evm: Echidna stateful fuzzing for NttManager (#393)

* Initial fuzzing harness

* forge install: solidity-bytes-utils

v0.8.2

* More fuzz test coverage

* More fuzz tests

* Fix ordering of checks

* Fuzz transfer qol entrypoint

* Refactor transfer fuzzing with fewer assumptions

* More fuzzing progress for arbitrary instructions

* More fuzzing

* Fuzz cancelling

* Get fuzz suite working again

* Fix recent changes and add to CI

* Fix action

.github/workflows/evm.yml

@@ -41,3 +41,32 @@ jobs:
         run: |
           make check-format
         id: check
+
+  echidna:
+    name: echidna
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Install Foundry
+        uses: foundry-rs/foundry-toolchain@v1
+        with:
+          version: nightly
+
+      - name: Run Forge build
+        run: |
+          make test-push0
+        id: build
+
+      - name: Install Echidna
+        run: |
+          curl -LO https://github.com/crytic/echidna/releases/download/v2.2.3/echidna-2.2.3-x86_64-linux.tar.gz
+          tar -xzf echidna-2.2.3-x86_64-linux.tar.gz
+          pip install crytic-compile
+      
+      - name: Run Echidna
+        run: |
+          cd evm
+          ../echidna ./echidna --config echidna.yaml

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "lib/wormhole-solidity-sdk"]
 	path = evm/lib/wormhole-solidity-sdk
 	url = https://github.com/wormhole-foundation/wormhole-solidity-sdk
+[submodule "evm/lib/solidity-bytes-utils"]
+	path = evm/lib/solidity-bytes-utils
+	url = https://github.com/GNSPS/solidity-bytes-utils

Makefile

@@ -36,5 +36,5 @@ test-evm:
 
 # Verify that the contracts do not include PUSH0 opcodes
 test-push0:
-	forge build --extra-output evm.bytecode.opcodes
-	@if grep -qr --include \*.json PUSH0 ./out; then echo "Contract uses PUSH0 instruction" 1>&2; exit 1; else echo "PUSH0 Verification Succeeded"; fi
+	cd evm && forge build --extra-output evm.bytecode.opcodes
+	@if grep -qr --include \*.json PUSH0 ./evm/out; then echo "Contract uses PUSH0 instruction" 1>&2; exit 1; else echo "PUSH0 Verification Succeeded"; fi

evm/echidna.yaml

@@ -0,0 +1,14 @@
+testMode: "assertion"
+
+deployContracts: [
+  ["0x1f1", "TransceiverStructs"],
+]
+
+cryticArgs: ["--compile-libraries=(TransceiverStructs,0x1f1)"]
+
+# Default is 0x6000, but we need to increase this as not compiled via ir
+codeSize: 0x8000
+
+stopOnFail: false
+
+testLimit: 100000

evm/echidna/helpers/FuzzingHelpers.sol

@@ -0,0 +1,70 @@
+pragma solidity >=0.8.8 <0.9.0;
+
+import "./IHevm.sol";
+
+abstract contract FuzzingHelpers {
+    address constant HEVM_ADDRESS = 0x7109709ECfa91a80626fF3989D68f67F5b1DD12D;
+    IHevm hevm = IHevm(HEVM_ADDRESS);
+
+
+    event LogAddress(address);
+    event LogUint256(uint256);
+    event LogString(string);
+    event AssertFail(string);
+
+    // We need this to receive refunds for quotes
+    receive() external payable {}
+
+    function clampBetween(uint256 value, uint256 low, uint256 high) internal returns (uint256){
+        if (value < low || value > high) {
+            uint ans = low + (value % (high - low + 1));
+            return ans;
+        }
+        return value;
+    }
+
+    function extractErrorSelector(
+        bytes memory revertData
+    ) internal returns (uint256) {
+        if (revertData.length < 4) {
+            emit LogString("Return data too short.");
+            return 0;
+        }
+
+        uint256 errorSelector = uint256(
+            (uint256(uint8(revertData[0])) << 24) |
+                (uint256(uint8(revertData[1])) << 16) |
+                (uint256(uint8(revertData[2])) << 8) |
+                uint256(uint8(revertData[3]))
+        );
+
+        return errorSelector;
+    }
+
+    function extractErrorString(bytes memory revertData) internal returns (bytes32) {
+        if (revertData.length < 68) revert();
+        assembly {
+            revertData := add(revertData, 0x04)
+        }
+        return keccak256(abi.encodePacked(abi.decode(revertData, (string))));
+    }
+
+    function selectorToUint(bytes4 selector) internal returns (uint256) {
+        return uint256(uint32(selector));
+    }
+
+    function assertWithMsg(bool b, string memory reason) internal {
+        if (!b) {
+            emit AssertFail(reason);
+            assert(false);
+        }
+    }
+
+    function minUint8(uint8 a, uint8 b) internal returns (uint8) {
+        return a < b ? a : b;
+    }
+
+    function minUint256(uint256 a, uint256 b) internal returns (uint256) {
+        return a < b ? a : b;
+    }
+}

evm/echidna/helpers/IHevm.sol

@@ -0,0 +1,7 @@
+pragma solidity >=0.8.8 <0.9.0;
+
+interface IHevm {
+    function prank(address) external;
+
+    function warp(uint256 newTimestamp) external;
+}