From 2e0e211b267a2369a48c99081608100d25ef0350 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sybren=20A=2E=20St=C3=BCvel?= <sybren@blender.org>
Date: Mon, 30 Sep 2024 11:25:46 +0200
Subject: [PATCH] Fix #104338: Error performing BAT pack

Use RFC 2047 (aka MIME encoding) to send the original filename when
uploading a file to the Shaman server.

HTTP headers should be ASCII-only, and some systems use Latin-1 as
fallback. That's not suitable in general, though, because almost all
characters fall outside the Latin-1 range.
---
 CHANGELOG.md                        |  1 +
 addon/flamenco/bat/shaman.py        | 17 ++++++++++++++++-
 internal/manager/api_impl/shaman.go | 17 ++++++++++++++++-
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 558fac05..4af90e9d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ bugs in actually-released versions.
 - Security updates of dependencies:
   - [GO-2024-3106: Stack exhaustion in Decoder.Decode in encoding/gob](https://pkg.go.dev/vuln/GO-2024-3106)
 - Fix bug where database foreign key constraints could be deactivated ([#104305](https://projects.blender.org/studio/flamenco/issues/104305)).
+- Fix bug when submitting a file with a non-ASCII name via Shaman ([#104338](https://projects.blender.org/studio/flamenco/issues/104338)).
 
 ## 3.5 - released 2024-04-16
 
diff --git a/addon/flamenco/bat/shaman.py b/addon/flamenco/bat/shaman.py
index 4dd4c319..9da2304b 100644
--- a/addon/flamenco/bat/shaman.py
+++ b/addon/flamenco/bat/shaman.py
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 """BAT interface for sending files to the Manager via the Shaman API."""
 
+import email.header
 import logging
 import random
 import platform
@@ -366,6 +367,7 @@ class Transferrer(submodules.transfer.FileTransferer):  # type: ignore
             )
 
             local_filepath = self._rel_to_local_path[file_spec.path]
+            filename_header = _encode_original_filename_header(file_spec.path)
             try:
                 with local_filepath.open("rb") as file_reader:
                     self.shaman_api.shaman_file_store(
@@ -373,7 +375,7 @@ class Transferrer(submodules.transfer.FileTransferer):  # type: ignore
                         filesize=file_spec.size,
                         body=file_reader,
                         x_shaman_can_defer_upload=can_defer,
-                        x_shaman_original_filename=file_spec.path,
+                        x_shaman_original_filename=filename_header,
                     )
             except ApiException as ex:
                 if ex.status == 425:
@@ -527,3 +529,16 @@ def _root_path_strip(path: PurePath) -> PurePosixPath:
     if path.is_absolute():
         return PurePosixPath(*path.parts[1:])
     return PurePosixPath(path)
+
+
+def _encode_original_filename_header(filename: str) -> str:
+    """Encode the 'original filename' as valid HTTP Header.
+
+    See the specs for the X-Shaman-Original-Filename header in the OpenAPI
+    operation `shamanFileStore`, defined in flamenco-openapi.yaml.
+    """
+
+    # This is a no-op when the filename is already in ASCII.
+    fake_header = email.header.Header()
+    fake_header.append(filename, charset="utf-8")
+    return fake_header.encode()
diff --git a/internal/manager/api_impl/shaman.go b/internal/manager/api_impl/shaman.go
index 0596c203..91069118 100644
--- a/internal/manager/api_impl/shaman.go
+++ b/internal/manager/api_impl/shaman.go
@@ -3,6 +3,7 @@ package api_impl
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 import (
+	"mime"
 	"net/http"
 
 	"github.com/labstack/echo/v4"
@@ -110,8 +111,22 @@ func (f *Flamenco) ShamanFileStore(e echo.Context, checksum string, filesize int
 		canDefer = *params.XShamanCanDeferUpload
 		logCtx = logCtx.Bool("canDefer", canDefer)
 	}
+
 	if params.XShamanOriginalFilename != nil {
-		origFilename = *params.XShamanOriginalFilename
+		rawHeadervalue := *params.XShamanOriginalFilename
+		decoder := mime.WordDecoder{}
+
+		var err error // origFilename has to be used from the outer scope.
+		origFilename, err = decoder.DecodeHeader(rawHeadervalue)
+		if err != nil {
+			logger := logCtx.Logger()
+			logger.Error().
+				Str("headerValue", rawHeadervalue).
+				Err(err).
+				Msg("shaman: received invalid X-Shaman-Original-Filename header")
+			return sendAPIError(e, http.StatusBadRequest, "invalid X-Shaman-Original-Filename header: %q", rawHeadervalue)
+		}
+
 		logCtx = logCtx.Str("originalFilename", origFilename)
 	}
 	logger := logCtx.Logger()