diff --git a/synapse/rest/media/v1/_base.py b/synapse/rest/media/v1/_base.py
index fece1ef0b8..953d89bd82 100644
--- a/synapse/rest/media/v1/_base.py
+++ b/synapse/rest/media/v1/_base.py
@@ -100,10 +100,29 @@ def add_file_headers(request, media_type, file_size, upload_name):
request.setHeader(b"Content-Type", media_type.encode("UTF-8"))
if upload_name:
- if is_ascii(upload_name):
- disposition = "inline; filename=%s" % (_quote(upload_name),)
+ # RFC6266 section 4.1 [1] defines both `filename` and `filename*`.
+ #
+ # `filename` is defined to be a `value`, which is defined by RFC2616
+ # section 3.6 [2] to be a `token` or a `quoted-string`, where a `token`
+ # is (essentially) a single US-ASCII word, and a `quoted-string` is a
+ # US-ASCII string surrounded by double-quotes, using backslash as an
+ # escape charater. Note that %-encoding is *not* permitted.
+ #
+ # `filename*` is defined to be an `ext-value`, which is defined in
+ # RFC5987 section 3.2.1 [3] to be `charset "'" [ language ] "'" value-chars`,
+ # where `value-chars` is essentially a %-encoded string in the given charset.
+ #
+ # [1]: https://tools.ietf.org/html/rfc6266#section-4.1
+ # [2]: https://tools.ietf.org/html/rfc2616#section-3.6
+ # [3]: https://tools.ietf.org/html/rfc5987#section-3.2.1
+
+ # We avoid the quoted-string version of `filename`, because (a) synapse didn't
+ # correctly interpret those as of 0.99.2 and (b) they are a bit of a pain and we
+ # may as well just do the filename* version.
+ if _can_encode_filename_as_token(upload_name):
+ disposition = 'inline; filename=%s' % (upload_name, )
else:
- disposition = "inline; filename*=utf-8''%s" % (_quote(upload_name),)
+ disposition = "inline; filename*=utf-8''%s" % (_quote(upload_name), )
request.setHeader(b"Content-Disposition", disposition.encode('ascii'))
@@ -116,6 +135,35 @@ def add_file_headers(request, media_type, file_size, upload_name):
request.setHeader(b"Content-Length", b"%d" % (file_size,))
+# separators as defined in RFC2616. SP and HT are handled separately.
+# see _can_encode_filename_as_token.
+_FILENAME_SEPARATOR_CHARS = set((
+ "(", ")", "<", ">", "@", ",", ";", ":", "\\", '"',
+ "/", "[", "]", "?", "=", "{", "}",
+))
+
+
+def _can_encode_filename_as_token(x):
+ for c in x:
+ # from RFC2616:
+ #
+ # token = 1*<any CHAR except CTLs or separators>
+ #
+ # separators = "(" | ")" | "<" | ">" | "@"
+ # | "," | ";" | ":" | "\" | <">
+ # | "/" | "[" | "]" | "?" | "="
+ # | "{" | "}" | SP | HT
+ #
+ # CHAR = <any US-ASCII character (octets 0 - 127)>
+ #
+ # CTL = <any US-ASCII control character
+ # (octets 0 - 31) and DEL (127)>
+ #
+ if ord(c) >= 127 or ord(c) <= 32 or c in _FILENAME_SEPARATOR_CHARS:
+ return False
+ return True
+
+
@defer.inlineCallbacks
def respond_with_responder(request, responder, media_type, file_size, upload_name=None):
"""Responds to the request with given responder. If responder is None then
|