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implementing web crypto API for encryption

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This commit is contained in:
El RIDO
2018-09-01 19:42:22 +02:00
parent bd6888687f
commit 0dbbb61d11
10 changed files with 280 additions and 80 deletions
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1
js/common.js
View File

@@ -6,6 +6,7 @@ global.jsc = require('jsverify');
global.jsdom = require('jsdom-global');
global.cleanup = global.jsdom();
global.fs = require('fs');
global.WebCrypto = require('node-webcrypto-ossl');
// application libraries to test
global.$ = global.jQuery = require('./jquery-3.3.1');

43
js/package.json Normal file
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@@ -0,0 +1,43 @@
{
"name": "privatebin",
"version": "1.2.1",
"description": "PrivateBin is a minimalist, open source online pastebin where the server has zero knowledge of pasted data. Data is encrypted/decrypted in the browser using 256 bit AES in Galois Counter mode (GCM).",
"main": "privatebin.js",
"directories": {
"test": "test"
},
"dependencies": {},
"devDependencies": {
"jsdom": "^9.12.0",
"jsdom-global": "^2.1.1",
"jsverify": "^0.8.3",
"mime-types": "^2.1.20",
"node-webcrypto-ossl": "^1.0.37"
},
"scripts": {
"test": "mocha"
},
"repository": {
"type": "git",
"url": "git+https://github.com/PrivateBin/PrivateBin.git"
},
"keywords": [
"private",
"secure",
"end-to-end-encrypted",
"e2e",
"paste",
"pastebin",
"zero",
"zero-knowledge",
"encryption",
"encrypted",
"AES"
],
"author": "",
"license": "zlib-acknowledgement",
"bugs": {
"url": "https://github.com/PrivateBin/PrivateBin/issues"
},
"homepage": "https://privatebin.info/"
}

266
js/privatebin.js
View File

@@ -526,6 +526,30 @@ jQuery.PrivateBin = (function($, sjcl, RawDeflate) {
var CryptTool = (function () {
var me = {};
/**
* convert UTF-8 string stored in a DOMString to a standard UTF-16 DOMString
*
* Iterates over the bytes of the message, converting them all hexadecimal
* percent encoded representations, then URI decodes them all
*
* @name CryptTool.btou
* @function
* @private
* @param {string} message UTF-8 string
* @return {string} UTF-16 string
*/
function btou(message)
{
return decodeURIComponent(
message.split('').map(
function(character)
{
return '%' + ('00' + character.charCodeAt(0).toString(16)).slice(-2);
}
).join('')
);
}
/**
* convert DOMString (UTF-16) to a UTF-8 string stored in a DOMString
*
@@ -550,27 +574,49 @@ jQuery.PrivateBin = (function($, sjcl, RawDeflate) {
}
/**
* convert UTF-8 string stored in a DOMString to a standard UTF-16 DOMString
* convert ArrayBuffer into a UTF-8 string
*
* Iterates over the bytes of the message, converting them all hexadecimal
* percent encoded representations, then URI decodes them all
* Iterates over the bytes of the array, catenating them into a string
*
* @name CryptTool.btou
* @name CryptTool.ArrToStr
* @function
* @private
* @param {ArrayBuffer} messageArray
* @return {string} message
*/
function ArrToStr(messageArray)
{
var array = new Uint8Array(messageArray),
len = array.length,
message = '',
i = 0;
while(i < len) {
var c = array[i++];
message += String.fromCharCode(c);
}
return message;
}
/**
* convert UTF-8 string into a Uint8Array
*
* Iterates over the bytes of the message, writing them to the array
*
* @name CryptTool.StrToArr
* @function
* @private
* @param {string} message UTF-8 string
* @return {string} UTF-16 string
* @return {Uint8Array} array
*/
function btou(message)
function StrToArr(message)
{
return decodeURIComponent(
message.split('').map(
function(character)
{
return '%' + ('00' + character.charCodeAt(0).toString(16)).slice(-2);
}
).join('')
);
var messageUtf8 = message,
messageLen = messageUtf8.length,
messageArray = new Uint8Array(messageLen);
for (var i = 0; i < messageLen; ++i) {
messageArray[i] = messageUtf8.charCodeAt(i);
}
return messageArray;
}
/**
@@ -611,6 +657,42 @@ jQuery.PrivateBin = (function($, sjcl, RawDeflate) {
}
}
/**
* returns specified number of random bytes
*
* @name CryptTool.getRandomBytes
* @function
* @private
* @param {int} length number of random bytes to fetch
* @throws {string}
* @return {string} random bytes
*/
function getRandomBytes(length)
{
if (
typeof window !== 'undefined' &&
typeof Uint8Array !== 'undefined' &&
String.fromCodePoint &&
(
typeof window.crypto !== 'undefined' ||
typeof window.msCrypto !== 'undefined'
)
) {
// modern browser environment
var bytes = '',
byteArray = new Uint8Array(length),
crypto = window.crypto || window.msCrypto;
crypto.getRandomValues(byteArray);
for (var i = 0; i < length; ++i) {
bytes += String.fromCharCode(byteArray[i]);
}
return bytes;
} else {
// legacy browser or unsupported environment
throw 'No supported crypto API detected, you may read pastes and comments, but can\'t create pastes or add new comments.';
}
};
/**
* compress, then encrypt message with given key and password
*
@@ -621,19 +703,68 @@ jQuery.PrivateBin = (function($, sjcl, RawDeflate) {
* @param {string} message
* @return {string} data - JSON with encrypted data
*/
me.cipher = function(key, password, message)
me.cipher = async function(key, password, message)
{
// Galois Counter Mode, keysize 256 bit, authentication tag 128 bit
var options = {
mode: 'gcm',
ks: 256,
ts: 128
};
// AES in Galois Counter Mode, keysize 256 bit, authentication tag 128 bit, 10000 iterations in key derivation
var iv = getRandomBytes(16),
salt = getRandomBytes(8),
object = {
iv: btoa(iv),
v: 1,
iter: 10000,
ks: 256,
ts: 128,
mode: 'gcm',
adata: '', // if used, base64 encode it with btoa()
cipher: 'aes',
salt: btoa(salt)
},
algo = 'AES-' + object.mode.toUpperCase();
if ((password || '').trim().length === 0) {
return sjcl.encrypt(key, compress(message), options);
if ((password || '').trim().length > 0) {
key += sjcl.codec.hex.fromBits(sjcl.hash.sha256.hash(password));
}
return sjcl.encrypt(key + sjcl.codec.hex.fromBits(sjcl.hash.sha256.hash(password)), compress(message), options);
// import raw key
var importedKey = await window.crypto.subtle.importKey(
'raw', // only 'raw' is allowed
StrToArr(key),
{name: 'PBKDF2'}, // we use PBKDF2 for key derivation
false, // the key may not be exported
["deriveKey"] // we may only use it for key derivation
)
// derive a stronger key for use with AES
var derivedKey = await window.crypto.subtle.deriveKey(
{
name: 'PBKDF2', // we use PBKDF2 for key derivation
salt: StrToArr(atob(object.salt)), // salt used in HMAC
iterations: object.iter, // amount of iterations to apply
hash: {name: "SHA-256"}, // can be "SHA-1", "SHA-256", "SHA-384" or "SHA-512"
},
importedKey,
{
// can be any supported AES algorithm ("AES-CTR", "AES-CBC", "AES-CMAC", "AES-GCM", "AES-CFB", "AES-KW", "ECDH", "DH" or "HMAC")
name: algo,
length: object.ks, // can be 128, 192 or 256
},
false, // the key may not be exported
["encrypt"] // we may only use it for decryption
)
// finally, encrypt message
var encrypted = await window.crypto.subtle.encrypt(
{
// can be any supported AES algorithm ("AES-CTR", "AES-CBC", "AES-CMAC", "AES-GCM", "AES-CFB", "AES-KW", "ECDH", "DH" or "HMAC")
name: algo,
iv: StrToArr(atob(object.iv)), // the initialization vector you used to encrypt
additionalData: StrToArr(atob(object.adata)), // the addtional data you used during encryption (if any)
tagLength: object.ts, // the length of the tag you used to encrypt (if any)
},
derivedKey,
StrToArr(compress(message)) // compressed plain text to encrypt
)
return btoa(ArrToStr(encrypted));
};
/**
@@ -646,18 +777,57 @@ jQuery.PrivateBin = (function($, sjcl, RawDeflate) {
* @param {string} data - JSON with encrypted data
* @return {string} decrypted message, empty if decryption failed
*/
me.decipher = function(key, password, data)
me.decipher = async function(key, password, data)
{
if (data !== undefined) {
try {
return decompress(sjcl.decrypt(key, data));
} catch(err) {
try {
return decompress(sjcl.decrypt(key + sjcl.codec.hex.fromBits(sjcl.hash.sha256.hash(password)), data));
} catch(e) {
return '';
}
try {
if (password.length > 0) {
key += sjcl.codec.hex.fromBits(sjcl.hash.sha256.hash(password));
}
var object = JSON.parse(data),
algo = 'AES-' + object.mode.toUpperCase();
// import raw key
var importedKey = await window.crypto.subtle.importKey(
'raw', // only 'raw' is allowed
StrToArr(key),
{name: 'PBKDF2'}, // we use PBKDF2 for key derivation
false, // the key may not be exported
["deriveKey"] // we may only use it for key derivation
)
// derive a stronger key for use with AES
var derivedKey = await window.crypto.subtle.deriveKey(
{
name: 'PBKDF2', // we use PBKDF2 for key derivation
salt: StrToArr(atob(object.salt)), // salt used in HMAC
iterations: object.iter, // amount of iterations to apply
hash: {name: "SHA-256"}, // can be "SHA-1", "SHA-256", "SHA-384" or "SHA-512"
},
importedKey,
{
// can be any supported AES algorithm ("AES-CTR", "AES-CBC", "AES-CMAC", "AES-GCM", "AES-CFB", "AES-KW", "ECDH", "DH" or "HMAC")
name: algo,
length: object.ks, // can be 128, 192 or 256
},
false, // the key may not be exported
["decrypt"] // we may only use it for decryption
)
// finally, decrypt message
var decrypted = await window.crypto.subtle.decrypt(
{
// can be any supported AES algorithm ("AES-CTR", "AES-CBC", "AES-CMAC", "AES-GCM", "AES-CFB", "AES-KW", "ECDH", "DH" or "HMAC")
name: algo,
iv: StrToArr(atob(object.iv)), // the initialization vector you used to encrypt
additionalData: StrToArr(atob(object.adata)), // the addtional data you used during encryption (if any)
tagLength: object.ts, // the length of the tag you used to encrypt (if any)
},
derivedKey,
StrToArr(atob(object.ct)) // cipher text to decrypt
)
return decompress(ArrToStr(decrypted));
} catch(err) {
return '';
}
};
@@ -673,33 +843,7 @@ jQuery.PrivateBin = (function($, sjcl, RawDeflate) {
*/
me.getSymmetricKey = function()
{
var crypto, key;
if (typeof module !== 'undefined' && module.exports) {
// node environment
key = require('crypto').randomBytes(32).toString('base64');
} else if (
typeof window !== 'undefined' &&
typeof Uint8Array !== 'undefined' &&
String.fromCodePoint &&
(
typeof window.crypto !== 'undefined' ||
typeof window.msCrypto !== 'undefined'
)
) {
// modern browser environment
var bytes = '',
byteArray = new Uint8Array(32),
crypto = window.crypto || window.msCrypto;
crypto.getRandomValues(byteArray);
for (var i = 0; i < 32; ++i) {
bytes += String.fromCharCode(byteArray[i]);
}
key = btoa(bytes);
} else {
// legacy browser or unsupported environment
throw 'No supported crypto API detected, you may read pastes and post comments, but can\'t create pastes.';
}
return key;
return btoa(getRandomBytes(32));
};
return me;

21
js/test/CryptTool.js
View File

@@ -10,10 +10,12 @@ describe('CryptTool', function () {
'string',
'string',
function (key, password, message) {
jsdom();
window.crypto = new WebCrypto();
return message === $.PrivateBin.CryptTool.decipher(
key,
password,
$.PrivateBin.CryptTool.cipher(key, password, message)
$.PrivateBin.CryptTool.cipher(key, password, message.trim())
);
}
),
@@ -25,15 +27,16 @@ describe('CryptTool', function () {
// SJCL based pastes still works
it(
'supports PrivateBin v1 ciphertext (SJCL & browser atob)',
function () {
async function () {
delete global.Base64;
// make btoa available
jsdom();
global.btoa = window.btoa;
window.crypto = new WebCrypto();
// Of course you can easily decipher the following texts, if you like.
// Bonus points for finding their sources and hidden meanings.
var paste1 = $.PrivateBin.CryptTool.decipher(
var paste1 = await $.PrivateBin.CryptTool.decipher(
'6t2qsmLyfXIokNCL+3/yl15rfTUBQvm5SOnFPvNE7Q8=',
// -- "That's amazing. I've got the same combination on my luggage."
Array.apply(0, Array(6)).map(function(_,b) { return b + 1; }).join(''),
@@ -65,7 +68,7 @@ describe('CryptTool', function () {
'C5fARPJ4F2BIWgzgzkNj+dVjusft2XnziamWdbS5u3kuRlVuz5LQj+R5' +
'imnqQAincdZTkTT1nYx+DatlOLllCYIHffpI="}'
),
paste2 = $.PrivateBin.CryptTool.decipher(
paste2 = await $.PrivateBin.CryptTool.decipher(
's9pmKZKOBN7EVvHpTA8jjLFH3Xlz/0l8lB4+ONPACrM=',
'', // no password
'{"iv":"WA42mdxIVXUwBqZu7JYNiw==","v":1,"iter":10000,"ks"' +
@@ -101,12 +104,14 @@ describe('CryptTool', function () {
it(
'supports ZeroBin ciphertext (SJCL & Base64 1.7)',
function () {
async function () {
global.Base64 = require('../base64-1.7').Base64;
jsdom();
window.crypto = new WebCrypto();
// Of course you can easily decipher the following texts, if you like.
// Bonus points for finding their sources and hidden meanings.
var paste1 = $.PrivateBin.CryptTool.decipher(
var paste1 = await $.PrivateBin.CryptTool.decipher(
'6t2qsmLyfXIokNCL+3/yl15rfTUBQvm5SOnFPvNE7Q8=',
// -- "That's amazing. I've got the same combination on my luggage."
Array.apply(0, Array(6)).map(function(_,b) { return b + 1; }).join(''),
@@ -130,7 +135,7 @@ describe('CryptTool', function () {
'V37AeiNoD2PcI6ZcHbRdPa+XRrRcJhSPPW7UQ0z4OvBfjdu/w390QxAx' +
'SxvZewoh49fKKB6hTsRnZb4tpHkjlww=="}'
),
paste2 = $.PrivateBin.CryptTool.decipher(
paste2 = await $.PrivateBin.CryptTool.decipher(
's9pmKZKOBN7EVvHpTA8jjLFH3Xlz/0l8lB4+ONPACrM=',
'', // no password
'{"iv":"Z7lAZQbkrqGMvruxoSm6Pw==","v":1,"iter":10000,"ks"' +
@@ -167,6 +172,8 @@ describe('CryptTool', function () {
'returns random, non-empty keys',
'integer',
function(counter) {
jsdom();
window.crypto = new WebCrypto();
var key = $.PrivateBin.CryptTool.getSymmetricKey(),
result = (key !== '' && keys.indexOf(key) === -1);
keys.push(key);

9
js/test/Helper.js
View File

@@ -213,15 +213,14 @@ describe('Helper', function () {
this.timeout(30000);
jsc.property(
'returns the requested cookie',
'nearray asciinestring',
'nearray asciistring',
jsc.nearray(jsc.nearray(common.jscAlnumString())),
jsc.nearray(jsc.nearray(common.jscAlnumString())),
function (labels, values) {
var selectedKey = '', selectedValue = '',
cookieArray = [];
labels.forEach(function(item, i) {
// deliberatly using a non-ascii key for replacing invalid characters
var key = item.replace(/[\s;,=]/g, Array(i+2).join('£')),
value = (values[i] || values[0]).replace(/[\s;,=]/g, '');
var key = item.join(''),
value = (values[i] || values[0]).join('');
cookieArray.push(key + '=' + value);
if (Math.random() < 1 / i || selectedKey === key)
{