crypto: sha256 - support arch-optimized lib and expose through shash

As has been done for various other algorithms, rework the design of the
SHA-256 library to support arch-optimized implementations, and make
crypto/sha256.c expose both generic and arch-optimized shash algorithms
that wrap the library functions.

This allows users of the SHA-256 library functions to take advantage of
the arch-optimized code, and this makes it much simpler to integrate
SHA-256 for each architecture.

Note that sha256_base.h is not used in the new design.  It will be
removed once all the architecture-specific code has been updated.

Move the generic block function into its own module to avoid a circular
dependency from libsha256.ko => sha256-$ARCH.ko => libsha256.ko.

Signed-off-by: Eric Biggers <ebiggers@google.com>

Add export and import functions to maintain existing export format.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

4 files changed, 246 insertions, 103 deletions

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 3cb5563dc4ab..7bfad077f308 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -982,6 +982,7 @@ config CRYPTO_SHA256
 	tristate "SHA-224 and SHA-256"
 	select CRYPTO_HASH
 	select CRYPTO_LIB_SHA256
+	select CRYPTO_LIB_SHA256_GENERIC
 	help
 	  SHA-224 and SHA-256 secure hash algorithms (FIPS 180, ISO/IEC 10118-3)
 
diff --git a/crypto/Makefile b/crypto/Makefile
index 587bc74b6d74..84f6911dc9ba 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -76,7 +76,8 @@ obj-$(CONFIG_CRYPTO_MD4) += md4.o
 obj-$(CONFIG_CRYPTO_MD5) += md5.o
 obj-$(CONFIG_CRYPTO_RMD160) += rmd160.o
 obj-$(CONFIG_CRYPTO_SHA1) += sha1_generic.o
-obj-$(CONFIG_CRYPTO_SHA256) += sha256_generic.o
+obj-$(CONFIG_CRYPTO_SHA256) += sha256.o
+CFLAGS_sha256.o += -DARCH=$(ARCH)
 obj-$(CONFIG_CRYPTO_SHA512) += sha512_generic.o
 obj-$(CONFIG_CRYPTO_SHA3) += sha3_generic.o
 obj-$(CONFIG_CRYPTO_SM3_GENERIC) += sm3_generic.o
diff --git a/crypto/sha256.c b/crypto/sha256.c
new file mode 100644
index 000000000000..c2588d08ee3e
--- /dev/null
+++ b/crypto/sha256.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Crypto API wrapper for the SHA-256 and SHA-224 library functions
+ *
+ * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
+ * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
+ * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ * SHA224 Support Copyright 2007 Intel Corporation <jonathan.lynch@intel.com>
+ */
+#include <crypto/internal/hash.h>
+#include <crypto/internal/sha2.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+const u8 sha224_zero_message_hash[SHA224_DIGEST_SIZE] = {
+	0xd1, 0x4a, 0x02, 0x8c, 0x2a, 0x3a, 0x2b, 0xc9, 0x47,
+	0x61, 0x02, 0xbb, 0x28, 0x82, 0x34, 0xc4, 0x15, 0xa2,
+	0xb0, 0x1f, 0x82, 0x8e, 0xa6, 0x2a, 0xc5, 0xb3, 0xe4,
+	0x2f
+};
+EXPORT_SYMBOL_GPL(sha224_zero_message_hash);
+
+const u8 sha256_zero_message_hash[SHA256_DIGEST_SIZE] = {
+	0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14,
+	0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24,
+	0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c,
+	0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55
+};
+EXPORT_SYMBOL_GPL(sha256_zero_message_hash);
+
+static int crypto_sha256_init(struct shash_desc *desc)
+{
+	sha256_init(shash_desc_ctx(desc));
+	return 0;
+}
+
+static int crypto_sha256_update_generic(struct shash_desc *desc, const u8 *data,
+					unsigned int len)
+{
+	sha256_update_generic(shash_desc_ctx(desc), data, len);
+	return 0;
+}
+
+static int crypto_sha256_update_arch(struct shash_desc *desc, const u8 *data,
+				     unsigned int len)
+{
+	sha256_update(shash_desc_ctx(desc), data, len);
+	return 0;
+}
+
+static int crypto_sha256_final_generic(struct shash_desc *desc, u8 *out)
+{
+	sha256_final_generic(shash_desc_ctx(desc), out);
+	return 0;
+}
+
+static int crypto_sha256_final_arch(struct shash_desc *desc, u8 *out)
+{
+	sha256_final(shash_desc_ctx(desc), out);
+	return 0;
+}
+
+static int crypto_sha256_finup_generic(struct shash_desc *desc, const u8 *data,
+				       unsigned int len, u8 *out)
+{
+	struct sha256_state *sctx = shash_desc_ctx(desc);
+
+	sha256_update_generic(sctx, data, len);
+	sha256_final_generic(sctx, out);
+	return 0;
+}
+
+static int crypto_sha256_finup_arch(struct shash_desc *desc, const u8 *data,
+				    unsigned int len, u8 *out)
+{
+	struct sha256_state *sctx = shash_desc_ctx(desc);
+
+	sha256_update(sctx, data, len);
+	sha256_final(sctx, out);
+	return 0;
+}
+
+static int crypto_sha256_digest_generic(struct shash_desc *desc, const u8 *data,
+					unsigned int len, u8 *out)
+{
+	struct sha256_state *sctx = shash_desc_ctx(desc);
+
+	sha256_init(sctx);
+	sha256_update_generic(sctx, data, len);
+	sha256_final_generic(sctx, out);
+	return 0;
+}
+
+static int crypto_sha256_digest_arch(struct shash_desc *desc, const u8 *data,
+				     unsigned int len, u8 *out)
+{
+	sha256(data, len, out);
+	return 0;
+}
+
+static int crypto_sha224_init(struct shash_desc *desc)
+{
+	sha224_init(shash_desc_ctx(desc));
+	return 0;
+}
+
+static int crypto_sha224_final_generic(struct shash_desc *desc, u8 *out)
+{
+	sha224_final_generic(shash_desc_ctx(desc), out);
+	return 0;
+}
+
+static int crypto_sha224_final_arch(struct shash_desc *desc, u8 *out)
+{
+	sha224_final(shash_desc_ctx(desc), out);
+	return 0;
+}
+
+static int crypto_sha256_import_lib(struct shash_desc *desc, const void *in)
+{
+	struct sha256_state *sctx = shash_desc_ctx(desc);
+	const u8 *p = in;
+
+	memcpy(sctx, p, sizeof(*sctx));
+	p += sizeof(*sctx);
+	sctx->count += *p;
+	return 0;
+}
+
+static int crypto_sha256_export_lib(struct shash_desc *desc, void *out)
+{
+	struct sha256_state *sctx0 = shash_desc_ctx(desc);
+	struct sha256_state sctx = *sctx0;
+	unsigned int partial;
+	u8 *p = out;
+
+	partial = sctx.count % SHA256_BLOCK_SIZE;
+	sctx.count -= partial;
+	memcpy(p, &sctx, sizeof(sctx));
+	p += sizeof(sctx);
+	*p = partial;
+	return 0;
+}
+
+static struct shash_alg algs[] = {
+	{
+		.base.cra_name		= "sha256",
+		.base.cra_driver_name	= "sha256-generic",
+		.base.cra_priority	= 100,
+		.base.cra_blocksize	= SHA256_BLOCK_SIZE,
+		.base.cra_module	= THIS_MODULE,
+		.digestsize		= SHA256_DIGEST_SIZE,
+		.init			= crypto_sha256_init,
+		.update			= crypto_sha256_update_generic,
+		.final			= crypto_sha256_final_generic,
+		.finup			= crypto_sha256_finup_generic,
+		.digest			= crypto_sha256_digest_generic,
+		.descsize		= sizeof(struct sha256_state),
+		.statesize		= sizeof(struct crypto_sha256_state) +
+					  SHA256_BLOCK_SIZE + 1,
+		.import			= crypto_sha256_import_lib,
+		.export			= crypto_sha256_export_lib,
+	},
+	{
+		.base.cra_name		= "sha224",
+		.base.cra_driver_name	= "sha224-generic",
+		.base.cra_priority	= 100,
+		.base.cra_blocksize	= SHA224_BLOCK_SIZE,
+		.base.cra_module	= THIS_MODULE,
+		.digestsize		= SHA224_DIGEST_SIZE,
+		.init			= crypto_sha224_init,
+		.update			= crypto_sha256_update_generic,
+		.final			= crypto_sha224_final_generic,
+		.descsize		= sizeof(struct sha256_state),
+		.statesize		= sizeof(struct crypto_sha256_state) +
+					  SHA256_BLOCK_SIZE + 1,
+		.import			= crypto_sha256_import_lib,
+		.export			= crypto_sha256_export_lib,
+	},
+	{
+		.base.cra_name		= "sha256",
+		.base.cra_driver_name	= "sha256-" __stringify(ARCH),
+		.base.cra_priority	= 300,
+		.base.cra_blocksize	= SHA256_BLOCK_SIZE,
+		.base.cra_module	= THIS_MODULE,
+		.digestsize		= SHA256_DIGEST_SIZE,
+		.init			= crypto_sha256_init,
+		.update			= crypto_sha256_update_arch,
+		.final			= crypto_sha256_final_arch,
+		.finup			= crypto_sha256_finup_arch,
+		.digest			= crypto_sha256_digest_arch,
+		.descsize		= sizeof(struct sha256_state),
+		.statesize		= sizeof(struct crypto_sha256_state) +
+					  SHA256_BLOCK_SIZE + 1,
+		.import			= crypto_sha256_import_lib,
+		.export			= crypto_sha256_export_lib,
+	},
+	{
+		.base.cra_name		= "sha224",
+		.base.cra_driver_name	= "sha224-" __stringify(ARCH),
+		.base.cra_priority	= 300,
+		.base.cra_blocksize	= SHA224_BLOCK_SIZE,
+		.base.cra_module	= THIS_MODULE,
+		.digestsize		= SHA224_DIGEST_SIZE,
+		.init			= crypto_sha224_init,
+		.update			= crypto_sha256_update_arch,
+		.final			= crypto_sha224_final_arch,
+		.descsize		= sizeof(struct sha256_state),
+		.statesize		= sizeof(struct crypto_sha256_state) +
+					  SHA256_BLOCK_SIZE + 1,
+		.import			= crypto_sha256_import_lib,
+		.export			= crypto_sha256_export_lib,
+	},
+};
+
+static unsigned int num_algs;
+
+static int __init crypto_sha256_mod_init(void)
+{
+	/* register the arch flavours only if they differ from generic */
+	num_algs = ARRAY_SIZE(algs);
+	BUILD_BUG_ON(ARRAY_SIZE(algs) % 2 != 0);
+	if (!sha256_is_arch_optimized())
+		num_algs /= 2;
+	return crypto_register_shashes(algs, ARRAY_SIZE(algs));
+}
+subsys_initcall(crypto_sha256_mod_init);
+
+static void __exit crypto_sha256_mod_exit(void)
+{
+	crypto_unregister_shashes(algs, num_algs);
+}
+module_exit(crypto_sha256_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Crypto API wrapper for the SHA-256 and SHA-224 library functions");
+
+MODULE_ALIAS_CRYPTO("sha256");
+MODULE_ALIAS_CRYPTO("sha256-generic");
+MODULE_ALIAS_CRYPTO("sha256-" __stringify(ARCH));
+MODULE_ALIAS_CRYPTO("sha224");
+MODULE_ALIAS_CRYPTO("sha224-generic");
+MODULE_ALIAS_CRYPTO("sha224-" __stringify(ARCH));
diff --git a/crypto/sha256_generic.c b/crypto/sha256_generic.c
deleted file mode 100644
index 05084e5bbaec..000000000000
--- a/crypto/sha256_generic.c
+++ /dev/null
@@ -1,102 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Crypto API wrapper for the generic SHA256 code from lib/crypto/sha256.c
- *
- * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
- * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
- * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
- * SHA224 Support Copyright 2007 Intel Corporation <jonathan.lynch@intel.com>
- */
-#include <crypto/internal/hash.h>
-#include <crypto/sha2.h>
-#include <crypto/sha256_base.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-
-const u8 sha224_zero_message_hash[SHA224_DIGEST_SIZE] = {
-	0xd1, 0x4a, 0x02, 0x8c, 0x2a, 0x3a, 0x2b, 0xc9, 0x47,
-	0x61, 0x02, 0xbb, 0x28, 0x82, 0x34, 0xc4, 0x15, 0xa2,
-	0xb0, 0x1f, 0x82, 0x8e, 0xa6, 0x2a, 0xc5, 0xb3, 0xe4,
-	0x2f
-};
-EXPORT_SYMBOL_GPL(sha224_zero_message_hash);
-
-const u8 sha256_zero_message_hash[SHA256_DIGEST_SIZE] = {
-	0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14,
-	0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24,
-	0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c,
-	0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55
-};
-EXPORT_SYMBOL_GPL(sha256_zero_message_hash);
-
-static void sha256_block(struct crypto_sha256_state *sctx, const u8 *input,
-			 int blocks)
-{
-	sha256_transform_blocks(sctx, input, blocks);
-}
-
-static int crypto_sha256_update(struct shash_desc *desc, const u8 *data,
-				unsigned int len)
-{
-	return sha256_base_do_update_blocks(desc, data, len, sha256_block);
-}
-
-static int crypto_sha256_finup(struct shash_desc *desc, const u8 *data,
-			       unsigned int len, u8 *hash)
-{
-	sha256_base_do_finup(desc, data, len, sha256_block);
-	return sha256_base_finish(desc, hash);
-}
-
-static struct shash_alg sha256_algs[2] = { {
-	.digestsize	=	SHA256_DIGEST_SIZE,
-	.init		=	sha256_base_init,
-	.update		=	crypto_sha256_update,
-	.finup		=	crypto_sha256_finup,
-	.descsize	=	sizeof(struct crypto_sha256_state),
-	.base		=	{
-		.cra_name	=	"sha256",
-		.cra_driver_name=	"sha256-generic",
-		.cra_priority	=	100,
-		.cra_flags	=	CRYPTO_AHASH_ALG_BLOCK_ONLY |
-					CRYPTO_AHASH_ALG_FINUP_MAX,
-		.cra_blocksize	=	SHA256_BLOCK_SIZE,
-		.cra_module	=	THIS_MODULE,
-	}
-}, {
-	.digestsize	=	SHA224_DIGEST_SIZE,
-	.init		=	sha224_base_init,
-	.update		=	crypto_sha256_update,
-	.finup		=	crypto_sha256_finup,
-	.descsize	=	sizeof(struct crypto_sha256_state),
-	.base		=	{
-		.cra_name	=	"sha224",
-		.cra_driver_name=	"sha224-generic",
-		.cra_priority	=	100,
-		.cra_flags	=	CRYPTO_AHASH_ALG_BLOCK_ONLY |
-					CRYPTO_AHASH_ALG_FINUP_MAX,
-		.cra_blocksize	=	SHA224_BLOCK_SIZE,
-		.cra_module	=	THIS_MODULE,
-	}
-} };
-
-static int __init sha256_generic_mod_init(void)
-{
-	return crypto_register_shashes(sha256_algs, ARRAY_SIZE(sha256_algs));
-}
-
-static void __exit sha256_generic_mod_fini(void)
-{
-	crypto_unregister_shashes(sha256_algs, ARRAY_SIZE(sha256_algs));
-}
-
-subsys_initcall(sha256_generic_mod_init);
-module_exit(sha256_generic_mod_fini);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("SHA-224 and SHA-256 Secure Hash Algorithm");
-
-MODULE_ALIAS_CRYPTO("sha224");
-MODULE_ALIAS_CRYPTO("sha224-generic");
-MODULE_ALIAS_CRYPTO("sha256");
-MODULE_ALIAS_CRYPTO("sha256-generic");