pgsql: Don't reflect unescaped cert data to the logs

Don't reflect unescaped cert data to the logs

Commit 3a0e385048 introduced a new path for unauthenticated bytes from
the client certificate to be printed unescaped to the logs. There are a
handful of these already, but it doesn't make sense to keep making the
problem worse. \x-escape any unprintable bytes.

The test case introduces a revoked UTF-8 certificate. This requires the
addition of the `-utf8` flag to `openssl req`. Since the existing
certificates all use an ASCII subset, this won't modify the existing
certificates' subjects if/when they get regenerated; this was verified
experimentally with

$ make sslfiles-clean
$ make sslfiles

Unfortunately the test can't be run in the CI yet due to a test timing
issue; see 55828a6b60.

Author: Jacob Champion <jchampion(at)timescale(dot)com>
Discussion: https://www.postgresql.org/message-id/CAAWbhmgsvHrH9wLU2kYc3pOi1KSenHSLAHBbCVmmddW6-mc_=w@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/257eb57b50f7c65467bfc2f4d579622fa13f3370

Modified Files
--------------
src/backend/libpq/be-secure-openssl.c | 57 ++++++++++++++-----------
src/test/ssl/conf/client-revoked-utf8.config | 13 ++++++
src/test/ssl/ssl/client-crldir/9bb9e3c3.r0 | 19 +++++----
src/test/ssl/ssl/client-revoked-utf8.crt | 18 ++++++++
src/test/ssl/ssl/client-revoked-utf8.key | 27 ++++++++++++
src/test/ssl/ssl/client.crl | 19 +++++----
src/test/ssl/ssl/root+client-crldir/9bb9e3c3.r0 | 19 +++++----
src/test/ssl/ssl/root+client.crl | 19 +++++----
src/test/ssl/sslfiles.mk | 10 +++--
src/test/ssl/t/001_ssltests.pl | 13 ++++++
src/test/ssl/t/SSL/Backend/OpenSSL.pm | 3 +-
11 files changed, 150 insertions(+), 67 deletions(-)