1 files changed, 42 insertions, 0 deletions
diff --git a/cmd/sigsum-debug/leaf/hash/hash.go b/cmd/sigsum-debug/leaf/hash/hash.go
new file mode 100644
index 0000000..9bc845e
--- /dev/null
+++ b/cmd/sigsum-debug/leaf/hash/hash.go
@@ -0,0 +1,42 @@
+package hash
+
+import (
+	"fmt"
+	"strings"
+
+	"git.sigsum.org/sigsum-go/internal/fmtio"
+	"git.sigsum.org/sigsum-go/pkg/hex"
+	"git.sigsum.org/sigsum-go/pkg/types"
+)
+
+func Main(args []string, optKeyHash, optSignature string, optShardHint uint64) error {
+	if len(args) != 0 {
+		return fmt.Errorf("trailing arguments: %s", strings.Join(args, ", "))
+	}
+	data, err := fmtio.BytesFromStdin()
+	if err != nil {
+		return fmt.Errorf("read stdin: %w", err)
+	}
+	keyHash, err := fmtio.KeyHashFromHex(optKeyHash)
+	if err != nil {
+		return fmt.Errorf("parse key hash: %w", err)
+	}
+	sig, err := fmtio.SignatureFromHex(optSignature)
+	if err != nil {
+		return fmt.Errorf("parse signature: %w", err)
+	}
+
+	preimage := types.HashFn(data)
+	leaf := types.Leaf{
+		Statement: types.Statement{
+			ShardHint: optShardHint,
+			Checksum:  *types.HashFn(preimage[:]),
+		},
+		Signature: sig,
+		KeyHash:   keyHash,
+	}
+	leafHash := types.LeafHash(leaf.ToBinary())
+
+	fmt.Printf("%s\n", hex.Serialize(leafHash[:]))
+	return nil
+}