95 lines
3.4 KiB
Solidity
95 lines
3.4 KiB
Solidity
pragma solidity =0.5.16;
|
|
|
|
import './interfaces/IUniswapV2ERC20.sol';
|
|
import './libraries/SafeMath.sol';
|
|
|
|
contract UniswapV2ERC20 is IUniswapV2ERC20 {
|
|
using SafeMath for uint;
|
|
|
|
string public constant name = 'Uniswap V2';
|
|
string public constant symbol = 'UNI-V2';
|
|
uint8 public constant decimals = 18;
|
|
uint public totalSupply;
|
|
mapping(address => uint) public balanceOf;
|
|
mapping(address => mapping(address => uint)) public allowance;
|
|
|
|
bytes32 public DOMAIN_SEPARATOR;
|
|
// keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
|
|
bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
|
|
mapping(address => uint) public nonces;
|
|
|
|
event Approval(address indexed owner, address indexed spender, uint value);
|
|
event Transfer(address indexed from, address indexed to, uint value);
|
|
|
|
constructor() public {
|
|
uint chainId;
|
|
assembly {
|
|
chainId := chainid
|
|
}
|
|
DOMAIN_SEPARATOR = keccak256(
|
|
abi.encode(
|
|
keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
|
|
keccak256(bytes(name)),
|
|
keccak256(bytes('1')),
|
|
chainId,
|
|
address(this)
|
|
)
|
|
);
|
|
}
|
|
|
|
function _mint(address to, uint value) internal {
|
|
totalSupply = totalSupply.add(value);
|
|
balanceOf[to] = balanceOf[to].add(value);
|
|
emit Transfer(address(0), to, value);
|
|
}
|
|
|
|
function _burn(address from, uint value) internal {
|
|
balanceOf[from] = balanceOf[from].sub(value);
|
|
totalSupply = totalSupply.sub(value);
|
|
emit Transfer(from, address(0), value);
|
|
}
|
|
|
|
function _approve(address owner, address spender, uint value) private {
|
|
allowance[owner][spender] = value;
|
|
emit Approval(owner, spender, value);
|
|
}
|
|
|
|
function _transfer(address from, address to, uint value) private {
|
|
balanceOf[from] = balanceOf[from].sub(value);
|
|
balanceOf[to] = balanceOf[to].add(value);
|
|
emit Transfer(from, to, value);
|
|
}
|
|
|
|
function approve(address spender, uint value) external returns (bool) {
|
|
_approve(msg.sender, spender, value);
|
|
return true;
|
|
}
|
|
|
|
function transfer(address to, uint value) external returns (bool) {
|
|
_transfer(msg.sender, to, value);
|
|
return true;
|
|
}
|
|
|
|
function transferFrom(address from, address to, uint value) external returns (bool) {
|
|
if (allowance[from][msg.sender] != uint(-1)) {
|
|
allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
|
|
}
|
|
_transfer(from, to, value);
|
|
return true;
|
|
}
|
|
|
|
function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
|
|
require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
|
|
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, 'UniswapV2: INVALID_SIGNATURE');
|
|
_approve(owner, spender, value);
|
|
}
|
|
}
|