  We calculate fluctuation corrections to the longitudinal conductivity of
disordered superconductors subject to an external magnetic field. We derive
analytic expressions that are valid in the entire metallic part of the
temperature-magnetic field phase diagram as long as the effect of the magnetic
field on the spin degrees of freedom of the electrons may be neglected. Our
calculations are based on a kinetic equation approach. For the special case of
superconducting films and wires in parallel magnetic fields we perform a
detailed comparison with results that were previously obtained with
diagrammatic perturbation theory in the imaginary time formalism. As an
application, we study the fluctuation conductivity of films in tilted magnetic
fields with a special focus on the low-temperature regime. We present a
detailed discussion of the phenomenon of the non-monotonous magnetoresistance
and find that it displays a pronounced dependence on the tilting angle.
