Re: [PATCH 1/3] crypto: sm4 - create SM4 library based on sm4 generic code

Hi Eric,

On 6/11/21 7:19 AM, Eric Biggers wrote:

On Thu, Jun 10, 2021 at 09:44:57PM +0800, Tianjia Zhang wrote:

quoted

Take the existing small footprint and mostly time invariant C code

It is using an S-box without any prefetching.  That doesn't look very
"time invariant" to me.

Thanks for your suggestion, will do in the next version patch.

quoted

diff --git a/lib/crypto/sm4.c b/lib/crypto/sm4.c
new file mode 100644
index 000000000000..cbdd14a254d0

[..]

quoted

+/**
+ * crypto_sm4_expand_key - Expands the SM4 key as described in GB/T 32907-2016
+ * @ctx:	The location where the computed key will be stored.
+ * @in_key:	The supplied key.
+ * @key_len:	The length of the supplied key.
+ *
+ * Returns 0 on success. The function fails only if an invalid key size (or
+ * pointer) is supplied.
+ */
+int crypto_sm4_expand_key(struct crypto_sm4_ctx *ctx, const u8 *in_key,
+			  unsigned int key_len)

[...]

quoted

+/**
+ * crypto_sm4_do_crypt - Encrypt or decrypt a single SM4 block
+ * @rk:		The rkey_enc for encrypt or rkey_dec for decrypt
+ * @out:	Buffer to store output data
+ * @in: 	Buffer containing the input data
+ */
+void crypto_sm4_do_crypt(const u32 *rk, u8 *out, const u8 *in)

Calling these "sm4_expandkey()" and "sm4_crypt_block()" would be more consistent
with the other lib/crypto/ functions such as the AES ones.  The other
lib/crypto/ functions don't have a "crypto_" prefix, as that is used for
functions related to the traditional crypto API rather than the library API.

Ditto. thanks for pointing it out.

- Eric

Best regards,
Tianjia

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel