/*
* RSA, a suite of routines for performing RSA public-key computations in JavaScript.
* Copyright 1998-2005 David Shapiro.
* Dave Shapiro
* dave@ohdave.com
* changed by Fuchun, 2010-05-06
* fcrpg2005@gmail.com
*/
(function($w) {
if(typeof $w.RSAUtils === 'undefined')
var RSAUtils = $w.RSAUtils = {};
var biRadixBase = 2;
var biRadixBits = 16;
var bitsPerDigit = biRadixBits;
var biRadix = 1 << 16; // = 2^16 = 65536
var biHalfRadix = biRadix >>> 1;
var biRadixSquared = biRadix * biRadix;
var maxDigitVal = biRadix - 1;
var maxInteger = 9999999999999998;
//maxDigits:
//Change this to accommodate your largest number size. Use setMaxDigits()
//to change it!
//
//In general, if you're working with numbers of size N bits, you'll need 2*N
//bits of storage. Each digit holds 16 bits. So, a 1024-bit key will need
//
//1024 * 2 / 16 = 128 digits of storage.
//
var maxDigits;
var ZERO_ARRAY;
var bigZero, bigOne;
var BigInt = $w.BigInt = function(flag) {
if (typeof flag == "boolean" && flag == true) {
this.digits = null;
} else {
this.digits = ZERO_ARRAY.slice(0);
}
this.isNeg = false;
};
RSAUtils.setMaxDigits = function(value) {
maxDigits = value;
ZERO_ARRAY = new Array(maxDigits);
for (var iza = 0; iza < ZERO_ARRAY.length; iza++) ZERO_ARRAY[iza] = 0;
bigZero = new BigInt();
bigOne = new BigInt();
bigOne.digits[0] = 1;
};
RSAUtils.setMaxDigits(20);
//The maximum number of digits in base 10 you can convert to an
//integer without JavaScript throwing up on you.
var dpl10 = 15;
RSAUtils.biFromNumber = function(i) {
var result = new BigInt();
result.isNeg = i < 0;
i = Math.abs(i);
var j = 0;
while (i > 0) {
result.digits[j++] = i & maxDigitVal;
i = Math.floor(i / biRadix);
}
return result;
};
//lr10 = 10 ^ dpl10
var lr10 = RSAUtils.biFromNumber(1000000000000000);
RSAUtils.biFromDecimal = function(s) {
var isNeg = s.charAt(0) == '-';
var i = isNeg ? 1 : 0;
var result;
// Skip leading zeros.
while (i < s.length && s.charAt(i) == '0') ++i;
if (i == s.length) {
result = new BigInt();
}
else {
var digitCount = s.length - i;
var fgl = digitCount % dpl10;
if (fgl == 0) fgl = dpl10;
result = RSAUtils.biFromNumber(Number(s.substr(i, fgl)));
i += fgl;
while (i < s.length) {
result = RSAUtils.biAdd(RSAUtils.biMultiply(result, lr10),
RSAUtils.biFromNumber(Number(s.substr(i, dpl10))));
i += dpl10;
}
result.isNeg = isNeg;
}
return result;
};
RSAUtils.biCopy = function(bi) {
var result = new BigInt(true);
result.digits = bi.digits.slice(0);
result.isNeg = bi.isNeg;
return result;
};
RSAUtils.reverseStr = function(s) {
var result = "";
for (var i = s.length - 1; i > -1; --i) {
result += s.charAt(i);
}
return result;
};
var hexatrigesimalToChar = [
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
'u', 'v', 'w', 'x', 'y', 'z'
];
RSAUtils.biToString = function(x, radix) { // 2 <= radix <= 36
var b = new BigInt();
b.digits[0] = radix;
var qr = RSAUtils.biDivideModulo(x, b);
var result = hexatrigesimalToChar[qr[1].digits[0]];
while (RSAUtils.biCompare(qr[0], bigZero) == 1) {
qr = RSAUtils.biDivideModulo(qr[0], b);
digit = qr[1].digits[0];
result += hexatrigesimalToChar[qr[1].digits[0]];
}
return (x.isNeg ? "-" : "") + RSAUtils.reverseStr(result);
};
RSAUtils.biToDecimal = function(x) {
var b = new BigInt();
b.digits[0] = 10;
var qr = RSAUtils.biDivideModulo(x, b);
var result = String(qr[1].digits[0]);
while (RSAUtils.biCompare(qr[0], bigZero) == 1) {
qr = RSAUtils.biDivideModulo(qr[0], b);
result += String(qr[1].digits[0]);
}
return (x.isNeg ? "-" : "") + RSAUtils.reverseStr(result);
};
var hexToChar = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f'];
RSAUtils.digitToHex = function(n) {
var mask = 0xf;
var result = "";
for (i = 0; i < 4; ++i) {
result += hexToChar[n & mask];
n >>>= 4;
}
return RSAUtils.reverseStr(result);
};
RSAUtils.biToHex = function(x) {
var result = "";
var n = RSAUtils.biHighIndex(x);
for (var i = RSAUtils.biHighIndex(x); i > -1; --i) {
result += RSAUtils.digitToHex(x.digits[i]);
}
return result;
};
RSAUtils.charToHex = function(c) {
var ZERO = 48;
var NINE = ZERO + 9;
var littleA = 97;
var littleZ = littleA + 25;
var bigA = 65;
var bigZ = 65 + 25;
var result;
if (c >= ZERO && c <= NINE) {
result = c - ZERO;
} else if (c >= bigA && c <= bigZ) {
result = 10 + c - bigA;
} else if (c >= littleA && c <= littleZ) {
result = 10 + c - littleA;
} else {
result = 0;
}
return result;
};
RSAUtils.hexToDigit = function(s) {
var result = 0;
var sl = Math.min(s.length, 4);
for (var i = 0; i < sl; ++i) {
result <<= 4;
result |= RSAUtils.charToHex(s.charCodeAt(i));
}
return result;
};
RSAUtils.biFromHex = function(s) {
var result = new BigInt();
var sl = s.length;
for (var i = sl, j = 0; i > 0; i -= 4, ++j) {
result.digits[j] = RSAUtils.hexToDigit(s.substr(Math.max(i - 4, 0), Math.min(i, 4)));
}
return result;
};
RSAUtils.biFromString = function(s, radix) {
var isNeg = s.charAt(0) == '-';
var istop = isNeg ? 1 : 0;
var result = new BigInt();
var place = new BigInt();
place.digits[0] = 1; // radix^0
for (var i = s.length - 1; i >= istop; i--) {
var c = s.charCodeAt(i);
var digit = RSAUtils.charToHex(c);
var biDigit = RSAUtils.biMultiplyDigit(place, digit);
result = RSAUtils.biAdd(result, biDigit);
place = RSAUtils.biMultiplyDigit(place, radix);
}
result.isNeg = isNeg;
return result;
};
RSAUtils.biDump = function(b) {
return (b.isNeg ? "-" : "") + b.digits.join(" ");
};
RSAUtils.biAdd = function(x, y) {
var result;
if (x.isNeg != y.isNeg) {
y.isNeg = !y.isNeg;
result = RSAUtils.biSubtract(x, y);
y.isNeg = !y.isNeg;
}
else {
result = new BigInt();
var c = 0;
var n;
for (var i = 0; i < x.digits.length; ++i) {
n = x.digits[i] + y.digits[i] + c;
result.digits[i] = n % biRadix;
c = Number(n >= biRadix);
}
result.isNeg = x.isNeg;
}
return result;
};
RSAUtils.biSubtract = function(x, y) {
var result;
if (x.isNeg != y.isNeg) {
y.isNeg = !y.isNeg;
result = RSAUtils.biAdd(x, y);
y.isNeg = !y.isNeg;
} else {
result = new BigInt();
var n, c;
c = 0;
for (var i = 0; i < x.digits.length; ++i) {
n = x.digits[i] - y.digits[i] + c;
result.digits[i] = n % biRadix;
// Stupid non-conforming modulus operation.
if (result.digits[i] < 0) result.digits[i] += biRadix;
c = 0 - Number(n < 0);
}
// Fix up the negative sign, if any.
if (c == -1) {
c = 0;
for (var i = 0; i < x.digits.length; ++i) {
n = 0 - result.digits[i] + c;
result.digits[i] = n % biRadix;
// Stupid non-conforming modulus operation.
if (result.digits[i] < 0) result.digits[i] += biRadix;
c = 0 - Number(n < 0);
}
// Result is opposite sign of arguments.
result.isNeg = !x.isNeg;
} else {
// Result is same sign.
result.isNeg = x.isNeg;
}
}
return result;
};
RSAUtils.biHighIndex = function(x) {
var result = x.digits.length - 1;
while (result > 0 && x.digits[result] == 0) --result;
return result;
};
RSAUtils.biNumBits = function(x) {
var n = RSAUtils.biHighIndex(x);
var d = x.digits[n];
var m = (n + 1) * bitsPerDigit;
var result;
for (result = m; result > m - bitsPerDigit; --result) {
if ((d & 0x8000) != 0) break;
d <<= 1;
}
return result;
};
RSAUtils.biMultiply = function(x, y) {
var result = new BigInt();
var c;
var n = RSAUtils.biHighIndex(x);
var t = RSAUtils.biHighIndex(y);
var u, uv, k;
for (var i = 0; i <= t; ++i) {
c = 0;
k = i;
for (j =
