[PATCH v4 1/2] blk-crypto: Add support for SM4-XTS blk crypto mode

[Tianjia Zhang]

SM4 is a symmetric cipher algorithm widely used in China. The SM4-XTS
variant is used to encrypt length-preserving data. This is the
mandatory algorithm in some special scenarios.

Enable the algorithm in block inline encryption, this is needed for the
inlinecrypt mount option to be supported via blk-crypto-fallback, as it
is for the other fscrypt modes.

Signed-off-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx>
---
 block/blk-crypto.c         | 6 ++++++
 include/linux/blk-crypto.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/block/blk-crypto.c b/block/blk-crypto.c
index a496aaef85ba..e44709fc6a08 100644
--- a/block/blk-crypto.c
+++ b/block/blk-crypto.c
@@ -36,6 +36,12 @@ const struct blk_crypto_mode blk_crypto_modes[] = {
 		.keysize = 32,
 		.ivsize = 32,
 	},
+	[BLK_ENCRYPTION_MODE_SM4_XTS] = {
+		.name = "SM4-XTS",
+		.cipher_str = "xts(sm4)",
+		.keysize = 32,
+		.ivsize = 16,
+	},
 };
 
 /*
diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h
index 69b24fe92cbf..26b1b71c3091 100644
--- a/include/linux/blk-crypto.h
+++ b/include/linux/blk-crypto.h
@@ -13,6 +13,7 @@ enum blk_crypto_mode_num {
 	BLK_ENCRYPTION_MODE_AES_256_XTS,
 	BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV,
 	BLK_ENCRYPTION_MODE_ADIANTUM,
+	BLK_ENCRYPTION_MODE_SM4_XTS,
 	BLK_ENCRYPTION_MODE_MAX,
 };
 
-- 
2.24.3 (Apple Git-128)