Store only the seed of the private key

2 files changed, 3 insertions, 3 deletions

diff --git a/cmd/sigsum-debug/key/private/private.go b/cmd/sigsum-debug/key/private/private.go
index 3928f56..70779c2 100644
--- a/cmd/sigsum-debug/key/private/private.go
+++ b/cmd/sigsum-debug/key/private/private.go
@@ -24,6 +24,6 @@ func Main(args []string) error {
 		return fmt.Errorf("invalid key size %d", len(priv))
 	}
 
-	fmt.Printf("%s\n", hex.Serialize(priv[:]))
+	fmt.Printf("%s\n", hex.Serialize(priv.Seed()))
 	return nil
 }
diff --git a/internal/fmtio/fmtio.go b/internal/fmtio/fmtio.go
index 0e252d4..f900e42 100644
--- a/internal/fmtio/fmtio.go
+++ b/internal/fmtio/fmtio.go
@@ -36,10 +36,10 @@ func SignerFromHex(s string) (crypto.Signer, error) {
 	if err != nil {
 		return nil, err
 	}
-	if n := len(b); n != ed25519.PrivateKeySize {
+	if n := len(b); n != ed25519.SeedSize {
 		return nil, fmt.Errorf("invalid size %d", n)
 	}
-	return ed25519.PrivateKey(b), nil
+	return ed25519.NewKeyFromSeed(b), nil
 }
 
 func PublicKeyFromHex(s string) (pub types.PublicKey, err error) {