
Samsung Galaxy J1
Every official firmware build for SM-J100H, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/J100HXXU0AQK1
Box codes of SM-J100H for different colors and markets. Firmware is chosen by the model code SM-J100H and your region (CSC), not by the SKU.

SM-J100VPP

SM-J106M

SM-J105Y

SM-J200GU

SM-J110M
You can find the firmware on the model: SM-J100H page.
Yes, all firmware files for SM-J100H are 100% official, original, and obtained directly from Samsung servers.
To flash SM-J100H, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-J100H.