master -> develop (#20)

* Squash merge develop into master

* feat: add automated production release workflow

* feat: add Gitflow workflow for syncing branches

* ci: update workflow runner to latest ubuntu version

* feat: enable buf.build publishing on master and develop branches

---------

Co-authored-by: Prad Nukala <prad@sonr.io>

x/did/builder/signer.go

@@ -0,0 +1,59 @@
+package builder
+
+import (
+	"github.com/onsonr/crypto"
+	"github.com/onsonr/sonr/x/did/types"
+)
+
+type Signer interface {
+	Sign(msg []byte) ([]byte, error)
+	Verify(msg []byte, sig []byte) error
+	PublicKey() []byte
+}
+
+type signer struct {
+	user *types.Keyshare
+	val  *types.Keyshare
+}
+
+func (k signer) Sign(msg []byte) ([]byte, error) {
+	valSignFunc, err := crypto.GetSignFunc(k.val, msg)
+	if err != nil {
+		return nil, err
+	}
+	usrSignFunc, err := crypto.GetSignFunc(k.user, msg)
+	if err != nil {
+		return nil, err
+	}
+	sig, err := crypto.RunMPCSign(valSignFunc, usrSignFunc)
+	if err != nil {
+		return nil, err
+	}
+	return crypto.SerializeMPCSignature(sig)
+}
+
+func (k signer) Verify(msg []byte, sig []byte) error {
+	sigMpc, err := crypto.DeserializeMPCSignature(sig)
+	if err != nil {
+		return err
+	}
+	pk, err := crypto.GetECDSAPublicKey(k.val)
+	if err != nil {
+		return err
+	}
+	ok := crypto.VerifyMPCSignature(sigMpc, msg, pk)
+	if !ok {
+		return types.ErrInvalidSignature
+	}
+	return nil
+}
+
+func (k signer) PublicKey() []byte {
+	if k.user != nil {
+		return k.user.PublicKey
+	}
+	if k.val != nil {
+		return k.val.PublicKey
+	}
+	return nil
+}