Description of problem:
Certtool generates x509 keys with negative modulus, please read this conversation: http://code.google.com/p/go/issues/detail?id=6837&q=gnutls&colspec=ID%20Status%20Stars%20Priority%20Owner%20Reporter%20Summary
Version-Release number of selected component (if applicable):
CentOS release 6.4 (Final)
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.