fix(memory): set secure flag properly

Signed-off-by: Tony Gorez <[email protected]>

Author: tony-go

index.js

@@ -41,6 +41,7 @@ exports.sodium_malloc = function (size) {
 exports.sodium_free = function (buf) {
   if (!buf || !buf.secure) return
 
+  buf.secure = false
   binding.sodium_free(buf.buffer)
 }
 

test/memory.js

@@ -128,6 +128,20 @@ test('sodium_free, double free', function (t) {
   t.ok(buf.byteLength === 0)
 })
 
+test('sodium_free should clear secure flag', function (t) {
+  const buf = sodium.sodium_malloc(32)
+
+  t.ok(buf.secure === true, 'buf.secure is true before free')
+
+  sodium.sodium_free(buf)
+
+  t.ok(buf.byteLength === 0, 'buffer is detached after free')
+  t.ok(buf.secure === false, 'buf.secure is false after free')
+
+  sodium.sodium_free(buf)
+  t.ok(buf.secure === false, 'second free is a no-op, secure stays false')
+})
+
 test.skip('sodium_malloc bounds', function (t) {
   t.throws(function () {
     sodium.sodium_malloc(-1)