SEARCH-116-GCM This is using GCM mode

js/cryptoLib/crypto.js

@@ -0,0 +1,249 @@
+/**
+ * AES GCM Stream
+ * This module exports encrypt and decrypt stream constructors which can be
+ * used to protect data with authenticated encryption.
+ *
+ * Helper methods are also provided to do things like generate secure keys
+ * and salt.
+ */
+'use strict';
+
+let stream = require('stream');
+let Transform = stream.Transform;
+let util = require('util');
+let crypto = require('crypto');
+
+let PBKDF2_PASS_LENGTH = 256;
+let PBKDF2_SALT_LENGTH = 32;
+let PBKDF2_ITERATIONS = 5000;
+let PBKDF2_DIGEST = 'sha256';
+let KEY_LENGTH = 32; // bytes
+let GCM_NONCE_LENGTH = 12; //bytes
+let GCM_MAC_LENGTH = 16; //bytes
+
+let keyEncoding = 'base64';
+
+/**
+ * Private helper method to validate a key passed into the Encrypt and Decrypt streams.
+ * Strings are converted it into a buffer, buffers are returned as they are.
+ * @param key
+ * @throws Missing, Encoding, or Length errors
+ * @returns Buffer
+ */
+let validateAndConvertKey = function(key) {
+    if (key && key instanceof Buffer && key.length === KEY_LENGTH) {
+        return key;
+    } else if (key && typeof key === 'string') {
+        // Because we don't have a reliable way to test string encoding, we assume that a string type
+        // key was created by the createEncodedKey method and that it is using the keyEncoding which
+        // has been set on the module, whether that's the default or something explicitly set by the
+        // user via the setKeyEncoding method.
+        let bufKey = new Buffer(key, keyEncoding);
+        if (bufKey.length !== KEY_LENGTH) {
+            let encodingErrorMessage = 'Provided key string is either of an unknown encoding (expected: ' +
+                keyEncoding + ') or the wrong length.';
+            throw new Error(encodingErrorMessage);
+        }
+        return bufKey;
+    } else {
+        let message = 'The key options property is required! Expected ' +
+            keyEncoding + ' encoded string or a buffer.';
+        throw new Error(message);
+    }
+};
+
+exports.encrypt = EncryptionStream;
+exports.decrypt = DecryptionStream;
+
+/**
+ * getEncoding
+ * Helper which returns the current encoding being used for keys
+ * @returns {string}
+ */
+exports.getKeyEncoding = function() {
+    return keyEncoding;
+};
+
+/**
+ * setEncoding
+ * Helper to set the encoding being used for keys
+ * @param enc
+ */
+exports.setKeyEncoding = function(enc) {
+    keyEncoding = Buffer.isEncoding(enc) ? enc : keyEncoding;
+};
+
+/**
+ * createSalt
+ * Helper method that returns a salt
+ * @returns string
+ * @throws error
+ */
+exports.createSalt = function(length) {
+    try {
+        return crypto.randomBytes(length);
+    } catch (ex) {
+        console.error('Problem reading random data and generating salt!');
+        throw ex;
+    }
+};
+
+/**
+ * createKeyBuffer
+ * Method which returns a buffer representing a secure key generated with PBKDF2
+ * @returns Buffer
+ */
+exports.createKeyBuffer = function() {
+    try {
+        let passphrase = crypto.randomBytes(PBKDF2_PASS_LENGTH);
+        let salt = this.createSalt(PBKDF2_SALT_LENGTH);
+        return crypto.pbkdf2Sync(passphrase, salt, PBKDF2_ITERATIONS, KEY_LENGTH, PBKDF2_DIGEST);
+    } catch (ex) {
+        console.error('Problem reading random data and generating a key!');
+        throw ex;
+    }
+};
+
+/**
+ * createEncodedKey
+ * Helper method that returns an encoded key
+ * @returns string
+ * @throws error
+ */
+exports.createEncodedKey = function() {
+    return exports.createKeyBuffer().toString(keyEncoding);
+};
+
+/**
+ * EncryptionStream
+ * A constructor which returns an encryption stream
+ * The stream first outputs a 12 byte nonce then encrypted cipher text.
+ * When the stream is flushed it outputs a 16 byte MAC.
+ * @param options Object Object.key is the only required param
+ * @returns {EncryptionStream}
+ * @constructor
+ */
+function EncryptionStream(options) {
+    if (!(this instanceof EncryptionStream)) {
+        return new EncryptionStream(options);
+    }
+
+    let nonce = options.nonce || exports.createSalt(12);
+
+    this._key = validateAndConvertKey(options.key);
+    this._cipher = crypto.createCipheriv('aes-256-gcm', this._key, nonce);
+
+    Transform.call(this, options);
+    this.push(nonce);
+}
+util.inherits(EncryptionStream, Transform);
+
+EncryptionStream.prototype._transform = function(chunk, enc, cb) {
+    this.push(this._cipher.update(chunk));
+    cb();
+};
+
+EncryptionStream.prototype._flush = function(cb) {
+    // final must be called on the cipher before generating a MAC
+    this._cipher.final(); // this will never output data
+    this.push(this._cipher.getAuthTag()); // 16 bytes
+
+    cb();
+};
+
+
+/**
+ * DecryptionStream
+ * A constructor which returns a decryption stream
+ * The stream assumes the first 12 bytes of data are the nonce and the final
+ * 16 bytes received is the MAC.
+ * @param options Object Object.key is the only required param
+ * @returns {DecryptionStream}
+ * @constructor
+ */
+function DecryptionStream(options) {
+    if (!(this instanceof DecryptionStream)) {
+        return new DecryptionStream(options);
+    }
+
+    this._started = false;
+    this._nonce = new Buffer(GCM_NONCE_LENGTH);
+    this._nonceBytesRead = 0;
+    this._cipherTextChunks = [];
+    this._key = validateAndConvertKey(options.key);
+
+    Transform.call(this, options);
+}
+util.inherits(DecryptionStream, Transform);
+
+DecryptionStream.prototype._transform = function(chunk, enc, cb) {
+    let chunkLength = chunk.length;
+    let chunkOffset = 0;
+    if (!this._started) {
+        if (this._nonceBytesRead < GCM_NONCE_LENGTH) {
+            let nonceRemaining = GCM_NONCE_LENGTH - this._nonceBytesRead;
+            chunkOffset = chunkLength <= nonceRemaining ? chunkLength : nonceRemaining;
+            chunk.copy(this._nonce, this._nonceBytesRead, 0, chunkOffset);
+            chunk = chunk.slice(chunkOffset);
+            chunkLength = chunk.length;
+            this._nonceBytesRead += chunkOffset;
+        }
+
+
+        if (this._nonceBytesRead === GCM_NONCE_LENGTH) {
+            this._decipher = crypto.createDecipheriv('aes-256-gcm', this._key, this._nonce);
+            this._started = true;
+        }
+    }
+
+    // We can't use an else because we have no idea how long our chunks will be
+    // all we know is that once we've got a nonce we can start storing cipher text
+    if (this._started) {
+        this._cipherTextChunks.push(chunk);
+    }
+
+    cb();
+};
+
+DecryptionStream.prototype._flush = function(cb) {
+    let mac = pullOutMac(this._cipherTextChunks);
+    if (!mac) {
+        return this.emit('error', new Error('Decryption failed: bad cipher text.'));
+    }
+    this._decipher.setAuthTag(mac);
+    let decrypted = this._cipherTextChunks.map(function(item) {
+        return this._decipher.update(item);
+    }, this);
+    try {
+        this._decipher.final();
+    } catch (e) {
+        return cb(e);
+    }
+    decrypted.forEach(function(item) {
+        this.push(item);
+    }, this);
+    cb();
+};
+
+function pullOutMac(array) {
+    let macBits = [];
+    let macByteCount = 0;
+    let current, macStartIndex;
+    while (macByteCount !== GCM_MAC_LENGTH && array.length) {
+        current = array.pop();
+        if (macByteCount + current.length <= GCM_MAC_LENGTH) {
+            macBits.push(current);
+            macByteCount += current.length;
+        } else {
+            macStartIndex = (macByteCount + current.length) - GCM_MAC_LENGTH;
+            macBits.push(current.slice(macStartIndex));
+            array.push(current.slice(0, macStartIndex));
+            macByteCount += (current.length - macStartIndex);
+        }
+    }
+    if (macByteCount !== GCM_MAC_LENGTH) {
+        return;
+    }
+    macBits.reverse();
+    return Buffer.concat(macBits, GCM_MAC_LENGTH);
+}

js/cryptoLib/index.js

@@ -3,26 +3,31 @@ const electron = require('electron');
 const app = electron.app;
 const path = require('path');
 const fs = require('fs');
-const crypto = require('crypto');
 const archiver = require('archiver');
 const zipArchive = archiver('zip');
 const extract = require('extract-zip');
 const isDevEnv = require('../utils/misc.js').isDevEnv;
+const crypto = require('./crypto');
 
 const userData = path.join(app.getPath('userData'));
-const INDEX_DATA_FOLDER = isDevEnv ? './msgsjson' : path.join(userData, 'data');
-const MODE = 'aes-256-ctr';
+const INDEX_DATA_FOLDER = isDevEnv ? './data' : path.join(userData, 'data');
+const TEMPORARY_PATH = isDevEnv ? path.join(__dirname, '..', '..') : userData;
 
 class Crypto {
 
     constructor() {
         this.indexDataFolder = INDEX_DATA_FOLDER;
-        this.key = '53796d70686f6e792074657374206b657920666f7220656e6372797074696f6e20';
-        this.dump = path.join(__dirname, '..', '..');
+        this.dump = TEMPORARY_PATH;
+        this.key = "XrwVgWR4czB1a9scwvgRUNbXiN3W0oWq7oUBenyq7bo="; // temporary only
         this.encryptedIndex = 'encryptedIndex.enc';
         this.zipErrored = false;
     }
 
+    /**
+     * Creates a zip of the data folder and encrypting
+     * removing the data folder and the dump files
+     * @returns {Promise}
+     */
     encryption() {
         return new Promise((resolve, reject) => {
 
@@ -32,9 +37,12 @@ class Crypto {
 
                 const input = fs.createReadStream(`${this.dump}/content.zip`);
                 const outputEncryption = fs.createWriteStream(this.encryptedIndex);
-                const cipher = crypto.createCipher(MODE, this.key);
+                let config = {
+                    key: this.key
+                };
+                const encrypt = crypto.encrypt(config);
 
-                input.pipe(cipher).pipe(outputEncryption).on('finish', (err, res) => {
+                input.pipe(encrypt).pipe(outputEncryption).on('finish', (err, res) => {
                     if (err) {
                         reject(new Error(err));
                     }
@@ -64,52 +72,66 @@ class Crypto {
         });
     }
 
+    /**
+     * Decrypting the .enc file and unzipping
+     * removing the .enc file and the dump files
+     * @returns {Promise}
+     */
     decryption() {
         return new Promise((resolve, reject) => {
             const input = fs.createReadStream(this.encryptedIndex);
             const output = fs.createWriteStream(`${this.dump}/decrypted.zip`);
-            const deCipher = crypto.createDecipher(MODE, this.key);
+            let config = {
+                key: this.key
+            };
+            const decrypt = crypto.decrypt(config);
 
-            input.pipe(deCipher).pipe(output).on('finish', () => {
+            input.pipe(decrypt).pipe(output).on('finish', () => {
                 let readStream = fs.createReadStream(`${this.dump}/decrypted.zip`);
                 readStream
                     .on('data', (data) => {
                         if (!data) {
                             reject(new Error("error reading zip"));
                         }
-                        unzip();
+                        zip();
                     })
                     .on('error', (error) => {
                         reject(new Error(error.message));
                     });
             });
 
-            let unzip = () => {
-                let temp = path.join(__dirname, '..', '..');
-                extract(`${this.dump}/decrypted.zip`, {dir: temp}, (err) => {
+            let zip = () => {
+                extract(`${this.dump}/decrypted.zip`, {dir: TEMPORARY_PATH}, (err) => {
                     if (err) {
                         reject(new Error(err));
                     }
                     fs.unlink(`${this.dump}/decrypted.zip`, () => {
-                        resolve('success')
+                        fs.unlink(this.encryptedIndex, () => {
+                            resolve('success');
+                        })
                     });
                 })
-            };
+            }
         });
     }
 
-    static deleteFolderRecursive(pt) {
+    /**
+     * Removing all the folders and files inside the data folder
+     * @param {String} location
+     * @returns {Promise}
+     */
+    static deleteFolderRecursive(location) {
         return new Promise((resolve, reject) => {
-            if (fs.existsSync(pt)) {
-                fs.readdirSync(pt).forEach((file) => {
-                    let curPath = pt + "/" + file;
+            if (fs.existsSync(location)) {
+                fs.readdirSync(location).forEach((file) => {
+                    let curPath = location + "/" + file;
                     if (fs.lstatSync(curPath).isDirectory()) {
                         Crypto.deleteFolderRecursive(curPath);
                     } else {
                         fs.unlinkSync(curPath);
                     }
                 });
-                resolve(fs.rmdirSync(pt));
+                resolve(fs.rmdirSync(location));
             } else {
                 reject('no file');
             }