url: add some defensive asserts on expected incoming types

Our type handling is a nightmare here, and we're loading passwords to
do network IO, so we can afford to be potentially-slow but pedantic
here.

Differential Revision: https://phab.mercurial-scm.org/D5734

mercurial/url.py

@@ -1,639 +1,641
 # url.py - HTTP handling for mercurial
 #
 # Copyright 2005, 2006, 2007, 2008 Matt Mackall <[e-mail]>
 # Copyright 2006, 2007 Alexis S. L. Carvalho <[e-mail]>
 # Copyright 2006 Vadim Gelfer <[e-mail]>
 #
 # 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 os
 import socket
 import sys
 
 from .i18n import _
 from . import (
     encoding,
     error,
     httpconnection as httpconnectionmod,
     keepalive,
     pycompat,
     sslutil,
     urllibcompat,
     util,
 )
 from .utils import (
     stringutil,
 )
 
 httplib = util.httplib
 stringio = util.stringio
 urlerr = util.urlerr
 urlreq = util.urlreq
 
 def escape(s, quote=None):
     '''Replace special characters "&", "<" and ">" to HTML-safe sequences.
     If the optional flag quote is true, the quotation mark character (")
     is also translated.
 
     This is the same as cgi.escape in Python, but always operates on
     bytes, whereas cgi.escape in Python 3 only works on unicodes.
     '''
     s = s.replace(b"&", b"&amp;")
     s = s.replace(b"<", b"&lt;")
     s = s.replace(b">", b"&gt;")
     if quote:
         s = s.replace(b'"', b"&quot;")
     return s
 
 class passwordmgr(object):
     def __init__(self, ui, passwddb):
         self.ui = ui
         self.passwddb = passwddb
 
     def add_password(self, realm, uri, user, passwd):
         return self.passwddb.add_password(realm, uri, user, passwd)
 
     def find_user_password(self, realm, authuri):
+        assert isinstance(realm, (type(None), str))
+        assert isinstance(authuri, str)
         authinfo = self.passwddb.find_user_password(realm, authuri)
         user, passwd = authinfo
         if user and passwd:
             self._writedebug(user, passwd)
             return (user, passwd)
 
         if not user or not passwd:
             res = httpconnectionmod.readauthforuri(self.ui, authuri, user)
             if res:
                 group, auth = res
                 user, passwd = auth.get('username'), auth.get('password')
                 self.ui.debug("using auth.%s.* for authentication\n" % group)
         if not user or not passwd:
             u = util.url(pycompat.bytesurl(authuri))
             u.query = None
             if not self.ui.interactive():
                 raise error.Abort(_('http authorization required for %s') %
                                   util.hidepassword(bytes(u)))
 
             self.ui.write(_("http authorization required for %s\n") %
                           util.hidepassword(bytes(u)))
             self.ui.write(_("realm: %s\n") % pycompat.bytesurl(realm))
             if user:
                 self.ui.write(_("user: %s\n") % user)
             else:
                 user = self.ui.prompt(_("user:"), default=None)
 
             if not passwd:
                 passwd = self.ui.getpass()
 
         self.passwddb.add_password(realm, authuri, user, passwd)
         self._writedebug(user, passwd)
         return (user, passwd)
 
     def _writedebug(self, user, passwd):
         msg = _('http auth: user %s, password %s\n')
         self.ui.debug(msg % (user, passwd and '*' * len(passwd) or 'not set'))
 
     def find_stored_password(self, authuri):
         return self.passwddb.find_user_password(None, authuri)
 
 class proxyhandler(urlreq.proxyhandler):
     def __init__(self, ui):
         proxyurl = (ui.config("http_proxy", "host") or
                         encoding.environ.get('http_proxy'))
         # XXX proxyauthinfo = None
 
         if proxyurl:
             # proxy can be proper url or host[:port]
             if not (proxyurl.startswith('http:') or
                     proxyurl.startswith('https:')):
                 proxyurl = 'http://' + proxyurl + '/'
             proxy = util.url(proxyurl)
             if not proxy.user:
                 proxy.user = ui.config("http_proxy", "user")
                 proxy.passwd = ui.config("http_proxy", "passwd")
 
             # see if we should use a proxy for this url
             no_list = ["localhost", "127.0.0.1"]
             no_list.extend([p.lower() for
                             p in ui.configlist("http_proxy", "no")])
             no_list.extend([p.strip().lower() for
                             p in encoding.environ.get("no_proxy", '').split(',')
                             if p.strip()])
             # "http_proxy.always" config is for running tests on localhost
             if ui.configbool("http_proxy", "always"):
                 self.no_list = []
             else:
                 self.no_list = no_list
 
             proxyurl = bytes(proxy)
             proxies = {'http': proxyurl, 'https': proxyurl}
             ui.debug('proxying through %s\n' % util.hidepassword(proxyurl))
         else:
             proxies = {}
 
         urlreq.proxyhandler.__init__(self, proxies)
         self.ui = ui
 
     def proxy_open(self, req, proxy, type_):
         host = urllibcompat.gethost(req).split(':')[0]
         for e in self.no_list:
             if host == e:
                 return None
             if e.startswith('*.') and host.endswith(e[2:]):
                 return None
             if e.startswith('.') and host.endswith(e[1:]):
                 return None
 
         return urlreq.proxyhandler.proxy_open(self, req, proxy, type_)
 
 def _gen_sendfile(orgsend):
     def _sendfile(self, data):
         # send a file
         if isinstance(data, httpconnectionmod.httpsendfile):
             # if auth required, some data sent twice, so rewind here
             data.seek(0)
             for chunk in util.filechunkiter(data):
                 orgsend(self, chunk)
         else:
             orgsend(self, data)
     return _sendfile
 
 has_https = util.safehasattr(urlreq, 'httpshandler')
 
 class httpconnection(keepalive.HTTPConnection):
     # must be able to send big bundle as stream.
     send = _gen_sendfile(keepalive.HTTPConnection.send)
 
     def getresponse(self):
         proxyres = getattr(self, 'proxyres', None)
         if proxyres:
             if proxyres.will_close:
                 self.close()
             self.proxyres = None
             return proxyres
         return keepalive.HTTPConnection.getresponse(self)
 
 # general transaction handler to support different ways to handle
 # HTTPS proxying before and after Python 2.6.3.
 def _generic_start_transaction(handler, h, req):
     tunnel_host = getattr(req, '_tunnel_host', None)
     if tunnel_host:
         if tunnel_host[:7] not in ['http://', 'https:/']:
             tunnel_host = 'https://' + tunnel_host
         new_tunnel = True
     else:
         tunnel_host = urllibcompat.getselector(req)
         new_tunnel = False
 
     if new_tunnel or tunnel_host == urllibcompat.getfullurl(req): # has proxy
         u = util.url(tunnel_host)
         if new_tunnel or u.scheme == 'https': # only use CONNECT for HTTPS
             h.realhostport = ':'.join([u.host, (u.port or '443')])
             h.headers = req.headers.copy()
             h.headers.update(handler.parent.addheaders)
             return
 
     h.realhostport = None
     h.headers = None
 
 def _generic_proxytunnel(self):
     proxyheaders = dict(
             [(x, self.headers[x]) for x in self.headers
              if x.lower().startswith('proxy-')])
     self.send('CONNECT %s HTTP/1.0\r\n' % self.realhostport)
     for header in proxyheaders.iteritems():
         self.send('%s: %s\r\n' % header)
     self.send('\r\n')
 
     # majority of the following code is duplicated from
     # httplib.HTTPConnection as there are no adequate places to
     # override functions to provide the needed functionality
     res = self.response_class(self.sock,
                               strict=self.strict,
                               method=self._method)
 
     while True:
         version, status, reason = res._read_status()
         if status != httplib.CONTINUE:
             break
         # skip lines that are all whitespace
         list(iter(lambda: res.fp.readline().strip(), ''))
     res.status = status
     res.reason = reason.strip()
 
     if res.status == 200:
         # skip lines until we find a blank line
         list(iter(res.fp.readline, '\r\n'))
         return True
 
     if version == 'HTTP/1.0':
         res.version = 10
     elif version.startswith('HTTP/1.'):
         res.version = 11
     elif version == 'HTTP/0.9':
         res.version = 9
     else:
         raise httplib.UnknownProtocol(version)
 
     if res.version == 9:
         res.length = None
         res.chunked = 0
         res.will_close = 1
         res.msg = httplib.HTTPMessage(stringio())
         return False
 
     res.msg = httplib.HTTPMessage(res.fp)
     res.msg.fp = None
 
     # are we using the chunked-style of transfer encoding?
     trenc = res.msg.getheader('transfer-encoding')
     if trenc and trenc.lower() == "chunked":
         res.chunked = 1
         res.chunk_left = None
     else:
         res.chunked = 0
 
     # will the connection close at the end of the response?
     res.will_close = res._check_close()
 
     # do we have a Content-Length?
     # NOTE: RFC 2616, section 4.4, #3 says we ignore this if
     # transfer-encoding is "chunked"
     length = res.msg.getheader('content-length')
     if length and not res.chunked:
         try:
             res.length = int(length)
         except ValueError:
             res.length = None
         else:
             if res.length < 0:  # ignore nonsensical negative lengths
                 res.length = None
     else:
         res.length = None
 
     # does the body have a fixed length? (of zero)
     if (status == httplib.NO_CONTENT or status == httplib.NOT_MODIFIED or
         100 <= status < 200 or # 1xx codes
         res._method == 'HEAD'):
         res.length = 0
 
     # if the connection remains open, and we aren't using chunked, and
     # a content-length was not provided, then assume that the connection
     # WILL close.
     if (not res.will_close and
        not res.chunked and
        res.length is None):
         res.will_close = 1
 
     self.proxyres = res
 
     return False
 
 class httphandler(keepalive.HTTPHandler):
     def http_open(self, req):
         return self.do_open(httpconnection, req)
 
     def _start_transaction(self, h, req):
         _generic_start_transaction(self, h, req)
         return keepalive.HTTPHandler._start_transaction(self, h, req)
 
 class logginghttpconnection(keepalive.HTTPConnection):
     def __init__(self, createconn, *args, **kwargs):
         keepalive.HTTPConnection.__init__(self, *args, **kwargs)
         self._create_connection = createconn
 
     if sys.version_info < (2, 7, 7):
         # copied from 2.7.14, since old implementations directly call
         # socket.create_connection()
         def connect(self):
             self.sock = self._create_connection((self.host, self.port),
                                                 self.timeout,
                                                 self.source_address)
             if self._tunnel_host:
                 self._tunnel()
 
 class logginghttphandler(httphandler):
     """HTTP handler that logs socket I/O."""
     def __init__(self, logfh, name, observeropts, timeout=None):
         super(logginghttphandler, self).__init__(timeout=timeout)
 
         self._logfh = logfh
         self._logname = name
         self._observeropts = observeropts
 
     # do_open() calls the passed class to instantiate an HTTPConnection. We
     # pass in a callable method that creates a custom HTTPConnection instance
     # whose callback to create the socket knows how to proxy the socket.
     def http_open(self, req):
         return self.do_open(self._makeconnection, req)
 
     def _makeconnection(self, *args, **kwargs):
         def createconnection(*args, **kwargs):
             sock = socket.create_connection(*args, **kwargs)
             return util.makeloggingsocket(self._logfh, sock, self._logname,
                                           **self._observeropts)
 
         return logginghttpconnection(createconnection, *args, **kwargs)
 
 if has_https:
     class httpsconnection(keepalive.HTTPConnection):
         response_class = keepalive.HTTPResponse
         default_port = httplib.HTTPS_PORT
         # must be able to send big bundle as stream.
         send = _gen_sendfile(keepalive.safesend)
         getresponse = keepalive.wrapgetresponse(httplib.HTTPConnection)
 
         def __init__(self, host, port=None, key_file=None, cert_file=None,
                      *args, **kwargs):
             keepalive.HTTPConnection.__init__(self, host, port, *args, **kwargs)
             self.key_file = key_file
             self.cert_file = cert_file
 
         def connect(self):
             self.sock = socket.create_connection((self.host, self.port))
 
             host = self.host
             if self.realhostport: # use CONNECT proxy
                 _generic_proxytunnel(self)
                 host = self.realhostport.rsplit(':', 1)[0]
             self.sock = sslutil.wrapsocket(
                 self.sock, self.key_file, self.cert_file, ui=self.ui,
                 serverhostname=host)
             sslutil.validatesocket(self.sock)
 
     class httpshandler(keepalive.KeepAliveHandler, urlreq.httpshandler):
         def __init__(self, ui, timeout=None):
             keepalive.KeepAliveHandler.__init__(self, timeout=timeout)
             urlreq.httpshandler.__init__(self)
             self.ui = ui
             self.pwmgr = passwordmgr(self.ui,
                                      self.ui.httppasswordmgrdb)
 
         def _start_transaction(self, h, req):
             _generic_start_transaction(self, h, req)
             return keepalive.KeepAliveHandler._start_transaction(self, h, req)
 
         def https_open(self, req):
             # urllibcompat.getfullurl() does not contain credentials
             # and we may need them to match the certificates.
             url = urllibcompat.getfullurl(req)
             user, password = self.pwmgr.find_stored_password(url)
             res = httpconnectionmod.readauthforuri(self.ui, url, user)
             if res:
                 group, auth = res
                 self.auth = auth
                 self.ui.debug("using auth.%s.* for authentication\n" % group)
             else:
                 self.auth = None
             return self.do_open(self._makeconnection, req)
 
         def _makeconnection(self, host, port=None, *args, **kwargs):
             keyfile = None
             certfile = None
 
             if len(args) >= 1: # key_file
                 keyfile = args[0]
             if len(args) >= 2: # cert_file
                 certfile = args[1]
             args = args[2:]
 
             # if the user has specified different key/cert files in
             # hgrc, we prefer these
             if self.auth and 'key' in self.auth and 'cert' in self.auth:
                 keyfile = self.auth['key']
                 certfile = self.auth['cert']
 
             conn = httpsconnection(host, port, keyfile, certfile, *args,
                                    **kwargs)
             conn.ui = self.ui
             return conn
 
 class httpdigestauthhandler(urlreq.httpdigestauthhandler):
     def __init__(self, *args, **kwargs):
         urlreq.httpdigestauthhandler.__init__(self, *args, **kwargs)
         self.retried_req = None
 
     def reset_retry_count(self):
         # Python 2.6.5 will call this on 401 or 407 errors and thus loop
         # forever. We disable reset_retry_count completely and reset in
         # http_error_auth_reqed instead.
         pass
 
     def http_error_auth_reqed(self, auth_header, host, req, headers):
         # Reset the retry counter once for each request.
         if req is not self.retried_req:
             self.retried_req = req
             self.retried = 0
         return urlreq.httpdigestauthhandler.http_error_auth_reqed(
                     self, auth_header, host, req, headers)
 
 class httpbasicauthhandler(urlreq.httpbasicauthhandler):
     def __init__(self, *args, **kwargs):
         self.auth = None
         urlreq.httpbasicauthhandler.__init__(self, *args, **kwargs)
         self.retried_req = None
 
     def http_request(self, request):
         if self.auth:
             request.add_unredirected_header(self.auth_header, self.auth)
 
         return request
 
     def https_request(self, request):
         if self.auth:
             request.add_unredirected_header(self.auth_header, self.auth)
 
         return request
 
     def reset_retry_count(self):
         # Python 2.6.5 will call this on 401 or 407 errors and thus loop
         # forever. We disable reset_retry_count completely and reset in
         # http_error_auth_reqed instead.
         pass
 
     def http_error_auth_reqed(self, auth_header, host, req, headers):
         # Reset the retry counter once for each request.
         if req is not self.retried_req:
             self.retried_req = req
             self.retried = 0
         return urlreq.httpbasicauthhandler.http_error_auth_reqed(
                         self, auth_header, host, req, headers)
 
     def retry_http_basic_auth(self, host, req, realm):
         user, pw = self.passwd.find_user_password(
             realm, urllibcompat.getfullurl(req))
         if pw is not None:
             raw = "%s:%s" % (pycompat.bytesurl(user), pycompat.bytesurl(pw))
             auth = r'Basic %s' % pycompat.strurl(base64.b64encode(raw).strip())
             if req.get_header(self.auth_header, None) == auth:
                 return None
             self.auth = auth
             req.add_unredirected_header(self.auth_header, auth)
             return self.parent.open(req)
         else:
             return None
 
 class cookiehandler(urlreq.basehandler):
     def __init__(self, ui):
         self.cookiejar = None
 
         cookiefile = ui.config('auth', 'cookiefile')
         if not cookiefile:
             return
 
         cookiefile = util.expandpath(cookiefile)
         try:
             cookiejar = util.cookielib.MozillaCookieJar(
                 pycompat.fsdecode(cookiefile))
             cookiejar.load()
             self.cookiejar = cookiejar
         except util.cookielib.LoadError as e:
             ui.warn(_('(error loading cookie file %s: %s; continuing without '
                       'cookies)\n') % (cookiefile, stringutil.forcebytestr(e)))
 
     def http_request(self, request):
         if self.cookiejar:
             self.cookiejar.add_cookie_header(request)
 
         return request
 
     def https_request(self, request):
         if self.cookiejar:
             self.cookiejar.add_cookie_header(request)
 
         return request
 
 handlerfuncs = []
 
 def opener(ui, authinfo=None, useragent=None, loggingfh=None,
            loggingname=b's', loggingopts=None, sendaccept=True):
     '''
     construct an opener suitable for urllib2
     authinfo will be added to the password manager
 
     The opener can be configured to log socket events if the various
     ``logging*`` arguments are specified.
 
     ``loggingfh`` denotes a file object to log events to.
     ``loggingname`` denotes the name of the to print when logging.
     ``loggingopts`` is a dict of keyword arguments to pass to the constructed
     ``util.socketobserver`` instance.
 
     ``sendaccept`` allows controlling whether the ``Accept`` request header
     is sent. The header is sent by default.
     '''
     timeout = ui.configwith(float, 'http', 'timeout')
     handlers = []
 
     if loggingfh:
         handlers.append(logginghttphandler(loggingfh, loggingname,
                                            loggingopts or {}, timeout=timeout))
         # We don't yet support HTTPS when logging I/O. If we attempt to open
         # an HTTPS URL, we'll likely fail due to unknown protocol.
 
     else:
         handlers.append(httphandler(timeout=timeout))
         if has_https:
             handlers.append(httpshandler(ui, timeout=timeout))
 
     handlers.append(proxyhandler(ui))
 
     passmgr = passwordmgr(ui, ui.httppasswordmgrdb)
     if authinfo is not None:
         realm, uris, user, passwd = authinfo
         saveduser, savedpass = passmgr.find_stored_password(uris[0])
         if user != saveduser or passwd:
             passmgr.add_password(realm, uris, user, passwd)
         ui.debug('http auth: user %s, password %s\n' %
                  (user, passwd and '*' * len(passwd) or 'not set'))
 
     handlers.extend((httpbasicauthhandler(passmgr),
                      httpdigestauthhandler(passmgr)))
     handlers.extend([h(ui, passmgr) for h in handlerfuncs])
     handlers.append(cookiehandler(ui))
     opener = urlreq.buildopener(*handlers)
 
     # keepalive.py's handlers will populate these attributes if they exist.
     opener.requestscount = 0
     opener.sentbytescount = 0
     opener.receivedbytescount = 0
 
     # The user agent should should *NOT* be used by servers for e.g.
     # protocol detection or feature negotiation: there are other
     # facilities for that.
     #
     # "mercurial/proto-1.0" was the original user agent string and
     # exists for backwards compatibility reasons.
     #
     # The "(Mercurial %s)" string contains the distribution
     # name and version. Other client implementations should choose their
     # own distribution name. Since servers should not be using the user
     # agent string for anything, clients should be able to define whatever
     # user agent they deem appropriate.
     #
     # The custom user agent is for lfs, because unfortunately some servers
     # do look at this value.
     if not useragent:
         agent = 'mercurial/proto-1.0 (Mercurial %s)' % util.version()
         opener.addheaders = [(r'User-agent', pycompat.sysstr(agent))]
     else:
         opener.addheaders = [(r'User-agent', pycompat.sysstr(useragent))]
 
     # This header should only be needed by wire protocol requests. But it has
     # been sent on all requests since forever. We keep sending it for backwards
     # compatibility reasons. Modern versions of the wire protocol use
     # X-HgProto-<N> for advertising client support.
     if sendaccept:
         opener.addheaders.append((r'Accept', r'application/mercurial-0.1'))
 
     return opener
 
 def open(ui, url_, data=None):
     u = util.url(url_)
     if u.scheme:
         u.scheme = u.scheme.lower()
         url_, authinfo = u.authinfo()
     else:
         path = util.normpath(os.path.abspath(url_))
         url_ = 'file://' + pycompat.bytesurl(urlreq.pathname2url(path))
         authinfo = None
     return opener(ui, authinfo).open(pycompat.strurl(url_), data)
 
 def wrapresponse(resp):
     """Wrap a response object with common error handlers.
 
     This ensures that any I/O from any consumer raises the appropriate
     error and messaging.
     """
     origread = resp.read
 
     class readerproxy(resp.__class__):
         def read(self, size=None):
             try:
                 return origread(size)
             except httplib.IncompleteRead as e:
                 # e.expected is an integer if length known or None otherwise.
                 if e.expected:
                     got = len(e.partial)
                     total = e.expected + got
                     msg = _('HTTP request error (incomplete response; '
                             'expected %d bytes got %d)') % (total, got)
                 else:
                     msg = _('HTTP request error (incomplete response)')
 
                 raise error.PeerTransportError(
                     msg,
                     hint=_('this may be an intermittent network failure; '
                            'if the error persists, consider contacting the '
                            'network or server operator'))
             except httplib.HTTPException as e:
                 raise error.PeerTransportError(
                     _('HTTP request error (%s)') % e,
                     hint=_('this may be an intermittent network failure; '
                            'if the error persists, consider contacting the '
                            'network or server operator'))
 
     resp.__class__ = readerproxy