1 files changed, 41 insertions, 0 deletions
diff --git a/cmd/sigsum-debug/head/sign/sign.go b/cmd/sigsum-debug/head/sign/sign.go
new file mode 100644
index 0000000..572af9a
--- /dev/null
+++ b/cmd/sigsum-debug/head/sign/sign.go
@@ -0,0 +1,41 @@
+package sign
+
+import (
+	"bytes"
+	"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, optPrivateKey, optKeyHash string) error {
+	if len(args) != 0 {
+		return fmt.Errorf("trailing arguments: %s", strings.Join(args, ", "))
+	}
+	b, err := fmtio.BytesFromStdin()
+	if err != nil {
+		return fmt.Errorf("read stdin: %w", err)
+	}
+	priv, err := fmtio.SignerFromHex(optPrivateKey)
+	if err != nil {
+		return fmt.Errorf("parse private key: %v", err)
+	}
+	keyHash, err := fmtio.KeyHashFromHex(optKeyHash)
+	if err != nil {
+		return fmt.Errorf("parse key hash: %v", err)
+	}
+
+	var input types.SignedTreeHead
+	if err := input.FromASCII(bytes.NewBuffer(b)); err != nil {
+		return fmt.Errorf("parse signed tree head: %v", err)
+	}
+	output, err := input.TreeHead.Sign(priv, &keyHash)
+	if err != nil {
+		return fmt.Errorf("sign tree head: %v", err)
+	}
+
+	fmt.Printf("%s\n", hex.Serialize(output.Signature[:]))
+	return nil
+}