[PATCH v3] imx: ele_ahab: Add HUK derivation support
Mathieu Othacehe
othacehe at gnu.org
Mon Aug 26 12:07:07 CEST 2024
Add a new ahab_derive command that derives the hardware unique key (HUK)
into a 16 or 32 bytes key and stores it at the given address.
Signed-off-by: Mathieu Othacehe <othacehe at gnu.org>
---
Changelog:
v2:
Make the seed size configurable
v3:
Fix a typo char* seed -> char seed[]
Rebase on top of u-boot next
arch/arm/include/asm/mach-imx/ele_api.h | 2 +
arch/arm/mach-imx/ele_ahab.c | 31 ++++++++++
drivers/misc/imx_ele/ele_api.c | 77 +++++++++++++++++++++++++
3 files changed, 110 insertions(+)
diff --git a/arch/arm/include/asm/mach-imx/ele_api.h b/arch/arm/include/asm/mach-imx/ele_api.h
index a29b849d903..d4ac567e7ed 100644
--- a/arch/arm/include/asm/mach-imx/ele_api.h
+++ b/arch/arm/include/asm/mach-imx/ele_api.h
@@ -26,6 +26,7 @@
#define ELE_GET_EVENTS_REQ (0xA2)
#define ELE_COMMIT_REQ (0xA8)
#define ELE_START_RNG (0xA3)
+#define ELE_CMD_DERIVE_KEY (0xA9)
#define ELE_GENERATE_DEK_BLOB (0xAF)
#define ELE_ENABLE_PATCH_REQ (0xC3)
#define ELE_RELEASE_RDC_REQ (0xC4)
@@ -143,6 +144,7 @@ int ele_read_common_fuse(u16 fuse_id, u32 *fuse_words, u32 fuse_num, u32 *respon
int ele_release_caam(u32 core_did, u32 *response);
int ele_get_fw_version(u32 *fw_version, u32 *sha1, u32 *response);
int ele_get_events(u32 *events, u32 *events_cnt, u32 *response);
+int ele_derive_huk(u8 *key, size_t key_size, u8 *ctx, size_t seed_size);
int ele_commit(u16 fuse_id, u32 *response, u32 *info_type);
int ele_generate_dek_blob(u32 key_id, u32 src_paddr, u32 dst_paddr, u32 max_output_size);
int ele_dump_buffer(u32 *buffer, u32 buffer_length);
diff --git a/arch/arm/mach-imx/ele_ahab.c b/arch/arm/mach-imx/ele_ahab.c
index c13d9f0e00e..647daeb6562 100644
--- a/arch/arm/mach-imx/ele_ahab.c
+++ b/arch/arm/mach-imx/ele_ahab.c
@@ -624,6 +624,31 @@ static int do_ahab_return_lifecycle(struct cmd_tbl *cmdtp, int flag, int argc, c
return CMD_RET_SUCCESS;
}
+static int do_ahab_derive(struct cmd_tbl *cmdtp, int flag, int argc,
+ char *const argv[])
+{
+ ulong key;
+ size_t key_size;
+ char seed[] = "_ELE_AHAB_SEED_";
+
+ if (argc != 3)
+ return CMD_RET_USAGE;
+
+ key = hextoul(argv[1], NULL);
+ key_size = simple_strtoul(argv[2], NULL, 10);
+ if (key_size != 16 && key_size != 32) {
+ printf("key size can only be 16 or 32\n");
+ return CMD_RET_FAILURE;
+ }
+
+ if (ele_derive_huk((u8 *)key, key_size, seed, sizeof(seed))) {
+ printf("Error in AHAB derive\n");
+ return CMD_RET_FAILURE;
+ }
+
+ return CMD_RET_SUCCESS;
+}
+
static int do_ahab_commit(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
@@ -680,6 +705,12 @@ U_BOOT_CMD(ahab_return_lifecycle, CONFIG_SYS_MAXARGS, 1, do_ahab_return_lifecycl
"addr - Return lifecycle message block signed by OEM SRK\n"
);
+U_BOOT_CMD(ahab_derive, CONFIG_SYS_MAXARGS, 3, do_ahab_derive,
+ "Derive the hardware unique key",
+ "addr [16|32]\n"
+ "Store at addr the derivation of the HUK on 16 or 32 bytes.\n"
+);
+
U_BOOT_CMD(ahab_commit, CONFIG_SYS_MAXARGS, 1, do_ahab_commit,
"commit into the fuses any new SRK revocation and FW version information\n"
"that have been found into the NXP (ELE FW) and OEM containers",
diff --git a/drivers/misc/imx_ele/ele_api.c b/drivers/misc/imx_ele/ele_api.c
index 3745504637b..b753419f01b 100644
--- a/drivers/misc/imx_ele/ele_api.c
+++ b/drivers/misc/imx_ele/ele_api.c
@@ -1,11 +1,13 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2020, 2023 NXP
+ * Copyright 2024 Mathieu Othacehe <othacehe at gnu.org>
*
*/
#include <hang.h>
#include <malloc.h>
+#include <memalign.h>
#include <asm/io.h>
#include <dm.h>
#include <asm/mach-imx/ele_api.h>
@@ -527,6 +529,81 @@ int ele_start_rng(void)
return ret;
}
+int ele_derive_huk(u8 *key, size_t key_size, u8 *seed, size_t seed_size)
+{
+ struct udevice *dev = gd->arch.ele_dev;
+ struct ele_msg msg;
+ int msg_size = sizeof(struct ele_msg);
+ u8 *seed_aligned, *key_aligned;
+ int ret, size;
+
+ if (!dev) {
+ printf("ele dev is not initialized\n");
+ return -ENODEV;
+ }
+
+ if (key_size != 16 && key_size != 32) {
+ printf("key size can only be 16 or 32\n");
+ return -EINVAL;
+ }
+
+ if (seed_size >= (1U << 16) - 1) {
+ printf("seed size is too large\n");
+ return -EINVAL;
+ }
+
+ seed_aligned = memalign(ARCH_DMA_MINALIGN, seed_size);
+ if (!seed_aligned) {
+ printf("failed to alloc memory\n");
+ return -EINVAL;
+ }
+ memcpy(seed_aligned, seed, seed_size);
+
+ key_aligned = memalign(ARCH_DMA_MINALIGN, key_size);
+ if (!key_aligned) {
+ printf("failed to alloc memory\n");
+ ret = -EINVAL;
+ goto ret_seed;
+ }
+
+ size = ALIGN(seed_size, ARCH_DMA_MINALIGN);
+ flush_dcache_range((ulong)seed_aligned,
+ (ulong)seed_aligned + size);
+
+ size = ALIGN(key_size, ARCH_DMA_MINALIGN);
+ invalidate_dcache_range((ulong)key_aligned,
+ (ulong)key_aligned + size);
+
+ msg.version = ELE_VERSION;
+ msg.tag = ELE_CMD_TAG;
+ msg.size = 7;
+ msg.command = ELE_CMD_DERIVE_KEY;
+ msg.data[0] = upper_32_bits((ulong)key_aligned);
+ msg.data[1] = lower_32_bits((ulong)key_aligned);
+ msg.data[2] = upper_32_bits((ulong)seed_aligned);
+ msg.data[3] = lower_32_bits((ulong)seed_aligned);
+ msg.data[4] = seed_size << 16 | key_size;
+ msg.data[5] = compute_crc(&msg);
+
+ ret = misc_call(dev, false, &msg, msg_size, &msg, msg_size);
+ if (ret) {
+ printf("Error: %s: ret %d, response 0x%x\n",
+ __func__, ret, msg.data[0]);
+ goto ret_key;
+ }
+
+ invalidate_dcache_range((ulong)key_aligned,
+ (ulong)key_aligned + size);
+ memcpy(key, key_aligned, key_size);
+
+ret_key:
+ free(key_aligned);
+ret_seed:
+ free(seed_aligned);
+
+ return ret;
+}
+
int ele_commit(u16 fuse_id, u32 *response, u32 *info_type)
{
struct udevice *dev = gd->arch.ele_dev;
--
2.45.2
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