/*
   BLAKE2 reference source code package - reference C implementations

   Written in 2012 by Samuel Neves <sneves@dei.uc.pt>

   To the extent possible under law, the author(s) have dedicated all copyright
   and related and neighboring rights to this software to the public domain
   worldwide. This software is distributed without any warranty.

   You should have received a copy of the CC0 Public Domain Dedication along with
   this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
*/
/* blake2b.c
 *
 * Copyright (C) 2006-2013 wolfSSL Inc.
 *
 * This file is part of CyaSSL.
 *
 * CyaSSL 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.
 *
 * CyaSSL 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */


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

#include <cyassl/ctaocrypt/settings.h>

#ifdef HAVE_BLAKE2

#include <cyassl/ctaocrypt/blake2.h>
#include <cyassl/ctaocrypt/blake2-impl.h>


static const word64 blake2b_IV[8] =
{
  0x6a09e667f3bcc908ULL, 0xbb67ae8584caa73bULL,
  0x3c6ef372fe94f82bULL, 0xa54ff53a5f1d36f1ULL,
  0x510e527fade682d1ULL, 0x9b05688c2b3e6c1fULL,
  0x1f83d9abfb41bd6bULL, 0x5be0cd19137e2179ULL
};

static const byte blake2b_sigma[12][16] =
{
  {  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15 } ,
  { 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3 } ,
  { 11,  8, 12,  0,  5,  2, 15, 13, 10, 14,  3,  6,  7,  1,  9,  4 } ,
  {  7,  9,  3,  1, 13, 12, 11, 14,  2,  6,  5, 10,  4,  0, 15,  8 } ,
  {  9,  0,  5,  7,  2,  4, 10, 15, 14,  1, 11, 12,  6,  8,  3, 13 } ,
  {  2, 12,  6, 10,  0, 11,  8,  3,  4, 13,  7,  5, 15, 14,  1,  9 } ,
  { 12,  5,  1, 15, 14, 13,  4, 10,  0,  7,  6,  3,  9,  2,  8, 11 } ,
  { 13, 11,  7, 14, 12,  1,  3,  9,  5,  0, 15,  4,  8,  6,  2, 10 } ,
  {  6, 15, 14,  9, 11,  3,  0,  8, 12,  2, 13,  7,  1,  4, 10,  5 } ,
  { 10,  2,  8,  4,  7,  6,  1,  5, 15, 11,  9, 14,  3, 12, 13 , 0 } ,
  {  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15 } ,
  { 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3 }
};


static INLINE int blake2b_set_lastnode( blake2b_state *S )
{
  S->f[1] = ~0ULL;
  return 0;
}

/* Some helper functions, not necessarily useful */
static INLINE int blake2b_set_lastblock( blake2b_state *S )
{
  if( S->last_node ) blake2b_set_lastnode( S );

  S->f[0] = ~0ULL;
  return 0;
}

static INLINE int blake2b_increment_counter( blake2b_state *S, const word64
                                             inc )
{
  S->t[0] += inc;
  S->t[1] += ( S->t[0] < inc );
  return 0;
}

static INLINE int blake2b_init0( blake2b_state *S )
{
  int i;
  XMEMSET( S, 0, sizeof( blake2b_state ) );

  for( i = 0; i < 8; ++i ) S->h[i] = blake2b_IV[i];

  return 0;
}

/* init xors IV with input parameter block */
int blake2b_init_param( blake2b_state *S, const blake2b_param *P )
{
  word32 i;
  blake2b_init0( S );
  byte *p = ( byte * )( P );

  /* IV XOR ParamBlock */
  for( i = 0; i < 8; ++i )
    S->h[i] ^= load64( p + sizeof( S->h[i] ) * i );

  return 0;
}



int blake2b_init( blake2b_state *S, const byte outlen )
{
  blake2b_param P[1];

  if ( ( !outlen ) || ( outlen > BLAKE2B_OUTBYTES ) ) return -1;

  P->digest_length = outlen;
  P->key_length    = 0;
  P->fanout        = 1;
  P->depth         = 1;
  store32( &P->leaf_length, 0 );
  store64( &P->node_offset, 0 );
  P->node_depth    = 0;
  P->inner_length  = 0;
  XMEMSET( P->reserved, 0, sizeof( P->reserved ) );
  XMEMSET( P->salt,     0, sizeof( P->salt ) );
  XMEMSET( P->personal, 0, sizeof( P->personal ) );
  return blake2b_init_param( S, P );
}


int blake2b_init_key( blake2b_state *S, const byte outlen, const void *key,
                      const byte keylen )
{
  blake2b_param P[1];

  if ( ( !outlen ) || ( outlen > BLAKE2B_OUTBYTES ) ) return -1;

  if ( !key || !keylen || keylen > BLAKE2B_KEYBYTES ) return -1;

  P->digest_length = outlen;
  P->key_length    = keylen;
  P->fanout        = 1;
  P->depth         = 1;
  store32( &P->leaf_length, 0 );
  store64( &P->node_offset, 0 );
  P->node_depth    = 0;
  P->inner_length  = 0;
  XMEMSET( P->reserved, 0, sizeof( P->reserved ) );
  XMEMSET( P->salt,     0, sizeof( P->salt ) );
  XMEMSET( P->personal, 0, sizeof( P->personal ) );

  if( blake2b_init_param( S, P ) < 0 ) return -1;

  {
    byte block[BLAKE2B_BLOCKBYTES];
    XMEMSET( block, 0, BLAKE2B_BLOCKBYTES );
    XMEMCPY( block, key, keylen );
    blake2b_update( S, block, BLAKE2B_BLOCKBYTES );
    secure_zero_memory( block, BLAKE2B_BLOCKBYTES ); /* Burn the key from */
                                                     /*stack */
  }
  return 0;
}

static int blake2b_compress( blake2b_state *S,
                             const byte block[BLAKE2B_BLOCKBYTES] )
{
  word64 m[16];
  word64 v[16];
  int i;

  for( i = 0; i < 16; ++i )
    m[i] = load64( block + i * sizeof( m[i] ) );

  for( i = 0; i < 8; ++i )
    v[i] = S->h[i];

  v[ 8] = blake2b_IV[0];
  v[ 9] = blake2b_IV[1];
  v[10] = blake2b_IV[2];
  v[11] = blake2b_IV[3];
  v[12] = S->t[0] ^ blake2b_IV[4];
  v[13] = S->t[1] ^ blake2b_IV[5];
  v[14] = S->f[0] ^ blake2b_IV[6];
  v[15] = S->f[1] ^ blake2b_IV[7];
#define G(r,i,a,b,c,d) \
  do { \
    a = a + b + m[blake2b_sigma[r][2*i+0]]; \
    d = rotr64(d ^ a, 32); \
    c = c + d; \
    b = rotr64(b ^ c, 24); \
    a = a + b + m[blake2b_sigma[r][2*i+1]]; \
    d = rotr64(d ^ a, 16); \
    c = c + d; \
    b = rotr64(b ^ c, 63); \
  } while(0)
#define ROUND(r)  \
  do { \
    G(r,0,v[ 0],v[ 4],v[ 8],v[12]); \
    G(r,1,v[ 1],v[ 5],v[ 9],v[13]); \
    G(r,2,v[ 2],v[ 6],v[10],v[14]); \
    G(r,3,v[ 3],v[ 7],v[11],v[15]); \
    G(r,4,v[ 0],v[ 5],v[10],v[15]); \
    G(r,5,v[ 1],v[ 6],v[11],v[12]); \
    G(r,6,v[ 2],v[ 7],v[ 8],v[13]); \
    G(r,7,v[ 3],v[ 4],v[ 9],v[14]); \
  } while(0)
  ROUND( 0 );
  ROUND( 1 );
  ROUND( 2 );
  ROUND( 3 );
  ROUND( 4 );
  ROUND( 5 );
  ROUND( 6 );
  ROUND( 7 );
  ROUND( 8 );
  ROUND( 9 );
  ROUND( 10 );
  ROUND( 11 );

  for( i = 0; i < 8; ++i )
    S->h[i] = S->h[i] ^ v[i] ^ v[i + 8];

#undef G
#undef ROUND
  return 0;
}

/* inlen now in bytes */
int blake2b_update( blake2b_state *S, const byte *in, word64 inlen )
{
  while( inlen > 0 )
  {
    word64 left = S->buflen;
    word64 fill = 2 * BLAKE2B_BLOCKBYTES - left;

    if( inlen > fill )
    {
      XMEMCPY( S->buf + left, in, (word)fill ); /* Fill buffer */
      S->buflen += fill;
      blake2b_increment_counter( S, BLAKE2B_BLOCKBYTES );
      blake2b_compress( S, S->buf ); /* Compress */
      XMEMCPY( S->buf, S->buf + BLAKE2B_BLOCKBYTES, BLAKE2B_BLOCKBYTES );
              /* Shift buffer left */
      S->buflen -= BLAKE2B_BLOCKBYTES;
      in += fill;
      inlen -= fill;
    }
    else /* inlen <= fill */
    {
      XMEMCPY( S->buf + left, in, (word)inlen );
      S->buflen += inlen; /* Be lazy, do not compress */
      in += inlen;
      inlen -= inlen;
    }
  }

  return 0;
}

/* Is this correct? */
int blake2b_final( blake2b_state *S, byte *out, byte outlen )
{
  byte buffer[BLAKE2B_OUTBYTES];
  int     i;

  if( S->buflen > BLAKE2B_BLOCKBYTES )
  {
    blake2b_increment_counter( S, BLAKE2B_BLOCKBYTES );
    blake2b_compress( S, S->buf );
    S->buflen -= BLAKE2B_BLOCKBYTES;
    XMEMCPY( S->buf, S->buf + BLAKE2B_BLOCKBYTES, (word)S->buflen );
  }

  blake2b_increment_counter( S, S->buflen );
  blake2b_set_lastblock( S );
  XMEMSET( S->buf + S->buflen, 0, (word)(2 * BLAKE2B_BLOCKBYTES - S->buflen) );
         /* Padding */
  blake2b_compress( S, S->buf );

  for( i = 0; i < 8; ++i ) /* Output full hash to temp buffer */
    store64( buffer + sizeof( S->h[i] ) * i, S->h[i] );

  XMEMCPY( out, buffer, outlen );
  return 0;
}

/* inlen, at least, should be word64. Others can be size_t. */
int blake2b( byte *out, const void *in, const void *key, const byte outlen,
             const word64 inlen, byte keylen )
{
  blake2b_state S[1];

  /* Verify parameters */
  if ( NULL == in ) return -1;

  if ( NULL == out ) return -1;

  if( NULL == key ) keylen = 0;

  if( keylen > 0 )
  {
    if( blake2b_init_key( S, outlen, key, keylen ) < 0 ) return -1;
  }
  else
  {
    if( blake2b_init( S, outlen ) < 0 ) return -1;
  }

  blake2b_update( S, ( byte * )in, inlen );
  blake2b_final( S, out, outlen );
  return 0;
}

#if defined(BLAKE2B_SELFTEST)
#include <string.h>
#include "blake2-kat.h"
int main( int argc, char **argv )
{
  byte key[BLAKE2B_KEYBYTES];
  byte buf[KAT_LENGTH];

  for( word32 i = 0; i < BLAKE2B_KEYBYTES; ++i )
    key[i] = ( byte )i;

  for( word32 i = 0; i < KAT_LENGTH; ++i )
    buf[i] = ( byte )i;

  for( word32 i = 0; i < KAT_LENGTH; ++i )
  {
    byte hash[BLAKE2B_OUTBYTES];
    blake2b( hash, buf, key, BLAKE2B_OUTBYTES, i, BLAKE2B_KEYBYTES );

    if( 0 != memcmp( hash, blake2b_keyed_kat[i], BLAKE2B_OUTBYTES ) )
    {
      puts( "error" );
      return -1;
    }
  }

  puts( "ok" );
  return 0;
}
#endif


/* CTaoCrypt API */

/* Init Blake2b digest, track size incase final doesn't want to "remember" */
int InitBlake2b(Blake2b* b2b, word32 digestSz)
{
    b2b->digestSz = digestSz;

    return blake2b_init(b2b->S, (byte)digestSz);
}


/* Blake2b Update */
int Blake2bUpdate(Blake2b* b2b, const byte* data, word32 sz)
{
    return blake2b_update(b2b->S, data, sz);
}


/* Blake2b Final, if pass in zero size we use init digestSz */
int Blake2bFinal(Blake2b* b2b, byte* final, word32 requestSz)
{
    word32 sz = requestSz ? requestSz : b2b->digestSz;

    return blake2b_final(b2b->S, final, (byte)sz);
}


/* end CTaoCrypt API */

#endif  /* HAVE_BLAKE2 */

