add decryption

src/core.cpp

@@ -1070,6 +1070,8 @@ bool Core::loadConfiguration()
             qWarning() << "Core: tox_load failed with error "<<error;
         }
         else if (error == 1) // Encrypted data save
+        {
+            if (!pwhash)
             {
                 qWarning() << "Core: Can not open encrypted tox save";
                 if (QMessageBox::Ok != QMessageBox::warning(nullptr, tr("Encrypted profile"),
@@ -1081,6 +1083,15 @@ bool Core::loadConfiguration()
                     return false;
                 }
             }
+            else
+            { /*
+                while (error != 0)
+                {
+                    error = tox_encrypted_load(tox, reinterpret_cast<uint8_t *>(data.data()), data.size(), pwhash, TOX_HASH_LENGTH);
+                    // something something QInputDialog new password
+                } */
+            }
+        }
     }
 
     configurationFile.close();
@@ -1467,6 +1478,20 @@ QByteArray Core::encryptData(const QByteArray& data)
     return QByteArray(reinterpret_cast<char*>(encrypted), data.size() + tox_pass_encryption_extra_length());
 }
 
+QByteArray Core::decryptData(const QByteArray& data)
+{
+    if (!pwhash)
+        return QByteArray();
+    int sz = data.size() - tox_pass_encryption_extra_length();
+    uint8_t decrypted[sz];
+    if (tox_pass_decrypt(reinterpret_cast<const uint8_t*>(data.data()), data.size(), pwhash, TOX_HASH_LENGTH, decrypted) != sz)
+    {
+        qWarning() << "Core::decryptData: decryption failed";
+        return QByteArray();
+    }
+    return QByteArray(reinterpret_cast<char*>(decrypted), sz);
+}
+
 bool Core::encryptFile(const QString& path)
 {
     if (!pwhash)
@@ -1495,3 +1520,22 @@ bool Core::encryptFile(const QString& path)
     file.close();
     return true;
 }
+
+QByteArray Core::decryptFile(const QString& path)
+{
+    if (!pwhash)
+        return QByteArray();
+    QFile file(path);
+    if (!file.exists()) {
+        qWarning() << "Core::decryptFile: file" << path << "DNE";
+        return QByteArray();
+    }
+    if (!file.open(QIODevice::ReadOnly)) {
+        qCritical() << "Core::decryptFile:" << path << " cannot be opened";
+        return QByteArray();
+    }
+    QByteArray data = file.readAll();
+    file.close();
+
+    return decryptData(data);
+}

src/core.h

@@ -98,6 +98,8 @@ public slots:
     void clearPassword();
     bool encryptFile(const QString& path);
     QByteArray encryptData(const QByteArray& data);
+    QByteArray decryptData(const QByteArray& data);
+    QByteArray decryptFile(const QString& path);
 
 signals:
     void connected();