feat: add avail attestation contract

src/AvailAttestation.sol

@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity ^0.8.25;
+
+import {Initializable} from "lib/openzeppelin-contracts-upgradeable/contracts/proxy/utils/Initializable.sol";
+import {IVectorx} from "src/interfaces/IVectorx.sol";
+import {IAvailBridge} from "src/interfaces/IAvailBridge.sol";
+
+/**
+ * @author  @QEDK (Avail)
+ * @title   AvailAttestation
+ * @notice  An abstract data attestation implementation for validiums, optimiums and generic rollup stacks
+ * @custom:security security@availproject.org
+ */
+abstract contract AvailAttestation is Initializable {
+    struct AttestationData {
+        uint32 blockNumber;
+        uint128 leafIndex;
+    }
+
+    IAvailBridge public bridge;
+    IVectorx public vectorx;
+
+    mapping (bytes32 => AttestationData) public attestations;
+
+    error InvalidAttestationProof();
+    event Attested(bytes32 indexed leaf, uint32 indexed blockNumber, uint128 indexed leafIndex);
+
+    function initialize(IAvailBridge _bridge) external initializer {
+        bridge = _bridge;
+        vectorx = bridge.vectorx();
+    }
+
+    function _attest(IAvailBridge.MerkleProofInput calldata input) external {
+        if (!bridge.verifyBlobLeaf(input)) revert InvalidAttestationProof();
+        attestations[input.leaf] = AttestationData(
+            vectorx.rangeStartBlocks(input.rangeHash) + uint32(input.dataRootIndex),
+            uint128(input.leafIndex)
+        );
+    }
+}

src/interfaces/IAvailBridge.sol

@@ -61,6 +61,7 @@ interface IAvailBridge {
     error UnlockFailed();
     error WithdrawFailed();
 
+    function vectorx() external view returns (IVectorx);
     function setPaused(bool status) external;
     function updateVectorx(IVectorx newVectorx) external;
     function updateTokens(bytes32[] calldata assetIds, address[] calldata tokenAddresses) external;

src/interfaces/IVectorx.sol

@@ -3,4 +3,5 @@ pragma solidity ^0.8.25;
 
 interface IVectorx {
     function dataRootCommitments(bytes32 rangeHash) external view returns (bytes32 dataRoot);
+    function rangeStartBlocks(bytes32 rangeHash) external view returns (uint32 startBlock);
 }

src/mocks/VectorxMock.sol

@@ -5,8 +5,13 @@ import {IVectorx} from "src/interfaces/IVectorx.sol";
 
 contract VectorxMock is IVectorx {
     mapping(bytes32 => bytes32) public dataRootCommitments;
+    mapping(bytes32 => uint32) public rangeStartBlocks;
 
     function set(bytes32 rangeHash, bytes32 dataRoot) external {
         dataRootCommitments[rangeHash] = dataRoot;
     }
+
+    function setStartBlock(bytes32 rangeHash, uint32 startBlock) external {
+        rangeStartBlocks[rangeHash] = startBlock;
+    }
 }