diff options
| -rw-r--r-- | Documentation/filesystems/fscrypt.rst | 10 | ||||
| -rw-r--r-- | fs/crypto/fscrypt_private.h | 4 | ||||
| -rw-r--r-- | fs/crypto/keyinfo.c | 2 | ||||
| -rw-r--r-- | include/uapi/linux/fs.h | 2 |
4 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index cfbc18f0d9c9..48b424de85bb 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -191,11 +191,21 @@ 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 +- Speck128/256-XTS for contents and Speck128/256-CTS-CBC for filenames It is strongly recommended to use AES-256-XTS for contents encryption. AES-128-CBC was added only for low-powered embedded devices with crypto accelerators such as CAAM or CESA that do not support XTS. +Similarly, Speck128/256 support was only added for older or low-end +CPUs which cannot do AES fast enough -- especially ARM CPUs which have +NEON instructions but not the Cryptography Extensions -- and for which +it would not otherwise be feasible to use encryption at all. It is +not recommended to use Speck on CPUs that have AES instructions. +Speck support is only available if it has been enabled in the crypto +API via CONFIG_CRYPTO_SPECK. Also, on ARM platforms, to get +acceptable performance CONFIG_CRYPTO_SPECK_NEON must be enabled. + 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 diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 09d6c72635b6..37562394c5de 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -83,6 +83,10 @@ static inline bool fscrypt_valid_enc_modes(u32 contents_mode, filenames_mode == FS_ENCRYPTION_MODE_AES_256_CTS) return true; + if (contents_mode == FS_ENCRYPTION_MODE_SPECK128_256_XTS && + filenames_mode == FS_ENCRYPTION_MODE_SPECK128_256_CTS) + return true; + return false; } diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c index c4d1388fc9b4..41f6025d5d7a 100644 --- a/fs/crypto/keyinfo.c +++ b/fs/crypto/keyinfo.c @@ -156,6 +156,8 @@ static const struct { [FS_ENCRYPTION_MODE_AES_256_CTS] = { "cts(cbc(aes))", 32 }, [FS_ENCRYPTION_MODE_AES_128_CBC] = { "cbc(aes)", 16 }, [FS_ENCRYPTION_MODE_AES_128_CTS] = { "cts(cbc(aes))", 16 }, + [FS_ENCRYPTION_MODE_SPECK128_256_XTS] = { "xts(speck128)", 64 }, + [FS_ENCRYPTION_MODE_SPECK128_256_CTS] = { "cts(cbc(speck128))", 32 }, }; static int determine_cipher_type(struct fscrypt_info *ci, struct inode *inode, diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index d2a8313fabd7..0b6e07ee63a6 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -275,6 +275,8 @@ struct fsxattr { #define FS_ENCRYPTION_MODE_AES_256_CTS 4 #define FS_ENCRYPTION_MODE_AES_128_CBC 5 #define FS_ENCRYPTION_MODE_AES_128_CTS 6 +#define FS_ENCRYPTION_MODE_SPECK128_256_XTS 7 +#define FS_ENCRYPTION_MODE_SPECK128_256_CTS 8 struct fscrypt_policy { __u8 version; |