From 5c0658bd568eb98f5c4be7a9ff29ca1545eee50c Mon Sep 17 00:00:00 2001
From: Bashmunta <georgebashmunta@gmail.com>
Date: Mon, 17 Nov 2025 09:20:25 +0200
Subject: [PATCH 1/4] Optimize ERC-1271 path in isValidSignatureNowCalldata to
 avoid extra allocation

---
 .../utils/cryptography/SignatureChecker.sol   | 33 +++++++++++++++++--
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/contracts/utils/cryptography/SignatureChecker.sol b/contracts/utils/cryptography/SignatureChecker.sol
index de619568990..121229fe1ef 100644
--- a/contracts/utils/cryptography/SignatureChecker.sol
+++ b/contracts/utils/cryptography/SignatureChecker.sol
@@ -50,7 +50,7 @@ library SignatureChecker {
             (address recovered, ECDSA.RecoverError err, ) = ECDSA.tryRecoverCalldata(hash, signature);
             return err == ECDSA.RecoverError.NoError && recovered == signer;
         } else {
-            return isValidERC1271SignatureNow(signer, hash, signature);
+            return isValidERC1271SignatureNowCalldata(signer, hash, signature);
         }
     }
 
@@ -73,8 +73,8 @@ library SignatureChecker {
             // Encoded calldata is :
             // [ 0x00 - 0x03 ] <selector>
             // [ 0x04 - 0x23 ] <hash>
-            // [ 0x24 - 0x44 ] <signature offset> (0x40)
-            // [ 0x44 - 0x64 ] <signature length>
+            // [ 0x24 - 0x43 ] <signature offset> (0x40)
+            // [ 0x44 - 0x63 ] <signature length>
             // [ 0x64 - ...  ] <signature data>
             let ptr := mload(0x40)
             mstore(ptr, selector)
@@ -87,6 +87,33 @@ library SignatureChecker {
         }
     }
 
+    function isValidERC1271SignatureNowCalldata(
+        address signer,
+        bytes32 hash,
+        bytes calldata signature
+    ) internal view returns (bool result) {
+        bytes4 selector = IERC1271.isValidSignature.selector;
+
+        assembly ("memory-safe") {
+            // Encoded calldata is :
+            // [ 0x00 - 0x03 ] <selector>
+            // [ 0x04 - 0x23 ] <hash>
+            // [ 0x24 - 0x43 ] <signature offset> (0x40)
+            // [ 0x44 - 0x63 ] <signature length>
+            // [ 0x64 - ...  ] <signature data>
+            let ptr := mload(0x40)
+            mstore(ptr, selector)
+            mstore(add(ptr, 0x04), hash)
+            mstore(add(ptr, 0x24), 0x40)
+            let length := signature.length
+            mstore(add(ptr, 0x44), length)
+            calldatacopy(add(ptr, 0x64), signature.offset, length)
+
+            let success := staticcall(gas(), signer, ptr, add(length, 0x64), 0x00, 0x20)
+            result := and(success, and(gt(returndatasize(), 0x1f), eq(mload(0x00), selector)))
+        }
+    }
+
     /**
      * @dev Verifies a signature for a given ERC-7913 signer and hash.
      *

From 0ad378ed970c16b24e9f419a5921ca2ed8e0332b Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Tue, 25 Nov 2025 17:08:36 +0100
Subject: [PATCH 2/4] Update SignatureChecker.sol

---
 contracts/utils/cryptography/SignatureChecker.sol | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/contracts/utils/cryptography/SignatureChecker.sol b/contracts/utils/cryptography/SignatureChecker.sol
index 121229fe1ef..ab47f96316c 100644
--- a/contracts/utils/cryptography/SignatureChecker.sol
+++ b/contracts/utils/cryptography/SignatureChecker.sol
@@ -93,6 +93,7 @@ library SignatureChecker {
         bytes calldata signature
     ) internal view returns (bool result) {
         bytes4 selector = IERC1271.isValidSignature.selector;
+        uint256 length = signature.length;
 
         assembly ("memory-safe") {
             // Encoded calldata is :
@@ -105,7 +106,6 @@ library SignatureChecker {
             mstore(ptr, selector)
             mstore(add(ptr, 0x04), hash)
             mstore(add(ptr, 0x24), 0x40)
-            let length := signature.length
             mstore(add(ptr, 0x44), length)
             calldatacopy(add(ptr, 0x64), signature.offset, length)
 

From 6e489e70baa00c1a6d8bb07d40baebd9d45e9ca5 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Wed, 26 Nov 2025 16:03:59 +0100
Subject: [PATCH 3/4] testing

---
 test/utils/cryptography/SignatureChecker.test.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/test/utils/cryptography/SignatureChecker.test.js b/test/utils/cryptography/SignatureChecker.test.js
index 82561d53877..99b4f694adc 100644
--- a/test/utils/cryptography/SignatureChecker.test.js
+++ b/test/utils/cryptography/SignatureChecker.test.js
@@ -58,7 +58,12 @@ describe('SignatureChecker (ERC1271)', function () {
   });
 
   describe('ERC1271 wallet', function () {
-    for (const fn of ['isValidERC1271SignatureNow', 'isValidSignatureNow', 'isValidSignatureNowCalldata']) {
+    for (const fn of [
+      'isValidERC1271SignatureNow',
+      'isValidERC1271SignatureNowCalldata',
+      'isValidSignatureNow',
+      'isValidSignatureNowCalldata',
+    ]) {
       describe(fn, function () {
         it('with matching signer and signature', async function () {
           await expect(

From 0f5d11bfcf0ab5013a6a53898152d16f26f31351 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Wed, 26 Nov 2025 16:05:16 +0100
Subject: [PATCH 4/4] Add changeset entry

---
 .changeset/fuzzy-lizards-do.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/fuzzy-lizards-do.md

diff --git a/.changeset/fuzzy-lizards-do.md b/.changeset/fuzzy-lizards-do.md
new file mode 100644
index 00000000000..02545606de7
--- /dev/null
+++ b/.changeset/fuzzy-lizards-do.md
@@ -0,0 +1,5 @@
+---
+'openzeppelin-solidity': minor
+---
+
+`SignatureChecker`: Add `isValidERC1271SignatureNowCalldata`, a variant of `isValidERC1271SignatureNow` that takes the signature from calldata.