/*(c) 2006 - 2008 AllenPort Co. All Rights Reserved.
All versions of this code, including the source and executable versions, 
constitute the intellectual property of AllenPort Co., which expressly reserves 
any and all U.S. and foreign rights and benefits to the code under copyright, 
trade secret and any other intellectual property law or international treaty 
whatsoever. Use of the code is subject to the terms and conditions of a separate 
written license agreement, and the code shall not be reproduced, modified, distributed 
or otherwise used in any form or manner whatsoever without obtaining the prior written 
permission of AllenPort Co. Any unauthorized reproduction or distribution of the code, 
or any portion of it, may result in civil and criminal penalties and be prosecuted 
to the fullest extent of the law.*/
// Depends on jsbn.js and rng.js

// convert a (hex) string to a bignum object
function parseBigInt(str,r) {
  return new BigInteger(str,r);
}

function linebrk(s,n) {
  var ret = "";
  var i = 0;
  while(i + n < s.length) {
    ret += s.substring(i,i+n) + "\n";
    i += n;
  }
  return ret + s.substring(i,s.length);
}

function byte2Hex(b) {
  if(b < 0x10)
    return "0" + b.toString(16);
  else
    return b.toString(16);
}

// PKCS#1 (type 2, random) pad input string s to n bytes, and return a bigint
function pkcs1pad2(s,n) {
  if(n < s.length + 11) {
    //alert("Message too long for RSA " + n + " Str=" + s + " " + s.length);
    return null;
  }
  var ba = new Array();
  var i = s.length - 1;
  while(i >= 0 && n > 0) ba[--n] = s.charCodeAt(i--);
  ba[--n] = 0;
  var rng = new SecureRandom();
  var x = new Array();
  while(n > 2) { // random non-zero pad
    x[0] = 0;
    while(x[0] == 0) rng.nextBytes(x);
    ba[--n] = x[0];
  }
  ba[--n] = 2;
  ba[--n] = 0;
  return new BigInteger(ba);
}

// "empty" RSA key constructor
function RSAKey() {
  this.n = null;
  this.e = 0;
  this.d = null;
  this.p = null;
  this.q = null;
  this.dmp1 = null;
  this.dmq1 = null;
  this.coeff = null;
  //Needed to RSAGenerateEx
  this.local_context = {state:null, rng:null, qs:null, ee:null, e:null, p:null, q:null, isGenerated:null};
  this.B_arg = null;
  this.E_arg = null;
}

// Set the public key fields N and e from hex strings
function RSASetPublic(N,E) {
  if(N != null && E != null && N.length > 0 && E.length > 0) {
    this.n = parseBigInt(N,16);
    this.e = parseInt(E,16);
  }
  else
  {
    //alert("Invalid RSA public key");
  }
}

// Perform raw public operation on "x": return x^e (mod n)
function RSADoPublic(x) {
  return x.modPowInt(this.e, this.n);
}

// Return the PKCS#1 RSA encryption of "text" as an even-length hex string
function RSAEncrypt(text) {
  var m = pkcs1pad2(text,(this.n.bitLength()+7)>>3);
  if(m == null) return null;
  var c = this.doPublic(m);
  if(c == null) return null;
  var h = c.toString(16);
  if((h.length & 1) == 0) return h; else return "0" + h;
}

// Return the PKCS#1 RSA encryption of "text" as a Base64-encoded string
//function RSAEncryptB64(text) {
//  var h = this.encrypt(text);
//  if(h) return hex2b64(h); else return null;
//}

// protected
RSAKey.prototype.doPublic = RSADoPublic;

// public
RSAKey.prototype.setPublic = RSASetPublic;
RSAKey.prototype.encrypt = RSAEncrypt;
//RSAKey.prototype.encrypt_b64 = RSAEncryptB64;