QVault
QVault is the encrypted key-value store library for Qt/C++.
The library is using OpenSSL for data encryption, specifically:
- PKCS5_PBKDF2_HMAC_SHA1 for key derivation,
- EVP_aes_256_cbc cipher for encryption,
- HMAC w. EVP_sha256 for digest.
The library has been built with Qt5 (OpenSource) and C++11.
Goals
The goal was to make the implementation the most secure, rather than super performant. A typical usage of such a store is to persist user credentials, encryption keys and other sensistive data (of small amount) on the disk that are accessed by "unlocking" the store with a password. When store is locked, no "open text" data remains in memory, including AES encryption keys.
Usage
For the very first time, a user shall create a vault instance protected with a password:
#include <QVault.h>
bool success = QVault::create("~/vault.bin", "mystrongpassword");After the store is created, the user must unlock it to being able set/get values:
QVault vault("~/vault.bin");
bool success = vault.unlock("mystrongpassword");
// set a key-value pair
vault.setValue("btc-wallet-key", btcWalletKey);
// get a value for the key
bool ok;
QString btcWalletKey = vault.getValue("btc-walled-key", &ok).toString();To change the password at any time (the store must be unlocked, of course):
bool success = vault.changePassword("mynewstrongpassword");After you finished accessing the values, just lock() it to ensure no encryption keys or any data left in memory:
vault.lock()Notes
- All methods are synchronous and all write operations will commit all changes to the disk.
- You cannot enumerate keys by design, because getting all keys are insecure operation.
- You will need OpenSSL dev libs to be installed in your environment for this code to be built.
License
GPLv3