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Prefix private constants with underscore #13

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Apr 4, 2024
Merged

Prefix private constants with underscore #13

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20 changes: 10 additions & 10 deletions src/WebAuthn.sol
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Original file line number Diff line number Diff line change
Expand Up @@ -38,22 +38,22 @@ library WebAuthn {

/// @dev Bit 0 of the authenticator data struct, corresponding to the "User Present" bit.
/// See https://www.w3.org/TR/webauthn-2/#flags.
bytes1 private constant AUTH_DATA_FLAGS_UP = 0x01;
bytes1 private constant _AUTH_DATA_FLAGS_UP = 0x01;

/// @dev Bit 2 of the authenticator data struct, corresponding to the "User Verified" bit.
/// See https://www.w3.org/TR/webauthn-2/#flags.
bytes1 private constant AUTH_DATA_FLAGS_UV = 0x04;
bytes1 private constant _AUTH_DATA_FLAGS_UV = 0x04;

/// @dev Secp256r1 curve order / 2 used as guard to prevent signature malleability issue.
uint256 private constant P256_N_DIV_2 = FCL_Elliptic_ZZ.n / 2;
uint256 private constant _P256_N_DIV_2 = FCL_Elliptic_ZZ.n / 2;

/// @dev The precompiled contract address to use for signature verification in the “secp256r1” elliptic curve.
/// See https://github.com/ethereum/RIPs/blob/master/RIPS/rip-7212.md.
address private constant VERIFIER = address(0x100);
address private constant _VERIFIER = address(0x100);

/// @dev The expected type (hash) in the client data JSON when verifying assertion signatures.
/// See https://www.w3.org/TR/webauthn-2/#dom-collectedclientdata-type
bytes32 private constant EXPECTED_TYPE_HASH = keccak256('"type":"webauthn.get"');
bytes32 private constant _EXPECTED_TYPE_HASH = keccak256('"type":"webauthn.get"');

///
/// @notice Verifies a Webauthn Authentication Assertion as described
Expand Down Expand Up @@ -107,15 +107,15 @@ library WebAuthn {
view
returns (bool)
{
if (webAuthnAuth.s > P256_N_DIV_2) {
if (webAuthnAuth.s > _P256_N_DIV_2) {
// guard against signature malleability
return false;
}

// 11. Verify that the value of C.type is the string webauthn.get.
// bytes("type":"webauthn.get").length = 21
string memory _type = webAuthnAuth.clientDataJSON.slice(webAuthnAuth.typeIndex, webAuthnAuth.typeIndex + 21);
if (keccak256(bytes(_type)) != EXPECTED_TYPE_HASH) {
if (keccak256(bytes(_type)) != _EXPECTED_TYPE_HASH) {
return false;
}

Expand All @@ -131,12 +131,12 @@ library WebAuthn {
// Skip 13., 14., 15.

// 16. Verify that the UP bit of the flags in authData is set.
if (webAuthnAuth.authenticatorData[32] & AUTH_DATA_FLAGS_UP != AUTH_DATA_FLAGS_UP) {
if (webAuthnAuth.authenticatorData[32] & _AUTH_DATA_FLAGS_UP != _AUTH_DATA_FLAGS_UP) {
return false;
}

// 17. If user verification is required for this assertion, verify that the User Verified bit of the flags in authData is set.
if (requireUV && (webAuthnAuth.authenticatorData[32] & AUTH_DATA_FLAGS_UV) != AUTH_DATA_FLAGS_UV) {
if (requireUV && (webAuthnAuth.authenticatorData[32] & _AUTH_DATA_FLAGS_UV) != _AUTH_DATA_FLAGS_UV) {
return false;
}

Expand All @@ -149,7 +149,7 @@ library WebAuthn {
bytes32 messageHash = sha256(abi.encodePacked(webAuthnAuth.authenticatorData, clientDataJSONHash));
bytes memory args = abi.encode(messageHash, webAuthnAuth.r, webAuthnAuth.s, x, y);
// try the RIP-7212 precompile address
(bool success, bytes memory ret) = VERIFIER.staticcall(args);
(bool success, bytes memory ret) = _VERIFIER.staticcall(args);
// staticcall will not revert if address has no code
// check return length
// note that even if precompile exists, ret.length is 0 when verification returns false
Expand Down