hgweb: centralize permission checks for protocol commands

Consistently enforces authorization checks set up in hgrc up front, so that
the actual commands don't have to worry about them and implementers of
hgweb alternatives can easily implement their own permission checks.

mercurial/hgweb/hgweb_mod.py

@@ -1,358 +1,390 b''
 # hgweb/hgweb_mod.py - Web interface for a repository.
 #
 # Copyright 21 May 2005 - (c) 2005 Jake Edge <[e-mail]>
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 import os, mimetypes
 from mercurial.node import hex, nullid
 from mercurial.repo import RepoError
 from mercurial import mdiff, ui, hg, util, patch, hook
 from mercurial import revlog, templater, templatefilters, changegroup
 from common import get_mtime, style_map, paritygen, countgen, ErrorResponse
 from common import HTTP_OK, HTTP_BAD_REQUEST, HTTP_NOT_FOUND, HTTP_SERVER_ERROR
 from request import wsgirequest
 import webcommands, protocol, webutil
 
+perms = {
+    'changegroup': 'pull',
+    'changegroupsubset': 'pull',
+    'unbundle': 'push',
+    'stream_out': 'pull',
+}
+
 class hgweb(object):
     def __init__(self, repo, name=None):
         if isinstance(repo, str):
             parentui = ui.ui(report_untrusted=False, interactive=False)
             self.repo = hg.repository(parentui, repo)
         else:
             self.repo = repo
 
         hook.redirect(True)
         self.mtime = -1
         self.reponame = name
         self.archives = 'zip', 'gz', 'bz2'
         self.stripecount = 1
         self._capabilities = None
         # a repo owner may set web.templates in .hg/hgrc to get any file
         # readable by the user running the CGI script
         self.templatepath = self.config("web", "templates",
                                         templater.templatepath(),
                                         untrusted=False)
 
     # The CGI scripts are often run by a user different from the repo owner.
     # Trust the settings from the .hg/hgrc files by default.
     def config(self, section, name, default=None, untrusted=True):
         return self.repo.ui.config(section, name, default,
                                    untrusted=untrusted)
 
     def configbool(self, section, name, default=False, untrusted=True):
         return self.repo.ui.configbool(section, name, default,
                                        untrusted=untrusted)
 
     def configlist(self, section, name, default=None, untrusted=True):
         return self.repo.ui.configlist(section, name, default,
                                        untrusted=untrusted)
 
     def refresh(self):
         mtime = get_mtime(self.repo.root)
         if mtime != self.mtime:
             self.mtime = mtime
             self.repo = hg.repository(self.repo.ui, self.repo.root)
             self.maxchanges = int(self.config("web", "maxchanges", 10))
             self.stripecount = int(self.config("web", "stripes", 1))
             self.maxshortchanges = int(self.config("web", "maxshortchanges", 60))
             self.maxfiles = int(self.config("web", "maxfiles", 10))
             self.allowpull = self.configbool("web", "allowpull", True)
             self.encoding = self.config("web", "encoding", util._encoding)
             self._capabilities = None
 
     def capabilities(self):
         if self._capabilities is not None:
             return self._capabilities
         caps = ['lookup', 'changegroupsubset']
         if self.configbool('server', 'uncompressed'):
             caps.append('stream=%d' % self.repo.changelog.version)
         if changegroup.bundlepriority:
             caps.append('unbundle=%s' % ','.join(changegroup.bundlepriority))
         self._capabilities = caps
         return caps
 
     def run(self):
         if not os.environ.get('GATEWAY_INTERFACE', '').startswith("CGI/1."):
             raise RuntimeError("This function is only intended to be called while running as a CGI script.")
         import mercurial.hgweb.wsgicgi as wsgicgi
         wsgicgi.launch(self)
 
     def __call__(self, env, respond):
         req = wsgirequest(env, respond)
         self.run_wsgi(req)
         return req
 
     def run_wsgi(self, req):
 
         self.refresh()
 
         # process this if it's a protocol request
         # protocol bits don't need to create any URLs
         # and the clients always use the old URL structure
 
         cmd = req.form.get('cmd', [''])[0]
         if cmd and cmd in protocol.__all__:
+            if cmd in perms and not self.check_perm(req, perms[cmd]):
+                return
             method = getattr(protocol, cmd)
             method(self, req)
             return
 
         # work with CGI variables to create coherent structure
         # use SCRIPT_NAME, PATH_INFO and QUERY_STRING as well as our REPO_NAME
 
         req.url = req.env['SCRIPT_NAME']
         if not req.url.endswith('/'):
             req.url += '/'
         if 'REPO_NAME' in req.env:
             req.url += req.env['REPO_NAME'] + '/'
 
         if 'PATH_INFO' in req.env:
             parts = req.env['PATH_INFO'].strip('/').split('/')
             repo_parts = req.env.get('REPO_NAME', '').split('/')
             if parts[:len(repo_parts)] == repo_parts:
                 parts = parts[len(repo_parts):]
             query = '/'.join(parts)
         else:
             query = req.env['QUERY_STRING'].split('&', 1)[0]
             query = query.split(';', 1)[0]
 
         # translate user-visible url structure to internal structure
 
         args = query.split('/', 2)
         if 'cmd' not in req.form and args and args[0]:
 
             cmd = args.pop(0)
             style = cmd.rfind('-')
             if style != -1:
                 req.form['style'] = [cmd[:style]]
                 cmd = cmd[style+1:]
 
             # avoid accepting e.g. style parameter as command
             if hasattr(webcommands, cmd):
                 req.form['cmd'] = [cmd]
             else:
                 cmd = ''
 
             if args and args[0]:
                 node = args.pop(0)
                 req.form['node'] = [node]
             if args:
                 req.form['file'] = args
 
             if cmd == 'static':
                 req.form['file'] = req.form['node']
             elif cmd == 'archive':
                 fn = req.form['node'][0]
                 for type_, spec in self.archive_specs.iteritems():
                     ext = spec[2]
                     if fn.endswith(ext):
                         req.form['node'] = [fn[:-len(ext)]]
                         req.form['type'] = [type_]
 
         # process the web interface request
 
         try:
 
             tmpl = self.templater(req)
             ctype = tmpl('mimetype', encoding=self.encoding)
             ctype = templater.stringify(ctype)
 
             if cmd == '':
                 req.form['cmd'] = [tmpl.cache['default']]
                 cmd = req.form['cmd'][0]
 
             if cmd not in webcommands.__all__:
                 msg = 'no such method: %s' % cmd
                 raise ErrorResponse(HTTP_BAD_REQUEST, msg)
             elif cmd == 'file' and 'raw' in req.form.get('style', []):
                 self.ctype = ctype
                 content = webcommands.rawfile(self, req, tmpl)
             else:
                 content = getattr(webcommands, cmd)(self, req, tmpl)
                 req.respond(HTTP_OK, ctype)
 
             req.write(content)
             del tmpl
 
         except revlog.LookupError, err:
             req.respond(HTTP_NOT_FOUND, ctype)
             msg = str(err)
             if 'manifest' not in msg:
                 msg = 'revision not found: %s' % err.name
             req.write(tmpl('error', error=msg))
         except (RepoError, revlog.RevlogError), inst:
             req.respond(HTTP_SERVER_ERROR, ctype)
             req.write(tmpl('error', error=str(inst)))
         except ErrorResponse, inst:
             req.respond(inst.code, ctype)
             req.write(tmpl('error', error=inst.message))
 
     def templater(self, req):
 
         # determine scheme, port and server name
         # this is needed to create absolute urls
 
         proto = req.env.get('wsgi.url_scheme')
         if proto == 'https':
             proto = 'https'
             default_port = "443"
         else:
             proto = 'http'
             default_port = "80"
 
         port = req.env["SERVER_PORT"]
         port = port != default_port and (":" + port) or ""
         urlbase = '%s://%s%s' % (proto, req.env['SERVER_NAME'], port)
         staticurl = self.config("web", "staticurl") or req.url + 'static/'
         if not staticurl.endswith('/'):
             staticurl += '/'
 
         # some functions for the templater
 
         def header(**map):
             yield tmpl('header', encoding=self.encoding, **map)
 
         def footer(**map):
             yield tmpl("footer", **map)
 
         def motd(**map):
             yield self.config("web", "motd", "")
 
         def sessionvars(**map):
             fields = []
             if 'style' in req.form:
                 style = req.form['style'][0]
                 if style != self.config('web', 'style', ''):
                     fields.append(('style', style))
 
             separator = req.url[-1] == '?' and ';' or '?'
             for name, value in fields:
                 yield dict(name=name, value=value, separator=separator)
                 separator = ';'
 
         # figure out which style to use
 
         style = self.config("web", "style", "")
         if 'style' in req.form:
             style = req.form['style'][0]
         mapfile = style_map(self.templatepath, style)
 
         if not self.reponame:
             self.reponame = (self.config("web", "name")
                              or req.env.get('REPO_NAME')
                              or req.url.strip('/') or self.repo.root)
 
         # create the templater
 
         tmpl = templater.templater(mapfile, templatefilters.filters,
                                    defaults={"url": req.url,
                                              "staticurl": staticurl,
                                              "urlbase": urlbase,
                                              "repo": self.reponame,
                                              "header": header,
                                              "footer": footer,
                                              "motd": motd,
                                              "sessionvars": sessionvars
                                             })
         return tmpl
 
     def archivelist(self, nodeid):
         allowed = self.configlist("web", "allow_archive")
         for i, spec in self.archive_specs.iteritems():
             if i in allowed or self.configbool("web", "allow" + i):
                 yield {"type" : i, "extension" : spec[2], "node" : nodeid}
 
     def listfilediffs(self, tmpl, files, changeset):
         for f in files[:self.maxfiles]:
             yield tmpl("filedifflink", node=hex(changeset), file=f)
         if len(files) > self.maxfiles:
             yield tmpl("fileellipses")
 
     def diff(self, tmpl, node1, node2, files):
         def filterfiles(filters, files):
             l = [x for x in files if x in filters]
 
             for t in filters:
                 if t and t[-1] != os.sep:
                     t += os.sep
                 l += [x for x in files if x.startswith(t)]
             return l
 
         parity = paritygen(self.stripecount)
         def diffblock(diff, f, fn):
             yield tmpl("diffblock",
                        lines=prettyprintlines(diff),
                        parity=parity.next(),
                        file=f,
                        filenode=hex(fn or nullid))
 
         blockcount = countgen()
         def prettyprintlines(diff):
             blockno = blockcount.next()
             for lineno, l in enumerate(diff.splitlines(1)):
                 if blockno == 0:
                     lineno = lineno + 1
                 else:
                     lineno = "%d.%d" % (blockno, lineno + 1)
                 if l.startswith('+'):
                     ltype = "difflineplus"
                 elif l.startswith('-'):
                     ltype = "difflineminus"
                 elif l.startswith('@'):
                     ltype = "difflineat"
                 else:
                     ltype = "diffline"
                 yield tmpl(ltype,
                            line=l,
                            lineid="l%s" % lineno,
                            linenumber="% 8s" % lineno)
 
         r = self.repo
         c1 = r[node1]
         c2 = r[node2]
         date1 = util.datestr(c1.date())
         date2 = util.datestr(c2.date())
 
         modified, added, removed, deleted, unknown = r.status(node1, node2)[:5]
         if files:
             modified, added, removed = map(lambda x: filterfiles(files, x),
                                            (modified, added, removed))
 
         diffopts = patch.diffopts(self.repo.ui, untrusted=True)
         for f in modified:
             to = c1.filectx(f).data()
             tn = c2.filectx(f).data()
             yield diffblock(mdiff.unidiff(to, date1, tn, date2, f, f,
                                           opts=diffopts), f, tn)
         for f in added:
             to = None
             tn = c2.filectx(f).data()
             yield diffblock(mdiff.unidiff(to, date1, tn, date2, f, f,
                                           opts=diffopts), f, tn)
         for f in removed:
             to = c1.filectx(f).data()
             tn = None
             yield diffblock(mdiff.unidiff(to, date1, tn, date2, f, f,
                                           opts=diffopts), f, tn)
 
     archive_specs = {
         'bz2': ('application/x-tar', 'tbz2', '.tar.bz2', None),
         'gz': ('application/x-tar', 'tgz', '.tar.gz', None),
         'zip': ('application/zip', 'zip', '.zip', None),
         }
 
-    def check_perm(self, req, op, default):
-        '''check permission for operation based on user auth.
-        return true if op allowed, else false.
-        default is policy to use if no config given.'''
+    def check_perm(self, req, op):
+        '''Check permission for operation based on request data (including
+        authentication info. Return true if op allowed, else false.'''
+
+        def error(status, message):
+            req.respond(status, protocol.HGTYPE)
+            req.write('0\n%s\n' % message)
+
+        if op == 'pull':
+            return self.allowpull
+
+        # enforce that you can only push using POST requests
+        if req.env['REQUEST_METHOD'] != 'POST':
+            error('405 Method Not Allowed', 'push requires POST request')
+            return False
+
+        # require ssl by default for pushing, auth info cannot be sniffed
+        # and replayed
+        scheme = req.env.get('wsgi.url_scheme')
+        if self.configbool('web', 'push_ssl', True) and scheme != 'https':
+            error(HTTP_OK, 'ssl required')
+            return False
 
         user = req.env.get('REMOTE_USER')
 
-        deny = self.configlist('web', 'deny_' + op)
+        deny = self.configlist('web', 'deny_push')
         if deny and (not user or deny == ['*'] or user in deny):
+            error('401 Unauthorized', 'push not authorized')
             return False
 
-        allow = self.configlist('web', 'allow_' + op)
-        return (allow and (allow == ['*'] or user in allow)) or default
+        allow = self.configlist('web', 'allow_push')
+        result = allow and (allow == ['*'] or user in allow)
+        if not result:
+            error('401 Unauthorized', 'push not authorized')
+
+        return result

mercurial/hgweb/protocol.py

@@ -1,230 +1,203 b''
 #
 # Copyright 21 May 2005 - (c) 2005 Jake Edge <[e-mail]>
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 import cStringIO, zlib, tempfile, errno, os, sys
 from mercurial import util, streamclone
 from mercurial.node import bin, hex
 from mercurial import changegroup as changegroupmod
 from common import HTTP_OK, HTTP_NOT_FOUND, HTTP_SERVER_ERROR
 
 # __all__ is populated with the allowed commands. Be sure to add to it if
 # you're adding a new command, or the new command won't work.
 
 __all__ = [
    'lookup', 'heads', 'branches', 'between', 'changegroup',
    'changegroupsubset', 'capabilities', 'unbundle', 'stream_out',
 ]
 
 HGTYPE = 'application/mercurial-0.1'
 
 def lookup(web, req):
     try:
         r = hex(web.repo.lookup(req.form['key'][0]))
         success = 1
     except Exception,inst:
         r = str(inst)
         success = 0
     resp = "%s %s\n" % (success, r)
     req.respond(HTTP_OK, HGTYPE, length=len(resp))
     req.write(resp)
 
 def heads(web, req):
     resp = " ".join(map(hex, web.repo.heads())) + "\n"
     req.respond(HTTP_OK, HGTYPE, length=len(resp))
     req.write(resp)
 
 def branches(web, req):
     nodes = []
     if 'nodes' in req.form:
         nodes = map(bin, req.form['nodes'][0].split(" "))
     resp = cStringIO.StringIO()
     for b in web.repo.branches(nodes):
         resp.write(" ".join(map(hex, b)) + "\n")
     resp = resp.getvalue()
     req.respond(HTTP_OK, HGTYPE, length=len(resp))
     req.write(resp)
 
 def between(web, req):
     if 'pairs' in req.form:
         pairs = [map(bin, p.split("-"))
                  for p in req.form['pairs'][0].split(" ")]
     resp = cStringIO.StringIO()
     for b in web.repo.between(pairs):
         resp.write(" ".join(map(hex, b)) + "\n")
     resp = resp.getvalue()
     req.respond(HTTP_OK, HGTYPE, length=len(resp))
     req.write(resp)
 
 def changegroup(web, req):
     req.respond(HTTP_OK, HGTYPE)
     nodes = []
-    if not web.allowpull:
-        return
 
     if 'roots' in req.form:
         nodes = map(bin, req.form['roots'][0].split(" "))
 
     z = zlib.compressobj()
     f = web.repo.changegroup(nodes, 'serve')
     while 1:
         chunk = f.read(4096)
         if not chunk:
             break
         req.write(z.compress(chunk))
 
     req.write(z.flush())
 
 def changegroupsubset(web, req):
     req.respond(HTTP_OK, HGTYPE)
     bases = []
     heads = []
-    if not web.allowpull:
-        return
 
     if 'bases' in req.form:
         bases = [bin(x) for x in req.form['bases'][0].split(' ')]
     if 'heads' in req.form:
         heads = [bin(x) for x in req.form['heads'][0].split(' ')]
 
     z = zlib.compressobj()
     f = web.repo.changegroupsubset(bases, heads, 'serve')
     while 1:
         chunk = f.read(4096)
         if not chunk:
             break
         req.write(z.compress(chunk))
 
     req.write(z.flush())
 
 def capabilities(web, req):
     resp = ' '.join(web.capabilities())
     req.respond(HTTP_OK, HGTYPE, length=len(resp))
     req.write(resp)
 
 def unbundle(web, req):
 
     def bail(response, headers={}):
         length = int(req.env.get('CONTENT_LENGTH', 0))
         for s in util.filechunkiter(req, limit=length):
             # drain incoming bundle, else client will not see
             # response when run outside cgi script
             pass
 
         status = headers.pop('status', HTTP_OK)
         req.header(headers.items())
         req.respond(status, HGTYPE)
         req.write('0\n')
         req.write(response)
 
-    # enforce that you can only unbundle with POST requests
-    if req.env['REQUEST_METHOD'] != 'POST':
-        headers = {'status': '405 Method Not Allowed'}
-        bail('unbundle requires POST request\n', headers)
-        return
-
-    # require ssl by default, auth info cannot be sniffed and
-    # replayed
-    ssl_req = web.configbool('web', 'push_ssl', True)
-    if ssl_req:
-        if req.env.get('wsgi.url_scheme') != 'https':
-            bail('ssl required\n')
-            return
-        proto = 'https'
-    else:
-        proto = 'http'
-
-    # do not allow push unless explicitly allowed
-    if not web.check_perm(req, 'push', False):
-        bail('push not authorized\n', headers={'status': '401 Unauthorized'})
-        return
-
+    proto = req.env.get('wsgi.url_scheme') or 'http'
     their_heads = req.form['heads'][0].split(' ')
 
     def check_heads():
         heads = map(hex, web.repo.heads())
         return their_heads == [hex('force')] or their_heads == heads
 
     # fail early if possible
     if not check_heads():
         bail('unsynced changes\n')
         return
 
     req.respond(HTTP_OK, HGTYPE)
 
     # do not lock repo until all changegroup data is
     # streamed. save to temporary file.
 
     fd, tempname = tempfile.mkstemp(prefix='hg-unbundle-')
     fp = os.fdopen(fd, 'wb+')
     try:
         length = int(req.env['CONTENT_LENGTH'])
         for s in util.filechunkiter(req, limit=length):
             fp.write(s)
 
         try:
             lock = web.repo.lock()
             try:
                 if not check_heads():
                     req.write('0\n')
                     req.write('unsynced changes\n')
                     return
 
                 fp.seek(0)
                 header = fp.read(6)
                 if header.startswith('HG') and not header.startswith('HG10'):
                     raise ValueError('unknown bundle version')
                 elif header not in changegroupmod.bundletypes:
                     raise ValueError('unknown bundle compression type')
                 gen = changegroupmod.unbundle(header, fp)
 
                 # send addchangegroup output to client
 
                 oldio = sys.stdout, sys.stderr
                 sys.stderr = sys.stdout = cStringIO.StringIO()
 
                 try:
                     url = 'remote:%s:%s' % (proto,
                                             req.env.get('REMOTE_HOST', ''))
                     try:
                         ret = web.repo.addchangegroup(gen, 'serve', url)
                     except util.Abort, inst:
                         sys.stdout.write("abort: %s\n" % inst)
                         ret = 0
                 finally:
                     val = sys.stdout.getvalue()
                     sys.stdout, sys.stderr = oldio
                 req.write('%d\n' % ret)
                 req.write(val)
             finally:
                 del lock
         except ValueError, inst:
             req.write('0\n')
             req.write(str(inst) + '\n')
         except (OSError, IOError), inst:
             req.write('0\n')
             filename = getattr(inst, 'filename', '')
             # Don't send our filesystem layout to the client
             if filename.startswith(web.repo.root):
                 filename = filename[len(web.repo.root)+1:]
             else:
                 filename = ''
             error = getattr(inst, 'strerror', 'Unknown error')
             if inst.errno == errno.ENOENT:
                 code = HTTP_NOT_FOUND
             else:
                 code = HTTP_SERVER_ERROR
             req.respond(code)
             req.write('%s: %s\n' % (error, filename))
     finally:
         fp.close()
         os.unlink(tempname)
 
 def stream_out(web, req):
-    if not web.allowpull:
-        return
     req.respond(HTTP_OK, HGTYPE)
     streamclone.stream_out(web.repo, req, untrusted=True)