verify_buffer: check that the value of cert->Hdr.dwLength is reasonable
verify_buffer: check that the value of cert->Hdr.dwLength is reasonable

Signed-off-by: Peter Jones <2e0a021e603479ff81838c00c3b770daca4e0214@redhat.com>

rhinstaller/shim,rhinstaller/shim,rhinstaller/shim