postgresql/src/backend/libpq
Michael Paquier d4781d8873 Refactor code related to pg_hba_file_rules() into new file
hba.c is growing big, and more contents are planned for it.  In order to
prepare for this future work, this commit moves all the code related to
the system function processing the contents of pg_hba.conf,
pg_hba_file_rules() to a new file called hbafuncs.c, which will be used
as the location for the SQL portion of the authentication file parsing.
While on it, HbaToken, the structure holding a string token lexed from a
configuration file related to authentication, is renamed to a more
generic AuthToken, as it gets used not only for pg_hba.conf, but also
for pg_ident.conf.  TokenizedLine is now named TokenizedAuthLine.

The size of hba.c is reduced by ~12%.

Author: Julien Rouhaud
Reviewed-by: Aleksander Alekseev, Michael Paquier
Discussion: https://postgr.es/m/20220223045959.35ipdsvbxcstrhya@jrouhaud
2022-03-24 12:42:30 +09:00
..
Makefile Refactor SASL code with a generic interface for its mechanisms 2021-07-07 10:55:15 +09:00
README.SSL Move EDH support to common files 2018-01-23 07:11:38 -05:00
auth-sasl.c Improve error handling of cryptohash computations 2022-01-11 09:55:16 +09:00
auth-scram.c Improve error handling of HMAC computations 2022-01-13 16:17:21 +09:00
auth.c Clean up messy API for src/port/thread.c. 2022-01-11 13:46:20 -05:00
be-fsstubs.c Update copyright for 2022 2022-01-07 19:04:57 -05:00
be-gssapi-common.c Update copyright for 2022 2022-01-07 19:04:57 -05:00
be-secure-common.c Allow root-owned SSL private keys in libpq, not only the backend. 2022-02-28 14:12:52 -05:00
be-secure-gssapi.c Update copyright for 2022 2022-01-07 19:04:57 -05:00
be-secure-openssl.c Update copyright for 2022 2022-01-07 19:04:57 -05:00
be-secure.c Update copyright for 2022 2022-01-07 19:04:57 -05:00
crypt.c Improve error handling of cryptohash computations 2022-01-11 09:55:16 +09:00
hba.c Refactor code related to pg_hba_file_rules() into new file 2022-03-24 12:42:30 +09:00
ifaddr.c Update copyright for 2022 2022-01-07 19:04:57 -05:00
pg_hba.conf.sample pg_hba.conf.sample: Reword connection type section 2021-04-29 07:00:20 +02:00
pg_ident.conf.sample Reformat the comments in pg_hba.conf and pg_ident.conf 2010-01-26 06:58:39 +00:00
pqcomm.c Revert "graceful shutdown" changes for Windows. 2022-03-22 10:19:15 -04:00
pqformat.c Update copyright for 2022 2022-01-07 19:04:57 -05:00
pqmq.c Update copyright for 2022 2022-01-07 19:04:57 -05:00
pqsignal.c Update copyright for 2022 2022-01-07 19:04:57 -05:00

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()).