Atmosphere/fusee/fusee-secondary/src/package2.c

350 lines
14 KiB
C

/*
* Copyright (c) 2018 Atmosphère-NX
*
* 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 <stdio.h>
#include <stdlib.h>
#include "utils.h"
#include "masterkey.h"
#include "stratosphere.h"
#include "package2.h"
#include "kernel_patches.h"
#include "kip.h"
#include "se.h"
#include "fs_utils.h"
#define u8 uint8_t
#define u32 uint32_t
#include "thermosphere_bin.h"
#include "lib/log.h"
#undef u8
#undef u32
static void package2_decrypt(package2_header_t *package2);
static size_t package2_get_src_section(void **section, package2_header_t *package2, unsigned int id);
static size_t package2_get_thermosphere(void **thermosphere);
static ini1_header_t *package2_rebuild_ini1(ini1_header_t *ini1, uint32_t target_firmware);
static void package2_append_section(unsigned int id, package2_header_t *package2, void *data, size_t size);
static void package2_fixup_header_and_section_hashes(package2_header_t *package2, size_t size);
static inline size_t align_to_4(size_t s) {
return ((s + 3) >> 2) << 2;
}
void package2_rebuild_and_copy(package2_header_t *package2, uint32_t target_firmware) {
package2_header_t *rebuilt_package2;
size_t rebuilt_package2_size;
void *kernel;
size_t kernel_size;
bool is_sd_kernel = false;
void *thermosphere;
size_t thermosphere_size;
ini1_header_t *orig_ini1, *rebuilt_ini1;
/* First things first: Decrypt Package2 in place. */
package2_decrypt(package2);
print(SCREEN_LOG_LEVEL_DEBUG, "Decrypted package2!\n");
kernel_size = package2_get_src_section(&kernel, package2, PACKAGE2_SECTION_KERNEL);
/* Modify Package2 to add an additional thermosphere section. */
thermosphere_size = package2_get_thermosphere(&thermosphere);
if (thermosphere_size != 0 && package2->metadata.section_sizes[PACKAGE2_SECTION_UNUSED] != 0) {
fatal_error(u8"Error: Package2 has no unused section for Thermosphère!\n");
}
/* Load Kernel from SD, if possible. */
{
size_t sd_kernel_size = get_file_size("atmosphere/kernel.bin");
if (sd_kernel_size != 0) {
if (sd_kernel_size > PACKAGE2_SIZE_MAX) {
fatal_error("Error: atmosphere/kernel.bin is too large!\n");
}
kernel = malloc(sd_kernel_size);
if (kernel == NULL) {
fatal_error("Error: failed to allocate kernel!\n");
}
if (read_from_file(kernel, sd_kernel_size, "atmosphere/kernel.bin") != sd_kernel_size) {
fatal_error("Error: failed to read atmosphere/kernel.bin!\n");
}
kernel_size = sd_kernel_size;
is_sd_kernel = true;
}
}
/* Perform any patches we want to the NX kernel. */
package2_patch_kernel(kernel, kernel_size, is_sd_kernel);
print(SCREEN_LOG_LEVEL_DEBUG, "Rebuilding the INI1 section...\n");
package2_get_src_section((void *)&orig_ini1, package2, PACKAGE2_SECTION_INI1);
/* Perform any patches to the INI1, rebuilding it (This is where our built-in sysmodules will be added.) */
rebuilt_ini1 = package2_rebuild_ini1(orig_ini1, target_firmware);
print(SCREEN_LOG_LEVEL_DEBUG, "Rebuilt INI1...\n");
/* Allocate the rebuilt package2. */
rebuilt_package2_size = sizeof(package2_header_t) + kernel_size + align_to_4(thermosphere_size) + align_to_4(rebuilt_ini1->size);
if (rebuilt_package2_size > PACKAGE2_SIZE_MAX) {
fatal_error("rebuilt package2 is too big!\n");
}
rebuilt_package2 = (package2_header_t *)malloc(rebuilt_package2_size);
if (rebuilt_package2 == NULL) {
fatal_error("package2_rebuild: out of memory!\n");
}
/* Rebuild package2. */
memcpy(rebuilt_package2, package2, sizeof(package2_header_t));
package2_append_section(PACKAGE2_SECTION_KERNEL, rebuilt_package2, kernel, kernel_size);
package2_append_section(PACKAGE2_SECTION_INI1, rebuilt_package2, rebuilt_ini1, rebuilt_ini1->size);
package2_append_section(PACKAGE2_SECTION_UNUSED, rebuilt_package2, thermosphere, thermosphere_size);
/* Fix all necessary data in the header to accomodate for the new patches. */
package2_fixup_header_and_section_hashes(rebuilt_package2, rebuilt_package2_size);
/* Relocate Package2. */
memcpy(NX_BOOTLOADER_PACKAGE2_LOAD_ADDRESS, rebuilt_package2, rebuilt_package2_size);
/* We're done. */
free(rebuilt_ini1);
free(rebuilt_package2);
}
static void package2_crypt_ctr(unsigned int master_key_rev, void *dst, size_t dst_size, const void *src, size_t src_size, const void *ctr, size_t ctr_size) {
/* Derive package2 key. */
const uint8_t __attribute__((aligned(16))) package2_key_source[0x10] = {
0xFB, 0x8B, 0x6A, 0x9C, 0x79, 0x00, 0xC8, 0x49, 0xEF, 0xD2, 0x4D, 0x85, 0x4D, 0x30, 0xA0, 0xC7
};
unsigned int keyslot = mkey_get_keyslot(master_key_rev);
decrypt_data_into_keyslot(KEYSLOT_SWITCH_PACKAGE2KEY, keyslot, package2_key_source, 0x10);
/* Perform Encryption. */
se_aes_ctr_crypt(KEYSLOT_SWITCH_PACKAGE2KEY, dst, dst_size, src, src_size, ctr, ctr_size);
}
static bool package2_validate_metadata(package2_meta_t *metadata, uint8_t data[]) {
if (metadata->magic != MAGIC_PK21) {
return false;
}
/* Package2 size, version number is stored XORed in header CTR. */
/* Nintendo, what the fuck? */
uint32_t package_size = package2_meta_get_size(metadata);
uint8_t header_version = package2_meta_get_header_version(metadata);
/* Ensure package isn't too big or too small. */
if (package_size <= sizeof(package2_header_t) || package_size > PACKAGE2_SIZE_MAX) {
return false;
}
/* Validate that we're working with a header we know how to handle. */
if (header_version > MASTERKEY_REVISION_MAX) {
return false;
}
/* Require aligned entrypoint. */
if (metadata->entrypoint & 3) {
return false;
}
/* Validate section size sanity. */
if (metadata->section_sizes[0] + metadata->section_sizes[1] + metadata->section_sizes[2] + sizeof(package2_header_t) != package_size) {
return false;
}
bool entrypoint_found = false;
/* Header has space for 4 sections, but only 3 are validated/potentially loaded on hardware. */
size_t cur_section_offset = 0;
for (unsigned int section = 0; section < PACKAGE2_SECTION_MAX; section++) {
/* Validate section size alignment. */
if (metadata->section_sizes[section] & 3) {
return false;
}
/* Validate section does not overflow. */
if (check_32bit_additive_overflow(metadata->section_offsets[section], metadata->section_sizes[section])) {
return false;
}
/* Check for entrypoint presence. */
uint32_t section_end = metadata->section_offsets[section] + metadata->section_sizes[section];
if (metadata->section_offsets[section] <= metadata->entrypoint && metadata->entrypoint < section_end) {
entrypoint_found = true;
}
/* Ensure no overlap with later sections. */
for (unsigned int later_section = section + 1; later_section < PACKAGE2_SECTION_MAX; later_section++) {
uint32_t later_section_end = metadata->section_offsets[later_section] + metadata->section_sizes[later_section];
if (overlaps(metadata->section_offsets[section], section_end, metadata->section_offsets[later_section], later_section_end)) {
return false;
}
}
/* Validate section hashes. */
if (metadata->section_sizes[section]) {
void *section_data = data + cur_section_offset;
uint8_t calculated_hash[0x20];
se_calculate_sha256(calculated_hash, section_data, metadata->section_sizes[section]);
if (memcmp(calculated_hash, metadata->section_hashes[section], sizeof(metadata->section_hashes[section])) != 0) {
return false;
}
cur_section_offset += metadata->section_sizes[section];
}
}
/* Ensure that entrypoint is present in one of our sections. */
if (!entrypoint_found) {
return false;
}
/* Perform version checks. */
/* We will be compatible with all package2s released before current, but not newer ones. */
if (metadata->version_max >= PACKAGE2_MINVER_THEORETICAL && metadata->version_min < PACKAGE2_MAXVER_620_CURRENT) {
return true;
}
return false;
}
static uint32_t package2_decrypt_and_validate_header(package2_header_t *header, bool is_plaintext) {
package2_meta_t metadata;
/* TODO: Also accept plaintext package2 based on bootconfig. */
if (!is_plaintext) {
uint32_t mkey_rev;
/* Try to decrypt for all possible master keys. */
for (mkey_rev = 0; mkey_rev <= mkey_get_revision(); mkey_rev++) {
package2_crypt_ctr(mkey_rev, &metadata, sizeof(package2_meta_t), &header->metadata, sizeof(package2_meta_t), header->metadata.ctr, sizeof(header->metadata.ctr));
/* Copy the ctr (which stores information) into the decrypted metadata. */
memcpy(metadata.ctr, header->metadata.ctr, sizeof(header->metadata.ctr));
/* See if this is the correct key. */
if (package2_validate_metadata(&metadata, header->data)) {
header->metadata = metadata;
return mkey_rev;
}
}
/* Ensure we successfully decrypted the header. */
if (mkey_rev > mkey_get_revision()) {
fatal_error("Failed to decrypt the Package2 header (master key revision %u)!\n", mkey_get_revision());
}
} else if (!package2_validate_metadata(&header->metadata, header->data)) {
fatal_error("Failed to validate the Package2 header!\n");
}
return 0;
}
static void package2_decrypt(package2_header_t *package2) {
bool is_package2_plaintext = package2->signature[0];
is_package2_plaintext &= memcmp(package2->signature, package2->signature + 1, sizeof(package2->signature) - 1) == 0;
is_package2_plaintext &= package2->metadata.magic == MAGIC_PK21;
uint32_t pk21_mkey_revision = package2_decrypt_and_validate_header(package2, is_package2_plaintext);
size_t cur_section_offset = 0;
/* Copy each section to its appropriate location, decrypting if necessary. */
for (unsigned int section = 0; section < PACKAGE2_SECTION_MAX; section++) {
if (package2->metadata.section_sizes[section] == 0) {
continue;
}
void *src_start = package2->data + cur_section_offset;
void *dst_start = src_start;
size_t size = (size_t)package2->metadata.section_sizes[section];
if (is_package2_plaintext&& size != 0) {
memcpy(dst_start, src_start, size);
} else if (size != 0) {
package2_crypt_ctr(pk21_mkey_revision, dst_start, size, src_start, size, package2->metadata.section_ctrs[section], 0x10);
}
cur_section_offset += size;
}
/* Clear the signature, to signal that this is a plaintext, unsigned package2. */
memset(package2->signature, 0, sizeof(package2->signature));
}
static size_t package2_get_src_section(void **section, package2_header_t *package2, unsigned int id) {
uint8_t *data = package2->data;
for (unsigned int i = 0; i < id; i++) {
data += package2->metadata.section_sizes[i];
}
(*section) = data;
return package2->metadata.section_sizes[id];
}
static size_t package2_get_thermosphere(void **thermosphere) {
/*extern const uint8_t thermosphere_bin[];
extern const uint32_t thermosphere_bin_size;*/
/* TODO: enable when tested. */
(*thermosphere) = NULL;
return 0;
}
static ini1_header_t *package2_rebuild_ini1(ini1_header_t *ini1, uint32_t target_firmware) {
/* TODO: Do we want to support loading another INI from sd:/whatever/INI1.bin? */
ini1_header_t *inis_to_merge[STRATOSPHERE_INI1_MAX] = {0};
ini1_header_t *merged;
inis_to_merge[STRATOSPHERE_INI1_SDFILES] = stratosphere_get_sd_files_ini1();
inis_to_merge[STRATOSPHERE_INI1_EMBEDDED] = stratosphere_get_ini1(target_firmware);
inis_to_merge[STRATOSPHERE_INI1_PACKAGE2] = ini1;
/* Merge all of the INI1s. */
merged = stratosphere_merge_inis(inis_to_merge, STRATOSPHERE_INI1_MAX);
/* Free temporary buffer. */
stratosphere_free_ini1();
return merged;
}
static void package2_append_section(unsigned int id, package2_header_t *package2, void *data, size_t size) {
/* This function must be called in ascending order of id. */
/* We assume that the loading address doesn't need to be changed. */
uint8_t *dst = package2->data;
for (unsigned int i = 0; i < id; i++) {
dst += package2->metadata.section_sizes[i];
}
memcpy(dst, data, size);
package2->metadata.section_sizes[id] = align_to_4(size);
}
static void package2_fixup_header_and_section_hashes(package2_header_t *package2, size_t size) {
uint8_t *data = package2->data;
for (unsigned int section = 0; section < PACKAGE2_SECTION_MAX; section++) {
size_t sz = (size_t)package2->metadata.section_sizes[section];
if (sz == 0) {
continue;
}
/* Fix up the hash. */
se_calculate_sha256(package2->metadata.section_hashes[section], data, sz);
data += sz;
}
/* Fix up the size in XOR'd CTR. */
uint32_t package_size = package2->metadata.ctr_dwords[0] ^ package2->metadata.ctr_dwords[2] ^ package2->metadata.ctr_dwords[3];
package2->metadata.ctr_dwords[3] ^= (package_size ^ size);
}