[1/2] crypto: introduce SM4 symmetric cipher algorithm

diff --git a/crypto/Kconfig b/crypto/Kconfig
index de693e0..4b8df3a 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1475,6 +1475,31 @@  config CRYPTO_SERPENT_AVX2_X86_64
 	  See also:
 	  <http://www.cl.cam.ac.uk/~rja14/serpent.html>
 
+config CRYPTO_SM4
+	tristate "SM4 cipher algorithm"
+	select CRYPTO_ALGAPI
+	help
+	  SM4 cipher algorithms (OSCCA GB/T 32907-2016).
+
+	  SM4 (GBT.32907-2016) is a cryptographic standard issued by the
+	  Organization of State Commercial Administration of China (OSCCA)
+	  as an authorized cryptographic algorithms for the use within China.
+
+	  SMS4 was originally created for use in protecting wireless
+	  networks, and is mandated in the Chinese National Standard for
+	  Wireless LAN WAPI (Wired Authentication and Privacy Infrastructure)
+	  (GB.15629.11-2003).
+
+	  The latest SM4 standard (GBT.32907-2016) was proposed by OSCCA and
+	  standardized through TC 260 of the Standardization Administration
+	  of the People's Republic of China (SAC).
+
+	  The input, output, and key of SMS4 are each 128 bits.
+
+	  See also: <https://eprint.iacr.org/2008/329.pdf>
+
+	  If unsure, say N.
+
 config CRYPTO_SPECK
 	tristate "Speck cipher algorithm"
 	select CRYPTO_ALGAPI
diff --git a/crypto/Makefile b/crypto/Makefile
index 04517b2..eb4d9cd 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -100,6 +100,7 @@  obj-$(CONFIG_CRYPTO_SERPENT) += serpent_generic.o
 CFLAGS_serpent_generic.o := $(call cc-option,-fsched-pressure)  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79149
 obj-$(CONFIG_CRYPTO_AES) += aes_generic.o
 CFLAGS_aes_generic.o := $(call cc-option,-fno-code-hoisting) # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83356
+obj-$(CONFIG_CRYPTO_SM4) += sm4_generic.o
 obj-$(CONFIG_CRYPTO_AES_TI) += aes_ti.o
 obj-$(CONFIG_CRYPTO_CAMELLIA) += camellia_generic.o
 obj-$(CONFIG_CRYPTO_CAST_COMMON) += cast_common.o
diff --git a/crypto/sm4_generic.c b/crypto/sm4_generic.c
new file mode 100644
index 0000000..f537a27
--- /dev/null
+++ b/crypto/sm4_generic.c
@@ -0,0 +1,244 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * SM4 Cipher Algorithm.
+ *
+ * Copyright (C) 2018 ARM Limited or its affiliates.
+ * All rights reserved.
+ */
+
+#include <crypto/sm4.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/crypto.h>
+#include <asm/byteorder.h>
+#include <asm/unaligned.h>
+
+static const u32 fk[4] = {
+	0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc
+};
+
+static const u8 sbox[256] = {
+	0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7,
+	0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05,
+	0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3,
+	0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99,
+	0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a,
+	0x33, 0x54, 0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62,
+	0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95,
+	0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f, 0xa6,
+	0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba,
+	0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8,
+	0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b,
+	0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35,
+	0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2,
+	0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87,
+	0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52,
+	0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e,
+	0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5,
+	0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1,
+	0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34, 0x1a, 0x55,
+	0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3,
+	0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60,
+	0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f,
+	0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f,
+	0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51,
+	0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f,
+	0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8,
+	0x0a, 0xc1, 0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd,
+	0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0,
+	0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e,
+	0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84,
+	0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20,
+	0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48
+};
+
+static const u32 ck[] = {
+	0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
+	0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
+	0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
+	0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
+	0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
+	0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
+	0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
+	0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
+};
+
+static u32 sm4_t_non_lin_sub(u32 x)
+{
+	int i;
+	u8 *b = (u8 *)&x;
+
+	for (i = 0; i < 4; ++i)
+		b[i] = sbox[b[i]];
+
+	return x;
+}
+
+static u32 sm4_key_lin_sub(u32 x)
+{
+	return x ^ rol32(x, 13) ^ rol32(x, 23);
+
+}
+
+static u32 sm4_enc_lin_sub(u32 x)
+{
+	return x ^ rol32(x, 2) ^ rol32(x, 10) ^ rol32(x, 18) ^ rol32(x, 24);
+}
+
+static u32 sm4_key_sub(u32 x)
+{
+	return sm4_key_lin_sub(sm4_t_non_lin_sub(x));
+}
+
+static u32 sm4_enc_sub(u32 x)
+{
+	return sm4_enc_lin_sub(sm4_t_non_lin_sub(x));
+}
+
+static u32 sm4_round(const u32 *x, const u32 rk)
+{
+	return x[0] ^ sm4_enc_sub(x[1] ^ x[2] ^ x[3] ^ rk);
+}
+
+
+/**
+ * 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)
+{
+	u32 rk[4], t;
+	const u32 *key = (u32 *)in_key;
+	int i;
+
+	if (key_len != SM4_KEY_SIZE)
+		return -EINVAL;
+
+	for (i = 0; i < 4; ++i)
+		rk[i] = get_unaligned_be32(&key[i]) ^ fk[i];
+
+	for (i = 0; i < 32; ++i) {
+		t = rk[0] ^ sm4_key_sub(rk[1] ^ rk[2] ^ rk[3] ^ ck[i]);
+		ctx->rkey_enc[i] = t;
+		rk[0] = rk[1];
+		rk[1] = rk[2];
+		rk[2] = rk[3];
+		rk[3] = t;
+	}
+
+	for (i = 0; i < 32; ++i)
+		ctx->rkey_dec[i] = ctx->rkey_enc[31 - i];
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(crypto_sm4_expand_key);
+
+/**
+ * crypto_sm4_set_key - Set the AES key.
+ * @tfm:	The %crypto_tfm that is used in the context.
+ * @in_key:	The input key.
+ * @key_len:	The size of the key.
+ *
+ * Returns 0 on success, on failure the %CRYPTO_TFM_RES_BAD_KEY_LEN flag in tfm
+ * is set. The function uses crypto_sm4_expand_key() to expand the key.
+ * &crypto_sm4_ctx _must_ be the private data embedded in @tfm which is
+ * retrieved with crypto_tfm_ctx().
+ */
+int crypto_sm4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
+		       unsigned int key_len)
+{
+	struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm);
+	u32 *flags = &tfm->crt_flags;
+	int ret;
+
+	ret = crypto_sm4_expand_key(ctx, in_key, key_len);
+	if (!ret)
+		return 0;
+
+	*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(crypto_sm4_set_key);
+
+static void sm4_do_crypt(const u32 *rk, u32 *out, const u32 *in)
+{
+	u32 x[4], i, t;
+
+	for (i = 0; i < 4; ++i)
+		x[i] = get_unaligned_be32(&in[i]);
+
+	for (i = 0; i < 32; ++i) {
+		t = sm4_round(x, rk[i]);
+		x[0] = x[1];
+		x[1] = x[2];
+		x[2] = x[3];
+		x[3] = t;
+	}
+
+	for (i = 0; i < 4; ++i)
+		put_unaligned_be32(x[3 - i], &out[i]);
+}
+
+/* encrypt a block of text */
+
+static void sm4_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
+{
+	const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	sm4_do_crypt(ctx->rkey_enc, (u32 *)out, (u32 *)in);
+}
+
+/* decrypt a block of text */
+
+static void sm4_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
+{
+	const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	sm4_do_crypt(ctx->rkey_dec, (u32 *)out, (u32 *)in);
+}
+
+static struct crypto_alg sm4_alg = {
+	.cra_name		=	"sm4",
+	.cra_driver_name	=	"sm4-generic",
+	.cra_priority		=	100,
+	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
+	.cra_blocksize		=	SM4_BLOCK_SIZE,
+	.cra_ctxsize		=	sizeof(struct crypto_sm4_ctx),
+	.cra_module		=	THIS_MODULE,
+	.cra_u			=	{
+		.cipher = {
+			.cia_min_keysize	=	SM4_KEY_SIZE,
+			.cia_max_keysize	=	SM4_KEY_SIZE,
+			.cia_setkey		=	crypto_sm4_set_key,
+			.cia_encrypt		=	sm4_encrypt,
+			.cia_decrypt		=	sm4_decrypt
+		}
+	}
+};
+
+static int __init sm4_init(void)
+{
+	return crypto_register_alg(&sm4_alg);
+}
+
+static void __exit sm4_fini(void)
+{
+	crypto_unregister_alg(&sm4_alg);
+}
+
+module_init(sm4_init);
+module_exit(sm4_fini);
+
+MODULE_DESCRIPTION("SM4 Cipher Algorithm");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_CRYPTO("sm4");
+MODULE_ALIAS_CRYPTO("sm4-generic");
diff --git a/include/crypto/sm4.h b/include/crypto/sm4.h
new file mode 100644
index 0000000..b64e64d
--- /dev/null
+++ b/include/crypto/sm4.h
@@ -0,0 +1,28 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Common values for the SM4 algorithm
+ * Copyright (C) 2018 ARM Limited or its affiliates.
+ */
+
+#ifndef _CRYPTO_SM4_H
+#define _CRYPTO_SM4_H
+
+#include <linux/types.h>
+#include <linux/crypto.h>
+
+#define SM4_KEY_SIZE	16
+#define SM4_BLOCK_SIZE	16
+#define SM4_RKEY_WORDS	32
+
+struct crypto_sm4_ctx {
+	u32 rkey_enc[SM4_RKEY_WORDS];
+	u32 rkey_dec[SM4_RKEY_WORDS];
+};
+
+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,
+			  unsigned int key_len);
+
+#endif