Xcode produces an SSL error when attempting to upload app to App Store
I had the same error message and I tried using Application Loader, double checking password and account information, logging in via Safari, quitting Safari, etc. What eventually worked for me was simply restarting my computer.
Very frustrating, but hopefully this helps someone else save 15 minutes of time.
Restarting Xcode worked for me. Hooray!
When this didn't work, restarting my computer worked. Hooray!
Try turning Wifi off and on again. This should get you a new internet connection.