-
Notifications
You must be signed in to change notification settings - Fork 328
/
EIP712.sol
208 lines (190 loc) · 9.08 KB
/
EIP712.sol
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
/// @notice Contract for EIP-712 typed structured data hashing and signing.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/EIP712.sol)
/// @author Modified from Solbase (https://github.com/Sol-DAO/solbase/blob/main/src/utils/EIP712.sol)
/// @author Modified from OpenZeppelin (https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/cryptography/EIP712.sol)
///
/// @dev Note, this implementation:
/// - Uses `address(this)` for the `verifyingContract` field.
/// - Does NOT use the optional EIP-712 salt.
/// - Does NOT use any EIP-712 extensions.
/// This is for simplicity and to save gas.
/// If you need to customize, please fork / modify accordingly.
abstract contract EIP712 {
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* CONSTANTS AND IMMUTABLES */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev `keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")`.
bytes32 internal constant _DOMAIN_TYPEHASH =
0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f;
uint256 private immutable _cachedThis;
uint256 private immutable _cachedChainId;
bytes32 private immutable _cachedNameHash;
bytes32 private immutable _cachedVersionHash;
bytes32 private immutable _cachedDomainSeparator;
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* CONSTRUCTOR */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev Cache the hashes for cheaper runtime gas costs.
/// In the case of upgradeable contracts (i.e. proxies),
/// or if the chain id changes due to a hard fork,
/// the domain separator will be seamlessly calculated on-the-fly.
constructor() {
_cachedThis = uint256(uint160(address(this)));
_cachedChainId = block.chainid;
string memory name;
string memory version;
if (!_domainNameAndVersionMayChange()) (name, version) = _domainNameAndVersion();
bytes32 nameHash = _domainNameAndVersionMayChange() ? bytes32(0) : keccak256(bytes(name));
bytes32 versionHash =
_domainNameAndVersionMayChange() ? bytes32(0) : keccak256(bytes(version));
_cachedNameHash = nameHash;
_cachedVersionHash = versionHash;
bytes32 separator;
if (!_domainNameAndVersionMayChange()) {
/// @solidity memory-safe-assembly
assembly {
let m := mload(0x40) // Load the free memory pointer.
mstore(m, _DOMAIN_TYPEHASH)
mstore(add(m, 0x20), nameHash)
mstore(add(m, 0x40), versionHash)
mstore(add(m, 0x60), chainid())
mstore(add(m, 0x80), address())
separator := keccak256(m, 0xa0)
}
}
_cachedDomainSeparator = separator;
}
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* FUNCTIONS TO OVERRIDE */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev Please override this function to return the domain name and version.
/// ```
/// function _domainNameAndVersion()
/// internal
/// pure
/// virtual
/// returns (string memory name, string memory version)
/// {
/// name = "Solady";
/// version = "1";
/// }
/// ```
///
/// Note: If the returned result may change after the contract has been deployed,
/// you must override `_domainNameAndVersionMayChange()` to return true.
function _domainNameAndVersion()
internal
view
virtual
returns (string memory name, string memory version);
/// @dev Returns if `_domainNameAndVersion()` may change
/// after the contract has been deployed (i.e. after the constructor).
/// Default: false.
function _domainNameAndVersionMayChange() internal pure virtual returns (bool result) {}
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* HASHING OPERATIONS */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev Returns the EIP-712 domain separator.
function _domainSeparator() internal view virtual returns (bytes32 separator) {
if (_domainNameAndVersionMayChange()) {
separator = _buildDomainSeparator();
} else {
separator = _cachedDomainSeparator;
if (_cachedDomainSeparatorInvalidated()) separator = _buildDomainSeparator();
}
}
/// @dev Returns the hash of the fully encoded EIP-712 message for this domain,
/// given `structHash`, as defined in
/// https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct.
///
/// The hash can be used together with {ECDSA-recover} to obtain the signer of a message:
/// ```
/// bytes32 digest = _hashTypedData(keccak256(abi.encode(
/// keccak256("Mail(address to,string contents)"),
/// mailTo,
/// keccak256(bytes(mailContents))
/// )));
/// address signer = ECDSA.recover(digest, signature);
/// ```
function _hashTypedData(bytes32 structHash) internal view virtual returns (bytes32 digest) {
// We will use `digest` to store the domain separator to save a bit of gas.
if (_domainNameAndVersionMayChange()) {
digest = _buildDomainSeparator();
} else {
digest = _cachedDomainSeparator;
if (_cachedDomainSeparatorInvalidated()) digest = _buildDomainSeparator();
}
/// @solidity memory-safe-assembly
assembly {
// Compute the digest.
mstore(0x00, 0x1901000000000000) // Store "\x19\x01".
mstore(0x1a, digest) // Store the domain separator.
mstore(0x3a, structHash) // Store the struct hash.
digest := keccak256(0x18, 0x42)
// Restore the part of the free memory slot that was overwritten.
mstore(0x3a, 0)
}
}
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* EIP-5267 OPERATIONS */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev See: https://eips.ethereum.org/EIPS/eip-5267
function eip712Domain()
public
view
virtual
returns (
bytes1 fields,
string memory name,
string memory version,
uint256 chainId,
address verifyingContract,
bytes32 salt,
uint256[] memory extensions
)
{
fields = hex"0f"; // `0b01111`.
(name, version) = _domainNameAndVersion();
chainId = block.chainid;
verifyingContract = address(this);
salt = salt; // `bytes32(0)`.
extensions = extensions; // `new uint256[](0)`.
}
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* PRIVATE HELPERS */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev Returns the EIP-712 domain separator.
function _buildDomainSeparator() private view returns (bytes32 separator) {
// We will use `separator` to store the name hash to save a bit of gas.
bytes32 versionHash;
if (_domainNameAndVersionMayChange()) {
(string memory name, string memory version) = _domainNameAndVersion();
separator = keccak256(bytes(name));
versionHash = keccak256(bytes(version));
} else {
separator = _cachedNameHash;
versionHash = _cachedVersionHash;
}
/// @solidity memory-safe-assembly
assembly {
let m := mload(0x40) // Load the free memory pointer.
mstore(m, _DOMAIN_TYPEHASH)
mstore(add(m, 0x20), separator) // Name hash.
mstore(add(m, 0x40), versionHash)
mstore(add(m, 0x60), chainid())
mstore(add(m, 0x80), address())
separator := keccak256(m, 0xa0)
}
}
/// @dev Returns if the cached domain separator has been invalidated.
function _cachedDomainSeparatorInvalidated() private view returns (bool result) {
uint256 cachedChainId = _cachedChainId;
uint256 cachedThis = _cachedThis;
/// @solidity memory-safe-assembly
assembly {
result := iszero(and(eq(chainid(), cachedChainId), eq(address(), cachedThis)))
}
}
}