Message-ID: <0f022354-c9cc-47c2-ace3-89d2101895f4@iki.fi>
Date: Mon, 8 Apr 2024 05:06:38 +0300
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Subject: Re: pgsql: Send ALPN in TLS handshake, require it in direct SSL
 connections
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To: Andres Freund <andres@anarazel.de>,
 Heikki Linnakangas <heikki.linnakangas@iki.fi>
Cc: pgsql-committers@lists.postgresql.org
References: <E1rtdlT-001387-J3@gemulon.postgresql.org>
 <20240408015055.xsuahullywpfwyvu@awork3.anarazel.de>
From: Heikki Linnakangas <hlinnaka@iki.fi>
In-Reply-To: <20240408015055.xsuahullywpfwyvu@awork3.anarazel.de>
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On 08/04/2024 04:50, Andres Freund wrote:
> On 2024-04-08 01:25:40 +0000, Heikki Linnakangas wrote:
>> Send ALPN in TLS handshake, require it in direct SSL connections
>>
>> libpq now always tries to send ALPN. With the traditional negotiated
>> SSL connections, the server accepts the ALPN, and refuses the
>> connection if it's not what we expect, but connecting without ALPN is
>> still OK. With the new direct SSL connections, ALPN is mandatory.
>>
>> NOTE: This uses "TBD-pgsql" as the protocol ID. We must register a
>> proper one with IANA before the release!
>>
>> Author: Greg Stark, Heikki Linnakangas
>> Reviewed-by: Matthias van de Meent, Jacob Champion
> 
> My compiler complains:
> 
> [396/992 42  39%] Compiling C object src/backend/postgres_lib.a.p/libpq_be-secure-openssl.c.o
> ../../../../../home/andres/src/postgresql/src/backend/libpq/be-secure-openssl.c: In function 'alpn_cb':
> ../../../../../home/andres/src/postgresql/src/backend/libpq/be-secure-openssl.c:1327:69: warning: ordered comparison of pointer with integer zero [-Wextra]
>   1327 |         if (*out == NULL || *outlen > sizeof(alpn_protos) || outlen <= 0)
>        |                                                                     ^~
> [991/992 1  99%] Linking target src/bin/pg_dump/pg_dump
> 
> And I think it may show why the warning is a good idea - I assume
> "*outlen <= 0" was intended?

Yes. Fixed, thanks!

-- 
Heikki Linnakangas
Neon (https://neon.tech)