sodium-javascript/index.js

'use strict';

// Based on https://github.com/dchest/tweetnacl-js/blob/6dcbcaf5f5cbfd313f2dcfe763db35c828c8ff5b/nacl-fast.js.

var sodium = module.exports

// Ported in 2014 by Dmitry Chestnykh and Devi Mandiri.
// Public domain.
//
// Implementation derived from TweetNaCl version 20140427.
// See for details: http://tweetnacl.cr.yp.to/

// also forwarded at the bottom but randombytes is non-enumerable
var randombytes = require('./randombytes').randombytes

function vn(x, xi, y, yi, n) {
  var i,d = 0;
  for (i = 0; i < n; i++) d |= x[xi+i]^y[yi+i];
  return (1 & ((d - 1) >>> 8)) - 1;
}

function crypto_verify_16(x, xi, y, yi) {
  return vn(x,xi,y,yi,16);
}


function crypto_stream_xor (c, cpos, m, mpos, clen, n, k) {
  cs.crypto_stream_xor(c, m, n, k)
}

function crypto_stream (c, cpos, clen, n, k) {
  cs.crypto_stream(c, n, k)
}

function crypto_onetimeauth(out, outpos, m, mpos, n, k) {
  var s = new poly1305(k);
  s.update(m, mpos, n);
  s.finish(out, outpos);
  return 0;
}

function crypto_onetimeauth_verify(h, hpos, m, mpos, n, k) {
  var x = new Uint8Array(16);
  crypto_onetimeauth(x,0,m,mpos,n,k);
  return crypto_verify_16(h,hpos,x,0);
}

function crypto_secretbox(c,m,d,n,k) {
  var i;
  if (d < 32) return -1;
  crypto_stream_xor(c,0,m,0,d,n,k);
  crypto_onetimeauth(c, 16, c, 32, d - 32, c);
  for (i = 0; i < 16; i++) c[i] = 0;
  return 0;
}

function crypto_secretbox_open(m,c,d,n,k) {
  var i;
  var x = new Uint8Array(32);
  if (d < 32) return -1;
  crypto_stream(x,0,32,n,k);
  if (crypto_onetimeauth_verify(c, 16,c, 32,d - 32,x) !== 0) return -1;
  crypto_stream_xor(m,0,c,0,d,n,k);
  for (i = 0; i < 32; i++) m[i] = 0;
  return 0;
}
function pow2523(o, i) {
  var c = gf();
  var a;
  for (a = 0; a < 16; a++) c[a] = i[a];
  for (a = 250; a >= 0; a--) {
      S(c, c);
      if(a !== 1) M(c, c, i);
  }
  for (a = 0; a < 16; a++) o[a] = c[a];
}


var K = [
  0x428a2f98, 0xd728ae22, 0x71374491, 0x23ef65cd,
  0xb5c0fbcf, 0xec4d3b2f, 0xe9b5dba5, 0x8189dbbc,
  0x3956c25b, 0xf348b538, 0x59f111f1, 0xb605d019,
  0x923f82a4, 0xaf194f9b, 0xab1c5ed5, 0xda6d8118,
  0xd807aa98, 0xa3030242, 0x12835b01, 0x45706fbe,
  0x243185be, 0x4ee4b28c, 0x550c7dc3, 0xd5ffb4e2,
  0x72be5d74, 0xf27b896f, 0x80deb1fe, 0x3b1696b1,
  0x9bdc06a7, 0x25c71235, 0xc19bf174, 0xcf692694,
  0xe49b69c1, 0x9ef14ad2, 0xefbe4786, 0x384f25e3,
  0x0fc19dc6, 0x8b8cd5b5, 0x240ca1cc, 0x77ac9c65,
  0x2de92c6f, 0x592b0275, 0x4a7484aa, 0x6ea6e483,
  0x5cb0a9dc, 0xbd41fbd4, 0x76f988da, 0x831153b5,
  0x983e5152, 0xee66dfab, 0xa831c66d, 0x2db43210,
  0xb00327c8, 0x98fb213f, 0xbf597fc7, 0xbeef0ee4,
  0xc6e00bf3, 0x3da88fc2, 0xd5a79147, 0x930aa725,
  0x06ca6351, 0xe003826f, 0x14292967, 0x0a0e6e70,
  0x27b70a85, 0x46d22ffc, 0x2e1b2138, 0x5c26c926,
  0x4d2c6dfc, 0x5ac42aed, 0x53380d13, 0x9d95b3df,
  0x650a7354, 0x8baf63de, 0x766a0abb, 0x3c77b2a8,
  0x81c2c92e, 0x47edaee6, 0x92722c85, 0x1482353b,
  0xa2bfe8a1, 0x4cf10364, 0xa81a664b, 0xbc423001,
  0xc24b8b70, 0xd0f89791, 0xc76c51a3, 0x0654be30,
  0xd192e819, 0xd6ef5218, 0xd6990624, 0x5565a910,
  0xf40e3585, 0x5771202a, 0x106aa070, 0x32bbd1b8,
  0x19a4c116, 0xb8d2d0c8, 0x1e376c08, 0x5141ab53,
  0x2748774c, 0xdf8eeb99, 0x34b0bcb5, 0xe19b48a8,
  0x391c0cb3, 0xc5c95a63, 0x4ed8aa4a, 0xe3418acb,
  0x5b9cca4f, 0x7763e373, 0x682e6ff3, 0xd6b2b8a3,
  0x748f82ee, 0x5defb2fc, 0x78a5636f, 0x43172f60,
  0x84c87814, 0xa1f0ab72, 0x8cc70208, 0x1a6439ec,
  0x90befffa, 0x23631e28, 0xa4506ceb, 0xde82bde9,
  0xbef9a3f7, 0xb2c67915, 0xc67178f2, 0xe372532b,
  0xca273ece, 0xea26619c, 0xd186b8c7, 0x21c0c207,
  0xeada7dd6, 0xcde0eb1e, 0xf57d4f7f, 0xee6ed178,
  0x06f067aa, 0x72176fba, 0x0a637dc5, 0xa2c898a6,
  0x113f9804, 0xbef90dae, 0x1b710b35, 0x131c471b,
  0x28db77f5, 0x23047d84, 0x32caab7b, 0x40c72493,
  0x3c9ebe0a, 0x15c9bebc, 0x431d67c4, 0x9c100d4c,
  0x4cc5d4be, 0xcb3e42b6, 0x597f299c, 0xfc657e2a,
  0x5fcb6fab, 0x3ad6faec, 0x6c44198c, 0x4a475817
];

function crypto_hashblocks_hl(hh, hl, m, n) {
  var wh = new Int32Array(16), wl = new Int32Array(16),
      bh0, bh1, bh2, bh3, bh4, bh5, bh6, bh7,
      bl0, bl1, bl2, bl3, bl4, bl5, bl6, bl7,
      th, tl, i, j, h, l, a, b, c, d;

  var ah0 = hh[0],
      ah1 = hh[1],
      ah2 = hh[2],
      ah3 = hh[3],
      ah4 = hh[4],
      ah5 = hh[5],
      ah6 = hh[6],
      ah7 = hh[7],

      al0 = hl[0],
      al1 = hl[1],
      al2 = hl[2],
      al3 = hl[3],
      al4 = hl[4],
      al5 = hl[5],
      al6 = hl[6],
      al7 = hl[7];

  var pos = 0;
  while (n >= 128) {
    for (i = 0; i < 16; i++) {
      j = 8 * i + pos;
      wh[i] = (m[j+0] << 24) | (m[j+1] << 16) | (m[j+2] << 8) | m[j+3];
      wl[i] = (m[j+4] << 24) | (m[j+5] << 16) | (m[j+6] << 8) | m[j+7];
    }
    for (i = 0; i < 80; i++) {
      bh0 = ah0;
      bh1 = ah1;
      bh2 = ah2;
      bh3 = ah3;
      bh4 = ah4;
      bh5 = ah5;
      bh6 = ah6;
      bh7 = ah7;

      bl0 = al0;
      bl1 = al1;
      bl2 = al2;
      bl3 = al3;
      bl4 = al4;
      bl5 = al5;
      bl6 = al6;
      bl7 = al7;

      // add
      h = ah7;
      l = al7;

      a = l & 0xffff; b = l >>> 16;
      c = h & 0xffff; d = h >>> 16;

      // Sigma1
      h = ((ah4 >>> 14) | (al4 << (32-14))) ^ ((ah4 >>> 18) | (al4 << (32-18))) ^ ((al4 >>> (41-32)) | (ah4 << (32-(41-32))));
      l = ((al4 >>> 14) | (ah4 << (32-14))) ^ ((al4 >>> 18) | (ah4 << (32-18))) ^ ((ah4 >>> (41-32)) | (al4 << (32-(41-32))));

      a += l & 0xffff; b += l >>> 16;
      c += h & 0xffff; d += h >>> 16;

      // Ch
      h = (ah4 & ah5) ^ (~ah4 & ah6);
      l = (al4 & al5) ^ (~al4 & al6);

      a += l & 0xffff; b += l >>> 16;
      c += h & 0xffff; d += h >>> 16;

      // K
      h = K[i*2];
      l = K[i*2+1];

      a += l & 0xffff; b += l >>> 16;
      c += h & 0xffff; d += h >>> 16;

      // w
      h = wh[i%16];
      l = wl[i%16];

      a += l & 0xffff; b += l >>> 16;
      c += h & 0xffff; d += h >>> 16;

      b += a >>> 16;
      c += b >>> 16;
      d += c >>> 16;

      th = c & 0xffff | d << 16;
      tl = a & 0xffff | b << 16;

      // add
      h = th;
      l = tl;

      a = l & 0xffff; b = l >>> 16;
      c = h & 0xffff; d = h >>> 16;

      // Sigma0
      h = ((ah0 >>> 28) | (al0 << (32-28))) ^ ((al0 >>> (34-32)) | (ah0 << (32-(34-32)))) ^ ((al0 >>> (39-32)) | (ah0 << (32-(39-32))));
      l = ((al0 >>> 28) | (ah0 << (32-28))) ^ ((ah0 >>> (34-32)) | (al0 << (32-(34-32)))) ^ ((ah0 >>> (39-32)) | (al0 << (32-(39-32))));

      a += l & 0xffff; b += l >>> 16;
      c += h & 0xffff; d += h >>> 16;

      // Maj
      h = (ah0 & ah1) ^ (ah0 & ah2) ^ (ah1 & ah2);
      l = (al0 & al1) ^ (al0 & al2) ^ (al1 & al2);

      a += l & 0xffff; b += l >>> 16;
      c += h & 0xffff; d += h >>> 16;

      b += a >>> 16;
      c += b >>> 16;
      d += c >>> 16;

      bh7 = (c & 0xffff) | (d << 16);
      bl7 = (a & 0xffff) | (b << 16);

      // add
      h = bh3;
      l = bl3;

      a = l & 0xffff; b = l >>> 16;
      c = h & 0xffff; d = h >>> 16;

      h = th;
      l = tl;

      a += l & 0xffff; b += l >>> 16;
      c += h & 0xffff; d += h >>> 16;

      b += a >>> 16;
      c += b >>> 16;
      d += c >>> 16;

      bh3 = (c & 0xffff) | (d << 16);
      bl3 = (a & 0xffff) | (b << 16);

      ah1 = bh0;
      ah2 = bh1;
      ah3 = bh2;
      ah4 = bh3;
      ah5 = bh4;
      ah6 = bh5;
      ah7 = bh6;
      ah0 = bh7;

      al1 = bl0;
      al2 = bl1;
      al3 = bl2;
      al4 = bl3;
      al5 = bl4;
      al6 = bl5;
      al7 = bl6;
      al0 = bl7;

      if (i%16 === 15) {
        for (j = 0; j < 16; j++) {
          // add
          h = wh[j];
          l = wl[j];

          a = l & 0xffff; b = l >>> 16;
          c = h & 0xffff; d = h >>> 16;

          h = wh[(j+9)%16];
          l = wl[(j+9)%16];

          a += l & 0xffff; b += l >>> 16;
          c += h & 0xffff; d += h >>> 16;

          // sigma0
          th = wh[(j+1)%16];
          tl = wl[(j+1)%16];
          h = ((th >>> 1) | (tl << (32-1))) ^ ((th >>> 8) | (tl << (32-8))) ^ (th >>> 7);
          l = ((tl >>> 1) | (th << (32-1))) ^ ((tl >>> 8) | (th << (32-8))) ^ ((tl >>> 7) | (th << (32-7)));

          a += l & 0xffff; b += l >>> 16;
          c += h & 0xffff; d += h >>> 16;

          // sigma1
          th = wh[(j+14)%16];
          tl = wl[(j+14)%16];
          h = ((th >>> 19) | (tl << (32-19))) ^ ((tl >>> (61-32)) | (th << (32-(61-32)))) ^ (th >>> 6);
          l = ((tl >>> 19) | (th << (32-19))) ^ ((th >>> (61-32)) | (tl << (32-(61-32)))) ^ ((tl >>> 6) | (th << (32-6)));

          a += l & 0xffff; b += l >>> 16;
          c += h & 0xffff; d += h >>> 16;

          b += a >>> 16;
          c += b >>> 16;
          d += c >>> 16;

          wh[j] = (c & 0xffff) | (d << 16);
          wl[j] = (a & 0xffff) | (b << 16);
        }
      }
    }

    // add
    h = ah0;
    l = al0;

    a = l & 0xffff; b = l >>> 16;
    c = h & 0xffff; d = h >>> 16;

    h = hh[0];
    l = hl[0];

    a += l & 0xffff; b += l >>> 16;
    c += h & 0xffff; d += h >>> 16;

    b += a >>> 16;
    c += b >>> 16;
    d += c >>> 16;

    hh[0] = ah0 = (c & 0xffff) | (d << 16);
    hl[0] = al0 = (a & 0xffff) | (b << 16);

    h = ah1;
    l = al1;

    a = l & 0xffff; b = l >>> 16;
    c = h & 0xffff; d = h >>> 16;

    h = hh[1];
    l = hl[1];

    a += l & 0xffff; b += l >>> 16;
    c += h & 0xffff; d += h >>> 16;

    b += a >>> 16;
    c += b >>> 16;
    d += c >>> 16;

    hh[1] = ah1 = (c & 0xffff) | (d << 16);
    hl[1] = al1 = (a & 0xffff) | (b << 16);

    h = ah2;
    l = al2;

    a = l & 0xffff; b = l >>> 16;
    c = h & 0xffff; d = h >>> 16;

    h = hh[2];
    l = hl[2];

    a += l & 0xffff; b += l >>> 16;
    c += h & 0xffff; d += h >>> 16;

    b += a >>> 16;
    c += b >>> 16;
    d += c >>> 16;

    hh[2] = ah2 = (c & 0xffff) | (d << 16);
    hl[2] = al2 = (a & 0xffff) | (b << 16);

    h = ah3;
    l = al3;

    a = l & 0xffff; b = l >>> 16;
    c = h & 0xffff; d = h >>> 16;

    h = hh[3];
    l = hl[3];

    a += l & 0xffff; b += l >>> 16;
    c += h & 0xffff; d += h >>> 16;

    b += a >>> 16;
    c += b >>> 16;
    d += c >>> 16;

    hh[3] = ah3 = (c & 0xffff) | (d << 16);
    hl[3] = al3 = (a & 0xffff) | (b << 16);

    h = ah4;
    l = al4;

    a = l & 0xffff; b = l >>> 16;
    c = h & 0xffff; d = h >>> 16;

    h = hh[4];
    l = hl[4];

    a += l & 0xffff; b += l >>> 16;
    c += h & 0xffff; d += h >>> 16;

    b += a >>> 16;
    c += b >>> 16;
    d += c >>> 16;

    hh[4] = ah4 = (c & 0xffff) | (d << 16);
    hl[4] = al4 = (a & 0xffff) | (b << 16);

    h = ah5;
    l = al5;

    a = l & 0xffff; b = l >>> 16;
    c = h & 0xffff; d = h >>> 16;

    h = hh[5];
    l = hl[5];

    a += l & 0xffff; b += l >>> 16;
    c += h & 0xffff; d += h >>> 16;

    b += a >>> 16;
    c += b >>> 16;
    d += c >>> 16;

    hh[5] = ah5 = (c & 0xffff) | (d << 16);
    hl[5] = al5 = (a & 0xffff) | (b << 16);

    h = ah6;
    l = al6;

    a = l & 0xffff; b = l >>> 16;
    c = h & 0xffff; d = h >>> 16;

    h = hh[6];
    l = hl[6];

    a += l & 0xffff; b += l >>> 16;
    c += h & 0xffff; d += h >>> 16;

    b += a >>> 16;
    c += b >>> 16;
    d += c >>> 16;

    hh[6] = ah6 = (c & 0xffff) | (d << 16);
    hl[6] = al6 = (a & 0xffff) | (b << 16);

    h = ah7;
    l = al7;

    a = l & 0xffff; b = l >>> 16;
    c = h & 0xffff; d = h >>> 16;

    h = hh[7];
    l = hl[7];

    a += l & 0xffff; b += l >>> 16;
    c += h & 0xffff; d += h >>> 16;

    b += a >>> 16;
    c += b >>> 16;
    d += c >>> 16;

    hh[7] = ah7 = (c & 0xffff) | (d << 16);
    hl[7] = al7 = (a & 0xffff) | (b << 16);

    pos += 128;
    n -= 128;
  }

  return n;
}

function crypto_hash(out, m, n) {
  var hh = new Int32Array(8),
      hl = new Int32Array(8),
      x = new Uint8Array(256),
      i, b = n;

  hh[0] = 0x6a09e667;
  hh[1] = 0xbb67ae85;
  hh[2] = 0x3c6ef372;
  hh[3] = 0xa54ff53a;
  hh[4] = 0x510e527f;
  hh[5] = 0x9b05688c;
  hh[6] = 0x1f83d9ab;
  hh[7] = 0x5be0cd19;

  hl[0] = 0xf3bcc908;
  hl[1] = 0x84caa73b;
  hl[2] = 0xfe94f82b;
  hl[3] = 0x5f1d36f1;
  hl[4] = 0xade682d1;
  hl[5] = 0x2b3e6c1f;
  hl[6] = 0xfb41bd6b;
  hl[7] = 0x137e2179;

  crypto_hashblocks_hl(hh, hl, m, n);
  n %= 128;

  for (i = 0; i < n; i++) x[i] = m[b-n+i];
  x[n] = 128;

  n = 256-128*(n<112?1:0);
  x[n-9] = 0;
  ts64(x, n-8,  (b / 0x20000000) | 0, b << 3);
  crypto_hashblocks_hl(hh, hl, x, n);

  for (i = 0; i < 8; i++) ts64(out, 8*i, hh[i], hl[i]);

  return 0;
}

function add(p, q) {
  var a = gf(), b = gf(), c = gf(),
      d = gf(), e = gf(), f = gf(),
      g = gf(), h = gf(), t = gf();

  Z(a, p[1], p[0]);
  Z(t, q[1], q[0]);
  M(a, a, t);
  A(b, p[0], p[1]);
  A(t, q[0], q[1]);
  M(b, b, t);
  M(c, p[3], q[3]);
  M(c, c, D2);
  M(d, p[2], q[2]);
  A(d, d, d);
  Z(e, b, a);
  Z(f, d, c);
  A(g, d, c);
  A(h, b, a);

  M(p[0], e, f);
  M(p[1], h, g);
  M(p[2], g, f);
  M(p[3], e, h);
}

function cswap(p, q, b) {
  var i;
  for (i = 0; i < 4; i++) {
    sel25519(p[i], q[i], b);
  }
}

function pack(r, p) {
  var tx = gf(), ty = gf(), zi = gf();
  inv25519(zi, p[2]);
  M(tx, p[0], zi);
  M(ty, p[1], zi);
  pack25519(r, ty);
  r[31] ^= par25519(tx) << 7;
}

function scalarmult(p, q, s) {
  var b, i;
  set25519(p[0], gf0);
  set25519(p[1], gf1);
  set25519(p[2], gf1);
  set25519(p[3], gf0);
  for (i = 255; i >= 0; --i) {
    b = (s[(i/8)|0] >> (i&7)) & 1;
    cswap(p, q, b);
    add(q, p);
    add(p, p);
    cswap(p, q, b);
  }
}

function scalarbase(p, s) {
  var q = [gf(), gf(), gf(), gf()];
  set25519(q[0], X);
  set25519(q[1], Y);
  set25519(q[2], gf1);
  M(q[3], X, Y);
  scalarmult(p, q, s);
}

function crypto_sign_keypair(pk, sk, seeded) {
  check(pk, sodium.crypto_sign_PUBLICKEYBYTES)
  check(sk, sodium.crypto_sign_SECRETKEYBYTES)

  var d = new Uint8Array(64);
  var p = [gf(), gf(), gf(), gf()];
  var i;

  if (!seeded) randombytes(sk, 32);
  crypto_hash(d, sk, 32);
  d[0] &= 248;
  d[31] &= 127;
  d[31] |= 64;

  scalarbase(p, d);
  pack(pk, p);

  for (i = 0; i < 32; i++) sk[i+32] = pk[i];
  return 0;
}

function crypto_sign_seed_keypair (pk, sk, seed) {
  check(seed, sodium.crypto_sign_SEEDBYTES)
  seed.copy(sk)
  crypto_sign_keypair(pk, sk, true)
}

var L = new Float64Array([0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x10]);

function modL(r, x) {
  var carry, i, j, k;
  for (i = 63; i >= 32; --i) {
    carry = 0;
    for (j = i - 32, k = i - 12; j < k; ++j) {
      x[j] += carry - 16 * x[i] * L[j - (i - 32)];
      carry = (x[j] + 128) >> 8;
      x[j] -= carry * 256;
    }
    x[j] += carry;
    x[i] = 0;
  }
  carry = 0;
  for (j = 0; j < 32; j++) {
    x[j] += carry - (x[31] >> 4) * L[j];
    carry = x[j] >> 8;
    x[j] &= 255;
  }
  for (j = 0; j < 32; j++) x[j] -= carry * L[j];
  for (i = 0; i < 32; i++) {
    x[i+1] += x[i] >> 8;
    r[i] = x[i] & 255;
  }
}

function reduce(r) {
  var x = new Float64Array(64), i;
  for (i = 0; i < 64; i++) x[i] = r[i];
  for (i = 0; i < 64; i++) r[i] = 0;
  modL(r, x);
}

// Note: difference from C - smlen returned, not passed as argument.
function crypto_sign(sm, m, sk) {
  check(sm, crypto_sign_BYTES + m.length)
  check(m, 0)
  check(sk, crypto_sign_SECRETKEYBYTES)
  var n = m.length

  var d = new Uint8Array(64), h = new Uint8Array(64), r = new Uint8Array(64);
  var i, j, x = new Float64Array(64);
  var p = [gf(), gf(), gf(), gf()];

  crypto_hash(d, sk, 32);
  d[0] &= 248;
  d[31] &= 127;
  d[31] |= 64;

  var smlen = n + 64;
  for (i = 0; i < n; i++) sm[64 + i] = m[i];
  for (i = 0; i < 32; i++) sm[32 + i] = d[32 + i];

  crypto_hash(r, sm.subarray(32), n+32);
  reduce(r);
  scalarbase(p, r);
  pack(sm, p);

  for (i = 32; i < 64; i++) sm[i] = sk[i];
  crypto_hash(h, sm, n + 64);
  reduce(h);

  for (i = 0; i < 64; i++) x[i] = 0;
  for (i = 0; i < 32; i++) x[i] = r[i];
  for (i = 0; i < 32; i++) {
    for (j = 0; j < 32; j++) {
      x[i+j] += h[i] * d[j];
    }
  }

  modL(sm.subarray(32), x);
}

function crypto_sign_detached(sig, m, sk) {
  var sm = new Uint8Array(m.length + crypto_sign_BYTES)
  crypto_sign(sm, m, sk)
  for (var i = 0; i < crypto_sign_BYTES; i++) sig[i] = sm[i]
}

function unpackneg(r, p) {
  var t = gf(), chk = gf(), num = gf(),
      den = gf(), den2 = gf(), den4 = gf(),
      den6 = gf();

  set25519(r[2], gf1);
  unpack25519(r[1], p);
  S(num, r[1]);
  M(den, num, D);
  Z(num, num, r[2]);
  A(den, r[2], den);

  S(den2, den);
  S(den4, den2);
  M(den6, den4, den2);
  M(t, den6, num);
  M(t, t, den);

  pow2523(t, t);
  M(t, t, num);
  M(t, t, den);
  M(t, t, den);
  M(r[0], t, den);

  S(chk, r[0]);
  M(chk, chk, den);
  if (neq25519(chk, num)) M(r[0], r[0], I);

  S(chk, r[0]);
  M(chk, chk, den);
  if (neq25519(chk, num)) return -1;

  if (par25519(r[0]) === (p[31]>>7)) Z(r[0], gf0, r[0]);

  M(r[3], r[0], r[1]);
  return 0;
}

function crypto_sign_open(msg, sm, pk) {
  check(msg, sm.length - crypto_sign_BYTES)
  check(sm, crypto_sign_BYTES)
  check(pk, crypto_sign_PUBLICKEYBYTES)
  var n = sm.length
  var m = new Uint8Array(sm.length)

  var i, mlen;
  var t = new Uint8Array(32), h = new Uint8Array(64);
  var p = [gf(), gf(), gf(), gf()],
      q = [gf(), gf(), gf(), gf()];

  mlen = -1;
  if (n < 64) return false;

  if (unpackneg(q, pk)) return false;

  for (i = 0; i < n; i++) m[i] = sm[i];
  for (i = 0; i < 32; i++) m[i+32] = pk[i];
  crypto_hash(h, m, n);
  reduce(h);
  scalarmult(p, q, h);

  scalarbase(q, sm.subarray(32));
  add(p, q);
  pack(t, p);

  n -= 64;
  if (crypto_verify_32(sm, 0, t, 0)) {
    for (i = 0; i < n; i++) m[i] = 0;
    return false;
  }

  for (i = 0; i < n; i++) msg[i] = sm[i + 64];
  mlen = n;
  return true;
}

function crypto_sign_verify_detached (sig, m, pk) {
  check(sig, crypto_sign_BYTES)
  var sm = new Uint8Array(m.length + crypto_sign_BYTES)
  var i = 0
  for (i = 0; i < crypto_sign_BYTES; i++) sm[i] = sig[i]
  for (i = 0; i < m.length; i++) sm[i + crypto_sign_BYTES] = m[i]
  return crypto_sign_open(m, sm, pk)
}

function crypto_secretbox_detached (o, mac, msg, n, k) {
  check(mac, sodium.crypto_secretbox_MACBYTES)
  var tmp = new Uint8Array(msg.length + mac.length)
  crypto_secretbox_easy(tmp, msg, n, k)
  o.set(tmp.subarray(0, msg.length))
  mac.set(tmp.subarray(msg.length))
}

function crypto_secretbox_open_detached (msg, o, mac, n, k) {
  check(mac, sodium.crypto_secretbox_MACBYTES)
  var tmp = new Uint8Array(o.length + mac.length)
  tmp.set(o)
  tmp.set(mac, msg.length)
  return crypto_secretbox_open_easy(msg, tmp, n, k)
}

function crypto_secretbox_easy(o, msg, n, k) {
  check(msg, 0)
  check(o, msg.length + sodium.crypto_secretbox_MACBYTES)
  check(n, crypto_secretbox_NONCEBYTES)
  check(k, crypto_secretbox_KEYBYTES)

  var i
  var m = new Uint8Array(crypto_secretbox_ZEROBYTES + msg.length);
  var c = new Uint8Array(m.length);
  for (i = 0; i < msg.length; i++) m[i+crypto_secretbox_ZEROBYTES] = msg[i];
  crypto_secretbox(c, m, m.length, n, k);
  for (i = crypto_secretbox_BOXZEROBYTES; i < c.length; i++) o[i - crypto_secretbox_BOXZEROBYTES] = c[i]
}

function crypto_secretbox_open_easy(msg, box, n, k) {
  check(box, sodium.crypto_secretbox_MACBYTES)
  check(msg, box.length - sodium.crypto_secretbox_MACBYTES)
  check(n, crypto_secretbox_NONCEBYTES)
  check(k, crypto_secretbox_KEYBYTES)

  var i
  var c = new Uint8Array(crypto_secretbox_BOXZEROBYTES + box.length);
  var m = new Uint8Array(c.length);
  for (i = 0; i < box.length; i++) c[i+crypto_secretbox_BOXZEROBYTES] = box[i];
  if (c.length < 32) return false;
  if (crypto_secretbox_open(m, c, c.length, n, k) !== 0) return false;

  for (i = crypto_secretbox_ZEROBYTES; i < m.length; i++) msg[i - crypto_secretbox_ZEROBYTES] = m[i]
  return true
}

function crypto_box_keypair(pk, sk) {
  check(pk, crypto_box_PUBLICKEYBYTES)
  check(sk, crypto_box_SECRETKEYBYTES)
  randombytes(sk, 32)
  return crypto_scalarmult_base(pk, sk)
}

function crypto_box_seal(c, m, pk) {
  check(c, crypto_box_SEALBYTES + m.length)
  check(pk, crypto_box_PUBLICKEYBYTES)

  var epk = c.subarray(0, crypto_box_PUBLICKEYBYTES)
  var esk = new Uint8Array(crypto_box_SECRETKEYBYTES)
  crypto_box_keypair(epk, esk)

  var n = new Uint8Array(crypto_box_NONCEBYTES)
  sodium.crypto_generichash_batch(n, [ epk, pk ])

  var s = new Uint8Array(crypto_box_PUBLICKEYBYTES)
  crypto_scalarmult(s, esk, pk)

  var k = new Uint8Array(crypto_box_BEFORENMBYTES)
  var zero = new Uint8Array(16)
  xsalsa20.core_hsalsa20(k, zero, s, xsalsa20.SIGMA)

  crypto_secretbox_easy(c.subarray(epk.length), m, n, k)

  cleanup(esk)
}

function crypto_box_seal_open(m, c, pk, sk) {
  check(c, crypto_box_SEALBYTES)
  check(m, c.length - crypto_box_SEALBYTES)
  check(pk, crypto_box_PUBLICKEYBYTES)
  check(sk, crypto_box_SECRETKEYBYTES)

  var epk = c.subarray(0, crypto_box_PUBLICKEYBYTES)

  var n = new Uint8Array(crypto_box_NONCEBYTES)
  sodium.crypto_generichash_batch(n, [ epk, pk ])

  var s = new Uint8Array(crypto_box_PUBLICKEYBYTES)
  crypto_scalarmult(s, sk, epk)

  var k = new Uint8Array(crypto_box_BEFORENMBYTES)
  var zero = new Uint8Array(16)
  xsalsa20.core_hsalsa20(k, zero, s, xsalsa20.SIGMA)

  return crypto_secretbox_open_easy(m, c.subarray(epk.length), n, k)
}

var crypto_secretbox_KEYBYTES = 32,
    crypto_secretbox_NONCEBYTES = 24,
    crypto_secretbox_ZEROBYTES = 32,
    crypto_secretbox_BOXZEROBYTES = 16,
    crypto_box_PUBLICKEYBYTES = 32,
    crypto_box_SECRETKEYBYTES = 32,
    crypto_box_BEFORENMBYTES = 32,
    crypto_box_NONCEBYTES = crypto_secretbox_NONCEBYTES,
    crypto_box_ZEROBYTES = crypto_secretbox_ZEROBYTES,
    crypto_box_BOXZEROBYTES = crypto_secretbox_BOXZEROBYTES,
    crypto_box_SEALBYTES = 48,
    crypto_box_BEFORENMBYTES = 32,
    crypto_sign_BYTES = 64,
    crypto_sign_PUBLICKEYBYTES = 32,
    crypto_sign_SECRETKEYBYTES = 64,
    crypto_sign_SEEDBYTES = 32,
    crypto_hash_BYTES = 64;

sodium.memzero = function (len, offset) {
  for (var i = offset; i < len; i++) arr[i] = 0;
}

sodium.crypto_sign_BYTES = crypto_sign_BYTES
sodium.crypto_sign_PUBLICKEYBYTES = crypto_sign_PUBLICKEYBYTES
sodium.crypto_sign_SECRETKEYBYTES = crypto_sign_SECRETKEYBYTES
sodium.crypto_sign_SEEDBYTES = crypto_sign_SEEDBYTES
sodium.crypto_sign_keypair = crypto_sign_keypair
sodium.crypto_sign_seed_keypair = crypto_sign_seed_keypair
sodium.crypto_sign = crypto_sign
sodium.crypto_sign_open = crypto_sign_open
sodium.crypto_sign_detached = crypto_sign_detached
sodium.crypto_sign_verify_detached = crypto_sign_verify_detached

forward(require('./crypto_generichash'))
forward(require('./crypto_kdf'))
forward(require('./crypto_shorthash'))
forward(require('./randombytes'))
forward(require('./crypto_stream'))


sodium.crypto_secretbox_KEYBYTES = crypto_secretbox_KEYBYTES,
sodium.crypto_secretbox_NONCEBYTES = crypto_secretbox_NONCEBYTES,
sodium.crypto_secretbox_MACBYTES = 16
sodium.crypto_secretbox_easy = crypto_secretbox_easy
sodium.crypto_secretbox_open_easy = crypto_secretbox_open_easy
sodium.crypto_secretbox_detached = crypto_secretbox_detached
sodium.crypto_secretbox_open_detached = crypto_secretbox_open_detached

sodium.crypto_box_PUBLICKEYBYTES = crypto_box_PUBLICKEYBYTES
sodium.crypto_box_SECRETKEYBYTES = crypto_box_SECRETKEYBYTES
sodium.crypto_box_SEALBYTES = crypto_box_SEALBYTES
sodium.crypto_box_BEFORENMBYTES = crypto_box_BEFORENMBYTES
sodium.crypto_box_keypair = crypto_box_keypair
sodium.crypto_box_seal = crypto_box_seal
sodium.crypto_box_seal_open = crypto_box_seal_open

sodium.sodium_malloc = function (n) {
  return new Uint8Array(n)
}

function cleanup(arr) {
  for (var i = 0; i < arr.length; i++) arr[i] = 0;
}

forward(require('./crypto_scalarmult'))
forward(require('./crypto_stream'))

function forward (submodule) {
  Object.keys(submodule).forEach(function (prop) {
    module.exports[prop] = submodule[prop]
  })
}