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nxdumptool/source/nca.c
Pablo Curiel c6eaf3c8b6 PFS0 mod data + RomFS start.
2020-04-26 04:35:01 -04:00

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36 KiB
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/*
* Copyright (c) 2020 DarkMatterCore
*
* 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 <string.h>
#include <stdlib.h>
#include "nca.h"
#include "keys.h"
#include "rsa.h"
#include "gamecard.h"
#include "utils.h"
#define NCA_CRYPTO_BUFFER_SIZE 0x800000 /* 8 MiB */
/* Global variables. */
static u8 *g_ncaCryptoBuffer = NULL;
static Mutex g_ncaCryptoBufferMutex = 0;
static const u8 g_nca0KeyAreaHash[SHA256_HASH_SIZE] = {
0x9A, 0xBB, 0xD2, 0x11, 0x86, 0x00, 0x21, 0x9D, 0x7A, 0xDC, 0x5B, 0x43, 0x95, 0xF8, 0x4E, 0xFD,
0xFF, 0x6B, 0x25, 0xEF, 0x9F, 0x96, 0x85, 0x28, 0x18, 0x9E, 0x76, 0xB0, 0x92, 0xF0, 0x6A, 0xCB
};
/* Function prototypes. */
static size_t aes128XtsNintendoCrypt(Aes128XtsContext *ctx, void *dst, const void *src, size_t size, u64 sector, size_t sector_size, bool encrypt); /* Not used anywhere else */
static bool ncaDecryptHeader(NcaContext *ctx);
static bool ncaDecryptKeyArea(NcaContext *ctx);
NX_INLINE bool ncaCheckIfVersion0KeyAreaIsEncrypted(NcaContext *ctx);
NX_INLINE u8 ncaGetKeyGenerationValue(NcaContext *ctx);
NX_INLINE bool ncaCheckRightsIdAvailability(NcaContext *ctx);
NX_INLINE void ncaInitializeAesCtrIv(u8 *out, const u8 *ctr, u64 offset);
NX_INLINE void ncaUpdateAesCtrIv(u8 *ctr, u64 offset);
NX_INLINE void ncaUpdateAesCtrExIv(u8 *ctr, u32 ctr_val, u64 offset);
static bool _ncaReadFsSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset, bool lock);
bool ncaAllocateCryptoBuffer(void)
{
mutexLock(&g_ncaCryptoBufferMutex);
if (!g_ncaCryptoBuffer) g_ncaCryptoBuffer = malloc(NCA_CRYPTO_BUFFER_SIZE);
bool ret = (g_ncaCryptoBuffer != NULL);
mutexUnlock(&g_ncaCryptoBufferMutex);
return ret;
}
void ncaFreeCryptoBuffer(void)
{
mutexLock(&g_ncaCryptoBufferMutex);
if (g_ncaCryptoBuffer)
{
free(g_ncaCryptoBuffer);
g_ncaCryptoBuffer = NULL;
}
mutexUnlock(&g_ncaCryptoBufferMutex);
}
bool ncaEncryptKeyArea(NcaContext *ctx)
{
if (!ctx)
{
LOGFILE("Invalid NCA context!");
return false;
}
u8 key_count;
const u8 *kaek = NULL;
Aes128Context key_area_ctx = {0};
/* Check if we're dealing with a NCA0 with a plain text key area */
if (ctx->format_version == NcaVersion_Nca0 && !ncaCheckIfVersion0KeyAreaIsEncrypted(ctx))
{
memcpy(ctx->header.encrypted_keys, ctx->decrypted_keys, 0x40);
return true;
}
kaek = keysGetKeyAreaEncryptionKey(ctx->key_generation, ctx->header.kaek_index);
if (!kaek)
{
LOGFILE("Unable to retrieve KAEK for key generation 0x%02X and KAEK index 0x%02X!", ctx->key_generation, ctx->header.kaek_index);
return false;
}
key_count = (ctx->format_version == NcaVersion_Nca0 ? 2 : 4);
aes128ContextCreate(&key_area_ctx, kaek, true);
for(u8 i = 0; i < key_count; i++) aes128EncryptBlock(&key_area_ctx, ctx->header.encrypted_keys[i].key, ctx->decrypted_keys[i].key);
return true;
}
bool ncaEncryptHeader(NcaContext *ctx)
{
if (!ctx || !strlen(ctx->content_id_str))
{
LOGFILE("Invalid NCA context!");
return false;
}
u32 i;
size_t crypt_res = 0;
u64 fs_header_offset = 0;
const u8 *header_key = NULL;
Aes128XtsContext hdr_aes_ctx = {0}, nca0_fs_header_ctx = {0};
header_key = keysGetNcaHeaderKey();
aes128XtsContextCreate(&hdr_aes_ctx, header_key, header_key + 0x10, true);
crypt_res = aes128XtsNintendoCrypt(&hdr_aes_ctx, &(ctx->header), &(ctx->header), NCA_HEADER_LENGTH, 0, NCA_AES_XTS_SECTOR_SIZE, true);
if (crypt_res != NCA_HEADER_LENGTH)
{
LOGFILE("Error encrypting partial NCA \"%s\" header!", ctx->content_id_str);
return false;
}
switch(ctx->format_version)
{
case NcaVersion_Nca3:
crypt_res = aes128XtsNintendoCrypt(&hdr_aes_ctx, ctx->header.fs_headers, ctx->header.fs_headers, NCA_FULL_HEADER_LENGTH - NCA_HEADER_LENGTH, 2, NCA_AES_XTS_SECTOR_SIZE, true);
if (crypt_res != NCA_FULL_HEADER_LENGTH)
{
LOGFILE("Error encrypting NCA3 \"%s\" FS section headers!", ctx->content_id_str);
return false;
}
break;
case NcaVersion_Nca2:
for(i = 0; i < NCA_FS_HEADER_COUNT; i++)
{
if (!ctx->header.fs_entries[i].enable_entry) continue;
crypt_res = aes128XtsNintendoCrypt(&hdr_aes_ctx, &(ctx->header.fs_headers[i]), &(ctx->header.fs_headers[i]), NCA_FS_HEADER_LENGTH, 0, NCA_AES_XTS_SECTOR_SIZE, true);
if (crypt_res != NCA_FS_HEADER_LENGTH)
{
LOGFILE("Error encrypting NCA2 \"%s\" FS section header #%u!", ctx->content_id_str, i);
return false;
}
}
break;
case NcaVersion_Nca0:
/* NCA0 FS section headers will be encrypted in-place, but they need to be written to their proper offsets */
aes128XtsContextCreate(&nca0_fs_header_ctx, ctx->decrypted_keys[0].key, ctx->decrypted_keys[1].key, true);
for(i = 0; i < NCA_FS_HEADER_COUNT; i++)
{
if (!ctx->header.fs_entries[i].enable_entry) continue;
fs_header_offset = NCA_FS_ENTRY_BLOCK_OFFSET(ctx->header.fs_entries[i].start_block_offset);
crypt_res = aes128XtsNintendoCrypt(&nca0_fs_header_ctx, &(ctx->header.fs_headers[i]), &(ctx->header.fs_headers[i]), NCA_FS_HEADER_LENGTH, \
NCA_NCA0_FS_HEADER_AES_XTS_SECTOR(fs_header_offset), NCA_AES_XTS_SECTOR_SIZE, true);
if (crypt_res != NCA_FS_HEADER_LENGTH)
{
LOGFILE("Error decrypting NCA0 \"%s\" FS section header #%u!", ctx->content_id_str, i);
return false;
}
}
break;
default:
LOGFILE("Invalid NCA \"%s\" format version! (0x%02X)", ctx->content_id_str, ctx->format_version);
return false;
}
return true;
}
bool ncaInitializeContext(NcaContext *out, u8 storage_id, NcmContentStorage *ncm_storage, u8 hfs_partition_type, const NcmPackagedContentInfo *content_info, Ticket *tik)
{
if (!out || !tik || (storage_id != NcmStorageId_GameCard && !ncm_storage) || (storage_id == NcmStorageId_GameCard && hfs_partition_type > GameCardHashFileSystemPartitionType_Secure) || \
!content_info || content_info->info.content_type > NcmContentType_DeltaFragment)
{
LOGFILE("Invalid parameters!");
return false;
}
/* Fill NCA context */
out->storage_id = storage_id;
out->ncm_storage = (out->storage_id != NcmStorageId_GameCard ? ncm_storage : NULL);
memcpy(&(out->content_id), &(content_info->info.content_id), sizeof(NcmContentId));
utilsGenerateHexStringFromData(out->content_id_str, sizeof(out->content_id_str), out->content_id.c, sizeof(out->content_id.c));
memcpy(out->hash, content_info->hash, SHA256_HASH_SIZE);
utilsGenerateHexStringFromData(out->hash_str, sizeof(out->hash_str), out->hash, sizeof(out->hash));
out->content_type = content_info->info.content_type;
out->id_offset = content_info->info.id_offset;
ncaConvertNcmContentSizeToU64(content_info->info.size, &(out->content_size));
if (out->content_size < NCA_FULL_HEADER_LENGTH)
{
LOGFILE("Invalid size for NCA \"%s\"!", out->content_id_str);
return false;
}
out->rights_id_available = out->dirty_header = false;
if (out->storage_id == NcmStorageId_GameCard)
{
/* Retrieve gamecard NCA offset */
char nca_filename[0x30] = {0};
sprintf(nca_filename, "%s.%s", out->content_id_str, out->content_type == NcmContentType_Meta ? "cnmt.nca" : "nca");
if (!gamecardGetEntryInfoFromHashFileSystemPartitionByName(hfs_partition_type, nca_filename, &(out->gamecard_offset), NULL))
{
LOGFILE("Error retrieving offset for \"%s\" entry in secure hash FS partition!", nca_filename);
return false;
}
}
/* Read NCA header */
if (!ncaReadContentFile(out, &(out->header), sizeof(NcaHeader), 0))
{
LOGFILE("Failed to read NCA \"%s\" header!", out->content_id_str);
return false;
}
/* Decrypt NCA header */
if (!ncaDecryptHeader(out))
{
LOGFILE("Failed to decrypt NCA \"%s\" header!", out->content_id_str);
return false;
}
if (out->header.content_size != out->content_size)
{
LOGFILE("Content size mismatch for NCA \"%s\"! (0x%lX != 0x%lX)", out->content_id_str, out->header.content_size, out->content_size);
return false;
}
/* Fill additional NCA context info */
out->key_generation = ncaGetKeyGenerationValue(out);
out->rights_id_available = ncaCheckRightsIdAvailability(out);
if (out->rights_id_available)
{
/* Retrieve ticket */
/* This will return true if it has already been retrieved */
if (!tikRetrieveTicketByRightsId(tik, &(out->header.rights_id), out->storage_id == NcmStorageId_GameCard))
{
LOGFILE("Error retrieving ticket for NCA \"%s\"!", out->content_id_str);
return false;
}
/* Copy decrypted titlekey */
memcpy(out->titlekey, tik->dec_titlekey, 0x10);
} else {
/* Decrypt key area */
if (out->format_version != NcaVersion_Nca0 && !ncaDecryptKeyArea(out))
{
LOGFILE("Error decrypting NCA key area!");
return false;
}
}
/* Parse sections */
for(u8 i = 0; i < NCA_FS_HEADER_COUNT; i++)
{
if (!out->header.fs_entries[i].enable_entry) continue;
/* Fill section context */
out->fs_contexts[i].nca_ctx = out;
out->fs_contexts[i].section_num = i;
out->fs_contexts[i].section_offset = NCA_FS_ENTRY_BLOCK_OFFSET(out->header.fs_entries[i].start_block_offset);
out->fs_contexts[i].section_size = (NCA_FS_ENTRY_BLOCK_OFFSET(out->header.fs_entries[i].end_block_offset) - out->fs_contexts[i].section_offset);
out->fs_contexts[i].section_type = NcaFsSectionType_Invalid; /* Placeholder */
out->fs_contexts[i].header = &(out->header.fs_headers[i]);
memset(out->fs_contexts[i].ctr, 0, sizeof(out->fs_contexts[i].ctr));
memset(&(out->fs_contexts[i].ctr_ctx), 0, sizeof(Aes128CtrContext));
memset(&(out->fs_contexts[i].xts_decrypt_ctx), 0, sizeof(Aes128XtsContext));
memset(&(out->fs_contexts[i].xts_encrypt_ctx), 0, sizeof(Aes128XtsContext));
/* Determine encryption type */
out->fs_contexts[i].encryption_type = (out->format_version == NcaVersion_Nca0 ? NcaEncryptionType_Nca0 : out->header.fs_headers[i].encryption_type);
if (out->fs_contexts[i].encryption_type == NcaEncryptionType_Auto)
{
switch(out->fs_contexts[i].section_num)
{
case 0: /* ExeFS Partition FS */
case 1: /* RomFS */
out->fs_contexts[i].encryption_type = NcaEncryptionType_AesCtr;
break;
case 2: /* Logo Partition FS */
out->fs_contexts[i].encryption_type = NcaEncryptionType_None;
break;
default:
break;
}
}
/* Check if we're dealing with an invalid encryption type value */
if (out->fs_contexts[i].encryption_type == NcaEncryptionType_Auto || out->fs_contexts[i].encryption_type > NcaEncryptionType_Nca0) continue;
/* Determine FS section type */
if (out->fs_contexts[i].header->fs_type == NcaFsType_PartitionFs && out->fs_contexts[i].header->hash_type == NcaHashType_HierarchicalSha256)
{
out->fs_contexts[i].section_type = NcaFsSectionType_PartitionFs;
} else
if (out->fs_contexts[i].header->fs_type == NcaFsType_RomFs && out->fs_contexts[i].header->hash_type == NcaHashType_HierarchicalIntegrity)
{
out->fs_contexts[i].section_type = (out->fs_contexts[i].encryption_type == NcaEncryptionType_AesCtrEx ? NcaFsSectionType_PatchRomFs : NcaFsSectionType_RomFs);
} else
if (out->fs_contexts[i].header->fs_type == NcaFsType_RomFs && out->fs_contexts[i].header->hash_type == NcaHashType_HierarchicalSha256 && out->format_version == NcaVersion_Nca0)
{
out->fs_contexts[i].section_type = NcaFsSectionType_Nca0RomFs;
}
/* Check if we're dealing with an invalid section type value */
if (out->fs_contexts[i].section_type >= NcaFsSectionType_Invalid) continue;
/* Initialize crypto related fields */
if (out->fs_contexts[i].encryption_type > NcaEncryptionType_None && out->fs_contexts[i].encryption_type <= NcaEncryptionType_Nca0)
{
/* Initialize section CTR */
ncaInitializeAesCtrIv(out->fs_contexts[i].ctr, out->fs_contexts[i].header->section_ctr, out->fs_contexts[i].section_offset);
/* Initialize AES context */
if (out->rights_id_available)
{
aes128CtrContextCreate(&(out->fs_contexts[i].ctr_ctx), out->titlekey, out->fs_contexts[i].ctr);
} else {
if (out->fs_contexts[i].encryption_type == NcaEncryptionType_AesCtr || out->fs_contexts[i].encryption_type == NcaEncryptionType_AesCtrEx)
{
aes128CtrContextCreate(&(out->fs_contexts[i].ctr_ctx), out->decrypted_keys[2].key, out->fs_contexts[i].ctr);
} else
if (out->fs_contexts[i].encryption_type == NcaEncryptionType_AesXts || out->fs_contexts[i].encryption_type == NcaEncryptionType_Nca0)
{
/* We need to create two different contexts: one for decryption and another one for encryption */
aes128XtsContextCreate(&(out->fs_contexts[i].xts_decrypt_ctx), out->decrypted_keys[0].key, out->decrypted_keys[1].key, false);
aes128XtsContextCreate(&(out->fs_contexts[i].xts_encrypt_ctx), out->decrypted_keys[0].key, out->decrypted_keys[1].key, true);
}
}
}
}
return true;
}
bool ncaReadContentFile(NcaContext *ctx, void *out, u64 read_size, u64 offset)
{
if (!ctx || !strlen(ctx->content_id_str) || (ctx->storage_id != NcmStorageId_GameCard && !ctx->ncm_storage) || (ctx->storage_id == NcmStorageId_GameCard && !ctx->gamecard_offset) || !out || \
!read_size || offset >= ctx->content_size || (offset + read_size) > ctx->content_size)
{
LOGFILE("Invalid parameters!");
return false;
}
Result rc = 0;
bool ret = false;
if (ctx->storage_id != NcmStorageId_GameCard)
{
/* Retrieve NCA data normally */
/* This strips NAX0 crypto from SD card NCAs (not used on eMMC NCAs) */
rc = ncmContentStorageReadContentIdFile(ctx->ncm_storage, out, read_size, &(ctx->content_id), offset);
ret = R_SUCCEEDED(rc);
if (!ret) LOGFILE("Failed to read 0x%lX bytes block at offset 0x%lX from NCA \"%s\"! (0x%08X) (ncm)", read_size, offset, ctx->content_id_str, rc);
} else {
/* Retrieve NCA data using raw gamecard reads */
/* Fixes NCA read issues with gamecards under HOS < 4.0.0 when using ncmContentStorageReadContentIdFile() */
ret = gamecardReadStorage(out, read_size, ctx->gamecard_offset + offset);
if (!ret) LOGFILE("Failed to read 0x%lX bytes block at offset 0x%lX from NCA \"%s\"! (gamecard)", read_size, offset, ctx->content_id_str);
}
return ret;
}
bool ncaReadFsSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset)
{
return _ncaReadFsSection(ctx, out, read_size, offset, true);
}
void *ncaGenerateEncryptedFsSectionBlock(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, u64 *out_block_size, u64 *out_block_offset)
{
mutexLock(&g_ncaCryptoBufferMutex);
u8 *out = NULL;
bool success = false;
if (!g_ncaCryptoBuffer || !ctx || !ctx->nca_ctx || ctx->section_num >= NCA_FS_HEADER_COUNT || ctx->section_offset < NCA_FULL_HEADER_LENGTH || ctx->section_type >= NcaFsSectionType_Invalid || \
ctx->encryption_type == NcaEncryptionType_Auto || ctx->encryption_type > NcaEncryptionType_Nca0 || !ctx->header || !data || !data_size || data_offset >= ctx->section_size || \
(data_offset + data_size) > ctx->section_size || !out_block_size || !out_block_offset)
{
LOGFILE("Invalid NCA FS section header parameters!");
goto exit;
}
size_t crypt_res = 0;
u64 sector_num = 0;
NcaContext *nca_ctx = (NcaContext*)ctx->nca_ctx;
u64 content_offset = (ctx->section_offset + data_offset);
u64 block_start_offset = 0, block_end_offset = 0, block_size = 0;
u64 plain_chunk_offset = 0;
if (!strlen(nca_ctx->content_id_str) || (nca_ctx->storage_id != NcmStorageId_GameCard && !nca_ctx->ncm_storage) || (nca_ctx->storage_id == NcmStorageId_GameCard && !nca_ctx->gamecard_offset) || \
content_offset >= nca_ctx->content_size || (content_offset + data_size) > nca_ctx->content_size)
{
LOGFILE("Invalid NCA header parameters!");
goto exit;
}
/* Optimization for blocks from plaintext FS sections or blocks that are aligned to the AES-CTR / AES-XTS sector size */
if (ctx->encryption_type == NcaEncryptionType_None || \
((ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0) && !(content_offset % NCA_AES_XTS_SECTOR_SIZE) && !(data_size % NCA_AES_XTS_SECTOR_SIZE)) || \
((ctx->encryption_type == NcaEncryptionType_AesCtr || ctx->encryption_type == NcaEncryptionType_AesCtrEx) && !(content_offset % AES_BLOCK_SIZE) && !(data_size % AES_BLOCK_SIZE)))
{
/* Allocate memory */
out = malloc(data_size);
if (!out)
{
LOGFILE("Unable to allocate 0x%lX bytes buffer! (aligned)", data_size);
goto exit;
}
/* Copy data */
memcpy(out, data, data_size);
/* Encrypt data */
if (ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0)
{
sector_num = ((ctx->encryption_type == NcaEncryptionType_AesXts ? data_offset : (content_offset - NCA_HEADER_LENGTH)) / NCA_AES_XTS_SECTOR_SIZE);
crypt_res = aes128XtsNintendoCrypt(&(ctx->xts_encrypt_ctx), out, out, data_size, sector_num, NCA_AES_XTS_SECTOR_SIZE, true);
if (crypt_res != data_size)
{
LOGFILE("Failed to AES-XTS encrypt 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (aligned)", data_size, content_offset, nca_ctx->content_id_str, ctx->section_num);
goto exit;
}
} else
if (ctx->encryption_type == NcaEncryptionType_AesCtr || ctx->encryption_type == NcaEncryptionType_AesCtrEx)
{
ncaUpdateAesCtrIv(ctx->ctr, content_offset);
aes128CtrContextResetCtr(&(ctx->ctr_ctx), ctx->ctr);
aes128CtrCrypt(&(ctx->ctr_ctx), out, out, data_size);
}
*out_block_size = data_size;
*out_block_offset = content_offset;
success = true;
goto exit;
}
/* Calculate block offsets and size */
block_start_offset = ALIGN_DOWN(data_offset, (ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0) ? NCA_AES_XTS_SECTOR_SIZE : AES_BLOCK_SIZE);
block_end_offset = ALIGN_UP(data_offset + data_size, (ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0) ? NCA_AES_XTS_SECTOR_SIZE : AES_BLOCK_SIZE);
block_size = (block_end_offset - block_start_offset);
plain_chunk_offset = (data_offset - block_start_offset);
content_offset = (ctx->section_offset + block_start_offset);
/* Allocate memory */
out = malloc(block_size);
if (!out)
{
LOGFILE("Unable to allocate 0x%lX bytes buffer! (unaligned)", block_size);
goto exit;
}
/* Read decrypted data using aligned offset and size */
if (!_ncaReadFsSection(ctx, out, block_size, block_start_offset, false))
{
LOGFILE("Failed to read decrypted NCA \"%s\" FS section #%u data block!", nca_ctx->content_id_str, ctx->section_num);
goto exit;
}
/* Replace plaintext data */
memcpy(out + plain_chunk_offset, data, data_size);
/* Reencrypt data */
if (ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0)
{
sector_num = ((ctx->encryption_type == NcaEncryptionType_AesXts ? block_start_offset : (content_offset - NCA_HEADER_LENGTH)) / NCA_AES_XTS_SECTOR_SIZE);
crypt_res = aes128XtsNintendoCrypt(&(ctx->xts_encrypt_ctx), out, out, block_size, sector_num, NCA_AES_XTS_SECTOR_SIZE, true);
if (crypt_res != block_size)
{
LOGFILE("Failed to AES-XTS encrypt 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (aligned)", block_size, content_offset, nca_ctx->content_id_str, ctx->section_num);
goto exit;
}
} else
if (ctx->encryption_type == NcaEncryptionType_AesCtr || ctx->encryption_type == NcaEncryptionType_AesCtrEx)
{
ncaUpdateAesCtrIv(ctx->ctr, content_offset);
aes128CtrContextResetCtr(&(ctx->ctr_ctx), ctx->ctr);
aes128CtrCrypt(&(ctx->ctr_ctx), out, out, block_size);
}
*out_block_size = block_size;
*out_block_offset = content_offset;
success = true;
exit:
mutexUnlock(&g_ncaCryptoBufferMutex);
if (!success && out)
{
free(out);
out = NULL;
}
return out;
}
static size_t aes128XtsNintendoCrypt(Aes128XtsContext *ctx, void *dst, const void *src, size_t size, u64 sector, size_t sector_size, bool encrypt)
{
if (!ctx || !dst || !src || !size || !sector_size || (size % sector_size) != 0)
{
LOGFILE("Invalid parameters!");
return 0;
}
size_t i, crypt_res = 0;
u64 cur_sector = sector;
u8 *dst_u8 = (u8*)dst;
const u8 *src_u8 = (const u8*)src;
for(i = 0; i < size; i += sector_size, cur_sector++)
{
/* We have to force a sector reset on each new sector to actually enable Nintendo AES-XTS cipher tweak */
aes128XtsContextResetSector(ctx, cur_sector, true);
crypt_res = (encrypt ? aes128XtsEncrypt(ctx, dst_u8 + i, src_u8 + i, sector_size) : aes128XtsDecrypt(ctx, dst_u8 + i, src_u8 + i, sector_size));
if (crypt_res != sector_size) break;
}
return i;
}
static bool ncaDecryptHeader(NcaContext *ctx)
{
if (!ctx || !strlen(ctx->content_id_str))
{
LOGFILE("Invalid NCA context!");
return false;
}
u32 i, magic = 0;
size_t crypt_res = 0;
u64 fs_header_offset = 0;
const u8 *header_key = NULL;
Aes128XtsContext hdr_aes_ctx = {0}, nca0_fs_header_ctx = {0};
header_key = keysGetNcaHeaderKey();
aes128XtsContextCreate(&hdr_aes_ctx, header_key, header_key + 0x10, false);
crypt_res = aes128XtsNintendoCrypt(&hdr_aes_ctx, &(ctx->header), &(ctx->header), NCA_HEADER_LENGTH, 0, NCA_AES_XTS_SECTOR_SIZE, false);
if (crypt_res != NCA_HEADER_LENGTH)
{
LOGFILE("Error decrypting partial NCA \"%s\" header!", ctx->content_id_str);
return false;
}
magic = __builtin_bswap32(ctx->header.magic);
switch(magic)
{
case NCA_NCA3_MAGIC:
ctx->format_version = NcaVersion_Nca3;
crypt_res = aes128XtsNintendoCrypt(&hdr_aes_ctx, ctx->header.fs_headers, ctx->header.fs_headers, NCA_FULL_HEADER_LENGTH - NCA_HEADER_LENGTH, 2, NCA_AES_XTS_SECTOR_SIZE, false);
if (crypt_res != (NCA_FULL_HEADER_LENGTH - NCA_HEADER_LENGTH))
{
LOGFILE("Error decrypting NCA3 \"%s\" FS section headers!", ctx->content_id_str);
return false;
}
break;
case NCA_NCA2_MAGIC:
ctx->format_version = NcaVersion_Nca2;
for(i = 0; i < NCA_FS_HEADER_COUNT; i++)
{
if (!ctx->header.fs_entries[i].enable_entry) continue;
crypt_res = aes128XtsNintendoCrypt(&hdr_aes_ctx, &(ctx->header.fs_headers[i]), &(ctx->header.fs_headers[i]), NCA_FS_HEADER_LENGTH, 0, NCA_AES_XTS_SECTOR_SIZE, false);
if (crypt_res != NCA_FS_HEADER_LENGTH)
{
LOGFILE("Error decrypting NCA2 \"%s\" FS section header #%u!", ctx->content_id_str, i);
return false;
}
}
break;
case NCA_NCA0_MAGIC:
ctx->format_version = NcaVersion_Nca0;
/* We first need to decrypt the key area from the NCA0 header in order to access its FS section headers */
if (!ncaDecryptKeyArea(ctx))
{
LOGFILE("Error decrypting NCA0 \"%s\" key area!", ctx->content_id_str);
return false;
}
aes128XtsContextCreate(&nca0_fs_header_ctx, ctx->decrypted_keys[0].key, ctx->decrypted_keys[1].key, false);
for(i = 0; i < NCA_FS_HEADER_COUNT; i++)
{
if (!ctx->header.fs_entries[i].enable_entry) continue;
/* FS headers are not part of NCA0 headers */
fs_header_offset = NCA_FS_ENTRY_BLOCK_OFFSET(ctx->header.fs_entries[i].start_block_offset);
if (!ncaReadContentFile(ctx, &(ctx->header.fs_headers[i]), NCA_FS_HEADER_LENGTH, fs_header_offset))
{
LOGFILE("Failed to read NCA0 \"%s\" FS section header #%u at offset 0x%lX!", ctx->content_id_str, i, fs_header_offset);
return false;
}
crypt_res = aes128XtsNintendoCrypt(&nca0_fs_header_ctx, &(ctx->header.fs_headers[i]), &(ctx->header.fs_headers[i]), NCA_FS_HEADER_LENGTH, \
NCA_NCA0_FS_HEADER_AES_XTS_SECTOR(fs_header_offset), NCA_AES_XTS_SECTOR_SIZE, false);
if (crypt_res != NCA_FS_HEADER_LENGTH)
{
LOGFILE("Error decrypting NCA0 \"%s\" FS section header #%u!", ctx->content_id_str, i);
return false;
}
}
break;
default:
LOGFILE("Invalid NCA \"%s\" magic word! Wrong header key? (0x%08X)", ctx->content_id_str, magic);
return false;
}
return true;
}
static bool ncaDecryptKeyArea(NcaContext *ctx)
{
if (!ctx)
{
LOGFILE("Invalid NCA context!");
return false;
}
Result rc = 0;
const u8 *kek_src = NULL;
u8 key_count, tmp_kek[0x10] = {0};
/* Check if we're dealing with a NCA0 with a plain text key area */
if (ctx->format_version == NcaVersion_Nca0 && !ncaCheckIfVersion0KeyAreaIsEncrypted(ctx))
{
memcpy(ctx->decrypted_keys, ctx->header.encrypted_keys, 0x40);
return true;
}
kek_src = keysGetKeyAreaEncryptionKeySource(ctx->header.kaek_index);
if (!kek_src)
{
LOGFILE("Unable to retrieve KAEK source for index 0x%02X!", ctx->header.kaek_index);
return false;
}
rc = splCryptoGenerateAesKek(kek_src, ctx->key_generation, 0, tmp_kek);
if (R_FAILED(rc))
{
LOGFILE("splCryptoGenerateAesKek failed! (0x%08X)", rc);
return false;
}
key_count = (ctx->format_version == NcaVersion_Nca0 ? 2 : 4);
for(u8 i = 0; i < key_count; i++)
{
rc = splCryptoGenerateAesKey(tmp_kek, ctx->header.encrypted_keys[i].key, ctx->decrypted_keys[i].key);
if (R_FAILED(rc))
{
LOGFILE("splCryptoGenerateAesKey failed! (0x%08X)", rc);
return false;
}
}
return true;
}
NX_INLINE bool ncaCheckIfVersion0KeyAreaIsEncrypted(NcaContext *ctx)
{
if (!ctx || ctx->format_version != NcaVersion_Nca0) return false;
u8 nca0_key_area_hash[SHA256_HASH_SIZE] = {0};
sha256CalculateHash(nca0_key_area_hash, ctx->header.encrypted_keys, 0x40);
if (!memcmp(nca0_key_area_hash, g_nca0KeyAreaHash, SHA256_HASH_SIZE)) return false;
return true;
}
NX_INLINE u8 ncaGetKeyGenerationValue(NcaContext *ctx)
{
if (!ctx) return 0;
return (ctx->header.key_generation > ctx->header.key_generation_old ? ctx->header.key_generation : ctx->header.key_generation_old);
}
NX_INLINE bool ncaCheckRightsIdAvailability(NcaContext *ctx)
{
if (!ctx) return false;
bool rights_id_available = false;
for(u8 i = 0; i < 0x10; i++)
{
if (ctx->header.rights_id.c[i] != 0)
{
rights_id_available = true;
break;
}
}
return rights_id_available;
}
NX_INLINE void ncaInitializeAesCtrIv(u8 *out, const u8 *ctr, u64 offset)
{
if (!out || !ctr) return;
offset >>= 4;
for(u8 i = 0; i < 8; i++)
{
out[i] = ctr[0x8 - i - 1];
out[0x10 - i - 1] = (u8)(offset & 0xFF);
offset >>= 8;
}
}
NX_INLINE void ncaUpdateAesCtrIv(u8 *ctr, u64 offset)
{
if (!ctr) return;
offset >>= 4;
for(u8 i = 0; i < 8; i++)
{
ctr[0x10 - i - 1] = (u8)(offset & 0xFF);
offset >>= 8;
}
}
NX_INLINE void ncaUpdateAesCtrExIv(u8 *ctr, u32 ctr_val, u64 offset)
{
if (!ctr) return;
offset >>= 4;
for(u8 i = 0; i < 8; i++)
{
ctr[0x10 - i - 1] = (u8)(offset & 0xFF);
offset >>= 8;
}
for(u8 i = 0; i < 4; i++)
{
ctr[0x8 - i - 1] = (u8)(ctr_val & 0xFF);
ctr_val >>= 8;
}
}
static bool _ncaReadFsSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset, bool lock)
{
if (lock) mutexLock(&g_ncaCryptoBufferMutex);
bool ret = false;
if (!g_ncaCryptoBuffer || !ctx || !ctx->nca_ctx || ctx->section_num >= NCA_FS_HEADER_COUNT || ctx->section_offset < NCA_FULL_HEADER_LENGTH || ctx->section_type >= NcaFsSectionType_Invalid || \
ctx->encryption_type == NcaEncryptionType_Auto || ctx->encryption_type > NcaEncryptionType_Nca0 || !ctx->header || !out || !read_size || offset >= ctx->section_size || \
(offset + read_size) > ctx->section_size)
{
LOGFILE("Invalid NCA FS section header parameters!");
goto exit;
}
size_t crypt_res = 0;
u64 sector_num = 0;
NcaContext *nca_ctx = (NcaContext*)ctx->nca_ctx;
u64 content_offset = (ctx->section_offset + offset);
u64 block_start_offset = 0, block_end_offset = 0, block_size = 0;
u64 data_start_offset = 0, chunk_size = 0, out_chunk_size = 0;
if (!strlen(nca_ctx->content_id_str) || (nca_ctx->storage_id != NcmStorageId_GameCard && !nca_ctx->ncm_storage) || (nca_ctx->storage_id == NcmStorageId_GameCard && !nca_ctx->gamecard_offset) || \
content_offset >= nca_ctx->content_size || (content_offset + read_size) > nca_ctx->content_size)
{
LOGFILE("Invalid NCA header parameters!");
goto exit;
}
/* Optimization for reads from plaintext FS sections or reads that are aligned to the AES-CTR / AES-XTS sector size */
if (ctx->encryption_type == NcaEncryptionType_None || \
((ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0) && !(content_offset % NCA_AES_XTS_SECTOR_SIZE) && !(read_size % NCA_AES_XTS_SECTOR_SIZE)) || \
((ctx->encryption_type == NcaEncryptionType_AesCtr || ctx->encryption_type == NcaEncryptionType_AesCtrEx) && !(content_offset % AES_BLOCK_SIZE) && !(read_size % AES_BLOCK_SIZE)))
{
/* Read data */
if (!ncaReadContentFile(nca_ctx, out, read_size, content_offset))
{
LOGFILE("Failed to read 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (aligned)", read_size, content_offset, nca_ctx->content_id_str, ctx->section_num);
goto exit;
}
/* Return right away if we're dealing with a plaintext FS section */
if (ctx->encryption_type == NcaEncryptionType_None)
{
ret = true;
goto exit;
}
/* Decrypt data */
if (ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0)
{
sector_num = ((ctx->encryption_type == NcaEncryptionType_AesXts ? offset : (content_offset - NCA_HEADER_LENGTH)) / NCA_AES_XTS_SECTOR_SIZE);
crypt_res = aes128XtsNintendoCrypt(&(ctx->xts_decrypt_ctx), out, out, read_size, sector_num, NCA_AES_XTS_SECTOR_SIZE, false);
if (crypt_res != read_size)
{
LOGFILE("Failed to AES-XTS decrypt 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (aligned)", read_size, content_offset, nca_ctx->content_id_str, ctx->section_num);
goto exit;
}
} else
if (ctx->encryption_type == NcaEncryptionType_AesCtr || ctx->encryption_type == NcaEncryptionType_AesCtrEx)
{
ncaUpdateAesCtrIv(ctx->ctr, content_offset);
aes128CtrContextResetCtr(&(ctx->ctr_ctx), ctx->ctr);
aes128CtrCrypt(&(ctx->ctr_ctx), out, out, read_size);
}
ret = true;
goto exit;
}
/* Calculate offsets and block sizes */
block_start_offset = ALIGN_DOWN(content_offset, (ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0) ? NCA_AES_XTS_SECTOR_SIZE : AES_BLOCK_SIZE);
block_end_offset = ALIGN_UP(content_offset + read_size, (ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0) ? NCA_AES_XTS_SECTOR_SIZE : AES_BLOCK_SIZE);
block_size = (block_end_offset - block_start_offset);
data_start_offset = (content_offset - block_start_offset);
chunk_size = (block_size > NCA_CRYPTO_BUFFER_SIZE ? NCA_CRYPTO_BUFFER_SIZE : block_size);
out_chunk_size = (block_size > NCA_CRYPTO_BUFFER_SIZE ? (NCA_CRYPTO_BUFFER_SIZE - data_start_offset) : read_size);
/* Read data */
if (!ncaReadContentFile(nca_ctx, g_ncaCryptoBuffer, chunk_size, block_start_offset))
{
LOGFILE("Failed to read 0x%lX bytes encrypted data block at offset 0x%lX from NCA \"%s\" FS section #%u! (unaligned)", chunk_size, block_start_offset, nca_ctx->content_id_str, ctx->section_num);
goto exit;
}
/* Decrypt data */
if (ctx->encryption_type == NcaEncryptionType_AesXts || ctx->encryption_type == NcaEncryptionType_Nca0)
{
sector_num = ((ctx->encryption_type == NcaEncryptionType_AesXts ? offset : (content_offset - NCA_HEADER_LENGTH)) / NCA_AES_XTS_SECTOR_SIZE);
crypt_res = aes128XtsNintendoCrypt(&(ctx->xts_decrypt_ctx), g_ncaCryptoBuffer, g_ncaCryptoBuffer, chunk_size, sector_num, NCA_AES_XTS_SECTOR_SIZE, false);
if (crypt_res != chunk_size)
{
LOGFILE("Failed to AES-XTS decrypt 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (unaligned)", chunk_size, block_start_offset, nca_ctx->content_id_str, ctx->section_num);
goto exit;
}
} else
if (ctx->encryption_type == NcaEncryptionType_AesCtr || ctx->encryption_type == NcaEncryptionType_AesCtrEx)
{
ncaUpdateAesCtrIv(ctx->ctr, block_start_offset);
aes128CtrContextResetCtr(&(ctx->ctr_ctx), ctx->ctr);
aes128CtrCrypt(&(ctx->ctr_ctx), g_ncaCryptoBuffer, g_ncaCryptoBuffer, chunk_size);
}
/* Copy decrypted data */
memcpy(out, g_ncaCryptoBuffer + data_start_offset, out_chunk_size);
ret = (block_size > NCA_CRYPTO_BUFFER_SIZE ? _ncaReadFsSection(ctx, (u8*)out + out_chunk_size, read_size - out_chunk_size, offset + out_chunk_size, false) : true);
exit:
if (lock) mutexUnlock(&g_ncaCryptoBufferMutex);
return ret;
}
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