes used to hold partial block if needed
     * sha->buffLen = num bytes currently stored in sha->buffer
     * sha->loLen   = num bytes that have been written to STM32 FIFO
     */
    XMEMSET(sha->buffer, 0, SHA_REG_SIZE);
    sha->buffLen = 0;
    sha->loLen = 0;

    /* initialize HASH peripheral */
    HASH_DeInit();

    /* configure algo used, algo mode, datatype */
    HASH->CR &= ~ (HASH_CR_ALGO | HASH_CR_DATATYPE | HASH_CR_MODE);
    HASH->CR |= (HASH_AlgoSelection_SHA1 | HASH_AlgoMode_HASH
                 | HASH_DataType_8b);

    /* reset HASH processor */
    HASH->CR |= HASH_CR_INIT;

    return 0;
}

int wc_ShaUpdate(Sha* sha, const byte* data, word32 len)
{
    word32 i = 0;
    word32 fill = 0;
    word32 diff = 0;

    /* if saved partial block is available */
    if (sha->buffLen) {
        fill = 4 - sha->buffLen;

        /* if enough data to fill, fill and push to FIFO */
        if (fill <= len) {
            XMEMCPY((byte*)sha->buffer + sha->buffLen, data, fill);
            HASH_DataIn(*(uint32_t*)sha->buffer);

            data += fill;
            len -= fill;
            sha->loLen += 4;
            sha->buffLen = 0;
        } else {
            /* append partial to existing stored block */
            XMEMCPY((byte*)sha->buffer + sha->buffLen, data, len);
            sha->buffLen += len;
            return;
        }
    }

    /* write input block in the IN FIFO */
    for(i = 0; i < len; i += 4)
    {
        diff = len - i;
        if ( diff < 4) {
            /* store incomplete last block, not yet in FIFO */
            XMEMSET(sha->buffer, 0, SHA_REG_SIZE);
            XMEMCPY((byte*)sha->buffer, data, diff);
            sha->buffLen = diff;
        } else {
            HASH_DataIn(*(uint32_t*)data);
            data+=4;
        }
    }

    /* keep track of total data length thus far */
    sha->loLen += (len - sha->buffLen);

    return 0;
}

int wc_ShaFinal(Sha* sha, byte* hash)
{
    __IO uint16_t nbvalidbitsdata = 0;

    /* finish reading any trailing bytes into FIFO */
    if (sha->buffLen) {
        HASH_DataIn(*(uint32_t*)sha->buffer);
        sha->loLen += sha->buffLen;
    }

    /* calculate number of valid bits in last word of input data */
    nbvalidbitsdata = 8 * (sha->loLen % SHA_REG_SIZE);

    /* configure number of valid bits in last word of the data */
    HASH_SetLastWordValidBitsNbr(nbvalidbitsdata);

    /* start HASH processor */
    HASH_StartDigest();

    /* wait until Busy flag == RESET */
    while (HASH_GetFlagStatus(HASH_FLAG_BUSY) != RESET) {}

    /* read message digest */
    sha->digest[0] = HASH->HR[0];
    sha->digest[1] = HASH->HR[1];
    sha->digest[2] = HASH->HR[2];
    sha->digest[3] = HASH->HR[3];
    sha->digest[4] = HASH->HR[4];

    ByteReverseWords(sha->digest, sha->digest, SHA_DIGEST_SIZE);

    XMEMCPY(hash, sha->digest, SHA_DIGEST_SIZE);

    return wc_InitSha(sha);  /* reset state */
}

#else /* wc_ software implementation */

#ifndef min

static INLINE word32 min(word32 a, word32 b)
{
    return a > b ? b : a;
}

#endif /* min */


int wc_InitSha(Sha* sha)
{
#ifdef FREESCALE_MMCAU
    cau_sha1_initialize_output(sha->digest);
#else
    sha->digest[0] = 0x67452301L;
    sha->digest[1] = 0xEFCDAB89L;
    sha->digest[2] = 0x98BADCFEL;
    sha->digest[3] = 0x10325476L;
    sha->digest[4] = 0xC3D2E1F0L;
#endif

    sha->buffLen = 0;
    sha->loLen   = 0;
    sha->hiLen   = 0;

    return 0;
}

#ifndef FREESCALE_MMCAU

#define blk0(i) (W[i] = sha->buffer[i])
#define blk1(i) (W[(i)&15] = \
rotlFixed(W[((i)+13)&15]^W[((i)+8)&15]^W[((i)+2)&15]^W[(i)&15],1))

#define f1(x,y,z) ((z)^((x) &((y)^(z))))
#define f2(x,y,z) ((x)^(y)^(z))
#define f3(x,y,z) (((x)&(y))|((z)&((x)|(y))))
#define f4(x,y,z) ((x)^(y)^(z))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define R0(v,w,x,y,z,i) (z)+= f1((w),(x),(y)) + blk0((i)) + 0x5A827999+ \
rotlFixed((v),5); (w) = rotlFixed((w),30);
#define R1(v,w,x,y,z,i) (z)+= f1((w),(x),(y)) + blk1((i)) + 0x5A827999+ \
rotlFixed((v),5); (w) = rotlFixed((w),30);
#define R2(v,w,x,y,z,i) (z)+= f2((w),(x),(y)) + blk1((i)) + 0x6ED9EBA1+ \
rotlFixed((v),5); (w) = rotlFixed((w),30);
#define R3(v,w,x,y,z,i) (z)+= f3((w),(x),(y)) + blk1((i)) + 0x8F1BBCDC+ \
rotlFixed((v),5); (w) = rotlFixed((w),30);
#define R4(v,w,x,y,z,i) (z)+= f4((w),(x),(y)) + blk1((i)) + 0xCA62C1D6+ \
rotlFixed((v),5); (w) = rotlFixed((w),30);

static void Transform(Sha* sha)
{
    word32 W[SHA_BLOCK_SIZE / sizeof(word32)];

    /* Copy context->state[] to working vars */
    word32 a = sha->digest[0];
    word32 b = sha->digest[1];
    word32 c = sha->digest[2];
    word32 d = sha->digest[3];
    word32 e = sha->digest[4];

#ifdef USE_SLOW_SHA
    word32 t, i;

    for (i = 0; i < 16; i++) {
        R0(a, b, c, d, e, i);
        t = e; e = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 20; i++) {
        R1(a, b, c, d, e, i);
        t = e; e = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 40; i++) {
        R2(a, b, c, d, e, i);
        t = e; e = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 60; i++) {
        R3(a, b, c, d, e, i);
        t = e; e = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 80; i++) {
        R4(a, b, c, d, e, i);
        t = e; e = d; d = c; c = b; b = a; a = t;
    }
#else
    /* nearly 1 K bigger in code size but 25% faster  */
    /* 4 rounds of 20 operations each. Loop unrolled. */
    R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
    R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
    R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
    R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);

    R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);

    R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
    R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
    R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
    R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
    R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);

    R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
    R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
    R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
    R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
    R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);

    R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
    R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
    R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
    R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
    R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
#endif

    /* Add the working vars back into digest state[] */
    sha->digest[0] += a;
    sha->digest[1] += b;
    sha->digest[2] += c;
    sha->digest[3] += d;
    sha->digest[4] += e;
}

#endif /* FREESCALE_MMCAU */


static INLINE void AddLength(Sha* sha, word32 len)
{
    word32 tmp = sha->loLen;
    if ( (sha->loLen += len) < tmp)
        sha->hiLen++;                       /* carry low to high */
}


int wc_ShaUpdate(Sha* sha, const byte* data, word32 len)
{
    /* do block size increments */
    byte* local = (byte*)sha->buffer;

    while (len) {
        word32 add = min(len, SHA_BLOCK_SIZE - sha->buffLen);
        XMEMCPY(&local[sha->buffLen], data, add);

        sha->buffLen += add;
        data         += add;
        len          -= add;

        if (sha->buffLen == SHA_BLOCK_SIZE) {
#if defined(LITTLE_ENDIAN_ORDER) && !defined(FREESCALE_MMCAU)
            ByteReverseWords(sha->buffer, sha->buffer, SHA_BLOCK_SIZE);
#endif
            XTRANSFORM(sha, local);
            AddLength(sha, SHA_BLOCK_SIZE);
            sha->buffLen = 0;
        }
    }

    return 0;
}


int wc_ShaFinal(Sha* sha, byte* hash)
{
    byte* local = (byte*)sha->buffer;

    AddLength(sha, sha->buffLen);  /* before adding pads */

    local[sha->buffLen++] = 0x80;  /* add 1 */

    /* pad with zeros */
    if (sha->buffLen > SHA_PAD_SIZE) {
        XMEMSET(&local[sha->buffLen], 0, SHA_BLOCK_SIZE - sha->buffLen);
        sha->buffLen += SHA_BLOCK_SIZE - sha->buffLen;

#if defined(LITTLE_ENDIAN_ORDER) && !defined(FREESCALE_MMCAU)
        ByteReverseWords(sha->buffer, sha->buffer, SHA_BLOCK_SIZE);
#endif
        XTRANSFORM(sha, local);
        sha->buffLen = 0;
    }
    XMEMSET(&local[sha->buffLen], 0, SHA_PAD_SIZE - sha->buffLen);

    /* put lengths in bits */
    sha->hiLen = (sha->loLen >> (8*sizeof(sha->loLen) - 3)) +
    (sha->hiLen << 3);
    sha->loLen = sha->loLen << 3;

    /* store lengths */
#if defined(LITTLE_ENDIAN_ORDER) && !defined(FREESCALE_MMCAU)
    ByteReverseWords(sha->buffer, sha->buffer, SHA_BLOCK_SIZE);
#endif
    /* ! length ordering dependent on digest endian type ! */
    XMEMCPY(&local[SHA_PAD_SIZE], &sha->hiLen, sizeof(word32));
    XMEMCPY(&local[SHA_PAD_SIZE + sizeof(word32)], &sha->loLen, sizeof(word32));

#ifdef FREESCALE_MMCAU
    /* Kinetis requires only these bytes reversed */
    ByteReverseWords(&sha->buffer[SHA_PAD_SIZE/sizeof(word32)],
                     &sha->buffer[SHA_PAD_SIZE/sizeof(word32)],
                     2 * sizeof(word32));
#endif

    XTRANSFORM(sha, local);
#ifdef LITTLE_ENDIAN_ORDER
    ByteReverseWords(sha->digest, sha->digest, SHA_DIGEST_SIZE);
#endif
    XMEMCPY(hash, sha->digest, SHA_DIGEST_SIZE);

    return wc_InitSha(sha);  /* reset state */
}

#endif /* STM32F2_HASH */


int wc_ShaHash(const byte* data, word32 len, byte* hash)
{
    int ret = 0;
#ifdef WOLFSSL_SMALL_STACK
    Sha* sha;
#else
    Sha sha[1];
#endif

#ifdef WOLFSSL_SMALL_STACK
    sha = (Sha*)XMALLOC(sizeof(Sha), NULL, DYNAMIC_TYPE_TMP_BUFFER);
    if (sha == NULL)
        return MEMORY_E;
#endif

    if ((ret = wc_InitSha(sha)) != 0) {
        WOLFSSL_MSG("wc_InitSha failed");
    }
    else {
        wc_ShaUpdate(sha, data, len);
        wc_ShaFinal(sha, hash);
    }

#ifdef WOLFSSL_SMALL_STACK
    XFREE(sha, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

    return ret;

}
#endif /* HAVE_FIPS */
#endif /* NO_SHA */

