Device-mapper "integrity" target provides transparent cryptographic integrity protection of underlying read-write block device using hash-based message authentication codes (HMACs), which can be stored on the same or different block device. Target uses kernel keyring to obtain a secret key for using in cryptographic operations. It uses encrypted key type. Kernel never exposes those keys in plain form to user space. Encrypted keys are encrypted using master key, which can be either user or trusted type. User key type allows to supply a key from the user space and trusted key uses TPM. Secret key is usually device specific and binds integrity data to the device. Data blocks and corresponding HMACs cannot be copied over from other systems. The key advantage over dm-verity is that the target supports read-write and requires less hash calculation operations, but it cannot be used to build a a file system image to be used on multiple devices unless secret key is the same across all device. The main purpose is to provide read-write capable local block data integrity protection. Changes in v2: - added block size parameter - added hmac algo parameter - fixed table output - added sync mode flag to handle reboot notifications - added discards handling - use DM functions for printing kernel messages - Dmitry Dmitry Kasatkin (1): dm-integrity: integrity protection device-mapper target Documentation/device-mapper/dm-integrity.txt | 137 ++++ drivers/md/Kconfig | 13 + drivers/md/Makefile | 1 + drivers/md/dm-integrity.c | 1050 ++++++++++++++++++++++++++ 4 files changed, 1201 insertions(+) create mode 100644 Documentation/device-mapper/dm-integrity.txt create mode 100644 drivers/md/dm-integrity.c -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html