Signal-Desktop/libtextsecure/helpers.js

116 lines
3.7 KiB
JavaScript

/*
* vim: ts=4:sw=4:expandtab
*/
window.textsecure = window.textsecure || {};
/*********************************
*** Type conversion utilities ***
*********************************/
// Strings/arrays
//TODO: Throw all this shit in favor of consistent types
//TODO: Namespace
var StaticByteBufferProto = new dcodeIO.ByteBuffer().__proto__;
var StaticArrayBufferProto = new ArrayBuffer().__proto__;
var StaticUint8ArrayProto = new Uint8Array().__proto__;
function getString(thing) {
if (thing === Object(thing)) {
if (thing.__proto__ == StaticUint8ArrayProto)
return String.fromCharCode.apply(null, thing);
if (thing.__proto__ == StaticArrayBufferProto)
return getString(new Uint8Array(thing));
if (thing.__proto__ == StaticByteBufferProto)
return thing.toString("binary");
}
return thing;
}
function getStringable(thing) {
return (typeof thing == "string" || typeof thing == "number" || typeof thing == "boolean" ||
(thing === Object(thing) &&
(thing.__proto__ == StaticArrayBufferProto ||
thing.__proto__ == StaticUint8ArrayProto ||
thing.__proto__ == StaticByteBufferProto)));
}
function isEqual(a, b, mayBeShort) {
// TODO: Special-case arraybuffers, etc
if (a === undefined || b === undefined)
return false;
a = getString(a);
b = getString(b);
var maxLength = mayBeShort ? Math.min(a.length, b.length) : Math.max(a.length, b.length);
if (maxLength < 5)
throw new Error("a/b compare too short");
return a.substring(0, Math.min(maxLength, a.length)) == b.substring(0, Math.min(maxLength, b.length));
}
function toArrayBuffer(thing) {
//TODO: Optimize this for specific cases
if (thing === undefined)
return undefined;
if (thing === Object(thing) && thing.__proto__ == StaticArrayBufferProto)
return thing;
if (thing instanceof Array) {
// Assuming Uint16Array from curve25519
var res = new ArrayBuffer(thing.length * 2);
var uint = new Uint16Array(res);
for (var i = 0; i < thing.length; i++)
uint[i] = thing[i];
return res;
}
if (!getStringable(thing))
throw new Error("Tried to convert a non-stringable thing of type " + typeof thing + " to an array buffer");
var str = getString(thing);
var res = new ArrayBuffer(str.length);
var uint = new Uint8Array(res);
for (var i = 0; i < str.length; i++)
uint[i] = str.charCodeAt(i);
return res;
}
// Number formatting utils
window.textsecure.utils = function() {
var self = {};
self.unencodeNumber = function(number) {
return number.split(".");
};
self.isNumberSane = function(number) {
return number[0] == "+" &&
/^[0-9]+$/.test(number.substring(1));
}
/**************************
*** JSON'ing Utilities ***
**************************/
function ensureStringed(thing) {
if (getStringable(thing))
return getString(thing);
else if (thing instanceof Array) {
var res = [];
for (var i = 0; i < thing.length; i++)
res[i] = ensureStringed(thing[i]);
return res;
} else if (thing === Object(thing)) {
var res = {};
for (var key in thing)
res[key] = ensureStringed(thing[key]);
return res;
} else if (thing === null) {
return null;
}
throw new Error("unsure of how to jsonify object of type " + typeof thing);
}
self.jsonThing = function(thing) {
return JSON.stringify(ensureStringed(thing));
}
return self;
}();