Re: [Proposal] Table-level Transparent Data Encryption (TDE) and KeyManagement Service (KMS) - Mailing list pgsql-hackers

On 3/4/19 6:40 AM, Masahiko Sawada wrote:
> On Sat, Mar 2, 2019 at 5:27 AM Robert Haas <robertmhaas@gmail.com> wrote:
>>
>> On Thu, Feb 7, 2019 at 3:28 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>>> WAL encryption will follow as an additional feature.
>>
>> I don't think WAL encryption is an optional feature.  You can argue
>> about whether it's useful to encrypt the disk files in the first place
>> given that there's no privilege boundary between the OS user and the
>> database, but a lot of people seem to think it is and maybe they're
>> right.  However, who can justify encrypting only SOME of the disk
>> files and not others?  I mean, maybe you could justify not encryption
>> the SLRU files on the grounds that they probably don't leak much in
>> the way of interesting information, but the WAL files certainly do --
>> your data is there, just as much as in the data files themselves.
>>
> 
> Agreed.
> 
>> To be honest, I think there is a lot to like about the patches
>> Cybertec has proposed.  Those patches don't have all of the fancy
>> key-management stuff that you are proposing here, but maybe that
>> stuff, if we want it, could be added, rather than starting over from
>> scratch.  It seems to me that those patches get a lot of things right.
>> In particular, it looked to me when I looked at them like they made a
>> pretty determined effort to encrypt every byte that might go down to
>> the disk.  It seems to me that you if you want encryption, you want
>> that.
>>
> 
> Agreed. I think the patch lacks the key management stuff: 2-tier key
> architecture and integration of postgres with key management systems.
> I'd like to work together and can propose the patch of key management
> stuff to the proposed patch.
> 

Sounds like a plan. It'd be nice to come up with a unified version of
those two patches, combining the good pieces from both.

I wonder how other databases deal with key management? Surely we're not
the first/only database that tries to do transparent encryption, so
perhaps we could learn something from others? For example, do they use
this 2-tier key architecture? How do they do key management? etc.

I don't say we should copy from them, but it'd allow us to (a) avoid
making the same mistakes and (b) build a solution the users are already
somewhat familiar with.

May I suggest creating a page on the PostgreSQL wiki, explaining the
design and updating it as the discussion develops? It's rather difficult
to follow all the different sub-threads, and IIRC some larger patches
used that successfully for this purpose.

See for example:

* https://wiki.postgresql.org/wiki/Parallel_External_Sort
* https://wiki.postgresql.org/wiki/Parallel_Internal_Sort


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services