If you have a problem building on Windows due to a openssl != '' error, make the following edit to <node-gyp path>/gyp/pylib/gyp/input.py:
diff --git a/gyp/pylib/gyp/input.py b/gyp/pylib/gyp/input.py
index 354958b..bb982eb 100644
--- a/gyp/pylib/gyp/input.py
+++ b/gyp/pylib/gyp/input.py
@@ -1190,7 +1190,7 @@ def EvalSingleCondition(cond_expr, true_dict, false_dict, phase, variables, buil
else:
ast_code = compile(cond_expr_expanded, "<string>", "eval")
cached_conditions_asts[cond_expr_expanded] = ast_code
- env = {"__builtins__": {}, "v": StrictVersion}
+ env = {"__builtins__": {"openssl_fips": ""}, "v": StrictVersion}
if eval(ast_code, env, variables):
return true_dict
return false_dict