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# HG changeset patch
# User Benjamin Peterson <benjamin@python.org>
# Date 1417828515 18000
# Node ID d50096708b2d701937e78f525446d729fc28db88
# Parent 923aac88a3cc76a95d5a04d9d3ece245147a8064
add a default limit for the amount of data xmlrpclib.gzip_decode will return (closes #16043)
diff --git a/Lib/test/test_xmlrpc.py b/Lib/test/test_xmlrpc.py
--- a/Lib/test/test_xmlrpc.py
+++ b/Lib/test/test_xmlrpc.py
@@ -737,7 +737,7 @@ class GzipServerTestCase(BaseServerTestC
with cm:
p.pow(6, 8)
- def test_gsip_response(self):
+ def test_gzip_response(self):
t = self.Transport()
p = xmlrpclib.ServerProxy(URL, transport=t)
old = self.requestHandler.encode_threshold
@@ -750,6 +750,23 @@ class GzipServerTestCase(BaseServerTestC
self.requestHandler.encode_threshold = old
self.assertTrue(a>b)
+ def test_gzip_decode_limit(self):
+ max_gzip_decode = 20 * 1024 * 1024
+ data = '\0' * max_gzip_decode
+ encoded = xmlrpclib.gzip_encode(data)
+ decoded = xmlrpclib.gzip_decode(encoded)
+ self.assertEqual(len(decoded), max_gzip_decode)
+
+ data = '\0' * (max_gzip_decode + 1)
+ encoded = xmlrpclib.gzip_encode(data)
+
+ with self.assertRaisesRegexp(ValueError,
+ "max gzipped payload length exceeded"):
+ xmlrpclib.gzip_decode(encoded)
+
+ xmlrpclib.gzip_decode(encoded, max_decode=-1)
+
+
#Test special attributes of the ServerProxy object
class ServerProxyTestCase(unittest.TestCase):
def setUp(self):
diff --git a/Lib/xmlrpclib.py b/Lib/xmlrpclib.py
--- a/Lib/xmlrpclib.py
+++ b/Lib/xmlrpclib.py
@@ -49,6 +49,7 @@
# 2003-07-12 gp Correct marshalling of Faults
# 2003-10-31 mvl Add multicall support
# 2004-08-20 mvl Bump minimum supported Python version to 2.1
+# 2014-12-02 ch/doko Add workaround for gzip bomb vulnerability
#
# Copyright (c) 1999-2002 by Secret Labs AB.
# Copyright (c) 1999-2002 by Fredrik Lundh.
@@ -1165,10 +1166,13 @@ def gzip_encode(data):
# in the HTTP header, as described in RFC 1952
#
# @param data The encoded data
+# @keyparam max_decode Maximum bytes to decode (20MB default), use negative
+# values for unlimited decoding
# @return the unencoded data
# @raises ValueError if data is not correctly coded.
+# @raises ValueError if max gzipped payload length exceeded
-def gzip_decode(data):
+def gzip_decode(data, max_decode=20971520):
"""gzip encoded data -> unencoded data
Decode data using the gzip content encoding as described in RFC 1952
@@ -1178,11 +1182,16 @@ def gzip_decode(data):
f = StringIO.StringIO(data)
gzf = gzip.GzipFile(mode="rb", fileobj=f)
try:
- decoded = gzf.read()
+ if max_decode < 0: # no limit
+ decoded = gzf.read()
+ else:
+ decoded = gzf.read(max_decode + 1)
except IOError:
raise ValueError("invalid data")
f.close()
gzf.close()
+ if max_decode >= 0 and len(decoded) > max_decode:
+ raise ValueError("max gzipped payload length exceeded")
return decoded
##