-int crypto_sm4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
- unsigned int key_len);
-int crypto_sm4_expand_key(struct crypto_sm4_ctx *ctx, const u8 *in_key,
+/**
+ * sm4_expandkey - 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 sm4_expandkey(struct sm4_ctx *ctx, const u8 *in_key,