Added Sign method to PrivateKey

protocol/meshcore/crypto/ed25519.go

@@ -9,6 +9,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"errors"
+	"io"
 	"strconv"
 
 	"filippo.io/edwards25519"
@@ -46,6 +47,10 @@ func (priv *PrivateKey) Seed() []byte {
 	return seed[:]
 }
 
+func (priv *PrivateKey) Sign(_ io.Reader, digest []byte, _ crypto.SignerOpts) (signature []byte, err error) {
+	return Sign(priv, digest), nil
+}
+
 func (priv *PrivateKey) Public() crypto.PublicKey {
 	p := &PublicKey{}
 	newPublicKey(p, priv.pub[:])
@@ -420,4 +425,7 @@ func verifyWithDom(pub *PublicKey, message, sig []byte, domPrefix, context strin
 	return nil
 }
 
-var _ crypto.PrivateKey = (*PrivateKey)(nil)
+var (
+	_ crypto.PrivateKey = (*PrivateKey)(nil)
+	_ crypto.Signer     = (*PrivateKey)(nil)
+)