Hashtree Patcher

Hashtree Patcher is an Android command-line tool that patches vendor_dlkm.img and vbmeta.img for booting without disabling verity. It also has tools for checking if verity and verification are disabled in the top-level vbmeta and if a given partition has an avb fs option.

Usage

httools patch <partition-name> <partition.img> <vbmeta.img>

A hashtree footer is appended to the partition image, and the specified hashtree descriptor in the vbmeta image is patched with the relevant values. Both images are patched in place.

FEC

If the fec binary is present in the working directory, it will be used to generate FEC data. Prebuilt binaries are available here.

httools avb <partition-name>

Checks if the partition has an avb fs option, the value of which is printed, if so.

httools disable-flags

Checks if verity or verification are disabled in the top-level vbmeta.

httools mount <partition-name>

Mounts the partition, with a hashtree if verity and verification are enabled.

httools umount <partition-name>

Unmounts the partition and tears down its hashtree if verity and verification are enabled.

httools --version

Prints the current version and exits.