build: Require OpenSSL

refs: #2375

Change-Id: I0fe7c44b9e025bbe9a2e58cf0cab95069e668945
diff --git a/wscript b/wscript
index aa6c002..7364b07 100644
--- a/wscript
+++ b/wscript
@@ -48,11 +48,13 @@
                'doxygen', 'sphinx_build'])
 
     conf.check_cfg(package='libndn-cxx', args=['--cflags', '--libs'],
-                   uselib_store='NDN_CPP', mandatory=True)
+                   uselib_store='NDN_CXX', mandatory=True)
 
     conf.check_cfg(package='liblog4cxx', args=['--cflags', '--libs'],
                    uselib_store='LOG4CXX', mandatory=True)
 
+    conf.check_openssl(mandatory=True)
+
     boost_libs = 'system chrono program_options iostreams thread regex filesystem'
     if conf.options.with_tests:
         conf.env['WITH_TESTS'] = 1
@@ -98,7 +100,7 @@
         name='nsync-objects',
         features='cxx',
         source=bld.path.ant_glob(['nsync/**/*.cc', 'nsync/**/*.proto']),
-        use='BOOST NDN_CPP OPENSSL',
+        use='BOOST NDN_CXX OPENSSL',
         includes='nsync',
         export_includes='nsync',
         )
@@ -109,7 +111,7 @@
         features='cxx',
         source=bld.path.ant_glob(['src/**/*.cpp'],
                                  excl=['src/main.cpp']),
-        use='nsync-objects NDN_CPP BOOST LOG4CXX',
+        use='nsync-objects NDN_CXX BOOST LOG4CXX',
         includes='. src',
         export_includes='. src',
         )