1 files changed, 66 insertions, 0 deletions
diff --git a/client/cmd/get-proof-by-hash/main.go b/client/cmd/get-proof-by-hash/main.go
new file mode 100644
index 0000000..1f4f304
--- /dev/null
+++ b/client/cmd/get-proof-by-hash/main.go
@@ -0,0 +1,66 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+
+	"encoding/base64"
+
+	"github.com/golang/glog"
+	"github.com/system-transparency/stfe/client"
+	"github.com/system-transparency/stfe/types"
+)
+
+var (
+	sthStr      = flag.String("sth", "", "base64-encoded StItem of type StFormatSignedTreeHeadV1 (default: fetch new sth)")
+	leafHashStr = flag.String("leaf_hash", "", "base64-encoded leaf hash")
+)
+
+func main() {
+	flag.Parse()
+	defer glog.Flush()
+
+	client, err := client.NewClientFromFlags()
+	if err != nil {
+		glog.Errorf("NewClientFromFlags: %v", err)
+		return
+	}
+	leafHash, sth, err := newParamsFromFlags(client)
+	if err != nil {
+		glog.Errorf("NewRequestFromFlags: %v", err)
+		return
+	}
+
+	proof, err := client.GetProofByHash(context.Background(), leafHash, sth)
+	if err != nil {
+		glog.Errorf("GetProofByHash: %v", err)
+		return
+	}
+	serialized, err := types.Marshal(*proof)
+	if err != nil {
+		glog.Errorf("Marshal: %v", err)
+	}
+	fmt.Println("proof:", base64.StdEncoding.EncodeToString(serialized))
+}
+
+func newParamsFromFlags(client *client.Client) ([]byte, *types.StItem, error) {
+	serialized, err := base64.StdEncoding.DecodeString(*sthStr)
+	if err != nil {
+		return nil, nil, fmt.Errorf("sth: DecodeString: %v", err)
+	}
+	var item types.StItem
+	if err = types.Unmarshal(serialized, &item); err != nil {
+		return nil, nil, fmt.Errorf("sth: Unmarshal: %v", err)
+	} else if got, want := item.Format, types.StFormatSignedTreeHeadV1; got != want {
+		return nil, nil, fmt.Errorf("unexpected StItem format: %v", got)
+	}
+	leafHash, err := base64.StdEncoding.DecodeString(*leafHashStr)
+	if err != nil {
+		return nil, nil, fmt.Errorf("leaf_hash: DecodeString: %v", err)
+	} else if got, want := len(leafHash), 32; got != want {
+		return nil, nil, fmt.Errorf("leaf_hash: unexpected size: %v", got)
+	}
+	glog.V(3).Infof("created request parameters TreeSize(%d) and LeafHash(%s)", item.SignedTreeHeadV1.TreeHead.TreeSize, *leafHashStr)
+	return leafHash, &item, nil
+}