Heikki Linnakangas wrote:

> I did again the refactoring you did back in 2006, patch attached.
> One thing I did differently: I moved the raw, non-encrypted,
> read/write functions to separate functions: pqsecure_raw_read and
> pqsecure_raw_write. Those functions encapsulate the SIGPIPE
> handling. The OpenSSL code implements a custom BIO, which calls to
> pqsecure_raw_read/write to do the low-level I/O.  Similarly in the
> server-side, there are be_tls_raw_read and pg_tls_raw_write
> functions, which do the
> prepare_for_client_read()/client_read_ended() dance, so that the SSL
> implementation doesn't need to know about that.

I'm skimming over this patch (0001).  There are some issues:

* You duplicated the long comment under the IDENTIFICATION tag that was
  in be-secure.c; it's now both in that file and also in
  be-secure-openssl.c.  I think it should be removed from be-secure.c.
  Also, the hardcoded DH params are duplicated in be-secure.c, but they
  belong in -openssl.c only now.

* There is some mixup regarding USE_SSL and USE_OPENSSL in be-secure.c.
  I think anything that's OpenSSL-specific should be in
  be-secure-openssl.c only; any new SSL implementation will need to
  implement all those functions.  For instance, be_tls_init().
  I imagine that if we select any SSL implementation, USE_SSL would get
  defined, and each SSL implementation would additionally define its own
  symbol.  Unless the idea is to get rid of USE_OPENSSL completely, and
  use only the Makefile bit to decide which implementation to use?  If
  so, then USE_OPENSSL as a preprocessor symbol is useless ...

* ssl_renegotiation_limit is also duplicated.  But removing this one is
  probably not going to be as easy as deleting a line from be-secure.c,
  because guc.c depends on that one.  I think that variable should be
  defined in be-secure.c (i.e. delete it from -openssl) and make sure
  that all SSL implementations enforce it on their own somehow.

The DISABLE_SIGPIPE thingy looks wrong in pqsecure_write.  I think it
should be like this:

ssize_t
pqsecure_write(PGconn *conn, const void *ptr, size_t len)
{
        ssize_t         n;

#ifdef USE_SSL
        if (conn->ssl_in_use)
        {
                DECLARE_SIGPIPE_INFO(spinfo);

                DISABLE_SIGPIPE(conn, spinfo, return -1);

                n = pgtls_write(conn, ptr, len);

                RESTORE_SIGPIPE(spinfo);
        }
        else 
#endif   /* USE_OPENSSL */
        {
                n = pqsecure_raw_write(conn, ptr, len);
        }

        return n;
}

You are missing the restore call, and I moved the declaration inside the
ssl_in_use block since otherwise it's not useful.  The other path is
fine since pqsecure_raw_write disables and restores the flag by itself.
Also, you're missing DECLARE/DISABLE/RESTORE in the ssl_in_use block in
pqsecure_read.  (The original code does not have that code in the
non-SSL path.  I assume, without checking, that that's okay.)  I also
assume without checking that all SSL implementations would be fine with
this SIGPIPE handling.

Another thing that seems wrong is the REMEMBER_EPIPE stuff.  The
fe-secure-openssl.c code should be setting the flag, but AFAICS only the
non-SSL code is doing it.


Thanks for working on this -- I'm sure many distributors will be happy
to be able to enable other, less license-broken TLS implementations.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services


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