Re: Password identifiers, protocol aging and SCRAM protocol

On Wed, Sep 28, 2016 at 8:55 PM, Michael Paquier
<michael(dot)paquier(at)gmail(dot)com> wrote:
>> Our b64_encode routine does use whitespace, so we can't use it as is for
>> SCRAM. As the patch stands, we might never output anything long enough to
>> create linefeeds, but let's be tidy. The base64 implementation is about 100
>> lines of code, so perhaps we should just leave src/backend/utils/encode.c
>> alone, and make a new copy of the base64 routines in src/common.
>
> OK, I'll refresh that tomorrow with the rest. Thanks for the commit to
> extend password_encryption.

OK, so after more chatting with Heikki, here is a list of TODO items
and a summary of the state of things:
- base64 encoding routines should drop whitespace (' ', \r, \t), and
it would be better to just copy those from the backend's encode.c to
src/common/. No need to move escape and binary things, nor touch
backend's base64 routines.
- No need to move sha1.c to src/common/. Better to just get sha2.c
into src/common/ as we aim at SCRAM-SHA-256.
- random() called in the client is no good. We need something better here.
- The error handling needs to be reworked and should follow the
protocol presented by RFC5802, by sending back e= messages. This needs
a bit of work, not much I think though as the infra is in place in the
core patch.
- Let's discard the md5-or-scram optional thing in pg_hba.conf. This
complicates the error handling protocol.

I am marking this patch as returned with feedback for current CF and
will post a new set soon, moving it to the next CF once I have the new
set of patches ready for posting.
--
Michael