nacl-fast.js

(function(nacl) {
'use strict';

// 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/

var gf = function(init) {
  var i, r = new Float64Array(16);
  if (init) for (i = 0; i < init.length; i++) r[i] = init[i];
  return r;
};

//  Pluggable, initialized in high-level API below.
var randombytes = function(/* x, n */) { throw new Error('no PRNG'); };

var _0 = new Uint8Array(16);
var _9 = new Uint8Array(32); _9[0] = 9;

var gf0 = gf(),
    gf1 = gf([1]),
    _121665 = gf([0xdb41, 1]),
    D = gf([0x78a3, 0x1359, 0x4dca, 0x75eb, 0xd8ab, 0x4141, 0x0a4d, 0x0070, 0xe898, 0x7779, 0x4079, 0x8cc7, 0xfe73, 0x2b6f, 0x6cee, 0x5203]),
    D2 = gf([0xf159, 0x26b2, 0x9b94, 0xebd6, 0xb156, 0x8283, 0x149a, 0x00e0, 0xd130, 0xeef3, 0x80f2, 0x198e, 0xfce7, 0x56df, 0xd9dc, 0x2406]),
    X = gf([0xd51a, 0x8f25, 0x2d60, 0xc956, 0xa7b2, 0x9525, 0xc760, 0x692c, 0xdc5c, 0xfdd6, 0xe231, 0xc0a4, 0x53fe, 0xcd6e, 0x36d3, 0x2169]),
    Y = gf([0x6658, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666]),
    I = gf([0xa0b0, 0x4a0e, 0x1b27, 0xc4ee, 0xe478, 0xad2f, 0x1806, 0x2f43, 0xd7a7, 0x3dfb, 0x0099, 0x2b4d, 0xdf0b, 0x4fc1, 0x2480, 0x2b83]);

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_32(x, xi, y, yi) {
  return vn(x,xi,y,yi,32);
}


function set25519(r, a) {
  var i;
  for (i = 0; i < 16; i++) r[i] = a[i]|0;
}

function car25519(o) {
  var i, v, c = 1;
  for (i = 0; i < 16; i++) {
    v = o[i] + c + 65535;
    c = Math.floor(v / 65536);
    o[i] = v - c * 65536;
  }
  o[0] += c-1 + 37 * (c-1);
}

function sel25519(p, q, b) {
  var t, c = ~(b-1);
  for (var i = 0; i < 16; i++) {
    t = c & (p[i] ^ q[i]);
    p[i] ^= t;
    q[i] ^= t;
  }
}

function pack25519(o, n) {
  var i, j, b;
  var m = gf(), t = gf();
  for (i = 0; i < 16; i++) t[i] = n[i];
  car25519(t);
  car25519(t);
  car25519(t);
  for (j = 0; j < 2; j++) {
    m[0] = t[0] - 0xffed;
    for (i = 1; i < 15; i++) {
      m[i] = t[i] - 0xffff - ((m[i-1]>>16) & 1);
      m[i-1] &= 0xffff;
    }
    m[15] = t[15] - 0x7fff - ((m[14]>>16) & 1);
    b = (m[15]>>16) & 1;
    m[14] &= 0xffff;
    sel25519(t, m, 1-b);
  }
  for (i = 0; i < 16; i++) {
    o[2*i] = t[i] & 0xff;
    o[2*i+1] = t[i]>>8;
  }
}

function neq25519(a, b) {
  var c = new Uint8Array(32), d = new Uint8Array(32);
  pack25519(c, a);
  pack25519(d, b);
  return crypto_verify_32(c, 0, d, 0);
}

function par25519(a) {
  var d = new Uint8Array(32);
  pack25519(d, a);
  return d[0] & 1;
}

function unpack25519(o, n) {
  var i;
  for (i = 0; i < 16; i++) o[i] = n[2*i] + (n[2*i+1] << 8);
  o[15] &= 0x7fff;
}

function A(o, a, b) {
  for (var i = 0; i < 16; i++) o[i] = a[i] + b[i];
}

function Z(o, a, b) {
  for (var i = 0; i < 16; i++) o[i] = a[i] - b[i];
}

function M(o, a, b) {
  var v, c,
     t0 = 0,  t1 = 0,  t2 = 0,  t3 = 0,  t4 = 0,  t5 = 0,  t6 = 0,  t7 = 0,
     t8 = 0,  t9 = 0, t10 = 0, t11 = 0, t12 = 0, t13 = 0, t14 = 0, t15 = 0,
    t16 = 0, t17 = 0, t18 = 0, t19 = 0, t20 = 0, t21 = 0, t22 = 0, t23 = 0,
    t24 = 0, t25 = 0, t26 = 0, t27 = 0, t28 = 0, t29 = 0, t30 = 0,
    b0 = b[0],
    b1 = b[1],
    b2 = b[2],
    b3 = b[3],
    b4 = b[4],
    b5 = b[5],
    b6 = b[6],
    b7 = b[7],
    b8 = b[8],
    b9 = b[9],
    b10 = b[10],
    b11 = b[11],
    b12 = b[12],
    b13 = b[13],
    b14 = b[14],
    b15 = b[15];

  v = a[0];
  t0 += v * b0;
  t1 += v * b1;
  t2 += v * b2;
  t3 += v * b3;
  t4 += v * b4;
  t5 += v * b5;
  t6 += v * b6;
  t7 += v * b7;
  t8 += v * b8;
  t9 += v * b9;
  t10 += v * b10;
  t11 += v * b11;
  t12 += v * b12;
  t13 += v * b13;
  t14 += v * b14;
  t15 += v * b15;
  v = a[1];
  t1 += v * b0;
  t2 += v * b1;
  t3 += v * b2;
  t4 += v * b3;
  t5 += v * b4;
  t6 += v * b5;
  t7 += v * b6;
  t8 += v * b7;
  t9 += v * b8;
  t10 += v * b9;
  t11 += v * b10;
  t12 += v * b11;
  t13 += v * b12;
  t14 += v * b13;
  t15 += v * b14;
  t16 += v * b15;
  v = a[2];
  t2 += v * b0;
  t3 += v * b1;
  t4 += v * b2;
  t5 += v * b3;
  t6 += v * b4;
  t7 += v * b5;
  t8 += v * b6;
  t9 += v * b7;
  t10 += v * b8;
  t11 += v * b9;
  t12 += v * b10;
  t13 += v * b11;
  t14 += v * b12;
  t15 += v * b13;
  t16 += v * b14;
  t17 += v * b15;
  v = a[3];
  t3 += v * b0;
  t4 += v * b1;
  t5 += v * b2;
  t6 += v * b3;
  t7 += v * b4;
  t8 += v * b5;
  t9 += v * b6;
  t10 += v * b7;
  t11 += v * b8;
  t12 += v * b9;
  t13 += v * b10;
  t14 += v * b11;
  t15 += v * b12;
  t16 += v * b13;
  t17 += v * b14;
  t18 += v * b15;
  v = a[4];
  t4 += v * b0;
  t5 += v * b1;
  t6 += v * b2;
  t7 += v * b3;
  t8 += v * b4;
  t9 += v * b5;
  t10 += v * b6;
  t11 += v * b7;
  t12 += v * b8;
  t13 += v * b9;
  t14 += v * b10;
  t15 += v * b11;
  t16 += v * b12;
  t17 += v * b13;
  t18 += v * b14;
  t19 += v * b15;
  v = a[5];
  t5 += v * b0;
  t6 += v * b1;
  t7 += v * b2;
  t8 += v * b3;
  t9 += v * b4;
  t10 += v * b5;
  t11 += v * b6;
  t12 += v * b7;
  t13 += v * b8;
  t14 += v * b9;
  t15 += v * b10;
  t16 += v * b11;
  t17 += v * b12;
  t18 += v * b13;
  t19 += v * b14;
  t20 += v * b15;
  v = a[6];
  t6 += v * b0;
  t7 += v * b1;
  t8 += v * b2;
  t9 += v * b3;
  t10 += v * b4;
  t11 += v * b5;
  t12 += v * b6;
  t13 += v * b7;
  t14 += v * b8;
  t15 += v * b9;
  t16 += v * b10;
  t17 += v * b11;
  t18 += v * b12;
  t19 += v * b13;
  t20 += v * b14;
  t21 += v * b15;
  v = a[7];
  t7 += v * b0;
  t8 += v * b1;
  t9 += v * b2;
  t10 += v * b3;
  t11 += v * b4;
  t12 += v * b5;
  t13 += v * b6;
  t14 += v * b7;
  t15 += v * b8;
  t16 += v * b9;
  t17 += v * b10;
  t18 += v * b11;
  t19 += v * b12;
  t20 += v * b13;
  t21 += v * b14;
  t22 += v * b15;
  v = a[8];
  t8 += v * b0;
  t9 += v * b1;
  t10 += v * b2;
  t11 += v * b3;
  t12 += v * b4;
  t13 += v * b5;
  t14 += v * b6;
  t15 += v * b7;
  t16 += v * b8;
  t17 += v * b9;
  t18 += v * b10;
  t19 += v * b11;
  t20 += v * b12;
  t21 += v * b13;
  t22 += v * b14;
  t23 += v * b15;
  v = a[9];
  t9 += v * b0;
  t10 += v * b1;
  t11 += v * b2;
  t12 += v * b3;
  t13 += v * b4;
  t14 += v * b5;
  t15 += v * b6;
  t16 += v * b7;
  t17 += v * b8;
  t18 += v * b9;
  t19 += v * b10;
  t20 += v * b11;
  t21 += v * b12;
  t22 += v * b13;
  t23 += v * b14;
  t24 += v * b15;
  v = a[10];
  t10 += v * b0;
  t11 += v * b1;
  t12 += v * b2;
  t13 += v * b3;
  t14 += v * b4;
  t15 += v * b5;
  t16 += v * b6;
  t17 += v * b7;
  t18 += v * b8;
  t19 += v * b9;
  t20 += v * b10;
  t21 += v * b11;
  t22 += v * b12;
  t23 += v * b13;
  t24 += v * b14;
  t25 += v * b15;
  v = a[11];
  t11 += v * b0;
  t12 += v * b1;
  t13 += v * b2;
  t14 += v * b3;
  t15 += v * b4;
  t16 += v * b5;
  t17 += v * b6;
  t18 += v * b7;
  t19 += v * b8;
  t20 += v * b9;
  t21 += v * b10;
  t22 += v * b11;
  t23 += v * b12;
  t24 += v * b13;
  t25 += v * b14;
  t26 += v * b15;
  v = a[12];
  t12 += v * b0;
  t13 += v * b1;
  t14 += v * b2;
  t15 += v * b3;
  t16 += v * b4;
  t17 += v * b5;
  t18 += v * b6;
  t19 += v * b7;
  t20 += v * b8;
  t21 += v * b9;
  t22 += v * b10;
  t23 += v * b11;
  t24 += v * b12;
  t25 += v * b13;
  t26 += v * b14;
  t27 += v * b15;
  v = a[13];
  t13 += v * b0;
  t14 += v * b1;
  t15 += v * b2;
  t16 += v * b3;
  t17 += v * b4;
  t18 += v * b5;
  t19 += v * b6;
  t20 += v * b7;
  t21 += v * b8;
  t22 += v * b9;
  t23 += v * b10;
  t24 += v * b11;
  t25 += v * b12;
  t26 += v * b13;
  t27 += v * b14;
  t28 += v * b15;
  v = a[14];
  t14 += v * b0;
  t15 += v * b1;
  t16 += v * b2;
  t17 += v * b3;
  t18 += v * b4;
  t19 += v * b5;
  t20 += v * b6;
  t21 += v * b7;
  t22 += v * b8;
  t23 += v * b9;
  t24 += v * b10;
  t25 += v * b11;
  t26 += v * b12;
  t27 += v * b13;
  t28 += v * b14;
  t29 += v * b15;
  v = a[15];
  t15 += v * b0;
  t16 += v * b1;
  t17 += v * b2;
  t18 += v * b3;
  t19 += v * b4;
  t20 += v * b5;
  t21 += v * b6;
  t22 += v * b7;
  t23 += v * b8;
  t24 += v * b9;
  t25 += v * b10;
  t26 += v * b11;
  t27 += v * b12;
  t28 += v * b13;
  t29 += v * b14;
  t30 += v * b15;

  t0  += 38 * t16;
  t1  += 38 * t17;
  t2  += 38 * t18;
  t3  += 38 * t19;
  t4  += 38 * t20;
  t5  += 38 * t21;
  t6  += 38 * t22;
  t7  += 38 * t23;
  t8  += 38 * t24;
  t9  += 38 * t25;
  t10 += 38 * t26;
  t11 += 38 * t27;
  t12 += 38 * t28;
  t13 += 38 * t29;
  t14 += 38 * t30;
  // t15 left as is

  // first car
  c = 1;
  v =  t0 + c + 65535; c = Math.floor(v / 65536);  t0 = v - c * 65536;
  v =  t1 + c + 65535; c = Math.floor(v / 65536);  t1 = v - c * 65536;
  v =  t2 + c + 65535; c = Math.floor(v / 65536);  t2 = v - c * 65536;
  v =  t3 + c + 65535; c = Math.floor(v / 65536);  t3 = v - c * 65536;
  v =  t4 + c + 65535; c = Math.floor(v / 65536);  t4 = v - c * 65536;
  v =  t5 + c + 65535; c = Math.floor(v / 65536);  t5 = v - c * 65536;
  v =  t6 + c + 65535; c = Math.floor(v / 65536);  t6 = v - c * 65536;
  v =  t7 + c + 65535; c = Math.floor(v / 65536);  t7 = v - c * 65536;
  v =  t8 + c + 65535; c = Math.floor(v / 65536);  t8 = v - c * 65536;
  v =  t9 + c + 65535; c = Math.floor(v / 65536);  t9 = v - c * 65536;
  v = t10 + c + 65535; c = Math.floor(v / 65536); t10 = v - c * 65536;
  v = t11 + c + 65535; c = Math.floor(v / 65536); t11 = v - c * 65536;
  v = t12 + c + 65535; c = Math.floor(v / 65536); t12 = v - c * 65536;
  v = t13 + c + 65535; c = Math.floor(v / 65536); t13 = v - c * 65536;
  v = t14 + c + 65535; c = Math.floor(v / 65536); t14 = v - c * 65536;
  v = t15 + c + 65535; c = Math.floor(v / 65536); t15 = v - c * 65536;
  t0 += c-1 + 37 * (c-1);

  // second car
  c = 1;
  v =  t0 + c + 65535; c = Math.floor(v / 65536);  t0 = v - c * 65536;
  v =  t1 + c + 65535; c = Math.floor(v / 65536);  t1 = v - c * 65536;
  v =  t2 + c + 65535; c = Math.floor(v / 65536);  t2 = v - c * 65536;
  v =  t3 + c + 65535; c = Math.floor(v / 65536);  t3 = v - c * 65536;
  v =  t4 + c + 65535; c = Math.floor(v / 65536);  t4 = v - c * 65536;
  v =  t5 + c + 65535; c = Math.floor(v / 65536);  t5 = v - c * 65536;
  v =  t6 + c + 65535; c = Math.floor(v / 65536);  t6 = v - c * 65536;
  v =  t7 + c + 65535; c = Math.floor(v / 65536);  t7 = v - c * 65536;
  v =  t8 + c + 65535; c = Math.floor(v / 65536);  t8 = v - c * 65536;
  v =  t9 + c + 65535; c = Math.floor(v / 65536);  t9 = v - c * 65536;
  v = t10 + c + 65535; c = Math.floor(v / 65536); t10 = v - c * 65536;
  v = t11 + c + 65535; c = Math.floor(v / 65536); t11 = v - c * 65536;
  v = t12 + c + 65535; c = Math.floor(v / 65536); t12 = v - c * 65536;
  v = t13 + c + 65535; c = Math.floor(v / 65536); t13 = v - c * 65536;
  v = t14 + c + 65535; c = Math.floor(v / 65536); t14 = v - c * 65536;
  v = t15 + c + 65535; c = Math.floor(v / 65536); t15 = v - c * 65536;
  t0 += c-1 + 37 * (c-1);

  o[ 0] = t0;
  o[ 1] = t1;
  o[ 2] = t2;
  o[ 3] = t3;
  o[ 4] = t4;
  o[ 5] = t5;
  o[ 6] = t6;
  o[ 7] = t7;
  o[ 8] = t8;
  o[ 9] = t9;
  o[10] = t10;
  o[11] = t11;
  o[12] = t12;
  o[13] = t13;
  o[14] = t14;
  o[15] = t15;
}

function S(o, a) {
  M(o, a, a);
}

function inv25519(o, i) {
  var c = gf();
  var a;
  for (a = 0; a < 16; a++) c[a] = i[a];
  for (a = 253; a >= 0; a--) {
    S(c, c);
    if(a !== 2 && a !== 4) M(c, c, i);
  }
  for (a = 0; a < 16; a++) o[a] = c[a];
}

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];
}

function crypto_scalarmult(q, n, p) {
  var z = new Uint8Array(32);
  var x = new Float64Array(80), r, i;
  var a = gf(), b = gf(), c = gf(),
      d = gf(), e = gf(), f = gf();
  for (i = 0; i < 31; i++) z[i] = n[i];
  z[31]=(n[31]&127)|64;
  z[0]&=248;
  unpack25519(x,p);
  for (i = 0; i < 16; i++) {
    b[i]=x[i];
    d[i]=a[i]=c[i]=0;
  }
  a[0]=d[0]=1;
  for (i=254; i>=0; --i) {
    r=(z[i>>>3]>>>(i&7))&1;
    sel25519(a,b,r);
    sel25519(c,d,r);
    A(e,a,c);
    Z(a,a,c);
    A(c,b,d);
    Z(b,b,d);
    S(d,e);
    S(f,a);
    M(a,c,a);
    M(c,b,e);
    A(e,a,c);
    Z(a,a,c);
    S(b,a);
    Z(c,d,f);
    M(a,c,_121665);
    A(a,a,d);
    M(c,c,a);
    M(a,d,f);
    M(d,b,x);
    S(b,e);
    sel25519(a,b,r);
    sel25519(c,d,r);
  }
  for (i = 0; i < 16; i++) {
    x[i+16]=a[i];
    x[i+32]=c[i];
    x[i+48]=b[i];
    x[i+64]=d[i];
  }
  var x32 = x.subarray(32);
  var x16 = x.subarray(16);
  inv25519(x32,x32);
  M(x16,x16,x32);
  pack25519(q,x16);
  return 0;
}

function crypto_scalarmult_base(q, n) {
  return crypto_scalarmult(q, n, _9);
}

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_hash(pk, sk, hashfunc) {
  var d = new Uint8Array(64);
  var p = [gf(), gf(), gf(), gf()];
  var i;

  hashfunc(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_shared_key_hash(shared, pk, sk, hashfunc) {
  var d = new Uint8Array(64);
  var p = [gf(), gf(), gf(), gf()];

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

  var q = [gf(), gf(), gf(), gf()];
  unpack(q, pk);
  scalarmult(p, q, d);
  pack(shared, p);
}

function crypto_sign_hash(sm, keypair, data, hasher) {
  var privHash = new Uint8Array(64);
  var seededHash = new Uint8Array(64);
  var result = new Uint8Array(64);
  var p = [gf(), gf(), gf(), gf()];
  var i;

  hasher.update(keypair.secretKey);
  hasher.finalize(privHash);

  privHash[0] &= 248;
  privHash[31] &= 127;
  privHash[31] |= 64;

  hasher.reset();
  hasher.update(privHash.slice(32));
  hasher.update(data);
  hasher.finalize(seededHash);

  reduce(seededHash);
  scalarbase(p, seededHash);
  pack(sm, p);
  
  hasher.reset();
  hasher.update(sm.slice(0, 32));
  hasher.update(keypair.publicKey)
  hasher.update(data);
  hasher.finalize(result);

  reduce(result);
  

  // muladd - this is from original tweetnacl-js
  var x = new Float64Array(64);
  for (var i = 0; i < 64; i++) x[i] = 0;
  for (var i = 0; i < 32; i++) x[i] = seededHash[i];
  for (var i = 0; i < 32; i++) {
    for (var j = 0; j < 32; j++) {
      x[i+j] += result[i] * privHash[j];
    }
  }
  modL(sm.subarray(32), x);

  // check if zero
  var isZero = 0;
  for (var i = 0; i < 32; i++)
  {
	  isZero |= sm[32+i] ^ 0;
	  result[i] = sm[32+i];
  }

  if (isZero == 0)
	  return false;

  reduce(result);

  // check if canonical
  isZero = 0;
  for (var i = 0; i < 32; i++)
  {
	  isZero |= sm[32+i] ^ result[i];
  }
  return isZero == 0;
}

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);
}

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);

  // num = u = y^2 - 1
  // den = v = d * y^2 + 1
  S(num, r[1]);
  M(den, num, D);
  Z(num, num, r[2]);
  A(den, r[2], den);

  // r[0] = x = sqrt(u / v)
  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 unpack(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);

  // num = u = y^2 - 1
  // den = v = d * y^2 + 1
  S(num, r[1]);
  M(den, num, D);
  Z(num, num, r[2]);
  A(den, r[2], den);

  // r[0] = x = sqrt(u / v)
  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)) {
    console.log("not a valid Ed25519EncodedGroupElement.");
    return -1;
  }

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

  M(r[3], r[0], r[1]);
  return 0;
}
var 
    crypto_scalarmult_BYTES = 32,
    crypto_scalarmult_SCALARBYTES = 32,
    crypto_sign_BYTES = 64,
    crypto_sign_PUBLICKEYBYTES = 32,
    crypto_sign_SECRETKEYBYTES = 64,
    crypto_sign_SEEDBYTES = 32,
    crypto_hash_BYTES = 64;

nacl.lowlevel = {
  crypto_verify_32: crypto_verify_32,
  crypto_scalarmult: crypto_scalarmult,
  crypto_scalarmult_base: crypto_scalarmult_base,
  crypto_sign_keypair_hash: crypto_sign_keypair_hash,
  crypto_shared_key_hash: crypto_shared_key_hash,
  crypto_sign_hash: crypto_sign_hash,

  crypto_scalarmult_BYTES: crypto_scalarmult_BYTES,
  crypto_scalarmult_SCALARBYTES: crypto_scalarmult_SCALARBYTES,
  crypto_sign_BYTES: crypto_sign_BYTES,
  crypto_sign_PUBLICKEYBYTES: crypto_sign_PUBLICKEYBYTES,
  crypto_sign_SECRETKEYBYTES: crypto_sign_SECRETKEYBYTES,
  crypto_sign_SEEDBYTES: crypto_sign_SEEDBYTES,
  crypto_hash_BYTES: crypto_hash_BYTES
};

/* High-level API */

function checkArrayTypes() {
  var t, i;
  for (i = 0; i < arguments.length; i++) {
     if ((t = Object.prototype.toString.call(arguments[i])) !== '[object Uint8Array]')
       throw new TypeError('unexpected type ' + t + ', use Uint8Array');
  }
}

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

nacl.randomBytes = function(n) {
  var b = new Uint8Array(n);
  randombytes(b, n);
  return b;
};

nacl.scalarMult = function(n, p) {
  checkArrayTypes(n, p);
  if (n.length !== crypto_scalarmult_SCALARBYTES) throw new Error('bad n size');
  if (p.length !== crypto_scalarmult_BYTES) throw new Error('bad p size');
  var q = new Uint8Array(crypto_scalarmult_BYTES);
  crypto_scalarmult(q, n, p);
  return q;
};

nacl.scalarMult.base = function(n) {
  checkArrayTypes(n);
  if (n.length !== crypto_scalarmult_SCALARBYTES) throw new Error('bad n size');
  var q = new Uint8Array(crypto_scalarmult_BYTES);
  crypto_scalarmult_base(q, n);
  return q;
};

nacl.scalarMult.scalarLength = crypto_scalarmult_SCALARBYTES;
nacl.scalarMult.groupElementLength = crypto_scalarmult_BYTES;

nacl.verify = function(x, y) {
  checkArrayTypes(x, y);
  // Zero length arguments are considered not equal.
  if (x.length === 0 || y.length === 0) return false;
  if (x.length !== y.length) return false;
  return (vn(x, 0, y, 0, x.length) === 0) ? true : false;
};

nacl.setPRNG = function(fn) {
  randombytes = fn;
};

(function() {
  // Initialize PRNG if environment provides CSPRNG.
  // If not, methods calling randombytes will throw.
  var crypto;
  if (typeof window !== 'undefined') {
    // Browser.
    if (window.crypto && window.crypto.getRandomValues) {
      crypto = window.crypto; // Standard
    } else if (window.msCrypto && window.msCrypto.getRandomValues) {
      crypto = window.msCrypto; // Internet Explorer 11+
    }
    if (crypto) {
      nacl.setPRNG(function(x, n) {
        var i, v = new Uint8Array(n);
        crypto.getRandomValues(v);
        for (i = 0; i < n; i++) x[i] = v[i];
        cleanup(v);
      });
    }
  } else if (typeof require !== 'undefined') {
    // Node.js.
    crypto = require('crypto');
    if (crypto) {
      nacl.setPRNG(function(x, n) {
        var i, v = crypto.randomBytes(n);
        for (i = 0; i < n; i++) x[i] = v[i];
        cleanup(v);
      });
    }
  }
})();

})(typeof module !== 'undefined' && module.exports ? module.exports : (window.nacl = window.nacl || {}));