public inbox for [email protected]
help / color / mirror / Atom feedFrom: Adrian Vogelsgesang <[email protected]>
To: [email protected] <[email protected]>
Subject: Libpq: Fail connection attempt if server didn't request a password
Date: Fri, 15 Jan 2021 17:56:54 +0000
Message-ID: <BY5PR03MB4965271A9AE58B7367D1DB52A3A70@BY5PR03MB4965.namprd03.prod.outlook.com> (raw)
Dear Postgres community,
Today, I learned that in the Postgres protocol, the Postgres server first has to request a password from the client before libpq will send it.
In particular, this also means: if the server doesn’t request a password but simply accepts the connection, libpq will just establish the connection.
Is there some way to let libpq fail the connection attempt in such a case, i.e. if a password was provided but not requested from the server?
Can I, as the client, force the authentication used during creating a connection to be scram-sha-256?
Or can I at least disable MD5 and plain-text authentication on the client-side (which I both consider unsecure)?
You might ask: Why do I care to enforce the authentication mode on the client side? Two reasons:
1. To identify misconfigured server. In our use case, all servers should require a password. By failing hard and early, we can more easily find misconfigured servers
2. To establish some trust on the client-side that I am actually connected to the correct server. In scram-sha-256, the server also has to authenticate to the client. This would be a nice additional level of security. However, this is worthless if the client doesn’t enforce a scram-sha-256 authentication: A malicious server could simply accept the connection without asking for a password or use the MD5 method instead
Cheers,
Adrian
view thread (2+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected]
Subject: Re: Libpq: Fail connection attempt if server didn't request a password
In-Reply-To: <BY5PR03MB4965271A9AE58B7367D1DB52A3A70@BY5PR03MB4965.namprd03.prod.outlook.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox