PHP學習筆記：區塊鏈技術與應用

// 计算MD5哈希值
$data = 'Hello, world!';
$hash = md5($data);
echo $hash; // 输出：5eb63bbbe01eeed093cb22bb8f5acdc3

// 计算SHA-256哈希值
$data2 = 'Hello, blockchain!';
$hash2 = hash('sha256', $data2);
echo $hash2; // 输出：bf8f2e9538fee49125cb8545eaec2c10d1c79040721847a706ca6481aa18951f

// 生成RSA密钥对
$res = openssl_pkey_new(array(
    'private_key_bits' => 2048,
    'private_key_type' => OPENSSL_KEYTYPE_RSA,
));
openssl_pkey_export($res, $privateKey);
$details = openssl_pkey_get_details($res);
$publicKey = $details['key'];
echo "Public Key: " . $publicKey;
echo "Private Key: " . $privateKey;

<?php
class Transaction {
    public $from;
    public $to;
    public $amount;
    public $timestamp;
    public $signature;
    
    public function __construct($from, $to, $amount) {
        $this->from = $from;
        $this->to = $to;
        $this->amount = $amount;
        $this->timestamp = time();
        $this->signature = '';
    }
    
    public function sign($privateKey) {
        $message = $this->from . $this->to . $this->amount . $this->timestamp;
        openssl_sign($message, $signature, $privateKey);
        $this->signature = base64_encode($signature);
    }
    
    public function verify($publicKey) {
        $message = $this->from . $this->to . $this->amount . $this->timestamp;
        $signature = base64_decode($this->signature);
        return openssl_verify($message, $signature, $publicKey);
    }
}

$privateKeyAlice = openssl_pkey_new();
$detailsAlice = openssl_pkey_get_details($privateKeyAlice);
$publicKeyAlice = $detailsAlice['key'];

$privateKeyBob = openssl_pkey_new();
$detailsBob = openssl_pkey_get_details($privateKeyBob);
$publicKeyBob = $detailsBob['key'];

$transaction = new Transaction($publicKeyAlice, $publicKeyBob, 10);
$transaction->sign($privateKeyAlice);
$isValid = $transaction->verify($publicKeyAlice);
if ($isValid) {
   echo "Transaction is valid.";
} else {
   echo "Transaction is not valid.";
}
?>