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@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@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;