Uimage Firmware Header: Encrypted Hilink

binwalk -E firmware.bin If the first 1 MB shows high entropy (>0.98) with no known signatures, suspect encryption.

This article explains what it is, how it works, and practical methods to decrypt and analyze it. A normal, unencrypted UImage header (64 bytes) looks like this: encrypted hilink uimage firmware header

# Extract first 64+ bytes of encrypted header (adjust count) dd if=firmware.bin of=enc_header.bin bs=1 count=4096 openssl enc -aes-128-cbc -d -K $KEY -iv $IV -in enc_header.bin -out dec_header.bin Verify magic hexdump -C dec_header.bin | head -1 Should see 56 19 05 27 binwalk -E firmware

If you’ve ever run binwalk on a HiLink firmware update (e.g., from an E3372, B310, or AR series router) and seen only high entropy data with no recognizable UImage magic ( 0x27051956 ), you’ve likely encountered this encrypted header. 0.98) with no known signatures