Adding passwords and versionning

includes/auth.php

@@ -0,0 +1,57 @@
+<?php
+require_once __DIR__ . '/../config.php';
+
+define('AUTH_PASSWD_FILE', __DIR__ . '/../auth.passwd');
+
+/**
+ * Returns the active password hash.
+ * auth.passwd (written by the web interface) takes precedence over
+ * the UI_PASS_HASH constant in config.php.
+ */
+function active_pass_hash(): string {
+    if (is_readable(AUTH_PASSWD_FILE)) {
+        return trim(file_get_contents(AUTH_PASSWD_FILE));
+    }
+    return UI_PASS_HASH;
+}
+
+function auth_enabled(): bool {
+    return active_pass_hash() !== '';
+}
+
+function require_login(): void {
+    if (!auth_enabled()) {
+        return;
+    }
+    if (session_status() === PHP_SESSION_NONE) {
+        session_start();
+    }
+    if (empty($_SESSION['authenticated'])) {
+        header('Location: login.php');
+        exit;
+    }
+}
+
+function attempt_login(string $username, string $password): bool {
+    if (!auth_enabled()) {
+        return true;
+    }
+    return $username === UI_USER && password_verify($password, active_pass_hash());
+}
+
+function logout(): void {
+    if (session_status() === PHP_SESSION_NONE) {
+        session_start();
+    }
+    $_SESSION = [];
+    session_destroy();
+}
+
+/**
+ * Hash $new_password and write it to auth.passwd.
+ * Returns true on success, false if the file could not be written.
+ */
+function save_password(string $new_password): bool {
+    $hash = password_hash($new_password, PASSWORD_DEFAULT);
+    return file_put_contents(AUTH_PASSWD_FILE, $hash . PHP_EOL, LOCK_EX) !== false;
+}

includes/footer.php

@@ -0,0 +1,4 @@
+<?php require_once __DIR__ . '/../version.php'; ?>
+<footer>
+  portspoof<span>concentrator</span> &nbsp;·&nbsp; v<?= APP_VERSION ?>
+</footer>

includes/style.php

@@ -86,3 +86,10 @@ button[type=submit]:hover { opacity: .85; }
 .bar { height: 6px; background: var(--accent); border-radius: 3px; min-width: 2px; }
 
 form { max-width: 480px; }
+
+footer {
+  text-align: center; padding: 1.25rem; margin-top: 1rem;
+  font-size: .75rem; color: var(--muted);
+  border-top: 1px solid var(--border);
+}
+footer span { color: var(--accent); }