postgresql

History

Andrew Dunstan 896fcdb230 Provide a TLS init hook The default hook function sets the default password callback function. In order to allow preloaded libraries to have an opportunity to override the default, TLS initialization if now delayed slightly until after shared preloaded libraries have been loaded. A test module is provided which contains a trivial example that decodes an obfuscated password for an SSL certificate. Author: Andrew Dunstan Reviewed By: Andreas Karlsson, Asaba Takanori Discussion: https://postgr.es/m/04116472-818b-5859-1d74-3d995aab2252@2ndQuadrant.com		2020-03-25 17:13:17 -04:00
..
Makefile	Split all OBJS style lines in makefiles into one-line-per-entry style.	2019-11-05 14:41:07 -08:00
README.SSL	Move EDH support to common files	2018-01-23 07:11:38 -05:00
auth-scram.c	Remove excess parens in ereport() calls	2020-01-30 13:32:04 -03:00
auth.c	Clean up some code, comments and docs referring to Windows 2000 and older	2020-02-19 13:20:33 +09:00
be-fsstubs.c	Update copyrights for 2020	2020-01-01 12:21:45 -05:00
be-gssapi-common.c	Update copyrights for 2020	2020-01-01 12:21:45 -05:00
be-secure-common.c	Update copyrights for 2020	2020-01-01 12:21:45 -05:00
be-secure-gssapi.c	Extensive code review for GSSAPI encryption mechanism.	2020-01-11 17:14:08 -05:00
be-secure-openssl.c	Provide a TLS init hook	2020-03-25 17:13:17 -04:00
be-secure.c	Update copyrights for 2020	2020-01-01 12:21:45 -05:00
crypt.c	Update copyrights for 2020	2020-01-01 12:21:45 -05:00
hba.c	Introduce macros for typalign and typstorage constants.	2020-03-04 10:34:25 -05:00
ifaddr.c	Update copyrights for 2020	2020-01-01 12:21:45 -05:00
pg_hba.conf.sample	Rename "scram" to "scram-sha-256" in pg_hba.conf and password_encryption.	2017-04-18 14:50:50 +03:00
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	Assume that we have utime() and <utime.h>.	2020-02-21 14:30:47 -05:00
pqformat.c	Update copyrights for 2020	2020-01-01 12:21:45 -05:00
pqmq.c	Update copyrights for 2020	2020-01-01 12:21:45 -05:00
pqsignal.c	Update copyrights for 2020	2020-01-01 12:21:45 -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()).