diff --git a/.env.dev b/.env.dev
index 7d9a0c82c1..42b4915d5b 100755
--- a/.env.dev
+++ b/.env.dev
@@ -19,3 +19,6 @@ SLOW_PAGE_TIME=1000000
 MAIL_MAILER=smtp
 MAIL_HOST=mailpit
 MAIL_PORT=1025
+
+AWS_ACCESS_KEY_ID=minioadmin
+AWS_SECRET_ACCESS_KEY=minioadmin
diff --git a/.env.example b/.env.example
index d5848b55d2..ab43017eba 100755
--- a/.env.example
+++ b/.env.example
@@ -18,6 +18,8 @@ DB_PASSWORD=secret
 #DB_PORT=
 #DB_USERNAME=
 
+# cdash.php
+
 # How long since the last submission before considering a project inactive.
 # Set to 0 to always show all projects on viewProjects.php.
 #ACTIVE_PROJECT_DAYS=7
@@ -77,6 +79,12 @@ DB_PASSWORD=secret
 # something other than an email address in LDAP.
 #LOGIN_FIELD=Email
 
+# The maximum visibility level for user-created projects on this instance.
+# Instance admins are able to override this setting and set project visibility
+# to anything.  Thus, this setting is only meaningful if USER_CREATE_PROJECTS=true.
+# Options: PUBLIC, PROTECTED, PRIVATE
+# MAX_PROJECT_VISIBILITY=PUBLIC
+
 # Maximum per-project upload quota, in GB
 #MAX_UPLOAD_QUOTA=10
 
@@ -148,6 +156,9 @@ DB_PASSWORD=secret
 # VCS (eg. GitHub) API endpoints.
 #USE_VCS_API=true
 
+# Should normal users be allowed to create projects
+# USER_CREATE_PROJECTS = false
+
 # logging.php
 #LOG_CHANNEL=stack
 
@@ -172,6 +183,33 @@ QUEUE_CONNECTION=database
 # Number of minutes before and idle session is allowed to expire.
 #SESSION_LIFETIME=120
 
+# filesystem.php
+
+# Default filesystem driver for CDash to use.
+# Supported options are 'local' and 's3'.
+#FILESYSTEM_DRIVER=local
+
+# The following env vars are only relevant for S3 support.
+# The name of the bucket that CDash where will store files.
+# AWS_BUCKET=cdash
+
+# The AWS region where this S3 bucket is stored.
+# Otherwise set this to 'local' if you're using MinIO.
+# AWS_REGION=
+
+# Credentials for access to this S3 bucket.
+#AWS_ACCESS_KEY_ID=
+#AWS_SECRET_ACCESS_KEY=
+
+# Set this to true if you're using MinIO
+#AWS_USE_PATH_STYLE_ENDPOINT=false
+
+# URL of your MinIO server (if you're using MinIO). Leave blank otherwise.
+#AWS_ENDPOINT=
+
+# URL of the bucket on your MinIO server (if you're using MinIO). Leave blank otherwise.
+#AWS_URL=
+
 # mail.php
 #MAIL_MAILER=smtp
 #MAIL_HOST=smtp.mailgun.org
@@ -258,12 +296,3 @@ MIX_PUSHER_APP_CLUSTER="${PUSHER_APP_CLUSTER}"
 
 # Whether or not to automatically register new users upon first login
 #SAML2_AUTO_REGISTER_NEW_USERS=false
-
-# Should normal users be allowed to create projects
-# USER_CREATE_PROJECTS = false
-
-# The maximum visibility level for user-created projects on this instance.
-# Instance admins are able to override this setting and set project visibility
-# to anything.  Thus, this setting is only meaningful if USER_CREATE_PROJECTS=true.
-# Options: PUBLIC, PROTECTED, PRIVATE
-# MAX_PROJECT_VISIBILITY=PUBLIC
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7fa8649111..1d2d1046e1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,22 +14,32 @@ jobs:
     env:
       SITENAME: GitHub Actions
       BASE_IMAGE: ${{matrix.base-image}}
+      STORAGE_TYPE: ${{matrix.storage}}
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
         database: ['mysql', 'postgres']
         base-image: ['debian', 'ubi']
+        storage: ['local', 'minio']
+        exclude:
+          - storage: minio
+            base-image: ubi
+          - storage: minio
+            database: mysql
     steps:
       - uses: actions/checkout@v4
       - uses: docker/setup-buildx-action@v3
       - name: Build images
         shell: bash
         run: |
+          if [ "${{matrix.storage}}" == "minio" ]; then
+            extra_args="-f docker/docker-compose.minio.yml"
+          fi
           docker compose \
               -f docker/docker-compose.yml \
               -f docker/docker-compose.dev.yml \
-              -f "docker/docker-compose.${{matrix.database}}.yml" \
+              -f "docker/docker-compose.${{matrix.database}}.yml" ${extra_args} \
               --env-file .env.dev up -d \
               --build \
               --wait
diff --git a/.github/workflows/ctest_driver_script.cmake b/.github/workflows/ctest_driver_script.cmake
index 2678dedd6b..b1f8084453 100644
--- a/.github/workflows/ctest_driver_script.cmake
+++ b/.github/workflows/ctest_driver_script.cmake
@@ -18,6 +18,7 @@ ctest_empty_binary_directory("${CTEST_BINARY_DIRECTORY}")
 set(cfg_options
   "-DCDASH_DIR_NAME="
   "-DCDASH_SERVER=localhost:8080"
+  "-DCDASH_STORAGE_TYPE=${STORAGE_TYPE}"
 )
 
 # Backup .env file
diff --git a/.github/workflows/submit.sh b/.github/workflows/submit.sh
index e5e7d72b70..755e010583 100644
--- a/.github/workflows/submit.sh
+++ b/.github/workflows/submit.sh
@@ -14,6 +14,8 @@ submit_type="${submit_type:-Experimental}"
 
 site="${SITENAME:-$(hostname)}"
 
+storage_type="${STORAGE_TYPE:-local}"
+
 echo "site=$site"
 echo "database=$database"
 echo "ctest_driver=$ctest_driver"
@@ -40,6 +42,7 @@ docker exec cdash bash -c "\
     --schedule-random \
     -DSITENAME=\"${site}\" \
     -DDATABASE=\"${database}\" \
+    -DSTORAGE_TYPE=\"${storage_type}\" \
     -DSUBMIT_TYPE=\"${submit_type}\" \
     -S \"${ctest_driver}\" \
 "
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 527863051c..129d2cdcaf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,6 +10,9 @@ configure_file(
 # to configure the testing install
 set(CDASH_SERVER localhost CACHE STRING "CDash testing server")
 set(CDASH_IMAGE "$ENV{BASE_IMAGE}" CACHE STRING "Docker image name")
+if(NOT DEFINED CDASH_STORAGE_TYPE)
+  set(CDASH_STORAGE_TYPE "local")
+endif()
 
 get_filename_component(CDASH_DIR_NAME_DEFAULT ${CDash_SOURCE_DIR} NAME)
 set(CDASH_DIR_NAME "${CDASH_DIR_NAME_DEFAULT}" CACHE STRING "URL suffix. Ie 'http://<CDASH_SERVER>/<CDASH_DIR_NAME>'")
diff --git a/app/Console/Commands/ValidateXml.php b/app/Console/Commands/ValidateXml.php
index ee84d2b038..0123630fc2 100644
--- a/app/Console/Commands/ValidateXml.php
+++ b/app/Console/Commands/ValidateXml.php
@@ -6,6 +6,8 @@
 use App\Utils\SubmissionUtils;
 use BadMethodCallException;
 use Illuminate\Console\Command;
+use League\Flysystem\UnableToReadFile;
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 
 class ValidateXml extends Command
 {
@@ -69,6 +71,9 @@ public function handle(): int
                 $this->warn("WARNING: Skipped input file '{$input_xml_file}' as validation"
                     . ' of this file format is currently not supported.');
                 $has_skipped = true;
+            } catch (FileNotFoundException|UnableToReadFile $e) {
+                $this->error($e->getMessage());
+                $has_skipped = true;
             }
         }
 
diff --git a/app/Http/Controllers/BuildController.php b/app/Http/Controllers/BuildController.php
index 7814e33965..acb40b2d0d 100644
--- a/app/Http/Controllers/BuildController.php
+++ b/app/Http/Controllers/BuildController.php
@@ -29,7 +29,7 @@
 use Illuminate\Support\Facades\Log;
 use Illuminate\Support\Facades\Storage;
 use Illuminate\View\View;
-use Symfony\Component\HttpFoundation\BinaryFileResponse;
+use Symfony\Component\HttpFoundation\StreamedResponse;
 
 require_once 'include/api_common.php';
 
@@ -829,7 +829,7 @@ public function files(int $build_id): View
             ->with('urls', $urls);
     }
 
-    public function build_file(int $build_id, int $file_id): BinaryFileResponse
+    public function build_file(int $build_id, int $file_id): StreamedResponse
     {
         $this->setBuildById($build_id);
 
@@ -841,10 +841,26 @@ public function build_file(int $build_id, int $file_id): BinaryFileResponse
         $uploadFile = new UploadFile();
         $uploadFile->Id = $file_id;
         $uploadFile->Fill();
-        return response()->file(Storage::path("upload/{$uploadFile->Sha1Sum}"), [
+
+        // The code below satisfies the following requirements:
+        // 1) Render text and images in browser (as opposed to forcing a download).
+        // 2) Download other files to the proper filename (not a numeric identifier).
+        // 3) Support downloading files that are larger than the PHP memory_limit.
+        $fp = Storage::readStream("upload/{$uploadFile->Sha1Sum}");
+        if ($fp === null) {
+            abort(404, 'File not found');
+        }
+        $filename = $uploadFile->Filename;
+        $headers = [
             'Content-Type' => 'text/plain',
             'Content-Disposition' => "inline/attachment; filename={$uploadFile->Filename}",
-        ]);
+        ];
+        return response()->streamDownload(function () use ($fp) {
+            while (!feof($fp)) {
+                echo fread($fp, 1024);
+            }
+            fclose($fp);
+        }, $filename, $headers, 'inline');
     }
 
     public function ajaxBuildNote(): View
diff --git a/app/Http/Controllers/RemoteProcessingController.php b/app/Http/Controllers/RemoteProcessingController.php
index 632f4f114a..4f7613bab4 100644
--- a/app/Http/Controllers/RemoteProcessingController.php
+++ b/app/Http/Controllers/RemoteProcessingController.php
@@ -99,6 +99,7 @@ public function requeueSubmissionFile(): Response
         $filename = request()->string('filename');
         $buildid = request()->integer('buildid');
         $projectid = request()->integer('projectid');
+        $md5 = request()->string('md5');
         if (!Storage::exists("inprogress/{$filename}")) {
             return response('File not found', Response::HTTP_NOT_FOUND);
         }
@@ -112,7 +113,7 @@ public function requeueSubmissionFile(): Response
         // Requeue the file with exponential backoff.
         PendingSubmissions::IncrementForBuildId($buildid);
         $delay = ((int) config('cdash.retry_base')) ** $retry_handler->Retries;
-        ProcessSubmission::dispatch($filename, $projectid, $buildid, md5_file(Storage::path("inbox/{$filename}")))->delay(now()->addSeconds($delay));
+        ProcessSubmission::dispatch($filename, $projectid, $buildid, $md5)->delay(now()->addSeconds($delay));
         return response('OK', Response::HTTP_OK);
     }
 }
diff --git a/app/Http/Controllers/SubmissionController.php b/app/Http/Controllers/SubmissionController.php
index 64a09f67af..7c39c0c562 100644
--- a/app/Http/Controllers/SubmissionController.php
+++ b/app/Http/Controllers/SubmissionController.php
@@ -21,6 +21,8 @@
 use Illuminate\Support\Facades\Log;
 use Illuminate\Support\Facades\Storage;
 use Illuminate\Support\Str;
+use League\Flysystem\UnableToReadFile;
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 use Symfony\Component\HttpKernel\Exception\HttpException;
 
 final class SubmissionController extends AbstractProjectController
@@ -85,23 +87,22 @@ private function submitProcess(): Response
         $authtoken = AuthTokenUtil::getBearerToken();
         $authtoken_hash = $authtoken === null || $authtoken === '' ? '' : AuthTokenUtil::hashToken($authtoken);
 
-        // Save the incoming file in the inbox directory.
-        $filename = "{$projectname}_-_{$authtoken_hash}_-_" . Str::uuid()->toString() . "_-_{$expected_md5}.xml";
-        $fp = request()->getContent(true);
-        if (!Storage::put("inbox/{$filename}", $fp)) {
-            Log::error("Failed to save submission to inbox for $projectname (md5=$expected_md5)");
-            abort(Response::HTTP_INTERNAL_SERVER_ERROR, 'Failed to save submission file.');
-        }
-
         // Check that the md5sum of the file matches what we were told to expect.
+        $fp = request()->getContent(true);
         if (strlen($expected_md5) > 0) {
-            $md5sum = md5_file(Storage::path("inbox/{$filename}"));
+            $md5sum = SubmissionUtils::hashFileHandle($fp, 'md5');
             if ($md5sum != $expected_md5) {
-                Storage::delete("inbox/{$filename}");
                 abort(Response::HTTP_BAD_REQUEST, "md5 mismatch. expected: {$expected_md5}, received: {$md5sum}");
             }
         }
 
+        // Save the incoming file in the inbox directory.
+        $filename = "{$projectname}_-_{$authtoken_hash}_-_" . Str::uuid()->toString() . "_-_{$expected_md5}.xml";
+        if (!Storage::put("inbox/{$filename}", $fp)) {
+            Log::error("Failed to save submission to inbox for $projectname (md5=$expected_md5)");
+            abort(Response::HTTP_INTERNAL_SERVER_ERROR, 'Failed to save submission file.');
+        }
+
         // Check if we can connect to the database before proceeding any further.
         try {
             DB::connection()->getPdo();
@@ -138,7 +139,7 @@ private function submitProcess(): Response
         $stored_filename = 'inbox/' . $filename;
         $xml_info = [];
         try {
-            $xml_info = SubmissionUtils::get_xml_type(fopen(Storage::path($stored_filename), 'r'), $stored_filename);
+            $xml_info = SubmissionUtils::get_xml_type(Storage::readStream($stored_filename), $stored_filename);
         } catch (BadSubmissionException $e) {
             $xml_info['xml_handler'] = '';
             $message = "Could not determine submission file type for: '{$stored_filename}'";
@@ -149,7 +150,15 @@ private function submitProcess(): Response
         }
         if ($xml_info['xml_handler'] !== '') {
             // If validation is enabled and if this file has a corresponding schema, validate it
-            $validation_errors = $xml_info['xml_handler']::validate(storage_path('app/' . $stored_filename));
+            $validation_errors = [];
+            try {
+                $validation_errors = $xml_info['xml_handler']::validate($stored_filename);
+            } catch (FileNotFoundException|UnableToReadFile $e) {
+                Log::warning($e->getMessage());
+                if ((bool) config('cdash.validate_xml_submissions') === true) {
+                    abort(400, "XML validation failed for $filename:" . PHP_EOL . $e->getMessage());
+                }
+            }
             if (count($validation_errors) > 0) {
                 $error_string = implode(PHP_EOL, $validation_errors);
 
@@ -233,18 +242,24 @@ public function storeUploadedFile(Request $request): Response
         }
 
         try {
-            $sha1sum = decrypt($request->input('sha1sum'));
+            $expected_sha1sum = decrypt($request->input('sha1sum'));
         } catch (DecryptException $e) {
             return response('This feature is disabled', Response::HTTP_CONFLICT);
         }
 
         $uploaded_file = array_values(request()->allFiles())[0];
-        $stored_path = $uploaded_file->storeAs('upload', $sha1sum);
+        $stored_path = $uploaded_file->storeAs('upload', $expected_sha1sum);
         if ($stored_path === false) {
             abort(Response::HTTP_INTERNAL_SERVER_ERROR, 'Failed to store uploaded file');
         }
 
-        if (sha1_file(Storage::path($stored_path)) !== $sha1sum) {
+        $fp = Storage::readStream($stored_path);
+        if ($fp === null) {
+            abort(Response::HTTP_INTERNAL_SERVER_ERROR, 'Failed to store uploaded file');
+        }
+
+        $found_sha1sum = SubmissionUtils::hashFileHandle($fp, 'sha1');
+        if ($found_sha1sum !== $expected_sha1sum) {
             Storage::delete($stored_path);
             return response('Uploaded file does not match expected sha1sum', Response::HTTP_BAD_REQUEST);
         }
diff --git a/app/Jobs/ProcessSubmission.php b/app/Jobs/ProcessSubmission.php
index 997100500c..6abdb5ee21 100644
--- a/app/Jobs/ProcessSubmission.php
+++ b/app/Jobs/ProcessSubmission.php
@@ -99,6 +99,7 @@ private function requeueSubmissionFile($buildid): bool
                 'filename' => $this->filename,
                 'buildid' => $buildid,
                 'projectid' => $this->projectid,
+                'md5' => $this->expected_md5,
             ]);
             if ($this->localFilename !== '') {
                 unlink($this->localFilename);
@@ -107,7 +108,7 @@ private function requeueSubmissionFile($buildid): bool
             return $response->ok();
         } else {
             // Increment retry count.
-            $retry_handler = new RetryHandler(Storage::path("inprogress/{$this->filename}"));
+            $retry_handler = new RetryHandler("inprogress/{$this->filename}");
             $retry_handler->increment();
 
             // Move file back to inbox.
@@ -119,9 +120,9 @@ private function requeueSubmissionFile($buildid): bool
             if (config('queue.default') === 'sqs-fifo') {
                 // Special handling for sqs-fifo, which does not support per-message delays.
                 sleep(10);
-                self::dispatch($this->filename, $this->projectid, $buildid, md5_file(Storage::path("inbox/{$this->filename}")));
+                self::dispatch($this->filename, $this->projectid, $buildid, $this->expected_md5);
             } else {
-                self::dispatch($this->filename, $this->projectid, $buildid, md5_file(Storage::path("inbox/{$this->filename}")))->delay(now()->addSeconds($delay));
+                self::dispatch($this->filename, $this->projectid, $buildid, $this->expected_md5)->delay(now()->addSeconds($delay));
             }
 
             return true;
@@ -215,8 +216,13 @@ private function doSubmit($filename, $projectid, $buildid = null, $expected_md5
             return $handler;
         }
 
-        // Parse the XML file
-        $handler = ctest_parse($filehandle, $filename, $projectid, $expected_md5, $buildid);
+        // Special handling for unparsed (non-XML) submissions.
+        $handler = parse_put_submission($filename, $projectid, $expected_md5, $buildid);
+        if ($handler === false) {
+            // Otherwise, parse this submission as CTest XML.
+            $handler = ctest_parse($filehandle, $filename, $projectid, $expected_md5, $buildid);
+        }
+
         fclose($filehandle);
         unset($filehandle);
 
@@ -293,7 +299,7 @@ private function getSubmissionFileHandle($filename)
         if ((bool) config('cdash.remote_workers') && is_string($filename)) {
             return $this->getRemoteSubmissionFileHandle($filename);
         } elseif (Storage::exists($filename)) {
-            return fopen(Storage::path($filename), 'r');
+            return Storage::readStream($filename);
         } else {
             \Log::error('Failed to get a file handle for submission (was type ' . gettype($filename) . ')');
             return false;
diff --git a/app/Utils/SubmissionUtils.php b/app/Utils/SubmissionUtils.php
index 6ca95f6ffc..69f46a231a 100644
--- a/app/Utils/SubmissionUtils.php
+++ b/app/Utils/SubmissionUtils.php
@@ -300,4 +300,13 @@ public static function compute_error_difference($buildid, $previousbuildid, $war
         }
         $pdo->commit();
     }
+
+    /** Return the hash of an open file handle */
+    public static function hashFileHandle(mixed $filehandle, string $algo): string
+    {
+        $hashContext = hash_init($algo);
+        hash_update_stream($hashContext, $filehandle);
+        rewind($filehandle);
+        return hash_final($hashContext);
+    }
 }
diff --git a/app/Utils/UnparsedSubmissionProcessor.php b/app/Utils/UnparsedSubmissionProcessor.php
index d33058aeb8..91372a4c0b 100644
--- a/app/Utils/UnparsedSubmissionProcessor.php
+++ b/app/Utils/UnparsedSubmissionProcessor.php
@@ -321,7 +321,7 @@ public function populateBuildFileRow(): void
         }
 
         // Check that the md5sum of the file matches what we were expecting.
-        $md5sum = md5_file(Storage::path($this->inboxdatafilename));
+        $md5sum = SubmissionUtils::hashFileHandle(Storage::readStream($this->inboxdatafilename), 'md5');
         if ($md5sum != $this->md5) {
             Storage::delete($this->inboxdatafilename);
             $buildfile->delete();
diff --git a/app/cdash/include/common.php b/app/cdash/include/common.php
index 46af2c030e..91d225685d 100644
--- a/app/cdash/include/common.php
+++ b/app/cdash/include/common.php
@@ -27,6 +27,8 @@
 use Illuminate\Support\Facades\Auth;
 use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Log;
+use League\Flysystem\UnableToReadFile;
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 
 function xslt_process(XSLTProcessor $xsltproc,
     $xml_arg,
@@ -914,20 +916,56 @@ function create_aggregate_build($build, $siteid = null): Build
 }
 
 /**
- * Extract a tarball to a given directory.
+ * Extract a tarball within the local storage directory.
+ *
+ * @throws FileNotFoundException
+ * @throws RuntimeException
+ * @throws UnableToReadFile
  */
-function extract_tar(string $filename, string $dirName): bool
+function extract_tar(string $stored_filepath): string
 {
+    if (!Storage::exists($stored_filepath)) {
+        throw new FileNotFoundException($stored_filepath);
+    }
+
+    // Create a new directory where we can extract the tarball.
+    $localTmpDirPath = 'tmp' . DIRECTORY_SEPARATOR . pathinfo($stored_filepath, PATHINFO_FILENAME);
+    Storage::disk('local')->makeDirectory($localTmpDirPath);
+    $dirName = Storage::disk('local')->path($localTmpDirPath);
+
+    if (config('filesystem.default') !== 'local') {
+        // Download this file to the local Storage tmp dir.
+        $remote_stored_filepath = $stored_filepath;
+        $stored_filepath = 'tmp/' . basename($stored_filepath);
+        $fp = Storage::readStream($remote_stored_filepath);
+        if ($fp === null) {
+            throw UnableToReadFile::fromLocation($remote_stored_filepath);
+        }
+        Storage::disk('local')->put($stored_filepath, $fp);
+    }
+
     try {
-        $tar = new Archive_Tar($filename);
+        $tar = new Archive_Tar(Storage::disk('local')->path($stored_filepath));
         $tar->setErrorHandling(PEAR_ERROR_CALLBACK, function ($pear_error) {
             throw new PEAR_Exception($pear_error->getMessage());
         });
-        return $tar->extract($dirName);
+        $tar_extract_result = $tar->extract($dirName);
+        if (config('filesystem.default') !== 'local') {
+            Storage::disk('local')->delete($stored_filepath);
+        }
+        if ($tar_extract_result === false) {
+            Storage::disk('local')->deleteDirectory($localTmpDirPath);
+            throw new RuntimeException("Unable to extract {$stored_filepath}");
+        }
+        return $dirName;
     } catch (PEAR_Exception $e) {
+        if (config('filesystem.default') !== 'local') {
+            Storage::disk('local')->delete($stored_filepath);
+        }
+        Storage::disk('local')->deleteDirectory($localTmpDirPath);
         report($e);
-        return false;
     }
+    throw new RuntimeException('Unable to determine valid extraction directory');
 }
 
 /**
diff --git a/app/cdash/include/ctestparser.php b/app/cdash/include/ctestparser.php
index 7c3ef8bef4..8c45a50ddf 100644
--- a/app/cdash/include/ctestparser.php
+++ b/app/cdash/include/ctestparser.php
@@ -24,10 +24,6 @@
 use Illuminate\Support\Facades\Log;
 use Illuminate\Support\Facades\Storage;
 
-class CDashParseException extends RuntimeException
-{
-}
-
 /** Determine the descriptive filename for a submission file. */
 function generateBackupFileName($projectname, $subprojectname, $buildname,
     $sitename, $stamp, $fileNameWithExt)
@@ -65,11 +61,11 @@ function generateBackupFileName($projectname, $subprojectname, $buildname,
 }
 
 /** Function to handle new style submissions via HTTP PUT */
-function parse_put_submission($filehandler, $projectid, $expected_md5, ?int $buildid): AbstractSubmissionHandler|false
+function parse_put_submission(string $filename, int $projectid, ?string $expected_md5, ?int $buildid): AbstractSubmissionHandler|false
 {
     $db = Database::getInstance();
 
-    if (!$expected_md5) {
+    if ($expected_md5 === null) {
         return false;
     }
 
@@ -103,10 +99,6 @@ function parse_put_submission($filehandler, $projectid, $expected_md5, ?int $bui
     }
     $sitename = $row['name'];
 
-    // Work directly off the open file handle.
-    $meta_data = stream_get_meta_data($filehandler);
-    $filename = $meta_data['uri'];
-
     // Include the handler file for this type of submission.
     $include_file = 'xml_handlers/' . $buildfile->type . '_handler.php';
     $valid_types = [
@@ -137,17 +129,16 @@ function parse_put_submission($filehandler, $projectid, $expected_md5, ?int $bui
     $build->Id = $buildfile->buildid;
     $handler = new $className($build);
 
-    // Parse the file.
-    if (file_exists($filename)) {
-        $filepath = $filename;
-    } elseif (Storage::exists($filename)) {
-        $filepath = Storage::path($filename);
-    } else {
-        throw new CDashParseException('Failed to locate file ' . $filename);
+    // Make sure the file exists.
+    if (!Storage::exists($filename)) {
+        Log::error("Failed to locate file {$filename}");
+        return false;
     }
 
-    if ($handler->Parse($filepath) === false) {
-        throw new CDashParseException('Failed to parse file ' . $filename);
+    // Parse the file.
+    if ($handler->Parse($filename) === false) {
+        Log::error("Failed to parse file {$filename}");
+        return false;
     }
 
     $buildfile->delete();
@@ -162,19 +153,6 @@ function parse_put_submission($filehandler, $projectid, $expected_md5, ?int $bui
  */
 function ctest_parse($filehandle, string $filename, $projectid, $expected_md5 = '', ?int $buildid = null): AbstractSubmissionHandler|false
 {
-    // Check if this is a new style PUT submission.
-    try {
-        $handler = parse_put_submission($filehandle, $projectid, $expected_md5, $buildid);
-        if ($handler !== false) {
-            return $handler;
-        }
-    } catch (CDashParseException $e) {
-        Log::error($e->getMessage(), [
-            'function' => 'ctest_parse',
-        ]);
-        return false;
-    }
-
     // Try to get the IP of the build.
     $ip = null;
     if (array_key_exists('REMOTE_ADDR', $_SERVER)) {
diff --git a/app/cdash/tests/CMakeLists.txt b/app/cdash/tests/CMakeLists.txt
index 19f8eb7958..44b5f92540 100644
--- a/app/cdash/tests/CMakeLists.txt
+++ b/app/cdash/tests/CMakeLists.txt
@@ -261,7 +261,10 @@ add_unit_test(/CDash/Messaging/Topic/TopicDecorator)
 set_tests_properties(/CDash/Messaging/Topic/TopicDecorator PROPERTIES DEPENDS /CDash/XmlHandler/UpdateHandler)
 
 add_laravel_test(/Feature/RemoteWorkers)
-set_tests_properties(/Feature/RemoteWorkers PROPERTIES DEPENDS /CDash/XmlHandler/UpdateHandler)
+set_tests_properties(/Feature/RemoteWorkers PROPERTIES
+    DEPENDS /CDash/XmlHandler/UpdateHandler
+    DISABLED "$<NOT:$<STREQUAL:${CDASH_STORAGE_TYPE},local>>"
+)
 
 add_laravel_test(/Feature/Jobs/NotifyExpiringAuthTokensTest)
 set_tests_properties(/Feature/Jobs/NotifyExpiringAuthTokensTest PROPERTIES RUN_SERIAL TRUE)
diff --git a/app/cdash/tests/test_donehandler.php b/app/cdash/tests/test_donehandler.php
index 43a8a6c6e9..51b6b66cde 100644
--- a/app/cdash/tests/test_donehandler.php
+++ b/app/cdash/tests/test_donehandler.php
@@ -31,6 +31,11 @@ public function testDoneHandlerLocal()
 
     public function testDoneHandlerRemote()
     {
+        if (config('filesystem.default') !== 'local') {
+            // Skip this test case if we're already testing remote storage.
+            return;
+        }
+
         $this->ConfigFile = dirname(__FILE__) . '/../../../.env';
         $this->Original = file_get_contents($this->ConfigFile);
 
@@ -66,7 +71,7 @@ private function performTest($remote = false)
         $this->assertTrue($build->Id > 0);
 
         // Generate a Done.xml file and submit it.
-        $tmpfname = tempnam(Storage::path('inbox'), 'Done');
+        $tmpfname = tempnam(Storage::disk('local')->path('tmp'), 'Done');
         $handle = fopen($tmpfname, 'w');
         fwrite($handle, "<?xml version=\"1.0\" encoding=\"UTF-8\"?><Done><buildId>$build->Id</buildId><time>$timestamp</time></Done>");
         fclose($handle);
@@ -103,8 +108,7 @@ private function performTest($remote = false)
             }
         }
 
-        $files = Storage::files('parsed');
-        $contents = file_get_contents(Storage::path($files[0]));
+        $contents = Storage::get(Storage::files('parsed')[0]);
         $this->assertTrue(str_contains($contents, 'Done retries="5"'));
 
         unlink($tmpfname);
diff --git a/app/cdash/tests/test_extracttar.php b/app/cdash/tests/test_extracttar.php
index f1270f04cc..8271702f70 100644
--- a/app/cdash/tests/test_extracttar.php
+++ b/app/cdash/tests/test_extracttar.php
@@ -1,5 +1,8 @@
 <?php
 
+use League\Flysystem\UnableToReadFile;
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
+
 class ExtractTarTestCase extends KWWebTestCase
 {
     public function __construct()
@@ -9,14 +12,14 @@ public function __construct()
 
     public function testExtractTarArchiveTarWithInvalidFile()
     {
-        $result = extract_tar(dirname(__FILE__) . '/../config/config.php', 'foo');
-
-        $this->assertFalse($result);
-        $this->assertTrue(is_readable($this->logfilename));
-
-        $logfileContents = file_get_contents($this->logfilename);
-
-        $this->assertTrue($this->findString($logfileContents, 'ERROR'));
-        $this->assertTrue($this->findString($logfileContents, 'extract_tar'));
+        $exception_thrown = false;
+        try {
+            extract_tar('this_file_does_not_exist');
+        } catch (FileNotFoundException|UnableToReadFile $e) {
+            $exception_thrown = true;
+        }
+        if (!$exception_thrown) {
+            $this->fail('No Exception thrown when expected');
+        }
     }
 }
diff --git a/app/cdash/tests/test_uploadfile.php b/app/cdash/tests/test_uploadfile.php
index cda9e37c05..34a74066c5 100644
--- a/app/cdash/tests/test_uploadfile.php
+++ b/app/cdash/tests/test_uploadfile.php
@@ -6,6 +6,7 @@
 //
 require_once dirname(__FILE__) . '/cdash_test_case.php';
 
+use App\Utils\SubmissionUtils;
 use Illuminate\Support\Facades\Storage;
 
 class UploadFileTestCase extends KWWebTestCase
@@ -63,8 +64,8 @@ public function testVerifyFileSubmission()
         $this->FileId = $query[0]['id'];
         $this->Sha1Sum = $query[0]['sha1sum'];
 
-        $uploaded_filepath = Storage::path('upload') . "/{$this->Sha1Sum}";
-        if (!file_exists($uploaded_filepath)) {
+        $uploaded_filepath = "upload/{$this->Sha1Sum}";
+        if (!Storage::exists($uploaded_filepath)) {
             $this->fail("File was not written to $uploaded_filepath");
             return;
         }
@@ -79,12 +80,14 @@ public function testVerifyFileSubmission()
         $body = $response->getBody();
         file_put_contents($tmp_file, $body);
 
-        if (filesize($tmp_file) !== filesize($uploaded_filepath)) {
+        if (filesize($tmp_file) !== Storage::size($uploaded_filepath)) {
             $this->fail('filesize mismatch for downloaded file');
         }
-        if (sha1_file($tmp_file) !== sha1_file($uploaded_filepath)) {
+        if (md5_file($tmp_file) !== SubmissionUtils::hashFileHandle(Storage::readStream($uploaded_filepath), 'md5')) {
             $this->fail("hash mismatch for downloaded file ($tmp_file) vs ($uploaded_filepath)");
         }
+
+        unlink($tmp_file);
     }
 
     // Make sure the build label has been set
diff --git a/app/cdash/xml_handlers/BazelJSON_handler.php b/app/cdash/xml_handlers/BazelJSON_handler.php
index df3255a2c9..3c3d1eddc3 100644
--- a/app/cdash/xml_handlers/BazelJSON_handler.php
+++ b/app/cdash/xml_handlers/BazelJSON_handler.php
@@ -25,6 +25,7 @@
 use CDash\Model\BuildErrorFilter;
 use CDash\Model\Project;
 use Illuminate\Support\Facades\Log;
+use Illuminate\Support\Facades\Storage;
 
 class BazelJSONHandler extends AbstractSubmissionHandler
 {
@@ -90,8 +91,8 @@ public function __construct(Build $build)
      **/
     public function Parse($filename)
     {
-        $handle = fopen($filename, 'r');
-        if (!$handle) {
+        $handle = Storage::readStream($filename);
+        if ($handle === null) {
             Log::error("Could not open $filename for parsing", [
                 'function' => 'BazelJSONHandler::Parse',
             ]);
diff --git a/app/cdash/xml_handlers/BuildPropertiesJSON_handler.php b/app/cdash/xml_handlers/BuildPropertiesJSON_handler.php
index fa3c71e1dd..e48a4f0578 100644
--- a/app/cdash/xml_handlers/BuildPropertiesJSON_handler.php
+++ b/app/cdash/xml_handlers/BuildPropertiesJSON_handler.php
@@ -32,7 +32,14 @@ public function __construct(Build $build)
     public function Parse($filename)
     {
         // Test that this file contains valid JSON that PHP can decode.
-        $json_obj = json_decode(file_get_contents($filename), true);
+        $json_str = Storage::get($filename);
+        if ($json_str === null) {
+            Log::error("Failed to retrieve $filename from Storage", [
+                'function' => 'BuildPropertiesJSONHandler::Parse',
+            ]);
+            return false;
+        }
+        $json_obj = json_decode($json_str, true);
         if ($json_obj === null) {
             $err = json_last_error_msg();
             Log::error("Failed to parse $filename: $err", [
diff --git a/app/cdash/xml_handlers/GcovTar_handler.php b/app/cdash/xml_handlers/GcovTar_handler.php
index b536024b35..43b833d423 100644
--- a/app/cdash/xml_handlers/GcovTar_handler.php
+++ b/app/cdash/xml_handlers/GcovTar_handler.php
@@ -23,8 +23,8 @@
 use CDash\Model\CoverageSummary;
 use CDash\Model\Label;
 use CDash\Model\SubProject;
-use Illuminate\Support\Facades\Log;
-use Illuminate\Support\Facades\Storage;
+use League\Flysystem\UnableToReadFile;
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 
 class GcovTarHandler extends AbstractSubmissionHandler
 {
@@ -65,18 +65,13 @@ public function __construct(Build $build)
     /**
      * Parse a tarball of .gcov files.
      **/
-    public function Parse($filename)
+    public function Parse(string $filename): bool
     {
-        // Create a new directory where we can extract our tarball.
-        $dirName = Storage::path('parsed') . DIRECTORY_SEPARATOR . pathinfo($filename, PATHINFO_FILENAME);
-        mkdir($dirName);
-
         // Extract the tarball.
-        $result = extract_tar($filename, $dirName);
-        if ($result === false) {
-            Log::error('Could not extract ' . $filename . ' into ' . $dirName, [
-                'function' => 'GcovTarHandler::Parse',
-            ]);
+        try {
+            $dirName = extract_tar($filename);
+        } catch (FileNotFoundException|UnableToReadFile|RuntimeException $e) {
+            report($e);
             return false;
         }
 
diff --git a/app/cdash/xml_handlers/JSCoverTar_handler.php b/app/cdash/xml_handlers/JSCoverTar_handler.php
index 5ad16cd1e4..5af38038bb 100644
--- a/app/cdash/xml_handlers/JSCoverTar_handler.php
+++ b/app/cdash/xml_handlers/JSCoverTar_handler.php
@@ -21,8 +21,8 @@
 use CDash\Model\CoverageFileLog;
 use CDash\Model\CoverageSummary;
 use Illuminate\Support\Facades\DB;
-use Illuminate\Support\Facades\Log;
-use Illuminate\Support\Facades\Storage;
+use League\Flysystem\UnableToReadFile;
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 
 class JSCoverTarHandler extends AbstractSubmissionHandler
 {
@@ -45,18 +45,13 @@ public function __construct(Build $build)
     /**
      * Parse a tarball of JSON files.
      **/
-    public function Parse($filename)
+    public function Parse(string $filename): bool
     {
-        // Create a new directory where we can extract our tarball.
-        $dirName = Storage::path('parsed') . DIRECTORY_SEPARATOR . pathinfo($filename, PATHINFO_FILENAME);
-        mkdir($dirName);
-
         // Extract the tarball.
-        $result = extract_tar($filename, $dirName);
-        if ($result === false) {
-            Log::error('Could not extract ' . $filename . ' into ' . $dirName, [
-                'function' => 'JSCoverTarHandler::Parse',
-            ]);
+        try {
+            $dirName = extract_tar($filename);
+        } catch (FileNotFoundException|UnableToReadFile|RuntimeException $e) {
+            report($e);
             return false;
         }
 
diff --git a/app/cdash/xml_handlers/JavaJSONTar_handler.php b/app/cdash/xml_handlers/JavaJSONTar_handler.php
index 2aa0fc2565..4e911fba12 100644
--- a/app/cdash/xml_handlers/JavaJSONTar_handler.php
+++ b/app/cdash/xml_handlers/JavaJSONTar_handler.php
@@ -21,8 +21,8 @@
 use CDash\Model\CoverageFileLog;
 use CDash\Model\CoverageSummary;
 use Illuminate\Support\Facades\DB;
-use Illuminate\Support\Facades\Log;
-use Illuminate\Support\Facades\Storage;
+use League\Flysystem\UnableToReadFile;
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 
 class JavaJSONTarHandler extends AbstractSubmissionHandler
 {
@@ -41,18 +41,13 @@ public function __construct(Build $init)
     /**
      * Parse a tarball of JSON files.
      **/
-    public function Parse($filename)
+    public function Parse(string $filename): bool
     {
-        // Create a new directory where we can extract our tarball.
-        $dirName = Storage::path('parsed') . DIRECTORY_SEPARATOR . pathinfo($filename, PATHINFO_FILENAME);
-        mkdir($dirName);
-
         // Extract the tarball.
-        $result = extract_tar($filename, $dirName);
-        if ($result === false) {
-            Log::error('Could not extract ' . $filename . ' into ' . $dirName, [
-                'function' => 'JavaJSONTarHandler::Parse',
-            ]);
+        try {
+            $dirName = extract_tar($filename);
+        } catch (FileNotFoundException|UnableToReadFile|RuntimeException $e) {
+            report($e);
             return false;
         }
 
diff --git a/app/cdash/xml_handlers/OpenCoverTar_handler.php b/app/cdash/xml_handlers/OpenCoverTar_handler.php
index 1d1d959749..4682aee478 100644
--- a/app/cdash/xml_handlers/OpenCoverTar_handler.php
+++ b/app/cdash/xml_handlers/OpenCoverTar_handler.php
@@ -20,8 +20,8 @@
 use CDash\Model\CoverageFile;
 use CDash\Model\CoverageFileLog;
 use CDash\Model\CoverageSummary;
-use Illuminate\Support\Facades\Log;
-use Illuminate\Support\Facades\Storage;
+use League\Flysystem\UnableToReadFile;
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 
 class OpenCoverTarHandler extends AbstractXmlHandler
 {
@@ -137,23 +137,18 @@ public function text($parser, $data)
     /**
      * Parse a tarball of JSON files.
      **/
-    public function Parse($filename)
+    public function Parse(string $filename): bool
     {
-        // Create a new directory where we can extract our tarball.
-        $dirName = Storage::path('parsed') . DIRECTORY_SEPARATOR . pathinfo($filename, PATHINFO_FILENAME);
-        mkdir($dirName);
-        $this->tarDir = $dirName;
-        $result = extract_tar($filename, $dirName);
-        if ($result === false) {
-            Log::error('Could not extract ' . $filename . ' into ' . $dirName, [
-                'function' => 'OpenCoverTarHandler::Parse',
-            ]);
+        try {
+            $this->tarDir = extract_tar($filename);
+        } catch (FileNotFoundException|UnableToReadFile|RuntimeException $e) {
+            report($e);
             return false;
         }
 
         // Search for data.json
         $iterator = new RecursiveIteratorIterator(
-            new RecursiveDirectoryIterator($dirName),
+            new RecursiveDirectoryIterator($this->tarDir),
             RecursiveIteratorIterator::CHILD_FIRST);
         foreach ($iterator as $fileinfo) {
             if ($fileinfo->getFilename() == 'data.json') {
@@ -225,7 +220,7 @@ public function Parse($filename)
         }
 
         // Delete the directory when we're done.
-        DeleteDirectory($dirName);
+        DeleteDirectory($this->tarDir);
         return true;
     }
 
diff --git a/app/cdash/xml_handlers/SubProjectDirectories_handler.php b/app/cdash/xml_handlers/SubProjectDirectories_handler.php
index cb6f3261d0..614d9d5b1d 100644
--- a/app/cdash/xml_handlers/SubProjectDirectories_handler.php
+++ b/app/cdash/xml_handlers/SubProjectDirectories_handler.php
@@ -36,13 +36,21 @@ public function __construct(Build|Project $init)
      **/
     public function Parse($filename)
     {
-        $open_list = file($filename, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
-        if ($open_list === false) {
+        $open_list = [];
+        $fp = Storage::readStream($filename);
+        if ($fp === null) {
             Log::error("Could not open $filename for parsing", [
                 'function' => 'SubProjectDirectoriesHandler::Parse',
             ]);
             return false;
         }
+        while (($line = fgets($fp)) !== false) {
+            $line = trim($line);
+            if ($line === '') {
+                continue;
+            }
+            $open_list[] = $line;
+        }
 
         // Record the order that the packages were listed in.
         $order = 1;
diff --git a/app/cdash/xml_handlers/abstract_xml_handler.php b/app/cdash/xml_handlers/abstract_xml_handler.php
index 8bcd1a9ac7..ae636a446e 100644
--- a/app/cdash/xml_handlers/abstract_xml_handler.php
+++ b/app/cdash/xml_handlers/abstract_xml_handler.php
@@ -20,6 +20,9 @@
 use CDash\Model\Build;
 use CDash\Model\Project;
 use CDash\ServiceContainer;
+use Illuminate\Support\Facades\Storage;
+use League\Flysystem\UnableToReadFile;
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 
 abstract class AbstractXmlHandler extends AbstractSubmissionHandler
 {
@@ -43,6 +46,9 @@ public function __construct(Build|Project $init)
      * Validate the given XML file based on its type
      *
      * @return array<string>
+     *
+     * @throws FileNotFoundException
+     * @throws UnableToReadFile
      */
     public static function validate(string $path): array
     {
@@ -50,16 +56,36 @@ public static function validate(string $path): array
             return [];
         }
 
-        $errors = [];
         // let us control the failures so we can continue
         // parsing files instead of crashing midway
         libxml_use_internal_errors(true);
 
         // load the input file to be validated
+        $local_path = '';
         $xml = new DOMDocument();
-        $xml->load($path, LIBXML_PARSEHUGE);
+        if (file_exists($path)) {
+            $xml->load($path, LIBXML_PARSEHUGE);
+        } else {
+            if (!Storage::exists($path)) {
+                throw new FileNotFoundException($path);
+            }
+            if (config('filesystem.default') === 'local') {
+                $xml->load(Storage::path($path), LIBXML_PARSEHUGE);
+            } else {
+                // Temporarily download the file because DOMDocument->load takes a path,
+                // not a stream...
+                $fp = Storage::readStream($path);
+                if ($fp === null) {
+                    throw UnableToReadFile::fromLocation($path);
+                }
+                $local_path = 'tmp/' . basename($path);
+                Storage::disk('local')->put($local_path, $fp);
+                $xml->load(Storage::disk('local')->path($local_path), LIBXML_PARSEHUGE);
+            }
+        }
 
         // run the validator and collect errors if there are any.
+        $errors = [];
         if (!$xml->schemaValidate(base_path(static::$schema_file))) {
             $validation_errors = libxml_get_errors();
             foreach ($validation_errors as $error) {
@@ -70,6 +96,10 @@ public static function validate(string $path): array
             libxml_clear_errors();
         }
 
+        if (config('filesystem.default') !== 'local') {
+            Storage::disk('local')->delete($local_path);
+        }
+
         return $errors;
     }
 
diff --git a/app/cdash/xml_handlers/retry_handler.php b/app/cdash/xml_handlers/retry_handler.php
index 77f9fc1407..07f83569b7 100644
--- a/app/cdash/xml_handlers/retry_handler.php
+++ b/app/cdash/xml_handlers/retry_handler.php
@@ -33,11 +33,16 @@ public function __construct($filename)
      **/
     public function increment()
     {
-        if (!file_exists($this->FileName)) {
+        if (!Storage::exists($this->FileName)) {
             return false;
         }
 
-        $xml = simplexml_load_file($this->FileName);
+        $contents = Storage::get($this->FileName);
+        if ($contents === null) {
+            return false;
+        }
+
+        $xml = simplexml_load_string($contents);
         $attributes = $xml->attributes();
         if (isset($attributes['retries'])) {
             $this->Retries = intval($attributes['retries']) + 1;
@@ -46,6 +51,6 @@ public function increment()
         }
         $xml['retries'] = $this->Retries;
 
-        return $xml->asXML($this->FileName);
+        return Storage::put($this->FileName, $xml->asXML());
     }
 }
diff --git a/composer.json b/composer.json
index 6df571f692..f87f2fcc5f 100644
--- a/composer.json
+++ b/composer.json
@@ -33,6 +33,7 @@
     "laravel/socialite": "5.16.1",
     "laravel/ui": "4.6.0",
     "lcobucci/jwt": "5.4.2",
+    "league/flysystem-aws-s3-v3": "^3.29",
     "mll-lab/laravel-graphiql": "3.2.1",
     "nuwave/lighthouse": "6.47.0",
     "pear/archive_tar": "1.5.0",
diff --git a/composer.lock b/composer.lock
index 5f20ef99a3..8af94ffeda 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "3182e69a75a77c79a2211cc99d90e44c",
+    "content-hash": "1d62081b6e5763ae0d198716bea6edb1",
     "packages": [
         {
             "name": "24slides/laravel-saml2",
@@ -2947,6 +2947,61 @@
             },
             "time": "2024-10-08T08:58:34+00:00"
         },
+        {
+            "name": "league/flysystem-aws-s3-v3",
+            "version": "3.29.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/thephpleague/flysystem-aws-s3-v3.git",
+                "reference": "c6ff6d4606e48249b63f269eba7fabdb584e76a9"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/thephpleague/flysystem-aws-s3-v3/zipball/c6ff6d4606e48249b63f269eba7fabdb584e76a9",
+                "reference": "c6ff6d4606e48249b63f269eba7fabdb584e76a9",
+                "shasum": ""
+            },
+            "require": {
+                "aws/aws-sdk-php": "^3.295.10",
+                "league/flysystem": "^3.10.0",
+                "league/mime-type-detection": "^1.0.0",
+                "php": "^8.0.2"
+            },
+            "conflict": {
+                "guzzlehttp/guzzle": "<7.0",
+                "guzzlehttp/ringphp": "<1.1.1"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "League\\Flysystem\\AwsS3V3\\": ""
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Frank de Jonge",
+                    "email": "info@frankdejonge.nl"
+                }
+            ],
+            "description": "AWS S3 filesystem adapter for Flysystem.",
+            "keywords": [
+                "Flysystem",
+                "aws",
+                "file",
+                "files",
+                "filesystem",
+                "s3",
+                "storage"
+            ],
+            "support": {
+                "source": "https://github.com/thephpleague/flysystem-aws-s3-v3/tree/3.29.0"
+            },
+            "time": "2024-08-17T13:10:48+00:00"
+        },
         {
             "name": "league/flysystem-local",
             "version": "3.29.0",
diff --git a/config/filesystems.php b/config/filesystems.php
index 8e7200ffc7..173257e057 100755
--- a/config/filesystems.php
+++ b/config/filesystems.php
@@ -58,8 +58,17 @@
             'key' => env('AWS_ACCESS_KEY_ID'),
             'secret' => env('AWS_SECRET_ACCESS_KEY'),
             'region' => env('AWS_DEFAULT_REGION'),
-            'bucket' => env('AWS_BUCKET'),
+            'bucket' => env('AWS_BUCKET', 'cdash'),
             'url' => env('AWS_URL'),
+            'endpoint' => env('AWS_ENDPOINT'),
+            'use_path_style_endpoint' => env('AWS_USE_PATH_STYLE_ENDPOINT', false),
+            // N.B. Laravel downloads files from S3 to a temporary directory on the
+            // local file system before serving them to clients!
+            // Setting 'stream_reads=true' would allow us to stream from S3 directly,
+            // but we can't use it because of our various calls to rewind().
+            // See https://github.com/laravel/framework/discussions/49232
+            // for more details.
+            // 'stream_reads' => true,
         ],
 
         'cdash' => [
diff --git a/docker/docker-compose.minio.yml b/docker/docker-compose.minio.yml
new file mode 100644
index 0000000000..ddc1da7a18
--- /dev/null
+++ b/docker/docker-compose.minio.yml
@@ -0,0 +1,23 @@
+services:
+  cdash:
+    environment:
+      FILESYSTEM_DRIVER: s3
+      AWS_BUCKET: cdash
+      AWS_REGION: local
+      AWS_ACCESS_KEY_ID: ${AWS_ACCESS_KEY_ID}
+      AWS_SECRET_ACCESS_KEY: ${AWS_SECRET_ACCESS_KEY}
+      AWS_USE_PATH_STYLE_ENDPOINT: true
+      AWS_URL: http://minio:9000/cdash/
+      AWS_ENDPOINT: http://minio:9000
+  minio:
+    image: bitnami/minio:latest
+    ports:
+      - "9000:9000"
+    environment:
+      MINIO_DEFAULT_BUCKETS: "cdash"
+      MINIO_ROOT_USER: ${AWS_ACCESS_KEY_ID}
+      MINIO_ROOT_PASSWORD: ${AWS_SECRET_ACCESS_KEY}
+    volumes:
+      - miniodata:/bitnami/minio/data
+volumes:
+  miniodata:
diff --git a/docs/config.md b/docs/config.md
index 6d79c08f29..41f30aa506 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -48,8 +48,6 @@ Please see that file for a full list of configuration options.
 | MAIL_USERNAME | The username used to connect to the SMTP server | '' |
 | MAIL_PASSWORD | The password of the SMTP user | '' |
 
-
-
 ## Authentication
 By default, CDash stores each user's email address and a hash of their password
 in the `user` table. This information is used to authenticate users as they log
@@ -73,6 +71,34 @@ service.
 
 See the [Submissions guide](submissions.md) for more details.
 
+## File Storage
+
+By default, CDash uses the local filesystem to store files it receives from CTest.
+If you're happy with this default, no additional configuration is necessary.
+
+CDash can be configured to use S3 instead, either hosted by AWS or a MinIO server.
+
+The following environment variables are common for both S3 implementations:
+```
+FILESYSTEM_DRIVER=s3
+AWS_ACCESS_KEY_ID=<access key id>
+AWS_SECRET_ACCESS_KEY=<secret access key>
+AWS_BUCKET=<your bucket name> (defaults to 'cdash')
+```
+
+For AWS S3, you will also need to set:
+```
+AWS_REGION=<region>
+```
+
+For MinIO, you should set the following environment variables:
+```
+AWS_REGION=local
+AWS_USE_PATH_STYLE_ENDPOINT=true
+AWS_ENDPOINT=<root Minio URL> (e.g. http://127.0.0.1:9001)
+AWS_URL=<bucket URL> (e.g. http://127.0.0.1:9001/cdash/)
+```
+
 ## Other settings
 | Variable  | Description | Default |
 | --------- | ----------- | ------- |
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 001da5dc4e..a32ba3a2ad 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -5372,6 +5372,11 @@ parameters:
 
 		-
 			message: "#^Parameter \\#1 \\$stream of function rewind expects resource, mixed given\\.$#"
+			count: 2
+			path: app/Utils/SubmissionUtils.php
+
+		-
+			message: "#^Parameter \\#2 \\$stream of function hash_update_stream expects resource, mixed given\\.$#"
 			count: 1
 			path: app/Utils/SubmissionUtils.php
 
@@ -13456,6 +13461,11 @@ parameters:
 			count: 2
 			path: app/cdash/include/common.php
 
+		-
+			message: "#^Dynamic call to static method Illuminate\\\\Filesystem\\\\FilesystemAdapter\\:\\:path\\(\\)\\.$#"
+			count: 2
+			path: app/cdash/include/common.php
+
 		-
 			message: "#^Function DeleteDirectory\\(\\) throws checked exception UnexpectedValueException but it's missing from the PHPDoc @throws tag\\.$#"
 			count: 1
@@ -13977,26 +13987,6 @@ parameters:
 			count: 1
 			path: app/cdash/include/ctestparser.php
 
-		-
-			message: "#^Function parse_put_submission\\(\\) has parameter \\$expected_md5 with no type specified\\.$#"
-			count: 1
-			path: app/cdash/include/ctestparser.php
-
-		-
-			message: "#^Function parse_put_submission\\(\\) has parameter \\$filehandler with no type specified\\.$#"
-			count: 1
-			path: app/cdash/include/ctestparser.php
-
-		-
-			message: "#^Function parse_put_submission\\(\\) has parameter \\$projectid with no type specified\\.$#"
-			count: 1
-			path: app/cdash/include/ctestparser.php
-
-		-
-			message: "#^Function parse_put_submission\\(\\) throws checked exception CDashParseException but it's missing from the PHPDoc @throws tag\\.$#"
-			count: 2
-			path: app/cdash/include/ctestparser.php
-
 		-
 			message: "#^Loose comparison via \"\\!\\=\" is not allowed\\.$#"
 			count: 2
@@ -14007,11 +13997,6 @@ parameters:
 			count: 1
 			path: app/cdash/include/ctestparser.php
 
-		-
-			message: "#^Offset 'uri' might not exist on array\\{timed_out\\: bool, blocked\\: bool, eof\\: bool, unread_bytes\\: int, stream_type\\: string, wrapper_type\\: string, wrapper_data\\: mixed, mode\\: string, \\.\\.\\.\\}\\.$#"
-			count: 1
-			path: app/cdash/include/ctestparser.php
-
 		-
 			message: "#^Parameter \\#2 \\$data of function xml_parse expects string, string\\|false given\\.$#"
 			count: 2
@@ -22669,7 +22654,7 @@ parameters:
 			path: app/cdash/tests/test_donehandler.php
 
 		-
-			message: "#^Parameter \\#1 \\$haystack of function str_contains expects string, string\\|false given\\.$#"
+			message: "#^Parameter \\#1 \\$haystack of function str_contains expects string, string\\|null given\\.$#"
 			count: 1
 			path: app/cdash/tests/test_donehandler.php
 
@@ -23413,11 +23398,6 @@ parameters:
 			count: 1
 			path: app/cdash/tests/test_extracttar.php
 
-		-
-			message: "#^Parameter \\#1 \\$mystring of method KWWebTestCase\\:\\:findString\\(\\) expects string, string\\|false given\\.$#"
-			count: 2
-			path: app/cdash/tests/test_extracttar.php
-
 		-
 			message: "#^Argument of an invalid type mixed supplied for foreach, only iterables are supported\\.$#"
 			count: 1
@@ -28808,11 +28788,6 @@ parameters:
 			count: 1
 			path: app/cdash/xml_handlers/BazelJSON_handler.php
 
-		-
-			message: "#^Only booleans are allowed in a negated boolean, resource\\|false given\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/BazelJSON_handler.php
-
 		-
 			message: "#^Only booleans are allowed in an if condition, int\\|false given\\.$#"
 			count: 1
@@ -28978,11 +28953,6 @@ parameters:
 			count: 1
 			path: app/cdash/xml_handlers/BuildPropertiesJSON_handler.php
 
-		-
-			message: "#^Parameter \\#1 \\$json of function json_decode expects string, string\\|false given\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/BuildPropertiesJSON_handler.php
-
 		-
 			message: "#^Property CDash\\\\Model\\\\BuildProperties\\:\\:\\$Properties \\(array\\) does not accept mixed\\.$#"
 			count: 1
@@ -29028,16 +28998,6 @@ parameters:
 			count: 3
 			path: app/cdash/xml_handlers/GcovTar_handler.php
 
-		-
-			message: "#^Method GcovTarHandler\\:\\:Parse\\(\\) has no return type specified\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/GcovTar_handler.php
-
-		-
-			message: "#^Method GcovTarHandler\\:\\:Parse\\(\\) has parameter \\$filename with no type specified\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/GcovTar_handler.php
-
 		-
 			message: "#^Method GcovTarHandler\\:\\:Parse\\(\\) throws checked exception UnexpectedValueException but it's missing from the PHPDoc @throws tag\\.$#"
 			count: 2
@@ -29218,16 +29178,6 @@ parameters:
 			count: 2
 			path: app/cdash/xml_handlers/JSCoverTar_handler.php
 
-		-
-			message: "#^Method JSCoverTarHandler\\:\\:Parse\\(\\) has no return type specified\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/JSCoverTar_handler.php
-
-		-
-			message: "#^Method JSCoverTarHandler\\:\\:Parse\\(\\) has parameter \\$filename with no type specified\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/JSCoverTar_handler.php
-
 		-
 			message: "#^Method JSCoverTarHandler\\:\\:Parse\\(\\) throws checked exception UnexpectedValueException but it's missing from the PHPDoc @throws tag\\.$#"
 			count: 1
@@ -29293,16 +29243,6 @@ parameters:
 			count: 2
 			path: app/cdash/xml_handlers/JavaJSONTar_handler.php
 
-		-
-			message: "#^Method JavaJSONTarHandler\\:\\:Parse\\(\\) has no return type specified\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/JavaJSONTar_handler.php
-
-		-
-			message: "#^Method JavaJSONTarHandler\\:\\:Parse\\(\\) has parameter \\$filename with no type specified\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/JavaJSONTar_handler.php
-
 		-
 			message: "#^Method JavaJSONTarHandler\\:\\:Parse\\(\\) throws checked exception UnexpectedValueException but it's missing from the PHPDoc @throws tag\\.$#"
 			count: 1
@@ -29428,16 +29368,6 @@ parameters:
 			count: 6
 			path: app/cdash/xml_handlers/OpenCoverTar_handler.php
 
-		-
-			message: "#^Method OpenCoverTarHandler\\:\\:Parse\\(\\) has no return type specified\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/OpenCoverTar_handler.php
-
-		-
-			message: "#^Method OpenCoverTarHandler\\:\\:Parse\\(\\) has parameter \\$filename with no type specified\\.$#"
-			count: 1
-			path: app/cdash/xml_handlers/OpenCoverTar_handler.php
-
 		-
 			message: "#^Method OpenCoverTarHandler\\:\\:Parse\\(\\) throws checked exception UnexpectedValueException but it's missing from the PHPDoc @throws tag\\.$#"
 			count: 1
diff --git a/tests/Feature/RemoteWorkers.php b/tests/Feature/RemoteWorkers.php
index 9fe67d4ae4..32b737190d 100644
--- a/tests/Feature/RemoteWorkers.php
+++ b/tests/Feature/RemoteWorkers.php
@@ -17,6 +17,7 @@ protected function setUp(): void
         URL::forceRootUrl('http://localhost');
         Config::set('cdash.remote_workers', true);
         Config::set('cdash.backup_timeframe', 0);
+        Config::set('filesystem.default', 'local');
     }
 
     public function testRemoteWorkerAPIAccess(): void