coruna-lab/app/Services/Chain/EthAddress.php

<?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);
    }
}