assets: Add shared asset tooling

assets/deposit/boundary_test.go

@@ -0,0 +1,143 @@
+package deposit
+
+import (
+	"bytes"
+	"context"
+	"testing"
+
+	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/lightninglabs/taproot-assets/address"
+	"github.com/lightninglabs/taproot-assets/asset"
+	"github.com/lightninglabs/taproot-assets/proof"
+	"github.com/lightninglabs/taproot-assets/taprpc"
+	"github.com/lightningnetwork/lnd/keychain"
+	"github.com/lightningnetwork/lnd/lntypes"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/grpc"
+)
+
+// TestNewKitRejectsOppositeKeys ensures the two script roles cannot use the
+// same x-only key under different compressed encodings.
+func TestNewKitRejectsOppositeKeys(t *testing.T) {
+	_, funder := scalarKey(t, 1)
+	encoded := funder.SerializeCompressed()
+	encoded[0] ^= 1
+	opposite, err := btcec.ParsePubKey(encoded)
+	require.NoError(t, err)
+	require.False(t, funder.IsEqual(opposite))
+
+	_, err = NewKit(
+		funder, opposite, keychain.KeyLocator{}, asset.ID{1}, 144,
+		&address.RegressionNetTap,
+	)
+	require.ErrorContains(t, err, "keys must differ")
+}
+
+// mutatingAddressClient retains and modifies request IDs to exercise the
+// ownership boundary between a kit and its RPC client.
+type mutatingAddressClient struct {
+	ids [][]byte
+}
+
+// NewAddr retains and mutates the request's asset ID.
+func (m *mutatingAddressClient) NewAddr(_ context.Context,
+	req *taprpc.NewAddrRequest, _ ...grpc.CallOption) (*taprpc.Addr, error) {
+
+	m.ids = append(m.ids, req.AssetId)
+	req.AssetId[0] ^= 1
+
+	return &taprpc.Addr{}, nil
+}
+
+// ExportProof retains and mutates the request's asset ID.
+func (m *mutatingAddressClient) ExportProof(_ context.Context,
+	req *taprpc.ExportProofRequest, _ ...grpc.CallOption) (*taprpc.ProofFile,
+	error) {
+
+	m.ids = append(m.ids, req.AssetId)
+	req.AssetId[0] ^= 1
+
+	return &taprpc.ProofFile{}, nil
+}
+
+// TestRPCRequestsPreserveAssetID verifies that immediate and retained request
+// mutations cannot change a kit or a derived HTLC contract.
+func TestRPCRequestsPreserveAssetID(t *testing.T) {
+	fixture := newWitnessFixture(t)
+	kit := fixture.kit
+	expectedID := kit.assetID
+	client := &mutatingAddressClient{}
+
+	_, err := kit.NewAddr(t.Context(), client, 1000)
+	require.NoError(t, err)
+	require.Equal(t, expectedID, kit.assetID)
+
+	_, swapKit, err := kit.NewHtlcAddr(
+		t.Context(), client, 1000, lntypes.Hash{1}, 144,
+	)
+	require.NoError(t, err)
+	require.Equal(t, expectedID, kit.assetID)
+	require.Equal(t, expectedID, swapKit.AssetID())
+
+	outpoint := fixture.proof.OutPoint()
+	_, err = kit.ExportProof(t.Context(), client, &outpoint)
+	require.NoError(t, err)
+	require.Equal(t, expectedID, kit.assetID)
+	require.Len(t, client.ids, 3)
+	for _, id := range client.ids {
+		clear(id)
+	}
+	require.Equal(t, expectedID, kit.assetID)
+	_, err = kit.AnchorRootFromProofCommitment(fixture.proof, 1000)
+	require.NoError(t, err)
+}
+
+// TestVerifyProofFileSnapshot verifies that changes to caller-owned bytes
+// during the RPC cannot replace the proof consumed after verification.
+func TestVerifyProofFileSnapshot(t *testing.T) {
+	fixture := newWitnessFixture(t)
+	file, err := proof.NewFile(proof.V0, *fixture.proof)
+	require.NoError(t, err)
+	var encoded bytes.Buffer
+	require.NoError(t, file.Encode(&encoded))
+	raw := encoded.Bytes()
+	expectedBytes := bytes.Clone(raw)
+	rpcFile := &taprpc.ProofFile{RawProofFile: raw}
+	outpoint := fixture.proof.OutPoint()
+	verifier := &proofVerifierMock{
+		response: &taprpc.VerifyProofResponse{Valid: true},
+		onVerify: func(req *taprpc.ProofFile) {
+			clear(raw)
+			rpcFile.RawProofFile = []byte{0}
+			require.Equal(t, expectedBytes, req.RawProofFile)
+		},
+	}
+	expectedRoot, err := fixture.kit.AnchorRootFromProofCommitment(
+		fixture.proof, fixture.proof.Asset.Amount,
+	)
+	require.NoError(t, err)
+	root, err := fixture.kit.VerifyProofFile(
+		t.Context(), verifier, rpcFile, &outpoint,
+		fixture.proof.Asset.Amount,
+	)
+	require.NoError(t, err)
+	require.Equal(t, expectedRoot, root)
+	require.Equal(t, 1, verifier.calls)
+}
+
+// TestVerifyProofFileSizeLimit verifies oversized input is rejected before
+// crossing the verifier boundary.
+func TestVerifyProofFileSizeLimit(t *testing.T) {
+	fixture := newWitnessFixture(t)
+	verifier := &proofVerifierMock{
+		response: &taprpc.VerifyProofResponse{Valid: true},
+	}
+	_, err := fixture.kit.VerifyProofFile(
+		t.Context(), verifier, &taprpc.ProofFile{
+			RawProofFile: make([]byte, proof.FileMaxProofSizeBytes+1),
+		}, &wire.OutPoint{}, fixture.proof.Asset.Amount,
+	)
+	require.ErrorContains(t, err, "file exceeds maximum size")
+	require.Zero(t, verifier.calls)
+}

assets/deposit/doc.go

@@ -0,0 +1,5 @@
+// Package deposit contains the legacy Taproot Asset deposit contract used by
+// the Loop integration environment. It owns deposit address construction,
+// proof validation, and the unilateral timeout path. Asset HTLC construction
+// remains in the sibling htlc package.
+package deposit