linux/fs/crypto/Kconfig

config FS_ENCRYPTION
	tristate "FS Encryption (Per-file encryption)"
	select CRYPTO
	select CRYPTO_AES
	select CRYPTO_CBC
	select CRYPTO_ECB
	select CRYPTO_XTS
	select CRYPTO_CTS
	select CRYPTO_CTR
	select CRYPTO_SHA256
	select KEYS
	help
	  Enable encryption of files and directories.  This
	  feature is similar to ecryptfs, but it is more memory
	  efficient since it avoids caching the encrypted and
	  decrypted pages in the page cache.
fs crypto: move per-file encryption from f2fs tree to fs/crypto This patch adds the renamed functions moved from the f2fs crypto files. 1. definitions for per-file encryption used by ext4 and f2fs. 2. crypto.c for encrypt/decrypt functions a. IO preparation: - fscrypt_get_ctx / fscrypt_release_ctx b. before IOs: - fscrypt_encrypt_page - fscrypt_decrypt_page - fscrypt_zeroout_range c. after IOs: - fscrypt_decrypt_bio_pages - fscrypt_pullback_bio_page - fscrypt_restore_control_page 3. policy.c supporting context management. a. For ioctls: - fscrypt_process_policy - fscrypt_get_policy b. For context permission - fscrypt_has_permitted_context - fscrypt_inherit_context 4. keyinfo.c to handle permissions - fscrypt_get_encryption_info - fscrypt_free_encryption_info 5. fname.c to support filename encryption a. general wrapper functions - fscrypt_fname_disk_to_usr - fscrypt_fname_usr_to_disk - fscrypt_setup_filename - fscrypt_free_filename b. specific filename handling functions - fscrypt_fname_alloc_buffer - fscrypt_fname_free_buffer 6. Makefile and Kconfig Cc: Al Viro <viro@ftp.linux.org.uk> Signed-off-by: Michael Halcrow <mhalcrow@google.com> Signed-off-by: Ildar Muslukhov <ildarm@google.com> Signed-off-by: Uday Savagaonkar <savagaon@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 2015-05-15 23:26:10 +00:00			`config FS_ENCRYPTION`
			`tristate "FS Encryption (Per-file encryption)"`
			`select CRYPTO`
			`select CRYPTO_AES`
			`select CRYPTO_CBC`
			`select CRYPTO_ECB`
			`select CRYPTO_XTS`
			`select CRYPTO_CTS`
			`select CRYPTO_CTR`
fscrypt: add support for AES-128-CBC fscrypt provides facilities to use different encryption algorithms which are selectable by userspace when setting the encryption policy. Currently, only AES-256-XTS for file contents and AES-256-CBC-CTS for file names are implemented. This is a clear case of kernel offers the mechanism and userspace selects a policy. Similar to what dm-crypt and ecryptfs have. This patch adds support for using AES-128-CBC for file contents and AES-128-CBC-CTS for file name encryption. To mitigate watermarking attacks, IVs are generated using the ESSIV algorithm. While AES-CBC is actually slightly less secure than AES-XTS from a security point of view, there is more widespread hardware support. Using AES-CBC gives us the acceptable performance while still providing a moderate level of security for persistent storage. Especially low-powered embedded devices with crypto accelerators such as CAAM or CESA often only support AES-CBC. Since using AES-CBC over AES-XTS is basically thought of a last resort, we use AES-128-CBC over AES-256-CBC since it has less encryption rounds and yields noticeable better performance starting from a file size of just a few kB. Signed-off-by: Daniel Walter <dwalter@sigma-star.at> [david@sigma-star.at: addressed review comments] Signed-off-by: David Gstir <david@sigma-star.at> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> 2017-06-19 07:27:58 +00:00			`select CRYPTO_SHA256`
fs crypto: move per-file encryption from f2fs tree to fs/crypto This patch adds the renamed functions moved from the f2fs crypto files. 1. definitions for per-file encryption used by ext4 and f2fs. 2. crypto.c for encrypt/decrypt functions a. IO preparation: - fscrypt_get_ctx / fscrypt_release_ctx b. before IOs: - fscrypt_encrypt_page - fscrypt_decrypt_page - fscrypt_zeroout_range c. after IOs: - fscrypt_decrypt_bio_pages - fscrypt_pullback_bio_page - fscrypt_restore_control_page 3. policy.c supporting context management. a. For ioctls: - fscrypt_process_policy - fscrypt_get_policy b. For context permission - fscrypt_has_permitted_context - fscrypt_inherit_context 4. keyinfo.c to handle permissions - fscrypt_get_encryption_info - fscrypt_free_encryption_info 5. fname.c to support filename encryption a. general wrapper functions - fscrypt_fname_disk_to_usr - fscrypt_fname_usr_to_disk - fscrypt_setup_filename - fscrypt_free_filename b. specific filename handling functions - fscrypt_fname_alloc_buffer - fscrypt_fname_free_buffer 6. Makefile and Kconfig Cc: Al Viro <viro@ftp.linux.org.uk> Signed-off-by: Michael Halcrow <mhalcrow@google.com> Signed-off-by: Ildar Muslukhov <ildarm@google.com> Signed-off-by: Uday Savagaonkar <savagaon@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 2015-05-15 23:26:10 +00:00			`select KEYS`
			`help`
			`Enable encryption of files and directories. This`
			`feature is similar to ecryptfs, but it is more memory`
			`efficient since it avoids caching the encrypted and`
			`decrypted pages in the page cache.`