better SSL error handling (especially, distinguish cert from non-cert errors)

[nu-vpn-proxy.git] / gp-saml-gui.py

diff --git a/gp-saml-gui.py b/gp-saml-gui.py
index e34d1236f3145793ff8531aaf9f5868e52015f48..2d29d6204bc4c0d7bd2bce410ec6bbbd81eebbdb 100755 (executable)
--- a/gp-saml-gui.py
+++ b/gp-saml-gui.py
@@ -7,9 +7,11 @@ import urllib
 import requests
 import xml.etree.ElementTree as ET
 import os
 import requests
 import xml.etree.ElementTree as ET
 import os

+import ssl

 
 

+from shlex import quote

 from sys import stderr
 from sys import stderr

-from binascii import a2b_base64
+from binascii import a2b_base64, b2a_base64

 
 gi.require_version('Gtk', '3.0')
 from gi.repository import Gtk
 
 gi.require_version('Gtk', '3.0')
 from gi.repository import Gtk


@@ -18,15 +20,18 @@ gi.require_version('WebKit2', '4.0')
 from gi.repository import WebKit2
 
 class SAMLLoginView:
 from gi.repository import WebKit2
 
 class SAMLLoginView:

-    def __init__(self, uri, html=None, verbose=False, cookies=None):
+    def __init__(self, uri, html=None, verbose=False, cookies=None, verify=True):

         window = Gtk.Window()
 
         # API reference: https://lazka.github.io/pgi-docs/#WebKit2-4.0
 
         self.success = False
         window = Gtk.Window()
 
         # API reference: https://lazka.github.io/pgi-docs/#WebKit2-4.0
 
         self.success = False

+        self.saml_result = {}

         self.verbose = verbose
 
         self.ctx = WebKit2.WebContext.get_default()
         self.verbose = verbose
 
         self.ctx = WebKit2.WebContext.get_default()

+        if not args.verify:
+            self.ctx.set_tls_errors_policy(WebKit2.TLSErrorsPolicy.IGNORE)

         self.cookies = self.ctx.get_cookie_manager()
         if args.cookies:
             self.cookies.set_accept_policy(WebKit2.CookieAcceptPolicy.ALWAYS)
         self.cookies = self.ctx.get_cookie_manager()
         if args.cookies:
             self.cookies.set_accept_policy(WebKit2.CookieAcceptPolicy.ALWAYS)


@@ -65,16 +70,18 @@ class SAMLLoginView:
                 if (name.startswith('saml-') or name in ('prelogin-cookie', 'portal-userauthcookie')):
                     t.append((name, value))
             h.foreach(listify)
                 if (name.startswith('saml-') or name in ('prelogin-cookie', 'portal-userauthcookie')):
                     t.append((name, value))
             h.foreach(listify)

-            self.saml_result = d = dict(l)
-            if d:
-                if self.verbose:
-                    print("Got SAML relevant headers, done: %r" % d, file=stderr)
+            d = dict(l)
+            if d and self.verbose:
+                print("Got SAML result headers: %r" % d, file=stderr)
+            d = self.saml_result
+            d.update(dict(l))
+            if 'saml-username' in d and ('prelogin-cookie' in d or 'portal-userauthcookie' in d):
+                print("Got all required SAML headers, done.", file=stderr)

                 self.success = True
                 Gtk.main_quit()
 
 def parse_args(args = None):
     p = argparse.ArgumentParser()
                 self.success = True
                 Gtk.main_quit()
 
 def parse_args(args = None):
     p = argparse.ArgumentParser()

-    p.add_argument('-v','--verbose', default=0, action='count')

     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')
     p.add_argument('-C', '--no-cookies', dest='cookies', action='store_const', const=None,
     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')
     p.add_argument('-C', '--no-cookies', dest='cookies', action='store_const', const=None,


@@ -85,6 +92,10 @@ def parse_args(args = None):
     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('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)')
+    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)
 
     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)
 


@@ -112,24 +123,54 @@ if __name__ == "__main__":
     s.cert = args.cert
 
     # query prelogin.esp and parse SAML bits
     s.cert = args.cert
 
     # query prelogin.esp and parse SAML bits

-    endpoint = 'https://{}/{}/prelogin.esp'.format(args.server, ('global-protect' if args.portal else 'ssl-vpn'))
-    res = s.post(endpoint, verify=args.verify, data=args.extra)
-    xml = ET.fromstring(res.content)
-    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)")
-    elif sam.text == 'POST':
-        html, uri = a2b_base64(sr.text).decode(), None
-    elif sam.text == 'REDIRECT':
-        uri, html = sr.text, None
+    if args.uri:
+        sam, uri, html = 'URI', args.server, None

     else:
     else:

-        p.error("Unknown SAML method (%s)" % sam.text)
+        endpoint = 'https://{}/{}/prelogin.esp'.format(args.server, ('global-protect' if args.portal else 'ssl-vpn'))
+        print("Looking for SAML auth tags in response to %s..." % endpoint, file=stderr)
+        try:
+            res = s.post(endpoint, verify=args.verify, data=args.extra)
+        except Exception as ex:
+            rootex = ex
+            while True:
+                if isinstance(rootex, ssl.SSLError):
+                    break
+                elif not rootex.__cause__ and not rootex.__context__:
+                    break
+                rootex = rootex.__cause__ or rootex.__context__
+            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)
+            else:
+                raise
+        xml = ET.fromstring(res.content)
+        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)")
+        sam = sam.text
+        sr = a2b_base64(sr.text).decode()
+        if sam == 'POST':
+            html, uri = sr, None
+        elif sam == 'REDIRECT':
+            uri, html = sr, None
+        else:
+            p.error("Unknown SAML method (%s)" % sam)
+
+    # launch external browser for debugging
+    if args.external:
+        print("Got SAML %s, opening external browser for debugging..." % sam, file=stderr)
+        import webbrowser
+        if html:
+            uri = 'data:text/html;base64,' + b2a_base64(html.encode()).decode()
+        webbrowser.open(uri)
+        raise SystemExit

 
     # spawn WebKit view to do SAML interactive login
     if args.verbose:
 
     # spawn WebKit view to do SAML interactive login
     if args.verbose:

-        print("Got SAML POST, opening browser...", file=stderr)
-    slv = SAMLLoginView(uri, html, verbose=args.verbose, cookies=args.cookies)
+        print("Got SAML %s, opening browser..." % sam, file=stderr)
+    slv = SAMLLoginView(uri, html, verbose=args.verbose, cookies=args.cookies, verify=args.verify)

     Gtk.main()
     if not slv.success:
         p.error('''Login window closed without producing SAML cookie''')
     Gtk.main()
     if not slv.success:
         p.error('''Login window closed without producing SAML cookie''')


@@ -143,9 +184,15 @@ if __name__ == "__main__":
     else:
         cn = None
 
     else:
         cn = None
 

+    fullpath = ('/global-protect/getconfig.esp' if args.portal else '/ssl-vpn/login.esp')
+    shortpath = ('portal' if args.portal else 'gateway')

     if args.verbose:
         print('''\n\nSAML response converted to OpenConnect command line invocation:\n''', file=stderr)
     if args.verbose:
         print('''\n\nSAML response converted to OpenConnect command line invocation:\n''', file=stderr)

-        print('''    echo {!r} |\n        openconnect --protocol=gp --user={!r} --usergroup={}:{} --passwd-on-stdin {}\n'''.format(
-            cv, un, ('portal' if args.portal else 'gateway'), cn, args.server), file=stderr)
-
-    print("HOST={!r}\nUSER={!r}\nCOOKIE={!r}".format('https://%s/%s:%s' % (args.server, ('portal' if args.portal else 'gateway'), cn), un, cv))
+        print('''    echo {} |\n        openconnect --protocol=gp --user={} --usergroup={}:{} --passwd-on-stdin {}\n'''.format(
+            quote(cv), quote(un), quote(shortpath), quote(cn), quote(args.server)), file=stderr)
+
+    varvals = {
+        'HOST': quote('https://%s/%s:%s' % (args.server, shortpath, cn)),
+        'USER': quote(un), 'COOKIE': quote(cv),
+    }
+    print('\n'.join('%s=%s' % pair for pair in varvals.items()))