tests/softhsm: Search library near softhsm2-util

On macOS, libsofthsm2.so might be installed in
/usr/local/lib/libsofthsm2.so, /opt/local/lib/libsofthsm2.so, somewhere
in /usr/local/Cellar/softhsm, or on Apple Silicon in
/opt/homebrew/lib/libsofths2.so.

Simplify searching for it by using $PATH, which we know must already
contain softhsm2-util, and then attempt to identify the library relative
to that.

Signed-off-by: Clemens Lang <cllang@redhat.com>

tests/setup-softhsm.sh

@@ -28,7 +28,21 @@ find_softhsm() {
 }
 
 title SECTION "Searching for SoftHSM PKCS#11 library"
+# Attempt to guess the path to libsofthsm2.so relative to that. This fixes
+# auto-detection on platforms such as macOS with MacPorts (and potentially
+# Homebrew).
+#
+# This should never be empty, since we checked for the presence of
+# softhsm2-util above and use it below.
+
+# Strip bin/softhsm2-util
+softhsm_prefix=$(dirname "$(dirname "$(type -p softhsm2-util)")")
+
 find_softhsm \
+    "$softhsm_prefix/lib64/softhsm/libsofthsm2.so" \
+    "$softhsm_prefix/lib/softhsm/libsofthsm2.so" \
+    "$softhsm_prefix/lib64/pkcs11/libsofthsm2.so" \
+    "$softhsm_prefix/lib/pkcs11/libsofthsm2.so" \
     /usr/local/lib/softhsm/libsofthsm2.so \
     /usr/lib64/pkcs11/libsofthsm2.so \
     /usr/lib/pkcs11/libsofthsm2.so \