2026-01-29 22:25:33 +08:00

159 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SM2 asymmetric public-key algorithm
* as specified by OSCCA GM/T 0003.1-2012 -- 0003.5-2012 SM2 and
* described at https://tools.ietf.org/html/draft-shen-sm2-ecdsa-02
*
* Copyright (c) 2023 Shanghai Zhaoxin Semiconductor LTD.
* Authors: YunShen <yunshen@zhaoxin.com>
*/
#include <linux/module.h>
#include <linux/mpi.h>
#include <crypto/internal/akcipher.h>
#include <crypto/akcipher.h>
#include <crypto/sm2.h>
#include <asm/cpufeature.h>
#include <asm/processor.h>
#include <asm/cpu_device_id.h>
#define SCRATCH_SIZE (4 * 2048)
#define SM2_CWORD_VERIFY 0x8
#define SM2_VERIFY_PASS 1
struct sm2_cipher_data {
u8 pub_key[65]; /* public key */
};
/* Load supported features of the CPU to see if the SM2 is available. */
static int zhaoxin_gmi_available(void)
{
if (!boot_cpu_has(X86_FEATURE_SM2_EN)) {
pr_err("can't enable hardware SM2 if Zhaoxin GMI SM2 is not enabled\n");
return -ENODEV;
}
return 0;
}
/* Zhaoxin sm2 verify function */
static inline size_t zhaoxin_gmi_sm2_verify(unsigned char *key, unsigned char *hash,
unsigned char *sig, unsigned char *scratch)
{
size_t result;
asm volatile(
".byte 0xf2, 0x0f, 0xa6, 0xc0"
: "=c"(result)
: "a"(hash), "b"(key), "d"(SM2_CWORD_VERIFY), "S"(scratch), "D"(sig)
: "memory");
return result;
}
/* Zhaoxin sm2 verify function */
static int _zhaoxin_sm2_verify(struct sm2_cipher_data *ec, unsigned char *hash, unsigned char *sig)
{
unsigned char *scratch = kzalloc(SCRATCH_SIZE, GFP_KERNEL);
int ret = -EKEYREJECTED;
size_t result;
result = zhaoxin_gmi_sm2_verify(ec->pub_key, hash, sig, scratch);
if (result == SM2_VERIFY_PASS)
ret = 0;
kfree(scratch);
return ret;
}
static int zhaoxin_sm2_verify(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
struct sm2_cipher_data *ec = akcipher_tfm_ctx(tfm);
unsigned char *buffer;
int ret, buf_len;
buf_len = req->src_len + req->dst_len;
buffer = kmalloc(buf_len, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
sg_pcopy_to_buffer(req->src, sg_nents_for_len(req->src, buf_len), buffer, buf_len, 0);
ret = _zhaoxin_sm2_verify(ec, buffer + req->src_len, buffer);
kfree(buffer);
return ret;
}
static int zhaoxin_sm2_set_pub_key(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen)
{
struct sm2_cipher_data *ec = akcipher_tfm_ctx(tfm);
memcpy(ec->pub_key, key, keylen);
return 0;
}
static unsigned int zhaoxin_sm2_max_size(struct crypto_akcipher *tfm)
{
/* Unlimited max size */
return PAGE_SIZE;
}
static int zhaoxin_sm2_init_tfm(struct crypto_akcipher *tfm)
{
return zhaoxin_gmi_available();
}
static void zhaoxin_sm2_exit_tfm(struct crypto_akcipher *tfm)
{
struct sm2_cipher_data *ec = akcipher_tfm_ctx(tfm);
memset(ec, 0, sizeof(*ec));
}
static struct akcipher_alg zhaoxin_sm2 = {
.verify = zhaoxin_sm2_verify,
.set_pub_key = zhaoxin_sm2_set_pub_key,
.max_size = zhaoxin_sm2_max_size,
.init = zhaoxin_sm2_init_tfm,
.exit = zhaoxin_sm2_exit_tfm,
.base = {
.cra_name = "sm2",
.cra_driver_name = "zhaoxin-gmi-sm2",
.cra_priority = 150,
.cra_module = THIS_MODULE,
.cra_ctxsize = sizeof(struct sm2_cipher_data),
},
};
static const struct x86_cpu_id zhaoxin_sm2_cpu_ids[] = {
X86_MATCH_FEATURE(X86_FEATURE_SM2, NULL),
{}
};
MODULE_DEVICE_TABLE(x86cpu, zhaoxin_sm2_cpu_ids);
static int __init zhaoxin_sm2_init(void)
{
if (!x86_match_cpu(zhaoxin_sm2_cpu_ids))
return -ENODEV;
return crypto_register_akcipher(&zhaoxin_sm2);
}
static void __exit zhaoxin_sm2_exit(void)
{
crypto_unregister_akcipher(&zhaoxin_sm2);
}
module_init(zhaoxin_sm2_init);
module_exit(zhaoxin_sm2_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("YunShen <yunshen@zhaoxin.com>");
MODULE_DESCRIPTION("SM2 Zhaoxin GMI Algorithm");
MODULE_ALIAS_CRYPTO("zhaoxin-gmi-sm2");