[VOL-4290] Voltha go library updates for gRPC migration

Change-Id: I1aa2774beb6b7ed7419bc45aeb53fcae8a8ecda0
diff --git a/vendor/github.com/jcmturner/gokrb5/v8/client/passwd.go b/vendor/github.com/jcmturner/gokrb5/v8/client/passwd.go
new file mode 100644
index 0000000..fe20559
--- /dev/null
+++ b/vendor/github.com/jcmturner/gokrb5/v8/client/passwd.go
@@ -0,0 +1,75 @@
+package client
+
+import (
+	"fmt"
+
+	"github.com/jcmturner/gokrb5/v8/kadmin"
+	"github.com/jcmturner/gokrb5/v8/messages"
+)
+
+// Kpasswd server response codes.
+const (
+	KRB5_KPASSWD_SUCCESS             = 0
+	KRB5_KPASSWD_MALFORMED           = 1
+	KRB5_KPASSWD_HARDERROR           = 2
+	KRB5_KPASSWD_AUTHERROR           = 3
+	KRB5_KPASSWD_SOFTERROR           = 4
+	KRB5_KPASSWD_ACCESSDENIED        = 5
+	KRB5_KPASSWD_BAD_VERSION         = 6
+	KRB5_KPASSWD_INITIAL_FLAG_NEEDED = 7
+)
+
+// ChangePasswd changes the password of the client to the value provided.
+func (cl *Client) ChangePasswd(newPasswd string) (bool, error) {
+	ASReq, err := messages.NewASReqForChgPasswd(cl.Credentials.Domain(), cl.Config, cl.Credentials.CName())
+	if err != nil {
+		return false, err
+	}
+	ASRep, err := cl.ASExchange(cl.Credentials.Domain(), ASReq, 0)
+	if err != nil {
+		return false, err
+	}
+
+	msg, key, err := kadmin.ChangePasswdMsg(cl.Credentials.CName(), cl.Credentials.Domain(), newPasswd, ASRep.Ticket, ASRep.DecryptedEncPart.Key)
+	if err != nil {
+		return false, err
+	}
+	r, err := cl.sendToKPasswd(msg)
+	if err != nil {
+		return false, err
+	}
+	err = r.Decrypt(key)
+	if err != nil {
+		return false, err
+	}
+	if r.ResultCode != KRB5_KPASSWD_SUCCESS {
+		return false, fmt.Errorf("error response from kadmin: code: %d; result: %s; krberror: %v", r.ResultCode, r.Result, r.KRBError)
+	}
+	cl.Credentials.WithPassword(newPasswd)
+	return true, nil
+}
+
+func (cl *Client) sendToKPasswd(msg kadmin.Request) (r kadmin.Reply, err error) {
+	_, kps, err := cl.Config.GetKpasswdServers(cl.Credentials.Domain(), true)
+	if err != nil {
+		return
+	}
+	b, err := msg.Marshal()
+	if err != nil {
+		return
+	}
+	var rb []byte
+	if len(b) <= cl.Config.LibDefaults.UDPPreferenceLimit {
+		rb, err = dialSendUDP(kps, b)
+		if err != nil {
+			return
+		}
+	} else {
+		rb, err = dialSendTCP(kps, b)
+		if err != nil {
+			return
+		}
+	}
+	err = r.Unmarshal(rb)
+	return
+}