fix/Crypto: KeyBytes were not being copied after returned by safe_cor…

…e causing a segv as memory was reused by the lib (#96)

src/native/_crypto.js

@@ -20,16 +20,25 @@ function strToBuffer(str) {
 }
 
 function toBuffer(app, key) {
-  let keyArr = key.buffer || key;
-  if (keyArr.length != 32) throw Error("Sign/Enc Keys _must be_ 32 bytes long.")
-  keyArr = t.KEYBYTES(keyArr);
-  return [app, keyArr]
+  let keyArr = key;
+  if (!Buffer.isBuffer(key)) {
+    const b = new Buffer(key);
+    if (b.length != 32) throw Error("Sign/Enc Keys _must be_ 32 bytes long.")
+    keyArr = t.KEYBYTES(b).ref().readPointer(0);
+  }
+  return [app, keyArr];
 }
 
 function appStrToBuffer(appPtr, str) {
   return [appPtr].concat(strToBuffer(str)).concat(Array.prototype.slice.call(arguments, 2))
 }
 
+// Helper to create a copy of the received KEYBYTES array as it might
+// be overwritten after the callback finishes.
+function copyKeyBytesArray(res) {
+  return t.KEYBYTES(ref.reinterpret(res[0], 32));
+}
+
 module.exports = {
   types: {
     SignKeyHandle,
@@ -39,18 +48,18 @@ module.exports = {
   },
   functions: {
     app_pub_sign_key: [t.Void, [t.AppPtr, 'pointer', 'pointer']],
-    sign_key_new: [t.Void, [t.AppPtr, t.KEYBYTES, 'pointer', 'pointer']],
+    sign_key_new: [t.Void, [t.AppPtr, ref.refType(t.KEYBYTES), 'pointer', 'pointer']],
     sign_key_get: [t.Void, [t.AppPtr, SignKeyHandle, 'pointer', 'pointer']],
     sign_key_free: [t.Void, [t.AppPtr, SignKeyHandle, 'pointer', 'pointer']],
 
     app_pub_enc_key: [t.Void, [t.AppPtr, 'pointer', 'pointer']],
     enc_generate_key_pair: [t.Void, [t.AppPtr, 'pointer', 'pointer']],
 
-    enc_pub_key_new: [t.Void, [t.AppPtr, t.KEYBYTES, 'pointer', 'pointer']],
+    enc_pub_key_new: [t.Void, [t.AppPtr, ref.refType(t.KEYBYTES), 'pointer', 'pointer']],
     enc_pub_key_get: [t.Void, [t.AppPtr, EncryptPubKeyHandle, 'pointer', 'pointer']],
     enc_secret_key_free: [t.Void, [t.AppPtr, EncryptPubKeyHandle, 'pointer', 'pointer']],
 
-    enc_secret_key_new: [t.Void, [t.AppPtr, t.KEYBYTES, 'pointer', 'pointer']],
+    enc_secret_key_new: [t.Void, [t.AppPtr, ref.refType(t.KEYBYTES), 'pointer', 'pointer']],
     enc_secret_key_get: [t.Void, [t.AppPtr, EncryptSecKeyHandle, 'pointer', 'pointer']],
     enc_secret_key_free: [t.Void, [t.AppPtr, EncryptSecKeyHandle, 'pointer', 'pointer']],
 
@@ -66,17 +75,17 @@ module.exports = {
   api: {
     app_pub_sign_key: h.Promisified(null, SignKeyHandle),
     sign_key_new: h.Promisified(toBuffer, SignKeyHandle),
-    sign_key_get: h.Promisified(null, t.KEYBYTES),
+    sign_key_get: h.Promisified(null, ['pointer'], copyKeyBytesArray),
     sign_key_free: h.Promisified(null, []),
 
     app_pub_enc_key: h.Promisified(null, EncryptKeyHandle),
     enc_generate_key_pair: h.Promisified(null, [EncryptPubKeyHandle, EncryptSecKeyHandle]),
 
     enc_pub_key_new: h.Promisified(toBuffer, EncryptPubKeyHandle),
-    enc_pub_key_get: h.Promisified(null, t.KEYBYTES),
+    enc_pub_key_get: h.Promisified(null, ['pointer'], copyKeyBytesArray),
 
     enc_secret_key_new: h.Promisified(toBuffer, EncryptPubKeyHandle),
-    enc_secret_key_get: h.Promisified(null, t.KEYBYTES),
+    enc_secret_key_get: h.Promisified(null, ['pointer'], copyKeyBytesArray),
 
     encrypt: h.Promisified(appStrToBuffer, [t.u8Pointer, t.usize], h.asBuffer),
     decrypt: h.Promisified(appStrToBuffer, [t.u8Pointer, t.usize], h.asBuffer),

test/crypto.js

@@ -82,7 +82,7 @@ describe('App Crypto Tests', () => {
         })
     ]).then((r) => should(r[0]).not.equal(r[1])));
 
-    it.skip('generate key pair from raw keys', () => {
+    it('generate key pair from raw keys', () => {
       let rawPubKey;
       let rawPubKeyFromRaw;
       let rawSecKey;