CODEWITHSUNDEEP
kernelyoctorootfsyocto-layerubifs
cherry411
cherry411

Reputation: 23

Can dm-verity will support authentication of Ubifs root file system in Linux

I want to authenticate my root file system which is in Ubifs file type mounted on NAND flash device.

Will dm-verity will support ubifs file system ?

In dm-verity-img.bb class file i have seen only below file systems mentioned.

DM_VERITY_IMAGE = "core-image-full-cmdline" # or other image
DM_VERITY_IMAGE_TYPE = "ext4" # or ext2, ext3 & btrfs
IMAGE_CLASSES += "dm-verity-img"

Upvotes: 0

Views: 351

Answers (1)

Weana
Weana

Reputation: 133

the mechanism for signing and verifying your software, using dm-verity, is called a "Merkel Tree". Within that approach, you are using blocks of data to create a hash tree of your data to protect. This tree in turn can be used fast at runtime to make integrity checks within the device mapper "on-the-fly". With on-the-fly I mean directly, when the data is accessed from user space in a way, where the performance of the system is not impacted.

That being said, dm-verity is working in connection with block-oriented filesystems, like ext4, squashfs, etc. UBIFS in turn is kind of a "special" filesystem, explicitly not characterized as block device. You can check e.g. https://docs.kernel.org/filesystems/ubifs.html for reference.

Hence my understanding - also bolstered by an actual implementation in an embedded system, using both squashfs and UBIFS - is that you cannot use dm-verity for UBIFS.

Hope that helps!

Upvotes: 1

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