1 files changed, 99 insertions, 0 deletions
diff --git a/trillian/client.go b/trillian/client.go
new file mode 100644
index 0000000..c22e9cc
--- /dev/null
+++ b/trillian/client.go
@@ -0,0 +1,99 @@
+package trillian
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/golang/glog"
+	"github.com/google/trillian"
+	ttypes "github.com/google/trillian/types"
+	"github.com/system-transparency/stfe/types"
+	"google.golang.org/grpc/codes"
+)
+
+// Client is a wrapper around the Trillian gRPC client
+type Client struct {
+	// TreeID is a Merkle tree identifier that Trillian uses
+	TreeID int64
+
+	// GRPC is a Trillian gRPC client
+	GRPC trillian.TrillianLogClient
+}
+
+func (c *Client) 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 *Client) 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))
+	}
+
+	var hash [types.HashSize]byte
+	th := types.TreeHead{
+		Timestamp: uint64(r.TimestampNanos / 1000 / 1000 / 1000),
+		TreeSize:  uint64(r.TreeSize),
+		RootHash:  &hash,
+	}
+	copy(th.RootHash[:], r.RootHash)
+	return &th, nil
+}
+
+func (c *Client) GetConsistencyProof(ctx context.Context, req *types.ConsistencyProofRequest) (*types.ConsistencyProof, error) {
+	return nil, fmt.Errorf("TODO")
+}
+
+func (c *Client) GetInclusionProof(ctx context.Context, req *types.InclusionProofRequest) (*types.InclusionProof, error) {
+	return nil, fmt.Errorf("TODO")
+}
+
+func (c *Client) GetLeaves(ctx context.Context, req *types.LeavesRequest) (*types.LeafList, error) {
+	return nil, fmt.Errorf("TODO")
+}