  We propose a method to distinguish between trivial and topological, Majorana,
zero-energy states in both short and long superconductor-normal-superconductor
junctions based on Rashba nanowires using phase-biased equilibrium transport
measurements. In particular, we show how the sawtooth profile of the
supercurrent, due to the Majorana oscillation suppression in the topological
phase for sufficiently long superconductor regions, leads to a strong signal in
its zero-frequency susceptibility for a phase difference of $\phi=\pi$. This
signal is notably insensitive to the chemical potential in the normal region,
while trivial zero-energy states only causes signals in the susceptibility that
is highly varying with the chemical potential, thus turning gating of the
normal region into a simple experimental control knob. Furthermore, we obtain
that, by tuning the junction transparency, critical currents in both short and
long junctions undergo a reduction in the number of oscillations as a function
of magnetic field only in the topological phase, an effect that find to be
intimately linked to Majorana non-locality. Finally, we show that our results
also hold at finite temperatures, thus highlighting their potential
measurability under realistic experimental conditions.
