Function: permit(address owner, address spender, uint256 amount, uint256 deadline, uint8 v, byte[32] r, byte[32] s)

Implementation of the ERC-20 permit allowing approvals to be made via signatures, as defined in EIP-2612.

Inputs

• owner

  • Control: Fully controlled.

  • Constraints: No constraints.

  • Impact: The address of the token owner who signed the message.

• spender

  • Control: Fully controlled.

  • Constraints: No constraints.

  • Impact: The address of the spender contract who can transfer tokens on behalf of the owner.

• amount

  • Control: Fully controlled.

  • Constraints: No constraints.

  • Impact: The maximum amount of tokens that can be transferred by the spender.

• deadline

  • Control: Fully controlled.

  • Constraints: Should be greater than the current timestamp.

  • Impact: A timestamp after which the signature is invalid.

• v

  • Control: Fully controlled.

  • Constraints: No constraints.

  • Impact: The component of the EIP-712 signature that proves the owner’s consent.

• r

  • Control: Fully controlled.

  • Constraints: No constraints.

  • Impact: The component of the EIP-712 signature that proves the owner’s consent.

• s

  • Control: Fully controlled.

  • Constraints: No constraints.

  • Impact: The component of the EIP-712 signature that proves the owner’s consent.

Branches and code coverage (including function calls)

Intended branches

• _approve is called with the expected recovered address.

  Test coverage

Negative behavior

• Revert if signature is invalid and the recovered address does not match the expected owner address.

  Test coverage