Fix Issue6791 - Limit the HTTP header readline with _MAXLENGTH. Patch by Antoine Pitrou
diff --git a/Lib/http/client.py b/Lib/http/client.py
index 7c97560..8ea75ce 100644
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -203,6 +203,9 @@
# maximal amount of data to read at one time in _safe_read
MAXAMOUNT = 1048576
+# maximal line length when calling readline().
+_MAXLINE = 65536
+
class HTTPMessage(email.message.Message):
# XXX The only usage of this method is in
# http.server.CGIHTTPRequestHandler. Maybe move the code there so
@@ -245,7 +248,9 @@
"""
headers = []
while True:
- line = fp.readline()
+ line = fp.readline(_MAXLINE + 1)
+ if len(line) > _MAXLINE:
+ raise LineTooLong("header line")
headers.append(line)
if line in (b'\r\n', b'\n', b''):
break
@@ -299,7 +304,9 @@
self.will_close = _UNKNOWN # conn will close at end of response
def _read_status(self):
- line = str(self.fp.readline(), "iso-8859-1")
+ line = str(self.fp.readline(_MAXLINE + 1), "iso-8859-1")
+ if len(line) > _MAXLINE:
+ raise LineTooLong("status line")
if self.debuglevel > 0:
print("reply:", repr(line))
if not line:
@@ -340,7 +347,10 @@
break
# skip the header from the 100 response
while True:
- skip = self.fp.readline().strip()
+ skip = self.fp.readline(_MAXLINE + 1)
+ if len(skip) > _MAXLINE:
+ raise LineTooLong("header line")
+ skip = skip.strip()
if not skip:
break
if self.debuglevel > 0:
@@ -508,7 +518,9 @@
value = []
while True:
if chunk_left is None:
- line = self.fp.readline()
+ line = self.fp.readline(_MAXLINE + 1)
+ if len(line) > _MAXLINE:
+ raise LineTooLong("chunk size")
i = line.find(b";")
if i >= 0:
line = line[:i] # strip chunk-extensions
@@ -543,7 +555,9 @@
# read and discard trailer up to the CRLF terminator
### note: we shouldn't have any trailers!
while True:
- line = self.fp.readline()
+ line = self.fp.readline(_MAXLINE + 1)
+ if len(line) > _MAXLINE:
+ raise LineTooLong("trailer line")
if not line:
# a vanishingly small number of sites EOF without
# sending the trailer
@@ -692,7 +706,9 @@
raise socket.error("Tunnel connection failed: %d %s" % (code,
message.strip()))
while True:
- line = response.fp.readline()
+ line = response.fp.readline(_MAXLINE + 1)
+ if len(line) > _MAXLINE:
+ raise LineTooLong("header line")
if line == b'\r\n':
break
@@ -1137,5 +1153,10 @@
self.args = line,
self.line = line
+class LineTooLong(HTTPException):
+ def __init__(self, line_type):
+ HTTPException.__init__(self, "got more than %d bytes when reading %s"
+ % (_MAXLINE, line_type))
+
# for backwards compatibility
error = HTTPException