PROSAGA码农传奇-以太坊-如何在PHP中验证以太坊地址

这是一个针对EIP 55规范的以太坊地址验证的PHP实现。有关其工作方式的详细信息，请仔细阅读注释。

```
<?php

use kornrunner\Keccak; // composer require greensea/keccak

class EthereumValidator
{
    public function isAddress(string $address): bool
    {
        // See: https://github.com/ethereum/web3.js/blob/7935e5f/lib/utils/utils.js#L415
        if ($this->matchesPattern($address)) {
            return $this->isAllSameCaps($address) ?: $this->isValidChecksum($address);
        }

return false;
    }

protected function matchesPattern(string $address): int
    {
        return preg_match('/^(0x)?[0-9a-f]{40}$/i', $address);
    }

protected function isAllSameCaps(string $address): bool
    {
        return preg_match('/^(0x)?[0-9a-f]{40}$/', $address) || preg_match('/^(0x)?[0-9A-F]{40}$/', $address);
    }

protected function isValidChecksum($address)
    {
        $address = str_replace('0x', '', $address);
        $hash = Keccak::hash(strtolower($address), 256);

// See: https://github.com/web3j/web3j/pull/134/files#diff-db8702981afff54d3de6a913f13b7be4R42
        for ($i = 0; $i < 40; $i++ ) {
            if (ctype_alpha($address{$i})) {
                // Each uppercase letter should correlate with a first bit of 1 in the hash char with the same index,
                // and each lowercase letter with a 0 bit.
                $charInt = intval($hash{$i}, 16);

if ((ctype_upper($address{$i}) && $charInt <= 7) || (ctype_lower($address{$i}) && $charInt > 7)) {
                    return false;
                }
            }
        }

return true;
    }
}
```

依存关系
为了验证校验和地址，我们需要适当的keccak-256实现，而内置hash()函数不支持该实现。您需要将greensea / keccak作曲家软件包作为依赖项。

@WebSpanner指出了SHA3哈希问题。