# hgweb/common.py - Utility functions needed by hgweb_mod and hgwebdir_mod
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net>
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import base64
import errno
import mimetypes
import os
import stat
from ..pycompat import (
getattr,
open,
)
from .. import (
encoding,
pycompat,
templater,
util,
)
httpserver = util.httpserver
HTTP_OK = 200
HTTP_CREATED = 201
HTTP_NOT_MODIFIED = 304
HTTP_BAD_REQUEST = 400
HTTP_UNAUTHORIZED = 401
HTTP_FORBIDDEN = 403
HTTP_NOT_FOUND = 404
HTTP_METHOD_NOT_ALLOWED = 405
HTTP_NOT_ACCEPTABLE = 406
HTTP_UNSUPPORTED_MEDIA_TYPE = 415
HTTP_SERVER_ERROR = 500
def ismember(ui, username, userlist):
"""Check if username is a member of userlist.
If userlist has a single '*' member, all users are considered members.
Can be overridden by extensions to provide more complex authorization
schemes.
"""
return userlist == [b'*'] or username in userlist
def checkauthz(hgweb, req, op):
"""Check permission for operation based on request data (including
authentication info). Return if op allowed, else raise an ErrorResponse
exception."""
user = req.remoteuser
deny_read = hgweb.configlist(b'web', b'deny_read')
if deny_read and (not user or ismember(hgweb.repo.ui, user, deny_read)):
raise ErrorResponse(HTTP_UNAUTHORIZED, b'read not authorized')
allow_read = hgweb.configlist(b'web', b'allow_read')
if allow_read and (not ismember(hgweb.repo.ui, user, allow_read)):
raise ErrorResponse(HTTP_UNAUTHORIZED, b'read not authorized')
if op == b'pull' and not hgweb.allowpull:
raise ErrorResponse(HTTP_UNAUTHORIZED, b'pull not authorized')
elif op == b'pull' or op is None: # op is None for interface requests
return
# Allow LFS uploading via PUT requests
if op == b'upload':
if req.method != b'PUT':
msg = b'upload requires PUT request'
raise ErrorResponse(HTTP_METHOD_NOT_ALLOWED, msg)
# enforce that you can only push using POST requests
elif req.method != b'POST':
msg = b'push requires POST request'
raise ErrorResponse(HTTP_METHOD_NOT_ALLOWED, msg)
# require ssl by default for pushing, auth info cannot be sniffed
# and replayed
if hgweb.configbool(b'web', b'push_ssl') and req.urlscheme != b'https':
raise ErrorResponse(HTTP_FORBIDDEN, b'ssl required')
deny = hgweb.configlist(b'web', b'deny_push')
if deny and (not user or ismember(hgweb.repo.ui, user, deny)):
raise ErrorResponse(HTTP_UNAUTHORIZED, b'push not authorized')
allow = hgweb.configlist(b'web', b'allow-push')
if not (allow and ismember(hgweb.repo.ui, user, allow)):
raise ErrorResponse(HTTP_UNAUTHORIZED, b'push not authorized')
# Hooks for hgweb permission checks; extensions can add hooks here.
# Each hook is invoked like this: hook(hgweb, request, operation),
# where operation is either read, pull, push or upload. Hooks should either
# raise an ErrorResponse exception, or just return.
#
# It is possible to do both authentication and authorization through
# this.
permhooks = [checkauthz]
class ErrorResponse(Exception):
def __init__(self, code, message=None, headers=None):
if message is None:
message = _statusmessage(code)
Exception.__init__(self, pycompat.sysstr(message))
self.code = code
if headers is None:
headers = []
self.headers = headers
self.message = message
class continuereader(object):
"""File object wrapper to handle HTTP 100-continue.
This is used by servers so they automatically handle Expect: 100-continue
request headers. On first read of the request body, the 100 Continue
response is sent. This should trigger the client into actually sending
the request body.
"""
def __init__(self, f, write):
self.f = f
self._write = write
self.continued = False
def read(self, amt=-1):
if not self.continued:
self.continued = True
self._write(b'HTTP/1.1 100 Continue\r\n\r\n')
return self.f.read(amt)
def __getattr__(self, attr):
if attr in (b'close', b'readline', b'readlines', b'__iter__'):
return getattr(self.f, attr)
raise AttributeError
def _statusmessage(code):
responses = httpserver.basehttprequesthandler.responses
return pycompat.bytesurl(responses.get(code, ('Error', 'Unknown error'))[0])
def statusmessage(code, message=None):
return b'%d %s' % (code, message or _statusmessage(code))
def get_stat(spath, fn):
"""stat fn if it exists, spath otherwise"""
cl_path = os.path.join(spath, fn)
if os.path.exists(cl_path):
return os.stat(cl_path)
else:
return os.stat(spath)
def get_mtime(spath):
return get_stat(spath, b"00changelog.i")[stat.ST_MTIME]
def ispathsafe(path):
"""Determine if a path is safe to use for filesystem access."""
parts = path.split(b'/')
for part in parts:
if (
part in (b'', pycompat.oscurdir, pycompat.ospardir)
or pycompat.ossep in part
or pycompat.osaltsep is not None
and pycompat.osaltsep in part
):
return False
return True
def staticfile(templatepath, directory, fname, res):
"""return a file inside directory with guessed Content-Type header
fname always uses '/' as directory separator and isn't allowed to
contain unusual path components.
Content-Type is guessed using the mimetypes module.
Return an empty string if fname is illegal or file not found.
"""
if not ispathsafe(fname):
return
if not directory:
tp = templatepath or templater.templatedir()
if tp is not None:
directory = os.path.join(tp, b'static')
fpath = os.path.join(*fname.split(b'/'))
ct = pycompat.sysbytes(
mimetypes.guess_type(pycompat.fsdecode(fpath))[0] or r"text/plain"
)
path = os.path.join(directory, fpath)
try:
os.stat(path)
with open(path, b'rb') as fh:
data = fh.read()
except TypeError:
raise ErrorResponse(HTTP_SERVER_ERROR, b'illegal filename')
except OSError as err:
if err.errno == errno.ENOENT:
raise ErrorResponse(HTTP_NOT_FOUND)
else:
raise ErrorResponse(
HTTP_SERVER_ERROR, encoding.strtolocal(err.strerror)
)
res.headers[b'Content-Type'] = ct
res.setbodybytes(data)
return res
def paritygen(stripecount, offset=0):
"""count parity of horizontal stripes for easier reading"""
if stripecount and offset:
# account for offset, e.g. due to building the list in reverse
count = (stripecount + offset) % stripecount
parity = (stripecount + offset) // stripecount & 1
else:
count = 0
parity = 0
while True:
yield parity
count += 1
if stripecount and count >= stripecount:
parity = 1 - parity
count = 0
def get_contact(config):
"""Return repo contact information or empty string.
web.contact is the primary source, but if that is not set, try
ui.username or $EMAIL as a fallback to display something useful.
"""
return (
config(b"web", b"contact")
or config(b"ui", b"username")
or encoding.environ.get(b"EMAIL")
or b""
)
def cspvalues(ui):
"""Obtain the Content-Security-Policy header and nonce value.
Returns a 2-tuple of the CSP header value and the nonce value.
First value is ``None`` if CSP isn't enabled. Second value is ``None``
if CSP isn't enabled or if the CSP header doesn't need a nonce.
"""
# Without demandimport, "import uuid" could have an immediate side-effect
# running "ldconfig" on Linux trying to find libuuid.
# With Python <= 2.7.12, that "ldconfig" is run via a shell and the shell
# may pollute the terminal with:
#
# shell-init: error retrieving current directory: getcwd: cannot access
# parent directories: No such file or directory
#
# Python >= 2.7.13 has fixed it by running "ldconfig" directly without a
# shell (hg changeset a09ae70f3489).
#
# Moved "import uuid" from here so it's executed after we know we have
# a sane cwd (i.e. after dispatch.py cwd check).
#
# We can move it back once we no longer need Python <= 2.7.12 support.
import uuid
# Don't allow untrusted CSP setting since it be disable protections
# from a trusted/global source.
csp = ui.config(b'web', b'csp', untrusted=False)
nonce = None
if csp and b'%nonce%' in csp:
nonce = base64.urlsafe_b64encode(uuid.uuid4().bytes).rstrip(b'=')
csp = csp.replace(b'%nonce%', nonce)
return csp, nonce