  Magnetic fields on the order of 100 $\mu$G observed in young supernova
remnants cannot be amplified by shock compression alone. To investigate the
amplification caused by turbulent dynamo, we perform three-dimensional MHD
simulations of the interaction between shock wave and inhomogeneous density
distribution with a shallow spectrum in the preshock medium. The postshock
turbulence is mainly driven by the strongest preshock density contrast and
follows the Kolmogorov scaling. The resulting turbulence amplifies the
postshock magnetic field. The time evolution of the magnetic fields agrees with
the prediction of the nonlinear turbulent dynamo theory in Xu & Lazarian
(2016). When the initial weak magnetic field is perpendicular to the shock
normal, the maximum amplification of the field's strength achieves a factor of
$\approx200$, which is twice larger than that for a parallel shock. We find
that the perpendicular shock exhibits a smaller turbulent Alfv\'en Mach number
in the vicinity of the shock front than the parallel shock. However, the
strongest magnetic field has a low volume filling factor and is limited by the
turbulent energy due to the reconnection diffusion taking place in a turbulent
and magnetized fluid. The magnetic field strength averaged along the $z$-axis
is reduced by a factor $\gtrsim10$. We decompose the turbulent velocity and
magnetic field into solenoidal and compressive modes. The solenoidal mode is
dominant and evolves to follow the Kolmogorov scaling, even though the preshock
density distribution has a shallow spectrum. When the preshock density
distribution has a Kolmogorov spectrum, the turbulent velocity's compressive
component increases.
