[This patchset is based on v5.17-rc6. It can also be retrieved from tag "wrapped-keys-v5" of https://git.kernel.org/pub/scm/fs/fscrypt/fscrypt.git] This patchset adds block and fscrypt support for hardware-wrapped keys when the inline encryption hardware supports them. Hardware-wrapped keys are inline encryption keys that are wrapped (encrypted) by a key internal to the hardware. The wrapping key is an ephemeral per-boot key, except at initial unlocking time. Hardware-wrapped keys can only be unwrapped (decrypted) by the hardware, e.g. when a key is programmed into a keyslot. They are never visible to software in raw form, except optionally during key generation. The hardware supports importing keys as well as generating keys itself. This feature protects encryption keys from read-only compromises of kernel memory, such as that which can occur during a cold boot attack. It does this without limiting the number of keys that can be used, as would be the case with solutions that didn't use key wrapping. Hardware supporting this feature is present on recent Qualcomm SoCs (SM8350 and later) as well as on the Google Tensor SoC. This patchset is organized as follows: - Patch 1 adds the block support and documentation, excluding the ioctls needed to get a key ready to be used in the first place. - Patch 2 adds new block device ioctls for importing, generating, and preparing hardware-wrapped keys. - Patch 3 adds the fscrypt support and documentation. For full details, see the individual patches, especially the detailed documentation they add to Documentation/block/inline-encryption.rst and Documentation/filesystems/fscrypt.rst. This feature also requires UFS driver changes. For Qualcomm SoCs, these are being worked on at https://lore.kernel.org/linux-scsi/20211206225725.77512-1-quic_gaurkash@xxxxxxxxxxx/T/#u. I've verified that this feature works end-to-end on the SM8350 HDK with the upstream kernel with these two patchsets applied. (One caveat is that a custom TrustZone image needs to be flashed to the board too; I understand that Qualcomm is working on addressing that.) I've also written xfstests which verify that this feature encrypts files correctly. These tests can currently be found at https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/xfstests-dev.git/log/?h=wip-wrapped-keys. I'll be sending these tests in a separate patchset. Changed v4 => v5: - Dropped the RFC tag, now that these patches are actually testable. - Split the BLKCRYPTOCREATEKEY ioctl into BLKCRYPTOIMPORTKEY and BLKCRYPTOGENERATEKEY. (I'm thinking that these operations are distinct enough that two separate ioctls would be best.) - Added some warning messages in fscrypt_derive_sw_secret(). - Rebased onto v5.17-rc6. Changed v3 => v4: - Rebased onto v5.16-rc1 and dropped a few bits that were upstreamed. - Updated cover letter to link to Gaurav's UFS driver patchset. Changed v2 => v3: - Dropped some fscrypt cleanups that were applied. - Rebased on top of the latest linux-block and fscrypt branches. - Minor cleanups. Changed v1 => v2: - Added new ioctls for creating and preparing hardware-wrapped keys. - Rebased onto my patchset which renames blk_keyslot_manager to blk_crypto_profile. Eric Biggers (3): block: add basic hardware-wrapped key support block: add ioctls to create and prepare hardware-wrapped keys fscrypt: add support for hardware-wrapped keys Documentation/block/inline-encryption.rst | 241 +++++++++++++++++++++- Documentation/filesystems/fscrypt.rst | 154 ++++++++++++-- block/blk-crypto-fallback.c | 5 +- block/blk-crypto-internal.h | 10 + block/blk-crypto-profile.c | 97 +++++++++ block/blk-crypto.c | 190 ++++++++++++++++- block/ioctl.c | 5 + drivers/md/dm-table.c | 1 + drivers/mmc/host/cqhci-crypto.c | 2 + drivers/scsi/ufs/ufshcd-crypto.c | 1 + fs/crypto/fscrypt_private.h | 72 ++++++- fs/crypto/hkdf.c | 4 +- fs/crypto/inline_crypt.c | 75 ++++++- fs/crypto/keyring.c | 119 ++++++++--- fs/crypto/keysetup.c | 71 ++++++- fs/crypto/keysetup_v1.c | 5 +- fs/crypto/policy.c | 11 +- include/linux/blk-crypto-profile.h | 80 +++++++ include/linux/blk-crypto.h | 70 ++++++- include/uapi/linux/fs.h | 26 +++ include/uapi/linux/fscrypt.h | 7 +- 21 files changed, 1153 insertions(+), 93 deletions(-) base-commit: 7e57714cd0ad2d5bb90e50b5096a0e671dec1ef3 -- 2.35.1
