Re: sha1, sha2 functions into core?

On Fri, Aug 12, 2011 at 10:14:58PM +0300, Marko Kreen wrote:
> On Thu, Aug 11, 2011 at 5:46 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > Marko Kreen <markokr(at)gmail(dot)com> writes:
> >> On Wed, Aug 10, 2011 at 9:19 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >>> ... which this approach would create, because digest() isn't restricted
> >>> to just those algorithms.  I think it'd be better to just invent two
> >>> new functions, which also avoids issues for applications that currently
> >>> expect the digest functions to be installed in pgcrypto's schema.
> >
> >> I would suggest digest() with fixed list of algorithms: md5, sha1, sha2.
> >
> >> The uncommon/obsolete algorithms that can be used
> >> from digest() if compiled with openssl, are not something we
> >> need to worry over.  In fact we have never "supported" them,
> >> as no testing has been done.
> >
> > Hmm ... they may be untested by us, but I feel sure that if we remove
> > that functionality from pgcrypto, *somebody* is gonna complain.
>
> If you dont want to break digest() but do not want such behaviour in core,
> we could go with hash(data, algo) that has fixed number of digests,
> but also couple non-cryptographic hashes like crc32, lookup2/3.
> This would also fix the problem of people using hashtext() in user code.

Hmm, this thread seems to have petered out without a conclusion. Just
wanted to comment that there _are_ non-password storage uses for these
digests: I use them in a context of storing large files in a bytea
column, as a means to doing data deduplication, and avoiding pushing
files from clients to server and back.

Ross
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