-void lfsr_rollback_bit(struct Crypto1State* s, uint32_t in, int fb);
-void lfsr_rollback_byte(struct Crypto1State* s, uint32_t in, int fb);
-void lfsr_rollback_word(struct Crypto1State* s, uint32_t in, int fb);
+
+uint8_t lfsr_rollback_bit(struct Crypto1State* s, uint32_t in, int fb);
+uint8_t lfsr_rollback_byte(struct Crypto1State* s, uint32_t in, int fb);
+uint32_t lfsr_rollback_word(struct Crypto1State* s, uint32_t in, int fb);