Merge tag 'v5.20-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto updates from Herbert Xu:
"API:

   - Make proc files report fips module name and version

  Algorithms:

   - Move generic SHA1 code into lib/crypto

   - Implement Chinese Remainder Theorem for RSA

   - Remove blake2s

   - Add XCTR with x86/arm64 acceleration

   - Add POLYVAL with x86/arm64 acceleration

   - Add HCTR2

   - Add ARIA

  Drivers:

   - Add support for new CCP/PSP device ID in ccp"

* tag 'v5.20-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (89 commits)
  crypto: tcrypt - Remove the static variable initialisations to NULL
  crypto: arm64/poly1305 - fix a read out-of-bound
  crypto: hisilicon/zip - Use the bitmap API to allocate bitmaps
  crypto: hisilicon/sec - fix auth key size error
  crypto: ccree - Remove a useless dma_supported() call
  crypto: ccp - Add support for new CCP/PSP device ID
  crypto: inside-secure - Add missing MODULE_DEVICE_TABLE for of
  crypto: hisilicon/hpre - don't use GFP_KERNEL to alloc mem during softirq
  crypto: testmgr - some more fixes to RSA test vectors
  cyrpto: powerpc/aes - delete the rebundant word "block" in comments
  hwrng: via - Fix comment typo
  crypto: twofish - Fix comment typo
  crypto: rmd160 - fix Kconfig "its" grammar
  crypto: keembay-ocs-ecc - Drop if with an always false condition
  Documentation: qat: rewrite description
  Documentation: qat: Use code block for qat sysfs example
  crypto: lib - add module license to libsha1
  crypto: lib - make the sha1 library optional
  crypto: lib - move lib/sha1.c into lib/crypto/
  crypto: fips - make proc files report fips module name and version
  ...

1 files changed, 17 insertions, 5 deletions

diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst
index 2e9aaa295125..5ba5817c17c2 100644
--- a/Documentation/filesystems/fscrypt.rst
+++ b/Documentation/filesystems/fscrypt.rst
@@ -337,6 +337,7 @@ Currently, the following pairs of encryption modes are supported:
 - AES-256-XTS for contents and AES-256-CTS-CBC for filenames
 - AES-128-CBC for contents and AES-128-CTS-CBC for filenames
 - Adiantum for both contents and filenames
+- AES-256-XTS for contents and AES-256-HCTR2 for filenames (v2 policies only)
 
 If unsure, you should use the (AES-256-XTS, AES-256-CTS-CBC) pair.
 
@@ -357,6 +358,17 @@ To use Adiantum, CONFIG_CRYPTO_ADIANTUM must be enabled.  Also, fast
 implementations of ChaCha and NHPoly1305 should be enabled, e.g.
 CONFIG_CRYPTO_CHACHA20_NEON and CONFIG_CRYPTO_NHPOLY1305_NEON for ARM.
 
+AES-256-HCTR2 is another true wide-block encryption mode that is intended for
+use on CPUs with dedicated crypto instructions.  AES-256-HCTR2 has the property
+that a bitflip in the plaintext changes the entire ciphertext.  This property
+makes it desirable for filename encryption since initialization vectors are
+reused within a directory.  For more details on AES-256-HCTR2, see the paper
+"Length-preserving encryption with HCTR2"
+(https://eprint.iacr.org/2021/1441.pdf).  To use AES-256-HCTR2,
+CONFIG_CRYPTO_HCTR2 must be enabled.  Also, fast implementations of XCTR and
+POLYVAL should be enabled, e.g. CRYPTO_POLYVAL_ARM64_CE and
+CRYPTO_AES_ARM64_CE_BLK for ARM64.
+
 New encryption modes can be added relatively easily, without changes
 to individual filesystems.  However, authenticated encryption (AE)
 modes are not currently supported because of the difficulty of dealing
@@ -404,11 +416,11 @@ alternatively has the file's nonce (for `DIRECT_KEY policies`_) or
 inode number (for `IV_INO_LBLK_64 policies`_) included in the IVs.
 Thus, IV reuse is limited to within a single directory.
 
-With CTS-CBC, the IV reuse means that when the plaintext filenames
-share a common prefix at least as long as the cipher block size (16
-bytes for AES), the corresponding encrypted filenames will also share
-a common prefix.  This is undesirable.  Adiantum does not have this
-weakness, as it is a wide-block encryption mode.
+With CTS-CBC, the IV reuse means that when the plaintext filenames share a
+common prefix at least as long as the cipher block size (16 bytes for AES), the
+corresponding encrypted filenames will also share a common prefix.  This is
+undesirable.  Adiantum and HCTR2 do not have this weakness, as they are
+wide-block encryption modes.
 
 All supported filenames encryption modes accept any plaintext length
 >= 16 bytes; cipher block alignment is not required.  However,