Contract Source Code:
// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity 0.8.11;
// External references
import { ERC20 } from "@rari-capital/solmate/src/tokens/ERC20.sol";
// Internal references
import { Trust } from "@sense-finance/v1-utils/src/Trust.sol";
/// @title Base Token
contract Token is ERC20, Trust {
constructor(
string memory _name,
string memory _symbol,
uint8 _decimals,
address _trusted
) ERC20(_name, _symbol, _decimals) Trust(_trusted) {}
/// @param usr The address to send the minted tokens
/// @param amount The amount to be minted
function mint(address usr, uint256 amount) public requiresTrust {
_mint(usr, amount);
}
/// @param usr The address from where to burn tokens from
/// @param amount The amount to be burned
function burn(address usr, uint256 amount) public requiresTrust {
_burn(usr, amount);
}
}
// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;
/// @notice Modern and gas efficient ERC20 + EIP-2612 implementation.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/tokens/ERC20.sol)
/// @author Modified from Uniswap (https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol)
/// @dev Do not manually set balances without updating totalSupply, as the sum of all user balances must not exceed it.
abstract contract ERC20 {
/*///////////////////////////////////////////////////////////////
EVENTS
//////////////////////////////////////////////////////////////*/
event Transfer(address indexed from, address indexed to, uint256 amount);
event Approval(address indexed owner, address indexed spender, uint256 amount);
/*///////////////////////////////////////////////////////////////
METADATA STORAGE
//////////////////////////////////////////////////////////////*/
string public name;
string public symbol;
uint8 public immutable decimals;
/*///////////////////////////////////////////////////////////////
ERC20 STORAGE
//////////////////////////////////////////////////////////////*/
uint256 public totalSupply;
mapping(address => uint256) public balanceOf;
mapping(address => mapping(address => uint256)) public allowance;
/*///////////////////////////////////////////////////////////////
EIP-2612 STORAGE
//////////////////////////////////////////////////////////////*/
bytes32 public constant PERMIT_TYPEHASH =
keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
uint256 internal immutable INITIAL_CHAIN_ID;
bytes32 internal immutable INITIAL_DOMAIN_SEPARATOR;
mapping(address => uint256) public nonces;
/*///////////////////////////////////////////////////////////////
CONSTRUCTOR
//////////////////////////////////////////////////////////////*/
constructor(
string memory _name,
string memory _symbol,
uint8 _decimals
) {
name = _name;
symbol = _symbol;
decimals = _decimals;
INITIAL_CHAIN_ID = block.chainid;
INITIAL_DOMAIN_SEPARATOR = computeDomainSeparator();
}
/*///////////////////////////////////////////////////////////////
ERC20 LOGIC
//////////////////////////////////////////////////////////////*/
function approve(address spender, uint256 amount) public virtual returns (bool) {
allowance[msg.sender][spender] = amount;
emit Approval(msg.sender, spender, amount);
return true;
}
function transfer(address to, uint256 amount) public virtual returns (bool) {
balanceOf[msg.sender] -= amount;
// Cannot overflow because the sum of all user
// balances can't exceed the max uint256 value.
unchecked {
balanceOf[to] += amount;
}
emit Transfer(msg.sender, to, amount);
return true;
}
function transferFrom(
address from,
address to,
uint256 amount
) public virtual returns (bool) {
uint256 allowed = allowance[from][msg.sender]; // Saves gas for limited approvals.
if (allowed != type(uint256).max) allowance[from][msg.sender] = allowed - amount;
balanceOf[from] -= amount;
// Cannot overflow because the sum of all user
// balances can't exceed the max uint256 value.
unchecked {
balanceOf[to] += amount;
}
emit Transfer(from, to, amount);
return true;
}
/*///////////////////////////////////////////////////////////////
EIP-2612 LOGIC
//////////////////////////////////////////////////////////////*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) public virtual {
require(deadline >= block.timestamp, "PERMIT_DEADLINE_EXPIRED");
// Unchecked because the only math done is incrementing
// the owner's nonce which cannot realistically overflow.
unchecked {
bytes32 digest = keccak256(
abi.encodePacked(
"\x19\x01",
DOMAIN_SEPARATOR(),
keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
)
);
address recoveredAddress = ecrecover(digest, v, r, s);
require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNER");
allowance[recoveredAddress][spender] = value;
}
emit Approval(owner, spender, value);
}
function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
return block.chainid == INITIAL_CHAIN_ID ? INITIAL_DOMAIN_SEPARATOR : computeDomainSeparator();
}
function computeDomainSeparator() internal view virtual returns (bytes32) {
return
keccak256(
abi.encode(
keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
keccak256(bytes(name)),
keccak256("1"),
block.chainid,
address(this)
)
);
}
/*///////////////////////////////////////////////////////////////
INTERNAL MINT/BURN LOGIC
//////////////////////////////////////////////////////////////*/
function _mint(address to, uint256 amount) internal virtual {
totalSupply += amount;
// Cannot overflow because the sum of all user
// balances can't exceed the max uint256 value.
unchecked {
balanceOf[to] += amount;
}
emit Transfer(address(0), to, amount);
}
function _burn(address from, uint256 amount) internal virtual {
balanceOf[from] -= amount;
// Cannot underflow because a user's balance
// will never be larger than the total supply.
unchecked {
totalSupply -= amount;
}
emit Transfer(from, address(0), amount);
}
}
// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.7.0;
/// @notice Ultra minimal authorization logic for smart contracts.
/// @author From https://github.com/Rari-Capital/solmate/blob/fab107565a51674f3a3b5bfdaacc67f6179b1a9b/src/auth/Trust.sol
abstract contract Trust {
event UserTrustUpdated(address indexed user, bool trusted);
mapping(address => bool) public isTrusted;
constructor(address initialUser) {
isTrusted[initialUser] = true;
emit UserTrustUpdated(initialUser, true);
}
function setIsTrusted(address user, bool trusted) public virtual requiresTrust {
isTrusted[user] = trusted;
emit UserTrustUpdated(user, trusted);
}
modifier requiresTrust() {
require(isTrusted[msg.sender], "UNTRUSTED");
_;
}
}