fTokenEIP2612Withdrawals

Git Source

Inherits:fTokenActions

fTokens support EIP-2612 permit approvals via signature so this contract implements withdrawals (withdraw / redeem) with signature used for approval of the fToken shares.

Functions

_allowViaPermitEIP2612

creates sharesToPermit_ allowance for owner_ via EIP2612 deadline_ and signature_

function _allowViaPermitEIP2612(address owner_, uint256 sharesToPermit_, uint256 deadline_, bytes calldata signature_)
    internal;

withdrawWithSignature

withdraw amount of assets_ with ERC-2612 permit signature for fToken approval. owner_ signs ERC-2612 permit signature_ to give allowance of fTokens to msg.sender. Note there might be tiny inaccuracies between requested assets_ and actually received assets amount. allowance via signature (sharesToPermit_) should cover previewWithdraw(assets_) plus a little buffer to avoid revert. Inherent trust assumption that msg.sender will set receiver_ and maxSharesBurn_ as owner_ intends (which is always the case when giving allowance to some spender).

function withdrawWithSignature(
    uint256 sharesToPermit_,
    uint256 assets_,
    address receiver_,
    address owner_,
    uint256 maxSharesBurn_,
    uint256 deadline_,
    bytes calldata signature_
) external virtual nonReentrant returns (uint256 shares_);

Parameters

Name	Type	Description
sharesToPermit_	uint256	shares amount to use for EIP2612 permit(). Should cover previewWithdraw(assets_) + small buffer.
assets_	uint256	amount of assets to withdraw
receiver_	address	receiver of withdrawn assets
owner_	address	owner to withdraw from (must be signature signer)
maxSharesBurn_	uint256	maximum accepted amount of shares burned
deadline_	uint256	deadline for signature validity
signature_	bytes	packed signature of signing the EIP712 hash for ERC-2612 permit

Returns

Name	Type	Description
shares_	uint256	burned shares amount

redeemWithSignature

redeem amount of shares_ with ERC-2612 permit signature for fToken approval. owner_ signs ERC-2612 permit signature_ to give allowance of fTokens to msg.sender. Note there might be tiny inaccuracies between requested shares_ to redeem and actually burned shares. allowance via signature must cover shares_ plus a tiny buffer. Inherent trust assumption that msg.sender will set receiver_ and minAmountOut_ as owner_ intends (which is always the case when giving allowance to some spender). Recommended to use withdraw() over redeem because it is more gas efficient and can set specific amount.

function redeemWithSignature(
    uint256 shares_,
    address receiver_,
    address owner_,
    uint256 minAmountOut_,
    uint256 deadline_,
    bytes calldata signature_
) external virtual nonReentrant returns (uint256 assets_);

Parameters

Name	Type	Description
shares_	uint256	amount of shares to redeem
receiver_	address	receiver of withdrawn assets
owner_	address	owner to withdraw from (must be signature signer)
minAmountOut_	uint256	minimum accepted amount of assets withdrawn
deadline_	uint256	deadline for signature validity
signature_	bytes	packed signature of signing the EIP712 hash for ERC-2612 permit

Returns

Name	Type	Description
assets_	uint256	withdrawn assets amount