Adds optional support for SSL server certificate validation

tests/s3/test_https_cert_validation.py

+# Copyright 2010 Google Inc.

[Mike Schwartz, 2011/04/19 23:49:13]

2011

[xtof.g, 2011/04/20 16:18:38]

Done.

+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish, dis-
+# tribute, sublicense, and/or sell copies of the Software, and to permit
+# persons to whom the Software is furnished to do so, subject to the fol-
+# lowing conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
+# ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+# SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,·
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+"""
+Tests to validate correct validation of SSL server certificates.
+
+Note that this test assumes two external dependencies are available:
+  - A http proxy, which by default is assumed to be at host 'cache' and port
+    3128.  This can be overridden with environment variables PROXY_HOST and
+    PROXY_PORT, respectively.
+  - An ssl-enabled web server that will return a valid certificate signed by one
+    of the bundled CAs, and which can be reached by an alternate hostname that
+    does not match the CN in that certificate.  By default, this test usees host

[Mike Schwartz, 2011/04/19 23:49:13]

uses

[xtof.g, 2011/04/20 16:18:38]

Done.

+    'www' (without fully qualified domain). This can be overridden with
+    environment variable INVALID_HOSTNAME_HOST. If no suitable host is already
+    available, such a mapping can be established by temporarily adding an IP
+    address for, say. www.google.com or www.amazon.com to /etc/hosts.

[Mike Schwartz, 2011/04/19 23:49:13]

say,

+"""
+
+import os
+import ssl
+import unittest
+
+import boto
+from boto import exception, https_connection
+from boto.gs.connection import GSConnection
+from boto.s3.connection import S3Connection
+
+# Other CA certs contains a valid CA certificate of a CA that is used by neither

[Mike Schwartz, 2011/04/19 23:49:13]

Do you mean "other_cacerts.txt" ?
If so it would be easier to parse this sentence if you use that instead. My
grammar eyeball is trying to figure out whether the current sentence should be
"certs contain" vs "cert contains"...

[xtof.g, 2011/04/20 16:18:38]

Thanks, fixed.

+# S3 nor Google Storage.  Validation against this CA cert should result in a
+# certificate error.
+DEFAULT_CA_CERTS_FILE = os.path.join(
+        os.path.dirname(os.path.abspath(__file__ )), 'other_cacerts.txt')
+
+
+PROXY_HOST = os.environ.get('PROXY_HOST', 'cache')
+PROXY_PORT = os.environ.get('PROXY_PORT', '3128')
+
+# This test assumes that this host returs a certificate signed by one of the

[Mike Schwartz, 2011/04/19 23:49:13]

returns

[xtof.g, 2011/04/20 16:18:38]

Thanks... Sorry -- I should have spell checked...

+# trusted CAs, but with a Common Name that won't match host name 'www' (i.e.,
+# the server should return a certificate with CN 'www.<somedomain>.com'.

[Mike Schwartz, 2011/04/19 23:49:13]

missing close paren

[xtof.g, 2011/04/20 16:18:38]

Done.

+INVALID_HOSTNAME_HOST = os.environ.get('INVALID_HOSTNAME_HOST', 'www')
+
+class CertValidationTest (unittest.TestCase):
+
+    def setUp(self):
+        # Clear config
+        for section in boto.config.sections():
+            boto.config.remove_section(section)
+
+        # Enable https_validate_certificates (which is not the default yet).

[Mike Schwartz, 2011/04/19 23:49:13]

any reason to include this parenthetical?
Even after it's the default I'd think you still want this setup, to make the
test not be brittle.

[xtof.g, 2011/04/20 16:18:38]

Good point, removed.

+        boto.config.add_section('Boto')
+        boto.config.setbool('Boto', 'https_validate_certificates', True)
+
+        # Set up bogus credentials so that the auth module is willing to go
+        # ahead and make a request; the request should fail with a service-level
+        # error if it does get to the service (S3 or GS).
+        boto.config.add_section('Credentials')
+        boto.config.set('Credentials', 'gs_access_key_id', 'xyz')
+        boto.config.set('Credentials', 'gs_secret_access_key', 'xyz')
+        boto.config.set('Credentials', 'aws_access_key_id', 'xyz')
+        boto.config.set('Credentials', 'aws_secret_access_key', 'xyz')
+
+    def enableProxy(self):
+        boto.config.set('Boto', 'proxy', PROXY_HOST)
+        boto.config.set('Boto', 'proxy_port', PROXY_PORT)
+
+    def assertConnectionThrows(self, connection_class, error):
+        conn = connection_class()
+        self.assertRaises(error, conn.get_all_buckets)
+
+    def do_test_valid_cert(self):
+        # When connecting to actual servers with bundled root certificates, no
+        # cert errors should be thrown; instead we will get "invalid
+        # credentials" errors since the config used does not contain any
+        # credentials.
+        self.assertConnectionThrows(S3Connection, exception.S3ResponseError)
+        self.assertConnectionThrows(GSConnection, exception.GSResponseError)
+
+    def test_valid_cert(self):
+        self.do_test_valid_cert()
+
+    def test_valid_cert_with_proxy(self):
+        self.enableProxy()
+        self.do_test_valid_cert()
+
+    def do_test_invalid_signature(self):
+        boto.config.set('Boto', 'ca_certificates_file', DEFAULT_CA_CERTS_FILE)
+        self.assertConnectionThrows(S3Connection, ssl.SSLError)
+        self.assertConnectionThrows(GSConnection, ssl.SSLError)
+
+    def test_invalid_signature(self):
+        self.do_test_invalid_signature()
+
+    def test_invalid_signature_with_proxy(self):
+        self.enableProxy()
+        self.do_test_invalid_signature()
+
+    def do_test_invalid_host(self):
+        boto.config.set('Credentials', 'gs_host', INVALID_HOSTNAME_HOST)
+        boto.config.set('Credentials', 's3_host', INVALID_HOSTNAME_HOST)
+        self.assertConnectionThrows(S3Connection, ssl.SSLError)
+        self.assertConnectionThrows(GSConnection, ssl.SSLError)
+
+    def do_test_invalid_host(self):
+        boto.config.set('Credentials', 'gs_host', INVALID_HOSTNAME_HOST)
+        boto.config.set('Credentials', 's3_host', INVALID_HOSTNAME_HOST)
+        self.assertConnectionThrows(
+                S3Connection, https_connection.InvalidCertificateException)
+        self.assertConnectionThrows(
+                GSConnection, https_connection.InvalidCertificateException)
+
+    def test_invalid_host(self):
+        self.do_test_invalid_host()
+
+    def test_invalid_host_with_proxy(self):
+        self.enableProxy()
+        self.do_test_invalid_host()
+