mercurial/url.py

url: support client certificate files over HTTPS (issue643)

This extends the httpshandler with the means to utilise the auth
section to provide it with a PEM encoded certificate key file and
certificate chain file. This works also with sites that both require
client certificate authentication and basic or digest password
authentication, although the latter situation may require the user to
enter the PEM password multiple times.

# 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, incorporated herein by reference.

import urllib, urllib2, urlparse, httplib, os, re, socket, cStringIO
from i18n import _
import keepalive, util

def hidepassword(url):
    '''hide user credential in a url string'''
    scheme, netloc, path, params, query, fragment = urlparse.urlparse(url)
    netloc = re.sub('([^:]*):([^@]*)@(.*)', r'\1:***@\3', netloc)
    return urlparse.urlunparse((scheme, netloc, path, params, query, fragment))

def removeauth(url):
    '''remove all authentication information from a url string'''
    scheme, netloc, path, params, query, fragment = urlparse.urlparse(url)
    netloc = netloc[netloc.find('@')+1:]
    return urlparse.urlunparse((scheme, netloc, path, params, query, fragment))

def netlocsplit(netloc):
    '''split [user[:passwd]@]host[:port] into 4-tuple.'''

    a = netloc.find('@')
    if a == -1:
        user, passwd = None, None
    else:
        userpass, netloc = netloc[:a], netloc[a+1:]
        c = userpass.find(':')
        if c == -1:
            user, passwd = urllib.unquote(userpass), None
        else:
            user = urllib.unquote(userpass[:c])
            passwd = urllib.unquote(userpass[c+1:])
    c = netloc.find(':')
    if c == -1:
        host, port = netloc, None
    else:
        host, port = netloc[:c], netloc[c+1:]
    return host, port, user, passwd

def netlocunsplit(host, port, user=None, passwd=None):
    '''turn host, port, user, passwd into [user[:passwd]@]host[:port].'''
    if port:
        hostport = host + ':' + port
    else:
        hostport = host
    if user:
        if passwd:
            userpass = urllib.quote(user) + ':' + urllib.quote(passwd)
        else:
            userpass = urllib.quote(user)
        return userpass + '@' + hostport
    return hostport

_safe = ('abcdefghijklmnopqrstuvwxyz'
         'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
         '0123456789' '_.-/')
_safeset = None
_hex = None
def quotepath(path):
    '''quote the path part of a URL

    This is similar to urllib.quote, but it also tries to avoid
    quoting things twice (inspired by wget):

    >>> quotepath('abc def')
    'abc%20def'
    >>> quotepath('abc%20def')
    'abc%20def'
    >>> quotepath('abc%20 def')
    'abc%20%20def'
    >>> quotepath('abc def%20')
    'abc%20def%20'
    >>> quotepath('abc def%2')
    'abc%20def%252'
    >>> quotepath('abc def%')
    'abc%20def%25'
    '''
    global _safeset, _hex
    if _safeset is None:
        _safeset = set(_safe)
        _hex = set('abcdefABCDEF0123456789')
    l = list(path)
    for i in xrange(len(l)):
        c = l[i]
        if c == '%' and i + 2 < len(l) and (l[i+1] in _hex and l[i+2] in _hex):
            pass
        elif c not in _safeset:
            l[i] = '%%%02X' % ord(c)
    return ''.join(l)

class passwordmgr(urllib2.HTTPPasswordMgrWithDefaultRealm):
    def __init__(self, ui):
        urllib2.HTTPPasswordMgrWithDefaultRealm.__init__(self)
        self.ui = ui

    def find_user_password(self, realm, authuri):
        authinfo = urllib2.HTTPPasswordMgrWithDefaultRealm.find_user_password(
            self, realm, authuri)
        user, passwd = authinfo
        if user and passwd:
            self._writedebug(user, passwd)
            return (user, passwd)

        if not user:
            auth = self.readauthtoken(authuri)
            if auth:
                user, passwd = auth.get('username'), auth.get('password')
        if not user or not passwd:
            if not self.ui.interactive():
                raise util.Abort(_('http authorization required'))

            self.ui.write(_("http authorization required\n"))
            self.ui.status(_("realm: %s\n") % realm)
            if user:
                self.ui.status(_("user: %s\n") % user)
            else:
                user = self.ui.prompt(_("user:"), default=None)

            if not passwd:
                passwd = self.ui.getpass()

        self.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 readauthtoken(self, uri):
        # Read configuration
        config = dict()
        for key, val in self.ui.configitems('auth'):
            group, setting = key.split('.', 1)
            gdict = config.setdefault(group, dict())
            gdict[setting] = val

        # Find the best match
        scheme, hostpath = uri.split('://', 1)
        bestlen = 0
        bestauth = None
        for auth in config.itervalues():
            prefix = auth.get('prefix')
            if not prefix: continue
            p = prefix.split('://', 1)
            if len(p) > 1:
                schemes, prefix = [p[0]], p[1]
            else:
                schemes = (auth.get('schemes') or 'https').split()
            if (prefix == '*' or hostpath.startswith(prefix)) and \
                len(prefix) > bestlen and scheme in schemes:
                bestlen = len(prefix)
                bestauth = auth
        return bestauth

class proxyhandler(urllib2.ProxyHandler):
    def __init__(self, ui):
        proxyurl = ui.config("http_proxy", "host") or os.getenv('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 + '/'
            snpqf = urlparse.urlsplit(proxyurl)
            proxyscheme, proxynetloc, proxypath, proxyquery, proxyfrag = snpqf
            hpup = netlocsplit(proxynetloc)

            proxyhost, proxyport, proxyuser, proxypasswd = hpup
            if not proxyuser:
                proxyuser = ui.config("http_proxy", "user")
                proxypasswd = 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 os.getenv("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 = urlparse.urlunsplit((
                proxyscheme, netlocunsplit(proxyhost, proxyport,
                                                proxyuser, proxypasswd or ''),
                proxypath, proxyquery, proxyfrag))
            proxies = {'http': proxyurl, 'https': proxyurl}
            ui.debug(_('proxying through http://%s:%s\n') %
                      (proxyhost, proxyport))
        else:
            proxies = {}

        # urllib2 takes proxy values from the environment and those
        # will take precedence if found, so drop them
        for env in ["HTTP_PROXY", "http_proxy", "no_proxy"]:
            try:
                if env in os.environ:
                    del os.environ[env]
            except OSError:
                pass

        urllib2.ProxyHandler.__init__(self, proxies)
        self.ui = ui

    def proxy_open(self, req, proxy, type_):
        host = req.get_host().split(':')[0]
        if host in self.no_list:
            return None

        # work around a bug in Python < 2.4.2
        # (it leaves a "\n" at the end of Proxy-authorization headers)
        baseclass = req.__class__
        class _request(baseclass):
            def add_header(self, key, val):
                if key.lower() == 'proxy-authorization':
                    val = val.strip()
                return baseclass.add_header(self, key, val)
        req.__class__ = _request

        return urllib2.ProxyHandler.proxy_open(self, req, proxy, type_)

class httpsendfile(file):
    def __len__(self):
        return os.fstat(self.fileno()).st_size

def _gen_sendfile(connection):
    def _sendfile(self, data):
        # send a file
        if isinstance(data, httpsendfile):
            # if auth required, some data sent twice, so rewind here
            data.seek(0)
            for chunk in util.filechunkiter(data):
                connection.send(self, chunk)
        else:
            connection.send(self, data)
    return _sendfile

has_https = hasattr(urllib2, 'HTTPSHandler')
if has_https:
    try:
        # avoid using deprecated/broken FakeSocket in python 2.6
        import ssl
        _ssl_wrap_socket = ssl.wrap_socket
    except ImportError:
        def _ssl_wrap_socket(sock, key_file, cert_file):
            ssl = socket.ssl(sock, key_file, cert_file)
            return httplib.FakeSocket(sock, ssl)

class httpconnection(keepalive.HTTPConnection):
    # must be able to send big bundle as stream.
    send = _gen_sendfile(keepalive.HTTPConnection)

    def _proxytunnel(self):
        proxyheaders = dict(
                [(x, self.headers[x]) for x in self.headers
                 if x.lower().startswith('proxy-')])
        self._set_hostport(self.host, self.port)
        self.send('CONNECT %s:%d HTTP/1.0\r\n' % (self.realhost, self.realport))
        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
            while True:
                skip = res.fp.readline().strip()
                if not skip:
                    break
        res.status = status
        res.reason = reason.strip()

        if res.status == 200:
            while True:
                line = res.fp.readline()
                if line == '\r\n':
                    break
            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(cStringIO.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, S4.4, #3 says we ignore this if tr_enc 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

    def connect(self):
        if has_https and self.realhost: # use CONNECT proxy
            self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            self.sock.connect((self.host, self.port))
            if self._proxytunnel():
                # we do not support client x509 certificates
                self.sock = _ssl_wrap_socket(self.sock, None, None)
        else:
            keepalive.HTTPConnection.connect(self)

    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)

class httphandler(keepalive.HTTPHandler):
    def http_open(self, req):
        return self.do_open(httpconnection, req)

    def _start_transaction(self, h, req):
        if req.get_selector() == req.get_full_url(): # has proxy
            urlparts = urlparse.urlparse(req.get_selector())
            if urlparts[0] == 'https': # only use CONNECT for HTTPS
                if ':' in urlparts[1]:
                    realhost, realport = urlparts[1].split(':')
                else:
                    realhost = urlparts[1]
                    realport = 443

                h.realhost = realhost
                h.realport = realport
                h.headers = req.headers.copy()
                h.headers.update(self.parent.addheaders)
                return keepalive.HTTPHandler._start_transaction(self, h, req)

        h.realhost = None
        h.realport = None
        h.headers = None
        return keepalive.HTTPHandler._start_transaction(self, h, req)

    def __del__(self):
        self.close_all()

if has_https:
    class httpsconnection(httplib.HTTPSConnection):
        response_class = keepalive.HTTPResponse
        # must be able to send big bundle as stream.
        send = _gen_sendfile(httplib.HTTPSConnection)

    class httpshandler(keepalive.KeepAliveHandler, urllib2.HTTPSHandler):
        def __init__(self, ui):
            keepalive.KeepAliveHandler.__init__(self)
            urllib2.HTTPSHandler.__init__(self)
            self.ui = ui
            self.pwmgr = passwordmgr(self.ui)

        def https_open(self, req):
            self.auth = self.pwmgr.readauthtoken(req.get_full_url())
            return self.do_open(self._makeconnection, req)

        def _makeconnection(self, host, port=443, *args, **kwargs):
            keyfile = None
            certfile = None

            if args: # key_file
                keyfile = args.pop(0)
            if args: # cert_file
                certfile = args.pop(0)

            # 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']

            return httpsconnection(host, port, keyfile, certfile, *args, **kwargs)

# In python < 2.5 AbstractDigestAuthHandler raises a ValueError if
# it doesn't know about the auth type requested.  This can happen if
# somebody is using BasicAuth and types a bad password.
class httpdigestauthhandler(urllib2.HTTPDigestAuthHandler):
    def http_error_auth_reqed(self, auth_header, host, req, headers):
        try:
            return urllib2.HTTPDigestAuthHandler.http_error_auth_reqed(
                        self, auth_header, host, req, headers)
        except ValueError, inst:
            arg = inst.args[0]
            if arg.startswith("AbstractDigestAuthHandler doesn't know "):
                return
            raise

def getauthinfo(path):
    scheme, netloc, urlpath, query, frag = urlparse.urlsplit(path)
    if not urlpath:
        urlpath = '/'
    if scheme != 'file':
        # XXX: why are we quoting the path again with some smart
        # heuristic here? Anyway, it cannot be done with file://
        # urls since path encoding is os/fs dependent (see
        # urllib.pathname2url() for details).
        urlpath = quotepath(urlpath)
    host, port, user, passwd = netlocsplit(netloc)

    # urllib cannot handle URLs with embedded user or passwd
    url = urlparse.urlunsplit((scheme, netlocunsplit(host, port),
                              urlpath, query, frag))
    if user:
        netloc = host
        if port:
            netloc += ':' + port
        # Python < 2.4.3 uses only the netloc to search for a password
        authinfo = (None, (url, netloc), user, passwd or '')
    else:
        authinfo = None
    return url, authinfo

def opener(ui, authinfo=None):
    '''
    construct an opener suitable for urllib2
    authinfo will be added to the password manager
    '''
    handlers = [httphandler()]
    if has_https:
        handlers.append(httpshandler(ui))

    handlers.append(proxyhandler(ui))

    passmgr = passwordmgr(ui)
    if authinfo is not None:
        passmgr.add_password(*authinfo)
        user, passwd = authinfo[2:4]
        ui.debug(_('http auth: user %s, password %s\n') %
                 (user, passwd and '*' * len(passwd) or 'not set'))

    handlers.extend((urllib2.HTTPBasicAuthHandler(passmgr),
                     httpdigestauthhandler(passmgr)))
    opener = urllib2.build_opener(*handlers)

    # 1.0 here is the _protocol_ version
    opener.addheaders = [('User-agent', 'mercurial/proto-1.0')]
    opener.addheaders.append(('Accept', 'application/mercurial-0.1'))
    return opener

scheme_re = re.compile(r'^([a-zA-Z0-9+-.]+)://')

def open(ui, url, data=None):
    scheme = None
    m = scheme_re.search(url)
    if m:
        scheme = m.group(1).lower()
    if not scheme:
        path = util.normpath(os.path.abspath(url))
        url = 'file://' + urllib.pathname2url(path)
        authinfo = None
    else:
        url, authinfo = getauthinfo(url)
    return opener(ui, authinfo).open(url, data)