mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-02 17:41:08 +00:00
ee870859ce
The STM32MP ROM provides several service. One of them is the ability to verify ecdsa256 signatures. Hook the ROM API into the ECDSA uclass. Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
102 lines
2.7 KiB
C
102 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* STM32MP ECDSA verification via the ROM API
|
|
*
|
|
* Implements ECDSA signature verification via the STM32MP ROM.
|
|
*/
|
|
#include <asm/system.h>
|
|
#include <dm/device.h>
|
|
#include <linux/types.h>
|
|
#include <u-boot/ecdsa.h>
|
|
#include <crypto/ecdsa-uclass.h>
|
|
#include <linux/libfdt.h>
|
|
#include <dm/platdata.h>
|
|
|
|
#define ROM_API_SUCCESS 0x77
|
|
#define ROM_API_ECDSA_ALGO_PRIME_256V1 1
|
|
#define ROM_API_ECDSA_ALGO_BRAINPOOL_256 2
|
|
|
|
#define ROM_API_OFFSET_ECDSA_VERIFY 0x60
|
|
|
|
struct ecdsa_rom_api {
|
|
uint32_t (*ecdsa_verify_signature)(const void *hash, const void *pubkey,
|
|
const void *signature,
|
|
uint32_t ecc_algo);
|
|
};
|
|
|
|
/*
|
|
* Without forcing the ".data" section, this would get saved in ".bss". BSS
|
|
* will be cleared soon after, so it's not suitable.
|
|
*/
|
|
static uintptr_t rom_api_loc __section(".data");
|
|
|
|
/*
|
|
* The ROM gives us the API location in r0 when starting. This is only available
|
|
* during SPL, as there isn't (yet) a mechanism to pass this on to u-boot.
|
|
*/
|
|
void save_boot_params(unsigned long r0, unsigned long r1, unsigned long r2,
|
|
unsigned long r3)
|
|
{
|
|
rom_api_loc = r0;
|
|
save_boot_params_ret();
|
|
}
|
|
|
|
static void stm32mp_rom_get_ecdsa_functions(struct ecdsa_rom_api *rom)
|
|
{
|
|
uintptr_t verify_ptr = rom_api_loc + ROM_API_OFFSET_ECDSA_VERIFY;
|
|
|
|
rom->ecdsa_verify_signature = *(void **)verify_ptr;
|
|
}
|
|
|
|
static int ecdsa_key_algo(const char *curve_name)
|
|
{
|
|
if (!strcmp(curve_name, "prime256v1"))
|
|
return ROM_API_ECDSA_ALGO_PRIME_256V1;
|
|
else if (!strcmp(curve_name, "brainpool256"))
|
|
return ROM_API_ECDSA_ALGO_BRAINPOOL_256;
|
|
else
|
|
return -ENOPROTOOPT;
|
|
}
|
|
|
|
static int romapi_ecdsa_verify(struct udevice *dev,
|
|
const struct ecdsa_public_key *pubkey,
|
|
const void *hash, size_t hash_len,
|
|
const void *signature, size_t sig_len)
|
|
{
|
|
struct ecdsa_rom_api rom;
|
|
uint8_t raw_key[64];
|
|
uint32_t rom_ret;
|
|
int algo;
|
|
|
|
/* The ROM API can only handle 256-bit ECDSA keys. */
|
|
if (sig_len != 64 || hash_len != 32 || pubkey->size_bits != 256)
|
|
return -EINVAL;
|
|
|
|
algo = ecdsa_key_algo(pubkey->curve_name);
|
|
if (algo < 0)
|
|
return algo;
|
|
|
|
/* The ROM API wants the (X, Y) coordinates concatenated. */
|
|
memcpy(raw_key, pubkey->x, 32);
|
|
memcpy(raw_key + 32, pubkey->y, 32);
|
|
|
|
stm32mp_rom_get_ecdsa_functions(&rom);
|
|
rom_ret = rom.ecdsa_verify_signature(hash, raw_key, signature, algo);
|
|
|
|
return rom_ret == ROM_API_SUCCESS ? 0 : -EPERM;
|
|
}
|
|
|
|
static const struct ecdsa_ops rom_api_ops = {
|
|
.verify = romapi_ecdsa_verify,
|
|
};
|
|
|
|
U_BOOT_DRIVER(stm32mp_rom_api_ecdsa) = {
|
|
.name = "stm32mp_rom_api_ecdsa",
|
|
.id = UCLASS_ECDSA,
|
|
.ops = &rom_api_ops,
|
|
.flags = DM_FLAG_PRE_RELOC,
|
|
};
|
|
|
|
U_BOOT_DRVINFO(stm32mp_rom_api_ecdsa) = {
|
|
.name = "stm32mp_rom_api_ecdsa",
|
|
};
|