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Thread: pgcrypto: fix memory leak in openssl.c

pgcrypto: fix memory leak in openssl.c

From
"Marko Kreen"
Date:
pgcrypto crypt()/md5 and hmac() leak memory when compiled against
OpenSSL as openssl.c digest ->reset will do two DigestInit calls
against a context.  This happened to work with OpenSSL 0.9.6
but not with 0.9.7+.

Reason for the messy code was that I tried to avoid creating
wrapper structure to transport algorithm info and tried to use
OpenSSL context for it.  The fix is to create wrapper structure.

It also uses newer digest API to avoid memory allocations
on reset with newer OpenSSLs.

Attached are one patch for 7.3, 7.4, 8.0 branches and another
for 8.1 and HEAD.

Thanks to Daniel Blaisdell for reporting it.

--
marko
Attachment

Re: pgcrypto: fix memory leak in openssl.c

From
Neil Conway
Date:
On Sat, 2006-02-18 at 02:23 +0200, Marko Kreen wrote:
> Attached are one patch for 7.3, 7.4, 8.0 branches and another
> for 8.1 and HEAD.

Thanks, patches applied to the appropriate branches.

-Neil

Re: pgcrypto: fix memory leak in openssl.c

From
"Marko Kreen"
Date:
On 2/18/06, Marko Kreen <markokr@gmail.com> wrote:
> pgcrypto crypt()/md5 and hmac() leak memory when compiled against
> OpenSSL as openssl.c digest ->reset will do two DigestInit calls
> against a context.  This happened to work with OpenSSL 0.9.6
> but not with 0.9.7+.

Ugh, seems I read the old code slightly wrong.  The leak happens
also with regular digest(), although it will leak only 1 context
instance, not the 1000+ as the crypt-md5 does.  And on 8.1 there
is pgp_sym_encrypt that also does lots of resets on one context,
like crypt-md5.  In addition it does regular digest() in several
places.  So if compiled against OpenSSL, its leaking everywhere.

The positive side is that only 8.1 has openssl autoconfiguration,
older versions default to builtin algorithms that can be changed
only by editing Makefile, thus most packages are hopefully safe.

--
marko

Re: pgcrypto: fix memory leak in openssl.c

From
Tom Lane
Date:
"Marko Kreen" <markokr@gmail.com> writes:
> On 2/18/06, Marko Kreen <markokr@gmail.com> wrote:
>> pgcrypto crypt()/md5 and hmac() leak memory when compiled against
>> OpenSSL as openssl.c digest ->reset will do two DigestInit calls
>> against a context.  This happened to work with OpenSSL 0.9.6
>> but not with 0.9.7+.

> Ugh, seems I read the old code slightly wrong.  The leak happens
> also with regular digest(), although it will leak only 1 context
> instance, not the 1000+ as the crypt-md5 does.

I'm confused --- does this mean that the patch you sent recently
needs further work?

            regards, tom lane

Re: pgcrypto: fix memory leak in openssl.c

From
"Marko Kreen"
Date:
On 2/20/06, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> "Marko Kreen" <markokr@gmail.com> writes:
> > On 2/18/06, Marko Kreen <markokr@gmail.com> wrote:
> >> pgcrypto crypt()/md5 and hmac() leak memory when compiled against
> >> OpenSSL as openssl.c digest ->reset will do two DigestInit calls
> >> against a context.  This happened to work with OpenSSL 0.9.6
> >> but not with 0.9.7+.
>
> > Ugh, seems I read the old code slightly wrong.  The leak happens
> > also with regular digest(), although it will leak only 1 context
> > instance, not the 1000+ as the crypt-md5 does.
>
> I'm confused --- does this mean that the patch you sent recently
> needs further work?

No, it's fine.  As I did not 'fix' old code but replaced it.

It's just that I gave wrong answer to the question 'who is affected?'

--
marko