init: 我的博客项目

includes/auth.php

@@ -0,0 +1,42 @@
+<?php
+if (session_status() === PHP_SESSION_NONE) { session_start(); }
+
+function current_user() {
+    if (!empty($_SESSION["user_id"])) {
+        $st = db()->prepare("SELECT * FROM users WHERE id=?");
+        $st->execute([$_SESSION["user_id"]]);
+        return $st->fetch();
+    }
+    return null;
+}
+
+function is_login() {
+    return !empty($_SESSION["user_id"]);
+}
+
+function is_admin() {
+    $u = current_user();
+    return $u && $u["role"] === "admin";
+}
+
+function require_admin() {
+    if (!is_admin()) {
+        header("Location: " . SITE_URL . "login.php");
+        exit;
+    }
+}
+
+function attempt_login($username, $password) {
+    $st = db()->prepare("SELECT * FROM users WHERE username=?");
+    $st->execute([$username]);
+    $user = $st->fetch();
+    if ($user && password_verify($password, $user["password_hash"])) {
+        $_SESSION["user_id"] = $user["id"];
+        return true;
+    }
+    return false;
+}
+
+function logout() {
+    unset($_SESSION["user_id"]);
+}