| Message ID | 20221125121630.87793-3-tianjia.zhang@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add SM4 XTS symmetric algorithm for blk-crypto and fscrypt | expand |
On Fri, Nov 25, 2022 at 08:16:30PM +0800, Tianjia Zhang wrote: > diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c > index 46757c3052ef..8e69bc0c35cd 100644 > --- a/fs/crypto/policy.c > +++ b/fs/crypto/policy.c > @@ -71,6 +71,10 @@ static bool fscrypt_valid_enc_modes_v1(u32 contents_mode, u32 filenames_mode) > filenames_mode == FSCRYPT_MODE_AES_128_CTS) > return true; > > + if (contents_mode == FSCRYPT_MODE_SM4_XTS && > + filenames_mode == FSCRYPT_MODE_SM4_CTS) > + return true; > + > if (contents_mode == FSCRYPT_MODE_ADIANTUM && > filenames_mode == FSCRYPT_MODE_ADIANTUM) > return true; Sorry, one more thing I didn't notice before. Since this is a new feature, please only allow it in fscrypt_valid_enc_modes_v2(), not in fscrypt_valid_enc_modes_v1(). That's what we did for AES-256-XTS + AES-256-HCTR2 recently. There should be no need to add new features to v1 encryption policies, which have been deprecated for several years. - Eric
Hi Eric, On 11/26/22 2:24 AM, Eric Biggers wrote: > On Fri, Nov 25, 2022 at 08:16:30PM +0800, Tianjia Zhang wrote: >> diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c >> index 46757c3052ef..8e69bc0c35cd 100644 >> --- a/fs/crypto/policy.c >> +++ b/fs/crypto/policy.c >> @@ -71,6 +71,10 @@ static bool fscrypt_valid_enc_modes_v1(u32 contents_mode, u32 filenames_mode) >> filenames_mode == FSCRYPT_MODE_AES_128_CTS) >> return true; >> >> + if (contents_mode == FSCRYPT_MODE_SM4_XTS && >> + filenames_mode == FSCRYPT_MODE_SM4_CTS) >> + return true; >> + >> if (contents_mode == FSCRYPT_MODE_ADIANTUM && >> filenames_mode == FSCRYPT_MODE_ADIANTUM) >> return true; > > Sorry, one more thing I didn't notice before. Since this is a new feature, > please only allow it in fscrypt_valid_enc_modes_v2(), not in > fscrypt_valid_enc_modes_v1(). That's what we did for AES-256-XTS + > AES-256-HCTR2 recently. There should be no need to add new features to > v1 encryption policies, which have been deprecated for several years. > > - Eric Thanks for reminder, it makes sense to only support the new algorithm in v2 policy, which I will do this. BR, Tianjia
On 11/25/22 19:16, Tianjia Zhang wrote: > SM4 is a symmetric algorithm widely used in China, and is even mandatory > in many scenarios. We need to provide these users with the ability to > encrypt files or disks using SM4-XTS, and many other algorithms that use > SM2/3/4 algorithms or their combined algorithm scenarios, these features > are demanded by many users, this patch enables to use SM4-XTS mode to > encrypt file content, and use SM4-CBC-CTS to encrypt filename. > Similar reply as [1]. That is, better say: ``` Add support for XTS and CTS mode variant of SM4 algorithm, in similar fashion to SM2 and SM3. The former is used to encrypt file contents, while the latter (SM4-CBC-CTS) is used to encrypt filenames. ``` Thanks. [1]: https://lore.kernel.org/linux-doc/42624542-6ccb-26a5-db98-d7944972246e@gmail.com/
Hi Bagas, On 11/28/22 9:33 PM, Bagas Sanjaya wrote: > On 11/25/22 19:16, Tianjia Zhang wrote: >> SM4 is a symmetric algorithm widely used in China, and is even mandatory >> in many scenarios. We need to provide these users with the ability to >> encrypt files or disks using SM4-XTS, and many other algorithms that use >> SM2/3/4 algorithms or their combined algorithm scenarios, these features >> are demanded by many users, this patch enables to use SM4-XTS mode to >> encrypt file content, and use SM4-CBC-CTS to encrypt filename. >> > > Similar reply as [1]. That is, better say: > > ``` > Add support for XTS and CTS mode variant of SM4 algorithm, in similar > fashion to SM2 and SM3. The former is used to encrypt file contents, while > the latter (SM4-CBC-CTS) is used to encrypt filenames. > ``` > > Thanks. > > [1]: https://lore.kernel.org/linux-doc/42624542-6ccb-26a5-db98-d7944972246e@gmail.com/ > Thanks for your reply, it is very valuable for me, I will update it in the next patch. Cheers, Tianjia
diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 5ba5817c17c2..af27e7b2c74f 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -336,6 +336,7 @@ 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 +- SM4-XTS for contents and SM4-CTS-CBC for filenames - Adiantum for both contents and filenames - AES-256-XTS for contents and AES-256-HCTR2 for filenames (v2 policies only) diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index f7407071a952..24e55c95abc3 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -44,6 +44,21 @@ struct fscrypt_mode fscrypt_modes[] = { .security_strength = 16, .ivsize = 16, }, + [FSCRYPT_MODE_SM4_XTS] = { + .friendly_name = "SM4-XTS", + .cipher_str = "xts(sm4)", + .keysize = 32, + .security_strength = 16, + .ivsize = 16, + .blk_crypto_mode = BLK_ENCRYPTION_MODE_SM4_XTS, + }, + [FSCRYPT_MODE_SM4_CTS] = { + .friendly_name = "SM4-CTS", + .cipher_str = "cts(cbc(sm4))", + .keysize = 16, + .security_strength = 16, + .ivsize = 16, + }, [FSCRYPT_MODE_ADIANTUM] = { .friendly_name = "Adiantum", .cipher_str = "adiantum(xchacha12,aes)", diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index 46757c3052ef..8e69bc0c35cd 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -71,6 +71,10 @@ static bool fscrypt_valid_enc_modes_v1(u32 contents_mode, u32 filenames_mode) filenames_mode == FSCRYPT_MODE_AES_128_CTS) return true; + if (contents_mode == FSCRYPT_MODE_SM4_XTS && + filenames_mode == FSCRYPT_MODE_SM4_CTS) + return true; + if (contents_mode == FSCRYPT_MODE_ADIANTUM && filenames_mode == FSCRYPT_MODE_ADIANTUM) return true; diff --git a/include/uapi/linux/fscrypt.h b/include/uapi/linux/fscrypt.h index a756b29afcc2..47dbd1994bfe 100644 --- a/include/uapi/linux/fscrypt.h +++ b/include/uapi/linux/fscrypt.h @@ -26,6 +26,8 @@ #define FSCRYPT_MODE_AES_256_CTS 4 #define FSCRYPT_MODE_AES_128_CBC 5 #define FSCRYPT_MODE_AES_128_CTS 6 +#define FSCRYPT_MODE_SM4_XTS 7 +#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 */
SM4 is a symmetric algorithm widely used in China, and is even mandatory in many scenarios. We need to provide these users with the ability to encrypt files or disks using SM4-XTS, and many other algorithms that use SM2/3/4 algorithms or their combined algorithm scenarios, these features are demanded by many users, this patch enables to use SM4-XTS mode to encrypt file content, and use SM4-CBC-CTS to encrypt filename. Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com> --- Documentation/filesystems/fscrypt.rst | 1 + fs/crypto/keysetup.c | 15 +++++++++++++++ fs/crypto/policy.c | 4 ++++ include/uapi/linux/fscrypt.h | 2 ++ 4 files changed, 22 insertions(+)