Needed to support automatic migration of old Keysmith storage format.
This is unfortunate, but we have users and we cannot simply break
backwards compatibility with the old storage format (yet).
Previously entering an incorrect password would appear to successfully "unlock" accounts, contrary to expectations.
By introducing a challenge object as part of the master key parameters, an incorrect password can now be detected and signalled accordingly.
This fix introduces a backwards incompatible change to the accounts data as stored on disk, meaning old Keysmith accounts configuration will no longer load and must be recreated from scratch.
One downside of offloading the token computation to a worker thread and having to do token decryption is an increase in latency.
For the case with a few accounts this latency does not matter, but in case of many accounts it can induce a significant delay when refreshing tokens in the UI.
To hide this latency, when computing an OTP token for the current state of the account the logical 'next' token is also computed as well and cached in the Account object.
When the next (re)computation of the OTP token is requested, the cached 'next' value is reused if still valid before the next pair of tokens is being computed.
This way the apparent latency of a token update is reduced to an near immediate property update in the UI, hiding the actual latency of the computation itself.
This 'optimisation' is implemented in the dumbest possible fashion that can still work.
This means that the code complexity of the change is quite limited, at the cost of rougly doubling the actual work being performed in the worker thread.
With this the AccountStorage module now fully supports some HOTP/TOTP parameters which are uncommon (but still part of HOTP/TOTP specifications).
- Better types for offset, tokenLength. Make this consistent throughout
- Finish support for offset, checksum parameters for HOTP tokens in AccountStorage
- Finish support for hashing algorithm, epoch parameters for TOTP tokens in AccountStorage
- Better API for creating oath::Algorithm instances
- Code formatting (break up long lines)
Issues: #7
With this change account storage and model work with accounts for which an issuer is recorded.
This is a prerequisite for fully supporting otpauth:// URIs (necessary for QR code support) in Keysmith.
Issues: #7, #13
See-Also: https://github.com/google/google-authenticator/wiki/Key-Uri-Format
Two bits of boolean state are introduces to track whether or not:
- an error has occurred
- accounts have been loaded from storage yet
This change paves the way for having error handling UX.
With this change token secrets are encrypted prior to writing them to
storage, and decrypted as and when needed to generate tokens. Additional
validation is performed to verify that token secrets can be decrypted
successfully when loading accounts from storage.
With this change issue #6 should finally be resolved.
With this change an unlock stage is introduced to loading account storage.
Key derivation parameters for a master key are recorded, and the master
password may be supplied to "unlock" the account secret(s) in storage.
This change paves the way for actually decrypting encrypted account
secrets later, and finally solving issue #6.
Johan Ouwerkerk
Bhushan Shah
Yuri Chornoivan