Create a canonical JSON string - ideal for cyptographic signing and verifying.

CanonicalJSON.js

function getCanonicalJSON(obj) {
	if(typeof obj === 'object') {
		var keys = [];
		// get keys and sort them
		for(var k in obj) keys.push(k);
		keys.sort();
		
		// append each kvp to string
		return '{' + keys.reduce(function(prev, cur, i) {
			return prev + (i>0?',':'') + '"' + cur + '":' + getCanonicalJSON(obj[cur]);
		}, '') + '}';
	} else if(typeof obj === 'function') {
		return 'null';
	} else return JSON.stringify(obj);
}