  We study chiral symmetry breaking using the quark gap equation supplemented
with the infrared-finite gluon propagator and ghost dressing function obtained
from large-volume lattice simulations. One of the most important ingredients of
this analysis is the non-Abelian quark-gluon vertex, which displays a crucial
dependence on the ghost dressing function and the quark-ghost scattering
amplitude. The various theoretical ingredients necessary for this construction
are reviewed in detail. As a result, we obtain a dynamical quark masses of the
order of 300 MeV, which is used to compute phenomenological parameters such as
the pion decay constant and the quark condensate.
