Javascript Data Utilities

base64EncodeBytes.js

/*
	Converts byte array -> base64 encoded string
*/
function base64EncodeBytes (aBytes)
{
  function uint6ToB64 (nUint6)
  {
    return nUint6 < 26 ?
      nUint6 + 65
      : nUint6 < 52 ?
        nUint6 + 71
      : nUint6 < 62 ?
        nUint6 - 4
      : nUint6 === 62 ?
        43
      : nUint6 === 63 ?
        47
      :
        65;
  }
  var nMod3 = 2, sB64Enc = "";

  for (var nLen = aBytes.length, nUint24 = 0, nIdx = 0; nIdx < nLen; nIdx++)
  {
    nMod3 = nIdx % 3;
    if (nIdx > 0 && (nIdx * 4 / 3) % 76 === 0) { sB64Enc += "\r\n"; }
    nUint24 |= aBytes[nIdx] << (16 >>> nMod3 & 24);
    if (nMod3 === 2 || aBytes.length - nIdx === 1)
    {
      sB64Enc += String.fromCharCode(uint6ToB64(nUint24 >>> 18 & 63), uint6ToB64(nUint24 >>> 12 & 63), uint6ToB64(nUint24 >>> 6 & 63), uint6ToB64(nUint24 & 63));
      nUint24 = 0;
    }
  }
  return sB64Enc.substr(0, sB64Enc.length - 2 + nMod3) + (nMod3 === 2 ? '' : nMod3 === 1 ? '=' : '==');
}

bytesToUTF8.js

// http://www.onicos.com/staff/iz/amuse/javascript/expert/utf.txt

/* utf.js
 *
 * Copyright (C) 1999 Masanao Izumo <[email protected]>
 * Version: 1.0
 * LastModified: Dec 25 1999
 * This library is free.  You can redistribute it and/or modify it.
 */
function bytesToUTF8(array)
{
	var out, i, len, c;
	var char2, char3;
	
	out = "";
	len = array.length;
	i = 0;
	while(i < len)
	{
		c = array[i++];
		switch(c >> 4)
		{ 
		case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
			// 0xxxxxxx
			out += String.fromCharCode(c);
			break;
		case 12: case 13:
			// 110x xxxx   10xx xxxx
			char2 = array[i++];
			out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
			break;
		case 14:
			// 1110 xxxx  10xx xxxx  10xx xxxx
			char2 = array[i++];
			char3 = array[i++];
			out += String.fromCharCode(((c & 0x0F) << 12) | ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0));
			break;
		}
	}
	return out;
}

getImageData.js

/*
 * Read image data from an IMG element
 *
 * imageFormat: e.g. image/png
 * quality: used for image formats like JPEG
 * outputFormat: dataURL | base64 | binary | bytes | blob
 */
$.fn.getImageData = function(outputFormat, imageFormat, quality)
	{
	if (!this.is('img'))
		{
		return null;
		}
	else
		{
		var img = this.get(0);
	
		// Create an empty canvas element
		var canvas = document.createElement("canvas");
		canvas.width = img.width;
		canvas.height = img.height;
		
		// Copy the image contents to the canvas
		var ctx = canvas.getContext("2d");
		ctx.drawImage(img, 0, 0);
		
		if (!imageFormat) imageFormat = "image/png";

		var dataUrl = canvas.toDataURL(imageFormat, quality);
		if (outputFormat == 'dataURL') return dataUrl;
		
		var b64 = dataUrl.replace(/^data:[\w\/]+;base64,/, "");
		if (outputFormat == 'base64') return b64;
		
		var binStr = atob(b64);
		if (outputFormat == 'binary') return binStr;
		
		function TSStringToBytes(str) { var bytes = new Uint8Array(str.length); for (var i=0; i<str.length; i++) bytes[i] = str.charCodeAt(i); return bytes; }
		var bytes = TSStringToBytes(binStr);
		if (outputFormat == 'bytes') return bytes;
		
		return new Blob([bytes], {type:imageFormat});
		}
	}

hex2bin.js

function hex2bin(hex)
  {
  if (!hex) return null;
  hex = hex.replace(/\s/g, '');
  
	var bytes = [];
	for(var i=0; i< hex.length-1; i+=2) { bytes.push(parseInt(hex.substr(i, 2), 16)); }
	return String.fromCharCode.apply(String, bytes);    
  }

hexToArray.js

function hexToArray(hex)
	{
	if (!hex) return null;
	hex = hex.replace(/\s/g, '');
	
	var n = hex.length / 2;
	var arr = new Uint8Array(n);
	for (var i=0; i<n; i++) { arr[i] = parseInt(hex.substr(i*2, 2), 16); }
	return arr;
	}

rc4.js

/*
 * RC4 symmetric cipher encryption/decryption
 *
 * @license Public Domain
 * @param string key - secret key for encryption/decryption
 * @param string str - string to be encrypted/decrypted
 * @return string
 */
function rc4(key, str)
{
	var s = [], j = 0, x, res = [];
	for (var i = 0; i < 256; i++) {
		s[i] = i;
	}
	for (i = 0; i < 256; i++) {
		j = (j + s[i] + key.charCodeAt(i % key.length)) % 256;
		x = s[i];
		s[i] = s[j];
		s[j] = x;
	}
	i = 0;
	j = 0;
	for (var y = 0; y < str.length; y++) {
		i = (i + 1) % 256;
		j = (j + s[i]) % 256;
		x = s[i];
		s[i] = s[j];
		s[j] = x;
		res.push(str.charCodeAt(y) ^ s[(s[i] + s[j]) % 256]);
	}
	return res;
}

TSDataUtils.js

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