postgresql/src/backend/libpq
Michael Paquier 1b73d0b1c3 Refactor code handling the names of files loaded in hba.c
This has the advantage to limit the presence of the GUC values
hba_file and ident_file to the code paths where these files are loaded,
easing the introduction of an upcoming feature aimed at adding inclusion
logic for files and directories in HBA and ident files.

Note that this needs the addition of the source file name to HbaLine, in
addition to the line number, which is something needed by the backend in
two places of auth.c (authentication failure details and auth_id log
when log_connections is enabled).

While on it, adjust a log generated on authentication failure to report
the name of the actual HBA file on which the connection attempt matched,
where the line number and the raw line written in the HBA file were
already included.  This was previously hardcoded as pg_hba.conf, which
would be incorrect when a custom value is used at postmaster startup for
the GUC hba_file.

Extracted from a larger patch by the same author.

Author: Julien Rouhaud
Discussion: https://postgr.es/m/20220223045959.35ipdsvbxcstrhya@jrouhaud
2022-10-26 11:42:13 +09:00
..
auth-sasl.c
auth-scram.c
auth.c Refactor code handling the names of files loaded in hba.c 2022-10-26 11:42:13 +09:00
be-fsstubs.c Prevent write operations on large objects in read-only transactions 2022-07-04 15:48:52 +09:00
be-gssapi-common.c
be-secure-common.c Remove misguided SSL key file ownership check in libpq. 2022-05-26 14:14:05 -04:00
be-secure-gssapi.c
be-secure-openssl.c Harmonize more parameter names in bulk. 2022-09-20 13:09:30 -07:00
be-secure.c Remove configure probe for netinet/tcp.h. 2022-08-18 16:31:11 +12:00
crypt.c
hba.c Refactor code handling the names of files loaded in hba.c 2022-10-26 11:42:13 +09:00
ifaddr.c Remove configure probe for sockaddr_in6 and require AF_INET6. 2022-08-26 10:18:30 +12:00
Makefile
meson.build meson: Add initial version of meson based build system 2022-09-21 22:37:17 -07:00
pg_hba.conf.sample
pg_ident.conf.sample
pqcomm.c Split up guc.c for better build speed and ease of maintenance. 2022-09-13 11:11:45 -04:00
pqformat.c
pqmq.c
pqsignal.c
README.SSL

src/backend/libpq/README.SSL

SSL
===

>From the servers perspective:


  Receives StartupPacket
           |
           |
 (Is SSL_NEGOTIATE_CODE?) -----------  Normal startup
           |                  No
           |
           | Yes
           |
           |
 (Server compiled with USE_SSL?) ------- Send 'N'
           |                       No        |
           |                                 |
           | Yes                         Normal startup
           |
           |
        Send 'S'
           |
           |
      Establish SSL
           |
           |
      Normal startup





>From the clients perspective (v6.6 client _with_ SSL):


      Connect
         |
         |
  Send packet with SSL_NEGOTIATE_CODE
         |
         |
  Receive single char  ------- 'S' -------- Establish SSL
         |                                       |
         | '<else>'                              |
         |                                  Normal startup
         |
         |
   Is it 'E' for error  ------------------- Retry connection
         |                  Yes             without SSL
         | No
         |
   Is it 'N' for normal ------------------- Normal startup
         |                  Yes
         |
   Fail with unknown

---------------------------------------------------------------------------

Ephemeral DH
============

Since the server static private key ($DataDir/server.key) will
normally be stored unencrypted so that the database backend can
restart automatically, it is important that we select an algorithm
that continues to provide confidentiality even if the attacker has the
server's private key.  Ephemeral DH (EDH) keys provide this and more
(Perfect Forward Secrecy aka PFS).

N.B., the static private key should still be protected to the largest
extent possible, to minimize the risk of impersonations.

Another benefit of EDH is that it allows the backend and clients to
use DSA keys.  DSA keys can only provide digital signatures, not
encryption, and are often acceptable in jurisdictions where RSA keys
are unacceptable.

The downside to EDH is that it makes it impossible to use ssldump(1)
if there's a problem establishing an SSL session.  In this case you'll
need to temporarily disable EDH (see initialize_dh()).