From 6c7e32c67a135d33593c8412e103fae70dffc905 Mon Sep 17 00:00:00 2001 From: Chad Horohoe Date: Thu, 15 Oct 2015 13:37:01 -0700 Subject: [PATCH] SECURITY: API: Improve validation in chunked uploading This fixes a few shortcomings in the chunked uploader: * Raises an error if offset + chunksize > filesize. * Enforces a minimum chunk size for non-final chunks. * Refuses additional chunks after seeing a final chunk. * Status of a chunked upload in progress is now available with 'checkstatus'. Bug: T91203 Bug: T91205 Change-Id: If33cc99f304aab2486507c7500b4abb06b6b5d70 --- includes/DefaultSettings.php | 8 ++++ includes/GlobalFunctions.php | 5 ++- includes/Setup.php | 9 +++++ includes/api/ApiQuerySiteinfo.php | 1 + includes/api/ApiUpload.php | 78 ++++++++++++++++++++++++++++++++------- 5 files changed, 85 insertions(+), 16 deletions(-) diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php index 5f2e3da..662ffb5 100644 --- a/includes/DefaultSettings.php +++ b/includes/DefaultSettings.php @@ -666,6 +666,14 @@ $wgCopyUploadAsyncTimeout = false; $wgMaxUploadSize = 1024 * 1024 * 100; # 100MB /** + * Minimum upload chunk size, in bytes. When using chunked upload, non-final + * chunks smaller than this will be rejected. May be reduced based on the + * 'upload_max_filesize' or 'post_max_size' PHP settings. + * @since 1.26 + */ +$wgMinUploadChunkSize = 1024; # 1KB + +/** * Point the upload navigation link to an external URL * Useful if you want to use a shared repository by default * without disabling local uploads (use $wgEnableUploads = false for that). diff --git a/includes/GlobalFunctions.php b/includes/GlobalFunctions.php index 27f7cac..90cf9c1 100644 --- a/includes/GlobalFunctions.php +++ b/includes/GlobalFunctions.php @@ -3877,12 +3877,13 @@ function wfMemoryLimit() { * Converts shorthand byte notation to integer form * * @param string $string + * @param int $default Returned if $string is empty * @return int */ -function wfShorthandToInteger( $string = '' ) { +function wfShorthandToInteger( $string = '', $default = -1 ) { $string = trim( $string ); if ( $string === '' ) { - return -1; + return $default; } $last = $string[strlen( $string ) - 1]; $val = intval( $string ); diff --git a/includes/Setup.php b/includes/Setup.php index c5382d7..543b6a8 100644 --- a/includes/Setup.php +++ b/includes/Setup.php @@ -350,6 +350,15 @@ if ( $wgResourceLoaderMaxQueryLength === false ) { $wgResourceLoaderMaxQueryLength = $maxValueLength > 0 ? $maxValueLength : -1; } +// Ensure the minimum chunk size is less than PHP upload limits or the maximum +// upload size. +$wgMinUploadChunkSize = min( + $wgMinUploadChunkSize, + $wgMaxUploadSize, + wfShorthandToInteger( ini_get( 'upload_max_filesize' ), 1e100 ), + wfShorthandToInteger( ini_get( 'post_max_size' ), 1e100) - 1024 # Leave room for other parameters +); + /** * Definitions of the NS_ constants are in Defines.php * @private diff --git a/includes/api/ApiQuerySiteinfo.php b/includes/api/ApiQuerySiteinfo.php index 311438f..5cc0a5d 100644 --- a/includes/api/ApiQuerySiteinfo.php +++ b/includes/api/ApiQuerySiteinfo.php @@ -256,6 +256,7 @@ class ApiQuerySiteinfo extends ApiQueryBase { } $data['maxuploadsize'] = UploadBase::getMaxUploadSize(); + $data['minuploadchunksize'] = (int)$this->getConfig()->get( 'MinUploadChunkSize' ); $data['thumblimits'] = $config->get( 'ThumbLimits' ); $this->getResult()->setIndexedTagName( $data['thumblimits'], 'limit' ); diff --git a/includes/api/ApiUpload.php b/includes/api/ApiUpload.php index ff93cfc..704efd4 100644 --- a/includes/api/ApiUpload.php +++ b/includes/api/ApiUpload.php @@ -81,7 +81,7 @@ class ApiUpload extends ApiBase { // Check if the uploaded file is sane if ( $this->mParams['chunk'] ) { - $maxSize = $this->mUpload->getMaxUploadSize(); + $maxSize = UploadBase::getMaxUploadSize(); if ( $this->mParams['filesize'] > $maxSize ) { $this->dieUsage( 'The file you submitted was too large', 'file-too-large' ); } @@ -201,13 +201,30 @@ class ApiUpload extends ApiBase { private function getChunkResult( $warnings ) { $result = array(); - $result['result'] = 'Continue'; if ( $warnings && count( $warnings ) > 0 ) { $result['warnings'] = $warnings; } + $request = $this->getMain()->getRequest(); $chunkPath = $request->getFileTempname( 'chunk' ); $chunkSize = $request->getUpload( 'chunk' )->getSize(); + $totalSoFar = $this->mParams['offset'] + $chunkSize; + $minChunkSize = $this->getConfig()->get( 'MinUploadChunkSize' ); + + // Sanity check sizing + if ( $totalSoFar > $this->mParams['filesize'] ) { + $this->dieUsage( + 'Offset plus current chunk is greater than claimed file size', 'invalid-chunk' + ); + } + + // Enforce minimum chunk size + if ( $totalSoFar != $this->mParams['filesize'] && $chunkSize < $minChunkSize ) { + $this->dieUsage( + "Minimum chunk size is $minChunkSize bytes for non-final chunks", 'chunk-too-small' + ); + } + if ( $this->mParams['offset'] == 0 ) { try { $filekey = $this->performStash(); @@ -217,22 +234,28 @@ class ApiUpload extends ApiBase { } } else { $filekey = $this->mParams['filekey']; + + // Don't allow further uploads to an already-completed session + $progress = UploadBase::getSessionStatus( $this->getUser(), $filekey ); + if ( !$progress ) { + // Probably can't get here, but check anyway just in case + $this->dieUsage( 'No chunked upload session with this key', 'stashfailed' ); + } elseif ( $progress['result'] !== 'Continue' || $progress['stage'] !== 'uploading' ) { + $this->dieUsage( + 'Chunked upload is already completed, check status for details', 'stashfailed' + ); + } + $status = $this->mUpload->addChunk( $chunkPath, $chunkSize, $this->mParams['offset'] ); if ( !$status->isGood() ) { $this->dieUsage( $status->getWikiText(), 'stashfailed' ); - - return array(); } } // Check we added the last chunk: - if ( $this->mParams['offset'] + $chunkSize == $this->mParams['filesize'] ) { + if ( $totalSoFar == $this->mParams['filesize'] ) { if ( $this->mParams['async'] ) { - $progress = UploadBase::getSessionStatus( $filekey ); - if ( $progress && $progress['result'] === 'Poll' ) { - $this->dieUsage( "Chunk assembly already in progress.", 'stashfailed' ); - } UploadBase::setSessionStatus( $filekey, array( 'result' => 'Poll', @@ -251,21 +274,37 @@ class ApiUpload extends ApiBase { } else { $status = $this->mUpload->concatenateChunks(); if ( !$status->isGood() ) { + UploadBase::setSessionStatus( + $this->getUser(), + $filekey, + array( 'result' => 'Failure', 'stage' => 'assembling', 'status' => $status ) + ); $this->dieUsage( $status->getWikiText(), 'stashfailed' ); - - return array(); } // The fully concatenated file has a new filekey. So remove // the old filekey and fetch the new one. + UploadBase::setSessionStatus( $this->getUser(), $filekey, false ); $this->mUpload->stash->removeFile( $filekey ); $filekey = $this->mUpload->getLocalFile()->getFileKey(); $result['result'] = 'Success'; } + } else { + UploadBase::setSessionStatus( + $this->getUser(), + $filekey, + array( + 'result' => 'Continue', + 'stage' => 'uploading', + 'offset' => $totalSoFar, + 'status' => Status::newGood(), + ) + ); + $result['result'] = 'Continue'; + $result['offset'] = $totalSoFar; } $result['filekey'] = $filekey; - $result['offset'] = $this->mParams['offset'] + $chunkSize; return $result; } @@ -374,6 +413,10 @@ class ApiUpload extends ApiBase { // Chunk upload $this->mUpload = new UploadFromChunks(); if ( isset( $this->mParams['filekey'] ) ) { + if ( $this->mParams['offset'] === 0 ) { + $this->dieUsage( 'Cannot supply a filekey when offset is 0', 'badparams' ); + } + // handle new chunk $this->mUpload->continueChunks( $this->mParams['filename'], @@ -720,8 +763,15 @@ class ApiUpload extends ApiBase { ), 'stash' => false, - 'filesize' => null, - 'offset' => null, + 'filesize' => array( + ApiBase::PARAM_TYPE => 'integer', + ApiBase::PARAM_MIN => 0, + ApiBase::PARAM_MAX => UploadBase::getMaxUploadSize(), + ), + 'offset' => array( + ApiBase::PARAM_TYPE => 'integer', + ApiBase::PARAM_MIN => 0, + ), 'chunk' => array( ApiBase::PARAM_TYPE => 'upload', ), -- 2.6.1