Connector: check len(values) to avoid nil pointer dereference (#21)

connector/http.go

@@ -2,6 +2,7 @@ package connector
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -10,6 +11,8 @@ import (
 	"github.com/certusone/yubihsm-go/commands"
 )
 
+var ErrInvalidResponseValueLength = errors.New("invalid response value length")
+
 type (
 	// HTTPConnector implements the HTTP based connection with the YubiHSM2 connector
 	HTTPConnector struct {
@@ -77,6 +80,10 @@ func (c *HTTPConnector) GetStatus() (status *StatusResponse, err error) {
 		values = append(values, strings.Split(pair, "=")...)
 	}
 
+	if values == nil || len(values) < 12 {
+		return nil, ErrInvalidResponseValueLength
+	}
+
 	status = &StatusResponse{}
 	status.Status = Status(values[1])
 	status.Serial = values[3]