/*
** Copyright (c) 2017 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the Simplified BSD License (also
** known as the "2-Clause License" or "FreeBSD License".)
**
** This program 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.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*******************************************************************************
**
** This file contains an implementation of SHA3 (Keccak) hashing.
*/
#include "config.h"
#include "sha3.h"

/*
** Macros to determine whether the machine is big or little endian,
** and whether or not that determination is run-time or compile-time.
**
** For best performance, an attempt is made to guess at the byte-order
** using C-preprocessor macros.  If that is unsuccessful, or if
** -DSHA3_BYTEORDER=0 is set, then byte-order is determined
** at run-time.
*/
#ifndef SHA3_BYTEORDER
# if defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
     defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \
     defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \
     defined(__arm__)
#   define SHA3_BYTEORDER    1234
# elif defined(sparc)    || defined(__ppc__)
#   define SHA3_BYTEORDER    4321
# else
#   define SHA3_BYTEORDER 0
# endif
#endif


/*
** State structure for a SHA3 hash in progress
*/
typedef struct SHA3Context SHA3Context;
struct SHA3Context {
  union {
    u64 s[25];                /* Keccak state. 5x5 lines of 64 bits each */
    unsigned char x[1600];    /* ... or 1600 bytes */
  } u;
  unsigned nRate;        /* Bytes of input accepted per Keccak iteration */
  unsigned nLoaded;      /* Input bytes loaded into u.x[] so far this cycle */
  unsigned ixMask;       /* Insert next input into u.x[nLoaded^ixMask]. */
};

/*
** A single step of the Keccak mixing function for a 1600-bit state
*/
static void KeccakF1600Step(SHA3Context *p){
  int i;
  u64 B0, B1, B2, B3, B4;
  u64 C0, C1, C2, C3, C4;
  u64 D0, D1, D2, D3, D4;
  static const u64 RC[] = {
    0x0000000000000001ULL,  0x0000000000008082ULL,
    0x800000000000808aULL,  0x8000000080008000ULL,
    0x000000000000808bULL,  0x0000000080000001ULL,
    0x8000000080008081ULL,  0x8000000000008009ULL,
    0x000000000000008aULL,  0x0000000000000088ULL,
    0x0000000080008009ULL,  0x000000008000000aULL,
    0x000000008000808bULL,  0x800000000000008bULL,
    0x8000000000008089ULL,  0x8000000000008003ULL,
    0x8000000000008002ULL,  0x8000000000000080ULL,
    0x000000000000800aULL,  0x800000008000000aULL,
    0x8000000080008081ULL,  0x8000000000008080ULL,
    0x0000000080000001ULL,  0x8000000080008008ULL
  };
# define A00 (p->u.s[0])
# define A01 (p->u.s[1])
# define A02 (p->u.s[2])
# define A03 (p->u.s[3])
# define A04 (p->u.s[4])
# define A10 (p->u.s[5])
# define A11 (p->u.s[6])
# define A12 (p->u.s[7])
# define A13 (p->u.s[8])
# define A14 (p->u.s[9])
# define A20 (p->u.s[10])
# define A21 (p->u.s[11])
# define A22 (p->u.s[12])
# define A23 (p->u.s[13])
# define A24 (p->u.s[14])
# define A30 (p->u.s[15])
# define A31 (p->u.s[16])
# define A32 (p->u.s[17])
# define A33 (p->u.s[18])
# define A34 (p->u.s[19])
# define A40 (p->u.s[20])
# define A41 (p->u.s[21])
# define A42 (p->u.s[22])
# define A43 (p->u.s[23])
# define A44 (p->u.s[24])
# define ROL64(a,x) ((a<<x)|(a>>(64-x)))

  for(i=0; i<24; i+=4){
    C0 = A00^A10^A20^A30^A40;
    C1 = A01^A11^A21^A31^A41;
    C2 = A02^A12^A22^A32^A42;
    C3 = A03^A13^A23^A33^A43;
    C4 = A04^A14^A24^A34^A44;
    D0 = C4^ROL64(C1, 1);
    D1 = C0^ROL64(C2, 1);
    D2 = C1^ROL64(C3, 1);
    D3 = C2^ROL64(C4, 1);
    D4 = C3^ROL64(C0, 1);

    B0 = (A00^D0);
    B1 = ROL64((A11^D1), 44);
    B2 = ROL64((A22^D2), 43);
    B3 = ROL64((A33^D3), 21);
    B4 = ROL64((A44^D4), 14);
    A00 =   B0 ^((~B1)&  B2 );
    A00 ^= RC[i];
    A11 =   B1 ^((~B2)&  B3 );
    A22 =   B2 ^((~B3)&  B4 );
    A33 =   B3 ^((~B4)&  B0 );
    A44 =   B4 ^((~B0)&  B1 );

    B2 = ROL64((A20^D0), 3);
    B3 = ROL64((A31^D1), 45);
    B4 = ROL64((A42^D2), 61);
    B0 = ROL64((A03^D3), 28);
    B1 = ROL64((A14^D4), 20);
    A20 =   B0 ^((~B1)&  B2 );
    A31 =   B1 ^((~B2)&  B3 );
    A42 =   B2 ^((~B3)&  B4 );
    A03 =   B3 ^((~B4)&  B0 );
    A14 =   B4 ^((~B0)&  B1 );

    B4 = ROL64((A40^D0), 18);
    B0 = ROL64((A01^D1), 1);
    B1 = ROL64((A12^D2), 6);
    B2 = ROL64((A23^D3), 25);
    B3 = ROL64((A34^D4), 8);
    A40 =   B0 ^((~B1)&  B2 );
    A01 =   B1 ^((~B2)&  B3 );
    A12 =   B2 ^((~B3)&  B4 );
    A23 =   B3 ^((~B4)&  B0 );
    A34 =   B4 ^((~B0)&  B1 );

    B1 = ROL64((A10^D0), 36);
    B2 = ROL64((A21^D1), 10);
    B3 = ROL64((A32^D2), 15);
    B4 = ROL64((A43^D3), 56);
    B0 = ROL64((A04^D4), 27);
    A10 =   B0 ^((~B1)&  B2 );
    A21 =   B1 ^((~B2)&  B3 );
    A32 =   B2 ^((~B3)&  B4 );
    A43 =   B3 ^((~B4)&  B0 );
    A04 =   B4 ^((~B0)&  B1 );

    B3 = ROL64((A30^D0), 41);
    B4 = ROL64((A41^D1), 2);
    B0 = ROL64((A02^D2), 62);
    B1 = ROL64((A13^D3), 55);
    B2 = ROL64((A24^D4), 39);
    A30 =   B0 ^((~B1)&  B2 );
    A41 =   B1 ^((~B2)&  B3 );
    A02 =   B2 ^((~B3)&  B4 );
    A13 =   B3 ^((~B4)&  B0 );
    A24 =   B4 ^((~B0)&  B1 );

    C0 = A00^A20^A40^A10^A30;
    C1 = A11^A31^A01^A21^A41;
    C2 = A22^A42^A12^A32^A02;
    C3 = A33^A03^A23^A43^A13;
    C4 = A44^A14^A34^A04^A24;
    D0 = C4^ROL64(C1, 1);
    D1 = C0^ROL64(C2, 1);
    D2 = C1^ROL64(C3, 1);
    D3 = C2^ROL64(C4, 1);
    D4 = C3^ROL64(C0, 1);

    B0 = (A00^D0);
    B1 = ROL64((A31^D1), 44);
    B2 = ROL64((A12^D2), 43);
    B3 = ROL64((A43^D3), 21);
    B4 = ROL64((A24^D4), 14);
    A00 =   B0 ^((~B1)&  B2 );
    A00 ^= RC[i+1];
    A31 =   B1 ^((~B2)&  B3 );
    A12 =   B2 ^((~B3)&  B4 );
    A43 =   B3 ^((~B4)&  B0 );
    A24 =   B4 ^((~B0)&  B1 );

    B2 = ROL64((A40^D0), 3);
    B3 = ROL64((A21^D1), 45);
    B4 = ROL64((A02^D2), 61);
    B0 = ROL64((A33^D3), 28);
    B1 = ROL64((A14^D4), 20);
    A40 =   B0 ^((~B1)&  B2 );
    A21 =   B1 ^((~B2)&  B3 );
    A02 =   B2 ^((~B3)&  B4 );
    A33 =   B3 ^((~B4)&  B0 );
    A14 =   B4 ^((~B0)&  B1 );

    B4 = ROL64((A30^D0), 18);
    B0 = ROL64((A11^D1), 1);
    B1 = ROL64((A42^D2), 6);
    B2 = ROL64((A23^D3), 25);
    B3 = ROL64((A04^D4), 8);
    A30 =   B0 ^((~B1)&  B2 );
    A11 =   B1 ^((~B2)&  B3 );
    A42 =   B2 ^((~B3)&  B4 );
    A23 =   B3 ^((~B4)&  B0 );
    A04 =   B4 ^((~B0)&  B1 );

    B1 = ROL64((A20^D0), 36);
    B2 = ROL64((A01^D1), 10);
    B3 = ROL64((A32^D2), 15);
    B4 = ROL64((A13^D3), 56);
    B0 = ROL64((A44^D4), 27);
    A20 =   B0 ^((~B1)&  B2 );
    A01 =   B1 ^((~B2)&  B3 );
    A32 =   B2 ^((~B3)&  B4 );
    A13 =   B3 ^((~B4)&  B0 );
    A44 =   B4 ^((~B0)&  B1 );

    B3 = ROL64((A10^D0), 41);
    B4 = ROL64((A41^D1), 2);
    B0 = ROL64((A22^D2), 62);
    B1 = ROL64((A03^D3), 55);
    B2 = ROL64((A34^D4), 39);
    A10 =   B0 ^((~B1)&  B2 );
    A41 =   B1 ^((~B2)&  B3 );
    A22 =   B2 ^((~B3)&  B4 );
    A03 =   B3 ^((~B4)&  B0 );
    A34 =   B4 ^((~B0)&  B1 );

    C0 = A00^A40^A30^A20^A10;
    C1 = A31^A21^A11^A01^A41;
    C2 = A12^A02^A42^A32^A22;
    C3 = A43^A33^A23^A13^A03;
    C4 = A24^A14^A04^A44^A34;
    D0 = C4^ROL64(C1, 1);
    D1 = C0^ROL64(C2, 1);
    D2 = C1^ROL64(C3, 1);
    D3 = C2^ROL64(C4, 1);
    D4 = C3^ROL64(C0, 1);

    B0 = (A00^D0);
    B1 = ROL64((A21^D1), 44);
    B2 = ROL64((A42^D2), 43);
    B3 = ROL64((A13^D3), 21);
    B4 = ROL64((A34^D4), 14);
    A00 =   B0 ^((~B1)&  B2 );
    A00 ^= RC[i+2];
    A21 =   B1 ^((~B2)&  B3 );
    A42 =   B2 ^((~B3)&  B4 );
    A13 =   B3 ^((~B4)&  B0 );
    A34 =   B4 ^((~B0)&  B1 );

    B2 = ROL64((A30^D0), 3);
    B3 = ROL64((A01^D1), 45);
    B4 = ROL64((A22^D2), 61);
    B0 = ROL64((A43^D3), 28);
    B1 = ROL64((A14^D4), 20);
    A30 =   B0 ^((~B1)&  B2 );
    A01 =   B1 ^((~B2)&  B3 );
    A22 =   B2 ^((~B3)&  B4 );
    A43 =   B3 ^((~B4)&  B0 );
    A14 =   B4 ^((~B0)&  B1 );

    B4 = ROL64((A10^D0), 18);
    B0 = ROL64((A31^D1), 1);
    B1 = ROL64((A02^D2), 6);
    B2 = ROL64((A23^D3), 25);
    B3 = ROL64((A44^D4), 8);
    A10 =   B0 ^((~B1)&  B2 );
    A31 =   B1 ^((~B2)&  B3 );
    A02 =   B2 ^((~B3)&  B4 );
    A23 =   B3 ^((~B4)&  B0 );
    A44 =   B4 ^((~B0)&  B1 );

    B1 = ROL64((A40^D0), 36);
    B2 = ROL64((A11^D1), 10);
    B3 = ROL64((A32^D2), 15);
    B4 = ROL64((A03^D3), 56);
    B0 = ROL64((A24^D4), 27);
    A40 =   B0 ^((~B1)&  B2 );
    A11 =   B1 ^((~B2)&  B3 );
    A32 =   B2 ^((~B3)&  B4 );
    A03 =   B3 ^((~B4)&  B0 );
    A24 =   B4 ^((~B0)&  B1 );

    B3 = ROL64((A20^D0), 41);
    B4 = ROL64((A41^D1), 2);
    B0 = ROL64((A12^D2), 62);
    B1 = ROL64((A33^D3), 55);
    B2 = ROL64((A04^D4), 39);
    A20 =   B0 ^((~B1)&  B2 );
    A41 =   B1 ^((~B2)&  B3 );
    A12 =   B2 ^((~B3)&  B4 );
    A33 =   B3 ^((~B4)&  B0 );
    A04 =   B4 ^((~B0)&  B1 );

    C0 = A00^A30^A10^A40^A20;
    C1 = A21^A01^A31^A11^A41;
    C2 = A42^A22^A02^A32^A12;
    C3 = A13^A43^A23^A03^A33;
    C4 = A34^A14^A44^A24^A04;
    D0 = C4^ROL64(C1, 1);
    D1 = C0^ROL64(C2, 1);
    D2 = C1^ROL64(C3, 1);
    D3 = C2^ROL64(C4, 1);
    D4 = C3^ROL64(C0, 1);

    B0 = (A00^D0);
    B1 = ROL64((A01^D1), 44);
    B2 = ROL64((A02^D2), 43);
    B3 = ROL64((A03^D3), 21);
    B4 = ROL64((A04^D4), 14);
    A00 =   B0 ^((~B1)&  B2 );
    A00 ^= RC[i+3];
    A01 =   B1 ^((~B2)&  B3 );
    A02 =   B2 ^((~B3)&  B4 );
    A03 =   B3 ^((~B4)&  B0 );
    A04 =   B4 ^((~B0)&  B1 );

    B2 = ROL64((A10^D0), 3);
    B3 = ROL64((A11^D1), 45);
    B4 = ROL64((A12^D2), 61);
    B0 = ROL64((A13^D3), 28);
    B1 = ROL64((A14^D4), 20);
    A10 =   B0 ^((~B1)&  B2 );
    A11 =   B1 ^((~B2)&  B3 );
    A12 =   B2 ^((~B3)&  B4 );
    A13 =   B3 ^((~B4)&  B0 );
    A14 =   B4 ^((~B0)&  B1 );

    B4 = ROL64((A20^D0), 18);
    B0 = ROL64((A21^D1), 1);
    B1 = ROL64((A22^D2), 6);
    B2 = ROL64((A23^D3), 25);
    B3 = ROL64((A24^D4), 8);
    A20 =   B0 ^((~B1)&  B2 );
    A21 =   B1 ^((~B2)&  B3 );
    A22 =   B2 ^((~B3)&  B4 );
    A23 =   B3 ^((~B4)&  B0 );
    A24 =   B4 ^((~B0)&  B1 );

    B1 = ROL64((A30^D0), 36);
    B2 = ROL64((A31^D1), 10);
    B3 = ROL64((A32^D2), 15);
    B4 = ROL64((A33^D3), 56);
    B0 = ROL64((A34^D4), 27);
    A30 =   B0 ^((~B1)&  B2 );
    A31 =   B1 ^((~B2)&  B3 );
    A32 =   B2 ^((~B3)&  B4 );
    A33 =   B3 ^((~B4)&  B0 );
    A34 =   B4 ^((~B0)&  B1 );

    B3 = ROL64((A40^D0), 41);
    B4 = ROL64((A41^D1), 2);
    B0 = ROL64((A42^D2), 62);
    B1 = ROL64((A43^D3), 55);
    B2 = ROL64((A44^D4), 39);
    A40 =   B0 ^((~B1)&  B2 );
    A41 =   B1 ^((~B2)&  B3 );
    A42 =   B2 ^((~B3)&  B4 );
    A43 =   B3 ^((~B4)&  B0 );
    A44 =   B4 ^((~B0)&  B1 );
  }
}

/*
** Initialize a new hash.  iSize determines the size of the hash
** in bits and should be one of 224, 256, 384, or 512.  Or iSize
** can be zero to use the default hash size of 256 bits.
*/
static void SHA3Init(SHA3Context *p, int iSize){
  memset(p, 0, sizeof(*p));
  if( iSize>=128 && iSize<=512 ){
    p->nRate = (1600 - ((iSize + 31)&~31)*2)/8;
  }else{
    p->nRate = (1600 - 2*256)/8;
  }
#if SHA3_BYTEORDER==1234
  /* Known to be little-endian at compile-time. No-op */
#elif SHA3_BYTEORDER==4321
  p->ixMask = 7;  /* Big-endian */
#else
  {
    static unsigned int one = 1;
    if( 1==*(unsigned char*)&one ){
      /* Little endian.  No byte swapping. */
      p->ixMask = 0;
    }else{
      /* Big endian.  Byte swap. */
      p->ixMask = 7;
    }
  }
#endif
}

/*
** Make consecutive calls to the SHA3Update function to add new content
** to the hash
*/
static void SHA3Update(
  SHA3Context *p,
  const unsigned char *aData,
  unsigned int nData
){
  unsigned int i = 0;
#if SHA3_BYTEORDER==1234
  if( (p->nLoaded % 8)==0 && ((aData - (const unsigned char*)0)&7)==0 ){
    for(; i+7<nData; i+=8){
      p->u.s[p->nLoaded/8] ^= *(u64*)&aData[i];
      p->nLoaded += 8;
      if( p->nLoaded>=p->nRate ){
        KeccakF1600Step(p);
        p->nLoaded = 0;
      }
    }
  }
#endif
  for(; i<nData; i++){
#if SHA3_BYTEORDER==1234
    p->u.x[p->nLoaded] ^= aData[i];
#elif SHA3_BYTEORDER==4321
    p->u.x[p->nLoaded^0x07] ^= aData[i];
#else
    p->u.x[p->nLoaded^p->ixMask] ^= aData[i];
#endif
    p->nLoaded++;
    if( p->nLoaded==p->nRate ){
      KeccakF1600Step(p);
      p->nLoaded = 0;
    }
  }
}

/*
** After all content has been added, invoke SHA3Final() to compute
** the final hash.  The function returns a pointer to the binary
** hash value.
*/
static unsigned char *SHA3Final(SHA3Context *p){
  unsigned int i;
  if( p->nLoaded==p->nRate-1 ){
    const unsigned char c1 = 0x86;
    SHA3Update(p, &c1, 1);
  }else{
    const unsigned char c2 = 0x06;
    const unsigned char c3 = 0x80;
    SHA3Update(p, &c2, 1);
    p->nLoaded = p->nRate - 1;
    SHA3Update(p, &c3, 1);
  }
  for(i=0; i<p->nRate; i++){
    p->u.x[i+p->nRate] = p->u.x[i^p->ixMask];
  }
  return &p->u.x[p->nRate];
}

/*
** Convert a digest into base-16.  digest should be declared as
** "unsigned char digest[20]" in the calling function.  The SHA3
** digest is stored in the first 20 bytes.  zBuf should
** be "char zBuf[41]".
*/
static void DigestToBase16(unsigned char *digest, char *zBuf, int nByte){
  static const char zEncode[] = "0123456789abcdef";
  int ix;

  for(ix=0; ix<nByte; ix++){
    *zBuf++ = zEncode[(*digest>>4)&0xf];
    *zBuf++ = zEncode[*digest++ & 0xf];
  }
  *zBuf = '\0';
}

/*
** The state of an incremental SHA3 checksum computation.  Only one
** such computation can be underway at a time, of course.
*/
static SHA3Context incrCtx;
static int incrInit = 0;

/*
** Initialize a new global SHA3 hash.
*/
void sha3sum_init(int iSize){
  assert( incrInit==0 );
  incrInit = iSize;
  SHA3Init(&incrCtx, incrInit);
}

/*
** Add more text to the incremental SHA3 checksum.
*/
void sha3sum_step_text(const char *zText, int nBytes){
  assert( incrInit );
  if( nBytes<=0 ){
    if( nBytes==0 ) return;
    nBytes = strlen(zText);
  }
  SHA3Update(&incrCtx, (unsigned char*)zText, nBytes);
}

/*
** Add the content of a blob to the incremental SHA3 checksum.
*/
void sha3sum_step_blob(Blob *p){
  assert( incrInit );
  SHA3Update(&incrCtx, (unsigned char*)blob_buffer(p), blob_size(p));
}

/*
** Finish the incremental SHA3 checksum.  Store the result in blob pOut
** if pOut!=0.  Also return a pointer to the result.
**
** This resets the incremental checksum preparing for the next round
** of computation.  The return pointer points to a static buffer that
** is overwritten by subsequent calls to this function.
*/
char *sha3sum_finish(Blob *pOut){
  static char zOut[132];
  DigestToBase16(SHA3Final(&incrCtx), zOut, incrInit/8);
  if( pOut ){
    blob_zero(pOut);
    blob_append(pOut, zOut, incrInit/4);
  }
  incrInit = 0;
  return zOut;
}


/*
** Compute the SHA3 checksum of a file on disk.  Store the resulting
** checksum in the blob pCksum.  pCksum is assumed to be initialized.
**
** Return the number of errors.
*/
int sha3sum_file(const char *zFilename, int eFType, int iSize, Blob *pCksum){
  FILE *in;
  SHA3Context ctx;
  char zBuf[10240];

  if( eFType==RepoFILE && file_islink(zFilename) ){
    /* Instead of file content, return sha3 of link destination path */
    Blob destinationPath;
    int rc;

    blob_read_link(&destinationPath, zFilename);
    rc = sha3sum_blob(&destinationPath, iSize, pCksum);
    blob_reset(&destinationPath);
    return rc;
  }

  in = fossil_fopen(zFilename,"rb");
  if( in==0 ){
    return 1;
  }
  SHA3Init(&ctx, iSize);
  for(;;){
    int n;
    n = fread(zBuf, 1, sizeof(zBuf), in);
    if( n<=0 ) break;
    SHA3Update(&ctx, (unsigned char*)zBuf, (unsigned)n);
  }
  fclose(in);
  blob_zero(pCksum);
  blob_resize(pCksum, iSize/4);
  DigestToBase16(SHA3Final(&ctx), blob_buffer(pCksum), iSize/8);
  return 0;
}

/*
** Compute the SHA3 checksum of a blob in memory.  Store the resulting
** checksum in the blob pCksum.  pCksum is assumed to be either
** uninitialized or the same blob as pIn.
**
** Return the number of errors.
*/
int sha3sum_blob(const Blob *pIn, int iSize, Blob *pCksum){
  SHA3Context ctx;
  SHA3Init(&ctx, iSize);
  SHA3Update(&ctx, (unsigned char*)blob_buffer(pIn), blob_size(pIn));
  if( pIn==pCksum ){
    blob_reset(pCksum);
  }else{
    blob_zero(pCksum);
  }
  blob_resize(pCksum, iSize/4);
  DigestToBase16(SHA3Final(&ctx), blob_buffer(pCksum), iSize/8);
  return 0;
}

#if 0 /* NOT USED */
/*
** Compute the SHA3 checksum of a zero-terminated string.  The
** result is held in memory obtained from mprintf().
*/
char *sha3sum(const char *zIn, int iSize){
  SHA3Context ctx;
  char zDigest[132];

  SHA3Init(&ctx, iSize);
  SHA3Update(&ctx, (unsigned const char*)zIn, strlen(zIn));
  DigestToBase16(SHA3Final(&ctx), zDigest, iSize/8);
  return mprintf("%s", zDigest);
}
#endif

/*
** COMMAND: sha3sum*
**
** Usage: %fossil sha3sum FILE...
**
** Compute an SHA3 checksum of all files named on the command-line.
** If a file is named "-" then take its content from standard input.
**
** To be clear:  The official NIST FIPS-202 implementation of SHA3
** with the added 01 padding is used, not the original Keccak submission.
**
** Options:
**
**    --224               Compute a SHA3-224 hash
**    --256               Compute a SHA3-256 hash (the default)
**    --384               Compute a SHA3-384 hash
**    --512               Compute a SHA3-512 hash
**    --size N            An N-bit hash.  N must be a multiple of 32 between
**                        128 and 512.
**    -h|--dereference    If FILE is a symbolic link, compute the hash on
**                        the object pointed to, not on the link itself.
**
** See also: [[md5sum]], [[sha1sum]]
*/
void sha3sum_test(void){
  int i;
  Blob in;
  Blob cksum = empty_blob;
  int iSize = 256;
  int eFType = SymFILE;

  if( find_option("dereference","h",0) ) eFType = ExtFILE;
  if( find_option("224",0,0)!=0 ) iSize = 224;
  else if( find_option("256",0,0)!=0 ) iSize = 256;
  else if( find_option("384",0,0)!=0 ) iSize = 384;
  else if( find_option("512",0,0)!=0 ) iSize = 512;
  else{
    const char *zN = find_option("size",0,1);
    if( zN!=0 ){
      int n = atoi(zN);
      if( n%32!=0 || n<128 || n>512 ){
        fossil_fatal("--size must be a multiple of 64 between 128 and 512");
      }
      iSize = n;
    }
  }
  verify_all_options();

  for(i=2; i<g.argc; i++){
    if( g.argv[i][0]=='-' && g.argv[i][1]==0 ){
      blob_read_from_channel(&in, stdin, -1);
      sha3sum_blob(&in, iSize, &cksum);
    }else if( sha3sum_file(g.argv[i], eFType, iSize, &cksum) > 0 ){
      fossil_fatal("Cannot read file: %s", g.argv[i]);
    }
    fossil_print("%s  %s\n", blob_str(&cksum), g.argv[i]);
    blob_reset(&cksum);
  }
}
