From 6d9c35917dd112c41ae8156b05fa6603b7689f14 Mon Sep 17 00:00:00 2001
From: sc0Vu <alk03073135@gmail.com>
Date: Fri, 5 Jul 2024 15:53:48 +0800
Subject: [PATCH] Return true only when the address is lowercase or in checksum
 format

---
 src/Utils.php           | 9 +++++----
 test/unit/UtilsTest.php | 9 ++++++---
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/Utils.php b/src/Utils.php
index 7a5caa1..f0fdd84 100644
--- a/src/Utils.php
+++ b/src/Utils.php
@@ -175,16 +175,14 @@ public static function isNegative($value)
      * isAddress
      * 
      * @param string $value
-     * @return bool
+     * @return bool true if the address is lowercase or in checksum format otherwise false
      */
     public static function isAddress($value)
     {
         if (!is_string($value)) {
             throw new InvalidArgumentException('The value to isAddress function must be string.');
         }
-        if (preg_match('/^(0x|0X)?[a-f0-9A-F]{40}$/', $value) !== 1) {
-            return false;
-        } elseif (preg_match('/^(0x|0X)?[a-f0-9]{40}$/', $value) === 1 || preg_match('/^(0x|0X)?[A-F0-9]{40}$/', $value) === 1) {
+        if (preg_match('/^(0x)?[a-f0-9]{40}$/', $value) === 1) {
             return true;
         }
         return self::isAddressChecksum($value);
@@ -202,6 +200,9 @@ public static function isAddressChecksum($value)
             throw new InvalidArgumentException('The value to isAddressChecksum function must be string.');
         }
         $value = self::stripZero($value);
+        if (mb_strlen($value) !== 40) {
+            return false;
+        }
         $hash = self::stripZero(self::sha3(mb_strtolower($value)));
 
         for ($i = 0; $i < 40; $i++) {
diff --git a/test/unit/UtilsTest.php b/test/unit/UtilsTest.php
index da2e4e7..76244ed 100644
--- a/test/unit/UtilsTest.php
+++ b/test/unit/UtilsTest.php
@@ -232,17 +232,20 @@ public function testIsAddress()
         $this->assertEquals($isAddress, true);
 
         $isAddress = Utils::isAddress('0Xca35b7d915458ef540ade6068dfe2f44e8fa733c');
-        $this->assertEquals($isAddress, true);
+        $this->assertEquals($isAddress, false);
 
         $isAddress = Utils::isAddress('0XCA35B7D915458EF540ADE6068DFE2F44E8FA733C');
-        $this->assertEquals($isAddress, true);
+        $this->assertEquals($isAddress, false);
 
         $isAddress = Utils::isAddress('0xCA35B7D915458EF540ADE6068DFE2F44E8FA733C');
-        $this->assertEquals($isAddress, true);
+        $this->assertEquals($isAddress, false);
 
         $isAddress = Utils::isAddress('0xCA35B7D915458EF540ADE6068DFE2F44E8FA73cc');
         $this->assertEquals($isAddress, false);
 
+        $isAddress = Utils::isAddress('0xCA35b7d915458Ef540ADE6068DfE2F44E8fA73cC');
+        $this->assertEquals($isAddress, true);
+
         $this->expectException(InvalidArgumentException::class);
         $isAddress = Utils::isAddress(new stdClass);
     }