如何在 AWS Cloudfront 中组合流名称？

Question

Amazon Cloudfront SDK 和示例代码 - 如何组合流名称？所有其他功能都已详细说明，但我看不到 create_stream_name().

的任何定义或示例

下面是此处文档中描述的示例的完整代码：https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/CreateURL_PHP.html

如你所见，函数create_stream_name()并没有出现在任何地方，而是在第12行被调用，这将导致"call to undefined function"错误。我应该如何定义 create_stream_name()?

function get_canned_policy_stream_name($video_path, $private_key_filename, $key_pair_id, $expires) {
        // this policy is well known by CloudFront, but you still need to sign it, 
        // since it contains your parameters
        $canned_policy = '{"Statement":[{"Resource":"' . $video_path . '","Condition":{"DateLessThan":{"AWS:EpochTime":'. $expires . '}}}]}';

        // sign the canned policy
        $signature = $this->rsa_sha1_sign($canned_policy, $private_key_filename);
        // make the signature safe to be included in a url
        $encoded_signature = $this->url_safe_base64_encode($signature);

        // combine the above into a stream name
        $stream_name = create_stream_name($video_path, null, $encoded_signature, $key_pair_id, $expires);
        // url-encode the query string characters to work around a flash player bug
    return encode_query_params($stream_name);
}



function rsa_sha1_sign($policy, $private_key_filename) {
    $signature = "";

    // load the private key
    $fp = fopen($private_key_filename, "r");
    $priv_key = fread($fp, 8192);
    fclose($fp);
    $pkeyid = openssl_get_privatekey($priv_key);

    // compute signature
    openssl_sign($policy, $signature, $pkeyid);

    // free the key from memory
    openssl_free_key($pkeyid);

    return $signature;
}

function url_safe_base64_encode($value) {
    $encoded = base64_encode($value);
    // replace unsafe characters +, = and / with 
    // the safe characters -, _ and ~
    return str_replace(
        array('+', '=', '/'),
        array('-', '_', '~'),
        $encoded);
}

Answer 1

函数 create_stream_name() 在完整示例 (demo.php) 中定义，您可以在 https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/samples/demo-php.zip 下载该示例。完整的示例 linked 位于文档页面的顶部，尽管它在文本 "Signature Code for Video Streaming in PHP." 后面有些模糊 [更新： 它不再模糊，请参阅下面。]

完全披露：我是该文档页面的负责人，所以我会做一些事情让它变得更好：

使完整示例的 link 更容易被发现。 [更新：完整示例的下载 URL 现在在 the documentation page 的顶部更加突出。]
将完整的示例添加到页面，这样您就可以直接在页面上查看和复制它，而不必下载 zip 文件。 [更新： 完整示例现在是 published at the bottom of the documentation page。]

如何在 AWS Cloudfront 中组合流名称？

How to combine stream name in AWS cloudfront?

php

amazon-web-services

sdk

amazon-cloudfront