add support for dynamic decryption algorithms + version bump

Author: doersf

lib/block_io.js

@@ -25,7 +25,6 @@ function BlockIo (config, pin, version, options) {
 
     if (pin) {
       this.pin = pin;
-      this.aesKey = helper.pinToKey(this.pin);
     }
 
     if (options && typeof(options) == 'object') this._cloneOptions(options);
@@ -39,7 +38,6 @@ function BlockIo (config, pin, version, options) {
 
     if (config.pin) {
       this.pin = config.pin;
-      this.aesKey = helper.pinToKey(this.pin);
     }
 
     if (config.options) this._cloneOptions(config.options);
@@ -174,24 +172,12 @@ BlockIo.prototype.create_and_sign_transaction = function (args, cb) {
 
 	if (Object.prototype.hasOwnProperty.call(data.data, 'user_key')) {
 	    if (this.keys[data.data.user_key.public_key] === undefined) {
-		if (this.aesKey === undefined && args.pin === undefined) {
+		if (this.pin === undefined && args.pin === undefined) {
 		    throw("Must either instantiate object with a PIN, or provide the PIN for create_and_sign_transaction to decrypt the private key");
-		} else if (this.aesKey !== undefined || args.pin !== undefined) {
+		} else if (this.pin !== undefined || args.pin !== undefined) {
 		    // the user provided the PIN here, so let's use it
 
-		    let tempAesKey = undefined;
-		    
-		    if (this.aesKey === undefined && args.pin !== undefined) {
-			tempAesKey = helper.pinToKey(args.pin);
-		    } else {
-			tempAesKey = this.aesKey;
-		    }
-
-		    // we have the AES Key now
-		    // If we get here, Block.io's asking us to provide client-side signatures
-		    // since the user_key is provided, we want to decrypt the private key from it
-		    const encrypted_passphrase = data.data.user_key.encrypted_passphrase;
-		    let privkey = helper.extractKey(encrypted_passphrase, tempAesKey);
+		    let privkey = helper.dynamicExtractKey(data.data.user_key, this.pin || args.pin);
 
 		    if (!(privkey instanceof ECKey))
 			return r(new Error(ERR_PK_EXTR));

lib/helper.js

@@ -129,6 +129,26 @@ Helper.pinToKey = function (pin, salt, iterations, hash_function, phase1_key_len
 	return buf.toString('base64');
 };
 
+Helper.dynamicExtractKey = function (user_key, pin) {
+    // uses the appropriate algorithm to decrypt user's private key
+
+    // legacy
+    let algorithm = JSON.parse("{\"pbkdf2_salt\":\"\",\"pbkdf2_iterations\":2048,\"pbkdf2_hash_function\":\"SHA256\",\"pbkdf2_phase1_key_length\":16,\"pbkdf2_phase2_key_length\":32,\"aes_iv\":null,\"ae\
+s_cipher\":\"AES-256-ECB\",\"aes_auth_tag\":null,\"aes_auth_data\":null}");
+
+    // we got the algorithm, so use that instead
+    if (user_key.algorithm) algorithm = user_key.algorithm;
+    
+    const aes_key = this.pinToKey(pin, algorithm.pbkdf2_salt, algorithm.pbkdf2_iterations, algorithm.pbkdf2_hash_function, algorithm.pbkdf2_phase1_key_length,
+                                  algorithm.pbkdf2_phase2_key_length);
+    const decrypted = this.decrypt(user_key.encrypted_passphrase, aes_key,
+                                   algorithm.aes_iv, algorithm.aes_cipher,
+                                   algorithm.aes_auth_tag,
+                                   algorithm.aes_auth_data);
+    
+    return ECKey.fromPassphrase(decrypted);
+};
+
 Helper.extractKey = function (encrypted_data, b64_enc_key) {
 	const decrypted = this.decrypt(encrypted_data, b64_enc_key);
 	return ECKey.fromPassphrase(decrypted);

package.json

@@ -9,7 +9,7 @@
     "dogecoin",
     "wallet"
   ],
-  "version": "4.0.0",
+  "version": "4.0.1",
   "preferGlobal": false,
   "homepage": "https://github.com/BlockIo/block_io-nodejs",
   "author": "Patrick Lodder <patrick.lodder@gmail.com> (https://github.com/patricklodder)",

test/unit/cryptohelper.js

@@ -95,6 +95,39 @@ test('Encrypt using AES-256-GCM', t => {
 
 });
 
+test("DynamicExtractKey using AES-256-ECB", t => {
+    t.plan(2)
+
+    let user_key = JSON.parse('{"encrypted_passphrase":"3wIJtPoC8KO6S7x6LtrN0g==","public_key":"02f87f787bffb30396984cb6b3a9d6830f32d5b656b3e39b0abe4f3b3c35d99323","algorithm":{"pbkdf2_salt":"","pbkdf2_iterations":2048,"pbkdf2_hash_function":"SHA256","pbkdf2_phase1_key_length":16,"pbkdf2_phase2_key_length":32,"aes_iv":null,"aes_cipher":"AES-256-ECB","aes_auth_tag":null,"aes_auth_data":null}}');
+    
+    t.doesNotThrow(() => {
+	let key = CryptoHelper.dynamicExtractKey(user_key, "deadbeef");
+	t.equal(key.pub.toString('hex'), user_key.public_key, 'must return correct public key');
+    }, undefined, 'does not throw any Errors');
+});
+
+test("DynamicExtractKey using AES-256-CBC", t => {
+    t.plan(2)
+
+    let user_key = JSON.parse('{"encrypted_passphrase":"LExu1rUAtIBOekslc328Lw==","public_key":"02f87f787bffb30396984cb6b3a9d6830f32d5b656b3e39b0abe4f3b3c35d99323","algorithm":{"pbkdf2_salt":"922445847c173e90667a19d90729e1fb","pbkdf2_iterations":500000,"pbkdf2_hash_function":"SHA256","pbkdf2_phase1_key_length":16,"pbkdf2_phase2_key_length":32,"aes_iv":"11bc22166c8cf8560e5fa7e5c622bb0f","aes_cipher":"AES-256-CBC","aes_auth_tag":null,"aes_auth_data":null}}');
+    
+    t.doesNotThrow(() => {
+	let key = CryptoHelper.dynamicExtractKey(user_key, "deadbeef");
+	t.equal(key.pub.toString('hex'), user_key.public_key, 'must return correct public key');
+    }, undefined, 'does not throw any Errors');
+});
+
+test("DynamicExtractKey using AES-256-GCM", t => {
+    t.plan(2)
+
+    let user_key = JSON.parse('{"encrypted_passphrase":"ELV56Z57KoA=","public_key":"02f87f787bffb30396984cb6b3a9d6830f32d5b656b3e39b0abe4f3b3c35d99323","algorithm":{"pbkdf2_salt":"922445847c173e90667a19d90729e1fb","pbkdf2_iterations":500000,"pbkdf2_hash_function":"SHA256","pbkdf2_phase1_key_length":16,"pbkdf2_phase2_key_length":32,"aes_iv":"a57414b88b67f977829cbdca","aes_cipher":"AES-256-GCM","aes_auth_tag":"adeb7dfe53027bdda5824dc524d5e55a","aes_auth_data":""}}');
+    
+    t.doesNotThrow(() => {
+	let key = CryptoHelper.dynamicExtractKey(user_key, "deadbeef");
+	t.equal(key.pub.toString('hex'), user_key.public_key, 'must return correct public key');
+    }, undefined, 'does not throw any Errors');
+});
+
 test('Satoshis from value string', t => {
   t.plan(4);