crypto: sm3 - Replace with wrapper around library

Reimplement the "sm3" crypto_shash on top of the SM3 library, closely
mirroring the other hash algorithms (e.g. SHA-*).

The result, after later commits migrate the architecture-optimized SM3
code into the library as well, is that crypto/sm3.c will be the single
point of integration between crypto_shash and the actual SM3
implementations, simplifying the code.

Note: to see the diff from crypto/sm3_generic.c to crypto/sm3.c, view
this commit with 'git show -M10'.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260321040935.410034-7-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

Author: Eric Biggers

crypto/Makefile

@@ -83,7 +83,7 @@ obj-$(CONFIG_CRYPTO_SHA1) += sha1.o
 obj-$(CONFIG_CRYPTO_SHA256) += sha256.o
 obj-$(CONFIG_CRYPTO_SHA512) += sha512.o
 obj-$(CONFIG_CRYPTO_SHA3) += sha3.o
-obj-$(CONFIG_CRYPTO_SM3) += sm3_generic.o
+obj-$(CONFIG_CRYPTO_SM3) += sm3.o
 obj-$(CONFIG_CRYPTO_STREEBOG) += streebog_generic.o
 obj-$(CONFIG_CRYPTO_WP512) += wp512.o
 CFLAGS_wp512.o := $(call cc-option,-fno-schedule-insns)  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79149

crypto/sm3.c

@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SM3 secure hash, as specified by OSCCA GM/T 0004-2012 SM3 and
+ * described at https://tools.ietf.org/html/draft-shen-sm3-hash-01
+ *
+ * Copyright (C) 2017 ARM Limited or its affiliates.
+ * Written by Gilad Ben-Yossef <gilad@benyossef.com>
+ * Copyright (C) 2021 Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
+ * Copyright 2026 Google LLC
+ */
+
+#include <crypto/internal/hash.h>
+#include <crypto/sm3.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#define SM3_CTX(desc) ((struct sm3_ctx *)shash_desc_ctx(desc))
+
+static int crypto_sm3_init(struct shash_desc *desc)
+{
+	sm3_init(SM3_CTX(desc));
+	return 0;
+}
+
+static int crypto_sm3_update(struct shash_desc *desc,
+			     const u8 *data, unsigned int len)
+{
+	sm3_update(SM3_CTX(desc), data, len);
+	return 0;
+}
+
+static int crypto_sm3_final(struct shash_desc *desc, u8 *out)
+{
+	sm3_final(SM3_CTX(desc), out);
+	return 0;
+}
+
+static int crypto_sm3_digest(struct shash_desc *desc,
+			     const u8 *data, unsigned int len, u8 *out)
+{
+	sm3(data, len, out);
+	return 0;
+}
+
+static int crypto_sm3_export_core(struct shash_desc *desc, void *out)
+{
+	memcpy(out, SM3_CTX(desc), sizeof(struct sm3_ctx));
+	return 0;
+}
+
+static int crypto_sm3_import_core(struct shash_desc *desc, const void *in)
+{
+	memcpy(SM3_CTX(desc), in, sizeof(struct sm3_ctx));
+	return 0;
+}
+
+static struct shash_alg sm3_alg = {
+	.base.cra_name		= "sm3",
+	.base.cra_driver_name	= "sm3-lib",
+	.base.cra_priority	= 300,
+	.base.cra_blocksize	= SM3_BLOCK_SIZE,
+	.base.cra_module	= THIS_MODULE,
+	.digestsize		= SM3_DIGEST_SIZE,
+	.init			= crypto_sm3_init,
+	.update			= crypto_sm3_update,
+	.final			= crypto_sm3_final,
+	.digest			= crypto_sm3_digest,
+	.export_core		= crypto_sm3_export_core,
+	.import_core		= crypto_sm3_import_core,
+	.descsize		= sizeof(struct sm3_ctx),
+};
+
+static int __init crypto_sm3_mod_init(void)
+{
+	return crypto_register_shash(&sm3_alg);
+}
+module_init(crypto_sm3_mod_init);
+
+static void __exit crypto_sm3_mod_exit(void)
+{
+	crypto_unregister_shash(&sm3_alg);
+}
+module_exit(crypto_sm3_mod_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Crypto API support for SM3");
+
+MODULE_ALIAS_CRYPTO("sm3");
+MODULE_ALIAS_CRYPTO("sm3-lib");

crypto/sm3_generic.c

@@ -5079,6 +5079,7 @@ static const struct alg_test_desc alg_test_descs[] = {
 		}
 	}, {
 		.alg = "hmac(sm3)",
+		.generic_driver = "hmac(sm3-lib)",
 		.test = alg_test_hash,
 		.suite = {
 			.hash = __VECS(hmac_sm3_tv_template)
@@ -5446,6 +5447,7 @@ static const struct alg_test_desc alg_test_descs[] = {
 		}
 	}, {
 		.alg = "sm3",
+		.generic_driver = "sm3-lib",
 		.test = alg_test_hash,
 		.suite = {
 			.hash = __VECS(sm3_tv_template)

crypto/testmgr.c

@@ -520,7 +520,7 @@ static int starfive_sha512_init_tfm(struct crypto_ahash *hash)
 
 static int starfive_sm3_init_tfm(struct crypto_ahash *hash)
 {
-	return starfive_hash_init_tfm(hash, "sm3-generic",
+	return starfive_hash_init_tfm(hash, "sm3-lib",
 				      STARFIVE_HASH_SM3, 0);
 }
 
@@ -550,7 +550,7 @@ static int starfive_hmac_sha512_init_tfm(struct crypto_ahash *hash)
 
 static int starfive_hmac_sm3_init_tfm(struct crypto_ahash *hash)
 {
-	return starfive_hash_init_tfm(hash, "hmac(sm3-generic)",
+	return starfive_hash_init_tfm(hash, "hmac(sm3-lib)",
 				      STARFIVE_HASH_SM3, 1);
 }