The DEFAULT and FUTURE levels of crypto policies don't allow AEAD ciphersuites in gnutls.
crypto-policies-20150305-1.gitf618101.fc21 has been submitted as an update for Fedora 21.
* should fix your issue,
* was pushed to the Fedora 21 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing crypto-policies-20150305-1.gitf618101.fc21'
as soon as you are able to.
Please go to the following url:
then log in and leave karma (feedback).
crypto-policies-20150305-1.gitf618101.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.