Re: [PATCH v3 1/2] blk-crypto: Add support for SM4-XTS blk crypto mode

[Jens Axboe <axboe@kernel.dk>]

On 11/25/22 11:35 AM, Eric Biggers wrote:
> On Fri, Nov 25, 2022 at 08:16:29PM +0800, Tianjia Zhang wrote:
>> SM4 is a symmetric algorithm widely used in China, and SM4-XTS is also
>> used to encrypt length-preserving data, these algoritms are mandatory
>> in many scenarios. This patch enables the use of SM4-XTS algorithm in
>> block inline encryption, and provides support for fscrypt.
>>
>> Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
>> ---
>>  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,
> 
> The commit message should mention that this is needed for the inlinecrypt mount
> option to be supported via blk-crypto-fallback, as it is for the other fscrypt
> modes.  (Since there's no inline encryption hardware that supports SM4-XTS.)
> 
> Anyway, if SM4-XTS support is really being added to fscrypt, then this patch
> looks fine.  Jens, are you okay with me taking it through the fscrypt tree?

Yes, go ahead.

-- 
Jens Axboe