<?php

// CVE Details is a collection of CVEs, taken from the National Vulnerability
// Database (NVD) and other sources like the Exploit DB and Metasploit. The
// website categorizes it by vendor and product and attach the CWE category.
// There is a Atom feed available, but only logged in users can use it,
// it is not reliable and contain no useful information. This bridge create a
// sane feed with additional information like tags and a link to the CWE
// a description of the vulnerability.
class CVEDetailsBridge extends BridgeAbstract {
	const MAINTAINER = 'Aaron Fischer';
	const NAME = 'CVE Details';
	const CACHE_TIMEOUT = 60 * 60 * 6; // 6 hours
	const DESCRIPTION = 'Report new CVE vulnerabilities for a given vendor (and product)';
	const URI = 'https://www.cvedetails.com';

	const PARAMETERS = array(array(
		// The Vendor ID can be taken from the URL
		'vendor_id' => array(
			'name' => 'Vendor ID',
			'type' => 'number',
			'required' => true,
			'exampleValue' => 74, // PHP
		),
		// The optional Product ID can be taken from the URL as well
		'product_id' => array(
			'name' => 'Product ID',
			'type' => 'number',
			'required' => false,
			'exampleValue' => 128, // PHP
		),
	));

	private $html = null;
	private $vendor = '';
	private $product = '';

	// Return the URL to query.
	// Because of the optional product ID, we need to attach it if it is
	// set. The search result page has the exact same structure (with and
	// without the product ID).
	private function _buildURL() {
		$url = self::URI . '/vulnerability-list/vendor_id-' . $this->getInput('vendor_id');
		if ($this->getInput('product_id') !== '') {
			$url .= '/product_id-' . $this->getInput('product_id');
		}
		// Sadly, there is no way (prove me wrong please) to sort the search
		// result by publish date. So the nearest alternative is the CVE
		// number, which should be mostly accurate.
		$url .= '?order=1'; // Order by CVE number DESC

		return $url;
	}

	// Make the actual request to cvedetails.com and stores the response
	// (HTML) for later use and extract vendor and product from it.
	private function _fetchContent() {
		$html = getSimpleHTMLDOM($this->_buildURL());
		$this->html = defaultLinkTo($html, self::URI);

		$vendor = $html->find('#contentdiv > h1 > a', 0);
		if ($vendor == null) {
			returnServerError('Invalid Vendor ID ' .
				$this->getInput('vendor_id') .
				' or Product ID ' .
				$this->getInput('product_id'));
		}
		$this->vendor = $vendor->innertext;

		$product = $html->find('#contentdiv > h1 > a', 1);
		if ($product != null) {
			$this->product = $product->innertext;
		}
	}

	// Build the name of the feed.
	public function getName() {
		if ($this->getInput('vendor_id') == '') {
			return self::NAME;
		}

		if ($this->html == null) {
			$this->_fetchContent();
		}

		$name = 'CVE Vulnerabilities for ' . $this->vendor;
		if ($this->product != '') {
			$name .= '/' . $this->product;
		}

		return $name;
	}

	// Pull the data from the HTML response and fill the items..
	public function collectData() {
		if ($this->html == null) {
			$this->_fetchContent();
		}

		foreach ($this->html->find('#vulnslisttable .srrowns') as $i => $tr) {
			// There are some optional vulnerability types, which will be
			// added to the categories as well as the CWE number -- which is
			// always given.
			$categories = array($this->vendor);
			$enclosures = array();

			$cwe = $tr->find('td', 2)->find('a', 0);
			if ($cwe != null) {
				$cwe = $cwe->innertext;
				$categories[] = 'CWE-' . $cwe;
				$enclosures[] = 'https://cwe.mitre.org/data/definitions/' . $cwe . '.html';
			}
			$c = $tr->find('td', 4)->innertext;
			if (trim($c) != '') {
				$categories[] = $c;
			}
			if ($this->product != '') {
				$categories[] = $this->product;
			}

			// The CVE number itself
			$title = $tr->find('td', 1)->find('a', 0)->innertext;

			$this->items[] = array(
				'uri' => $tr->find('td', 1)->find('a', 0)->href,
				'title' => $title,
				'timestamp' => $tr->find('td', 5)->innertext,
				'content' => $tr->next_sibling()->innertext,
				'categories' => $categories,
				'enclosures' => $enclosures,
				'uid' => $tr->find('td', 1)->find('a', 0)->innertext,
			);

			// We only want to fetch the latest 10 CVEs
			if (count($this->items) >= 10) {
				break;
			}
		}
	}
}