diff --git a/synapse/http/proxy.py b/synapse/http/proxy.py
index 97aa429e7d..5cd990b0d0 100644
--- a/synapse/http/proxy.py
+++ b/synapse/http/proxy.py
@@ -51,25 +51,17 @@ logger = logging.getLogger(__name__)
# "Hop-by-hop" headers (as opposed to "end-to-end" headers) as defined by RFC2616
# section 13.5.1 and referenced in RFC9110 section 7.6.1. These are meant to only be
# consumed by the immediate recipient and not be forwarded on.
-HOP_BY_HOP_HEADERS = {
- "Connection",
- "Keep-Alive",
- "Proxy-Authenticate",
- "Proxy-Authorization",
- "TE",
- "Trailers",
- "Transfer-Encoding",
- "Upgrade",
+HOP_BY_HOP_HEADERS_LOWERCASE = {
+ "connection",
+ "keep-alive",
+ "proxy-authenticate",
+ "proxy-authorization",
+ "te",
+ "trailers",
+ "transfer-encoding",
+ "upgrade",
}
-
-if hasattr(Headers, "_canonicalNameCaps"):
- # Twisted < 24.7.0rc1
- _canonicalHeaderName = Headers()._canonicalNameCaps # type: ignore[attr-defined]
-else:
- # Twisted >= 24.7.0rc1
- # But note that `_encodeName` still exists on prior versions,
- # it just encodes differently
- _canonicalHeaderName = Headers()._encodeName
+assert all(header.lower() == header for header in HOP_BY_HOP_HEADERS_LOWERCASE)
def parse_connection_header_value(
@@ -92,12 +84,12 @@ def parse_connection_header_value(
Returns:
The set of header names that should not be copied over from the remote response.
- The keys are capitalized in canonical capitalization.
+ The keys are lowercased.
"""
extra_headers_to_remove: Set[str] = set()
if connection_header_value:
extra_headers_to_remove = {
- _canonicalHeaderName(connection_option.strip()).decode("ascii")
+ connection_option.decode("ascii").strip().lower()
for connection_option in connection_header_value.split(b",")
}
@@ -194,7 +186,7 @@ class ProxyResource(_AsyncResource):
# The `Connection` header also defines which headers should not be copied over.
connection_header = response_headers.getRawHeaders(b"connection")
- extra_headers_to_remove = parse_connection_header_value(
+ extra_headers_to_remove_lowercase = parse_connection_header_value(
connection_header[0] if connection_header else None
)
@@ -202,10 +194,10 @@ class ProxyResource(_AsyncResource):
for k, v in response_headers.getAllRawHeaders():
# Do not copy over any hop-by-hop headers. These are meant to only be
# consumed by the immediate recipient and not be forwarded on.
- header_key = k.decode("ascii")
+ header_key_lowercase = k.decode("ascii").lower()
if (
- header_key in HOP_BY_HOP_HEADERS
- or header_key in extra_headers_to_remove
+ header_key_lowercase in HOP_BY_HOP_HEADERS_LOWERCASE
+ or header_key_lowercase in extra_headers_to_remove_lowercase
):
continue
|
