### Please describe the problem.
Bad input data given to gpg will make it lock.

### What steps will reproduce the problem?
Trying to download gpg encrypted data from remote with bad/incorrect data

### What version of git-annex are you using? On what operating system?
4.20130501-gd9e288b, on ubuntu 13.04

### Please provide any additional information below.
Transcript
http://paste.ubuntu.com/5626517/

Note: The problem is most likely caused by bad data from either the nntp hooks program, or the nntp server itself.

I also have one file with bad data that consistently is NOT a problem for gpg to handle(lines 24-25 of log).
