Junior GF told me she would expect it to be only on the shell, both inside and outside. Don't treat this information as absolute truth as she was not 100% sure, but she finished Warsaw University of Life Sciences and these things were part of curriculum, so even if she partially guessed that's an educated guess
I could edit, but if someone has seen the answer would miss the edit. First answer was wrong - she checked details. Salmonella can colonize/infect oviducts, so it can be found everywhere, not only on the shell but both in yolk and white.