Centralize ssl tests' check for whether we're using LibreSSL.

Right now there's only one caller, so that this is merely
an exercise in shoving code from one module to another,
but there will shortly be another one.  It seems better to
avoid having two copies of this highly-subject-to-change test.

Back-patch to v15, where we first introduced some tests that
don't work with LibreSSL.

Reported-by: Thomas Munro <thomas.munro@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/CA+hUKG+fLqyweHqFSBcErueUVT0vDuSNWui-ySz3+d_APmq7dw@mail.gmail.com
Backpatch-through: 15

1 files changed, 17 insertions, 0 deletions

diff --git a/src/test/ssl/t/SSL/Server.pm b/src/test/ssl/t/SSL/Server.pm
index 14277418419..33975b28e8c 100644
--- a/src/test/ssl/t/SSL/Server.pm
+++ b/src/test/ssl/t/SSL/Server.pm
@@ -244,6 +244,23 @@ sub ssl_library
 
 =pod
 
+=item $server->is_libressl()
+
+Detect whether the currently used SSL backend is LibreSSL.
+(Ideally we'd not need this hack, but presently we do.)
+
+=cut
+
+sub is_libressl
+{
+	my $self = shift;
+	my $backend = $self->{backend};
+
+	return $backend->library_is_libressl();
+}
+
+=pod
+
 =item switch_server_cert(params)
 
 Change the configuration to use the given set of certificate, key, ca and