imx: ele_ahab: Add HUK derivation support

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>
Reviewed-by: Ye Li <ye.li@nxp.com>
diff --git a/arch/arm/include/asm/mach-imx/ele_api.h b/arch/arm/include/asm/mach-imx/ele_api.h
index a29b849..d4ac567 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_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 c13d9f0e..647daeb 100644
--- a/arch/arm/mach-imx/ele_ahab.c
+++ b/arch/arm/mach-imx/ele_ahab.c
@@ -624,6 +624,31 @@
 	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 @@
 	   "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",