Staked Token (Aave Safety Module) v1.5

Repository contains a new revision of StakedTokenV3 and StakedAaveV3, equivalent to what is know high-level as Safety Module v1.5.

It is important to highlight that stkAAVE and stkABPT are slightly different, that's the reason why the code intended to use for each one is:

• For stkAAVE: StakedAaveV3
• For stkABPT: StakedTokenV3

Due to complex inheritance chains, a aggregated interface for each Contract is provided as:

• AggregatedStakedAaveV3
• AggregatedStakedTokenV3

Slashing

Thew new StakedTokenV3 includes en enhanced mechanism to facilitate slashing of the underlying by tracking the exchangeRate between $stkToken \leftrightarrow Token$.

The slashing itself must be performed by a slashingAdmin which initially will be the governance short executor. The slashing will result in transferring part of the underlying to a specified address and starting the slashing process by setting a inPostSlashingPeriod flag.

While being in post slashing period, no other slashing can be performed. While accounts can exit the pool no-one can enter the pool in that period.

The community can then use (parts of) the funds for recovery. Once the recovery is finished potentially remaining funds should be returned to the pool and mutualized by the remaining stakers.

Once the slashing is officially settled, accounts can reenter the pool and a new slashing can occur.

Cooldown & Redeeming

The new StakedTokenV3 adjusts the cooldown to no longer cooldown for an arbitrary balance, but instead to cooldown for the minimum balanceOf(account) between cooldown start t0 and withdrawal window end t1.

In practice this means, the cooldown will write the redeem budget to storage once cooldown is triggered and discount from it when there is a redeem action, or a transfer out performed.

While in the current system one can trigger a cooldown for e.g. 100 -> receive 100 and then redeem(200)(after a prolonged cooldown), with the newly introduced mechanic you will only ever be able to redeem(100). If at any point during the cooldown period the balanceOf(account) decreases below the redeem budget registered on cooldown the budget will be decreased to the new balanceOf(account).

GHO

The StakedAaveV3 extends on top of StakedTokenV3 , by adding hooks for managing the GHO discounts via a "transfer hook".

An export of storage layout changes can be found here

Security

External

• SigmaPrime report
• Certora report
• Certora properties

Procedures followed

• A more formal list of properties of the system can be found HERE
• An export of storage layout changes and code diff from the previous implementation can be found HERE
• The test suite of the implementation can be found HERE

Development

Install

cp .env.example .env
forge install

Test

forge test

Diff

Generate a code & storage layout diff.

make diff-all