Challenge Login to Asterisk does not work

[OdinsHat]

Reported on old repo at Google

What steps will reproduce the problem?

1. Use Challenge login with Asterisk
2. Login fails

What version of the product are you using? On what operating system?
Does not matters.

Please provide any additional information below.
The issues is in AsteriskManager.php line 200
-strpos($response, "Challenge: ")));
+strpos($response, "Challenge: ")+strlen("Challenge: ")));

Otherwise the challenge is wrong and authentication fails