* Create a `LockTime::unlocked` helper constructor
Returns a `LockTime` that is unlocked at the genesis block.
* Return `Option<LockTime>` from `lock_time` method
Prepare to return `None` for when a transaction has its lock time
disabled.
* Return `None` instead of zero `LockTime`
Because a zero lock time means that the transaction was unlocked at the
genesis block, so it was never actually locked.
* Rephrase zero lock time check comment
Clarify that the check is not redundant, and is necessary for the
genesis transaction.
Co-authored-by: teor <teor@riseup.net>
* Add a `transparent::Input::sequence` getter method
Retrieve a transparent input's sequence number.
* Check if lock time is enabled by a sequence number
Validate the consensus rule that the lock time is only enabled if at
least one transparent input has a value different from `u32::MAX` as its
sequence number.
* Add more Zcash specific details to comment
Explain the Zcash specific lock time behaviors.
Co-authored-by: teor <teor@riseup.net>
* Add `time` field to `Request::Block` variant
The block time to use to check if the transaction was unlocked and
allowed to be included in the block.
* Add `Request::block_time` getter
Returns the block time for the block that owns the transaction being
validated or the current time plus a tolerance for mempool transactions.
* Validate transaction lock times
If they are enabled by a transaction's transparent input sequence
numbers, make sure that they are in the past.
* Add comments with consensus rule parts
Make it easier to map what part of the consensus rule each match arm is
responsible for.
Co-authored-by: teor <teor@riseup.net>
* Security: panic if an internally generated time is out of range
If Zebra has a bug where it generates blocks, transactions, or meta
addresses with bad times, panic. This avoids sending bad data onto the
network.
(Previously, Zebra would truncate some of these times, silently
corrupting the underlying data.)
Make it clear that deserialization of these objects is infalliable.