Implement BIS Key derivation.

This commit is contained in:
Michael Scire 2018-03-31 15:36:54 -06:00
parent 19178d6176
commit 2d8812ac6e
4 changed files with 94 additions and 8 deletions

View file

@ -1,6 +1,7 @@
#include "key_derivation.h"
#include "se.h"
#include "exocfg.h"
#include "fuse.h"
static const u8 keyblob_seeds[MASTERKEY_REVISION_MAX][0x10] =
{
@ -82,6 +83,7 @@ void derive_nx_keydata(u32 target_firmware) {
/* Clear the SBK. */
clear_aes_keyslot(0xE);
se_aes_ecb_decrypt_block(0xD, work_buffer, 0x10, keyblob_mac_seed, 0x10);
decrypt_data_into_keyslot(0xB, 0xD, keyblob_mac_seed, 0x10);
/* Validate keyblob. */
@ -107,24 +109,98 @@ void derive_nx_keydata(u32 target_firmware) {
case EXOSPHERE_TARGET_FIRMWARE_300:
decrypt_data_into_keyslot(0xD, 0xF, devicekey_seed, 0x10);
decrypt_data_into_keyslot(0xC, 0xC, masterkey_seed, 0x10);
set_aes_keyslot_flags(0xC, 0xFF);
set_aes_keyslot_flags(0xD, 0xFF);
break;
case EXOSPHERE_TARGET_FIRMWARE_400:
decrypt_data_into_keyslot(0xD, 0xF, devicekey_4x_seed, 0x10);
decrypt_data_into_keyslot(0xF, 0xF, devicekey_seed, 0x10);
decrypt_data_into_keyslot(0xE, 0xC, masterkey_4x_seed, 0x10);
decrypt_data_into_keyslot(0xC, 0xC, masterkey_seed, 0x10);
set_aes_keyslot_flags(0xC, 0xFF);
set_aes_keyslot_flags(0xF, 0xFF);
break;
case EXOSPHERE_TARGET_FIRMWARE_500:
decrypt_data_into_keyslot(0xA, 0xF, devicekey_4x_seed, 0x10);
decrypt_data_into_keyslot(0xF, 0xF, devicekey_seed, 0x10);
decrypt_data_into_keyslot(0xE, 0xC, masterkey_4x_seed, 0x10);
decrypt_data_into_keyslot(0xC, 0xC, masterkey_seed, 0x10);
set_aes_keyslot_flags(0xC, 0xFF);
set_aes_keyslot_flags(0xF, 0xFF);
break;
default:
generic_panic();
}
}
/* Sets final keyslot flags, for handover to TZ/Exosphere. Setting these will prevent the BPMP from using the device key or master key. */
void finalize_nx_keydata(u32 target_firmware) {
set_aes_keyslot_flags(0xC, 0xFF);
set_aes_keyslot_flags((target_firmware >= EXOSPHERE_TARGET_FIRMWARE_400) ? (KEYSLOT_SWITCH_4XOLDDEVICEKEY) : (KEYSLOT_SWITCH_DEVICEKEY), 0xFF);
}
void fusee_generate_specific_aes_key(void *dst, const void *wrapped_key, bool should_mask, u32 target_firmware) {
unsigned int keyslot = (target_firmware >= EXOSPHERE_TARGET_FIRMWARE_400) ? (KEYSLOT_SWITCH_4XOLDDEVICEKEY) : (KEYSLOT_SWITCH_DEVICEKEY);
if (fuse_get_bootrom_patch_version() < 0x7F) {
/* On dev units, use a fixed "all-zeroes" seed. */
/* Yes, this data really is all-zero in actual TrustZone .rodata. */
static const u8 dev_specific_aes_key_source[0x10] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
static const u8 dev_specific_aes_key_ctr[0x10] = {0x3C, 0xD5, 0x92, 0xEC, 0x68, 0x31, 0x4A, 0x06, 0xD4, 0x1B, 0x0C, 0xD9, 0xF6, 0x2E, 0xD9, 0xE9};
static const u8 dev_specific_aes_key_mask[0x10] = {0xAC, 0xCA, 0x9A, 0xCA, 0xFF, 0x2E, 0xB9, 0x22, 0xCC, 0x1F, 0x4F, 0xAD, 0xDD, 0x77, 0x21, 0x1E};
se_aes_ctr_crypt(keyslot, dst, 0x10, dev_specific_aes_key_source, 0x10, dev_specific_aes_key_ctr, 0x10);
if (should_mask) {
for (unsigned int i = 0; i < 0x10; i++) {
((u8 *)dst)[i] ^= dev_specific_aes_key_mask[i];
}
}
} else {
/* On retail, standard kek->key decryption. */
static const u8 retail_specific_aes_key_source[0x10] = {0xE2, 0xD6, 0xB8, 0x7A, 0x11, 0x9C, 0xB8, 0x80, 0xE8, 0x22, 0x88, 0x8A, 0x46, 0xFB, 0xA1, 0x95};
decrypt_data_into_keyslot(KEYSLOT_SWITCH_TEMPKEY, keyslot, retail_specific_aes_key_source, 0x10);
se_aes_ecb_decrypt_block(KEYSLOT_SWITCH_TEMPKEY, dst, 0x10, wrapped_key, 0x10);
}
}
void fusee_generate_personalized_aes_key_for_bis(void *dst, const void *wrapped_kek, const void *wrapped_key, u32 target_firmware) {
static const u8 kek_source[0x10] = {
0x4D, 0x87, 0x09, 0x86, 0xC4, 0x5D, 0x20, 0x72, 0x2F, 0xBA, 0x10, 0x53, 0xDA, 0x92, 0xE8, 0xA9
};
static const u8 key_source[0x10] = {
0x89, 0x61, 0x5E, 0xE0, 0x5C, 0x31, 0xB6, 0x80, 0x5F, 0xE5, 0x8F, 0x3D, 0xA2, 0x4F, 0x7A, 0xA8
};
unsigned int keyslot = (target_firmware >= EXOSPHERE_TARGET_FIRMWARE_400) ? (KEYSLOT_SWITCH_4XOLDDEVICEKEY) : (KEYSLOT_SWITCH_DEVICEKEY);
/* Derive kek. */
decrypt_data_into_keyslot(KEYSLOT_SWITCH_TEMPKEY, keyslot, kek_source, 0x10);
decrypt_data_into_keyslot(KEYSLOT_SWITCH_TEMPKEY, KEYSLOT_SWITCH_TEMPKEY, wrapped_kek, 0x10);
/* Derive key. */
decrypt_data_into_keyslot(KEYSLOT_SWITCH_TEMPKEY, KEYSLOT_SWITCH_TEMPKEY, key_source, 0x10);
se_aes_ecb_decrypt_block(KEYSLOT_SWITCH_TEMPKEY, dst, 0x10, wrapped_key, 0x10);
}
void derive_bis_key(void *dst, BisPartition_t partition_id, u32 target_firmware) {
static const u8 key_source_for_bis[3][2][0x10] = {
{
{0xF8, 0x3F, 0x38, 0x6E, 0x2C, 0xD2, 0xCA, 0x32, 0xA8, 0x9A, 0xB9, 0xAA, 0x29, 0xBF, 0xC7, 0x48},
{0x7D, 0x92, 0xB0, 0x3A, 0xA8, 0xBF, 0xDE, 0xE1, 0xA7, 0x4C, 0x3B, 0x6E, 0x35, 0xCB, 0x71, 0x06}
},
{
{0x41, 0x00, 0x30, 0x49, 0xDD, 0xCC, 0xC0, 0x65, 0x64, 0x7A, 0x7E, 0xB4, 0x1E, 0xED, 0x9C, 0x5F},
{0x44, 0x42, 0x4E, 0xDA, 0xB4, 0x9D, 0xFC, 0xD9, 0x87, 0x77, 0x24, 0x9A, 0xDC, 0x9F, 0x7C, 0xA4}
},
{
{0x52, 0xC2, 0xE9, 0xEB, 0x09, 0xE3, 0xEE, 0x29, 0x32, 0xA1, 0x0C, 0x1F, 0xB6, 0xA0, 0x92, 0x6C},
{0x4D, 0x12, 0xE1, 0x4B, 0x2A, 0x47, 0x4C, 0x1C, 0x09, 0xCB, 0x03, 0x59, 0xF0, 0x15, 0xF4, 0xE4}
}
};
static const u8 bis_kek_source[0x10] = {0x34, 0xC1, 0xA0, 0xC4, 0x82, 0x58, 0xF8, 0xB4, 0xFA, 0x9E, 0x5E, 0x6A, 0xDA, 0xFC, 0x7E, 0x4F};
switch (partition_id) {
case BisPartition_Calibration:
fusee_generate_specific_aes_key(dst, key_source_for_bis[partition_id][0], false, target_firmware);
fusee_generate_specific_aes_key(dst + 0x10, key_source_for_bis[partition_id][1], false, target_firmware);
break;
case BisPartition_User:
case BisPartition_System:
fusee_generate_personalized_aes_key_for_bis(dst, bis_kek_source, key_source_for_bis[partition_id][0], target_firmware);
fusee_generate_personalized_aes_key_for_bis(dst + 0x10, bis_kek_source, key_source_for_bis[partition_id][1], target_firmware);
break;
default:
generic_panic();

View file

@ -14,6 +14,12 @@
#define MASTERKEY_NUM_NEW_DEVICE_KEYS (MASTERKEY_REVISION_MAX - MASTERKEY_REVISION_400_410)
typedef enum {
BisPartition_Calibration = 0,
BisPartition_User = 1,
BisPartition_System = 2
} BisPartition_t;
typedef struct {
u8 mac[0x10];
u8 ctr[0x10];
@ -24,5 +30,8 @@ typedef struct {
} nx_keyblob_t;
void derive_nx_keydata(u32 target_firmware);
void finalize_nx_keydata(u32 target_firmware);
void derive_bis_key(void *dst, BisPartition_t partition_id, u32 target_firmware);
#endif

View file

@ -11,7 +11,7 @@ static unsigned int g_se_modulus_sizes[KEYSLOT_RSA_MAX];
static unsigned int g_se_exp_sizes[KEYSLOT_RSA_MAX];
/* Initialize a SE linked list. */
void ll_init(volatile se_ll_t *ll, void *buffer, size_t size) {
void NOINLINE ll_init(volatile se_ll_t *ll, void *buffer, size_t size) {
ll->num_entries = 0; /* 1 Entry. */
if (buffer != NULL) {
@ -165,7 +165,7 @@ void set_se_ctr(const void *ctr) {
}
void decrypt_data_into_keyslot(unsigned int keyslot_dst, unsigned int keyslot_src, const void *wrapped_key, size_t wrapped_key_size) {
if (keyslot_dst >= KEYSLOT_AES_MAX || keyslot_src >= KEYSIZE_AES_MAX || wrapped_key_size > KEYSIZE_AES_MAX) {
if (keyslot_dst >= KEYSLOT_AES_MAX || keyslot_src >= KEYSLOT_AES_MAX || wrapped_key_size > KEYSIZE_AES_MAX) {
generic_panic();
}

View file

@ -19,6 +19,7 @@
#define PACKED __attribute__((packed))
#define ALINLINE __attribute__((always_inline))
#define NOINLINE __attribute__((noinline))
#define SET_SYSREG(reg, val) do { temp_reg = (val); __asm__ __volatile__ ("msr " #reg ", %0" :: "r"(temp_reg) : "memory"); } while(false)