1. 实验环境

• 服务器环境：Mac + Php + Nginx (以我的环境)
• 客户端：AVPlayer + AVAssetResourceLoader

2. 服务端实现

// private_key.php
<?php
    $token = $_SERVER["HTTP_TOKEN"];
    // 检查是否授权等
    if ( $token == "test" ) {
        $file = "/Users/Shared/nginx/private/keys/test.key"; // key所在的目录或从数据库获取
        header('Content-Description: File Transfer');
        header('Content-Type: application/octet-stream');
        header('Content-Disposition: attachment; filename="'.basename($file).'"');
        header('Expires: 0');
        // header('Cache-Control: must-revalidate');
        header('Pragma: public');
        header('Content-Length: ' . filesize($file));
        readfile($file);    
    } else {
        http_response_code(401);
        header('Content-Type: application/json');
        echo json_encode([
            "code" => 99,
            "result" => NULL,
            "message" => "invalidate username and password"
        ]);
    }
?>

# 在nginx的配置文件nginx.conf内的server块中添加以下配置
rewrite ^/private/keys/(.+?).key$ /private_key.php last;
location / {
    root   /Users/Shared/nginx/www;
    index  index.html index.htm index.php;
}
location ^~ /files {
    root    /Users/Shared/nginx/;
}
location ~ \.php$ {
    root         /Users/Shared/nginx/www;
    fastcgi_pass   127.0.0.1:9000;
    fastcgi_index  index.php;
    fastcgi_param  SCRIPT_FILENAME  /Users/Shared/nginx/www/$fastcgi_script_name;
    include        fastcgi_params;
}

客户端实现

// ViewController.swift
import UIKit
import AVKit
class ViewController: UIViewController {
    let dispatchQueue = DispatchQueue(label: "cn.wessonwu.demos.AVPlayDemo.resourceLoader")

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }

    @IBAction func onPlayPressed(_ sender: Any) {
        let vc = AVPlayerViewController()
        
        let urlAsset = AVURLAsset(url: URL(string: "http://localhost:8080/files/test.m3u8")!)
        urlAsset.resourceLoader.setDelegate(self, queue: dispatchQueue)
        
        let playerItem = AVPlayerItem(asset: urlAsset)
        vc.player = AVPlayer(playerItem: playerItem)
        self.present(vc, animated: true, completion: nil)
    }
    
    func shouldLoadOrRenewRequestedResource(_ loadingRequest: AVAssetResourceLoadingRequest) -> Bool {
        guard let url = loadingRequest.request.url,
            url.pathExtension == "key" else {
            return false
        }
        let keyServerURL = url
        var request = URLRequest(url: keyServerURL)
        request.addValue("test", forHTTPHeaderField: "TOKEN") // 添加验证(该例子只用了简单的验证)
        URLSession.shared.dataTask(with: request) { (data, resp, error) in
            self.dispatchQueue.async {
                if let ckcData = data {
                    loadingRequest.dataRequest?.respond(with: ckcData)
                    loadingRequest.contentInformationRequest?.contentType = AVStreamingKeyDeliveryContentKeyType
                    loadingRequest.finishLoading()
                } else {
                    loadingRequest.finishLoading(with: error)
                }

            }
        }
        .resume()
        return true
    }
    
}

extension ViewController: AVAssetResourceLoaderDelegate {
    func resourceLoader(_ resourceLoader: AVAssetResourceLoader, shouldWaitForLoadingOfRequestedResource loadingRequest: AVAssetResourceLoadingRequest) -> Bool {
        return shouldLoadOrRenewRequestedResource(loadingRequest)
    }
    func resourceLoader(_ resourceLoader: AVAssetResourceLoader, shouldWaitForRenewalOfRequestedResource renewalRequest: AVAssetResourceRenewalRequest) -> Bool {
        return shouldLoadOrRenewRequestedResource(renewalRequest)
    }
}

Enjoy it!!!