  Electroweak baryogenesis provides an attractive explanation of the origin of
the matter-antimatter asymmetry that relies on physics at the weak scale and
thus it is testable at present and near future high-energy physics experiments.
Although this scenario may not be realized within the Standard Model, it can be
accommodated within the MSSM provided there are new CP-violating phases and the
lightest stop mass is smaller than the top-quark mass. In this work we provide
an evaluation of the values of the stop (m_{\tilde t}) and Higgs (m_H) masses
consistent with the requirements of electroweak baryogenesis based on an
analysis that makes use of the renormalization group improved Higgs and stop
potentials, and including the dominant two-loop effects at high temperature. We
find an allowed window in the (m_{\tilde t},m_H)-plane, consistent with all
present experimental data, where there is a strongly first-order electroweak
phase transition and where the electroweak vacuum is metastable but
sufficiently long-lived. In particular we obtain absolute upper bounds on the
Higgs and stop masses, m_H\lesssim 127 GeV and m_{\tilde t}\lesssim 120 GeV,
implying that this scenario will be probed at the LHC.
