test-tool: add iSCSICHAP.Base64 test

Some targets such as LIO support base64 encoded CHAP_R values. Test this
by intercepting hex-encoded CHAP_R responses and converting the value to
base64.
This will fail on targets which don't support base64; we should probably
skip the test instead.
base64 encoding is performed using the gnutls_base64_encode2() function,
so the test is only present for gnutls-enabled builds.

Signed-off-by: David Disseldorp <ddiss@suse.de>

test-tool/iscsi-test-cu.c

@@ -587,6 +587,9 @@ static CU_TestInfo tests_iscsi_nop[] = {
 static CU_TestInfo tests_iscsi_chap[] = {
         { "Simple", test_iscsi_chap_simple },
         { "Invalid", test_iscsi_chap_invalid },
+#ifdef HAVE_LIBGNUTLS
+        { "Base64", test_iscsi_chap_base64 },
+#endif
         CU_TEST_INFO_NULL
 };