X-Git-Url: https://code.communitydata.science/nu-vpn-proxy.git/blobdiff_plain/8ca97e5bdb0ca26aa77f3ea2c4b533173a590676..refs/heads/master:/gp-saml-gui.py?ds=inline

diff --git a/gp-saml-gui.py b/gp-saml-gui.py
index 8bcf6f5..f540a3b 100755
--- a/gp-saml-gui.py
+++ b/gp-saml-gui.py
@@ -1,26 +1,52 @@
 #!/usr/bin/env python3
 
-import gi
+try:
+    import gi
+    gi.require_version('Gtk', '3.0')
+    gi.require_version('WebKit2', '4.0')
+    from gi.repository import Gtk, WebKit2, GLib
+except ImportError:
+    try:
+        import pgi as gi
+        gi.require_version('Gtk', '3.0')
+        gi.require_version('WebKit2', '4.0')
+        from pgi.repository import Gtk, WebKit2, GLib
+    except ImportError:
+        gi = None
+if gi is None:
+    raise ImportError("Either gi (PyGObject) or pgi module is required.")
+
 import argparse
-import pprint
-import urllib
+import urllib3
 import requests
 import xml.etree.ElementTree as ET
 import ssl
+import tempfile
 
 from operator import setitem
-from os import path
+from os import path, dup2, execvp
 from shlex import quote
-from sys import stderr
+from sys import stderr, platform
 from binascii import a2b_base64, b2a_base64
-from urllib.parse import urlparse
+from urllib.parse import urlparse, urlencode
+from html.parser import HTMLParser
+
+
+class CommentHtmlParser(HTMLParser):
+    def __init__(self):
+        super().__init__()
+        self.comments = []
+
+    def handle_comment(self, data: str) -> None:
+        self.comments.append(data)
+
+
+COOKIE_FIELDS = ('prelogin-cookie', 'portal-userauthcookie')
 
-gi.require_version('Gtk', '3.0')
-gi.require_version('WebKit2', '4.0')
-from gi.repository import Gtk, WebKit2, GLib
 
 class SAMLLoginView:
-    def __init__(self, uri, html=None, verbose=False, cookies=None, verify=True):
+    def __init__(self, uri, html=None, verbose=False, cookies=None, verify=True, user_agent=None):
+        Gtk.init(None)
         window = Gtk.Window()
 
         # API reference: https://lazka.github.io/pgi-docs/#WebKit2-4.0
@@ -31,20 +57,26 @@ class SAMLLoginView:
         self.verbose = verbose
 
         self.ctx = WebKit2.WebContext.get_default()
-        if not args.verify:
+        if not verify:
             self.ctx.set_tls_errors_policy(WebKit2.TLSErrorsPolicy.IGNORE)
         self.cookies = self.ctx.get_cookie_manager()
-        if args.cookies:
+        if cookies:
             self.cookies.set_accept_policy(WebKit2.CookieAcceptPolicy.ALWAYS)
-            self.cookies.set_persistent_storage(args.cookies, WebKit2.CookiePersistentStorage.TEXT)
+            self.cookies.set_persistent_storage(cookies, WebKit2.CookiePersistentStorage.TEXT)
         self.wview = WebKit2.WebView()
 
+        if user_agent is None:
+            user_agent = 'PAN GlobalProtect'
+        settings = self.wview.get_settings()
+        settings.set_user_agent(user_agent)
+        self.wview.set_settings(settings)
+
         window.resize(500, 500)
         window.add(self.wview)
         window.show_all()
         window.set_title("SAML Login")
         window.connect('delete-event', self.close)
-        self.wview.connect('load-changed', self.get_saml_headers)
+        self.wview.connect('load-changed', self.on_load_changed)
         self.wview.connect('resource-load-started', self.log_resources)
 
         if html:
@@ -84,44 +116,117 @@ class SAMLLoginView:
         if charset or content_type.startswith('text/'):
             print(data.decode(charset or 'utf-8'), file=stderr)
 
-    def get_saml_headers(self, webview, event):
+    def on_load_changed(self, webview, event):
         if event != WebKit2.LoadEvent.FINISHED:
             return
 
         mr = webview.get_main_resource()
         uri = mr.get_uri()
         rs = mr.get_response()
-        h = rs.get_http_headers()
+        h = rs.get_http_headers() if rs else None
+        ct = h.get_content_type()
+
         if self.verbose:
             print('[PAGE   ] Finished loading page %s' % uri, file=stderr)
-        if not h:
-            return
 
         # convert to normal dict
         d = {}
-        h.foreach(lambda k, v: setitem(d, k, v))
+        h.foreach(lambda k, v: setitem(d, k.lower(), v))
         # filter to interesting headers
-        fd = {name:v for name, v in d.items() if name.startswith('saml-') or name in ('prelogin-cookie', 'portal-userauthcookie')}
-        if fd and self.verbose:
-            print("[SAML   ] Got SAML result headers: %r" % fd, file=stderr)
+        fd = {name: v for name, v in d.items() if name.startswith('saml-') or name in COOKIE_FIELDS}
+
+        if fd:
+            if self.verbose:
+                print("[SAML   ] Got SAML result headers: %r" % fd, file=stderr)
+                if self.verbose > 1:
+                    # display everything we found
+                    mr.get_data(None, self.log_resource_text, ct[0], ct.params.get('charset'), d)
+            self.saml_result.update(fd, server=urlparse(uri).netloc)
+            self.check_done()
+
+        if not self.success:
             if self.verbose > 1:
-                # display everything we found
-                ct = h.get_content_type()
-                mr.get_data(None, self.log_resource_text, ct[0], ct.params.get('charset'), d)
+                print("[SAML   ] No headers in response, searching body for xml comments", file=stderr)
+            # asynchronous call to fetch body content, continue processing in callback:
+            mr.get_data(None, self.response_callback, ct)
+
+    def response_callback(self, resource, result, ct):
+        data = resource.get_data_finish(result)
+        content = data.decode(ct.params.get("charset") or "utf-8")
 
-        # check if we're done
-        self.saml_result.update(fd, server=urlparse(uri).netloc)
-        GLib.timeout_add(1000, self.check_done)
+        html_parser = CommentHtmlParser()
+        html_parser.feed(content)
+
+        fd = {}
+        for comment in html_parser.comments:
+            if self.verbose > 1:
+                print("[SAML   ] Found comment in response body: '%s'" % comment, file=stderr)
+            try:
+                # xml parser requires valid xml with a single root tag, but our expected content
+                # is just a list of data tags, so we need to improvise
+                xmlroot = ET.fromstring("<fakexmlroot>%s</fakexmlroot>" % comment)
+                # search for any valid first level xml tags (inside our fake root) that could contain SAML data
+                for elem in xmlroot:
+                    if elem.tag.startswith("saml-") or elem.tag in COOKIE_FIELDS:
+                        fd[elem.tag] = elem.text
+            except ET.ParseError:
+                pass  # silently ignore any comments that don't contain valid xml
+
+        if self.verbose > 1:
+            print("[SAML   ] Finished parsing response body for %s" % resource.get_uri(), file=stderr)
+        if fd:
+            if self.verbose:
+                print("[SAML   ] Got SAML result tags: %s" % fd, file=stderr)
+            self.saml_result.update(fd, server=urlparse(resource.get_uri()).netloc)
+
+        if not self.check_done():
+            # Work around timing/race condition by retrying check_done after 1 second
+            GLib.timeout_add(1000, self.check_done)
 
     def check_done(self):
         d = self.saml_result
         if 'saml-username' in d and ('prelogin-cookie' in d or 'portal-userauthcookie' in d):
-            if args.verbose:
+            if self.verbose:
                 print("[SAML   ] Got all required SAML headers, done.", file=stderr)
             self.success = True
             Gtk.main_quit()
+            return True
+
+
+class TLSAdapter(requests.adapters.HTTPAdapter):
+    '''Adapt to older TLS stacks that would raise errors otherwise.
+
+    We try to work around different issues:
+    * Enable weak ciphers such as 3DES or RC4, that have been disabled by default
+      in OpenSSL 3.0 or recent Linux distributions.
+    * Enable weak Diffie-Hellman key exchange sizes.
+    * Enable unsafe legacy renegotiation for servers without RFC 5746 support.
+
+    See Also
+    --------
+    https://github.com/psf/requests/issues/4775#issuecomment-478198879
+
+    Notes
+    -----
+    Python is missing an ssl.OP_LEGACY_SERVER_CONNECT constant.
+    We have extracted the relevant value from <openssl/ssl.h>.
+
+    '''
+    def init_poolmanager(self, connections, maxsize, block=False):
+        ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+        ssl_context.set_ciphers('DEFAULT:@SECLEVEL=1')
+        ssl_context.options |= 1<<2  # OP_LEGACY_SERVER_CONNECT
+        self.poolmanager = urllib3.PoolManager(
+                num_pools=connections,
+                maxsize=maxsize,
+                block=block,
+                ssl_context=ssl_context)
 
 def parse_args(args = None):
+    pf2clientos = dict(linux='Linux', darwin='Mac', win32='Windows', cygwin='Windows')
+    clientos2ocos = dict(Linux='linux-64', Mac='mac-intel', Windows='win')
+    default_clientos = pf2clientos.get(platform, 'Windows')
+
     p = argparse.ArgumentParser()
     p.add_argument('server', help='GlobalProtect server (portal or gateway)')
     p.add_argument('--no-verify', dest='verify', action='store_false', default=True, help='Ignore invalid server certificate')
@@ -131,18 +236,33 @@ def parse_args(args = None):
     x.add_argument('-K', '--no-cookies', dest='cookies', action='store_const', const=None,
                    help="Don't use or store cookies at all")
     x = p.add_mutually_exclusive_group()
-    x.add_argument('-p','--portal', dest='portal', action='store_true', help='SAML auth to portal')
-    x.add_argument('-g','--gateway', dest='portal', action='store_false', help='SAML auth to gateway (default)')
+    x.add_argument('-g','--gateway', dest='interface', action='store_const', const='gateway', default='portal',
+                   help='SAML auth to gateway')
+    x.add_argument('-p','--portal', dest='interface', action='store_const', const='portal',
+                   help='SAML auth to portal (default)')
     g = p.add_argument_group('Client certificate')
     g.add_argument('-c','--cert', help='PEM file containing client certificate (and optionally private key)')
     g.add_argument('--key', help='PEM file containing client private key (if not included in same file as certificate)')
     g = p.add_argument_group('Debugging and advanced options')
-    g.add_argument('-v','--verbose', default=0, action='count')
-    g.add_argument('-x','--external', action='store_true', help='Launch external browser (for debugging)')
+    x = p.add_mutually_exclusive_group()
+    x.add_argument('-v','--verbose', default=1, action='count', help='Increase verbosity of explanatory output to stderr')
+    x.add_argument('-q','--quiet', dest='verbose', action='store_const', const=0, help='Reduce verbosity to a minimum')
+    x = p.add_mutually_exclusive_group()
+    x.add_argument('-x','--external', action='store_true', help='Launch external browser (for debugging)')
+    x.add_argument('-P','--pkexec-openconnect', action='store_const', dest='exec', const='pkexec', help='Use PolicyKit to exec openconnect')
+    x.add_argument('-S','--sudo-openconnect', action='store_const', dest='exec', const='sudo', help='Use sudo to exec openconnect')
     g.add_argument('-u','--uri', action='store_true', help='Treat server as the complete URI of the SAML entry point, rather than GlobalProtect server')
-    p.add_argument('extra', nargs='*', help='Extra form field(s) to pass to include in the login query string (e.g. "magic-cookie-value=deadbeef01234567")')
-    args = p.parse_args(args = None)
-
+    g.add_argument('--clientos', choices=set(pf2clientos.values()), default=default_clientos, help="clientos value to send (default is %(default)s)")
+    p.add_argument('-f','--field', dest='extra', action='append', default=[],
+                   help='Extra form field(s) to pass to include in the login query string (e.g. "-f magic-cookie-value=deadbeef01234567")')
+    p.add_argument('--allow-insecure-crypto', dest='insecure', action='store_true',
+                   help='Allow use of insecure renegotiation or ancient 3DES and RC4 ciphers')
+    p.add_argument('--user-agent', '--useragent', default='PAN GlobalProtect',
+                   help='Use the provided string as the HTTP User-Agent header (default is %(default)r, as used by OpenConnect)')
+    p.add_argument('openconnect_extra', nargs='*', help="Extra arguments to include in output OpenConnect command-line")
+    args = p.parse_args(args)
+
+    args.ocos = clientos2ocos[args.clientos]
     args.extra = dict(x.split('=', 1) for x in args.extra)
 
     if args.cookies:
@@ -159,22 +279,28 @@ def parse_args(args = None):
 
     return p, args
 
-if __name__ == "__main__":
-    p, args = parse_args()
+def main(args = None):
+    p, args = parse_args(args)
 
     s = requests.Session()
-    s.headers['User-Agent'] = 'PAN GlobalProtect'
+    if args.insecure:
+        s.mount('https://', TLSAdapter())
+    s.headers['User-Agent'] = 'PAN GlobalProtect' if args.user_agent is None else args.user_agent
     s.cert = args.cert
 
+    if2prelogin = {'portal':'global-protect/prelogin.esp','gateway':'ssl-vpn/prelogin.esp'}
+    if2auth = {'portal':'global-protect/getconfig.esp','gateway':'ssl-vpn/login.esp'}
+
     # query prelogin.esp and parse SAML bits
     if args.uri:
         sam, uri, html = 'URI', args.server, None
     else:
-        endpoint = 'https://{}/{}/prelogin.esp'.format(args.server, ('global-protect' if args.portal else 'ssl-vpn'))
+        endpoint = 'https://{}/{}'.format(args.server, if2prelogin[args.interface])
+        data = {'tmp':'tmp', 'kerberos-support':'yes', 'ipv6-support':'yes', 'clientVer':4100, 'clientos':args.clientos, **args.extra}
         if args.verbose:
             print("Looking for SAML auth tags in response to %s..." % endpoint, file=stderr)
         try:
-            res = s.post(endpoint, verify=args.verify, data=args.extra)
+            res = s.post(endpoint, verify=args.verify, data=data)
         except Exception as ex:
             rootex = ex
             while True:
@@ -186,14 +312,27 @@ if __name__ == "__main__":
             if isinstance(rootex, ssl.CertificateError):
                 p.error("SSL certificate error (try --no-verify to ignore): %s" % rootex)
             elif isinstance(rootex, ssl.SSLError):
-                p.error("SSL error: %s" % rootex)
+                p.error("SSL error (try --allow-insecure-crypto to ignore): %s" % rootex)
             else:
                 raise
         xml = ET.fromstring(res.content)
+        if xml.tag != 'prelogin-response':
+            p.error("This does not appear to be a GlobalProtect prelogin response\nCheck in browser: {}?{}".format(endpoint, urlencode(data)))
+        status = xml.find('status')
+        if status != None and status.text != 'Success':
+            msg = xml.find('msg')
+            if msg != None and msg.text == 'GlobalProtect {} does not exist'.format(args.interface):
+                p.error("{} interface does not exist; specify {} instead".format(
+                    args.interface.title(), '--portal' if args.interface=='gateway' else '--gateway'))
+            else:
+                p.error("Error in {} prelogin response: {}".format(args.interface, msg.text))
         sam = xml.find('saml-auth-method')
         sr = xml.find('saml-request')
         if sam is None or sr is None:
-            p.error("This does not appear to be a SAML prelogin response (<saml-auth-method> or <saml-request> tags missing)")
+            p.error("{} prelogin response does not contain SAML tags (<saml-auth-method> or <saml-request> missing)\n\n"
+                    "Things to try:\n"
+                    "1) Spoof an officially supported OS (e.g. --clientos=Windows or --clientos=Mac)\n"
+                    "2) Check in browser: {}?{}".format(args.interface.title(), endpoint, urlencode(data)))
         sam = sam.text
         sr = a2b_base64(sr.text).decode()
         if sam == 'POST':
@@ -215,7 +354,7 @@ if __name__ == "__main__":
     # spawn WebKit view to do SAML interactive login
     if args.verbose:
         print("Got SAML %s, opening browser..." % sam, file=stderr)
-    slv = SAMLLoginView(uri, html, verbose=args.verbose, cookies=args.cookies, verify=args.verify)
+    slv = SAMLLoginView(uri, html, verbose=args.verbose, cookies=args.cookies, verify=args.verify, user_agent=args.user_agent)
     Gtk.main()
     if slv.closed:
         print("Login window closed by user.", file=stderr)
@@ -226,26 +365,76 @@ if __name__ == "__main__":
     # extract response and convert to OpenConnect command-line
     un = slv.saml_result.get('saml-username')
     server = slv.saml_result.get('server', args.server)
-    for cn in ('prelogin-cookie', 'portal-userauthcookie'):
+
+    for cn, ifh in (('prelogin-cookie','gateway'), ('portal-userauthcookie','portal')):
         cv = slv.saml_result.get(cn)
         if cv:
             break
     else:
-        cn = None
+        cn = ifh = None
+        p.error("Didn't get an expected cookie. Something went wrong.")
+
+    urlpath = args.interface + ":" + cn
+    openconnect_args = [
+        "--protocol=gp",
+        "--user="+un,
+        "--os="+args.ocos,
+        "--usergroup="+urlpath,
+        "--passwd-on-stdin",
+        server
+    ] + args.openconnect_extra
+
+    if args.insecure:
+        openconnect_args.insert(1, "--allow-insecure-crypto")
+    if args.user_agent:
+        openconnect_args.insert(1, "--useragent="+args.user_agent)
+    if args.cert:
+        cert, key = args.cert
+        if key:
+            openconnect_args.insert(1, "--sslkey="+key)
+        openconnect_args.insert(1, "--certificate="+cert)
+
+    openconnect_command = '''    echo {} |\n        sudo openconnect {}'''.format(
+        quote(cv), " ".join(map(quote, openconnect_args)))
 
-    fullpath = ('/global-protect/getconfig.esp' if args.portal else '/ssl-vpn/login.esp')
-    shortpath = ('portal' if args.portal else 'gateway')
     if args.verbose:
+        # Warn about ambiguities
+        if server != args.server and not args.uri:
+            print('''IMPORTANT: During the SAML auth, you were redirected from {0} to {1}. This probably '''
+                  '''means you should specify {1} as the server for final connection, but we're not 100% '''
+                  '''sure about this. You should probably try both.\n'''.format(args.server, server), file=stderr)
+        if ifh != args.interface and not args.uri:
+            print('''IMPORTANT: We started with SAML auth to the {} interface, but received a cookie '''
+                  '''that's often associated with the {} interface. You should probably try both.\n'''.format(args.interface, ifh),
+                  file=stderr)
         print('''\nSAML response converted to OpenConnect command line invocation:\n''', file=stderr)
-        print('''    echo {} |\n        openconnect --protocol=gp --user={} --usergroup={}:{} --passwd-on-stdin {}'''.format(
-            quote(cv), quote(un), quote(shortpath), quote(cn), quote(server)), file=stderr)
+        print(openconnect_command, file=stderr)
 
         print('''\nSAML response converted to test-globalprotect-login.py invocation:\n''', file=stderr)
-        print('''    test-globalprotect-login.py --user={} -p '' \\\n         https://{}{} {}={}\n'''.format(
-            quote(un), quote(server), quote(fullpath), quote(cn), quote(cv)), file=stderr)
-
-    varvals = {
-        'HOST': quote('https://%s/%s:%s' % (server, shortpath, cn)),
-        'USER': quote(un), 'COOKIE': quote(cv),
-    }
-    print('\n'.join('%s=%s' % pair for pair in varvals.items()))
+        print('''    test-globalprotect-login.py --user={} --clientos={} -p '' \\\n         https://{}/{} {}={}\n'''.format(
+            quote(un), quote(args.clientos), quote(server), quote(if2auth[args.interface]), quote(cn), quote(cv)), file=stderr)
+
+    if args.exec:
+        print('''Launching OpenConnect with {}, equivalent to:\n{}'''.format(args.exec, openconnect_command), file=stderr)
+        with tempfile.TemporaryFile('w+') as tf:
+            tf.write(cv)
+            tf.flush()
+            tf.seek(0)
+            # redirect stdin from this file, before it is closed by the context manager
+            # (it will remain accessible via the open file descriptor)
+            dup2(tf.fileno(), 0)
+        if args.exec == 'pkexec':
+            cmd = ["pkexec", "--user", "root", "openconnect"] + openconnect_args
+        elif args.exec == 'sudo':
+            cmd = ["sudo", "openconnect"] + openconnect_args
+        execvp(cmd[0], cmd)
+
+    else:
+        varvals = {
+            'HOST': quote('https://%s/%s' % (server, urlpath)),
+            'USER': quote(un), 'COOKIE': quote(cv), 'OS': quote(args.ocos),
+        }
+        print('\n'.join('%s=%s' % pair for pair in varvals.items()))
+
+if __name__ == "__main__":
+    main()