ds_mobile_app/mobile/utils/base.js

	export function weBtoa(string){
		var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
		b64re = /^(?:[A-Za-z\d+\/]{4})*?(?:[A-Za-z\d+\/]{2}(?:==)?|[A-Za-z\d+\/]{3}=?)?$/;
		string = String(string);
		var bitmap, a, b, c,
		    result = "",
		    i = 0,
		    rest = string.length % 3; // To determine the final padding
		
		for (; i < string.length;) {
		    if ((a = string.charCodeAt(i++)) > 255 ||
		        (b = string.charCodeAt(i++)) > 255 ||
		        (c = string.charCodeAt(i++)) > 255)
		        throw new TypeError("Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the Latin1 range.");
		
		    bitmap = (a << 16) | (b << 8) | c;
		    result += b64.charAt(bitmap >> 18 & 63) + b64.charAt(bitmap >> 12 & 63) +
		        b64.charAt(bitmap >> 6 & 63) + b64.charAt(bitmap & 63);
		}
		
		// If there's need of padding, replace the last 'A's with equal signs
		return rest ? result.slice(0, rest - 3) + "===".substring(rest) : result;
	}
	
	export function weAtob(string){
		// atob can work with strings with whitespaces, even inside the encoded part,
		// but only \t, \n, \f, \r and ' ', which can be stripped.
		var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
		b64re = /^(?:[A-Za-z\d+\/]{4})*?(?:[A-Za-z\d+\/]{2}(?:==)?|[A-Za-z\d+\/]{3}=?)?$/;
		string = String(string).replace(/[\t\n\f\r ]+/g, "");
		if (!b64re.test(string))
		    throw new TypeError("Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.");
		
		// Adding the padding if missing, for semplicity
		string += "==".slice(2 - (string.length & 3));
		var bitmap, result = "",
		    r1, r2, i = 0;
		for (; i < string.length;) {
		    bitmap = b64.indexOf(string.charAt(i++)) << 18 | b64.indexOf(string.charAt(i++)) << 12 |
		        (r1 = b64.indexOf(string.charAt(i++))) << 6 | (r2 = b64.indexOf(string.charAt(i++)));
		
		    result += r1 === 64 ? String.fromCharCode(bitmap >> 16 & 255) :
		        r2 === 64 ? String.fromCharCode(bitmap >> 16 & 255, bitmap >> 8 & 255) :
		        String.fromCharCode(bitmap >> 16 & 255, bitmap >> 8 & 255, bitmap & 255);
		}
		return result;
	}