Don't share SSL_CTX between libpq connections.
There were several issues with the old coding:
1. There was a race condition, if two threads opened a connection at the
same time. We used a mutex around SSL_CTX_* calls, but that was not
enough, e.g. if one thread SSL_CTX_load_verify_locations() with one
path, and another thread set it with a different path, before the first
thread got to establish the connection.
2. Opening two different connections, with different sslrootcert settings,
seemed to fail outright with "SSL error: block type is not 01". Not sure
why.
3. We created the SSL object, before calling SSL_CTX_load_verify_locations
and SSL_CTX_use_certificate_chain_file on the SSL context. That was
wrong, because the options set on the SSL context are propagated to the
SSL object, when the SSL object is created. If they are set after the
SSL object has already been created, they won't take effect until the
next connection. (This is bug #14329)
At least some of these could've been fixed while still using a shared
context, but it would've been more complicated and error-prone. To keep
things simple, let's just use a separate SSL context for each connection,
and accept the overhead.
Backpatch to all supported versions.
Report, analysis and test case by Kacper Zuk.
Discussion: <20160920101051.1355.79453@wrigleys.postgresql.org>
Branch
------
REL9_6_STABLE
Details
-------
http://git.postgresql.org/pg/commitdiff/341acf235943c15aa56103ef7b66ecec625b4af0
Modified Files
--------------
src/interfaces/libpq/fe-secure-openssl.c | 397 +++++++++++++------------------
src/test/ssl/Makefile | 6 +-
src/test/ssl/README | 4 +
src/test/ssl/ServerSetup.pm | 6 +-
src/test/ssl/ssl/client+client_ca.crt | 25 ++
src/test/ssl/t/001_ssltests.pl | 10 +-
6 files changed, 211 insertions(+), 237 deletions(-)