WIP: extend proof block header verifier to account for block height

itest/assertions.go

@@ -265,14 +265,42 @@ func verifyProofBlob(t *testing.T, tapd *tapdHarness,
 	anchorTxBlockHeight := rpcAsset.ChainAnchor.BlockHeight
 	require.Greater(t, anchorTxBlockHeight, uint32(0))
 
-	headerVerifier := func(blockHeader wire.BlockHeader) error {
-		hash := blockHeader.BlockHash()
+	headerVerifier := func(header wire.BlockHeader, height uint32) error {
+		hash := header.BlockHash()
 		req := &chainrpc.GetBlockRequest{
 			BlockHash: hash.CloneBytes(),
 		}
 		_, err := tapd.cfg.LndNode.RPC.ChainKit.GetBlock(ctxb, req)
-		return err
+		if err != nil {
+			return err
+		}
+
+		//// Ensure that the block hash matches the hash of the block
+		//// found at the given height.
+		//blockHashReq := &chainrpc.GetBlockHashRequest{
+		//	BlockHeight: int64(height),
+		//}
+		//blockHashResp, err := tapd.cfg.LndNode.RPC.ChainKit.GetBlockHash(
+		//	ctxb, blockHashReq,
+		//)
+		//if err != nil {
+		//	return err
+		//}
+		//
+		//var heightHash chainhash.Hash
+		//copy(heightHash[:], blockHashResp.BlockHash)
+		//
+		//expectedHash := hash
+		//if heightHash != expectedHash {
+		//	return fmt.Errorf("block hash and block height "+
+		//		"mismatch; (height: %x, hashAtHeight: %x, "+
+		//		"expectedHash: %x)", height, heightHash,
+		//		expectedHash)
+		//}
+
+		return nil
 	}
+
 	snapshot, err := f.Verify(ctxt, headerVerifier)
 	require.NoError(t, err)
 

proof/mock.go

@@ -39,6 +39,6 @@ func (m *MockVerifier) Verify(_ context.Context, _ io.Reader,
 // Header verification usually involves cross-referencing with chain data.
 // Chain data is not available in unit tests. This function is useful for unit
 // tests which are not primarily concerned with block header verification.
-func MockHeaderVerifier(blockHeader wire.BlockHeader) error {
+func MockHeaderVerifier(header wire.BlockHeader, height uint32) error {
 	return nil
 }

proof/proof_test.go

@@ -487,10 +487,10 @@ func TestProofBlockHeaderVerification(t *testing.T) {
 	// Header verifier compares given header to expected header. Verifier
 	// does not return error.
 	errHeaderVerifier := fmt.Errorf("invalid block header")
-	headerVerifier := func(blockHeader wire.BlockHeader) error {
+	headerVerifier := func(header wire.BlockHeader, height uint32) error {
 		// Compare given block header against base reference block
 		// header.
-		if blockHeader != originalBlockHeader {
+		if header != originalBlockHeader {
 			return errHeaderVerifier
 		}
 		return nil

proof/verifier.go

@@ -288,7 +288,7 @@ func (p *Proof) verifyMetaReveal() error {
 
 // HeaderVerifier is a callback function which returns an error if the given
 // block header is invalid (usually: not present on chain).
-type HeaderVerifier func(blockHeader wire.BlockHeader) error
+type HeaderVerifier func(blockHeader wire.BlockHeader, blockHeight uint32) error
 
 // Verify verifies the proof by ensuring that:
 //
@@ -313,7 +313,7 @@ func (p *Proof) Verify(ctx context.Context, prev *AssetSnapshot,
 	}
 
 	// Cross-check block header with a bitcoin node.
-	err := headerVerifier(p.BlockHeader)
+	err := headerVerifier(p.BlockHeader, p.BlockHeight)
 	if err != nil {
 		return nil, fmt.Errorf("failed to validate proof block "+
 			"header: %w", err)

tapgarden/caretaker.go

@@ -1025,12 +1025,32 @@ func GetTxFee(pkt *psbt.Packet) (int64, error) {
 // GenHeaderVerifier generates a block header on-chain verification callback
 // function given a chain bridge.
 func GenHeaderVerifier(ctx context.Context,
-	chainBridge ChainBridge) func(header wire.BlockHeader) error {
+	chainBridge ChainBridge) func(wire.BlockHeader, uint32) error {
 
-	return func(blockHeader wire.BlockHeader) error {
+	return func(header wire.BlockHeader, height uint32) error {
 		_, err := chainBridge.GetBlock(
-			ctx, blockHeader.BlockHash(),
+			ctx, header.BlockHash(),
 		)
-		return err
+		if err != nil {
+			return err
+		}
+
+		// Ensure that the block hash matches the hash of the block
+		// found at the given height.
+		hash, err := chainBridge.GetBlockHash(
+			ctx, int64(height),
+		)
+		if err != nil {
+			return err
+		}
+
+		expectedHash := header.BlockHash()
+		if hash != expectedHash {
+			return fmt.Errorf("block hash and block height "+
+				"mismatch; (height: %x, hashAtHeight: %x, "+
+				"expectedHash: %x)", height, hash, expectedHash)
+		}
+
+		return nil
 	}
 }