fix: webauthn base64 url encoding

contracts/smart-account/modules/PasskeyRegistryModule.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.8.23;
 
 import {BaseAuthorizationModule} from "./BaseAuthorizationModule.sol";
 import {UserOperation} from "@account-abstraction/contracts/interfaces/UserOperation.sol";
-import {Base64} from "@openzeppelin/contracts/utils/Base64.sol";
+import {Base64} from "solady/utils/Base64.sol";
 import {Secp256r1, PassKeyId} from "./PasskeyValidationModules/Secp256r1.sol";
 import {EIP1271_MAGIC_VALUE} from "contracts/smart-account/interfaces/ISignatureValidator.sol";
 import {IPasskeyRegistryModule} from "../interfaces/modules/IPasskeyRegistryModule.sol";
@@ -163,9 +163,7 @@ contract PasskeyRegistryModule is
                 (bytes32, uint256, uint256, bytes, string, string)
             );
         (keyHash);
-        string memory opHashBase64 = Base64.encode(
-            bytes.concat(userOpDataHash)
-        );
+        string memory opHashBase64 = Base64.encode(abi.encodePacked(userOpDataHash), true, true);
         string memory clientDataJSON = string.concat(
             clientDataJSONPre,
             opHashBase64,

package.json

@@ -89,10 +89,11 @@
     "@ethersproject/constants": "^5.6.1",
     "@types/elliptic": "^6.4.18",
     "axios": "^1.4.0",
-    "ethereumjs-util": "^7.1.0",
-    "hardhat-tracer": "^2.7.0",
     "bn.js": "^5.2.1",
     "dotenv": "^16.0.3",
-    "elliptic": "^6.5.4"
+    "elliptic": "^6.5.4",
+    "ethereumjs-util": "^7.1.0",
+    "hardhat-tracer": "^2.7.0",
+    "solady": "^0.0.248"
   }
 }

test/module/PasskeyFlow.module.specs.ts

@@ -106,10 +106,11 @@ describe("Passkeys Registry Module:", function () {
     const userOpHash = getUserOpHash(userOp, entryPoint.address, chainId);
     const clientDataJSONPre = '{"type":"webauthn.get","challenge":"';
     const clientDataJSONPost =
-      '","origin":"https://webauthn.me","crossOrigin":false}';
+      '","origin":"http://localhost:3000","crossOrigin":false}';
 
     const userOpDataHashBuffer = Buffer.from(ethers.utils.arrayify(userOpHash));
-    const opHashBase64 = userOpDataHashBuffer.toString("base64");
+    let opHashBase64 = userOpDataHashBuffer.toString("base64");
+    opHashBase64 = convertBase64Url(opHashBase64);
 
     const clientDataJSON = `${clientDataJSONPre}${opHashBase64}${clientDataJSONPost}`;
 
@@ -132,6 +133,9 @@ describe("Passkeys Registry Module:", function () {
     const sigHash = ethers.utils.sha256(
       ethers.utils.hexlify(concatenatedBuffer)
     );
+
+    // console.log("sigHash", sigHash);
+
     const bn = new BN(BigNumber.from(sigHash).toString());
     const sign = keyPair.sign(bn);
 
@@ -164,3 +168,7 @@ describe("Passkeys Registry Module:", function () {
     );
   });
 });
+
+const convertBase64Url = (input: string): string => {
+  return input.replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
+};

yarn.lock

@@ -5615,6 +5615,11 @@ slice-ansi@^4.0.0:
     astral-regex "^2.0.0"
     is-fullwidth-code-point "^3.0.0"
 
+solady@^0.0.248:
+  version "0.0.248"
+  resolved "https://registry.yarnpkg.com/solady/-/solady-0.0.248.tgz#19d02509d490a95320e416ec6a2b36d980e57bcf"
+  integrity sha512-GoiB6UuhM4Co56uBwxvzFLyDEwkMrTMkDDCA4Ft53sv1a7PyW0pj69JXqE6iExswV2aJfCF5OFs61gCEGkX3aw==
+
 [email protected]:
   version "0.7.3"
   resolved "https://registry.yarnpkg.com/solc/-/solc-0.7.3.tgz#04646961bd867a744f63d2b4e3c0701ffdc7d78a"