CasperSecurity
<?php
declare(strict_types=1);
namespace PhpMyAdmin;
use DirectoryIterator;
use PhpMyAdmin\Utils\HttpRequest;
use stdClass;
use const DIRECTORY_SEPARATOR;
use const PHP_EOL;
use function array_key_exists;
use function array_shift;
use function basename;
use function bin2hex;
use function count;
use function date;
use function explode;
use function fclose;
use function file_exists;
use function file_get_contents;
use function fopen;
use function fread;
use function fseek;
use function function_exists;
use function gzuncompress;
use function implode;
use function in_array;
use function intval;
use function is_dir;
use function is_file;
use function json_decode;
use function ord;
use function preg_match;
use function str_replace;
use function strlen;
use function strpos;
use function strtolower;
use function substr;
use function trim;
use function unpack;
use function is_bool;
/**
* Git class to manipulate Git data
*/
class Git
{
/**
* Build a Git class
*
* @var Config
*/
private $config;
public function __construct(Config $config)
{
$this->config = $config;
}
/**
* detects if Git revision
*
* @param string $git_location (optional) verified git directory
*/
public function isGitRevision(&$git_location = null): bool
{
// PMA config check
if (! $this->config->get('ShowGitRevision')) {
return false;
}
// caching
if (isset($_SESSION['is_git_revision'])
&& array_key_exists('git_location', $_SESSION)
) {
// Define location using cached value
$git_location = $_SESSION['git_location'];
return $_SESSION['is_git_revision'];
}
// find out if there is a .git folder
// or a .git file (--separate-git-dir)
$git = '.git';
if (is_dir($git)) {
if (! @is_file($git . '/config')) {
$_SESSION['git_location'] = null;
$_SESSION['is_git_revision'] = false;
return false;
}
$git_location = $git;
} elseif (is_file($git)) {
$contents = (string) file_get_contents($git);
$gitmatch = [];
// Matches expected format
if (! preg_match(
'/^gitdir: (.*)$/',
$contents,
$gitmatch
)) {
$_SESSION['git_location'] = null;
$_SESSION['is_git_revision'] = false;
return false;
}
if (! @is_dir($gitmatch[1])) {
$_SESSION['git_location'] = null;
$_SESSION['is_git_revision'] = false;
return false;
}
//Detected git external folder location
$git_location = $gitmatch[1];
} else {
$_SESSION['git_location'] = null;
$_SESSION['is_git_revision'] = false;
return false;
}
// Define session for caching
$_SESSION['git_location'] = $git_location;
$_SESSION['is_git_revision'] = true;
return true;
}
private function readPackFile(string $packFile, int $packOffset): ?string
{
// open pack file
$packFileRes = fopen(
$packFile,
'rb'
);
if ($packFileRes === false) {
return null;
}
// seek to start
fseek($packFileRes, $packOffset);
// parse header
$headerData = fread($packFileRes, 1);
if ($headerData === false) {
return null;
}
$header = ord($headerData);
$type = ($header >> 4) & 7;
$hasnext = ($header & 128) >> 7;
$size = $header & 0xf;
$offset = 4;
while ($hasnext) {
$readData = fread($packFileRes, 1);
if ($readData === false) {
return null;
}
$byte = ord($readData);
$size |= ($byte & 0x7f) << $offset;
$hasnext = ($byte & 128) >> 7;
$offset += 7;
}
// we care only about commit objects
if ($type != 1) {
return null;
}
// read data
$commit = fread($packFileRes, $size);
fclose($packFileRes);
if ($commit === false) {
return null;
}
return $commit;
}
private function getPackOffset(string $packFile, string $hash): ?int
{
// load index
$index_data = @file_get_contents(
$packFile
);
if ($index_data === false) {
return null;
}
// check format
if (substr($index_data, 0, 4) != "\377tOc") {
return null;
}
// check version
$version = unpack('N', substr($index_data, 4, 4));
if ($version[1] != 2) {
return null;
}
// parse fanout table
$fanout = unpack(
'N*',
substr($index_data, 8, 256 * 4)
);
// find where we should search
$firstbyte = intval(substr($hash, 0, 2), 16);
// array is indexed from 1 and we need to get
// previous entry for start
if ($firstbyte == 0) {
$start = 0;
} else {
$start = $fanout[$firstbyte];
}
$end = $fanout[$firstbyte + 1];
// stupid linear search for our sha
$found = false;
$offset = 8 + (256 * 4);
for ($position = $start; $position < $end; $position++) {
$sha = strtolower(
bin2hex(
substr($index_data, $offset + ($position * 20), 20)
)
);
if ($sha == $hash) {
$found = true;
break;
}
}
if (! $found) {
return null;
}
// read pack offset
$offset = 8 + (256 * 4) + (24 * $fanout[256]);
$packOffsets = unpack(
'N',
substr($index_data, $offset + ($position * 4), 4)
);
return $packOffsets[1];
}
/**
* Un pack a commit with gzuncompress
*
* @param string $gitFolder The Git folder
* @param string $hash The commit hash
*
* @return array|false|null
*/
private function unPackGz(string $gitFolder, string $hash)
{
$commit = false;
$gitFileName = $gitFolder . '/objects/'
. substr($hash, 0, 2) . '/' . substr($hash, 2);
if (@file_exists($gitFileName)) {
$commit = @file_get_contents($gitFileName);
if ($commit === false) {
$this->config->set('PMA_VERSION_GIT', 0);
return null;
}
$commitData = gzuncompress($commit);
if ($commitData === false) {
return null;
}
$commit = explode("\0", $commitData, 2);
$commit = explode("\n", $commit[1]);
$_SESSION['PMA_VERSION_COMMITDATA_' . $hash] = $commit;
} else {
$pack_names = [];
// work with packed data
$packs_file = $gitFolder . '/objects/info/packs';
$packs = '';
if (@file_exists($packs_file)) {
$packs = @file_get_contents($packs_file);
}
if ($packs) {
// File exists. Read it, parse the file to get the names of the
// packs. (to look for them in .git/object/pack directory later)
foreach (explode("\n", $packs) as $line) {
// skip blank lines
if (strlen(trim($line)) == 0) {
continue;
}
// skip non pack lines
if ($line[0] !== 'P') {
continue;
}
// parse names
$pack_names[] = substr($line, 2);
}
} else {
// '.git/objects/info/packs' file can be missing
// (at least in mysGit)
// File missing. May be we can look in the .git/object/pack
// directory for all the .pack files and use that list of
// files instead
$dirIterator = new DirectoryIterator(
$gitFolder . '/objects/pack'
);
foreach ($dirIterator as $file_info) {
$file_name = $file_info->getFilename();
// if this is a .pack file
if (! $file_info->isFile() || substr($file_name, -5) !== '.pack'
) {
continue;
}
$pack_names[] = $file_name;
}
}
$hash = strtolower($hash);
foreach ($pack_names as $pack_name) {
$index_name = str_replace('.pack', '.idx', $pack_name);
$packOffset = $this->getPackOffset($gitFolder . '/objects/pack/' . $index_name, $hash);
if ($packOffset === null) {
continue;
}
$commit = $this->readPackFile($gitFolder . '/objects/pack/' . $pack_name, $packOffset);
if ($commit !== null) {
$commit = gzuncompress($commit);
if ($commit !== false) {
$commit = explode("\n", $commit);
}
}
$_SESSION['PMA_VERSION_COMMITDATA_' . $hash] = $commit;
}
}
return $commit;
}
/**
* Extract committer, author and message from commit body
*
* @param array $commit The commit body
*
* @return array<int,array<string,string>|string>
*/
private function extractDataFormTextBody(array $commit): array
{
$author = [
'name' => '',
'email' => '',
'date' => '',
];
$committer = [
'name' => '',
'email' => '',
'date' => '',
];
do {
$dataline = array_shift($commit);
$datalinearr = explode(' ', $dataline, 2);
$linetype = $datalinearr[0];
if (! in_array($linetype, ['author', 'committer'])) {
continue;
}
$user = $datalinearr[1];
preg_match('/([^<]+)<([^>]+)> ([0-9]+)( [^ ]+)?/', $user, $user);
$user2 = [
'name' => trim($user[1]),
'email' => trim($user[2]),
'date' => date('Y-m-d H:i:s', (int) $user[3]),
];
if (isset($user[4])) {
$user2['date'] .= $user[4];
}
$$linetype = $user2;
} while ($dataline != '');
$message = trim(implode(' ', $commit));
return [$author, $committer, $message];
}
/**
* Is the commit remote
*
* @param mixed $commit The commit
* @param bool $isRemoteCommit Is the commit remote ?, will be modified by reference
* @param string $hash The commit hash
*
* @return stdClass|null The commit body from the GitHub API
*/
private function isRemoteCommit(&$commit, bool &$isRemoteCommit, string $hash): ?stdClass
{
$httpRequest = new HttpRequest();
// check if commit exists in Github
if ($commit !== false
&& isset($_SESSION['PMA_VERSION_REMOTECOMMIT_' . $hash])
) {
$isRemoteCommit = $_SESSION['PMA_VERSION_REMOTECOMMIT_' . $hash];
return null;
}
$link = 'https://www.phpmyadmin.net/api/commit/' . $hash . '/';
$is_found = $httpRequest->create($link, 'GET');
if ($is_found === false) {
$isRemoteCommit = false;
$_SESSION['PMA_VERSION_REMOTECOMMIT_' . $hash] = false;
return null;
}
if ($is_found === null) {
// no remote link for now, but don't cache this as GitHub is down
$isRemoteCommit = false;
return null;
}
$isRemoteCommit = true;
$_SESSION['PMA_VERSION_REMOTECOMMIT_' . $hash] = true;
if ($commit === false) {
// if no local commit data, try loading from Github
return json_decode((string) $is_found);
}
return null;
}
private function getHashFromHeadRef(string $gitFolder, string $refHead): array
{
$branch = false;
// are we on any branch?
if (strpos($refHead, '/') === false) {
return [trim($refHead), $branch];
}
// remove ref: prefix
$refHead = substr(trim($refHead), 5);
if (strpos($refHead, 'refs/heads/') === 0) {
$branch = substr($refHead, 11);
} else {
$branch = basename($refHead);
}
$refFile = $gitFolder . '/' . $refHead;
if (@file_exists($refFile)) {
$hash = @file_get_contents($refFile);
if ($hash === false) {
$this->config->set('PMA_VERSION_GIT', 0);
return [null, null];
}
return [trim($hash), $branch];
}
// deal with packed refs
$packedRefs = @file_get_contents($gitFolder . '/packed-refs');
if ($packedRefs === false) {
$this->config->set('PMA_VERSION_GIT', 0);
return [null, null];
}
// split file to lines
$refLines = explode(PHP_EOL, $packedRefs);
foreach ($refLines as $line) {
// skip comments
if ($line[0] === '#') {
continue;
}
// parse line
$parts = explode(' ', $line);
// care only about named refs
if (count($parts) != 2) {
continue;
}
// have found our ref?
if ($parts[1] == $refHead) {
$hash = $parts[0];
break;
}
}
if (! isset($hash)) {
$this->config->set('PMA_VERSION_GIT', 0);
// Could not find ref
return [null, null];
}
return [$hash, $branch];
}
private function getCommonDirContents(string $gitFolder): ?string
{
if (! is_file($gitFolder . '/commondir')) {
return null;
}
$commonDirContents = @file_get_contents($gitFolder . '/commondir');
if ($commonDirContents === false) {
return null;
}
return trim($commonDirContents);
}
/**
* detects Git revision, if running inside repo
*/
public function checkGitRevision(): ?array
{
// find out if there is a .git folder
$gitFolder = '';
if (! $this->isGitRevision($gitFolder)) {
$this->config->set('PMA_VERSION_GIT', 0);
return null;
}
$ref_head = @file_get_contents($gitFolder . '/HEAD');
if (! $ref_head) {
$this->config->set('PMA_VERSION_GIT', 0);
return null;
}
$commonDirContents = $this->getCommonDirContents($gitFolder);
if ($commonDirContents !== null) {
$gitFolder .= DIRECTORY_SEPARATOR . $commonDirContents;
}
[$hash, $branch] = $this->getHashFromHeadRef($gitFolder, $ref_head);
if ($hash === null) {
return null;
}
$commit = false;
if (! preg_match('/^[0-9a-f]{40}$/i', $hash)) {
$commit = false;
} elseif (isset($_SESSION['PMA_VERSION_COMMITDATA_' . $hash])) {
$commit = $_SESSION['PMA_VERSION_COMMITDATA_' . $hash];
} elseif (function_exists('gzuncompress')) {
$commit = $this->unPackGz($gitFolder, $hash);
if ($commit === null) {
return null;
}
}
$is_remote_commit = false;
$commit_json = $this->isRemoteCommit(
$commit, // Will be modified if necessary by the function
$is_remote_commit, // Will be modified if necessary by the function
$hash
);
$is_remote_branch = false;
if ($is_remote_commit && $branch !== false) {
// check if branch exists in Github
if (isset($_SESSION['PMA_VERSION_REMOTEBRANCH_' . $hash])) {
$is_remote_branch = $_SESSION['PMA_VERSION_REMOTEBRANCH_' . $hash];
} else {
$httpRequest = new HttpRequest();
$link = 'https://www.phpmyadmin.net/api/tree/' . $branch . '/';
$is_found = $httpRequest->create($link, 'GET', true);
if (is_bool($is_found)) {
$is_remote_branch = $is_found;
$_SESSION['PMA_VERSION_REMOTEBRANCH_' . $hash] = $is_found;
}
if ($is_found === null) {
// no remote link for now, but don't cache this as Github is down
$is_remote_branch = false;
}
}
}
if ($commit !== false) {
[$author, $committer, $message] = $this->extractDataFormTextBody($commit);
} elseif (isset($commit_json->author, $commit_json->committer, $commit_json->message)) {
$author = [
'name' => $commit_json->author->name,
'email' => $commit_json->author->email,
'date' => $commit_json->author->date,
];
$committer = [
'name' => $commit_json->committer->name,
'email' => $commit_json->committer->email,
'date' => $commit_json->committer->date,
];
$message = trim($commit_json->message);
} else {
$this->config->set('PMA_VERSION_GIT', 0);
return null;
}
$this->config->set('PMA_VERSION_GIT', 1);
return [
'hash' => $hash,
'branch' => $branch,
'message' => $message,
'author' => $author,
'committer' => $committer,
'is_remote_commit' => $is_remote_commit,
'is_remote_branch' => $is_remote_branch,
];
}
}