本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# 使用 PHP 建立已簽署 Cookie
<a name="signed-cookies-PHP"></a>

下列程式碼範例類似於 [使用 PHP 建立 URL 簽章](CreateURL_PHP.md) 中建立影片連結的範例。不過，此範例不會在程式碼中簽署 URL，而是使用 `create_signed_cookies()` 函數簽署 Cookie。用戶端播放器使用 Cookie 對 CloudFront 分佈的每個請求進行身分驗證。

此方法有助於串流內容，例如 HTTP Live Streaming (HLS) 或透過 HTTP 的動態自適應串流 (DASH)，其中用戶端需要提出多個請求來擷取資訊清單、區段和相關播放資產。透過使用簽署的 Cookie，用戶端可以驗證每個請求，而不需要為每個區段產生新的已簽署 URL。

**注意**  
建立 URL 簽章只是私有內容提供服務的程序的一部分，以使用已簽署 Cookie。如需詳細資訊，請參閱[使用已簽署 Cookie](private-content-signed-cookies.md)。



**Topics**
+ [建立 RSA SHA-1 或 SHA-256 簽章](#create-rsa-sha-1signature-cookies)
+ [建立已簽署 Cookie](#create-the-signed-cookie)
+ [完整程式碼](#full-code-signed-cookies)

下列各節將程式碼範例細分為個別部分。您可以在下面找到完整的[程式碼範例](#full-code-signed-cookies)。

## 建立 RSA SHA-1 或 SHA-256 簽章
<a name="create-rsa-sha-1signature-cookies"></a>

此程式碼會執行下列操作：

1. 函數會使用 SHA-1 雜`rsa_sha1_sign`湊並簽署政策陳述式。若要改用 SHA-256，請使用如下所示的 rsa\$1sha256\$1sign 函數。所需的引數為政策陳述式，以及與您分佈之信任金鑰群組中公有金鑰對應的私有金鑰。

1. 接著，該 `url_safe_base64_encode` 函數會建立已簽章的 URL 安全版本。

   ```
   function rsa_sha1_sign($policy, $private_key_filename) {
       $signature = "";
       $fp = fopen($private_key_filename, "r");
       $priv_key = fread($fp, 8192);
       fclose($fp);
       $pkeyid = openssl_get_privatekey($priv_key);
       openssl_sign($policy, $signature, $pkeyid);
       openssl_free_key($pkeyid);
       return $signature;
   }
   
   function url_safe_base64_encode($value) {
       $encoded = base64_encode($value);
       return str_replace(
           array('+', '=', '/'),
           array('-', '_', '~'),
           $encoded);
   }
   ```

   下列函數使用 SHA-256 而非 SHA-1：

   ```
   function rsa_sha256_sign($policy, $private_key_filename) {
       $signature = "";
       $fp = fopen($private_key_filename, "r");
       $priv_key = fread($fp, 8192);
       fclose($fp);
       $pkeyid = openssl_get_privatekey($priv_key);
       openssl_sign($policy, $signature, $pkeyid, OPENSSL_ALGO_SHA256);
       openssl_free_key($pkeyid);
       return $signature;
   }
   ```

   `rsa_sha256_sign` 函數與 相同`rsa_sha1_sign`，但會傳遞`OPENSSL_ALGO_SHA256`給 `openssl_sign`。當您使用 SHA-256 時，請包含值為 的 `CloudFront-Hash-Algorithm` Cookie`SHA256`。

## 建立已簽署 Cookie
<a name="create-the-signed-cookie"></a>

下列程式碼會使用下列 Cookie 屬性來建構 建立簽章的 Cookie：`CloudFront-Expires`、 `CloudFront-Signature``CloudFront-Key-Pair-Id`和 `CloudFront-Hash-Algorithm`。程式碼使用自訂政策。

```
function create_signed_cookies($resource, $private_key_filename, $key_pair_id, $expires, $client_ip = null, $hash_algorithm = 'SHA1') {
    $policy = array(
        'Statement' => array(
            array(
                'Resource' => $resource,
                'Condition' => array(
                    'DateLessThan' => array('AWS:EpochTime' => $expires)
                )
            )
        )
    );

    if ($client_ip) {
        $policy['Statement'][0]['Condition']['IpAddress'] = array('AWS:SourceIp' => $client_ip . '/32');
    }

    $policy = json_encode($policy);
    $encoded_policy = url_safe_base64_encode($policy);
    if ($hash_algorithm === 'SHA256') {
        $signature = rsa_sha256_sign($policy, $private_key_filename);
    } else {
        $signature = rsa_sha1_sign($policy, $private_key_filename);
    }
    $encoded_signature = url_safe_base64_encode($signature);

    $cookies = array(
        'CloudFront-Policy' => $encoded_policy,
        'CloudFront-Signature' => $encoded_signature,
        'CloudFront-Key-Pair-Id' => $key_pair_id
    );

    if ($hash_algorithm === 'SHA256') {
        $cookies['CloudFront-Hash-Algorithm'] = 'SHA256';
    }

    return $cookies;
}
```

如需詳細資訊，請參閱[使用自訂政策設定已簽署 Cookie](private-content-setting-signed-cookie-custom-policy.md)。

## 完整程式碼
<a name="full-code-signed-cookies"></a>

下面的範例程式碼提供了使用 PHP 建立 CloudFront 已簽署 Cookie 的完整示範。您可以從 [demo-php.zip](samples/demo-php.zip) 檔案下載完整範例。

您可以在下列範例中修改 `$policy Condition` 元素，以允許 IPv4 與 IPv6 位址範圍。如需範例，請參閱《*Amazon Simple Storage Service 使用者指南*》中的[在 IAM 政策中使用 IPv6 位址](https://docs.aws.amazon.com/AmazonS3/latest/userguide/ipv6-access.html#ipv6-access-iam)。

```
<?php

function rsa_sha1_sign($policy, $private_key_filename) {
    $signature = "";
    $fp = fopen($private_key_filename, "r");
    $priv_key = fread($fp, 8192);
    fclose($fp);
    $pkeyid = openssl_get_privatekey($priv_key);
    openssl_sign($policy, $signature, $pkeyid);
    openssl_free_key($pkeyid);
    return $signature;
}

function url_safe_base64_encode($value) {
    $encoded = base64_encode($value);
    return str_replace(
        array('+', '=', '/'),
        array('-', '_', '~'),
        $encoded);
}

function rsa_sha256_sign($policy, $private_key_filename) {
    $signature = "";
    $fp = fopen($private_key_filename, "r");
    $priv_key = fread($fp, 8192);
    fclose($fp);
    $pkeyid = openssl_get_privatekey($priv_key);
    openssl_sign($policy, $signature, $pkeyid, OPENSSL_ALGO_SHA256);
    openssl_free_key($pkeyid);
    return $signature;
}

function create_signed_cookies($resource, $private_key_filename, $key_pair_id, $expires, $client_ip = null, $hash_algorithm = 'SHA1') {
    $policy = array(
        'Statement' => array(
            array(
                'Resource' => $resource,
                'Condition' => array(
                    'DateLessThan' => array('AWS:EpochTime' => $expires)
                )
            )
        )
    );

    if ($client_ip) {
        $policy['Statement'][0]['Condition']['IpAddress'] = array('AWS:SourceIp' => $client_ip . '/32');
    }

    $policy = json_encode($policy);
    $encoded_policy = url_safe_base64_encode($policy);
    if ($hash_algorithm === 'SHA256') {
        $signature = rsa_sha256_sign($policy, $private_key_filename);
    } else {
        $signature = rsa_sha1_sign($policy, $private_key_filename);
    }
    $encoded_signature = url_safe_base64_encode($signature);

    $cookies = array(
        'CloudFront-Policy' => $encoded_policy,
        'CloudFront-Signature' => $encoded_signature,
        'CloudFront-Key-Pair-Id' => $key_pair_id
    );

    if ($hash_algorithm === 'SHA256') {
        $cookies['CloudFront-Hash-Algorithm'] = 'SHA256';
    }

    return $cookies;
}



$private_key_filename = '/home/test/secure/example-priv-key.pem';
$key_pair_id = 'K2JCJMDEHXQW5F';
$base_url = 'https://d1234.cloudfront.net';

$expires = time() + 3600; // 1 hour from now

// Get the viewer real IP from the x-forward-for header as $_SERVER['REMOTE_ADDR'] will return viewer facing IP. An alternative option is to use CloudFront-Viewer-Address header. Note that this header is a trusted CloudFront immutable header. Example format: IP:PORT ("CloudFront-Viewer-Address": "1.2.3.4:12345")
$client_ip = $_SERVER['HTTP_X_FORWARDED_FOR'];


// For HLS manifest and segments (using wildcard)
$hls_resource = $base_url . '/sign/*';
$signed_cookies = create_signed_cookies($hls_resource, $private_key_filename, $key_pair_id, $expires, $client_ip, 'SHA256');

// Set the cookies
$cookie_domain = parse_url($base_url, PHP_URL_HOST);
foreach ($signed_cookies as $name => $value) {
    setcookie($name, $value, $expires, '/', $cookie_domain, true, true);
}

?>

<!DOCTYPE html>
<html>
<head>
    <title>CloudFront Signed HLS Stream with Cookies</title>
</head>
<body>
    <h1>Amazon CloudFront Signed HLS Stream with Cookies</h1>
    <h2>Expires at <?php echo gmdate('Y-m-d H:i:s T', $expires); ?> only viewable by IP <?php echo $client_ip; ?></h2>
    
    <div id='hls-video'>
        <video id="video" width="640" height="360" controls></video>
    </div>

    <script src="https://cdn.jsdelivr.net/npm/hls.js@latest"></script>
    <script>
        var video = document.getElementById('video');
        var manifestUrl = '<?php echo $base_url; ?>/sign/manifest.m3u8';
        
        if (Hls.isSupported()) {
            var hls = new Hls();
            hls.loadSource(manifestUrl);
            hls.attachMedia(video);
        }
        else if (video.canPlayType('application/vnd.apple.mpegurl')) {
            video.src = manifestUrl;
        }
    </script>
</body>
</html>
```

您可以使用已簽署 URL，而不是使用已簽署 Cookie。如需詳細資訊，請參閱[使用 PHP 建立 URL 簽章](CreateURL_PHP.md)。