A general two-dimensional solution has been obtained analytically for the crack with interating rough faces. The interaction has been modelled at a large scale as (1) Mohr-Coulomb friction and (2) the crack opening being a known function of sliding. The detailed consideration of a crack with saw-like faces has shown that the energy release rate is less than for a conventional shear crack. Tensile stress concentration caused by the crack opening reduces the angle of kinking though not sufficiently to make the crack propagate in its own plane. At a certain magnitude of shear loading the opening reaches its maximum value determined by the height of asperities. Starting from this point the zone where the maximum opening is reached rapidly increases and the dependencies of crack face displacements and the area of crack opening on the load become nonlinear. This however does not affect values of the stress intensity factors.