Method encrypt_key

libcppcryptfs/config/cryptconfig.cpp:721–852

bool CryptConfig::encrypt_key(const wchar_t* password, const BYTE* masterkey, string& base64encryptedmasterkey, string& scryptSalt, wstring& error_mes)
{
	bool bRet = true;

	shared_ptr<EVP_CIPHER_CTX> context = nullptr;

	unsigned char* encrypted_key = nullptr;

	LockZeroBuffer<unsigned char> pwkey(MASTER_KEY_LEN, false);
	LockZeroBuffer<unsigned char> pwkeyHKDF(MASTER_KEY_LEN, false);

	if (!pwkey.IsLocked() || !pwkeyHKDF.IsLocked()) {
		error_mes = LocUtils::GetStringFromResources(IDS_PWKEY_NOT_LOCKED);
		return false;
	}

	try {

		if (masterkey) {
			if (m_pKeyBuf) {
				error_mes = LocUtils::GetStringFromResources(IDS_MASTER_KEY_ALREADY_SET);
				return false;
			}

			m_pKeyBuf = new LockZeroBuffer<unsigned char>(DEFAULT_KEY_LEN, false);

			if (!m_pKeyBuf->IsLocked()) {
				error_mes = LocUtils::GetStringFromResources(IDS_CANNOT_LOCK_KEY_BUFFER);
				throw(-1);
			}

			m_keybuf_manager.RegisterBuf(m_pKeyBuf);

			memcpy(m_pKeyBuf->m_buf, masterkey, DEFAULT_KEY_LEN);
		}

		m_encrypted_key_salt.resize(SALT_LEN);

		if (!get_sys_random_bytes(&m_encrypted_key_salt[0], SALT_LEN)) {
			error_mes = LocUtils::GetStringFromResources(IDS_FAILED_GET_RANDOM);
			throw(-1);
		}

		LockZeroBuffer<char> utf8pass(256, false);
		if (!utf8pass.IsLocked()) {
			error_mes = LocUtils::GetStringFromResources(IDS_UTF8PASS_NOT_LOCKED);
			return false;
		}

		if (!unicode_to_utf8(password, utf8pass.m_buf, utf8pass.m_len - 1)) {
			error_mes = LocUtils::GetStringFromResources(IDS_CANNOT_CONVERT_PASS_UTF8);
			throw(-1);
		}


		int result = EVP_PBE_scrypt(utf8pass.m_buf, strlen(utf8pass.m_buf), &m_encrypted_key_salt[0],
			m_encrypted_key_salt.size(), m_N, m_R, m_P, scrypt_mem(), pwkey.m_buf,
			GetMasterKeyLength());