Merge pull request #967 from f1d094/master

Modify ISAPI to reliably open connections

pkg/isapi/client.go

@@ -84,8 +84,17 @@ func (c *Client) Dial() (err error) {
 }
 
 func (c *Client) Open() (err error) {
-	link := c.url + "/ISAPI/System/TwoWayAudio/channels/" + c.channel
+   // Hikvision ISAPI may not accept a new open request if the previous one was not closed (e.g.
+   // using the test button on-camera or via curl command) but a close request can be sent even if
+   // the audio is already closed. So, we send a close request first and then open it again. Seems
+   // janky but it works.
+
+   err = c.Close()
+   if err != nil {
+      return err
+   }
 
+	link := c.url + "/ISAPI/System/TwoWayAudio/channels/" + c.channel
 	req, err := http.NewRequest("PUT", link+"/open", nil)
 	if err != nil {
 		return err
@@ -124,8 +133,8 @@ func (c *Client) Open() (err error) {
 }
 
 func (c *Client) Close() (err error) {
-	link := c.url + "/ISAPI/System/TwoWayAudio/channels/" + c.channel + "/close"
-	req, err := http.NewRequest("PUT", link+"/open", nil)
+	link := c.url + "/ISAPI/System/TwoWayAudio/channels/" + c.channel
+	req, err := http.NewRequest("PUT", link+"/close", nil)
 	if err != nil {
 		return err
 	}

pkg/tcp/request.go

@@ -115,7 +115,9 @@ func Do(req *http.Request) (*http.Response, error) {
 			)
 		case "auth":
 			nc := "00000001"
-			cnonce := "00000001" // TODO: random...
+			// TODO: Random cnonce
+         // Here is temp static cnonce of required 32 bytes
+			cnonce := "ZDlmODczZTk2NjQyZTQ4OGQ5ZGEzOTI3YTc5Y2Q0ZGM="
 			response := HexMD5(ha1, nonce, nc, cnonce, qop, ha2)
 			header = fmt.Sprintf(
 				`Digest username="%s", realm="%s", nonce="%s", uri="%s", qop=%s, nc=%s, cnonce="%s", response="%s"`,