initial

1 files changed, 252 insertions, 0 deletions

diff --git a/init.php b/init.php
new file mode 100644
index 0000000..47e273b
--- /dev/null
+++ b/init.php
@@ -0,0 +1,252 @@
+<?php
+class Af_Proxy_Http extends Plugin {
+
+	/* @var PluginHost $host */
+	private $host;
+
+	/* @var DiskCache $cache */
+	private $cache;
+
+	function about() {
+		return array(null,
+			"Loads media served over plain HTTP via built-in secure proxy",
+			"fox");
+	}
+
+	private $ssl_known_whitelist = "imgur.com gfycat.com i.reddituploads.com pbs.twimg.com i.redd.it i.sli.mg media.tumblr.com";
+
+	function is_public_method($method) {
+		return $method === "imgproxy";
+	}
+
+	function init($host) {
+		$this->host = $host;
+		$this->cache = new DiskCache("images");
+
+		$host->add_hook($host::HOOK_RENDER_ARTICLE, $this, 150);
+		$host->add_hook($host::HOOK_RENDER_ARTICLE_CDM, $this, 150);
+		$host->add_hook($host::HOOK_ENCLOSURE_ENTRY, $this);
+
+		$host->add_hook($host::HOOK_PREFS_TAB, $this);
+
+		if (empty($_SESSION['af_proxy_http_token']))
+			$_SESSION['af_proxy_http_token'] = bin2hex(get_random_bytes(16));
+	}
+
+	function hook_enclosure_entry($enc) {
+		if (preg_match("/image/", $enc["content_type"])) {
+			$proxy_all = $this->host->get($this, "proxy_all");
+
+			$enc["content_url"] = $this->rewrite_url_if_needed($enc["content_url"], $proxy_all);
+		}
+
+		return $enc;
+	}
+
+	function hook_render_article($article) {
+		return $this->hook_render_article_cdm($article);
+	}
+
+	public function imgproxy() {
+		$url = UrlHelper::validate(clean($_REQUEST["url"]));
+
+		// immediately redirect to original URL if:
+		// - url points back to ourselves
+		// - called without user context
+		// - session-spefific token is invalid
+		if (
+			strpos($url, get_self_url_prefix()) === 0 ||
+			empty($_SESSION["uid"]) ||
+			$_REQUEST['af_proxy_http_token'] != $_SESSION['af_proxy_http_token']) {
+			header("Location: $url");
+			return;
+		}
+
+		$local_filename = sha1($url);
+
+		if ($this->cache->exists($local_filename)) {
+			header("Location: " . $this->cache->get_url($local_filename));
+			return;
+		} else {
+			$data = UrlHelper::fetch(["url" => $url, "max_size" => Config::get(Config::MAX_CACHE_FILE_SIZE)]);
+
+			if ($data) {
+				if ($this->cache->put($local_filename, $data)) {
+					header("Location: " . $this->cache->get_url($local_filename));
+					return;
+				}
+			} else {
+				if (function_exists("imagecreate") && !isset($_REQUEST["text"])) {
+					$img = imagecreate(450, 75);
+
+					/*$bg =*/ imagecolorallocate($img, 255, 255, 255);
+					$textcolor = imagecolorallocate($img, 255, 0, 0);
+
+					imagerectangle($img, 0, 0, 450-1, 75-1, $textcolor);
+
+					imagestring($img, 5, 5, 5, "Proxy request failed", $textcolor);
+					imagestring($img, 5, 5, 30, truncate_middle($url, 46, "..."), $textcolor);
+					imagestring($img, 5, 5, 55, "HTTP Code: ".UrlHelper::$fetch_last_error_code, $textcolor);
+
+					header("Content-type: image/png");
+					print imagepng($img);
+					imagedestroy($img);
+
+				} else {
+					header("Content-type: text/plain");
+
+					http_response_code(400);
+
+					print "Proxy request failed.\n".
+						"Fetch error ".UrlHelper::$fetch_last_error." (".UrlHelper::$fetch_last_error_code.")\n".
+						"Requested URL: $url";
+				}
+			}
+		}
+	}
+
+	private function rewrite_url_if_needed($url, $all_remote = false) {
+		/* don't rewrite urls pointing to ourselves */
+
+		if (strpos($url, get_self_url_prefix()) === 0)
+			return $url;
+
+		/* we don't need to handle URLs where local cache already exists, tt-rss rewrites those automatically */
+		if (!$this->cache->exists(sha1($url))) {
+
+			$scheme = parse_url($url, PHP_URL_SCHEME);
+
+			if ($all_remote) {
+				$host = parse_url($url, PHP_URL_HOST);
+				$self_host = parse_url(get_self_url_prefix(), PHP_URL_HOST);
+
+				$is_remote = $host != $self_host;
+			} else {
+				$is_remote = false;
+			}
+
+			if (($scheme != 'https' && $scheme != "") || $is_remote) {
+				if (strpos($url, "data:") !== 0) {
+					$parts = parse_url($url);
+
+					foreach (explode(" " , $this->ssl_known_whitelist) as $host) {
+						if (substr(strtolower($parts['host']), -strlen($host)) === strtolower($host)) {
+							$parts['scheme'] = 'https';
+							$url = UrlHelper::build_url($parts);
+							if ($all_remote && $is_remote) {
+								break;
+							} else {
+								return $url;
+							}
+						}
+					}
+
+					return $this->host->get_public_method_url($this, "imgproxy",
+						["url" => $url, "af_proxy_http_token" => $_SESSION["af_proxy_http_token"]]);
+				}
+			}
+		}
+
+		return $url;
+	}
+
+	function hook_render_article_cdm($article, $api_mode = false) {
+
+		$need_saving = false;
+		$proxy_all = $this->host->get($this, "proxy_all");
+
+		$doc = new DOMDocument();
+		if (@$doc->loadHTML('<?xml encoding="UTF-8">' . $article["content"])) {
+			$xpath = new DOMXPath($doc);
+			$imgs = $xpath->query("//img[@src]");
+
+			foreach ($imgs as $img) {
+				$new_src = $this->rewrite_url_if_needed($img->getAttribute("src"), $proxy_all);
+
+				if ($new_src != $img->getAttribute("src")) {
+					$img->setAttribute("src", $new_src);
+					$img->removeAttribute("srcset");
+
+					$need_saving = true;
+				}
+			}
+
+			$vids = $xpath->query("(//video|//picture)");
+
+			foreach ($vids as $vid) {
+				if ($vid->hasAttribute("poster")) {
+					$new_src = $this->rewrite_url_if_needed($vid->getAttribute("poster"), $proxy_all);
+
+					if ($new_src != $vid->getAttribute("poster")) {
+						$vid->setAttribute("poster", $new_src);
+
+						$need_saving = true;
+					}
+				}
+
+				$vsrcs = $xpath->query("source", $vid);
+
+				foreach ($vsrcs as $vsrc) {
+					$new_src = $this->rewrite_url_if_needed($vsrc->getAttribute("src"), $proxy_all);
+
+					if ($new_src != $vsrc->getAttribute("src")) {
+						$vid->setAttribute("src", $new_src);
+
+						$need_saving = true;
+					}
+				}
+			}
+		}
+
+		if ($need_saving) $article["content"] = $doc->saveHTML();
+
+		return $article;
+	}
+
+	function hook_prefs_tab($args) {
+		if ($args != "prefFeeds") return;
+		?>
+
+		<div dojoType="dijit.layout.AccordionPane"
+			title="<i class='material-icons'>extension</i> <?= __('Image proxy settings (af_proxy_http)') ?>">
+
+			<form dojoType="dijit.form.Form">
+
+				<?= \Controls\pluginhandler_tags($this, "save") ?>
+
+				<script type="dojo/method" event="onSubmit" args="evt">
+					evt.preventDefault();
+					if (this.validate()) {
+						xhr.post("backend.php", this.getValues(), (reply) => {
+							Notify.info(reply);
+						})
+					}
+				</script>
+
+				<fieldset>
+					<label class="checkbox">
+						<?= \Controls\checkbox_tag("proxy_all", $this->host->get($this, "proxy_all")) ?>
+						<?=  __("Enable proxy for all remote images.") ?>
+					</label>
+				</fieldset>
+
+				<hr/>
+
+				<?= \Controls\submit_tag(__("Save")) ?>
+			</form>
+		</div>
+		<?php
+	}
+
+	function save() {
+		$proxy_all = checkbox_to_sql_bool($_POST["proxy_all"] ?? "");
+
+		$this->host->set($this, "proxy_all", $proxy_all);
+
+		echo __("Configuration saved");
+	}
+
+	function api_version() {
+		return 2;
+	}
+}