Allow to login to google using the browser

README.rst

@@ -57,6 +57,21 @@ You can find the ``GOOGLE_IDP_ID``, again from the admin console, via
 string like ``https://accounts.google.com/o/saml2/idp?idpid=aBcD01AbC``
 where the last bit (after the ``=``) is the IDP ID.
 
+Browser Login
+~~~~~~~~~~~~~~
+
+To enable browser based login, you will need to host the redirect server
+somewhere, for example
+
+.. code:: shell
+
+    gcloud run deploy --image cevoaustralia/aws-google-auth --args=--redirect-server --platform managed
+
+Then change your SAML settings so the ``ACS URL`` points to the redirect server.
+
+You will also need to change the Trust Relationship of your IAM Role to allow ``SAML:aud``
+to be the host of your redirect server.
+
 Installation
 ------------
 
@@ -114,47 +129,48 @@ Usage
 .. code:: shell
 
     $ aws-google-auth -h
-    usage: aws-google-auth [-h] [-u USERNAME] [-I IDP_ID] [-S SP_ID] [-R REGION]
-                           [-d DURATION] [-p PROFILE] [-D] [-q]
-                           [--bg-response BG_RESPONSE]
-                           [--saml-assertion SAML_ASSERTION] [--no-cache]
-                           [--print-creds] [--resolve-aliases]
-                           [--save-failure-html] [--save-saml-flow] [-a | -r ROLE_ARN] [-k]
-                           [-l {debug,info,warn}] [-V]
+    usage: aws-google-auth [-h] [-u USERNAME | -b | --redirect-server] [-I IDP_ID] [-S SP_ID] [-R REGION]
+                       [-d DURATION | --auto-duration] [-p PROFILE] [-A ACCOUNT] [-D] [-q] [--bg-response BG_RESPONSE]
+                       [--saml-assertion SAML_ASSERTION] [--no-cache] [--print-creds] [--resolve-aliases]
+                       [--save-failure-html] [--save-saml-flow] [--port PORT] [-a | -r ROLE_ARN] [-k]
+                       [-l {debug,info,warn}] [-V]
 
     Acquire temporary AWS credentials via Google SSO
 
     optional arguments:
       -h, --help            show this help message and exit
       -u USERNAME, --username USERNAME
                             Google Apps username ($GOOGLE_USERNAME)
+      -b, --browser         Google login in the browser (Requires SAML redirect server)
+      --redirect-server     Run the redirect server on port ($PORT)
       -I IDP_ID, --idp-id IDP_ID
                             Google SSO IDP identifier ($GOOGLE_IDP_ID)
       -S SP_ID, --sp-id SP_ID
                             Google SSO SP identifier ($GOOGLE_SP_ID)
       -R REGION, --region REGION
                             AWS region endpoint ($AWS_DEFAULT_REGION)
       -d DURATION, --duration DURATION
-                            Credential duration (defaults to value of $DURATION, then
-                            falls back to 43200)
+                            Credential duration in seconds (defaults to value of $DURATION, then falls back to 43200)
+      --auto-duration       Tries to use the longest allowed duration ($AUTO_DURATION)
       -p PROFILE, --profile PROFILE
-                            AWS profile (defaults to value of $AWS_PROFILE, then
-                            falls back to 'sts')
+                            AWS profile (defaults to value of $AWS_PROFILE, then falls back to 'sts')
+      -A ACCOUNT, --account ACCOUNT
+                            Filter for specific AWS account.
       -D, --disable-u2f     Disable U2F functionality.
       -q, --quiet           Quiet output
       --bg-response BG_RESPONSE
-                            Override default bgresponse challenge token ($GOOGLE_BG_RESPONSE).
+                            Override default bgresponse challenge token.
       --saml-assertion SAML_ASSERTION
                             Base64 encoded SAML assertion to use.
       --no-cache            Do not cache the SAML Assertion.
       --print-creds         Print Credentials.
       --resolve-aliases     Resolve AWS account aliases.
-      --save-failure-html   Write HTML failure responses to file for
-                            troubleshooting.
+      --save-failure-html   Write HTML failure responses to file for troubleshooting.
       --save-saml-flow      Write all GET and PUT requests and HTML responses to/from Google to files for troubleshooting.
+      --port PORT           Port for the redirect server ($PORT)
       -a, --ask-role        Set true to always pick the role
       -r ROLE_ARN, --role-arn ROLE_ARN
-                            The ARN of the role to assume ($AWS_ROLE_ARN)
+                            The ARN of the role to assume
       -k, --keyring         Use keyring for storing the password.
       -l {debug,info,warn}, --log {debug,info,warn}
                             Select log level (default: warn)

aws_google_auth/__init__.py

@@ -24,7 +24,10 @@ def parse_args(args):
         description="Acquire temporary AWS credentials via Google SSO",
     )
 
-    parser.add_argument('-u', '--username', help='Google Apps username ($GOOGLE_USERNAME)')
+    google_group = parser.add_mutually_exclusive_group()
+    google_group.add_argument('-u', '--username', help='Google Apps username ($GOOGLE_USERNAME)')
+    google_group.add_argument('-b', '--browser', action='store_true', help='Google login in the browser (Requires SAML redirect server)')
+    google_group.add_argument('--redirect-server', action='store_true', help='Run the redirect server on port ($PORT)')
     parser.add_argument('-I', '--idp-id', help='Google SSO IDP identifier ($GOOGLE_IDP_ID)')
     parser.add_argument('-S', '--sp-id', help='Google SSO SP identifier ($GOOGLE_SP_ID)')
     parser.add_argument('-R', '--region', help='AWS region endpoint ($AWS_DEFAULT_REGION)')
@@ -42,6 +45,7 @@ def parse_args(args):
     parser.add_argument('--resolve-aliases', action='store_true', help='Resolve AWS account aliases.')
     parser.add_argument('--save-failure-html', action='store_true', help='Write HTML failure responses to file for troubleshooting.')
     parser.add_argument('--save-saml-flow', action='store_true', help='Write all GET and PUT requests and HTML responses to/from Google to files for troubleshooting.')
+    parser.add_argument('--port', type=int, help='Port for the redirect server ($PORT)')
 
     role_group = parser.add_mutually_exclusive_group()
     role_group.add_argument('-a', '--ask-role', action='store_true', help='Set true to always pick the role')
@@ -160,6 +164,11 @@ def resolve_config(args):
         os.getenv('RESOLVE_AWS_ALIASES'),
         config.resolve_aliases)
 
+    config.browser = coalesce(
+        args.browser,
+        os.getenv('GOOGLE_BROWSER'),
+        config.browser)
+
     # Username (Option priority = ARGS, ENV_VAR, DEFAULT)
     config.username = coalesce(
         args.username,
@@ -190,13 +199,23 @@ def resolve_config(args):
         os.getenv('GOOGLE_BG_RESPONSE'),
         config.bg_response)
 
+    config.port = int(coalesce(
+        args.port,
+        os.getenv('PORT'),
+        config.port))
+
     return config
 
 
 def process_auth(args, config):
     # Set up logging
     logging.getLogger().setLevel(getattr(logging, args.log_level.upper(), None))
 
+    if args.redirect_server:
+        from aws_google_auth.redirect_server import start_redirect_server
+        start_redirect_server(config.port)
+        return
+
     if config.region is None:
         config.region = util.Util.get_input("AWS Region: ")
         logging.debug('%s: region is: %s', __name__, config.region)
@@ -211,6 +230,9 @@ def process_auth(args, config):
     elif args.saml_cache and config.saml_cache:
         saml_xml = config.saml_cache
         logging.info('%s: SAML cache found', __name__)
+    elif config.browser:
+        google_client = google.Google(config, save_failure=args.save_failure_html, save_flow=args.save_saml_flow)
+        saml_xml = google_client.do_browser_saml()
     else:
         # No cache, continue without.
         logging.info('%s: SAML cache not found', __name__)

aws_google_auth/configuration.py

@@ -39,6 +39,8 @@ def __init__(self, **kwargs):
         self.quiet = False
         self.bg_response = None
         self.account = ""
+        self.browser = False
+        self.port = 8000
 
     # For the "~/.aws/config" file, we use the format "[profile testing]"
     # for the 'testing' profile. The credential file will just be "[testing]"
@@ -146,6 +148,9 @@ def raise_if_invalid(self):
         # account
         assert (self.account.__class__ is str), "Expected account to be string. Got {}".format(self.account.__class__)
 
+        # port
+        assert (self.port.__class__ is int), "Expected port to be an integer. Got {}.".format(self.port.__class__)
+
     # Write the configuration (and credentials) out to disk. This allows for
     # regular AWS tooling (aws cli and boto) to use the credentials in the
     # profile the user specified.
@@ -173,6 +178,7 @@ def write(self, amazon_object):
             config_parser.set(profile, 'google_config.u2f_disabled', self.u2f_disabled)
             config_parser.set(profile, 'google_config.google_username', self.username)
             config_parser.set(profile, 'google_config.bg_response', self.bg_response)
+            config_parser.set(profile, 'google_config.browser', self.browser)
 
             with open(self.config_file, 'w+') as f:
                 config_parser.write(f)
@@ -271,6 +277,10 @@ def read(self, profile):
             read_account = unicode_to_string(config_parser[profile_string].get('account', None))
             self.account = coalesce(read_account, self.account)
 
+            # Browser
+            read_browser = config_parser[profile_string].getboolean('google_config.browser', None)
+            self.browser = coalesce(read_browser, self.browser)
+
         # SAML Cache
         try:
             with open(self.saml_cache_file, 'r') as f:

aws_google_auth/google.py

@@ -9,6 +9,7 @@
 import os
 import re
 import sys
+import webbrowser
 
 import requests
 from PIL import Image
@@ -20,6 +21,7 @@
 from six.moves import urllib_parse, input
 
 from aws_google_auth import _version
+from aws_google_auth.login_server import LoginServerHandler, LoginServer
 
 # The U2F USB Library is optional, if it's there, include it.
 try:
@@ -59,6 +61,23 @@ def __init__(self, config, save_failure, save_flow=False):
             self.save_flow_dir = "aws-google-auth-" + datetime.now().strftime('%Y-%m-%dT%H%M%S')
             os.makedirs(self.save_flow_dir, exist_ok=True)
 
+    def do_browser_saml(self):
+        logging.info('Opening url %s', self.login_url)
+        webbrowser.open(self.login_url)
+        saml_text = self._catch_saml()
+
+        return base64.b64decode(saml_text)
+
+    @staticmethod
+    def _catch_saml(port=4589):
+        server_address = ('', port)
+        httpd = LoginServer(server_address, LoginServerHandler)
+        logging.info('Starting http handler...\n')
+        httpd.handle_request()
+
+        assert ("SAMLResponse" in httpd.post_data), "Expected post data to contain SAMLResponse."
+        return httpd.post_data["SAMLResponse"][0]
+
     @property
     def login_url(self):
         return self.base_url + "/o/saml2/initsso?idpid={}&spid={}&forceauthn=false".format(

aws_google_auth/login_server.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+"""
+This HTTP server for capturing the SAMLResponse that is redirected to 127.0.0.1
+"""
+
+from http.server import BaseHTTPRequestHandler, HTTPServer
+import logging
+
+from aws_google_auth import util
+
+class LoginServer(HTTPServer):
+    post_data = {}
+
+
+class LoginServerHandler(BaseHTTPRequestHandler):
+    def _set_response(self):
+        self.send_response(200)
+        self.send_header('content-type', 'text/html')
+        self.end_headers()
+        self.wfile.write("""
+           <html>
+           <head><title>Success</title></head>
+           <body>
+           Check your console
+           <script>window.close()</script>
+           </body>
+           </html>
+        """.encode("utf-8"))
+
+    def do_POST(self):
+        self.server.post_data = util.Util.parse_post(self)
+        logging.debug("POST request,\nPath: %s\nHeaders:\n%s\n\nBody:\n%s\n",
+                str(self.path), str(self.headers), self.server.post_data)
+
+        self._set_response()

aws_google_auth/redirect_server.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python
+"""
+This HTTP server can be run on a server, and redirects the SAMLResponse to 127.0.0.1 so the command can capture it
+"""
+
+from http.server import BaseHTTPRequestHandler, HTTPServer
+import logging
+
+class RedirectServerHandler(BaseHTTPRequestHandler):
+    def do_POST(self):
+        self.send_response(307)
+        self.send_header('location', 'http://127.0.0.1:4589/')
+        self.end_headers()
+
+def start_redirect_server(port):
+    logging.basicConfig(level=logging.INFO)
+    server_address = ('', port)
+    httpd = HTTPServer(server_address, RedirectServerHandler)
+    logging.info('Starting http redirect server on: %s', port)
+    try:
+        httpd.serve_forever()
+    except KeyboardInterrupt:
+        pass
+    httpd.server_close()
+    logging.info('Stopping http redirect server')

aws_google_auth/util.py

@@ -6,6 +6,8 @@
 import os
 import sys
 from collections import OrderedDict
+from urllib.parse import parse_qs
+from cgi import parse_header, parse_multipart
 
 from six.moves import input
 from tabulate import tabulate
@@ -100,3 +102,17 @@ def get_password(prompt):
             password = sys.stdin.readline()
             print("")
         return password
+
+    @staticmethod
+    def parse_post(handler):
+        if 'content-type' not in handler.headers:
+            return {}
+        ctype, pdict = parse_header(handler.headers['content-type'])
+        if ctype == 'multipart/form-data':
+            postvars = parse_multipart(handler.rfile, pdict)
+        elif ctype == 'application/x-www-form-urlencoded':
+            length = int(handler.headers['content-length'])
+            postvars = parse_qs(handler.rfile.read(length).decode('utf-8'), keep_blank_values=1)
+        else:
+            postvars = {}
+        return postvars