Make OPS bencode libs available

_packages/opsnet-bencode/Bencode.php

@@ -0,0 +1,175 @@
+<?php
+
+namespace OrpheusNET\BencodeTorrent;
+
+class Bencode {
+    protected $data = null;
+
+    /**
+     * Sets the internal data array
+     * @param mixed $data
+     * @throws \RuntimeException
+     */
+    public function setData($data) {
+        $this->data = $data;
+    }
+
+    /**
+     * Given a BEncoded string and decode it
+     * @param string $data
+     * @throws \RuntimeException
+     */
+    public function decodeString(string $data) {
+        $this->data = $this->decode($data);
+    }
+
+    /**
+     * Given a path to a file, decode the contents of it
+     *
+     * @param string $path
+     * @throws \RuntimeException
+     */
+    public function decodeFile(string $path) {
+        $this->data = $this->decode(file_get_contents($path, FILE_BINARY));
+    }
+
+    /**
+     * Decodes a BEncoded string to the following values:
+     * - Dictionary (starts with d, ends with e)
+     * - List (starts with l, ends with e
+     * - Integer (starts with i, ends with e
+     * - String (starts with number denoting number of characters followed by : and then the string)
+     *
+     * @see https://wiki.theory.org/index.php/BitTorrentSpecification
+     *
+     * @param string $data
+     * @param int    $pos
+     * @return mixed
+     */
+    protected function decode(string $data, int &$pos = 0) {
+        $start_decode = $pos === 0;
+        if ($data[$pos] === 'd') {
+            $pos++;
+            $return = [];
+            while ($data[$pos] !== 'e') {
+                $key = $this->decode($data, $pos);
+                $value = $this->decode($data, $pos);
+                if ($key === null || $value === null) {
+                    break;
+                }
+                if (!is_string($key)) {
+                    throw new \RuntimeException('Invalid key type, must be string: '.gettype($key));
+                }
+                $return[$key] = $value;
+            }
+            ksort($return);
+            $pos++;
+        }
+        elseif ($data[$pos] === 'l') {
+            $pos++;
+            $return = [];
+            while ($data[$pos] !== 'e') {
+                $value = $this->decode($data, $pos);
+                $return[] = $value;
+            }
+            $pos++;
+        }
+        elseif ($data[$pos] === 'i') {
+            $pos++;
+            $digits = strpos($data, 'e', $pos) - $pos;
+            $return = substr($data, $pos, $digits);
+            if ($return === '-0') {
+                throw new \RuntimeException('Cannot have integer value -0');
+            }
+            $multiplier = 1;
+            if ($return[0] === '-') {
+                $multiplier = -1;
+                $return = substr($return, 1);
+            }
+            if (!ctype_digit($return)) {
+                $msg = 'Cannot have non-digit values in integer number: '.$return;
+                throw new \RuntimeException($msg);
+            }
+            $return = $multiplier * ((int) $return);
+            $pos += $digits + 1;
+        }
+        else {
+            $digits = strpos($data, ':', $pos) - $pos;
+            $len = (int) substr($data, $pos, $digits);
+            $pos += ($digits + 1);
+            $return = substr($data, $pos, $len);
+            $pos += $len;
+        }
+        if ($start_decode) {
+            if ($pos !== strlen($data)) {
+                throw new \RuntimeException('Could not fully decode bencode string');
+            }
+        }
+        return $return;
+    }
+
+    /**
+     * Get the internal data array
+     * @return mixed
+     */
+    public function getData() {
+        return $this->data;
+    }
+
+    /**
+     * @throws \RuntimeException
+     */
+    protected function hasData() {
+        if ($this->data === null) {
+            throw new \RuntimeException('Must decode proper bencode string first');
+        }
+    }
+
+    /**
+     * @return string
+     */
+    public function getEncode() : string {
+        $this->hasData();
+        return $this->encodeVal($this->data);
+    }
+
+    /**
+     * @param mixed $data
+     * @return string
+     */
+    protected function encodeVal($data) : string {
+        if (is_array($data)) {
+            $return = '';
+            $check = -1;
+            $list = true;
+            foreach ($data as $key => $value) {
+                if ($key !== ++$check) {
+                    $list = false;
+                    break;
+                }
+            }
+
+            if ($list) {
+                $return .= 'l';
+                foreach ($data as $value) {
+                    $return .= $this->encodeVal($value);
+                }
+            }
+            else {
+                $return .= 'd';
+                foreach ($data as $key => $value) {
+                    $return .= $this->encodeVal(strval($key));
+                    $return .= $this->encodeVal($value);
+                }
+            }
+            $return .= 'e';
+        }
+        elseif (is_integer($data)) {
+            $return = 'i'.$data.'e';
+        }
+        else {
+            $return = strlen($data) . ':' . $data;
+        }
+        return $return;
+    }
+}

_packages/opsnet-bencode/BencodeTorrent.php

@@ -0,0 +1,391 @@
+<?php
+
+namespace OrpheusNET\BencodeTorrent;
+
+/**
+ * BEncode service that allows us to encode PHP objects into BEncode and decode
+ * BEncode into PHP objects for torrents. BEncode supports the following PHP objects:
+ *      - Associated Array
+ *      - Lists
+ *      - Strings
+ *      - Integers
+ * with any other type throwing an exception. A list is defined for our purposes
+ * as an array with only numeric keys in perfect order, otherwise we assume it's
+ * an associated array and will encode as a dictionary.
+ *
+ * Additionally, as this is for torrent files, we can make the following assumptions
+ * and requirements:
+ *  1. Top level data structure must be a dictionary
+ *  2. Dictionary must contain an info key
+ * If any of these are violated, then we raise an exception for this particular file.
+ *
+ * @see https://wiki.theory.org/index.php/BitTorrentSpecification
+ *
+ * For Gazelle, this also acts as a unification of the two original BEncode implementations
+ * which were both used in separate areas of the codebase.
+ */
+class BencodeTorrent extends Bencode {
+    const FILELIST_DELIM = 0xF7;
+    private static $utf8_filelist_delim = null;
+
+    public function __construct() {
+        $this->setDelim();
+    }
+
+    /**
+     * Internal function that sets up the filelist_delim character for use. We cannot use encode
+     * and char to set a class constant or variable, so we wait till the class is initialized
+     * for the first time to set it.
+     */
+    private function setDelim() {
+        if (self::$utf8_filelist_delim === null) {
+            self::$utf8_filelist_delim = utf8_encode(chr(self::FILELIST_DELIM));
+        }
+    }
+
+    /**
+     * Sets the internal data array
+     * @param array $data
+     * @throws \RuntimeException
+     */
+    public function setData($data) {
+        parent::setData($data);
+        $this->validate();
+    }
+
+    /**
+     * Given a BEncoded string and decode it
+     * @param string $data
+     * @throws \RuntimeException
+     */
+    public function decodeString(string $data) {
+        parent::decodeString($data);
+        $this->validate();
+    }
+
+    /**
+     * Given a path to a file, decode the contents of it
+     *
+     * @param string $path
+     * @throws \RuntimeException
+     */
+    public function decodeFile(string $path) {
+        parent::decodeFile($path);
+        $this->validate();
+    }
+
+    /**
+     * Validates that the internal data array
+     * @throws \RuntimeException
+     */
+    public function validate() {
+        if (!is_array($this->data)) {
+            throw new \TypeError('Data must be an array');
+        }
+        if (empty($this->data['info'])) {
+            throw new \RuntimeException("Torrent dictionary doesn't have info key");
+        }
+        if (isset($this->data['info']['files'])) {
+            foreach ($this->data['info']['files'] as $file) {
+                $path_key = isset($file['path.utf-8']) ? 'path.utf-8' : 'path';
+                if (isset($file[$path_key])) {
+                    $filter = array_filter(
+                        $file[$path_key],
+                        function ($element) {
+                            return strlen($element) === 0;
+                        }
+                    );
+                    if (count($filter) > 0) {
+                        throw new \RuntimeException('Cannot have empty path for a file');
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Utility function to clean out keys in the data and info dictionaries that we don't need in
+     * our torrent file when we go to store it in the DB or serve it up to the user (with the
+     * expectation that we'll be calling at least setAnnounceUrl(...) when a user asks for a valid
+     * torrent file).
+     *
+     * @return bool flag to indicate if we altered the info dictionary
+     */
+    public function clean() : bool {
+        $this->cleanDataDictionary();
+        return $this->cleanInfoDictionary();
+    }
+
+    /**
+     * Clean out keys within the data dictionary that are not strictly necessary or will be
+     * overwritten dynamically on any downloaded torrent (like announce or comment), so that we
+     * store the smallest encoded string within the database and cuts down on potential waste.
+     */
+    public function cleanDataDictionary() {
+        $allowed_keys = array('encoding', 'info');
+        foreach ($this->data as $key => $value) {
+            if (!in_array($key, $allowed_keys)) {
+                unset($this->data[$key]);
+            }
+        }
+    }
+
+    /**
+     * Cleans out keys within the info dictionary (and would affect the generated info_hash)
+     * that are not standard or expected. We do allow some keys that are not strictly necessary
+     * (primarily the two below), but that's because it's better to just have the extra bits in
+     * the dictionary than having to force a user to re-download the torrent file for something
+     * that they might have no idea their client is doing nor how to stop it. Returns TRUE if
+     * we had to change something in the info dictionary that would affect the info_hash (thus
+     * requiring a re-download), else return FALSE.
+     *
+     * x_cross_seed is added by PyroCor (@see https://github.com/pyroscope/pyrocore)
+     * unique is added by xseed (@see https://whatbox.ca/wiki/xseed)
+     *
+     * @return bool
+     */
+    public function cleanInfoDictionary() : bool {
+        $cleaned = false;
+        $allowed_keys = array('files', 'name', 'piece length', 'pieces', 'private', 'length',
+                              'name.utf8', 'name.utf-8', 'md5sum', 'sha1', 'source',
+                              'file-duration', 'file-media', 'profiles', 'x_cross_seed', 'unique');
+        foreach ($this->data['info'] as $key => $value) {
+            if (!in_array($key, $allowed_keys)) {
+                unset($this->data['info'][$key]);
+                $cleaned = true;
+            }
+        }
+
+        return $cleaned;
+    }
+
+    /**
+     * Returns a bool on whether the private flag set to 1 within the info dictionary.
+     *
+     * @return bool
+     */
+    public function isPrivate() : bool {
+        $this->hasData();
+        return isset($this->data['info']['private']) && $this->data['info']['private'] === 1;
+    }
+
+    /**
+     * Sets the private flag (if not already set) in the info dictionary. Setting this to 1 makes
+     * it so a client will only publish its presence in the swarm via the tracker in the announce
+     * URL, else it'll be discoverable via other means such as PEX peer exchange or dht, which is
+     * a negative for security and privacy of a private swarm. Returns a bool on whether or not
+     * the flag was changed so that an appropriate screen can be shown to the user.
+     *
+     * @return bool
+     */
+    public function makePrivate() : bool {
+        $this->hasData();
+        if ($this->isPrivate()) {
+            return false;
+        }
+        $this->data['info']['private'] = 1;
+        ksort($this->data['info']);
+        return true;
+    }
+
+    /**
+     * Set the source flag in the info dictionary equal to $source. This can be used to ensure a
+     * unique info hash across sites so long as all sites use the source flag. This isn't an
+     * 'official' flag (no accepted BEP on it), but it has become the defacto standard with more
+     * clients supporting it natively. Returns a boolean on whether or not the source was changed
+     * so that an appropriate screen can be shown to the user.
+     *
+     * @param string $source
+     *
+     * @return bool true if the source was set/changed, false if no change
+     */
+    public function setSource(string $source) : bool {
+        $this->hasData();
+        if (isset($this->data['info']['source']) && $this->data['info']['source'] === $source) {
+            return false;
+        }
+        // Since we've set the source and will require a re-download, we might as well clean
+        // these out as well
+        unset($this->data['info']['x_cross_seed']);
+        unset($this->data['info']['unique']);
+        $this->setValue(['info.source' => $source]);
+        return true;
+    }
+
+    /**
+     * Function to allow you set any number of keys and values in the data dictionary. You can
+     * set the value in a dictionary by concatenating the keys into a string with a period
+     * separator (ex: info.name will set name field in the info dictionary) so that the rest
+     * of the dictionary is unaffected.
+     *
+     * @param array $array
+     */
+    public function setValue(array $array) {
+        foreach ($array as $key => $value) {
+            if (is_array($value)) {
+                ksort($value);
+            }
+            $keys = explode('.', $key);
+            $data = &$this->data;
+            for ($i = 0; $i < count($keys); $i++) {
+                $data = &$data[$keys[$i]];
+            }
+            $data = $value;
+            $data = &$this->data;
+            for ($i = 0; $i < count($keys); $i++) {
+                $data = &$data[$keys[$i]];
+                if (is_array($data)) {
+                    ksort($data);
+                }
+            }
+        }
+        ksort($this->data);
+        $this->validate();
+    }
+
+    /**
+     * Get a sha1 encoding of the BEncoded info dictionary. The SHA1 encoding allows us to transmit
+     * the info dictionary over the wire (such as within URLs or in submitted forms). Gazelle
+     * primarily relies on this so that it can ensure that all torrents uploaded have unique
+     * info hashes and so a user could search for a torrent based on its info hash. The
+     * BitTorrent protocol uses this when announcing/scraping a torrent so that the tracker can
+     * identify the torrent the client is talking about.
+     *
+     * @return string
+     */
+    public function getInfoHash() : string {
+        $this->hasData();
+        return sha1($this->encodeVal($this->data['info']));
+    }
+
+    public function getHexInfoHash(): string {
+        return pack('H*', $this->getInfoHash());
+    }
+
+    /**
+     * @return string
+     */
+    public function getName() {
+        if (isset($this->data['info']['name.utf-8'])) {
+            return $this->data['info']['name.utf-8'];
+        }
+        return $this->data['info']['name'];
+    }
+
+    /**
+     * Get the total size in bytes of the files in the torrent. For a single file torrent, it'll
+     * just be the 'length' key in the 'info' dictionary, else we iterate through the 'files' list
+     * and add up the 'length' of each element.
+     *
+     * @return int
+     */
+    public function getSize() : int {
+        $cur_size = 0;
+        if (!isset($this->data['info']['files'])) {
+            $cur_size = $this->data['info']['length'];
+        }
+        else {
+            foreach ($this->data['info']['files'] as $file) {
+                $cur_size += $file['length'];
+            }
+        }
+        return $cur_size;
+    }
+
+    /**
+     * Get an array of files that are in the torrent, where each element is a array that contains
+     * the keys 'name' and 'size'. For single torrent files, then we just take the name and length
+     * keys from the info dictionary. For multiple file torrents, we then iterate through the
+     * 'files' list where each element has 'length' and 'path' (which is a list of all components
+     * of the path, which we can join together with '/').
+     *
+     * @return array
+     */
+    public function getFileList() : array {
+        $files = [];
+        if (!isset($this->data['info']['files'])) {
+            // Single-file torrent
+            $name = (isset($this->data['info']['name.utf-8']) ?
+                $this->data['info']['name.utf-8'] :
+                $this->data['info']['name']);
+            $size = $this->data['info']['length'];
+            $files[] = ['path' => $name, 'size' => $size];
+        }
+        else {
+            $size = 0;
+            foreach ($this->data['info']['files'] as $file) {
+                $size += $file['length'];
+                $path_key = isset($file['path.utf-8']) ? 'path.utf-8' : 'path';
+                $files[] = ['path' => implode('/', $file[$path_key]), 'size' => $file['length']];
+            }
+            usort(
+                $files,
+                function ($a, $b) {
+                    return strnatcasecmp($a['path'], $b['path']);
+                }
+            );
+        }
+        return array('total_size' => $size, 'files' => $files);
+    }
+
+    public function hasFiles(): bool {
+        return isset($this->data['info']['files']);
+    }
+
+    public function hasEncryptedFiles(): bool {
+        return isset($this->data['encrypted_files']);
+    }
+
+    /**
+     * Returns an array of strings formatted to be inserted into a Gazelle database into the table
+     * torrents.FileList which is then used for displaying the table of files to the user when
+     * viewing the group. Format of each string is:
+     * {extension} s{size} {name} {delimiter}
+     * We use the delimiter so that we can split the first three apart via ' ' and that then we
+     * use the delimiter to find where the name ends.
+     *
+     * @return array
+     */
+    public function getGazelleFileList() : array {
+        $files = [];
+        foreach ($this->getFileList()['files'] as $file) {
+            $path = $file['path'];
+            $size = $file['size'];
+            $path = $this->makeUTF8(strtr($path, "\n\r\t", '   '));
+            $ext_pos = strrpos($path, '.');
+            // Should not be $ExtPos !== false. Extension-less files that start with a .
+            // should not get extensions
+            $ext = ($ext_pos ? trim(substr($path, $ext_pos + 1)) : '');
+            $files[] =  sprintf("%s s%ds %s %s", ".$ext", $size, $path, self::$utf8_filelist_delim);
+        }
+        return $files;
+    }
+
+    /**
+     * Given a string, convert it to UTF-8 format, if it's not already in UTF-8.
+     *
+     * @param string $str input to convert to utf-8 format
+     *
+     * @return string
+     */
+    private function makeUTF8(string $str) : string {
+        if (preg_match('//u', $str)) {
+            $encoding = 'UTF-8';
+        }
+        if (empty($encoding)) {
+            $encoding = mb_detect_encoding($str, 'UTF-8, ISO-8859-1');
+        }
+        // Legacy thing for Gazelle, leaving it in, but not going to bother testing
+        // @codeCoverageIgnoreStart
+        if (empty($encoding)) {
+            $encoding = 'ISO-8859-1';
+        }
+        // @codeCoverageIgnoreEnd
+        if ($encoding === 'UTF-8') {
+            return $str;
+        }
+        else {
+            return @mb_convert_encoding($str, 'UTF-8', $encoding);
+        }
+    }
+}