fix: use already instantiated username and use salt

Author: Laizerox

src/Wowemu/SRP/UserClient.php

@@ -39,16 +39,14 @@ public function setHostPublicEphemeralValue(string $value): void
     /**
      * Generate verifier using username, password and existing salt
      *
-     * @param  string  $I  User's identity (username)
      * @param  string  $p  User's password in plaintext
-     * @param  string  $s  User's salt
      *
      * @return string
      * @throws Exception
      */
-    public function generateVerifier(string $I, string $p, string $s): string
+    public function generateVerifier(string $p): string
     {
-        $privateKey = $this->computePrivateKey($s, $I, $p);
+        $privateKey = $this->computePrivateKey($p);
         $verifier = $this->computeVerifier($privateKey);
 
         return $verifier->toHex();
@@ -58,26 +56,22 @@ public function generateVerifier(string $I, string $p, string $s): string
      * Computes private key using salt and identity which is derived from username and password
      *
      * @param  string  $p  User's password in plaintext
-     * @param  string  $I  User's identity (username)
-     * @param  string  $s  User's salt
      *
      * @return BigInteger
      */
-    public function computePrivateKey(string $p, string $I = null, string $s = null): BigInteger
+    public function computePrivateKey(string $p): BigInteger
     {
-        $salt = $s ?? $this->salt;
-        if (empty($salt)) {
+        if (empty($this->salt)) {
             throw new RuntimeException('Received empty salt.');
         }
 
-        $username = $I ?? $this->username;
-        if (empty($username)) {
+        if (empty($this->username)) {
             throw new RuntimeException('Received empty username.');
         }
 
-        $salt = $this->reverseHex($salt);
+        $salt = $this->reverseHex($this->salt);
         $salt = hex2bin($salt);
-        $identity = hash('sha1', strtoupper($username.':'.$p), true);
+        $identity = hash('sha1', strtoupper($this->username.':'.$p), true);
 
         $sha = sha1($salt.$identity);
         $sha = $this->reverseHex($sha);

tests/UserClientTest.php

@@ -0,0 +1,73 @@
+<?php
+/*
+ * (c) Dmitri Petmanson <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Tests;
+
+use Exception;
+use Laizerox\Wowemu\SRP\UserClient;
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+
+class UserClientTest extends TestCase
+{
+    public function dataProvider(): array
+    {
+        return [
+            [
+                'admin',
+                'admin',
+                '12ee32e201835ebc6a00c7056f08e18651633ab9cec6cfd5a1bdda413747c74c',
+                '2b25415d6fd90435b9506f64c15e0670bef49a9905d62f21eb573dc4ff2bbaf0',
+            ],
+            [
+                'player',
+                'player',
+                '50b39832882cc3174f4b566d377775ecc33af5f21fa71bcac58290595101d4e9',
+                '59f9d68f247ff723c46677847e042923184307f652c297726da2868670c607bf',
+            ],
+        ];
+    }
+
+    /**
+     * @param $username
+     * @param $password
+     * @param $salt
+     * @param $expectedVerifier
+     *
+     * @dataProvider dataProvider
+     * @throws Exception
+     */
+    public function testGenerateVerifierAgainstExistingData($username, $password, $salt, $expectedVerifier): void
+    {
+        $client = new UserClient($username, $salt);
+
+        $this->assertEquals($expectedVerifier, $client->generateVerifier($password));
+    }
+
+    /**
+     * @throws Exception
+     */
+    public function testGenerateVerifierWithEmptyUsername(): void
+    {
+        $this->expectException(RuntimeException::class);
+
+        $client = new UserClient('');
+        $client->generateVerifier('');
+    }
+
+    /**
+     * @throws Exception
+     */
+    public function testGenerateVerifierWithEmptySalt(): void
+    {
+        $this->expectException(RuntimeException::class);
+
+        $client = new UserClient('admin');
+        $client->generateVerifier('admin');
+    }
+}