Lockpick_RCM/source/keys/ssl_crypto.c

121 lines
4.1 KiB
C

/*
* Copyright (c) 2022 shchmue
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "ssl_crypto.h"
#include "cal0_read.h"
#include "gmac.h"
#include "../config.h"
#include <gfx_utils.h>
#include <sec/se.h>
#include <sec/se_t210.h>
#include <string.h>
extern hekate_config h_cfg;
void ssl_derive_rsa_kek_device_unique(key_storage_t *keys, void *out_rsa_kek, u32 generation) {
if ((!h_cfg.t210b01 && !key_exists(keys->device_key)) || (h_cfg.t210b01 && (!key_exists(keys->master_key[0]) || !key_exists(keys->device_key_4x)))) {
return;
}
const u32 option = SET_SEAL_KEY_INDEX(SEAL_KEY_IMPORT_SSL_KEY) | IS_DEVICE_UNIQUE;
derive_rsa_kek(KS_AES_ECB, keys, out_rsa_kek, ssl_client_cert_kek_source, ssl_client_cert_key_source, generation, option);
}
void ssl_derive_rsa_kek_legacy(key_storage_t *keys, void *out_rsa_kek) {
if (!key_exists(keys->master_key[0])) {
return;
}
const u32 generation = 0;
const u32 option = SET_SEAL_KEY_INDEX(SEAL_KEY_DECRYPT_DEVICE_UNIQUE_DATA) | NOT_DEVICE_UNIQUE;
derive_rsa_kek(KS_AES_ECB, keys, out_rsa_kek, ssl_rsa_kekek_source, ssl_rsa_kek_source_legacy, generation, option);
}
void ssl_derive_rsa_kek_original(key_storage_t *keys, void *out_rsa_kek, bool is_dev) {
if (!key_exists(keys->master_key[0])) {
return;
}
const void *ssl_kek_source = is_dev ? ssl_rsa_kek_source_dev : ssl_rsa_kek_source;
const u32 generation = 0;
u32 option = SET_SEAL_KEY_INDEX(SEAL_KEY_DECRYPT_DEVICE_UNIQUE_DATA) | NOT_DEVICE_UNIQUE;
derive_rsa_kek(KS_AES_ECB, keys, out_rsa_kek, ssl_rsa_kekek_source, ssl_kek_source, generation, option);
}
bool decrypt_ssl_rsa_key(key_storage_t *keys, void *buffer) {
if (!cal0_read(KS_BIS_00_TWEAK, KS_BIS_00_CRYPT, buffer)) {
return false;
}
nx_emmc_cal0_t *cal0 = (nx_emmc_cal0_t *)buffer;
u32 generation = 0;
const void *encrypted_key = NULL;
const void *iv = NULL;
u32 key_size = 0;
void *ctr_key = NULL;
bool enforce_unique = true;
if (!cal0_get_ssl_rsa_key(cal0, &encrypted_key, &key_size, &iv, &generation)) {
return false;
}
if (key_size == SSL_RSA_KEY_SIZE) {
bool all_zero = true;
const u8 *key8 = (const u8 *)encrypted_key;
for (u32 i = SE_RSA2048_DIGEST_SIZE; i < SSL_RSA_KEY_SIZE; i++) {
if (key8[i] != 0) {
all_zero = false;
break;
}
}
if (all_zero) {
// Keys of this form are not encrypted
memcpy(keys->ssl_rsa_key, encrypted_key, SE_RSA2048_DIGEST_SIZE);
return true;
}
ssl_derive_rsa_kek_legacy(keys, keys->ssl_rsa_kek_legacy);
ctr_key = keys->ssl_rsa_kek_legacy;
enforce_unique = false;
} else if (generation) {
ssl_derive_rsa_kek_device_unique(keys, keys->ssl_rsa_kek_personalized, generation);
ctr_key = keys->ssl_rsa_kek_personalized;
} else {
ctr_key = keys->ssl_rsa_kek;
}
u32 ctr_size = enforce_unique ? key_size - 0x20 : key_size - 0x10;
se_aes_key_set(KS_AES_CTR, ctr_key, SE_KEY_128_SIZE);
se_aes_crypt_ctr(KS_AES_CTR, keys->ssl_rsa_key, ctr_size, encrypted_key, ctr_size, iv);
if (enforce_unique) {
u32 calc_mac[SE_KEY_128_SIZE / 4] = {0};
calc_gmac(KS_AES_ECB, calc_mac, keys->ssl_rsa_key, ctr_size, ctr_key, iv);
const u8 *key8 = (const u8 *)encrypted_key;
if (memcmp(calc_mac, &key8[ctr_size], 0x10) != 0) {
EPRINTF("SSL keypair has invalid GMac.");
memset(keys->ssl_rsa_key, 0, sizeof(keys->ssl_rsa_key));
return false;
}
}
return true;
}