`IPV4_RE` includes a `.`, and the `.find(".") == -1` included here is already testing to make sure there's no dot, so this part of the expression is tautological. Instead use more modern `in` syntax to make it clear what the check is doing here. The simplified implementation more clearly matches the wording in RFC 2965.
Co-authored-by: hauntsaninja <hauntsaninja@gmail.com>
If you had a directory called index.html or index.htm within a directory, it would cause http.server to return a 404 Not Found error instead of the directory listing. This came about due to not checking that the index was a regular file.
I have also added a test case for this situation.
Automerge-Triggered-By: GH:merwok
Also \ escape \s in the http.server BaseHTTPRequestHandler.log_message so
that it is technically possible to parse the line and reconstruct what the
original data was. Without this a \xHH is ambiguious as to if it is a hex
replacement we put in or the characters r"\x" came through in the original
request line.
Replace control characters in http.server.BaseHTTPRequestHandler.log_message with an escaped \xHH sequence to avoid causing problems for the terminal the output is printed to.
Remove the keyfile, certfile and check_hostname parameters,
deprecated since Python 3.6, in modules: ftplib, http.client,
imaplib, poplib and smtplib. Use the context parameter (ssl_context
in imaplib) instead.
Parameters following the removed parameters become keyword-only
parameters.
ftplib: Remove the FTP_TLS.ssl_version class attribute: use the
context parameter instead.
The urllib.request no longer uses the deprecated check_hostname
parameter of the http.client module.
Add private http.client._create_https_context() helper to http.client,
used by urllib.request.
Remove the now redundant check on check_hostname and verify_mode in
http.client: the SSLContext.check_hostname setter already implements
the check.
* Add an index_pages default list to SimpleHTTPRequestHandler and an
optional constructor parameter that allows the default indexes pages
list to be overridden. This makes it easy to set a new index page name
without having to override send_head.
Fix an open redirection vulnerability in the `http.server` module when
an URI path starts with `//` that could produce a 301 Location header
with a misleading target. Vulnerability discovered, and logic fix
proposed, by Hamza Avvan (@hamzaavvan).
Test and comments authored by Gregory P. Smith [Google].
Note: This change is not effective on Microsoft Windows.
Cookies can store sensitive information and should therefore be protected
against unauthorized third parties. This is also described in issue #79096.
The filesystem permissions are currently set to 644, everyone can read the
file. This commit changes the permissions to 600, only the creater of the file
can read and modify it. This improves security, because it reduces the attack
surface. Now the attacker needs control of the user that created the cookie or
a ways to circumvent the filesystems permissions.
This change is backwards incompatible. Systems that rely on world-readable
cookies will breake. However, one could argue that those are misconfigured in
the first place.
* Set content-length for simple http server 301s
When http.server.SimpleHTTPRequestHandler sends a 301 (Moved
Permanently) due to a missing file, it does not set a Content-Length
of 0. Unfortunately, certain clients can be left waiting for the
connection to be closed in this circumstance, even though no body
will be sent. At time of writing, both curl and Firefox demonstrate
this behavior.
* Test Content-Length on simple http server redirect
When serving a redirect, the SimpleHTTPRequestHandler will now send
`Content-Length: 0`. Several tests for http.server already cover
various behaviors and checks including redirection. This change only
adds one check for the expected Content-Length on the simplest case
for a redirect.
* Add news entry for SimpleHTTPRequestHandler fix
* Clarify the specific kind of 301
Co-authored-by: Senthil Kumaran <skumaran@gatech.edu>
Fixes http.client potential denial of service where it could get stuck reading lines from a malicious server after a 100 Continue response.
Co-authored-by: Gregory P. Smith <greg@krypto.org>
add:
* `_simple_enum` decorator to transform a normal class into an enum
* `_test_simple_enum` function to compare
* `_old_convert_` to enable checking `_convert_` generated enums
`_simple_enum` takes a normal class and converts it into an enum:
@simple_enum(Enum)
class Color:
RED = 1
GREEN = 2
BLUE = 3
`_old_convert_` works much like` _convert_` does, using the original logic:
# in a test file
import socket, enum
CheckedAddressFamily = enum._old_convert_(
enum.IntEnum, 'AddressFamily', 'socket',
lambda C: C.isupper() and C.startswith('AF_'),
source=_socket,
)
`_test_simple_enum` takes a traditional enum and a simple enum and
compares the two:
# in the REPL or the same module as Color
class CheckedColor(Enum):
RED = 1
GREEN = 2
BLUE = 3
_test_simple_enum(CheckedColor, Color)
_test_simple_enum(CheckedAddressFamily, socket.AddressFamily)
Any important differences will raise a TypeError
add:
_simple_enum decorator to transform a normal class into an enum
_test_simple_enum function to compare
_old_convert_ to enable checking _convert_ generated enums
_simple_enum takes a normal class and converts it into an enum:
@simple_enum(Enum)
class Color:
RED = 1
GREEN = 2
BLUE = 3
_old_convert_ works much like _convert_ does, using the original logic:
# in a test file
import socket, enum
CheckedAddressFamily = enum._old_convert_(
enum.IntEnum, 'AddressFamily', 'socket',
lambda C: C.isupper() and C.startswith('AF_'),
source=_socket,
)
test_simple_enum takes a traditional enum and a simple enum and
compares the two:
# in the REPL or the same module as Color
class CheckedColor(Enum):
RED = 1
GREEN = 2
BLUE = 3
_test_simple_enum(CheckedColor, Color)
_test_simple_enum(CheckedAddressFamily, socket.AddressFamily)
Any important differences will raise a TypeError
We now buffer the CONNECT request + tunnel HTTP headers into a single
send call. This prevents the OS from generating multiple network
packets for connection setup when not necessary, improving efficiency.
I've done the implementation for both non-chunked and chunked reads. I haven't benchmarked chunked reads because I don't currently have a convenient way to generate a high-bandwidth chunked stream, but I don't see any reason that it shouldn't enjoy the same benefits that the non-chunked case does. I've used the benchmark attached to the bpo bug to verify that performance now matches the unsized read case.
Automerge-Triggered-By: @methane
CGIHTTPRequestHandler of http.server now logs the CGI script exit
code, rather than the CGI script exit status of os.waitpid().
For example, if the script is killed by signal 11, it now logs:
"CGI script exit code -11."
The regex http.cookiejar.LOOSE_HTTP_DATE_RE was vulnerable to regular
expression denial of service (REDoS).
LOOSE_HTTP_DATE_RE.match is called when using http.cookiejar.CookieJar
to parse Set-Cookie headers returned by a server.
Processing a response from a malicious HTTP server can lead to extreme
CPU usage and execution will be blocked for a long time.
The regex contained multiple overlapping \s* capture groups.
Ignoring the ?-optional capture groups the regex could be simplified to
\d+-\w+-\d+(\s*\s*\s*)$
Therefore, a long sequence of spaces can trigger bad performance.
Matching a malicious string such as
LOOSE_HTTP_DATE_RE.match("1-c-1" + (" " * 2000) + "!")
caused catastrophic backtracking.
The fix removes ambiguity about which \s* should match a particular
space.
You can create a malicious server which responds with Set-Cookie headers
to attack all python programs which access it e.g.
from http.server import BaseHTTPRequestHandler, HTTPServer
def make_set_cookie_value(n_spaces):
spaces = " " * n_spaces
expiry = f"1-c-1{spaces}!"
return f"b;Expires={expiry}"
class Handler(BaseHTTPRequestHandler):
def do_GET(self):
self.log_request(204)
self.send_response_only(204) # Don't bother sending Server and Date
n_spaces = (
int(self.path[1:]) # Can GET e.g. /100 to test shorter sequences
if len(self.path) > 1 else
65506 # Max header line length 65536
)
value = make_set_cookie_value(n_spaces)
for i in range(99): # Not necessary, but we can have up to 100 header lines
self.send_header("Set-Cookie", value)
self.end_headers()
if __name__ == "__main__":
HTTPServer(("", 44020), Handler).serve_forever()
This server returns 99 Set-Cookie headers. Each has 65506 spaces.
Extracting the cookies will pretty much never complete.
Vulnerable client using the example at the bottom of
https://docs.python.org/3/library/http.cookiejar.html :
import http.cookiejar, urllib.request
cj = http.cookiejar.CookieJar()
opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))
r = opener.open("http://localhost:44020/")
The popular requests library was also vulnerable without any additional
options (as it uses http.cookiejar by default):
import requests
requests.get("http://localhost:44020/")
* Regression test for http.cookiejar REDoS
If we regress, this test will take a very long time.
* Improve performance of http.cookiejar.ISO_DATE_RE
A string like
"444444" + (" " * 2000) + "A"
could cause poor performance due to the 2 overlapping \s* groups,
although this is not as serious as the REDoS in LOOSE_HTTP_DATE_RE was.
Ethan Furman
Glyph
James Frost
Nikita Sobolev
Gregory P. Smith
Nick Drozd
Victor Stinner
Boris Verkhovskiy
Alexandru Mărășteanu
Myron Walker
Pascal Wittmann
cibofo
Géry Ogam
Iman Kermani
Nick
Dong-hee Na
180909
rtobar
Binbin
Stephen Rosen
Gen Xu
Saiyang Gou
Fernando Toledo
Senthil Kumaran
Christian Heimes
Jacob Neil Taylor
AMIR
Bruce Merry
Batuhan Taşkaya
Ross
Ashwin Ramaswami
An Long
Jason R. Coombs
bcaller