Let me put this in a slightly different (and probably fairly tactless)
context here, for those of us without an infosec background.
1) Per-keyspace authentication allows for accountability and access
control, at least at a rudimentary level. Without this, there are
several types of applications that it would be impossible to use
Cassandra for, due to data security restrictions. Not just
impractical, but probably illegal in some cases.
2) If you have an intrusion into your network or a malicious user
internally (yes, this happens), you're completely unprotected without
per-keyspace authentication.
3) Per-keyspace authentication is done once-per-session; if you use
connection pooling or persistent connections of any sort in your
application, this has virtually zero overhead.
4) It's REALLY bad infosec practice to have your data accessible by
anyone, anytime, with no restrictions, which is how Cassandra
currently operates. While good network and application security can
minimize the risks, at present, a typo or missed change in a cut and
paste can potentially damage your data, especially if you have CFs/
SCFs that have the same name in two keyspaces.
5) This is common practice, pretty much everywhere. Every SQL
database, and almost every NOSQL database employs some form of AAA
(Authentication, Authorization, and Accountability) functionality.
It's pretty much an expected feature, though the granularity varies
depending on the implementation. AAA isn't expensive, but it sure can
save your butt later (and/or help you prosecute that Evil Nasty
Person). It can also provide you with nifty "Unauthorized" exceptions
that let you know you forgot to change the keyspace in your
configuration and almost did a Really Bad Thing.
6) Your bosses will like it (and you) a lot better if they don't have
to ask you where your organization's data went.
Hope this helps drive the point home that authentication and
authorization (as proposed) has near-zero overhead and is actually
pretty bad (read: slightly horrifying to auditors and security people,
but really exciting for evil people and typo gremlins) to not have.
-Jon
On Nov 11, 2009, at 4:18 PM, Coe, Robin wrote:
Do you mean that users interacting with Cassandra through the CLI
should be restricted based on a security service? I agree.
However, I believe the more common case is to front the Cassandra
service with an application layer, as you would expose a relational
backend. For that kind of service, the application should control
the security.
Basically, a user request to Cassandra is not stateful; any request
should be able to perform a transaction against any node in the
cluster, using an appropriate consistency model for the request.
Requiring something like real time token synchronization across all
nodes in a cluster seems outside of Cassandra’s eventual
consistency model.
Securing the data is intrinsically application-specific. While I
could see adding a plugin that makes the CLI access point secured, I
would still want that to be made in a pluggable fashion, so it could
be swapped out with a custom implementation.
Of course, this is just my point of view, but I make it after having
written several security layers on J2EE apps over the years and none
of them have been the same. Besides that, I want the data layer to
be highly efficient and in my opinion, it isn’t the work of the data
service to impose security.
Robin.
From: Brandon Williams [mailto:[email protected]]
Sent: November 11, 2009 4:44 PM
To: [email protected]
Subject: Re: Re: bandwidth limiting Cassandra's replication and
access control
On Wed, Nov 11, 2009 at 9:40 AM, Coe, Robin <[email protected]>
wrote:
IMO, auth services should be left to the application layer that
interfaces to Cassandra and not built into Cassandra. In the
tutorial snippet included below, the access being granted is at the
codebase level, not the transaction level. Since users of Cassandra
will generally be fronted by a service layer, the java security
manager isn’t going to suffice. What this snippet could do, though,
and may be the rationale for the request, is to ensure that
unauthorized users cannot instantiate a new Cassandra server.
However, if a user has physical access to the machine on which
Cassandra is installed, they could easily bypass that layer of
security.
What if Cassandra IS the application you're exposing? Imagine a
large company that creates one large internal Cassandra deployment,
and has multiple departments it wants to create separate keyspaces
for. You can do that now, but there's nothing except a gentlemen's
agreement to prevent one department from trashing another
department's keyspace, and accidents do happen. You can front the
service with some kind of application layer, but then you have
another API to maintain, and you'll lose some performance this way.
-Brandon
