// Copyright (c) 2005-2009  Tom Wu
// All Rights Reserved.
// See "LICENSE" for details.

// Extended JavaScript BN functions, required for RSA private ops.

// Version 1.1: new BigInteger("0", 10) returns "proper" zero
// Version 1.2: square() API, isProbablePrime fix

// (public)
function bnClone() { var r = nbi(); this.copyTo(r); return r; }

// (public) return value as integer
function bnIntValue() {
  if(this.s < 0) {
    if(this.t == 1) return this[0]-this.DV;
    else if(this.t == 0) return -1;
  }
  else if(this.t == 1) return this[0];
  else if(this.t == 0) return 0;
  // assumes 16 < DB < 32
  return ((this[1]&((1<<(32-this.DB))-1))<<this.DB)|this[0];
}

// (public) return value as byte
function bnByteValue() { return (this.t==0)?this.s:(this[0]<<24)>>24; }

// (public) return value as short (assumes DB>=16)
function bnShortValue() { return (this.t==0)?this.s:(this[0]<<16)>>16; }

// (protected) return x s.t. r^x < DV
function bnpChunkSize(r) { return Math.floor(Math.LN2*this.DB/Math.log(r)); }

// (public) 0 if this == 0, 1 if this > 0
function bnSigNum() {
  if(this.s < 0) return -1;
  else if(this.t <= 0 || (this.t == 1 && this[0] <= 0)) return 0;
  else return 1;
}

// (protected) convert to radix string
function bnpToRadix(b) {
  if(b == null) b = 10;
  if(this.signum() == 0 || b < 2 || b > 36) return "0";
  var cs = this.chunkSize(b);
  var a = Math.pow(b,cs);
  var d = nbv(a), y = nbi(), z = nbi(), r = "";
  this.divRemTo(d,y,z);
  while(y.signum() > 0) {
    r = (a+z.intValue()).toString(b).substr(1) + r;
    y.divRemTo(d,y,z);
  }
  return z.intValue().toString(b) + r;
}

// (protected) convert from radix string
function bnpFromRadix(s,b) {
  this.fromInt(0);
  if(b == null) b = 10;
  var cs = this.chunkSize(b);
  var d = Math.pow(b,cs), mi = false, j = 0, w = 0;
  for(var i = 0; i < s.length; ++i) {
    var x = intAt(s,i);
    if(x < 0) {
      if(s.charAt(i) == "-" && this.signum() == 0) mi = true;
      continue;
    }
    w = b*w+x;
    if(++j >= cs) {
      this.dMultiply(d);
      this.dAddOffset(w,0);
      j = 0;
      w = 0;
    }
  }
  if(j > 0) {
    this.dMultiply(Math.pow(b,j));
    this.dAddOffset(w,0);
  }
  if(mi) BigInteger.ZERO.subTo(this,this);
}

// (protected) alternate constructor
function bnpFromNumber(a,b,c) {
  if("number" == typeof b) {
    // new BigInteger(int,int,RNG)
    if(a < 2) this.fromInt(1);
    else {
      this.fromNumber(a,c);
      if(!this.testBit(a-1))	// force MSB set
        this.bitwiseTo(BigInteger.ONE.shiftLeft(a-1),op_or,this);
      if(this.isEven()) this.dAddOffset(1,0); // force odd
      while(!this.isProbablePrime(b)) {
        this.dAddOffset(2,0);
        if(this.bitLength() > a) this.subTo(BigInteger.ONE.shiftLeft(a-1),this);
      }
    }
  }
  else {
    // new BigInteger(int,RNG)
    var x = new Array(), t = a&7;
    x.length = (a>>3)+1;
    b.nextBytes(x);
    if(t > 0) x[0] &= ((1<<t)-1); else x[0] = 0;
    this.fromString(x,256);
  }
}

// (public) convert to bigendian byte array
function bnToByteArray() {
  var i = this.t, r = new Array();
  r[0] = this.s;
  var p = this.DB-(i*this.DB)%8, d, k = 0;
  if(i-- > 0) {
    if(p < this.DB && (d = this[i]>>p) != (this.s&this.DM)>>p)
      r[k++] = d|(this.s<<(this.DB-p));
    while(i >= 0) {
      if(p < 8) {
        d = (this[i]&((1<<p)-1))<<(8-p);
        d |= this[--i]>>(p+=this.DB-8);
      }
      else {
        d = (this[i]>>(p-=8))&0xff;
        if(p <= 0) { p += this.DB; --i; }
      }
      if((d&0x80) != 0) d |= -256;
      if(k == 0 && (this.s&0x80) != (d&0x80)) ++k;
      if(k > 0 || d != this.s) r[k++] = d;
    }
  }
  return r;
}

function bnEquals(a) { return(this.compareTo(a)==0); }
function bnMin(a) { return(this.compareTo(a)<0)?this:a; }
function bnMax(a) { return(this.compareTo(a)>0)?this:a; }

// (protected) r = this op a (bitwise)
function bnpBitwiseTo(a,op,r) {
  var i, f, m = Math.min(a.t,this.t);
  for(i = 0; i < m; ++i) r[i] = op(this[i],a[i]);
  if(a.t < this.t) {
    f = a.s&this.DM;
    for(i = m; i < this.t; ++i) r[i] = op(this[i],f);
    r.t = this.t;
  }
  else {
    f = this.s&this.DM;
    for(i = m; i < a.t; ++i) r[i] = op(f,a[i]);
    r.t = a.t;
  }
  r.s = op(this.s,a.s);
  r.clamp();
}

// (public) this & a
function op_and(x,y) { return x&y; }
function bnAnd(a) { var r = nbi(); this.bitwiseTo(a,op_and,r); return r; }

// (public) this | a
function op_or(x,y) { return x|y; }
function bnOr(a) { var r = nbi(); this.bitwiseTo(a,op_or,r); return r; }

// (public) this ^ a
function op_xor(x,y) { return x^y; }
function bnXor(a) { var r = nbi(); this.bitwiseTo(a,op_xor,r); return r; }

// (public) this & ~a
function op_andnot(x,y) { return x&~y; }
function bnAndNot(a) { var r = nbi(); this.bitwiseTo(a,op_andnot,r); return r; }

// (public) ~this
function bnNot() {
  var r = nbi();
  for(var i = 0; i < this.t; ++i) r[i] = this.DM&~this[i];
  r.t = this.t;
  r.s = ~this.s;
  return r;
}

// (public) this << n
function bnShiftLeft(n) {
  var r = nbi();
  if(n < 0) this.rShiftTo(-n,r); else this.lShiftTo(n,r);
  return r;
}

// (public) this >> n
function bnShiftRight(n) {
  var r = nbi();
  if(n < 0) this.lShiftTo(-n,r); else this.rShiftTo(n,r);
  return r;
}

// return index of lowest 1-bit in x, x < 2^31
function lbit(x) {
  if(x == 0) return -1;
  var r = 0;
  if((x&0xffff) == 0) { x >>= 16; r += 16; }
  if((x&0xff) == 0) { x >>= 8; r += 8; }
  if((x&0xf) == 0) { x >>= 4; r += 4; }
  if((x&3) == 0) { x >>= 2; r += 2; }
  if((x&1) == 0) ++r;
  return r;
}

// (public) returns index of lowest 1-bit (or -1 if none)
function bnGetLowestSetBit() {
  for(var i = 0; i < this.t; ++i)
    if(this[i] != 0) return i*this.DB+lbit(this[i]);
  if(this.s < 0) return this.t*this.DB;
  return -1;
}

// return number of 1 bits in x
function cbit(x) {
  var r = 0;
  while(x != 0) { x &= x-1; ++r; }
  return r;
}

// (public) return number of set bits
function bnBitCount() {
  var r = 0, x = this.s&this.DM;
  for(var i = 0; i < this.t; ++i) r += cbit(this[i]^x);
  return r;
}

// (public) true iff nth bit is set
function bnTestBit(n) {
  var j = Math.floor(n/this.DB);
  if(j >= this.t) return(this.s!=0);
  return((this[j]&(1<<(n%this.DB)))!=0);
}

// (protected) this op (1<<n)
function bnpChangeBit(n,op) {
  var r = BigInteger.ONE.shiftLeft(n);
  this.bitwiseTo(r,op,r);
  return r;
}

// (public) this | (1<<n)
function bnSetBit(n) { return this.changeBit(n,op_or); }

// (public) this & ~(1<<n)
function bnClearBit(n) { return this.changeBit(n,op_andnot); }

// (public) this ^ (1<<n)
function bnFlipBit(n) { return this.changeBit(n,op_xor); }

// (protected) r = this + a
function bnpAddTo(a,r) {
  var i = 0, c = 0, m = Math.min(a.t,this.t);
  while(i < m) {
    c += this[i]+a[i];
    r[i++] = c&this.DM;
    c >>= this.DB;
  }
  if(a.t < this.t) {
    c += a.s;
    while(i < this.t) {
      c += this[i];
      r[i++] = c&this.DM;
      c >>= this.DB;
    }
    c += this.s;
  }
  else {
    c += this.s;
    while(i < a.t) {
      c += a[i];
      r[i++] = c&this.DM;
      c >>= this.DB;
    }
    c += a.s;
  }
  r.s = (c<0)?-1:0;
  if(c > 0) r[i++] = c;
  else if(c < -1) r[i++] = this.DV+c;
  r.t = i;
  r.clamp();
}

// (public) this + a
function bnAdd(a) { var r = nbi(); this.addTo(a,r); return r; }

// (public) this - a
function bnSubtract(a) { var r = nbi(); this.subTo(a,r); return r; }

// (public) this * a
function bnMultiply(a) { var r = nbi(); this.multiplyTo(a,r); return r; }

// (public) this^2
function bnSquare() { var r = nbi(); this.squareTo(r); return r; }

// (public) this / a
function bnDivide(a) { var r = nbi(); this.divRemTo(a,r,null); return r; }

// (public) this % a
function bnRemainder(a) { var r = nbi(); this.divRemTo(a,null,r); return r; }

// (public) [this/a,this%a]
function bnDivideAndRemainder(a) {
  var q = nbi(), r = nbi();
  this.divRemTo(a,q,r);
  return new Array(q,r);
}

// (protected) this *= n, this >= 0, 1 < n < DV
function bnpDMultiply(n) {
  this[this.t] = this.am(0,n-1,this,0,0,this.t);
  ++this.t;
  this.clamp();
}

// (protected) this += n << w words, this >= 0
function bnpDAddOffset(n,w) {
  if(n == 0) return;
  while(this.t <= w) this[this.t++] = 0;
  this[w] += n;
  while(this[w] >= this.DV) {
    this[w] -= this.DV;
    if(++w >= this.t) this[this.t++] = 0;
    ++this[w];
  }
}

// A "null" reducer
function NullExp() {}
function nNop(x) { return x; }
function nMulTo(x,y,r) { x.multiplyTo(y,r); }
function nSqrTo(x,r) { x.squareTo(r); }

NullExp.prototype.convert = nNop;
NullExp.prototype.revert = nNop;
NullExp.prototype.mulTo = nMulTo;
NullExp.prototype.sqrTo = nSqrTo;

// (public) this^e
function bnPow(e) { return this.exp(e,new NullExp()); }

// (protected) r = lower n words of "this * a", a.t <= n
// "this" should be the larger one if appropriate.
function bnpMultiplyLowerTo(a,n,r) {
  var i = Math.min(this.t+a.t,n);
  r.s = 0; // assumes a,this >= 0
  r.t = i;
  while(i > 0) r[--i] = 0;
  var j;
  for(j = r.t-this.t; i < j; ++i) r[i+this.t] = this.am(0,a[i],r,i,0,this.t);
  for(j = Math.min(a.t,n); i < j; ++i) this.am(0,a[i],r,i,0,n-i);
  r.clamp();
}

// (protected) r = "this * a" without lower n words, n > 0
// "this" should be the larger one if appropriate.
function bnpMultiplyUpperTo(a,n,r) {
  --n;
  var i = r.t = this.t+a.t-n;
  r.s = 0; // assumes a,this >= 0
  while(--i >= 0) r[i] = 0;
  for(i = Math.max(n-this.t,0); i < a.t; ++i)
    r[this.t+i-n] = this.am(n-i,a[i],r,0,0,this.t+i-n);
  r.clamp();
  r.drShiftTo(1,r);
}

// Barrett modular reduction
function Barrett(m) {
  // setup Barrett
  this.r2 = nbi();
  this.q3 = nbi();
  BigInteger.ONE.dlShiftTo(2*m.t,this.r2);
  this.mu = this.r2.divide(m);
  this.m = m;
}

function barrettConvert(x) {
  if(x.s < 0 || x.t > 2*this.m.t) return x.mod(this.m);
  else if(x.compareTo(this.m) < 0) return x;
  else { var r = nbi(); x.copyTo(r); this.reduce(r); return r; }
}

function barrettRevert(x) { return x; }

// x = x mod m (HAC 14.42)
function barrettReduce(x) {
  x.drShiftTo(this.m.t-1,this.r2);
  if(x.t > this.m.t+1) { x.t = this.m.t+1; x.clamp(); }
  this.mu.multiplyUpperTo(this.r2,this.m.t+1,this.q3);
  this.m.multiplyLowerTo(this.q3,this.m.t+1,this.r2);
  while(x.compareTo(this.r2) < 0) x.dAddOffset(1,this.m.t+1);
  x.subTo(this.r2,x);
  while(x.compareTo(this.m) >= 0) x.subTo(this.m,x);
}

// r = x^2 mod m; x != r
function barrettSqrTo(x,r) { x.squareTo(r); this.reduce(r); }

// r = x*y mod m; x,y != r
function barrettMulTo(x,y,r) { x.multiplyTo(y,r); this.reduce(r); }

Barrett.prototype.convert = barrettConvert;
Barrett.prototype.revert = barrettRevert;
Barrett.prototype.reduce = barrettReduce;
Barrett.prototype.mulTo = barrettMulTo;
Barrett.prototype.sqrTo = barrettSqrTo;

// (public) this^e % m (HAC 14.85)
function bnModPow(e,m) {
  var i = e.bitLength(), k, r = nbv(1), z;
  if(i <= 0) return r;
  else if(i < 18) k = 1;
  else if(i < 48) k = 3;
  else if(i < 144) k = 4;
  else if(i < 768) k = 5;
  else k = 6;
  if(i < 8)
    z = new Classic(m);
  else if(m.isEven())
    z = new Barrett(m);
  else
    z = new Montgomery(m);

  // precomputation
  var g = new Array(), n = 3, k1 = k-1, km = (1<<k)-1;
  g[1] = z.convert(this);
  if(k > 1) {
    var g2 = nbi();
    z.sqrTo(g[1],g2);
    while(n <= km) {
      g[n] = nbi();
      z.mulTo(g2,g[n-2],g[n]);
      n += 2;
    }
  }

  var j = e.t-1, w, is1 = true, r2 = nbi(), t;
  i = nbits(e[j])-1;
  while(j >= 0) {
    if(i >= k1) w = (e[j]>>(i-k1))&km;
    else {
      w = (e[j]&((1<<(i+1))-1))<<(k1-i);
      if(j > 0) w |= e[j-1]>>(this.DB+i-k1);
    }

    n = k;
    while((w&1) == 0) { w >>= 1; --n; }
    if((i -= n) < 0) { i += this.DB; --j; }
    if(is1) {	// ret == 1, don't bother squaring or multiplying it
      g[w].copyTo(r);
      is1 = false;
    }
    else {
      while(n > 1) { z.sqrTo(r,r2); z.sqrTo(r2,r); n -= 2; }
      if(n > 0) z.sqrTo(r,r2); else { t = r; r = r2; r2 = t; }
      z.mulTo(r2,g[w],r);
    }

    while(j >= 0 && (e[j]&(1<<i)) == 0) {
      z.sqrTo(r,r2); t = r; r = r2; r2 = t;
      if(--i < 0) { i = this.DB-1; --j; }
    }
  }
  return z.revert(r);
}

// (public) gcd(this,a) (HAC 14.54)
function bnGCD(a) {
  var x = (this.s<0)?this.negate():this.clone();
  var y = (a.s<0)?a.negate():a.clone();
  if(x.compareTo(y) < 0) { var t = x; x = y; y = t; }
  var i = x.getLowestSetBit(), g = y.getLowestSetBit();
  if(g < 0) return x;
  if(i < g) g = i;
  if(g > 0) {
    x.rShiftTo(g,x);
    y.rShiftTo(g,y);
  }
  while(x.signum() > 0) {
    if((i = x.getLowestSetBit()) > 0) x.rShiftTo(i,x);
    if((i = y.getLowestSetBit()) > 0) y.rShiftTo(i,y);
    if(x.compareTo(y) >= 0) {
      x.subTo(y,x);
      x.rShiftTo(1,x);
    }
    else {
      y.subTo(x,y);
      y.rShiftTo(1,y);
    }
  }
  if(g > 0) y.lShiftTo(g,y);
  return y;
}

// (protected) this % n, n < 2^26
function bnpModInt(n) {
  if(n <= 0) return 0;
  var d = this.DV%n, r = (this.s<0)?n-1:0;
  if(this.t > 0)
    if(d == 0) r = this[0]%n;
    else for(var i = this.t-1; i >= 0; --i) r = (d*r+this[i])%n;
  return r;
}

// (public) 1/this % m (HAC 14.61)
function bnModInverse(m) {
  var ac = m.isEven();
  if((this.isEven() && ac) || m.signum() == 0) return BigInteger.ZERO;
  var u = m.clone(), v = this.clone();
  var a = nbv(1), b = nbv(0), c = nbv(0), d = nbv(1);
  while(u.signum() != 0) {
    while(u.isEven()) {
      u.rShiftTo(1,u);
      if(ac) {
        if(!a.isEven() || !b.isEven()) { a.addTo(this,a); b.subTo(m,b); }
        a.rShiftTo(1,a);
      }
      else if(!b.isEven()) b.subTo(m,b);
      b.rShiftTo(1,b);
    }
    while(v.isEven()) {
      v.rShiftTo(1,v);
      if(ac) {
        if(!c.isEven() || !d.isEven()) { c.addTo(this,c); d.subTo(m,d); }
        c.rShiftTo(1,c);
      }
      else if(!d.isEven()) d.subTo(m,d);
      d.rShiftTo(1,d);
    }
    if(u.compareTo(v) >= 0) {
      u.subTo(v,u);
      if(ac) a.subTo(c,a);
      b.subTo(d,b);
    }
    else {
      v.subTo(u,v);
      if(ac) c.subTo(a,c);
      d.subTo(b,d);
    }
  }
  if(v.compareTo(BigInteger.ONE) != 0) return BigInteger.ZERO;
  if(d.compareTo(m) >= 0) return d.subtract(m);
  if(d.signum() < 0) d.addTo(m,d); else return d;
  if(d.signum() < 0) return d.add(m); else return d;
}

var lowprimes = [2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307,311,313,317,331,337,347,349,353,359,367,373,379,383,389,397,401,409,419,421,431,433,439,443,449,457,461,463,467,479,487,491,499,503,509,521,523,541,547,557,563,569,571,577,587,593,599,601,607,613,617,619,631,641,643,647,653,659,661,673,677,683,691,701,709,719,727,733,739,743,751,757,761,769,773,787,797,809,811,821,823,827,829,839,853,857,859,863,877,881,883,887,907,911,919,929,937,941,947,953,967,971,977,983,991,997];
var lplim = (1<<26)/lowprimes[lowprimes.length-1];

// (public) test primality with certainty >= 1-.5^t
function bnIsProbablePrime(t) {
  var i, x = this.abs();
  if(x.t == 1 && x[0] <= lowprimes[lowprimes.length-1]) {
    for(i = 0; i < lowprimes.length; ++i)
      if(x[0] == lowprimes[i]) return true;
    return false;
  }
  if(x.isEven()) return false;
  i = 1;
  while(i < lowprimes.length) {
    var m = lowprimes[i], j = i+1;
    while(j < lowprimes.length && m < lplim) m *= lowprimes[j++];
    m = x.modInt(m);
    while(i < j) if(m%lowprimes[i++] == 0) return false;
  }
  return x.millerRabin(t);
}

// (protected) true if probably prime (HAC 4.24, Miller-Rabin)
function bnpMillerRabin(t) {
  var n1 = this.subtract(BigInteger.ONE);
  var k = n1.getLowestSetBit();
  if(k <= 0) return false;
  var r = n1.shiftRight(k);
  t = (t+1)>>1;
  if(t > lowprimes.length) t = lowprimes.length;
  var a = nbi();
  for(var i = 0; i < t; ++i) {
    //Pick bases at random, instead of starting at 2
    a.fromInt(lowprimes[Math.floor(Math.random()*lowprimes.length)]);
    var y = a.modPow(r,this);
    if(y.compareTo(BigInteger.ONE) != 0 && y.compareTo(n1) != 0) {
      var j = 1;
      while(j++ < k && y.compareTo(n1) != 0) {
        y = y.modPowInt(2,this);
        if(y.compareTo(BigInteger.ONE) == 0) return false;
      }
      if(y.compareTo(n1) != 0) return false;
    }
  }
  return true;
}

// protected
BigInteger.prototype.chunkSize = bnpChunkSize;
BigInteger.prototype.toRadix = bnpToRadix;
BigInteger.prototype.fromRadix = bnpFromRadix;
BigInteger.prototype.fromNumber = bnpFromNumber;
BigInteger.prototype.bitwiseTo = bnpBitwiseTo;
BigInteger.prototype.changeBit = bnpChangeBit;
BigInteger.prototype.addTo = bnpAddTo;
BigInteger.prototype.dMultiply = bnpDMultiply;
BigInteger.prototype.dAddOffset = bnpDAddOffset;
BigInteger.prototype.multiplyLowerTo = bnpMultiplyLowerTo;
BigInteger.prototype.multiplyUpperTo = bnpMultiplyUpperTo;
BigInteger.prototype.modInt = bnpModInt;
BigInteger.prototype.millerRabin = bnpMillerRabin;

// public
BigInteger.prototype.clone = bnClone;
BigInteger.prototype.intValue = bnIntValue;
BigInteger.prototype.byteValue = bnByteValue;
BigInteger.prototype.shortValue = bnShortValue;
BigInteger.prototype.signum = bnSigNum;
BigInteger.prototype.toByteArray = bnToByteArray;
BigInteger.prototype.equals = bnEquals;
BigInteger.prototype.min = bnMin;
BigInteger.prototype.max = bnMax;
BigInteger.prototype.and = bnAnd;
BigInteger.prototype.or = bnOr;
BigInteger.prototype.xor = bnXor;
BigInteger.prototype.andNot = bnAndNot;
BigInteger.prototype.not = bnNot;
BigInteger.prototype.shiftLeft = bnShiftLeft;
BigInteger.prototype.shiftRight = bnShiftRight;
BigInteger.prototype.getLowestSetBit = bnGetLowestSetBit;
BigInteger.prototype.bitCount = bnBitCount;
BigInteger.prototype.testBit = bnTestBit;
BigInteger.prototype.setBit = bnSetBit;
BigInteger.prototype.clearBit = bnClearBit;
BigInteger.prototype.flipBit = bnFlipBit;
BigInteger.prototype.add = bnAdd;
BigInteger.prototype.subtract = bnSubtract;
BigInteger.prototype.multiply = bnMultiply;
BigInteger.prototype.divide = bnDivide;
BigInteger.prototype.remainder = bnRemainder;
BigInteger.prototype.divideAndRemainder = bnDivideAndRemainder;
BigInteger.prototype.modPow = bnModPow;
BigInteger.prototype.modInverse = bnModInverse;
BigInteger.prototype.pow = bnPow;
BigInteger.prototype.gcd = bnGCD;
BigInteger.prototype.isProbablePrime = bnIsProbablePrime;

// JSBN-specific extension
BigInteger.prototype.square = bnSquare;

// BigInteger interfaces not implemented in jsbn:

// BigInteger(int signum, byte[] magnitude)
// double doubleValue()
// float floatValue()
// int hashCode()
// long longValue()
// static BigInteger valueOf(long val)
