1 files changed, 178 insertions, 0 deletions
diff --git a/pkg/trillian/client.go b/pkg/trillian/client.go
new file mode 100644
index 0000000..9523e56
--- /dev/null
+++ b/pkg/trillian/client.go
@@ -0,0 +1,178 @@
+package trillian
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/golang/glog"
+	"github.com/google/trillian"
+	ttypes "github.com/google/trillian/types"
+	"github.com/system-transparency/stfe/pkg/types"
+	"google.golang.org/grpc/codes"
+)
+
+type Client interface {
+	AddLeaf(context.Context, *types.LeafRequest) error
+	GetConsistencyProof(context.Context, *types.ConsistencyProofRequest) (*types.ConsistencyProof, error)
+	GetTreeHead(context.Context) (*types.TreeHead, error)
+	GetInclusionProof(context.Context, *types.InclusionProofRequest) (*types.InclusionProof, error)
+	GetLeaves(context.Context, *types.LeavesRequest) (*types.LeafList, error)
+}
+
+// TrillianClient is a wrapper around the Trillian gRPC client.
+type TrillianClient struct {
+	// TreeID is a Merkle tree identifier that Trillian uses
+	TreeID int64
+
+	// GRPC is a Trillian gRPC client
+	GRPC trillian.TrillianLogClient
+}
+
+func (c *TrillianClient) AddLeaf(ctx context.Context, req *types.LeafRequest) error {
+	leaf := types.Leaf{
+		Message: req.Message,
+		SigIdent: types.SigIdent{
+			Signature: req.Signature,
+			KeyHash:   types.Hash(req.VerificationKey[:]),
+		},
+	}
+	serialized := leaf.Marshal()
+
+	glog.V(3).Infof("queueing leaf request: %x", types.HashLeaf(serialized))
+	rsp, err := c.GRPC.QueueLeaf(ctx, &trillian.QueueLeafRequest{
+		LogId: c.TreeID,
+		Leaf: &trillian.LogLeaf{
+			LeafValue: serialized,
+		},
+	})
+	if err != nil {
+		return fmt.Errorf("backend failure: %v", err)
+	}
+	if rsp == nil {
+		return fmt.Errorf("no response")
+	}
+	if rsp.QueuedLeaf == nil {
+		return fmt.Errorf("no queued leaf")
+	}
+	if codes.Code(rsp.QueuedLeaf.GetStatus().GetCode()) == codes.AlreadyExists {
+		return fmt.Errorf("leaf is already queued or included")
+	}
+	return nil
+}
+
+func (c *TrillianClient) GetTreeHead(ctx context.Context) (*types.TreeHead, error) {
+	rsp, err := c.GRPC.GetLatestSignedLogRoot(ctx, &trillian.GetLatestSignedLogRootRequest{
+		LogId: c.TreeID,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("backend failure: %v", err)
+	}
+	if rsp == nil {
+		return nil, fmt.Errorf("no response")
+	}
+	if rsp.SignedLogRoot == nil {
+		return nil, fmt.Errorf("no signed log root")
+	}
+	if rsp.SignedLogRoot.LogRoot == nil {
+		return nil, fmt.Errorf("no log root")
+	}
+	var r ttypes.LogRootV1
+	if err := r.UnmarshalBinary(rsp.SignedLogRoot.LogRoot); err != nil {
+		return nil, fmt.Errorf("no log root: unmarshal failed: %v", err)
+	}
+	if len(r.RootHash) != types.HashSize {
+		return nil, fmt.Errorf("unexpected hash length: %d", len(r.RootHash))
+	}
+	return treeHeadFromLogRoot(&r), nil
+}
+
+func (c *TrillianClient) GetConsistencyProof(ctx context.Context, req *types.ConsistencyProofRequest) (*types.ConsistencyProof, error) {
+	rsp, err := c.GRPC.GetConsistencyProof(ctx, &trillian.GetConsistencyProofRequest{
+		LogId:          c.TreeID,
+		FirstTreeSize:  int64(req.OldSize),
+		SecondTreeSize: int64(req.NewSize),
+	})
+	if err != nil {
+		return nil, fmt.Errorf("backend failure: %v", err)
+	}
+	if rsp == nil {
+		return nil, fmt.Errorf("no response")
+	}
+	if rsp.Proof == nil {
+		return nil, fmt.Errorf("no consistency proof")
+	}
+	if len(rsp.Proof.Hashes) == 0 {
+		return nil, fmt.Errorf("not a consistency proof: empty")
+	}
+	path, err := nodePathFromHashes(rsp.Proof.Hashes)
+	if err != nil {
+		return nil, fmt.Errorf("not a consistency proof: %v", err)
+	}
+	return &types.ConsistencyProof{
+		OldSize: req.OldSize,
+		NewSize: req.NewSize,
+		Path:    path,
+	}, nil
+}
+
+func (c *TrillianClient) GetInclusionProof(ctx context.Context, req *types.InclusionProofRequest) (*types.InclusionProof, error) {
+	rsp, err := c.GRPC.GetInclusionProofByHash(ctx, &trillian.GetInclusionProofByHashRequest{
+		LogId:           c.TreeID,
+		LeafHash:        req.LeafHash[:],
+		TreeSize:        int64(req.TreeSize),
+		OrderBySequence: true,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("backend failure: %v", err)
+	}
+	if rsp == nil {
+		return nil, fmt.Errorf("no response")
+	}
+	if len(rsp.Proof) != 1 {
+		return nil, fmt.Errorf("bad proof count: %d", len(rsp.Proof))
+	}
+	proof := rsp.Proof[0]
+	if len(proof.Hashes) == 0 {
+		return nil, fmt.Errorf("not an inclusion proof: empty")
+	}
+	path, err := nodePathFromHashes(proof.Hashes)
+	if err != nil {
+		return nil, fmt.Errorf("not an inclusion proof: %v", err)
+	}
+	return &types.InclusionProof{
+		TreeSize:  req.TreeSize,
+		LeafIndex: uint64(proof.LeafIndex),
+		Path:      path,
+	}, nil
+}
+
+func (c *TrillianClient) GetLeaves(ctx context.Context, req *types.LeavesRequest) (*types.LeafList, error) {
+	rsp, err := c.GRPC.GetLeavesByRange(ctx, &trillian.GetLeavesByRangeRequest{
+		LogId:      c.TreeID,
+		StartIndex: int64(req.StartSize),
+		Count:      int64(req.EndSize-req.StartSize) + 1,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("backend failure: %v", err)
+	}
+	if rsp == nil {
+		return nil, fmt.Errorf("no response")
+	}
+	if got, want := len(rsp.Leaves), int(req.EndSize-req.StartSize+1); got != want {
+		return nil, fmt.Errorf("unexpected number of leaves: %d", got)
+	}
+	var list types.LeafList
+	for i, leaf := range rsp.Leaves {
+		leafIndex := int64(req.StartSize + uint64(i))
+		if leafIndex != leaf.LeafIndex {
+			return nil, fmt.Errorf("unexpected leaf(%d): got index %d", leafIndex, leaf.LeafIndex)
+		}
+
+		var l types.Leaf
+		if err := l.Unmarshal(leaf.LeafValue); err != nil {
+			return nil, fmt.Errorf("unexpected leaf(%d): %v", leafIndex, err)
+		}
+		list = append(list[:], &l)
+	}
+	return &list, nil
+}