PHP和OAuth：保护您的API

<?php

// Step 1: 用户被重定向到授权URL
$authorizationUrl = 'https://example.com/oauth/authorize?client_id=YOUR_CLIENT_ID&redirect_uri=YOUR_REDIRECT_URI&response_type=code';
header('Location: ' . $authorizationUrl);
exit;

// Step 2: 授权服务器重定向用户到您的回调URL，并提供授权码
$authorizationCode = $_GET['code'];

// Step 3: 使用授权码获取访问令牌
$tokenUrl = 'https://example.com/oauth/token';
$tokenData = [
    'grant_type' => 'authorization_code',
    'code' => $authorizationCode,
    'redirect_uri' => 'YOUR_REDIRECT_URI',
    'client_id' => 'YOUR_CLIENT_ID',
    'client_secret' => 'YOUR_CLIENT_SECRET'
];
$tokenOptions = [
    'http' => [
        'method' => 'POST',
        'header' => 'Content-type: application/x-www-form-urlencoded',
        'content' => http_build_query($tokenData)
    ]
];
$tokenContext = stream_context_create($tokenOptions);
$tokenResult = file_get_contents($tokenUrl, false, $tokenContext);
$accessToken = json_decode($tokenResult)->access_token;

// Step 4: 使用访问令牌获取用户资源
$userUrl = 'https://example.com/api/user';
$userOptions = [
    'http' => [
        'method' => 'GET',
        'header' => 'Authorization: Bearer ' . $accessToken
    ]
];
$userContext = stream_context_create($userOptions);
$userResult = file_get_contents($userUrl, false, $userContext);
$userData = json_decode($userResult);

// 处理用户数据
echo 'Welcome, ' . $userData->name;

?>