/*
   BLAKE2 reference source code package - optimized C implementations

   Copyright 2012, Samuel Neves <sneves@dei.uc.pt>.  You may use this under the
   terms of the CC0, the OpenSSL Licence, or the Apache Public License 2.0, at
   your option.  The terms of these licenses can be found at:

   - CC0 1.0 Universal : http://creativecommons.org/publicdomain/zero/1.0
   - OpenSSL license   : https://www.openssl.org/source/license.html
   - Apache 2.0        : http://www.apache.org/licenses/LICENSE-2.0

   More information about the BLAKE2 hash function can be found at
   https://blake2.net.
*/

/* Adapted for VeraCrypt */

#include "blake2.h"
#include "Common/Endian.h"
#include "Crypto/config.h"
#include "Crypto/cpu.h"
#include "Crypto/misc.h"

// load32 is always called in SSE case which implies little endian 
#define load32(x)	*((uint32*) (x))

const uint32 blake2s_IV[8] =
{
  0x6A09E667UL, 0xBB67AE85UL, 0x3C6EF372UL, 0xA54FF53AUL,
  0x510E527FUL, 0x9B05688CUL, 0x1F83D9ABUL, 0x5BE0CD19UL
};

static const uint8 blake2s_sigma[10][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 } ,
};

/* Some helper functions */
#define blake2s_set_lastnode(S)  S->f[1] = (uint32)-1;

#define blake2s_is_lastblock(S)  (S->f[0] != 0)

#define blake2s_set_lastblock(S) { \
									if( S->last_node ) blake2s_set_lastnode( S ); \
									S->f[0] = (uint32)-1; \
								 }

#define blake2s_increment_counter(S,inc)	{ \
												uint64 t = ( (( uint64 )S->t[1]) << 32 ) | S->t[0]; \
												t += (inc); \
												S->t[0] = ( uint32 )( t       ); \
												S->t[1] = ( uint32 )( t >> 32 ); \
											}

/* init2 xors IV with input parameter block */
void blake2s_init_param( blake2s_state *S, const blake2s_param *P )
{
  size_t i;
  /*blake2s_init0( S ); */
  const uint8 * v = ( const uint8 * )( blake2s_IV );
  const uint8 * p = ( const uint8 * )( P );
  uint8 * h = ( uint8 * )( S->h );
  /* IV XOR ParamBlock */
  memset( S, 0, sizeof( blake2s_state ) );

  for( i = 0; i < BLAKE2S_OUTBYTES; ++i ) h[i] = v[i] ^ p[i];

  S->outlen = P->digest_length;
}


#define G(r,i,a,b,c,d)                      \
  do {                                      \
    a = a + b + m[blake2s_sigma[r][2*i+0]]; \
    d = rotr32(d ^ a, 16);                  \
    c = c + d;                              \
    b = rotr32(b ^ c, 12);                  \
    a = a + b + m[blake2s_sigma[r][2*i+1]]; \
    d = rotr32(d ^ a, 8);                   \
    c = c + d;                              \
    b = rotr32(b ^ c, 7);                   \
  } 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)

typedef void (*blake2s_compressFn)( blake2s_state *S, const uint8 block[BLAKE2S_BLOCKBYTES] );

blake2s_compressFn blake2s_compress_func = NULL;
#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32
extern int blake2s_has_sse2();
extern int blake2s_has_ssse3();
extern int blake2s_has_sse41();
extern void blake2s_compress_sse2( blake2s_state *S, const uint8 block[BLAKE2S_BLOCKBYTES] );
extern void blake2s_compress_ssse3( blake2s_state *S, const uint8 block[BLAKE2S_BLOCKBYTES] );
extern void blake2s_compress_sse41( blake2s_state *S, const uint8 block[BLAKE2S_BLOCKBYTES] );
#endif


static void blake2s_compress_std( blake2s_state *S, const uint8 in[BLAKE2S_BLOCKBYTES] )
{
  uint32 m[16];
  uint32 v[16];
  size_t i;

  for( i = 0; i < 16; ++i ) {
	m[i] = *((uint32*) (in + i * sizeof( m[i] )));
  }

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

  v[ 8] = blake2s_IV[0];
  v[ 9] = blake2s_IV[1];
  v[10] = blake2s_IV[2];
  v[11] = blake2s_IV[3];
  v[12] = S->t[0] ^ blake2s_IV[4];
  v[13] = S->t[1] ^ blake2s_IV[5];
  v[14] = S->f[0] ^ blake2s_IV[6];
  v[15] = S->f[1] ^ blake2s_IV[7];

  ROUND( 0 );
  ROUND( 1 );
  ROUND( 2 );
  ROUND( 3 );
  ROUND( 4 );
  ROUND( 5 );
  ROUND( 6 );
  ROUND( 7 );
  ROUND( 8 );
  ROUND( 9 );

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

#undef G
#undef ROUND


/* Some sort of default parameter block initialization, for sequential blake2s */
void blake2s_init( blake2s_state *S )
{
  blake2s_param P[1];

  P->digest_length = BLAKE2S_OUTBYTES;
  P->key_length    = 0;
  P->fanout        = 1;
  P->depth         = 1;
  P->leaf_length = 0;
  P->node_offset = 0;
  P->xof_length = 0;
  P->node_depth    = 0;
  P->inner_length  = 0;
  /* memset(P->reserved, 0, sizeof(P->reserved) ); */
  memset( P->salt,     0, sizeof( P->salt ) );
  memset( P->personal, 0, sizeof( P->personal ) );

  blake2s_init_param( S, P );

  if (!blake2s_compress_func)
  {
#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32
	if (HasSSE2() && blake2s_has_sse2())
	{
		if (HasSSE41() && blake2s_has_sse41())
		{
			blake2s_compress_func = blake2s_compress_sse41;
		}
		else
		if (HasSSSE3() && blake2s_has_ssse3())
		{
			blake2s_compress_func = blake2s_compress_ssse3;
		}
		else
            blake2s_compress_func = blake2s_compress_sse2;
	}
	else
#endif
	  blake2s_compress_func = blake2s_compress_std;
  }
}

void blake2s_update( blake2s_state *S, const void *pin, size_t inlen )
{
  const unsigned char * in = (const unsigned char *)pin;
  if( inlen > 0 )
  {
    size_t left = S->buflen;
    size_t fill = BLAKE2S_BLOCKBYTES - left;
    if( inlen > fill )
    {
      S->buflen = 0;
      memcpy( S->buf + left, in, fill ); /* Fill buffer */
      blake2s_increment_counter( S, BLAKE2S_BLOCKBYTES );
      blake2s_compress_func( S, S->buf ); /* Compress */
      in += fill; inlen -= fill;
      while(inlen > BLAKE2S_BLOCKBYTES) {
        blake2s_increment_counter(S, BLAKE2S_BLOCKBYTES);
        blake2s_compress_func( S, in );
        in += BLAKE2S_BLOCKBYTES;
        inlen -= BLAKE2S_BLOCKBYTES;
      }
    }
    memcpy( S->buf + S->buflen, in, inlen );
    S->buflen += inlen;
  }
}

int blake2s_final( blake2s_state *S, unsigned char *out )
{
  size_t i;

  if( blake2s_is_lastblock( S ) )
    return -1;

  blake2s_increment_counter( S, (uint32)S->buflen );
  blake2s_set_lastblock( S );
  memset( S->buf + S->buflen, 0, BLAKE2S_BLOCKBYTES - S->buflen ); /* Padding */
  blake2s_compress_func( S, S->buf );

  for( i = 0; i < 8; ++i ) /* Output full hash to temp buffer */
  {
#if BYTE_ORDER == LITTLE_ENDIAN
	*((uint32*) out) = S->h[i];
#else
	uint32 w = S->h[i] ;
	out[0] = (uint8)(w >>  0);
	out[1] = (uint8)(w >>  8);
	out[2] = (uint8)(w >> 16);
	out[3] = (uint8)(w >> 24);
#endif
	out += sizeof (uint32);
  }

  return 0;
}

/* inlen, at least, should be uint64. Others can be size_t. */
int blake2s( void *out, const void *in, size_t inlen)
{
  blake2s_state S[1];

  /* Verify parameters */
  if ( NULL == in && inlen > 0 ) return -1;

  if ( NULL == out ) return -1;

  blake2s_init( S );

  blake2s_update( S, ( const uint8 * )in, inlen );
  blake2s_final( S, (unsigned char*) out );
  return 0;
}

#if defined(SUPERCOP)
int crypto_hash( unsigned char *out, unsigned char *in, unsigned long long inlen )
{
  return blake2s( out, BLAKE2S_OUTBYTES, in, inlen, NULL, 0 );
}
#endif

#if defined(BLAKE2S_SELFTEST)
#include <string.h>
#include "blake2-kat.h"
int main( void )
{
  uint8 key[BLAKE2S_KEYBYTES];
  uint8 buf[BLAKE2_KAT_LENGTH];
  size_t i, step;

  for( i = 0; i < BLAKE2S_KEYBYTES; ++i )
    key[i] = ( uint8 )i;

  for( i = 0; i < BLAKE2_KAT_LENGTH; ++i )
    buf[i] = ( uint8 )i;

  /* Test simple API */
  for( i = 0; i < BLAKE2_KAT_LENGTH; ++i )
  {
    uint8 hash[BLAKE2S_OUTBYTES];
    blake2s( hash, BLAKE2S_OUTBYTES, buf, i, key, BLAKE2S_KEYBYTES );

    if( 0 != memcmp( hash, blake2s_keyed_kat[i], BLAKE2S_OUTBYTES ) )
    {
      goto fail;
    }
  }

  /* Test streaming API */
  for(step = 1; step < BLAKE2S_BLOCKBYTES; ++step) {
    for (i = 0; i < BLAKE2_KAT_LENGTH; ++i) {
      uint8 hash[BLAKE2S_OUTBYTES];
      blake2s_state S;
      uint8 * p = buf;
      size_t mlen = i;
      int err = 0;

      if( (err = blake2s_init_key(&S, BLAKE2S_OUTBYTES, key, BLAKE2S_KEYBYTES)) < 0 ) {
        goto fail;
      }

      while (mlen >= step) {
        if ( (err = blake2s_update(&S, p, step)) < 0 ) {
          goto fail;
        }
        mlen -= step;
        p += step;
      }
      if ( (err = blake2s_update(&S, p, mlen)) < 0) {
        goto fail;
      }
      if ( (err = blake2s_final(&S, hash, BLAKE2S_OUTBYTES)) < 0) {
        goto fail;
      }

      if (0 != memcmp(hash, blake2s_keyed_kat[i], BLAKE2S_OUTBYTES)) {
        goto fail;
      }
    }
  }

  puts( "ok" );
  return 0;
fail:
  puts("error");
  return -1;
}
#endif
