At present, we have adopted Shibboleth to access the third-party SSO, but we still need to adopt Shibboleth to access edugain authentication. I wonder whether indico supports Shibboleth to access two third-party authentication?
Yes, you can use Shibboleth. Authentication — Indico 3.2 documentation
Maybe I didn’t make it clear. We have opened Shibboleth authentication for the unified internal authentication account to log in indico, can it be used to access edugain?
Yes, it should be possible. But I’m afraid we cannot help you with setting it up since that’s happening outside Indico - it’s more about configuring Shibboleth properly.