Implement masterkey logic, KEYSLOT defines.

This commit is contained in:
Michael Scire 2018-02-19 23:41:27 -08:00
parent 61f8886879
commit 07f9e9500e
5 changed files with 126 additions and 7 deletions

90
exosphere/masterkey.c Normal file
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@ -0,0 +1,90 @@
#include <stdint.h>
#include "utils.h"
#include "masterkey.h"
#include "se.h"
unsigned int g_mkey_revision = 0;
int g_determined_mkey_revision = 0;
uint8_t g_old_masterkeys[MASTERKEY_REVISION_MAX][0x10];
/* TODO: Dev keys. */
/* TODO: Extend with new vectors, as needed. */
const uint8_t mkey_vectors[MASTERKEY_REVISION_MAX][0x10] =
{
{0x0C, 0xF0, 0x59, 0xAC, 0x85, 0xF6, 0x26, 0x65, 0xE1, 0xE9, 0x19, 0x55, 0xE6, 0xF2, 0x67, 0x3D}, /* Zeroes encrypted with Master Key 00. */
{0x29, 0x4C, 0x04, 0xC8, 0xEB, 0x10, 0xED, 0x9D, 0x51, 0x64, 0x97, 0xFB, 0xF3, 0x4D, 0x50, 0xDD}, /* Master key 00 encrypted with Master key 01. */
{0xDE, 0xCF, 0xEB, 0xEB, 0x10, 0xAE, 0x74, 0xD8, 0xAD, 0x7C, 0xF4, 0x9E, 0x62, 0xE0, 0xE8, 0x72}, /* Master key 01 encrypted with Master key 02. */
{0x0A, 0x0D, 0xDF, 0x34, 0x22, 0x06, 0x6C, 0xA4, 0xE6, 0xB1, 0xEC, 0x71, 0x85, 0xCA, 0x4E, 0x07}, /* Master key 02 encrypted with Master key 03. */
}
int check_mkey_revision(unsigned int revision) {
uint8_t final_vector[0x10];
unsigned int check_keyslot = KEYSLOT_SWITCH_MASTERKEY;
if (revision > 0) {
/* Generate old master key array. */
for (unsigned int i = revision; i > 0; i--) {
se_aes_ecb_decrypt_block(check_keyslot, g_old_masterkeys[i-1], 0x10, mkey_vectors[i], 0x10);
set_aes_keyslot(KEYSLOT_SWITCH_TEMPKEY, g_old_masterkeys[i-1], 0x10);
check_keyslot = KEYSLOT_SWITCH_TEMPKEY;
}
}
se_aes_ecb_decrypt_block(check_keyslot, final_vector, 0x10, mkey_vectors[0], 0x10);
for (unsigned int i = 0; i < 0x10; i++) {
if (final_vector[i] != 0) {
return 0;
}
}
return 1;
}
void mkey_detect_revision(void) {
if (g_determined_mkey_revision == 1) {
panic();
}
for (unsigned int rev = 0; rev < MASTERKEY_REVISION_MAX; rev++) {
if (check_mkey_revision(rev)) {
g_determined_mkey_revision = 1;
g_mkey_revision = rev;
break;
}
}
/* We must have determined the master key, or we're not running on a Switch. */
/* TODO: When panic is implemented, make this a really distinctive color. */
/* Maybe bright red? */
if (g_determined_mkey_revision == 0) {
panic();
}
}
unsigned int mkey_get_revision(void) {
if (g_determined_mkey_revision == 0) {
panic();
}
return g_mkey_revision;
}
unsigned int mkey_get_keyslot(unsigned int revision) {
if (g_determined_mkey_revision == 0 || revision >= MASTERKEY_REVISION_MAX) {
panic();
}
if (revision > g_mkey_revision) {
panic();
}
if (revision == g_mkey_revision) {
return KEYSLOT_SWITCH_MASTERKEY;
} else {
/* Load into a temp keyslot. */
set_aes_keyslot(KEYSLOT_SWITCH_TEMPKEY, g_old_masterkeys[revision], 0x10);
return KEYSLOT_SWITCH_TEMPKEY;
}
}

16
exosphere/masterkey.h Normal file
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@ -0,0 +1,16 @@
#ifndef EXOSPHERE_MASTERKEY_H
#define EXOSPHERE_MASTERKEY_H
/* This is glue code to enable master key support across versions. */
/* TODO: Update to 0x5 on release of new master key. */
#define MASTERKEY_REVISION_MAX 0x4
/* This should be called early on in initialization. */
void mkey_detect_revision(void);
unsigned int mkey_get_revision(void);
unsigned int mkey_get_keyslot(unsigned int revision);
#endif

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@ -6,6 +6,15 @@
/* Exosphere driver for the Tegra X1 security engine. */ /* Exosphere driver for the Tegra X1 security engine. */
#define KEYSLOT_SWITCH_TEMPKEY 0x9
#define KEYSLOT_SWITCH_SESSIONKEY 0xA
#define KEYSLOT_SWITCH_RNGKEY 0xB
#define KEYSLOT_SWITCH_MASTERKEY 0xC
#define KEYSLOT_SWITCH_DEVICEKEY 0xD
/* This key was added in 4.0.0. */
#define KEYSLOT_SWITCH_NEWDEVICEKEY 0xF
#define KEYSLOT_AES_MAX 0x10 #define KEYSLOT_AES_MAX 0x10
#define KEYSLOT_RSA_MAX 0x2 #define KEYSLOT_RSA_MAX 0x2

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@ -108,8 +108,7 @@ uint64_t try_set_smc_callback(uint32_t (*callback)(void *, uint64_t)) {
return 0; return 0;
} }
/* TODO: Keyslot defines. */ se_generate_random(KEYSLOT_SWITCH_RNGKEY, &key, sizeof(uint64_t));
se_generate_random(0xB, &key, sizeof(uint64_t));
g_smc_callback_key = key; g_smc_callback_key = key;
g_smc_callback = callback; g_smc_callback = callback;
return key; return key;

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@ -2,6 +2,7 @@
#include "utils.h" #include "utils.h"
#include "cache.h" #include "cache.h"
#include "masterkey.h"
#include "smc_api.h" #include "smc_api.h"
#include "smc_user.h" #include "smc_user.h"
#include "se.h" #include "se.h"
@ -88,10 +89,10 @@ uint32_t user_load_aes_key(smc_args_t *args) {
wrapped_key[1] = args->X[5]; wrapped_key[1] = args->X[5];
/* TODO: Unseal the kek. */ /* TODO: Unseal the kek. */
set_aes_keyslot(9, sealed_kek, 0x10); set_aes_keyslot(KEYSLOT_SWITCH_TEMPKEY, sealed_kek, 0x10);
/* Unwrap the key. */ /* Unwrap the key. */
decrypt_data_into_keyslot(keyslot, 9, wrapped_key, 0x10); decrypt_data_into_keyslot(keyslot, KEYSLOT_SWITCH_TEMPKEY, wrapped_key, 0x10);
return 0; return 0;
} }
@ -221,7 +222,9 @@ uint32_t user_unwrap_rsa_wrapped_titlekey(smc_args_t *args) {
void *user_modulus = (void *)args->X[2]; void *user_modulus = (void *)args->X[2];
unsigned int master_key_rev = (unsigned int)args->X[7]; unsigned int master_key_rev = (unsigned int)args->X[7];
/* TODO: Validate Master Key Revision. */ if (master_key_rev >= MASTERKEY_REVISION_MAX) {
return 2;
}
/* Copy user data into secure memory. */ /* Copy user data into secure memory. */
if (upage_init(&page_ref, user_wrapped_key) == 0) { if (upage_init(&page_ref, user_wrapped_key) == 0) {
@ -277,7 +280,10 @@ uint32_t user_unwrap_aes_wrapped_titlekey(smc_args_t *args) {
unsigned int master_key_rev = (unsigned int)args->X[3]; unsigned int master_key_rev = (unsigned int)args->X[3];
/* TODO: Validate Master Key Revision. */ if (master_key_rev >= MASTERKEY_REVISION_MAX) {
return 2;
}
tkey_set_master_key_rev(master_key_rev); tkey_set_master_key_rev(master_key_rev);
@ -286,5 +292,4 @@ uint32_t user_unwrap_aes_wrapped_titlekey(smc_args_t *args) {
args->X[1] = sealed_titlekey[0]; args->X[1] = sealed_titlekey[0];
args->X[2] = sealed_titlekey[1]; args->X[2] = sealed_titlekey[1];
} }