This series creates an ESSIV template that produces a skcipher or AEAD transform based on a tuple of the form '<skcipher>,<cipher>,<shash>' (or '<aead>,<cipher>,<shash>' for the AEAD case). It exposes the encapsulated sync or async skcipher/aead by passing through all operations, while using the cipher/shash pair to transform the input IV into an ESSIV output IV. This matches what both users of ESSIV in the kernel do, and so it is proposed as a replacement for those, in patches #2 and #4. This code has been tested using the fscrypt test suggested by Eric (generic/549), as well as the mode-test script suggested by Milan for the dm-crypt case. I also tested the aead case in a virtual machine, but it definitely needs some wider testing from the dm-crypt experts. The consensus appears to be that it would be useful if the crypto API encapsulates the handling of multiple subsequent blocks that are encrypted using a 64-bit LE counter as IV, and makes it the duty of the algo to increment the counter between blocks. However, this is equally suitable for non-ESSIV transforms (or even more so), and so this is left as a future enhancement to be applied on top. Changes since v4: - make the ESSIV template IV size equal the IV size of the encapsulated cipher - defining it as 8 bytes was needlessly restrictive, and also complicated the code for no reason - add a missing kfree() spotted by Smatch - add additional algo length name checks when constructing the essiv() cipher name - reinstate the 'essiv' IV generation implementation in dm-crypt, but make its generation function identical to plain64le (and drop the other methods) - fix a bug in the arm64 CE/NEON code - simplify the arm64 code by reusing more of the existing CBC implementation (patch #6 is new to this series and was added for this reason) Changes since v3: - address various review comments from Eric on patch #1 - use Kconfig's 'imply' instead of 'select' to permit CRYPTO_ESSIV to be enabled as a module or disabled entirely even if fscrypt is compiled in (#2) - fix an issue in the AEAD encrypt path caused by the IV being clobbered by the inner skcipher before the hmac was being calculated Changes since v2: - fixed a couple of bugs that snuck in after I'd done the bulk of my testing - some cosmetic tweaks to the ESSIV template skcipher setkey function to align it with the aead one - add a test case for essiv(cbc(aes),aes,sha256) - add an accelerated implementation for arm64 that combines the IV derivation and the actual en/decryption in a single asm routine Scroll down for tcrypt speed test result comparing the essiv template with the asm implementation. Bare cbc(aes) tests included for reference as well. Taken on a 2GHz Cortex-A57 (AMD Seattle) Code can be found here https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/log/?h=essiv-v5 Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: Eric Biggers <ebiggers@xxxxxxxxxx> Cc: dm-devel@xxxxxxxxxx Cc: linux-fscrypt@xxxxxxxxxxxxxxx Cc: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx> Cc: Milan Broz <gmazyland@xxxxxxxxx> Ard Biesheuvel (7): crypto: essiv - create wrapper template for ESSIV generation fs: crypto: invoke crypto API for ESSIV handling md: dm-crypt: infer ESSIV block cipher from cipher string directly md: dm-crypt: switch to ESSIV crypto API template crypto: essiv - add test vector for essiv(cbc(aes),aes,sha256) crypto: arm64/aes-cts-cbc - factor out CBC en/decryption of a walk crypto: arm64/aes - implement accelerated ESSIV/CBC mode arch/arm64/crypto/aes-glue.c | 205 +++++-- arch/arm64/crypto/aes-modes.S | 29 +- crypto/Kconfig | 4 + crypto/Makefile | 1 + crypto/essiv.c | 636 ++++++++++++++++++++ crypto/tcrypt.c | 9 + crypto/testmgr.c | 6 + crypto/testmgr.h | 213 +++++++ drivers/md/Kconfig | 1 + drivers/md/dm-crypt.c | 229 ++----- fs/crypto/Kconfig | 1 + fs/crypto/crypto.c | 5 - fs/crypto/fscrypt_private.h | 9 - fs/crypto/keyinfo.c | 88 +-- 14 files changed, 1111 insertions(+), 325 deletions(-) create mode 100644 crypto/essiv.c -- 2.20.1
