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Solaris has never bothered to add "const" to the second argument of PAM conversation procs, as all other Unixen did decades ago. This resulted in an "incompatible pointer" compiler warning when building --with-pam, but had no more serious effect than that, so we never did anything about it. However, as of GCC 14 the case is an error not warning by default. To complicate matters, recent OpenIndiana (and maybe illumos in general?) *does* supply the "const" by default, so we can't just assume that platforms using our solaris template need help. What we can do, short of building a configure-time probe, is to make solaris.h #define _PAM_LEGACY_NONCONST, which causes OpenIndiana's pam_appl.h to revert to the traditional definition, and hopefully will have no effect anywhere else. Then we can use that same symbol to control whether we include "const" in the declaration of pam_passwd_conv_proc(). Bug: #18995 Reported-by: Andrew Watkins <awatkins1966@gmail.com> Author: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/18995-82058da9ab4337a7@postgresql.org Backpatch-through: 13
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()).