[PATCH v4 4/4] fscrypt: Add LEA-256-XTS, LEA-256-CTS support

[Dongsoo Lee]

It uses LEA-256-XTS for file encryption and LEA-256-CTS-CBC for
filename encryption. Includes constant changes as the number of
supported ciphers increases.

Signed-off-by: Dongsoo Lee <letrhee@xxxxxxxxx>
---
 fs/crypto/fscrypt_private.h        |  2 +-
 fs/crypto/keysetup.c               | 15 +++++++++++++++
 fs/crypto/policy.c                 |  4 ++++
 include/uapi/linux/fscrypt.h       |  4 +++-
 tools/include/uapi/linux/fscrypt.h |  4 +++-
 5 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 2d63da48635a..df8075478f11 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -31,7 +31,7 @@
 #define FSCRYPT_CONTEXT_V2	2
 
 /* Keep this in sync with include/uapi/linux/fscrypt.h */
-#define FSCRYPT_MODE_MAX	FSCRYPT_MODE_AES_256_HCTR2
+#define FSCRYPT_MODE_MAX	FSCRYPT_MODE_LEA_256_CTS
 
 struct fscrypt_context_v1 {
 	u8 version; /* FSCRYPT_CONTEXT_V1 */
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index 361f41ef46c7..fa82579e56eb 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -74,6 +74,21 @@ struct fscrypt_mode fscrypt_modes[] = {
 		.security_strength = 32,
 		.ivsize = 32,
 	},
+	[FSCRYPT_MODE_LEA_256_XTS] = {
+		.friendly_name = "LEA-256-XTS",
+		.cipher_str = "xts(lea)",
+		.keysize = 64,
+		.security_strength = 32,
+		.ivsize = 16,
+		.blk_crypto_mode = BLK_ENCRYPTION_MODE_LEA_256_XTS,
+	},
+	[FSCRYPT_MODE_LEA_256_CTS] = {
+		.friendly_name = "LEA-256-CTS-CBC",
+		.cipher_str = "cts(cbc(lea))",
+		.keysize = 32,
+		.security_strength = 32,
+		.ivsize = 16,
+	},
 };
 
 static DEFINE_MUTEX(fscrypt_mode_key_setup_mutex);
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index f4456ecb3f87..9d1e80c43c6d 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -94,6 +94,10 @@ static bool fscrypt_valid_enc_modes_v2(u32 contents_mode, u32 filenames_mode)
 	    filenames_mode == FSCRYPT_MODE_SM4_CTS)
 		return true;
 
+	if (contents_mode == FSCRYPT_MODE_LEA_256_XTS &&
+	    filenames_mode == FSCRYPT_MODE_LEA_256_CTS)
+		return true;
+
 	return fscrypt_valid_enc_modes_v1(contents_mode, filenames_mode);
 }
 
diff --git a/include/uapi/linux/fscrypt.h b/include/uapi/linux/fscrypt.h
index fd1fb0d5389d..df3c8af98210 100644
--- a/include/uapi/linux/fscrypt.h
+++ b/include/uapi/linux/fscrypt.h
@@ -30,7 +30,9 @@
 #define FSCRYPT_MODE_SM4_CTS			8
 #define FSCRYPT_MODE_ADIANTUM			9
 #define FSCRYPT_MODE_AES_256_HCTR2		10
-/* If adding a mode number > 10, update FSCRYPT_MODE_MAX in fscrypt_private.h */
+#define FSCRYPT_MODE_LEA_256_XTS		11
+#define FSCRYPT_MODE_LEA_256_CTS		12
+/* If adding a mode number > 12, update FSCRYPT_MODE_MAX in fscrypt_private.h */
 
 /*
  * Legacy policy version; ad-hoc KDF and no key verification.
diff --git a/tools/include/uapi/linux/fscrypt.h b/tools/include/uapi/linux/fscrypt.h
index fd1fb0d5389d..df3c8af98210 100644
--- a/tools/include/uapi/linux/fscrypt.h
+++ b/tools/include/uapi/linux/fscrypt.h
@@ -30,7 +30,9 @@
 #define FSCRYPT_MODE_SM4_CTS			8
 #define FSCRYPT_MODE_ADIANTUM			9
 #define FSCRYPT_MODE_AES_256_HCTR2		10
-/* If adding a mode number > 10, update FSCRYPT_MODE_MAX in fscrypt_private.h */
+#define FSCRYPT_MODE_LEA_256_XTS		11
+#define FSCRYPT_MODE_LEA_256_CTS		12
+/* If adding a mode number > 12, update FSCRYPT_MODE_MAX in fscrypt_private.h */
 
 /*
  * Legacy policy version; ad-hoc KDF and no key verification.
-- 
2.34.1