feat: new chain

app/Services/Chain/EthAddress.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace App\Services\Chain;
+
+use kornrunner\Keccak;
+use RuntimeException;
+
+final class EthAddress
+{
+    public static function fromUncompressedPublicKey(string $publicKeyHex): string
+    {
+        $hex = strtolower($publicKeyHex);
+        if (str_starts_with($hex, '0x')) {
+            $hex = substr($hex, 2);
+        }
+        if (str_starts_with($hex, '04')) {
+            $hex = substr($hex, 2);
+        }
+        if (strlen($hex) !== 128) {
+            throw new RuntimeException('Expected uncompressed secp256k1 public key');
+        }
+
+        $hash = Keccak::hash(hex2bin($hex), 256);
+
+        return '0x'.substr($hash, -40);
+    }
+
+    public static function isValid(string $address): bool
+    {
+        return (bool) preg_match('/^0x[0-9a-fA-F]{40}$/', trim($address));
+    }
+
+    public static function normalize(string $address): string
+    {
+        return strtolower(trim($address));
+    }
+
+    /** 20-byte address without 0x, left-padded to 32 bytes for ABI. */
+    public static function toWord(string $address): string
+    {
+        $hex = self::normalize($address);
+        if (str_starts_with($hex, '0x')) {
+            $hex = substr($hex, 2);
+        }
+        if (strlen($hex) !== 40) {
+            throw new RuntimeException('Invalid ETH address');
+        }
+
+        return str_pad($hex, 64, '0', STR_PAD_LEFT);
+    }
+}