refactor endian conversions to own lib

contracts/src/EndianConversions.sol

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+library EndianConversions {
+    function toLittleEndian64(uint64 v) internal pure returns (bytes8) {
+        v = ((v & 0xFF00FF00FF00FF00) >> 8) | ((v & 0x00FF00FF00FF00FF) << 8);
+        v = ((v & 0xFFFF0000FFFF0000) >> 16) | ((v & 0x0000FFFF0000FFFF) << 16);
+        v = ((v & 0xFFFFFFFF00000000) >> 32) | ((v & 0x00000000FFFFFFFF) << 32);
+        return bytes8(v);
+    }
+
+    function toLittleEndian(uint256 v) internal pure returns (bytes32) {
+        v = ((v & 0xFF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00) >> 8)
+            | ((v & 0x00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF) << 8);
+        v = ((v & 0xFFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000) >> 16)
+            | ((v & 0x0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF) << 16);
+        v = ((v & 0xFFFFFFFF00000000FFFFFFFF00000000FFFFFFFF00000000FFFFFFFF00000000) >> 32)
+            | ((v & 0x00000000FFFFFFFF00000000FFFFFFFF00000000FFFFFFFF00000000FFFFFFFF) << 32);
+        v = ((v & 0xFFFFFFFFFFFFFFFF0000000000000000FFFFFFFFFFFFFFFF0000000000000000) >> 64)
+            | ((v & 0x0000000000000000FFFFFFFFFFFFFFFF0000000000000000FFFFFFFFFFFFFFFF) << 64);
+        v = (v >> 128) | (v << 128);
+        return bytes32(v);
+    }
+}

contracts/src/RotateLib.sol

@@ -1,22 +1,10 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
+import { EndianConversions } from "./EndianConversions.sol";
 
 library RotateLib {
 
-    function toLittleEndian(uint256 v) internal pure returns (bytes32) {
-        v = ((v & 0xFF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00) >> 8)
-            | ((v & 0x00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF) << 8);
-        v = ((v & 0xFFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000) >> 16)
-            | ((v & 0x0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF) << 16);
-        v = ((v & 0xFFFFFFFF00000000FFFFFFFF00000000FFFFFFFF00000000FFFFFFFF00000000) >> 32)
-            | ((v & 0x00000000FFFFFFFF00000000FFFFFFFF00000000FFFFFFFF00000000FFFFFFFF) << 32);
-        v = ((v & 0xFFFFFFFFFFFFFFFF0000000000000000FFFFFFFFFFFFFFFF0000000000000000) >> 64)
-            | ((v & 0x0000000000000000FFFFFFFFFFFFFFFF0000000000000000FFFFFFFFFFFFFFFF) << 64);
-        v = (v >> 128) | (v << 128);
-        return bytes32(v);
-    }
-
     struct RotateInput {
         bytes32 syncCommitteeSSZ;
         bytes32 syncCommitteePoseidon;
@@ -31,7 +19,7 @@ library RotateLib {
     function toInputCommitment(RotateInput memory args, bytes32 finalizedHeaderRoot) internal pure returns (uint256[65] memory) {
         uint256[65] memory inputs;
 
-        inputs[0] = uint256(toLittleEndian(uint256(args.syncCommitteePoseidon)));
+        inputs[0] = uint256(EndianConversions.toLittleEndian(uint256(args.syncCommitteePoseidon)));
 
         uint256 syncCommitteeSSZNumeric = uint256(args.syncCommitteeSSZ);
         for (uint256 i = 0; i < 32; i++) {

contracts/src/SyncStepLib.sol

@@ -1,8 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
-import "forge-std/console.sol";
-
+import { EndianConversions } from "./EndianConversions.sol";
 
 library SyncStepLib {
     struct SyncStepInput {
@@ -13,26 +12,6 @@ library SyncStepLib {
         bytes32 executionPayloadRoot;
     }
 
-    function toLittleEndian64(uint64 v) internal pure returns (bytes8) {
-        v = ((v & 0xFF00FF00FF00FF00) >> 8) | ((v & 0x00FF00FF00FF00FF) << 8);
-        v = ((v & 0xFFFF0000FFFF0000) >> 16) | ((v & 0x0000FFFF0000FFFF) << 16);
-        v = ((v & 0xFFFFFFFF00000000) >> 32) | ((v & 0x00000000FFFFFFFF) << 32);
-        return bytes8(v);
-    }
-
-    function toLittleEndian(uint256 v) internal pure returns (bytes32) {
-        v = ((v & 0xFF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00) >> 8)
-            | ((v & 0x00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF00FF) << 8);
-        v = ((v & 0xFFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000) >> 16)
-            | ((v & 0x0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF0000FFFF) << 16);
-        v = ((v & 0xFFFFFFFF00000000FFFFFFFF00000000FFFFFFFF00000000FFFFFFFF00000000) >> 32)
-            | ((v & 0x00000000FFFFFFFF00000000FFFFFFFF00000000FFFFFFFF00000000FFFFFFFF) << 32);
-        v = ((v & 0xFFFFFFFFFFFFFFFF0000000000000000FFFFFFFFFFFFFFFF0000000000000000) >> 64)
-            | ((v & 0x0000000000000000FFFFFFFFFFFFFFFF0000000000000000FFFFFFFFFFFFFFFF) << 64);
-        v = (v >> 128) | (v << 128);
-        return bytes32(v);
-    }
-
     /**
     * @notice Compute the public input commitment for the sync step given this input.
     *         This must always match the prodecure used in lightclient-circuits/src/sync_step_circuit.rs - SyncStepCircuit::instance()
@@ -42,14 +21,14 @@ library SyncStepLib {
      */
     function toInputCommitment(SyncStepInput memory args, bytes32 keysPoseidonCommitment) internal pure returns (uint256) {
         bytes32 h = sha256(abi.encodePacked(
-            toLittleEndian64(args.attestedSlot),
-            toLittleEndian64(args.finalizedSlot),
-            toLittleEndian64(args.participation),
+            EndianConversions.toLittleEndian64(args.attestedSlot),
+            EndianConversions.toLittleEndian64(args.finalizedSlot),
+            EndianConversions.toLittleEndian64(args.participation),
             args.finalizedHeaderRoot,
             args.executionPayloadRoot,
             keysPoseidonCommitment
         ));
-        uint256 commitment = uint256(toLittleEndian(uint256(h)));
+        uint256 commitment = uint256(EndianConversions.toLittleEndian(uint256(h)));
         return commitment & ((uint256(1) << 253) - 1); // truncated to 253 bits
     }
 }