Better to notify users about the HD seed rotation and the new
backup requirement before executing the encryption process.
Ensuring they are prepared to update previous backups and
securely safeguard the updated wallet file.
Co-authored-by: jonatack <jon@atack.com>
Since users may have thought the null characters in their
passphrases were actually evaluated prior to this change,
they may be surprised to learn that their passphrases no
longer work. Give them feedback to explain how to remedy
the issue.
`SecureString` is a `std::string` specialization with
a secure allocator. However, it's treated like a C-
string (no explicit length and null-terminated). This
can cause unexpected behavior. For instance, if a user
enters a passphrase with an embedded null character
(which is possible through Qt and the JSON-RPC), it will
ignore any characters after the null, giving the user
a false sense of security.
Instead of assigning `SecureString` via `std::string::c_str()`,
assign it via a `std::string_view` of the original. This
explicitly captures the size and doesn't make any extraneous
copies in memory.
`m_relock_mutex` is introduced so that the passphrase is not
deleted from memory when the timeout provided in
`walletpassphrase` is up, but the wallet is still rescanning.
Wallet passphrases are needed to top up the keypool during a
rescan. The following RPCs need the passphrase when rescanning:
- `importdescriptors`
- `rescanblockchain`
The following RPCs use the information about whether or not the
passphrase is being used to ensure that full rescans are able to
take place:
- `walletlock`
- `encryptwallet`
- `walletpassphrasechange`
This is required for removing the UniValue copy constructor.
-BEGIN VERIFY SCRIPT-
sed -i 's/return NullUniValue/return UniValue::VNULL/g' $(git grep -l NullUniValue ':(exclude)src/univalue')
-END VERIFY SCRIPT-
