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Difference between revisions of "SecureClientConnections"

 
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= Securing [[OpenStack]] Client Connections =
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<<[[TableOfContents]]()>>
 
<<[[TableOfContents]]()>>
  
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= Securing [[OpenStack]] Client Connections =
 
 
The  [[OpenStack]] client repositories (or packages) include both the Python API  bindings and the reference command line interface (CLI) implementation  to communicate with the [[OpenStack]] APIs.  Client support for modern  encrypted connections, i.e SSLv3 and/or TLSv1, has been spotty at best.Most  of the clients are capable of using SSL for encryption but often the  certificate verification part of the protocol did not work properly for  tier-2 or privately signed certificates, prompting the addition of the  --insecure option to some of the clients.  In addition, most of the  clients had no mechanism to specify an alternate CA bundle file to  enable certificate verification.Python  has historically had incomplete X.509 certificate support in its  standard library.  For example, ssl and httplib do not verify the  hostname as part of certificate verification. Four of the clients  (keystone, nova, cinder, quantum) use httplib2 which had no hostname  verification before 0.7.0 and what it currently has is incomplete. The  other two clients (glance and swift) use httplib directly and either  have no hostname verification (swift) or implement it locally (glance).
 
The  [[OpenStack]] client repositories (or packages) include both the Python API  bindings and the reference command line interface (CLI) implementation  to communicate with the [[OpenStack]] APIs.  Client support for modern  encrypted connections, i.e SSLv3 and/or TLSv1, has been spotty at best.Most  of the clients are capable of using SSL for encryption but often the  certificate verification part of the protocol did not work properly for  tier-2 or privately signed certificates, prompting the addition of the  --insecure option to some of the clients.  In addition, most of the  clients had no mechanism to specify an alternate CA bundle file to  enable certificate verification.Python  has historically had incomplete X.509 certificate support in its  standard library.  For example, ssl and httplib do not verify the  hostname as part of certificate verification. Four of the clients  (keystone, nova, cinder, quantum) use httplib2 which had no hostname  verification before 0.7.0 and what it currently has is incomplete. The  other two clients (glance and swift) use httplib directly and either  have no hostname verification (swift) or implement it locally (glance).
  
 
== Issue Summary ==
 
== Issue Summary ==
−
* Python's ssl module does no certificate hostname verification in 2.7.x;  it has been added in 3.2 but will not be backported.[1]* ssl is pinned to using protocol version SSLv23 and must be directly patched to override it.* httplib uses ssl and adds no hostname verification.  In addition it  only uses the default SSLV23 protocol version set by ssl.  We don't want  this as SSLv2 is deprecated and insecure.  Patching that value directly  into the ssl module works but is suboptimal.* httplib2 implements a basic hostname verification but it has some  problems such as only checking commonName if the certificate's  subjectAltNames is not present and handling wildcards differently than  specified in RFC-2818.* httplib2 uses an internal ca bundle (cacert.txt) if the ca_certs  argument is not given to HTTPSConnectionWithTimeout.<u>init</u>().* In other news, httplib2 only supports 3xx redirects for GET method.
+
* Python's ssl module does no certificate hostname verification in 2.7.x;  it has been added in 3.2 but will not be backported.[1]
 +
* ssl is pinned to using protocol version SSLv23 and must be directly patched to override it.
 +
* httplib uses ssl and adds no hostname verification.  In addition it  only uses the default SSLV23 protocol version set by ssl.  We don't want  this as SSLv2 is deprecated and insecure.  Patching that value directly  into the ssl module works but is suboptimal.
 +
* httplib2 implements a basic hostname verification but it has some  problems such as only checking commonName if the certificate's  subjectAltNames is not present and handling wildcards differently than  specified in RFC-2818.
 +
* httplib2 uses an internal ca bundle (cacert.txt) if the ca_certs  argument is not given to HTTPSConnectionWithTimeout.<u>init</u>().* In other news, httplib2 only supports 3xx redirects for GET method.
  
−
== Additional Notes ==
+
=== Additional Notes ===
 
glanceclient  has patched the ssl module out of httplib in favor of pyOpenSSL.  Stuart [[McLaren]] added http.VerifiedHTTPSConnection.host_matches_cert() to  validate commonName and subjectAltName for httplib connections but it  doesn't handle wildcards.
 
glanceclient  has patched the ssl module out of httplib in favor of pyOpenSSL.  Stuart [[McLaren]] added http.VerifiedHTTPSConnection.host_matches_cert() to  validate commonName and subjectAltName for httplib connections but it  doesn't handle wildcards.
  
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=== Why requests? [2] ===
+
== The CLI Solution ==
 +
The  current round of patches to the CLIs is to get them all up to the same  level of support for TLSv1 for authentication, at a minimum.  Glance and  Swift continue to use httplib directly for their data transfer  connections (really, all connections to their respective services) and  these already support SSL.v?.
 +
 
 +
== Why requests? [2] ==
 
The  requests module backported match_hostname() from Python 3.2.  Like all  of the other modules here it does not handle the iPAddress attribute in  subjectAltName. This is mostly relevant in development and testing use  cases like with [[DevStack]].  The 3.2 match_hostname() implementation  however does allow IP addresses as a dNSName.Requests  also brings a number of other features to the table that may or may not  have been implemented individually in the existing clients such as JSON  encoding/decoding and 3xx redirection support for POST, PUT, PATCH  DELETE, and HEAD.  Plus it is stable (notwithstanding the recent 1.0  release) and the developer is known in the OS community.
 
The  requests module backported match_hostname() from Python 3.2.  Like all  of the other modules here it does not handle the iPAddress attribute in  subjectAltName. This is mostly relevant in development and testing use  cases like with [[DevStack]].  The 3.2 match_hostname() implementation  however does allow IP addresses as a dNSName.Requests  also brings a number of other features to the table that may or may not  have been implemented individually in the existing clients such as JSON  encoding/decoding and 3xx redirection support for POST, PUT, PATCH  DELETE, and HEAD.  Plus it is stable (notwithstanding the recent 1.0  release) and the developer is known in the OS community.
−
 
−
=== The CLI Solution ===
 
−
The  current round of patches to the CLIs is to get them all up to the same  level of support for TLSv1 for authentication, at a minimum.  Glance and  Swift continue to use httplib directly for their data transfer  connections (really, all connections to their respective services) and  these already support SSL.v?.
 
  
 
=== Original Client HTTP Modules ===
 
=== Original Client HTTP Modules ===

Revision as of 13:58, 21 December 2012

Securing OpenStack Client Connections

<<TableOfContents()>>

The OpenStack client repositories (or packages) include both the Python API bindings and the reference command line interface (CLI) implementation to communicate with the OpenStack APIs. Client support for modern encrypted connections, i.e SSLv3 and/or TLSv1, has been spotty at best.Most of the clients are capable of using SSL for encryption but often the certificate verification part of the protocol did not work properly for tier-2 or privately signed certificates, prompting the addition of the --insecure option to some of the clients. In addition, most of the clients had no mechanism to specify an alternate CA bundle file to enable certificate verification.Python has historically had incomplete X.509 certificate support in its standard library. For example, ssl and httplib do not verify the hostname as part of certificate verification. Four of the clients (keystone, nova, cinder, quantum) use httplib2 which had no hostname verification before 0.7.0 and what it currently has is incomplete. The other two clients (glance and swift) use httplib directly and either have no hostname verification (swift) or implement it locally (glance).

Issue Summary

  • Python's ssl module does no certificate hostname verification in 2.7.x; it has been added in 3.2 but will not be backported.[1]
  • ssl is pinned to using protocol version SSLv23 and must be directly patched to override it.
  • httplib uses ssl and adds no hostname verification. In addition it only uses the default SSLV23 protocol version set by ssl. We don't want this as SSLv2 is deprecated and insecure. Patching that value directly into the ssl module works but is suboptimal.
  • httplib2 implements a basic hostname verification but it has some problems such as only checking commonName if the certificate's subjectAltNames is not present and handling wildcards differently than specified in RFC-2818.
  • httplib2 uses an internal ca bundle (cacert.txt) if the ca_certs argument is not given to HTTPSConnectionWithTimeout.init().* In other news, httplib2 only supports 3xx redirects for GET method.

Additional Notes

glanceclient has patched the ssl module out of httplib in favor of pyOpenSSL. Stuart McLaren added http.VerifiedHTTPSConnection.host_matches_cert() to validate commonName and subjectAltName for httplib connections but it doesn't handle wildcards.

The CLI Solution

The current round of patches to the CLIs is to get them all up to the same level of support for TLSv1 for authentication, at a minimum. Glance and Swift continue to use httplib directly for their data transfer connections (really, all connections to their respective services) and these already support SSL.v?.

Why requests? [2]

The requests module backported match_hostname() from Python 3.2. Like all of the other modules here it does not handle the iPAddress attribute in subjectAltName. This is mostly relevant in development and testing use cases like with DevStack. The 3.2 match_hostname() implementation however does allow IP addresses as a dNSName.Requests also brings a number of other features to the table that may or may not have been implemented individually in the existing clients such as JSON encoding/decoding and 3xx redirection support for POST, PUT, PATCH DELETE, and HEAD. Plus it is stable (notwithstanding the recent 1.0 release) and the developer is known in the OS community.

Original Client HTTP Modules

Client Module Client object CLI Arg
keystone httplib2 class.HTTPClient(httplib2.Http) --os-cacert
nova httplib2 class.HTTPClient(httplib2.Http) n/a
cinder httplib2 class.HTTPClient(httplib2.Http) n/a
glance httplib class.HTTPClient(object) --ca-file
swift httplib class.HTTPClient(object) n/a
quantum httplib2 class.HTTPClient(httplib2.Http) n/a

The approach taken for the httplib2 subclasses is to change the parent class to object and reqork the request() method to call requests.request(). Some of the differences for requests leaked out of that method but have been mostly containd within the HTTPClient class. All four of the clients (formetly) using httplib2 have implemented one or more features that can easily be handled by requests (redirection) or should also be propogated to the other clients. This is ripe for a refactor of HTTPClient to a common module but that effort is not in scope here.keystoneclient (complete) https://review.openstack.org/#/c/17624/ * replace httplib2 with requests

novaclient (complete) https://review.openstack.org/#/c/18257/ * replace httplib2 with requests

  • add --os-cacert and OS_CACERT support
  • provide ca_cert to keystone clinet for authentication

cinderclient (complete) https://review.openstack.org/#/c/18278/ * replace httplib2 with requests

  • add --os-cacert and OS_CACERT support
  • provide ca_cert to keystone clinet for authentication

glanceclient (complete) https://review.openstack.org/#/c/17698/ * rename --ca-cert to --os-cacert and add OS_CACERT

  • provide ca_cert to keystone client for authentication

swiftclient (complete) https://review.openstack.org/#/c/18393/ * add --os-cacert and OS_CACERT support

  • provide ca_cert to keystone client for authentication

quantumclient (not started) * replace httplib2 with requests

  • add --os-cacert and OS_CACERT support
  • provide ca_cert to keystone clinet for authentication

Testing

Aside from the usual unit tests, support for a TLS proxy is being added to DevStack to demonstrate and test a TLS-enabled OpenStack configuration. It uses stud as the TLS endpoint that proxies to the usual service endpoints. The most interesting challenge here is doing it all on a single host and making the service catalog work. Yay!The TLS-in-DevStack also builds a two-tiered CA (root and intermediate) for testing proper certificate chain validation.

Links

Retrieved from "https://wiki.openstack.org/w/index.php?title=SecureClientConnections&oldid=15245"