crypto: riscv - add vector crypto accelerated SM4

Add an implementation of SM4 using the Zvksed extension.  The assembly
code is derived from OpenSSL code (openssl/openssl#21923) that was
dual-licensed so that it could be reused in the kernel.  Nevertheless,
the assembly has been significantly reworked for integration with the
kernel, for example by using a regular .S file instead of the so-called
perlasm, using the assembler instead of bare '.inst', and greatly
reducing code duplication.

Co-developed-by: Christoph Müllner <christoph.muellner@vrull.eu>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Co-developed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Signed-off-by: Jerry Shih <jerry.shih@sifive.com>
Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240122002024.27477-11-ebiggers@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/crypto/Kconfig

@@ -73,4 +73,21 @@ config CRYPTO_SM3_RISCV64
 	  - Zvksh vector crypto extension
 	  - Zvkb vector crypto extension
 
+config CRYPTO_SM4_RISCV64
+	tristate "Ciphers: SM4 (ShangMi 4)"
+	depends on 64BIT && RISCV_ISA_V && TOOLCHAIN_HAS_VECTOR_CRYPTO
+	select CRYPTO_ALGAPI
+	select CRYPTO_SM4
+	help
+	  SM4 block cipher algorithm (OSCCA GB/T 32907-2016,
+	  ISO/IEC 18033-3:2010/Amd 1:2021)
+
+	  SM4 (GBT.32907-2016) is a cryptographic standard issued by the
+	  Organization of State Commercial Administration of China (OSCCA)
+	  as an authorized cryptographic algorithm for use within China.
+
+	  Architecture: riscv64 using:
+	  - Zvksed vector crypto extension
+	  - Zvkb vector crypto extension
+
 endmenu

arch/riscv/crypto/Makefile

@@ -18,3 +18,6 @@ sha512-riscv64-y := sha512-riscv64-glue.o sha512-riscv64-zvknhb-zvkb.o
 
 obj-$(CONFIG_CRYPTO_SM3_RISCV64) += sm3-riscv64.o
 sm3-riscv64-y := sm3-riscv64-glue.o sm3-riscv64-zvksh-zvkb.o
+
+obj-$(CONFIG_CRYPTO_SM4_RISCV64) += sm4-riscv64.o
+sm4-riscv64-y := sm4-riscv64-glue.o sm4-riscv64-zvksed-zvkb.o

arch/riscv/crypto/sm4-riscv64-glue.c

@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SM4 using the RISC-V vector crypto extensions
+ *
+ * Copyright (C) 2023 VRULL GmbH
+ * Author: Heiko Stuebner <heiko.stuebner@vrull.eu>
+ *
+ * Copyright (C) 2023 SiFive, Inc.
+ * Author: Jerry Shih <jerry.shih@sifive.com>
+ */
+
+#include <asm/simd.h>
+#include <asm/vector.h>
+#include <crypto/internal/cipher.h>
+#include <crypto/internal/simd.h>
+#include <crypto/sm4.h>
+#include <linux/linkage.h>
+#include <linux/module.h>
+
+asmlinkage void sm4_expandkey_zvksed_zvkb(const u8 user_key[SM4_KEY_SIZE],
+					  u32 rkey_enc[SM4_RKEY_WORDS],
+					  u32 rkey_dec[SM4_RKEY_WORDS]);
+asmlinkage void sm4_crypt_zvksed_zvkb(const u32 rkey[SM4_RKEY_WORDS],
+				      const u8 in[SM4_BLOCK_SIZE],
+				      u8 out[SM4_BLOCK_SIZE]);
+
+static int riscv64_sm4_setkey(struct crypto_tfm *tfm, const u8 *key,
+			      unsigned int keylen)
+{
+	struct sm4_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	if (crypto_simd_usable()) {
+		if (keylen != SM4_KEY_SIZE)
+			return -EINVAL;
+		kernel_vector_begin();
+		sm4_expandkey_zvksed_zvkb(key, ctx->rkey_enc, ctx->rkey_dec);
+		kernel_vector_end();
+		return 0;
+	}
+	return sm4_expandkey(ctx, key, keylen);
+}
+
+static void riscv64_sm4_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+	const struct sm4_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	if (crypto_simd_usable()) {
+		kernel_vector_begin();
+		sm4_crypt_zvksed_zvkb(ctx->rkey_enc, src, dst);
+		kernel_vector_end();
+	} else {
+		sm4_crypt_block(ctx->rkey_enc, dst, src);
+	}
+}
+
+static void riscv64_sm4_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+	const struct sm4_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	if (crypto_simd_usable()) {
+		kernel_vector_begin();
+		sm4_crypt_zvksed_zvkb(ctx->rkey_dec, src, dst);
+		kernel_vector_end();
+	} else {
+		sm4_crypt_block(ctx->rkey_dec, dst, src);
+	}
+}
+
+static struct crypto_alg riscv64_sm4_alg = {
+	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
+	.cra_blocksize = SM4_BLOCK_SIZE,
+	.cra_ctxsize = sizeof(struct sm4_ctx),
+	.cra_priority = 300,
+	.cra_name = "sm4",
+	.cra_driver_name = "sm4-riscv64-zvksed-zvkb",
+	.cra_cipher = {
+		.cia_min_keysize = SM4_KEY_SIZE,
+		.cia_max_keysize = SM4_KEY_SIZE,
+		.cia_setkey = riscv64_sm4_setkey,
+		.cia_encrypt = riscv64_sm4_encrypt,
+		.cia_decrypt = riscv64_sm4_decrypt,
+	},
+	.cra_module = THIS_MODULE,
+};
+
+static int __init riscv64_sm4_mod_init(void)
+{
+	if (riscv_isa_extension_available(NULL, ZVKSED) &&
+	    riscv_isa_extension_available(NULL, ZVKB) &&
+	    riscv_vector_vlen() >= 128)
+		return crypto_register_alg(&riscv64_sm4_alg);
+
+	return -ENODEV;
+}
+
+static void __exit riscv64_sm4_mod_exit(void)
+{
+	crypto_unregister_alg(&riscv64_sm4_alg);
+}
+
+module_init(riscv64_sm4_mod_init);
+module_exit(riscv64_sm4_mod_exit);
+
+MODULE_DESCRIPTION("SM4 (RISC-V accelerated)");
+MODULE_AUTHOR("Heiko Stuebner <heiko.stuebner@vrull.eu>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CRYPTO("sm4");

arch/riscv/crypto/sm4-riscv64-zvksed-zvkb.S

@@ -0,0 +1,117 @@
+/* SPDX-License-Identifier: Apache-2.0 OR BSD-2-Clause */
+//
+// This file is dual-licensed, meaning that you can use it under your
+// choice of either of the following two licenses:
+//
+// Copyright 2023 The OpenSSL Project Authors. All Rights Reserved.
+//
+// Licensed under the Apache License 2.0 (the "License"). You can obtain
+// a copy in the file LICENSE in the source distribution or at
+// https://www.openssl.org/source/license.html
+//
+// or
+//
+// Copyright (c) 2023, Christoph Müllner <christoph.muellner@vrull.eu>
+// Copyright (c) 2023, Jerry Shih <jerry.shih@sifive.com>
+// Copyright 2024 Google LLC
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions
+// are met:
+// 1. Redistributions of source code must retain the above copyright
+//    notice, this list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright
+//    notice, this list of conditions and the following disclaimer in the
+//    documentation and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The generated code of this file depends on the following RISC-V extensions:
+// - RV64I
+// - RISC-V Vector ('V') with VLEN >= 128
+// - RISC-V Vector SM4 Block Cipher extension ('Zvksed')
+// - RISC-V Vector Cryptography Bit-manipulation extension ('Zvkb')
+
+#include <linux/linkage.h>
+
+.text
+.option arch, +zvksed, +zvkb
+
+// void sm4_expandkey_zksed_zvkb(const u8 user_key[16], u32 rkey_enc[32],
+//				 u32 rkey_dec[32]);
+SYM_FUNC_START(sm4_expandkey_zvksed_zvkb)
+	vsetivli	zero, 4, e32, m1, ta, ma
+
+	// Load the user key.
+	vle32.v		v1, (a0)
+	vrev8.v		v1, v1
+
+	// XOR the user key with the family key.
+	la		t0, FAMILY_KEY
+	vle32.v		v2, (t0)
+	vxor.vv		v1, v1, v2
+
+	// Compute the round keys.  Store them in forwards order in rkey_enc
+	// and in reverse order in rkey_dec.
+	addi		a2, a2, 31*4
+	li		t0, -4
+	.set		i, 0
+.rept 8
+	vsm4k.vi	v1, v1, i
+	vse32.v		v1, (a1)	// Store to rkey_enc.
+	vsse32.v	v1, (a2), t0	// Store to rkey_dec.
+.if i < 7
+	addi		a1, a1, 16
+	addi		a2, a2, -16
+.endif
+	.set		i, i + 1
+.endr
+
+	ret
+SYM_FUNC_END(sm4_expandkey_zvksed_zvkb)
+
+// void sm4_crypt_zvksed_zvkb(const u32 rkey[32], const u8 in[16], u8 out[16]);
+SYM_FUNC_START(sm4_crypt_zvksed_zvkb)
+	vsetivli	zero, 4, e32, m1, ta, ma
+
+	// Load the input data.
+	vle32.v		v1, (a1)
+	vrev8.v		v1, v1
+
+	// Do the 32 rounds of SM4, 4 at a time.
+	.set		i, 0
+.rept 8
+	vle32.v		v2, (a0)
+	vsm4r.vs	v1, v2
+.if i < 7
+	addi		a0, a0, 16
+.endif
+	.set		i, i + 1
+.endr
+
+	// Store the output data (in reverse element order).
+	vrev8.v		v1, v1
+	li		t0, -4
+	addi		a2, a2, 12
+	vsse32.v	v1, (a2), t0
+
+	ret
+SYM_FUNC_END(sm4_crypt_zvksed_zvkb)
+
+.section ".rodata"
+.p2align 2
+.type FAMILY_KEY, @object
+FAMILY_KEY:
+	.word 0xA3B1BAC6, 0x56AA3350, 0x677D9197, 0xB27022DC
+.size FAMILY_KEY, . - FAMILY_KEY