Add OpenSSL 3.x ABI cross-compatibility test.

Author: daztucker

.github/run_test.sh

@@ -41,6 +41,17 @@ else
     ${env} make ${TEST_TARGET} SKIP_LTESTS="${SKIP_LTESTS}" LTESTS="${LTESTS}"
 fi
 
+# Replace our self-built with the distro-provided one before running the tests
+# again.
+case "$1" in
+    openssl-3.*)
+	${SUDO} cp /lib/x86_64-linux-gnu/libcrypto.so.3 /opt/openssl/lib64/libcrypto.so.3
+	if [ -z "${TEST_SSH_SSHD_CONFOPTS}" ]; then
+		SSHD_CONFOPTS=AcceptEnv=OpenSSL3_ABI_Test
+	fi
+	;;
+esac
+
 if [ ! -z "${SSHD_CONFOPTS}" ]; then
     echo "rerunning t-exec with TEST_SSH_SSHD_CONFOPTS='${SSHD_CONFOPTS}'"
     if [ -z "${LTESTS}" ]; then