Encrypting files with SJCL client-side - javascript

I have problem encrypting files with SJCL and javascript.
I have managed to encrypt text-files with using FileReader API and readAsBinaryString.
When it comes to encrypting pdf/png/.. then problem arrises probably due to encoding.
I found that I can use readAsArrayBuffer which suits this task perfectly, so I basically read file and create new typed array with new Uint8Array() but i dont know how exactly I am supposed to encrypt such a data.
Here's my code:
/** Convert from an array of bytes to a bitArray. */
function toBitArrayCodec(bytes) {
var out = [], i, tmp=0;
for (i=0; i<bytes.length; i++) {
tmp = tmp << 8 | bytes[i];
if ((i&3) === 3) {
out.push(tmp);
tmp = 0;
}
}
if (i&3) {
out.push(sjcl.bitArray.partial(8*(i&3), tmp));
}
return out;
}
/** Convert from a bitArray to an array of bytes. */
function fromBitArrayCodec(arr) {
var out = [], bl = sjcl.bitArray.bitLength(arr), i, tmp;
for (i=0; i<bl/8; i++) {
if ((i&3) === 0) {
tmp = arr[i/4];
}
out.push(tmp >>> 24);
tmp <<= 8;
}
return out;
}
var reader = new FileReader();
reader.readAsArrayBuffer(fileData); //filedata comes from function
reader.onload = function() {
var bytes = new Uint8Array(reader.result);
var bits = toBitArrayCodec(bytes);
var crypt = sjcl.encrypt("aaaaa", bits);
var decrypt = sjcl.decrypt("aaaaa", crypt);
var byteNumbers = fromBitArrayCodec(decrypt);
var byteArray = new Uint8Array(byteNumbers);
saveData(byteArray, 'png.png');
I am getting error on
Uncaught URIError: URI malformed sjcl.js:12sjcl.codec.utf8String.fromBits sjcl.js:12sjcl.json.decrypt sjcl.js:44reader.onload
I need to know how to encrypt uint8array or another alternative how to encrypt(pdf/png/..) files.

The plaintext in sjcl is expected to be utf8 encoded. Encrypting a manually built bitArray works, because the encryption is done on the bitArray and it doesn't have to be decoded. But at the end of the decryption is an encoding step which converts the recovered plaintext bitArray into a utf8string. This doesn't work, because it contains unprintable characters, because the source was probably binary.
The solution would be to encode it as Base64 before encrypting and convert it back after decrypting.
var bytes = new Uint8Array(reader.result);
var bits = toBitArrayCodec(bytes);
var base64bits = sjcl.codec.base64.fromBits(bits); // added
var crypt = sjcl.encrypt("aaaaa", base64bits);
var base64decrypt = sjcl.decrypt("aaaaa", crypt);
var decrypt = sjcl.codec.base64.toBits(base64decrypt); // added
var byteNumbers = fromBitArrayCodec(decrypt);
var byteArray = new Uint8Array(byteNumbers);

Related

Why AEC encryption in .NET yields different result than JavaScript?

I'm going crazy about this one. Spend whole day and still can't understand what is going on. I'm using AES256CBC encryption both in .Net and JavaScript. For some reason I got different results, despite that I'm using same key an iv. My codes are:
JavaScript:
function convertStringToArrayBuffer(str) {
var length = str.length;
var bytes = new Uint8Array(length);
for(var i = 0; i < length; i++) {
bytes[i] = str.charCodeAt(i);
}
return bytes;
}
var keyB64 ="sy/d1Ddy/9K3p8x6pWMq2P8Qw2ftUjkkrAA7xFC7aK8=";
var viB64 = "t8eI2F+QmlUBWZJVIlTX6Q==";
var dataToEnc = "Test123!"
let dataInBytes = convertStringToArrayBuffer(dataToEnc);
let key = window.atob(keyB64);
let iv = window.atob(viB64);
console.log(key);
console.log(iv);
window.crypto.subtle.importKey("raw", convertStringToArrayBuffer(key).buffer, {name: "AES-CBC", length: 256}, false, ["encrypt"]).then(function(key){
console.log(key);
window.crypto.subtle.encrypt({name: "AES-CBC", iv: convertStringToArrayBuffer(iv).buffer}, key, dataInBytes.buffer).then(function(encrypted){
console.log(encrypted);
});
});
This one produces
.Net:
public static void Test()
{
var dataToEnc = "Test123!";
var keyB64 = "sy/d1Ddy/9K3p8x6pWMq2P8Qw2ftUjkkrAA7xFC7aK8=";
var viB64 = "t8eI2F+QmlUBWZJVIlTX6Q==";
var key = Convert.FromBase64String(keyB64);
var iv = Convert.FromBase64String(viB64);
var data = Encoding.UTF8.GetBytes(dataToEnc);
byte[] encrypted = null;
using (Aes aesAlg = Aes.Create())
{
aesAlg.Key = key;
aesAlg.IV = iv;
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
using (MemoryStream msEncrypt = new MemoryStream())
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
swEncrypt.Write(data);
}
encrypted = msEncrypt.ToArray();
}
}
}
}
This one produces
I belive it is something trivial, yet I can't find this. I appreciate any hint here.
If anyone else is having this issue #Topaco's comment is right way to go, I'm pasting it below
The bug is in the C# code. You have to use swEncrypt.Write(dataToEnc) instead of swEncrypt.Write(data). The overload you are currently using implicitly executes data.ToString()

Convert xlsx (byte array) to csv(string) with javascript

I am from c# so know nothing about java script.
I have excel file (xlsx) that I red into byte array (with unity3d c# in webGL build) and want to send it into java script function that parse it into csv structure and return as string.
So the question part is only related to java script that received xlsx as byte array(or any type from memory stream) and return csv as string.
I need that function. What else (libs) do I need for that?
(Update)
The javascript code is
MyConverterXlsxToCsvReturn: function (array,size) {
var buffer = new ArrayBuffer(size);
for (var i = 0; i < size; i++)
buffer[i] = HEAPU8[array + i];
var txt = XLSX.utils.sheet_to_txt(buffer, {type: 'arraybuffer'});
window.alert(Pointer_stringify(txt));
window.alert(Pointer_stringify(txt.length));
var returnStr = Pointer_stringify(txt);
var bufferSize = lengthBytesUTF8(returnStr) + 1;
var buffer = _malloc(bufferSize);
stringToUTF8(returnStr, buffer, bufferSize);
return buffer;
},
I am trying to send byte[] and convert into arraybuffer but in search of correct way to do that.
For now that function return empty string.
I wanted to convert byte array that I received in C# and then red the array in javascript.
As solution I converted the the byte array into hex string with method:
private string ByteArrayToString(byte[] ba)
{
StringBuilder hex = new StringBuilder(ba.Length * 2);
foreach (byte b in ba)
hex.AppendFormat("{0:x2}", b);
return hex.ToString();
}
Then this string i sent to javascript function and converted to array. The rezult was returned as string:
ExcelHexToCSV: function (hexStr) {
console.log("javascript: ExcelHexToCSV");
console.log("javascript received: " + Pointer_stringify(hexStr));
// convert part
var str = Pointer_stringify(hexStr);
var a = [];
for (var i = 0, len = str.length; i < len; i += 2) {
a.push(parseInt(str.substr(i, 2), 16));
}
var data = new Uint8Array(a);
console.log("javascript hex_to_byte:" + data);
// excel part
var workbook = XLSX.read(data, {type: "array"});
var sheetname = workbook.SheetNames[0];
console.log("javascript sheetname: " + sheetname);
var sheetdata = XLSX.utils.sheet_to_csv(workbook.Sheets[sheetname]);
console.log("javascript sheetdata: = " + sheetdata);
var rezult = sheetdata;
var returnStr = rezult;
var bufferSize = lengthBytesUTF8(returnStr) + 1;
var buffer = _malloc(bufferSize);
stringToUTF8(returnStr, buffer, bufferSize);
return buffer;
},
Github link for the my example project

Java SHA-1 to javascript using CryptoJS

i have such a code to generate password written in Java
MessageDigest messageDigestPassword = MessageDigest.getInstance("SHA1");
messageDigestPassword .reset();
byte[] password = "password".getBytes();
messageDigestPassword .update(password);
byte[] encryptedPassword = messageDigestPassword .digest();
String date = "2019-10-22T11:33:13.393Z";
byte[] dateBytes = date.getBytes(StandardCharsets.UTF_8);
int offset = 0;
byte[] outputBytes = new byte[dateBytes.length + encryptedPassword .length];
System.arraycopy(dateBytes, 0, outputBytes, offset, dateBytes.length);
offset += dateBytes.length;
System.arraycopy(encryptedPassword , 0, outputBytes, offset, encryptedPassword .length);
MessageDigest finalMessageDigeset = MessageDigest.getInstance("SHA-1");
finalMessageDigeset.reset();
finalMessageDigeset.update(outputBytes);
byte[] finalPasswordBytes= finalMessageDigeset .digest();
String finalBase64Password = new String(Base64.encode(finalPasswordBytes));
and im trying to rewrite it to JavaScript to use it in postman with - CryptoJS
So far i have :
function wordArrayToByteArray(wordArray, length) {
if (wordArray.hasOwnProperty("sigBytes") &&
wordArray.hasOwnProperty("words")) {
length = wordArray.sigBytes;
wordArray = wordArray.words;
}
var result = [],
bytes,
i = 0;
while (length > 0) {
bytes = wordToByteArray(wordArray[i], Math.min(4, length));
length -= bytes.length;
result.push(bytes);
i++;
}
return [].concat.apply([], result);
}
function stringToBytes ( str ) {
var ch, st, re = [];
for (var i = 0; i < str.length; i++ ) {
ch = str.charCodeAt(i); // get char
st = []; // set up "stack"
do {
st.push( ch & 0xFF ); // push byte to stack
ch = ch >> 8; // shift value down by 1 byte
}
while ( ch );
// add stack contents to result
// done because chars have "wrong" endianness
re = re.concat( st.reverse() );
}
// return an array of bytes
return re;
}
var dateFixed = "2019-10-22T11:33:13.393Z";
var fixedDateBytes = stringToBytes(dateFixed);
var sha1Password= CryptoJS.SHA1("password");
console.log("sha1Password",sha1Password.toString(CryptoJS.enc.Hex));
var sha1PasswordBytes= wordArrayToByteArray(sha1Password, 20);
var concatedBytes= fixedDateBytes.concat(sha1PasswordBytes);
var finalShaPassWords= CryptoJS.SHA1(concatedBytes);
console.log("finalShaPassWords",finalShaPassWords.toString(CryptoJS.enc.Hex));
console.log("finalShaPassWords",finalShaPassWords.toString(CryptoJS.enc.Base64));
However unfortunatelly Base64 representations written in those 2 languages doesnt match.
I have checked and bytes from date are equal. Bytes from hashed password are not. So hashing after concat fails in JavaScript.
I have checked first password hashing and generated bytes and both of them are the same. So my guess line var sha1PasswordBytes= wordArrayToByteArray(sha1Password, 20); causes that line var finalShaPassWords= CryptoJS.SHA1(concatedBytes); returns bad value.
Can someone give me some idea what is wrong? Mayby it should be written diffrent ?
Since you are using CryptoJS anyway, you can also use the CryptoJS encoders and the WordArray#concat-method, which considerably simplifies the code:
var CryptoJS = require("crypto-js");
// Input
var inPwd = "password";
var inDate = "2019-10-22T11:33:13.393Z";
// Processing
var pwdHash = CryptoJS.SHA1(inPwd); // hash and convert to WordArray
var date = CryptoJS.enc.Utf8.parse(inDate); // convert to WordArray
var joinedData = date.clone().concat(pwdHash); // join date and hashed password
var joinedDataHash = CryptoJS.SHA1(joinedData); // hash joined data
var joinedDataHashB64 = CryptoJS.enc.Base64.stringify(joinedDataHash); // convert to Base64 string
// Output
console.log("Result: " + joinedDataHashB64 ); // Output: D235TBTZMfpSyB/CDl5MHAjH5fI=
The output of this code is the same as the output of the Java-code: D235TBTZMfpSyB/CDl5MHAjH5fI=

how to open base64 String response from server in external viewer (viewer.html) using pdf.js?

In my application i am sending a path to the server and which returns me a pdf file contents in base64 string. Now i want to show this string in external viewer (viewer.html) using pdf.js. I am doing in this in following way, what wrong am i doing?
var res="JVBERi0xLjUK..."; // Base64 String from response shortened
var pdfData = base64ToUint8Array(res);
window.open('pdfJs/viewer.html?file='+pdfData);
function base64ToUint8Array(base64) {
var raw = atob(base64); //This is a native function that decodes a base64-encoded string.
var uint8Array = new Uint8Array(new ArrayBuffer(raw.length));
for(var i = 0; i < raw.length; i++) {
uint8Array[i] = raw.charCodeAt(i);
}
return uint8Array;
}
Output i am getting now:
I have gone through some of answers but cant sort it out. So please help me.
The Uint8Array cannot be passed via query string. Use PDFViewerApplication.open() method on the opened window, e.g.
var w = window.open('web/viewer.html?file=');
w.addEventListener('load', function () {
var res="JVBERi0xLjUK..."; // Base64 String from response shortened
var pdfData = base64ToUint8Array(res);
w.PDFViewerApplication.open(pdfData);
function base64ToUint8Array(base64) {
var raw = atob(base64);
var uint8Array = new Uint8Array(raw.length);
for(var i = 0; i < raw.length; i++) {
uint8Array[i] = raw.charCodeAt(i);
}
return uint8Array;
}
}, true);

ArrayBuffer to base64 encoded string

I need an efficient (read native) way to convert an ArrayBuffer to a base64 string which needs to be used on a multipart post.
function _arrayBufferToBase64( buffer ) {
var binary = '';
var bytes = new Uint8Array( buffer );
var len = bytes.byteLength;
for (var i = 0; i < len; i++) {
binary += String.fromCharCode( bytes[ i ] );
}
return window.btoa( binary );
}
but, non-native implementations are faster e.g. https://gist.github.com/958841
see http://jsperf.com/encoding-xhr-image-data/6
Updated benchmarks: https://jsben.ch/wnaZC
This works fine for me:
var base64String = btoa(String.fromCharCode.apply(null, new Uint8Array(arrayBuffer)));
In ES6, the syntax is a little simpler:
const base64String = btoa(String.fromCharCode(...new Uint8Array(arrayBuffer)));
As pointed out in the comments, this method may result in a runtime error in some browsers when the ArrayBuffer is large. The exact size limit is implementation dependent in any case.
For those who like it short, here's an other one using Array.reduce which will not cause stack overflow:
var base64 = btoa(
new Uint8Array(arrayBuffer)
.reduce((data, byte) => data + String.fromCharCode(byte), '')
);
There is another asynchronous way use Blob and FileReader.
I didn't test the performance. But it is a different way of thinking.
function arrayBufferToBase64( buffer, callback ) {
var blob = new Blob([buffer],{type:'application/octet-binary'});
var reader = new FileReader();
reader.onload = function(evt){
var dataurl = evt.target.result;
callback(dataurl.substr(dataurl.indexOf(',')+1));
};
reader.readAsDataURL(blob);
}
//example:
var buf = new Uint8Array([11,22,33]);
arrayBufferToBase64(buf, console.log.bind(console)); //"CxYh"
const blob = new Blob([array]);
const reader = new FileReader();
reader.onload = (event) => {
const dataUrl = event.target.result;
const [_, base64] = dataUrl.split(',');
// do something with base64
};
reader.readAsDataURL(blob);
Or as a promisified utility:
async function encode(array) {
return new Promise((resolve) => {
const blob = new Blob([array]);
const reader = new FileReader();
reader.onload = (event) => {
const dataUrl = event.target.result;
const [_, base64] = dataUrl.split(',');
resolve(base64);
};
reader.readAsDataURL(blob);
});
}
const encoded = await encode(typedArray);
The OP did not specify the Running Enviroment but if you are using Node.JS there is a very simple way to do such thing.
Accordig with the official Node.JS docs
https://nodejs.org/api/buffer.html#buffer_buffers_and_character_encodings
// This step is only necessary if you don't already have a Buffer Object
const buffer = Buffer.from(yourArrayBuffer);
const base64String = buffer.toString('base64');
Also, If you are running under Angular for example, the Buffer Class will also be made available in a Browser Environment.
My recommendation for this is to NOT use native btoa strategies—as they don't correctly encode all ArrayBuffer's…
rewrite the DOMs atob() and btoa()
Since DOMStrings are 16-bit-encoded strings, in most browsers calling window.btoa on a Unicode string will cause a Character Out Of Range exception if a character exceeds the range of a 8-bit ASCII-encoded character.
While I have never encountered this exact error, I have found that many of the ArrayBuffer's I have tried to encode have encoded incorrectly.
I would either use MDN recommendation or gist.
https://github.com/beatgammit/base64-js
https://gist.github.com/jonleighton/958841
I used this and works for me.
function arrayBufferToBase64( buffer ) {
var binary = '';
var bytes = new Uint8Array( buffer );
var len = bytes.byteLength;
for (var i = 0; i < len; i++) {
binary += String.fromCharCode( bytes[ i ] );
}
return window.btoa( binary );
}
function base64ToArrayBuffer(base64) {
var binary_string = window.atob(base64);
var len = binary_string.length;
var bytes = new Uint8Array( len );
for (var i = 0; i < len; i++) {
bytes[i] = binary_string.charCodeAt(i);
}
return bytes.buffer;
}
Below are 2 simple functions for converting Uint8Array to Base64 String and back again
arrayToBase64String(a) {
return btoa(String.fromCharCode(...a));
}
base64StringToArray(s) {
let asciiString = atob(s);
return new Uint8Array([...asciiString].map(char => char.charCodeAt(0)));
}
If you're okay with adding a library, base64-arraybuffer:
yarn add base64-arraybuffer
then:
encode(buffer) - Encodes ArrayBuffer into base64 string
decode(str) - Decodes base64 string to ArrayBuffer
This worked for me:
Buffer.from(myArrayBuffer).toString("base64");
ABtoB64(ab) {
return new Promise(res => {
const fr = new FileReader();
fr.onload = ({target: {result: s}}) => res(s.slice(s.indexOf(';base64,') + 8));
fr.readAsDataURL(new Blob([ab]));
});
}
asynchronous method using file reader.
You can derive a normal array from the ArrayBuffer by using Array.prototype.slice.
Use a function like Array.prototype.map to convert bytes in to characters and join them together to forma string.
function arrayBufferToBase64(ab){
var dView = new Uint8Array(ab); //Get a byte view
var arr = Array.prototype.slice.call(dView); //Create a normal array
var arr1 = arr.map(function(item){
return String.fromCharCode(item); //Convert
});
return window.btoa(arr1.join('')); //Form a string
}
This method is faster since there are no string concatenations running in it.
In the Browser suggested solutions with btoa seem fine.
But in Node.js btoa is deprecated
It is recommended to use buffer.toString(encoding)
like
const myString = buffer.toString("base64")
i use TextDecode api to convert it to normal text and then convert it to Base64
const uint = new Uint8Array([ 73, 32, 108, 111, 118, 101, 32, 121, 111, 117 ]).buffer
const decoder = new TextDecoder()
const decodedText = decoder.decode(uint)
const base64Code = btoa(decodedText)
Use uint8-to-b64 package to do encoding/decoding in browser and Node.js
By my side, using Chrome navigator, I had to use DataView() to read an arrayBuffer
function _arrayBufferToBase64( tabU8A ) {
var binary = '';
let lecteur_de_donnees = new DataView(tabU8A);
var len = lecteur_de_donnees.byteLength;
var chaine = '';
var pos1;
for (var i = 0; i < len; i++) {
binary += String.fromCharCode( lecteur_de_donnees.getUint8( i ) );
}
chaine = window.btoa( binary )
return chaine;}
function _arrayBufferToBase64(uarr) {
var strings = [], chunksize = 0xffff;
var len = uarr.length;
for (var i = 0; i * chunksize < len; i++){
strings.push(String.fromCharCode.apply(null, uarr.subarray(i * chunksize, (i + 1) * chunksize)));
}
return strings.join("");
}
This is better, if you use JSZip for unpack archive from string

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