gPass/firefox_addon/lib/pkdbf2.js

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/*
Copyright (C) 2013 Grégory Soutadé
This file is part of gPass.
gPass is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
gPass is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with gPass. If not, see <http://www.gnu.org/licenses/>.
*/
var {Cc, Ci} = require("chrome");
var hmac = Cc["@mozilla.org/security/hmac;1"]
.createInstance(Ci.nsICryptoHMAC);
function hmac_init(key) {
var keyObject = Cc["@mozilla.org/security/keyobjectfactory;1"]
.getService(Ci.nsIKeyObjectFactory)
.keyFromString(Ci.nsIKeyObject.HMAC, key);
hmac.init(hmac.SHA256, keyObject);
}
function hmac_digest(message) {
var data = new Uint8Array(message.length);
for(i=0; i<message.length; i++)
data[i] = message.charCodeAt(i);
hmac.update(data, data.length);
res = hmac.finish(false);
hmac.reset();
return res;
}
exports.pkdbf2 = {
pkdbf2 : function(password, salt, iterations, outlen) {
var result = "";
var temp = "";
var temp2 = "";
var temp_res = "";
var temp_res2 = "";
hmac_init(password);
for (i=1; result.length < outlen; i++)
{
temp = hmac_digest(salt +
String.fromCharCode((i & 0xff000000) >> 24) +
String.fromCharCode((i & 0x00ff0000) >> 16) +
String.fromCharCode((i & 0x0000ff00) >> 8) +
String.fromCharCode((i & 0x000000ff) >> 0)
);
temp_res = temp;
for(a=1; a<iterations; a++)
{
temp2 = hmac_digest(temp);
temp_res2 = "";
for(b = 0; b<temp_res.length; b++)
temp_res2 += String.fromCharCode(temp_res.charCodeAt(b) ^ temp2.charCodeAt(b));
temp_res = temp_res2;
temp = temp2;
}
result += temp_res;
}
return result.substr(0, outlen);
}
};