win32: work around a WinError problem handling HRESULT types
I ran into this ctypes bug while working with the Crypto API. While this could
be an issue with any Win32 API in theory, the handful of things that we call are
older functions that are unlikely to return COM errors, so I didn't retrofit
this everywhere.
# 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 uuid
from .. import (
encoding,
pycompat,
util,
)
httpserver = util.httpserver
HTTP_OK = 200
HTTP_NOT_MODIFIED = 304
HTTP_BAD_REQUEST = 400
HTTP_UNAUTHORIZED = 401
HTTP_FORBIDDEN = 403
HTTP_NOT_FOUND = 404
HTTP_METHOD_NOT_ALLOWED = 405
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 == ['*'] 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.env.get('REMOTE_USER')
deny_read = hgweb.configlist('web', 'deny_read')
if deny_read and (not user or ismember(hgweb.repo.ui, user, deny_read)):
raise ErrorResponse(HTTP_UNAUTHORIZED, 'read not authorized')
allow_read = hgweb.configlist('web', 'allow_read')
if allow_read and (not ismember(hgweb.repo.ui, user, allow_read)):
raise ErrorResponse(HTTP_UNAUTHORIZED, 'read not authorized')
if op == 'pull' and not hgweb.allowpull:
raise ErrorResponse(HTTP_UNAUTHORIZED, 'pull not authorized')
elif op == 'pull' or op is None: # op is None for interface requests
return
# enforce that you can only push using POST requests
if req.env['REQUEST_METHOD'] != 'POST':
msg = 'push requires POST request'
raise ErrorResponse(HTTP_METHOD_NOT_ALLOWED, msg)
# require ssl by default for pushing, auth info cannot be sniffed
# and replayed
scheme = req.env.get('wsgi.url_scheme')
if hgweb.configbool('web', 'push_ssl', True) and scheme != 'https':
raise ErrorResponse(HTTP_FORBIDDEN, 'ssl required')
deny = hgweb.configlist('web', 'deny_push')
if deny and (not user or ismember(hgweb.repo.ui, user, deny)):
raise ErrorResponse(HTTP_UNAUTHORIZED, 'push not authorized')
allow = hgweb.configlist('web', 'allow_push')
if not (allow and ismember(hgweb.repo.ui, user, allow)):
raise ErrorResponse(HTTP_UNAUTHORIZED, '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 or push. 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, message)
self.code = code
if headers is None:
headers = []
self.headers = headers
class continuereader(object):
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('HTTP/1.1 100 Continue\r\n\r\n')
return self.f.read(amt)
def __getattr__(self, attr):
if attr in ('close', 'readline', 'readlines', '__iter__'):
return getattr(self.f, attr)
raise AttributeError
def _statusmessage(code):
responses = httpserver.basehttprequesthandler.responses
return responses.get(code, ('Error', 'Unknown error'))[0]
def statusmessage(code, message=None):
return '%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, "00changelog.i").st_mtime
def ispathsafe(path):
"""Determine if a path is safe to use for filesystem access."""
parts = path.split('/')
for part in parts:
if (part in ('', os.curdir, os.pardir) or
pycompat.ossep in part or
pycompat.osaltsep is not None and pycompat.osaltsep in part):
return False
return True
def staticfile(directory, fname, req):
"""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
fpath = os.path.join(*fname.split('/'))
if isinstance(directory, str):
directory = [directory]
for d in directory:
path = os.path.join(d, fpath)
if os.path.exists(path):
break
try:
os.stat(path)
ct = mimetypes.guess_type(path)[0] or "text/plain"
with open(path, 'rb') as fh:
data = fh.read()
req.respond(HTTP_OK, ct, body=data)
except TypeError:
raise ErrorResponse(HTTP_SERVER_ERROR, 'illegal filename')
except OSError as err:
if err.errno == errno.ENOENT:
raise ErrorResponse(HTTP_NOT_FOUND)
else:
raise ErrorResponse(HTTP_SERVER_ERROR, err.strerror)
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("web", "contact") or
config("ui", "username") or
encoding.environ.get("EMAIL") or "")
def caching(web, req):
tag = 'W/"%s"' % web.mtime
if req.env.get('HTTP_IF_NONE_MATCH') == tag:
raise ErrorResponse(HTTP_NOT_MODIFIED)
req.headers.append(('ETag', tag))
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.
"""
# Don't allow untrusted CSP setting since it be disable protections
# from a trusted/global source.
csp = ui.config('web', 'csp', untrusted=False)
nonce = None
if csp and '%nonce%' in csp:
nonce = base64.urlsafe_b64encode(uuid.uuid4().bytes).rstrip('=')
csp = csp.replace('%nonce%', nonce)
return csp, nonce