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nxdumptool/source/core/nca.c
Pablo Curiel 1bc1a05f96 Add SHA3 support.
2022-06-25 21:28:31 +02:00

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/*
* nca.c
*
* Copyright (c) 2020-2022, DarkMatterCore <pabloacurielz@gmail.com>.
*
* This file is part of nxdumptool (https://github.com/DarkMatterCore/nxdumptool).
*
* nxdumptool is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* nxdumptool is distributed in the hope that 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 <https://www.gnu.org/licenses/>.
*/
#include "nxdt_utils.h"
#include "nca.h"
#include "keys.h"
#include "aes.h"
#include "rsa.h"
#include "gamecard.h"
#include "title.h"
#define NCA_CRYPTO_BUFFER_SIZE 0x800000 /* 8 MiB. */
/* Global variables. */
static u8 *g_ncaCryptoBuffer = NULL;
static Mutex g_ncaCryptoBufferMutex = 0;
/// Used to verify if the key area from a NCA0 is encrypted.
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
};
/// Used to verify the NCA header main signature.
static const u8 g_ncaHeaderMainSignaturePublicExponent[3] = { 0x01, 0x00, 0x01 };
/* Function prototypes. */
NX_INLINE bool ncaIsFsInfoEntryValid(NcaFsInfo *fs_info);
static bool ncaReadDecryptedHeader(NcaContext *ctx);
static bool ncaDecryptKeyArea(NcaContext *ctx);
static bool ncaEncryptKeyArea(NcaContext *ctx);
static bool ncaVerifyMainSignature(NcaContext *ctx);
NX_INLINE bool ncaIsVersion0KeyAreaEncrypted(NcaContext *ctx);
NX_INLINE u8 ncaGetKeyGenerationValue(NcaContext *ctx);
NX_INLINE bool ncaCheckRightsIdAvailability(NcaContext *ctx);
static bool _ncaReadFsSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset);
static bool _ncaReadAesCtrExStorageFromBktrSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset, u32 ctr_val);
static void ncaCalculateLayerHash(void *dst, const void *src, size_t size, bool use_sha3);
static bool ncaGenerateHashDataPatch(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, void *out, bool is_integrity_patch);
static bool ncaWritePatchToMemoryBuffer(NcaContext *ctx, const void *patch, u64 patch_size, u64 patch_offset, void *buf, u64 buf_size, u64 buf_offset);
static void *_ncaGenerateEncryptedFsSectionBlock(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, u64 *out_block_size, u64 *out_block_offset);
bool ncaAllocateCryptoBuffer(void)
{
bool ret = false;
SCOPED_LOCK(&g_ncaCryptoBufferMutex)
{
if (!g_ncaCryptoBuffer) g_ncaCryptoBuffer = malloc(NCA_CRYPTO_BUFFER_SIZE);
ret = (g_ncaCryptoBuffer != NULL);
}
return ret;
}
void ncaFreeCryptoBuffer(void)
{
SCOPED_LOCK(&g_ncaCryptoBufferMutex)
{
if (!g_ncaCryptoBuffer) break;
free(g_ncaCryptoBuffer);
g_ncaCryptoBuffer = NULL;
}
}
bool ncaInitializeContext(NcaContext *out, u8 storage_id, u8 hfs_partition_type, const NcmContentInfo *content_info, Ticket *tik)
{
NcmContentStorage *ncm_storage = NULL;
u8 fs_header_hash_calc[SHA256_HASH_SIZE] = {0};
u8 valid_fs_section_cnt = 0;
if (!out || (storage_id != NcmStorageId_GameCard && !(ncm_storage = titleGetNcmStorageByStorageId(storage_id))) || \
(storage_id == NcmStorageId_GameCard && (!hfs_partition_type || hfs_partition_type >= GameCardHashFileSystemPartitionType_Count)) || !content_info || \
content_info->content_type > NcmContentType_DeltaFragment)
{
LOG_MSG("Invalid parameters!");
return false;
}
/* Clear output NCA context. */
memset(out, 0, sizeof(NcaContext));
/* 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->content_id), sizeof(NcmContentId));
utilsGenerateHexStringFromData(out->content_id_str, sizeof(out->content_id_str), out->content_id.c, sizeof(out->content_id.c), false);
utilsGenerateHexStringFromData(out->hash_str, sizeof(out->hash_str), out->hash, sizeof(out->hash), false); /* Placeholder, needs to be manually calculated. */
out->content_type = content_info->content_type;
out->id_offset = content_info->id_offset;
titleConvertNcmContentSizeToU64(content_info->size, &(out->content_size));
if (out->content_size < NCA_FULL_HEADER_LENGTH)
{
LOG_MSG("Invalid size for NCA \"%s\"!", out->content_id_str);
return false;
}
if (out->storage_id == NcmStorageId_GameCard)
{
/* Generate gamecard NCA filename. */
char nca_filename[0x30] = {0};
sprintf(nca_filename, "%s.%s", out->content_id_str, out->content_type == NcmContentType_Meta ? "cnmt.nca" : "nca");
/* Retrieve gamecard NCA offset. */
if (!gamecardGetHashFileSystemEntryInfoByName(hfs_partition_type, nca_filename, &(out->gamecard_offset), NULL))
{
LOG_MSG("Error retrieving offset for \"%s\" entry in secure hash FS partition!", nca_filename);
return false;
}
}
/* Read decrypted NCA header and NCA FS section headers. */
if (!ncaReadDecryptedHeader(out))
{
LOG_MSG("Failed to read decrypted NCA \"%s\" header!", out->content_id_str);
return false;
}
if (out->rights_id_available)
{
Ticket tmp_tik = {0};
Ticket *usable_tik = (tik ? tik : &tmp_tik);
/* Retrieve ticket. */
/* This will return true if it has already been retrieved. */
if (tikRetrieveTicketByRightsId(usable_tik, &(out->header.rights_id), out->storage_id == NcmStorageId_GameCard))
{
/* Copy decrypted titlekey. */
memcpy(out->titlekey, usable_tik->dec_titlekey, 0x10);
out->titlekey_retrieved = true;
} else {
LOG_MSG("Error retrieving ticket for NCA \"%s\"!", out->content_id_str);
}
}
/* Parse NCA FS sections. */
for(u8 i = 0; i < NCA_FS_HEADER_COUNT; i++)
{
NcaFsInfo *fs_info = &(out->header.fs_info[i]);
NcaFsSectionContext *fs_ctx = &(out->fs_ctx[i]);
u8 *fs_header_hash = out->header.fs_header_hash[i].hash;
NcaSparseInfo *sparse_info = &(fs_ctx->header.sparse_info);
NcaBucketInfo *sparse_bucket = &(sparse_info->bucket);
/* Fill section context. */
fs_ctx->nca_ctx = out;
fs_ctx->section_num = i;
fs_ctx->section_type = NcaFsSectionType_Invalid; /* Placeholder. */
fs_ctx->has_sparse_layer = (sparse_info->generation != 0);
/* Don't proceed if this NCA FS section isn't populated. */
if (!ncaIsFsInfoEntryValid(fs_info)) continue;
/* Calculate NCA FS section header hash. */
sha256CalculateHash(fs_header_hash_calc, &(fs_ctx->header), sizeof(NcaFsHeader));
/* Don't proceed if there's a checksum mismatch. */
if (memcmp(fs_header_hash_calc, fs_header_hash, SHA256_HASH_SIZE) != 0) continue;
/* Calculate section offset and size. */
fs_ctx->section_offset = NCA_FS_SECTOR_OFFSET(fs_info->start_sector);
fs_ctx->section_size = (NCA_FS_SECTOR_OFFSET(fs_info->end_sector) - fs_ctx->section_offset);
/* Check if we're dealing with an invalid start offset or an empty size. */
if (fs_ctx->section_offset < sizeof(NcaHeader) || !fs_ctx->section_size) continue;
/* Determine FS section hash type. */
fs_ctx->hash_type = fs_ctx->header.hash_type;
if (fs_ctx->hash_type == NcaHashType_Auto || fs_ctx->hash_type == NcaHashType_AutoSha3)
{
switch(fs_ctx->section_num)
{
case 0: /* ExeFS Partition FS. */
case 2: /* Logo Partition FS. */
fs_ctx->hash_type = (fs_ctx->hash_type == NcaHashType_Auto ? NcaHashType_HierarchicalSha256 : NcaHashType_HierarchicalSha3256);
break;
case 1: /* RomFS. */
fs_ctx->hash_type = (fs_ctx->hash_type == NcaHashType_Auto ? NcaHashType_HierarchicalIntegrity : NcaHashType_HierarchicalIntegritySha3);
break;
default:
break;
}
}
if (fs_ctx->hash_type == NcaHashType_Auto || fs_ctx->hash_type == NcaHashType_AutoSha3 || fs_ctx->hash_type > NcaHashType_HierarchicalIntegritySha3) continue;
/* Determine FS section encryption type. */
fs_ctx->encryption_type = (out->format_version == NcaVersion_Nca0 ? NcaEncryptionType_AesXts : fs_ctx->header.encryption_type);
if (fs_ctx->encryption_type == NcaEncryptionType_Auto)
{
switch(fs_ctx->section_num)
{
case 0: /* ExeFS Partition FS. */
case 1: /* RomFS. */
fs_ctx->encryption_type = NcaEncryptionType_AesCtr;
break;
case 2: /* Logo Partition FS. */
fs_ctx->encryption_type = NcaEncryptionType_None;
break;
default:
break;
}
}
if (fs_ctx->encryption_type == NcaEncryptionType_Auto || fs_ctx->encryption_type > NcaEncryptionType_AesCtrExSkipLayerHash) continue;
/* Determine FS section type. */
if (fs_ctx->header.fs_type == NcaFsType_PartitionFs && (fs_ctx->hash_type == NcaHashType_HierarchicalSha256 || fs_ctx->hash_type == NcaHashType_HierarchicalSha3256))
{
fs_ctx->section_type = NcaFsSectionType_PartitionFs;
} else
if (fs_ctx->header.fs_type == NcaFsType_RomFs && (fs_ctx->hash_type == NcaHashType_HierarchicalIntegrity || fs_ctx->hash_type == NcaHashType_HierarchicalIntegritySha3))
{
fs_ctx->section_type = ((fs_ctx->encryption_type == NcaEncryptionType_AesCtrEx || fs_ctx->encryption_type == NcaEncryptionType_AesCtrExSkipLayerHash) ? \
NcaFsSectionType_PatchRomFs : NcaFsSectionType_RomFs);
} else
if (fs_ctx->header.fs_type == NcaFsType_RomFs && fs_ctx->hash_type == NcaHashType_HierarchicalSha256 && out->format_version == NcaVersion_Nca0)
{
fs_ctx->section_type = NcaFsSectionType_Nca0RomFs;
}
if (fs_ctx->section_type >= NcaFsSectionType_Invalid) continue;
/* Check if we should skip hash layer decryption while reading this FS section. */
fs_ctx->skip_hash_layer_crypto = (fs_ctx->encryption_type == NcaEncryptionType_AesCtrSkipLayerHash || fs_ctx->encryption_type == NcaEncryptionType_AesCtrExSkipLayerHash);
if (fs_ctx->skip_hash_layer_crypto)
{
u32 layer_count = 0;
if (fs_ctx->hash_type == NcaHashType_HierarchicalSha256 || fs_ctx->hash_type == NcaHashType_HierarchicalSha3256)
{
layer_count = fs_ctx->header.hash_data.hierarchical_sha256_data.hash_region_count;
if (layer_count <= NCA_HIERARCHICAL_SHA256_MAX_REGION_COUNT)
{
NcaRegion *last_region = &(fs_ctx->header.hash_data.hierarchical_sha256_data.hash_region[layer_count - 1]);
fs_ctx->last_layer_offset = last_region->offset;
fs_ctx->last_layer_size = last_region->size;
}
} else
if (fs_ctx->hash_type == NcaHashType_HierarchicalIntegrity || fs_ctx->hash_type == NcaHashType_HierarchicalIntegritySha3)
{
layer_count = (fs_ctx->header.hash_data.integrity_meta_info.info_level_hash.max_level_count - 1);
if (layer_count == NCA_IVFC_LEVEL_COUNT)
{
NcaHierarchicalIntegrityVerificationLevelInformation *last_level_info = &(fs_ctx->header.hash_data.integrity_meta_info.info_level_hash.level_information[layer_count - 1]);
fs_ctx->last_layer_offset = last_level_info->offset;
fs_ctx->last_layer_size = last_level_info->size;
}
} else {
fs_ctx->skip_hash_layer_crypto = false;
}
}
/* Check if we're dealing with a sparse storage. */
if (fs_ctx->has_sparse_layer)
{
/* Check if the sparse bucket is valid. */
u64 raw_storage_offset = sparse_info->physical_offset;
u64 raw_storage_size = (sparse_bucket->offset + sparse_bucket->size);
if (__builtin_bswap32(sparse_bucket->header.magic) != NCA_BKTR_MAGIC || sparse_bucket->header.version != NCA_BKTR_VERSION || raw_storage_offset < sizeof(NcaHeader) || \
((raw_storage_offset + raw_storage_size) > out->content_size)) continue;
if (!raw_storage_size || !sparse_bucket->header.entry_count)
{
/* Increase valid FS section count but don't set this FS section as enabled, since we can't use it. */
valid_fs_section_cnt++;
continue;
}
/* Set sparse table properties. */
fs_ctx->sparse_table_offset = (sparse_info->physical_offset + sparse_bucket->offset);
fs_ctx->sparse_table_size = sparse_bucket->size;
} else {
/* Check if we're within boundaries. */
if ((fs_ctx->section_offset + fs_ctx->section_size) > out->content_size) continue;
}
/* Initialize crypto data. */
if ((!out->rights_id_available || (out->rights_id_available && out->titlekey_retrieved)) && fs_ctx->encryption_type > NcaEncryptionType_None && \
fs_ctx->encryption_type <= NcaEncryptionType_AesCtrExSkipLayerHash)
{
/* Initialize the partial AES counter for this section. */
aes128CtrInitializePartialCtr(fs_ctx->ctr, fs_ctx->header.aes_ctr_upper_iv.value, fs_ctx->section_offset);
if (fs_ctx->has_sparse_layer)
{
/* Initialize the partial AES counter for the sparse info bucket table. */
NcaAesCtrUpperIv sparse_upper_iv = {0};
memcpy(sparse_upper_iv.value, fs_ctx->header.aes_ctr_upper_iv.value, sizeof(sparse_upper_iv.value));
sparse_upper_iv.generation = ((u32)(sparse_info->generation) << 16);
aes128CtrInitializePartialCtr(fs_ctx->sparse_ctr, sparse_upper_iv.value, fs_ctx->sparse_table_offset);
}
/* Initialize AES context. */
if (out->rights_id_available)
{
/* AES-128-CTR is always used for FS crypto in NCAs with a rights ID. */
aes128CtrContextCreate(&(fs_ctx->ctr_ctx), out->titlekey, fs_ctx->ctr);
if (fs_ctx->has_sparse_layer) aes128CtrContextCreate(&(fs_ctx->sparse_ctr_ctx), out->titlekey, fs_ctx->sparse_ctr);
} else {
if (fs_ctx->encryption_type == NcaEncryptionType_AesXts)
{
/* We need to create two different contexts with AES-128-XTS: one for decryption and another one for encryption. */
aes128XtsContextCreate(&(fs_ctx->xts_decrypt_ctx), out->decrypted_key_area.aes_xts_1, out->decrypted_key_area.aes_xts_2, false);
aes128XtsContextCreate(&(fs_ctx->xts_encrypt_ctx), out->decrypted_key_area.aes_xts_1, out->decrypted_key_area.aes_xts_2, true);
} else
if (fs_ctx->encryption_type >= NcaEncryptionType_AesCtr && fs_ctx->encryption_type <= NcaEncryptionType_AesCtrExSkipLayerHash)
{
/* Patch RomFS sections also use the AES-128-CTR key from the decrypted NCA key area, for some reason. */
aes128CtrContextCreate(&(fs_ctx->ctr_ctx), out->decrypted_key_area.aes_ctr, fs_ctx->ctr);
if (fs_ctx->has_sparse_layer) aes128CtrContextCreate(&(fs_ctx->sparse_ctr_ctx), out->decrypted_key_area.aes_ctr, fs_ctx->sparse_ctr);
}
}
}
/* Enable FS context if we got up to this point. */
fs_ctx->enabled = true;
/* Increase valid NCA FS section count. */
valid_fs_section_cnt++;
}
if (!valid_fs_section_cnt) LOG_MSG("Unable to identify any valid FS sections in NCA \"%s\"!", out->content_id_str);
return (valid_fs_section_cnt > 0);
}
bool ncaReadContentFile(NcaContext *ctx, void *out, u64 read_size, u64 offset)
{
if (!ctx || !*(ctx->content_id_str) || (ctx->storage_id != NcmStorageId_GameCard && !ctx->ncm_storage) || (ctx->storage_id == NcmStorageId_GameCard && !ctx->gamecard_offset) || !out || \
!read_size || (offset + read_size) > ctx->content_size)
{
LOG_MSG("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) LOG_MSG("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) LOG_MSG("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)
{
bool ret = false;
SCOPED_LOCK(&g_ncaCryptoBufferMutex) ret = _ncaReadFsSection(ctx, out, read_size, offset);
return ret;
}
bool ncaReadAesCtrExStorageFromBktrSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset, u32 ctr_val)
{
bool ret = false;
SCOPED_LOCK(&g_ncaCryptoBufferMutex) ret = _ncaReadAesCtrExStorageFromBktrSection(ctx, out, read_size, offset, ctr_val);
return ret;
}
void *ncaGenerateEncryptedFsSectionBlock(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, u64 *out_block_size, u64 *out_block_offset)
{
void *ret = NULL;
SCOPED_LOCK(&g_ncaCryptoBufferMutex) ret = _ncaGenerateEncryptedFsSectionBlock(ctx, data, data_size, data_offset, out_block_size, out_block_offset);
return ret;
}
bool ncaGenerateHierarchicalSha256Patch(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, NcaHierarchicalSha256Patch *out)
{
bool ret = false;
SCOPED_LOCK(&g_ncaCryptoBufferMutex) ret = ncaGenerateHashDataPatch(ctx, data, data_size, data_offset, out, false);
return ret;
}
void ncaWriteHierarchicalSha256PatchToMemoryBuffer(NcaContext *ctx, NcaHierarchicalSha256Patch *patch, void *buf, u64 buf_size, u64 buf_offset)
{
if (!ctx || !*(ctx->content_id_str) || ctx->content_size < NCA_FULL_HEADER_LENGTH || !patch || patch->written || memcmp(patch->content_id.c, ctx->content_id.c, 0x10) != 0 || \
!patch->hash_region_count || patch->hash_region_count > NCA_HIERARCHICAL_SHA256_MAX_REGION_COUNT || !buf || !buf_size || (buf_offset + buf_size) > ctx->content_size) return;
patch->written = true;
for(u32 i = 0; i < patch->hash_region_count; i++)
{
NcaHashDataPatch *hash_region_patch = &(patch->hash_region_patch[i]);
if (hash_region_patch->written) continue;
hash_region_patch->written = ncaWritePatchToMemoryBuffer(ctx, hash_region_patch->data, hash_region_patch->size, hash_region_patch->offset, buf, buf_size, buf_offset);
if (!hash_region_patch->written) patch->written = false;
}
}
bool ncaGenerateHierarchicalIntegrityPatch(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, NcaHierarchicalIntegrityPatch *out)
{
bool ret = false;
SCOPED_LOCK(&g_ncaCryptoBufferMutex) ret = ncaGenerateHashDataPatch(ctx, data, data_size, data_offset, out, true);
return ret;
}
void ncaWriteHierarchicalIntegrityPatchToMemoryBuffer(NcaContext *ctx, NcaHierarchicalIntegrityPatch *patch, void *buf, u64 buf_size, u64 buf_offset)
{
if (!ctx || !*(ctx->content_id_str) || ctx->content_size < NCA_FULL_HEADER_LENGTH || !patch || patch->written || memcmp(patch->content_id.c, ctx->content_id.c, 0x10) != 0 || \
!buf || !buf_size || (buf_offset + buf_size) > ctx->content_size) return;
patch->written = true;
for(u32 i = 0; i < NCA_IVFC_LEVEL_COUNT; i++)
{
NcaHashDataPatch *hash_level_patch = &(patch->hash_level_patch[i]);
if (hash_level_patch->written) continue;
hash_level_patch->written = ncaWritePatchToMemoryBuffer(ctx, hash_level_patch->data, hash_level_patch->size, hash_level_patch->offset, buf, buf_size, buf_offset);
if (!hash_level_patch->written) patch->written = false;
}
}
void ncaSetDownloadDistributionType(NcaContext *ctx)
{
if (!ctx || ctx->content_size < NCA_FULL_HEADER_LENGTH || !*(ctx->content_id_str) || ctx->content_type > NcmContentType_DeltaFragment || \
ctx->header.distribution_type == NcaDistributionType_Download) return;
ctx->header.distribution_type = NcaDistributionType_Download;
LOG_MSG("Set download distribution type to %s NCA \"%s\".", titleGetNcmContentTypeName(ctx->content_type), ctx->content_id_str);
}
bool ncaRemoveTitleKeyCrypto(NcaContext *ctx)
{
if (!ctx || ctx->content_size < NCA_FULL_HEADER_LENGTH || !*(ctx->content_id_str) || ctx->content_type > NcmContentType_DeltaFragment)
{
LOG_MSG("Invalid parameters!");
return false;
}
/* Don't proceed if we're not dealing with a NCA with a populated rights ID field, or if we couldn't retrieve the titlekey for it. */
if (!ctx->rights_id_available || !ctx->titlekey_retrieved) return true;
/* Copy decrypted titlekey to the decrypted NCA key area. This will be reencrypted at a later stage. */
/* AES-128-XTS is not used in FS sections from NCAs with titlekey crypto. */
/* Patch RomFS sections also use the AES-128-CTR key from the decrypted NCA key area, for some reason. */
memcpy(ctx->decrypted_key_area.aes_ctr, ctx->titlekey, AES_128_KEY_SIZE);
/* Encrypt NCA key area. */
if (!ncaEncryptKeyArea(ctx))
{
LOG_MSG("Error encrypting %s NCA \"%s\" key area!", titleGetNcmContentTypeName(ctx->content_type), ctx->content_id_str);
return false;
}
/* Wipe Rights ID. */
memset(&(ctx->header.rights_id), 0, sizeof(FsRightsId));
/* Update context flags. */
ctx->rights_id_available = false;
LOG_MSG("Removed titlekey crypto from %s NCA \"%s\".", titleGetNcmContentTypeName(ctx->content_type), ctx->content_id_str);
return true;
}
bool ncaEncryptHeader(NcaContext *ctx)
{
if (!ctx || !*(ctx->content_id_str) || ctx->content_size < NCA_FULL_HEADER_LENGTH)
{
LOG_MSG("Invalid NCA context!");
return false;
}
/* Safety check: don't encrypt the header if we don't need to. */
if (!ncaIsHeaderDirty(ctx)) return true;
size_t crypt_res = 0;
const u8 *header_key = keysGetNcaHeaderKey();
Aes128XtsContext hdr_aes_ctx = {0}, nca0_fs_header_ctx = {0};
if (!header_key)
{
LOG_MSG("Failed to retrieve NCA header key!");
return false;
}
/* Prepare AES-128-XTS contexts. */
aes128XtsContextCreate(&hdr_aes_ctx, header_key, header_key + AES_128_KEY_SIZE, true);
if (ctx->format_version == NcaVersion_Nca0) aes128XtsContextCreate(&nca0_fs_header_ctx, ctx->decrypted_key_area.aes_xts_1, ctx->decrypted_key_area.aes_xts_2, true);
/* Encrypt NCA header. */
crypt_res = aes128XtsNintendoCrypt(&hdr_aes_ctx, &(ctx->encrypted_header), &(ctx->header), sizeof(NcaHeader), 0, NCA_AES_XTS_SECTOR_SIZE, true);
if (crypt_res != sizeof(NcaHeader))
{
LOG_MSG("Error encrypting NCA \"%s\" header!", ctx->content_id_str);
return false;
}
/* Encrypt NCA FS section headers. */
/* Both NCA2 and NCA3 place the NCA FS section headers right after the NCA header. However, NCA0 places them at the start sector from each NCA FS section. */
for(u8 i = 0; i < NCA_FS_HEADER_COUNT; i++)
{
NcaFsInfo *fs_info = &(ctx->header.fs_info[i]);
NcaFsSectionContext *fs_ctx = &(ctx->fs_ctx[i]);
/* Don't proceed if this NCA FS section isn't populated. */
if (!ncaIsFsInfoEntryValid(fs_info)) continue;
/* The AES-XTS sector number for each NCA FS header varies depending on the NCA format version. */
/* NCA3 uses sector number 0 for the NCA header, then increases it with each new sector (e.g. making the first NCA FS section header use sector number 2, and so on). */
/* NCA2 uses sector number 0 for each NCA FS section header. */
/* NCA0 uses sector number 0 for the NCA header, then uses sector number 0 for the rest of the data and increases it with each new sector. */
Aes128XtsContext *aes_xts_ctx = (ctx->format_version != NcaVersion_Nca0 ? &hdr_aes_ctx : &nca0_fs_header_ctx);
u64 sector = (ctx->format_version == NcaVersion_Nca3 ? (2U + i) : (ctx->format_version == NcaVersion_Nca2 ? 0 : (fs_info->start_sector - 2)));
crypt_res = aes128XtsNintendoCrypt(aes_xts_ctx, &(fs_ctx->encrypted_header), &(fs_ctx->header), sizeof(NcaFsHeader), sector, NCA_AES_XTS_SECTOR_SIZE, true);
if (crypt_res != sizeof(NcaFsHeader))
{
LOG_MSG("Error encrypting NCA%u \"%s\" FS section header #%u!", ctx->format_version, ctx->content_id_str, i);
return false;
}
}
return true;
}
void ncaWriteEncryptedHeaderDataToMemoryBuffer(NcaContext *ctx, void *buf, u64 buf_size, u64 buf_offset)
{
/* Return right away if we're dealing with invalid parameters. */
/* In order to avoid taking up too much execution time when this function is called (ideally inside a loop), we won't use ncaIsHeaderDirty() here. Let the user take care of it instead. */
if (!ctx || ctx->header_written || ctx->content_size < NCA_FULL_HEADER_LENGTH || !buf || !buf_size || (buf_offset + buf_size) > ctx->content_size) return;
ctx->header_written = true;
/* Attempt to write the NCA header. */
/* Return right away if the NCA header was only partially written. */
if (buf_offset < sizeof(NcaHeader) && !ncaWritePatchToMemoryBuffer(ctx, &(ctx->encrypted_header), sizeof(NcaHeader), 0, buf, buf_size, buf_offset))
{
ctx->header_written = false;
return;
}
/* Attempt to write NCA FS section headers. */
for(u8 i = 0; i < NCA_FS_HEADER_COUNT; i++)
{
NcaFsSectionContext *fs_ctx = &(ctx->fs_ctx[i]);
if (!fs_ctx->enabled || fs_ctx->header_written) continue;
u64 fs_header_offset = (ctx->format_version != NcaVersion_Nca0 ? (sizeof(NcaHeader) + (i * sizeof(NcaFsHeader))) : fs_ctx->section_offset);
fs_ctx->header_written = ncaWritePatchToMemoryBuffer(ctx, &(fs_ctx->encrypted_header), sizeof(NcaFsHeader), fs_header_offset, buf, buf_size, buf_offset);
if (!fs_ctx->header_written) ctx->header_written = false;
}
}
void ncaUpdateContentIdAndHash(NcaContext *ctx, u8 hash[SHA256_HASH_SIZE])
{
if (!ctx) return;
/* Update content ID. */
memcpy(ctx->content_id.c, hash, sizeof(ctx->content_id.c));
utilsGenerateHexStringFromData(ctx->content_id_str, sizeof(ctx->content_id_str), ctx->content_id.c, sizeof(ctx->content_id.c), false);
/* Update content hash. */
memcpy(ctx->hash, hash, sizeof(ctx->hash));
utilsGenerateHexStringFromData(ctx->hash_str, sizeof(ctx->hash_str), ctx->hash, sizeof(ctx->hash), false);
}
const char *ncaGetFsSectionTypeName(NcaFsSectionContext *ctx)
{
NcaContext *nca_ctx = NULL;
const char *str = "Invalid";
bool is_exefs = false;
if (!ctx || !ctx->enabled || !(nca_ctx = (NcaContext*)ctx->nca_ctx)) return str;
is_exefs = (nca_ctx->content_type == NcmContentType_Program && ctx->section_num == 0);
switch(ctx->section_type)
{
case NcaFsSectionType_PartitionFs:
if (ctx->has_sparse_layer)
{
str = (is_exefs ? "ExeFS (update required)" : "Partition FS (update required)");
} else {
str = (is_exefs ? "ExeFS" : "Partition FS");
}
break;
case NcaFsSectionType_RomFs:
str = (ctx->has_sparse_layer ? "RomFS (update required)" : "RomFS");
break;
case NcaFsSectionType_PatchRomFs:
str = "Patch RomFS (base required)";
break;
case NcaFsSectionType_Nca0RomFs:
str = "NCA0 RomFS";
break;
default:
break;
}
return str;
}
NX_INLINE bool ncaIsFsInfoEntryValid(NcaFsInfo *fs_info)
{
if (!fs_info) return false;
NcaFsInfo tmp_fs_info = {0};
return (memcmp(&tmp_fs_info, fs_info, sizeof(NcaFsInfo)) != 0);
}
static bool ncaReadDecryptedHeader(NcaContext *ctx)
{
if (!ctx || !*(ctx->content_id_str) || ctx->content_size < NCA_FULL_HEADER_LENGTH)
{
LOG_MSG("Invalid NCA context!");
return false;
}
u32 magic = 0;
size_t crypt_res = 0;
const u8 *header_key = keysGetNcaHeaderKey();
Aes128XtsContext hdr_aes_ctx = {0}, nca0_fs_header_ctx = {0};
if (!header_key)
{
LOG_MSG("Failed to retrieve NCA header key!");
return false;
}
/* Read NCA header. */
if (!ncaReadContentFile(ctx, &(ctx->encrypted_header), sizeof(NcaHeader), 0))
{
LOG_MSG("Failed to read NCA \"%s\" header!", ctx->content_id_str);
return false;
}
/* Prepare NCA header AES-128-XTS context. */
aes128XtsContextCreate(&hdr_aes_ctx, header_key, header_key + AES_128_KEY_SIZE, false);
/* Decrypt NCA header. */
crypt_res = aes128XtsNintendoCrypt(&hdr_aes_ctx, &(ctx->header), &(ctx->encrypted_header), sizeof(NcaHeader), 0, NCA_AES_XTS_SECTOR_SIZE, false);
magic = __builtin_bswap32(ctx->header.magic);
if (crypt_res != sizeof(NcaHeader) || (magic != NCA_NCA3_MAGIC && magic != NCA_NCA2_MAGIC && magic != NCA_NCA0_MAGIC) || ctx->header.content_size != ctx->content_size)
{
LOG_MSG("Error decrypting NCA \"%s\" header!", ctx->content_id_str);
return false;
}
/* Fill additional NCA context info. */
ctx->format_version = (magic == NCA_NCA3_MAGIC ? NcaVersion_Nca3 : (magic == NCA_NCA2_MAGIC ? NcaVersion_Nca2 : NcaVersion_Nca0));
ctx->key_generation = ncaGetKeyGenerationValue(ctx);
ctx->rights_id_available = ncaCheckRightsIdAvailability(ctx);
sha256CalculateHash(ctx->header_hash, &(ctx->header), sizeof(NcaHeader));
ctx->valid_main_signature = ncaVerifyMainSignature(ctx);
/* Decrypt NCA key area (if needed). */
if (!ctx->rights_id_available && !ncaDecryptKeyArea(ctx))
{
LOG_MSG("Error decrypting NCA \"%s\" key area!", ctx->content_id_str);
return false;
}
/* Prepare NCA0 FS header AES-128-XTS context (if needed). */
if (ctx->format_version == NcaVersion_Nca0) aes128XtsContextCreate(&nca0_fs_header_ctx, ctx->decrypted_key_area.aes_xts_1, ctx->decrypted_key_area.aes_xts_2, false);
/* Read decrypted NCA FS section headers. */
/* Both NCA2 and NCA3 place the NCA FS section headers right after the NCA header. However, NCA0 places them at the start sector from each NCA FS section. */
for(u8 i = 0; i < NCA_FS_HEADER_COUNT; i++)
{
NcaFsInfo *fs_info = &(ctx->header.fs_info[i]);
NcaFsSectionContext *fs_ctx = &(ctx->fs_ctx[i]);
/* Don't proceed if this NCA FS section isn't populated. */
if (!ncaIsFsInfoEntryValid(fs_info)) continue;
/* Read NCA FS section header. */
u64 fs_header_offset = (ctx->format_version != NcaVersion_Nca0 ? (sizeof(NcaHeader) + (i * sizeof(NcaFsHeader))) : NCA_FS_SECTOR_OFFSET(fs_info->start_sector));
if (!ncaReadContentFile(ctx, &(fs_ctx->encrypted_header), sizeof(NcaFsHeader), fs_header_offset))
{
LOG_MSG("Failed to read NCA%u \"%s\" FS section header #%u at offset 0x%lX!", ctx->format_version, ctx->content_id_str, i, fs_header_offset);
return false;
}
/* The AES-XTS sector number for each NCA FS header varies depending on the NCA format version. */
/* NCA3 uses sector number 0 for the NCA header, then increases it with each new sector (e.g. making the first NCA FS section header use sector number 2, and so on). */
/* NCA2 uses sector number 0 for each NCA FS section header. */
/* NCA0 uses sector number 0 for the NCA header, then uses sector number 0 for the rest of the data and increases it with each new sector. */
Aes128XtsContext *aes_xts_ctx = (ctx->format_version != NcaVersion_Nca0 ? &hdr_aes_ctx : &nca0_fs_header_ctx);
u64 sector = (ctx->format_version == NcaVersion_Nca3 ? (2U + i) : (ctx->format_version == NcaVersion_Nca2 ? 0 : (fs_info->start_sector - 2)));
crypt_res = aes128XtsNintendoCrypt(aes_xts_ctx, &(fs_ctx->header), &(fs_ctx->encrypted_header), sizeof(NcaFsHeader), sector, NCA_AES_XTS_SECTOR_SIZE, false);
if (crypt_res != sizeof(NcaFsHeader))
{
LOG_MSG("Error decrypting NCA%u \"%s\" FS section header #%u!", ctx->format_version, ctx->content_id_str, i);
return false;
}
}
return true;
}
static bool ncaDecryptKeyArea(NcaContext *ctx)
{
if (!ctx)
{
LOG_MSG("Invalid NCA context!");
return false;
}
const u8 null_key[AES_128_KEY_SIZE] = {0};
u8 key_count = NCA_KEY_AREA_USED_KEY_COUNT;
if (ctx->format_version == NcaVersion_Nca0) key_count--;
/* Check if we're dealing with a NCA0 with a plaintext key area. */
if (ncaIsVersion0KeyAreaEncrypted(ctx))
{
memcpy(&(ctx->decrypted_key_area), &(ctx->header.encrypted_key_area), sizeof(NcaDecryptedKeyArea));
return true;
}
/* Clear decrypted key area. */
memset(&(ctx->decrypted_key_area), 0, sizeof(NcaDecryptedKeyArea));
/* Process key area. */
for(u8 i = 0; i < key_count; i++)
{
const u8 *src_key = ctx->header.encrypted_key_area.keys[i];
u8 *dst_key = ctx->decrypted_key_area.keys[i];
/* Don't proceed if we're dealing with a null key. */
if (!memcmp(src_key, null_key, AES_128_KEY_SIZE)) continue;
/* Decrypt current key area entry. */
if (!keysDecryptNcaKeyAreaEntry(ctx->header.kaek_index, ctx->key_generation, dst_key, src_key))
{
LOG_MSG("Failed to decrypt NCA key area entry #%u!", i);
return false;
}
}
return true;
}
static bool ncaEncryptKeyArea(NcaContext *ctx)
{
if (!ctx)
{
LOG_MSG("Invalid NCA context!");
return false;
}
u8 key_count = NCA_KEY_AREA_USED_KEY_COUNT;
if (ctx->format_version == NcaVersion_Nca0) key_count--;
const u8 *kaek = NULL, null_key[AES_128_KEY_SIZE] = {0};
Aes128Context key_area_ctx = {0};
/* Check if we're dealing with a NCA0 with a plaintext key area. */
if (ncaIsVersion0KeyAreaEncrypted(ctx))
{
memcpy(&(ctx->header.encrypted_key_area), &(ctx->decrypted_key_area), sizeof(NcaDecryptedKeyArea));
return true;
}
/* Get KAEK for these key generation and KAEK index values. */
kaek = keysGetNcaKeyAreaEncryptionKey(ctx->header.kaek_index, ctx->key_generation);
if (!kaek)
{
LOG_MSG("Unable to retrieve KAEK for KAEK index 0x%02X and key generation 0x%02X!", ctx->header.kaek_index, ctx->key_generation);
return false;
}
/* Clear encrypted key area. */
memset(&(ctx->header.encrypted_key_area), 0, sizeof(NcaEncryptedKeyArea));
/* Initialize AES-128-ECB encryption context using the retrieved KAEK. */
aes128ContextCreate(&key_area_ctx, kaek, true);
/* Process key area. */
for(u8 i = 0; i < key_count; i++)
{
const u8 *src_key = ctx->decrypted_key_area.keys[i];
u8 *dst_key = ctx->header.encrypted_key_area.keys[i];
/* Don't proceed if we're dealing with a null key. */
if (!memcmp(src_key, null_key, AES_128_KEY_SIZE)) continue;
/* Encrypt current key area entry. */
aes128EncryptBlock(&key_area_ctx, dst_key, src_key);
}
return true;
}
static bool ncaVerifyMainSignature(NcaContext *ctx)
{
if (!ctx)
{
LOG_MSG("Invalid NCA context!");
return false;
}
/* Retrieve modulus for the NCA main signature. */
const u8 *modulus = keysGetNcaMainSignatureModulus(ctx->header.main_signature_key_generation);
if (!modulus) return false;
/* Verify NCA signature. */
return rsa2048VerifySha256BasedPssSignature(&(ctx->header.magic), NCA_SIGNATURE_AREA_SIZE, ctx->header.main_signature, modulus, g_ncaHeaderMainSignaturePublicExponent, \
sizeof(g_ncaHeaderMainSignaturePublicExponent));
}
NX_INLINE bool ncaIsVersion0KeyAreaEncrypted(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_key_area), 4 * AES_128_KEY_SIZE);
return (memcmp(nca0_key_area_hash, g_nca0KeyAreaHash, SHA256_HASH_SIZE) != 0);
}
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;
for(u8 i = 0; i < 0x10; i++)
{
if (ctx->header.rights_id.c[i]) return true;
}
return false;
}
static bool _ncaReadFsSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset)
{
if (!g_ncaCryptoBuffer || !ctx || !ctx->enabled || !ctx->nca_ctx || ctx->section_num >= NCA_FS_HEADER_COUNT || ctx->section_offset < sizeof(NcaHeader) || \
ctx->section_type >= NcaFsSectionType_Invalid || ctx->encryption_type == NcaEncryptionType_Auto || ctx->encryption_type > NcaEncryptionType_AesCtrExSkipLayerHash || \
!out || !read_size || (offset + read_size) > ctx->section_size)
{
LOG_MSG("Invalid NCA FS section header parameters!");
return false;
}
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;
bool ret = false;
if (!*(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) || \
(nca_ctx->format_version != NcaVersion_Nca0 && nca_ctx->format_version != NcaVersion_Nca2 && nca_ctx->format_version != NcaVersion_Nca3) || (content_offset + read_size) > nca_ctx->content_size)
{
LOG_MSG("Invalid NCA header parameters!");
goto end;
}
/* Check if we're supposed to read a hash layer without encryption. */
if (ctx->skip_hash_layer_crypto)
{
if ((offset + read_size) <= ctx->last_layer_offset || (ctx->last_layer_offset + ctx->last_layer_size) <= offset)
{
/* Easy route. Just read the plaintext data we need and bail out. */
ret = ncaReadContentFile(nca_ctx, out, read_size, content_offset);
if (!ret) LOG_MSG("Failed to read 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (plaintext hash layer) (#1).", read_size, content_offset, \
nca_ctx->content_id_str, ctx->section_num);
goto end;
} else
if ((offset < ctx->last_layer_offset && (offset + read_size) > ctx->last_layer_offset && (offset + read_size) <= (ctx->last_layer_offset + ctx->last_layer_size)) || \
(ctx->last_layer_offset < offset && (ctx->last_layer_offset + ctx->last_layer_size) > offset && (ctx->last_layer_offset + ctx->last_layer_size) < (offset + read_size)))
{
/* Handle reads that span across both plaintext hash layers and encrypted FS area. */
bool plaintext_first = (offset < ctx->last_layer_offset);
/* Calculate offsets and block sizes. */
block_start_offset = content_offset;
block_end_offset = (ctx->section_offset + (plaintext_first ? ctx->last_layer_offset : (ctx->last_layer_offset + ctx->last_layer_size)));
block_size = (block_end_offset - block_start_offset);
if (plaintext_first)
{
/* Read plaintext area. Use NCA-relative offset. */
if (!ncaReadContentFile(nca_ctx, out, block_size, block_start_offset))
{
LOG_MSG("Failed to read 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (plaintext hash layer) (#2).", block_size, block_start_offset, \
nca_ctx->content_id_str, ctx->section_num);
goto end;
}
/* Read encrypted area. Use FS-section-relative offset. */
ret = _ncaReadFsSection(ctx, (u8*)out + block_size, read_size - block_size, offset + block_size);
} else {
/* Read encrypted area. Use FS-section-relative offset. */
if (!_ncaReadFsSection(ctx, out, block_size, offset)) goto end;
/* Read plaintext area. Use NCA-relative offset. */
ret = ncaReadContentFile(nca_ctx, (u8*)out + block_size, read_size - block_size, block_end_offset);
if (!ret) LOG_MSG("Failed to read 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (plaintext hash layer) (#3).", read_size - block_size, \
block_end_offset, nca_ctx->content_id_str, ctx->section_num);
}
goto end;
} else
if (offset < ctx->last_layer_offset && (offset + read_size) > (ctx->last_layer_offset + ctx->last_layer_size))
{
/* Handle plaintext hash layer + encrypted FS area + plaintext hash layer reads. */
u8 *out_u8 = (u8*)out;
/* Read plaintext area. Use NCA-relative offset. */
block_start_offset = content_offset;
block_end_offset = (ctx->section_offset + ctx->last_layer_offset);
block_size = (block_end_offset - block_start_offset);
if (!ncaReadContentFile(nca_ctx, out_u8, block_size, block_start_offset))
{
LOG_MSG("Failed to read 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (plaintext hash layer) (#4).", block_size, block_start_offset, \
nca_ctx->content_id_str, ctx->section_num);
goto end;
}
/* Read encrypted area. Use FS-section-relative offset. */
out_u8 += block_size;
block_start_offset = ctx->last_layer_offset;
block_size = ctx->last_layer_size;
if (!_ncaReadFsSection(ctx, out_u8, block_size, block_start_offset)) goto end;
/* Read plaintext area. Use NCA-relative offset. */
out_u8 += block_size;
block_start_offset = (block_end_offset + block_size);
block_end_offset = (content_offset + read_size);
block_size = (block_end_offset - block_start_offset);
ret = ncaReadContentFile(nca_ctx, out_u8, block_size, block_start_offset);
if (!ret) LOG_MSG("Failed to read 0x%lX bytes data block at offset 0x%lX from NCA \"%s\" FS section #%u! (plaintext hash layer) (#5).", block_size, block_start_offset, \
nca_ctx->content_id_str, ctx->section_num);
goto end;
}
}
/* 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 && !(content_offset % NCA_AES_XTS_SECTOR_SIZE) && !(read_size % NCA_AES_XTS_SECTOR_SIZE)) || \
(ctx->encryption_type >= NcaEncryptionType_AesCtr && ctx->encryption_type <= NcaEncryptionType_AesCtrExSkipLayerHash && !(content_offset % AES_BLOCK_SIZE) && !(read_size % AES_BLOCK_SIZE)))
{
/* Read data. */
if (!ncaReadContentFile(nca_ctx, out, read_size, content_offset))
{
LOG_MSG("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 end;
}
/* Return right away if we're dealing with a plaintext FS section. */
if (ctx->encryption_type == NcaEncryptionType_None)
{
ret = true;
goto end;
}
/* Decrypt data. */
if (ctx->encryption_type == NcaEncryptionType_AesXts)
{
sector_num = ((nca_ctx->format_version != NcaVersion_Nca0 ? offset : (content_offset - sizeof(NcaHeader))) / 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)
{
LOG_MSG("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 end;
}
} else
if (ctx->encryption_type >= NcaEncryptionType_AesCtr && ctx->encryption_type <= NcaEncryptionType_AesCtrExSkipLayerHash)
{
aes128CtrUpdatePartialCtr(ctx->ctr, content_offset);
aes128CtrContextResetCtr(&(ctx->ctr_ctx), ctx->ctr);
aes128CtrCrypt(&(ctx->ctr_ctx), out, out, read_size);
}
ret = true;
goto end;
}
/* Calculate offsets and block sizes. */
block_start_offset = ALIGN_DOWN(content_offset, ctx->encryption_type == NcaEncryptionType_AesXts ? NCA_AES_XTS_SECTOR_SIZE : AES_BLOCK_SIZE);
block_end_offset = ALIGN_UP(content_offset + read_size, ctx->encryption_type == NcaEncryptionType_AesXts ? 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))
{
LOG_MSG("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 end;
}
/* Decrypt data. */
if (ctx->encryption_type == NcaEncryptionType_AesXts)
{
sector_num = ((nca_ctx->format_version != NcaVersion_Nca0 ? offset : (content_offset - sizeof(NcaHeader))) / 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)
{
LOG_MSG("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 end;
}
} else
if (ctx->encryption_type >= NcaEncryptionType_AesCtr && ctx->encryption_type <= NcaEncryptionType_AesCtrExSkipLayerHash)
{
aes128CtrUpdatePartialCtr(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) : true);
end:
return ret;
}
static bool _ncaReadAesCtrExStorageFromBktrSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset, u32 ctr_val)
{
if (!g_ncaCryptoBuffer || !ctx || !ctx->enabled || !ctx->nca_ctx || ctx->section_num >= NCA_FS_HEADER_COUNT || ctx->section_offset < sizeof(NcaHeader) || \
ctx->section_type != NcaFsSectionType_PatchRomFs || (ctx->encryption_type != NcaEncryptionType_AesCtrEx && ctx->encryption_type != NcaEncryptionType_AesCtrExSkipLayerHash) || \
!out || !read_size || (offset + read_size) > ctx->section_size)
{
LOG_MSG("Invalid NCA FS section header parameters!");
return false;
}
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;
bool ret = false;
if (!*(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 + read_size) > nca_ctx->content_size)
{
LOG_MSG("Invalid NCA header parameters!");
goto end;
}
/* Optimization for reads that are aligned to the AES-CTR sector size. */
if (!(content_offset % AES_BLOCK_SIZE) && !(read_size % AES_BLOCK_SIZE))
{
/* Read data. */
if (!ncaReadContentFile(nca_ctx, out, read_size, content_offset))
{
LOG_MSG("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 end;
}
/* Decrypt data */
aes128CtrUpdatePartialCtrEx(ctx->ctr, ctr_val, content_offset);
aes128CtrContextResetCtr(&(ctx->ctr_ctx), ctx->ctr);
aes128CtrCrypt(&(ctx->ctr_ctx), out, out, read_size);
ret = true;
goto end;
}
/* Calculate offsets and block sizes. */
block_start_offset = ALIGN_DOWN(content_offset, AES_BLOCK_SIZE);
block_end_offset = ALIGN_UP(content_offset + read_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))
{
LOG_MSG("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 end;
}
/* Decrypt data. */
aes128CtrUpdatePartialCtrEx(ctx->ctr, ctr_val, 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 ? _ncaReadAesCtrExStorageFromBktrSection(ctx, (u8*)out + out_chunk_size, read_size - out_chunk_size, offset + out_chunk_size, ctr_val) : true);
end:
return ret;
}
static void ncaCalculateLayerHash(void *dst, const void *src, size_t size, bool use_sha3)
{
if (use_sha3)
{
sha256CalculateHash(dst, src, size);
} else {
sha3256CalculateHash(dst, src, size);
}
}
/* In this function, the term "layer" is used as a generic way to refer to both HierarchicalSha256 hash regions and HierarchicalIntegrity verification levels. */
static bool ncaGenerateHashDataPatch(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, void *out, bool is_integrity_patch)
{
NcaContext *nca_ctx = NULL;
NcaHierarchicalSha256Patch *hierarchical_sha256_patch = (!is_integrity_patch ? ((NcaHierarchicalSha256Patch*)out) : NULL);
NcaHierarchicalIntegrityPatch *hierarchical_integrity_patch = (is_integrity_patch ? ((NcaHierarchicalIntegrityPatch*)out) : NULL);
u8 *cur_data = NULL;
u64 cur_data_offset = data_offset;
u64 cur_data_size = data_size;
u32 layer_count = 0;
u8 *parent_layer_block = NULL, *cur_layer_block = NULL;
u64 last_layer_size = 0;
bool use_sha3 = false, success = false;
if (!ctx || !ctx->enabled || ctx->has_sparse_layer || !(nca_ctx = (NcaContext*)ctx->nca_ctx) || (!is_integrity_patch && ((ctx->hash_type != NcaHashType_HierarchicalSha256 && \
ctx->hash_type != NcaHashType_HierarchicalSha3256) || !ctx->header.hash_data.hierarchical_sha256_data.hash_block_size || \
!(layer_count = ctx->header.hash_data.hierarchical_sha256_data.hash_region_count) || layer_count > NCA_HIERARCHICAL_SHA256_MAX_REGION_COUNT || \
!(last_layer_size = ctx->header.hash_data.hierarchical_sha256_data.hash_region[layer_count - 1].size))) || \
(is_integrity_patch && ((ctx->hash_type != NcaHashType_HierarchicalIntegrity && ctx->hash_type != NcaHashType_HierarchicalIntegritySha3) || \
!(layer_count = (ctx->header.hash_data.integrity_meta_info.info_level_hash.max_level_count - 1)) || layer_count != NCA_IVFC_LEVEL_COUNT || \
!(last_layer_size = ctx->header.hash_data.integrity_meta_info.info_level_hash.level_information[NCA_IVFC_LEVEL_COUNT - 1].size))) || !data || !data_size || \
(data_offset + data_size) > last_layer_size || !out || ctx->encryption_type == NcaEncryptionType_Auto || ctx->encryption_type == NcaEncryptionType_AesCtrEx || \
ctx->encryption_type >= NcaEncryptionType_AesCtrExSkipLayerHash)
{
LOG_MSG("Invalid parameters!");
goto end;
}
/* Clear output patch. */
if (!is_integrity_patch)
{
ncaFreeHierarchicalSha256Patch(hierarchical_sha256_patch);
} else {
ncaFreeHierarchicalIntegrityPatch(hierarchical_integrity_patch);
}
/* Check if we should use SHA3-256 instead of SHA-256 for layer hash calculation. */
use_sha3 = (ctx->hash_type == NcaHashType_HierarchicalSha3256 || ctx->hash_type == NcaHashType_HierarchicalIntegritySha3);
/* Process each layer. */
for(u32 i = layer_count; i > 0; i--)
{
u64 hash_block_size = 0;
u64 cur_layer_offset = 0, cur_layer_size = 0;
u64 cur_layer_read_start_offset = 0, cur_layer_read_end_offset = 0, cur_layer_read_size = 0, cur_layer_read_patch_offset = 0;
u64 parent_layer_offset = 0, parent_layer_size = 0;
u64 parent_layer_read_start_offset = 0, parent_layer_read_size = 0;
NcaHashDataPatch *cur_layer_patch = NULL;
/* Retrieve current layer properties. */
hash_block_size = (!is_integrity_patch ? ctx->header.hash_data.hierarchical_sha256_data.hash_block_size : \
NCA_IVFC_BLOCK_SIZE(ctx->header.hash_data.integrity_meta_info.info_level_hash.level_information[i - 1].block_order));
cur_layer_offset = (!is_integrity_patch ? ctx->header.hash_data.hierarchical_sha256_data.hash_region[i - 1].offset : \
ctx->header.hash_data.integrity_meta_info.info_level_hash.level_information[i - 1].offset);
cur_layer_size = (!is_integrity_patch ? ctx->header.hash_data.hierarchical_sha256_data.hash_region[i - 1].size : \
ctx->header.hash_data.integrity_meta_info.info_level_hash.level_information[i - 1].size);
/* Retrieve parent layer properties. */
/* If this is the master layer, then no properties are retrieved, since it is verified by the master hash from the HashData block in the NCA FS section header. */
if (i > 1)
{
parent_layer_offset = (!is_integrity_patch ? ctx->header.hash_data.hierarchical_sha256_data.hash_region[i - 2].offset : \
ctx->header.hash_data.integrity_meta_info.info_level_hash.level_information[i - 2].offset);
parent_layer_size = (!is_integrity_patch ? ctx->header.hash_data.hierarchical_sha256_data.hash_region[i - 2].size : \
ctx->header.hash_data.integrity_meta_info.info_level_hash.level_information[i - 2].size);
}
/* Validate layer properties. */
if (hash_block_size <= 1 || !cur_layer_size || (cur_layer_offset + cur_layer_size) > ctx->section_size || (i > 1 && (!parent_layer_size || \
(parent_layer_offset + parent_layer_size) > ctx->section_size)))
{
LOG_MSG("Invalid hierarchical parent/child layer!");
goto end;
}
/* Retrieve pointer to the current layer patch. */
cur_layer_patch = (!is_integrity_patch ? &(hierarchical_sha256_patch->hash_region_patch[i - 1]) : &(hierarchical_integrity_patch->hash_level_patch[i - 1]));
/* Calculate required offsets and sizes. */
if (i > 1)
{
/* HierarchicalSha256 hash region with index 1 through 4, or HierarchicalIntegrity verification level with index 1 through 5. */
cur_layer_read_start_offset = (cur_layer_offset + ALIGN_DOWN(cur_data_offset, hash_block_size));
cur_layer_read_end_offset = (cur_layer_offset + ALIGN_UP(cur_data_offset + cur_data_size, hash_block_size));
cur_layer_read_size = (cur_layer_read_end_offset - cur_layer_read_start_offset);
parent_layer_read_start_offset = ((cur_data_offset / hash_block_size) * SHA256_HASH_SIZE);
parent_layer_read_size = ((cur_layer_read_size / hash_block_size) * SHA256_HASH_SIZE);
} else {
/* HierarchicalSha256 master hash region, or HierarchicalIntegrity master verification level. Both with index 0. */
/* The master hash is calculated over the whole layer and saved to the HashData block from the NCA FS section header. */
cur_layer_read_start_offset = cur_layer_offset;
cur_layer_read_end_offset = (cur_layer_offset + cur_layer_size);
cur_layer_read_size = cur_layer_size;
}
cur_layer_read_patch_offset = (cur_data_offset - ALIGN_DOWN(cur_data_offset, hash_block_size));
/* Allocate memory for our current layer block. */
cur_layer_block = calloc(cur_layer_read_size, sizeof(u8));
if (!cur_layer_block)
{
LOG_MSG("Unable to allocate 0x%lX bytes for hierarchical layer #%u data block! (current).", cur_layer_read_size, i - 1);
goto end;
}
/* Adjust current layer read size to avoid read errors (if needed). */
if (cur_layer_read_end_offset > (cur_layer_offset + cur_layer_size))
{
cur_layer_read_end_offset = (cur_layer_offset + cur_layer_size);
cur_layer_read_size = (cur_layer_read_end_offset - cur_layer_read_start_offset);
}
/* Read current layer block. */
if (!_ncaReadFsSection(ctx, cur_layer_block, cur_layer_read_size, cur_layer_read_start_offset))
{
LOG_MSG("Failed to read 0x%lX bytes long hierarchical layer #%u data block from offset 0x%lX! (current).", cur_layer_read_size, i - 1, cur_layer_read_start_offset);
goto end;
}
/* Replace current layer block data. */
memcpy(cur_layer_block + cur_layer_read_patch_offset, (i == layer_count ? data : cur_data), cur_data_size);
/* Recalculate hashes. */
if (i > 1)
{
/* Allocate memory for our parent layer block. */
parent_layer_block = calloc(parent_layer_read_size, sizeof(u8));
if (!parent_layer_block)
{
LOG_MSG("Unable to allocate 0x%lX bytes for hierarchical layer #%u data block! (parent).", parent_layer_read_size, i - 2);
goto end;
}
/* Read parent layer block. */
if (!_ncaReadFsSection(ctx, parent_layer_block, parent_layer_read_size, parent_layer_offset + parent_layer_read_start_offset))
{
LOG_MSG("Failed to read 0x%lX bytes long hierarchical layer #%u data block from offset 0x%lX! (parent).", parent_layer_read_size, i - 2, parent_layer_read_start_offset);
goto end;
}
/* HierarchicalSha256: size is truncated for blocks smaller than the hash block size. */
/* HierarchicalIntegrity: size *isn't* truncated for blocks smaller than the hash block size, so we just keep using the same hash block size throughout the loop. */
/* For these specific cases, the rest of the block should be filled with zeroes (already taken care of by using calloc()). */
for(u64 j = 0, k = 0; j < cur_layer_read_size; j += hash_block_size, k++)
{
if (!is_integrity_patch && hash_block_size > (cur_layer_read_size - j)) hash_block_size = (cur_layer_read_size - j);
ncaCalculateLayerHash(parent_layer_block + (k * SHA256_HASH_SIZE), cur_layer_block + j, hash_block_size, use_sha3);
}
} else {
/* Recalculate master hash from the HashData area. */
u8 *master_hash = (!is_integrity_patch ? ctx->header.hash_data.hierarchical_sha256_data.master_hash : ctx->header.hash_data.integrity_meta_info.master_hash);
ncaCalculateLayerHash(master_hash, cur_layer_block, cur_layer_read_size, use_sha3);
}
if (!ctx->skip_hash_layer_crypto || i == layer_count)
{
/* Reencrypt current layer block (if needed). */
cur_layer_patch->data = _ncaGenerateEncryptedFsSectionBlock(ctx, cur_layer_block + cur_layer_read_patch_offset, cur_data_size, cur_layer_offset + cur_data_offset, \
&(cur_layer_patch->size), &(cur_layer_patch->offset));
if (!cur_layer_patch->data)
{
LOG_MSG("Failed to generate encrypted 0x%lX bytes long hierarchical layer #%u data block!", cur_data_size, i - 1);
goto end;
}
} else {
/* Allocate memory for the data block and copy its information. */
cur_layer_patch->data = malloc(cur_data_size);
if (!cur_layer_patch->data)
{
LOG_MSG("Failed to allocate 0x%lX bytes long buffer for hierarchical layer #%u data block!", cur_data_size, i - 1);
goto end;
}
memcpy(cur_layer_patch->data, cur_layer_block + cur_layer_read_patch_offset, cur_data_size);
cur_layer_patch->size = cur_data_size;
cur_layer_patch->offset = (ctx->section_offset + cur_layer_offset + cur_data_offset);
}
/* Free current layer block. */
free(cur_layer_block);
cur_layer_block = NULL;
if (i > 1)
{
/* Free previous layer block (if needed). */
if (cur_data) free(cur_data);
/* Prepare data for the next layer. */
cur_data = parent_layer_block;
cur_data_offset = parent_layer_read_start_offset;
cur_data_size = parent_layer_read_size;
parent_layer_block = NULL;
}
}
/* Recalculate FS header hash. */
sha256CalculateHash(nca_ctx->header.fs_header_hash[ctx->section_num].hash, &(ctx->header), sizeof(NcaFsHeader));
/* Copy content ID. */
memcpy(!is_integrity_patch ? &(hierarchical_sha256_patch->content_id) : &(hierarchical_integrity_patch->content_id), &(nca_ctx->content_id), sizeof(NcmContentId));
/* Set hash region count (if needed). */
if (!is_integrity_patch) hierarchical_sha256_patch->hash_region_count = layer_count;
success = true;
end:
if (cur_layer_block) free(cur_layer_block);
if (parent_layer_block) free(parent_layer_block);
if (!success && out)
{
if (!is_integrity_patch)
{
ncaFreeHierarchicalSha256Patch(hierarchical_sha256_patch);
} else {
ncaFreeHierarchicalIntegrityPatch(hierarchical_integrity_patch);
}
}
return success;
}
static bool ncaWritePatchToMemoryBuffer(NcaContext *ctx, const void *patch, u64 patch_size, u64 patch_offset, void *buf, u64 buf_size, u64 buf_offset)
{
/* Return right away if we're dealing with invalid parameters, or if the buffer data is not part of the range covered by the patch (last two conditions). */
if (!ctx || !patch || !patch_size || (patch_offset + patch_size) > ctx->content_size || (buf_offset + buf_size) <= patch_offset || \
(patch_offset + patch_size) <= buf_offset) return false;
/* Overwrite buffer data using patch data. */
u64 patch_block_offset = (patch_offset < buf_offset ? (buf_offset - patch_offset) : 0);
u64 patch_remaining_size = (patch_size - patch_block_offset);
u64 buf_block_offset = (buf_offset < patch_offset ? (patch_offset - buf_offset) : 0);
u64 buf_remaining_size = (buf_size - buf_block_offset);
u64 buf_block_size = (buf_remaining_size < patch_remaining_size ? buf_remaining_size : patch_remaining_size);
memcpy((u8*)buf + buf_block_offset, (const u8*)patch + patch_block_offset, buf_block_size);
LOG_MSG("Overwrote 0x%lX bytes block at offset 0x%lX from raw %s NCA \"%s\" buffer (size 0x%lX, NCA offset 0x%lX).", buf_block_size, buf_block_offset, titleGetNcmContentTypeName(ctx->content_type), \
ctx->content_id_str, buf_size, buf_offset);
return ((patch_block_offset + buf_block_size) == patch_size);
}
static void *_ncaGenerateEncryptedFsSectionBlock(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, u64 *out_block_size, u64 *out_block_offset)
{
u8 *out = NULL;
bool success = false;
if (!g_ncaCryptoBuffer || !ctx || !ctx->enabled || ctx->has_sparse_layer || !ctx->nca_ctx || ctx->section_num >= NCA_FS_HEADER_COUNT || ctx->section_offset < sizeof(NcaHeader) || \
ctx->hash_type <= NcaHashType_None || ctx->hash_type == NcaHashType_AutoSha3 || ctx->hash_type > NcaHashType_HierarchicalIntegritySha3 || \
ctx->encryption_type == NcaEncryptionType_Auto || ctx->encryption_type == NcaEncryptionType_AesCtrEx || ctx->encryption_type >= NcaEncryptionType_AesCtrExSkipLayerHash || \
ctx->section_type >= NcaFsSectionType_Invalid || !data || !data_size || (data_offset + data_size) > ctx->section_size || !out_block_size || !out_block_offset)
{
LOG_MSG("Invalid NCA FS section header parameters!");
goto end;
}
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 (!*(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) || \
(nca_ctx->format_version != NcaVersion_Nca0 && nca_ctx->format_version != NcaVersion_Nca2 && nca_ctx->format_version != NcaVersion_Nca3) || (content_offset + data_size) > nca_ctx->content_size)
{
LOG_MSG("Invalid NCA header parameters!");
goto end;
}
/* 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 && !(content_offset % NCA_AES_XTS_SECTOR_SIZE) && !(data_size % NCA_AES_XTS_SECTOR_SIZE)) || \
((ctx->encryption_type == NcaEncryptionType_AesCtr || ctx->encryption_type == NcaEncryptionType_AesCtrSkipLayerHash) && !(content_offset % AES_BLOCK_SIZE) && !(data_size % AES_BLOCK_SIZE)))
{
/* Allocate memory. */
out = malloc(data_size);
if (!out)
{
LOG_MSG("Unable to allocate 0x%lX bytes buffer! (aligned).", data_size);
goto end;
}
/* Copy data. */
memcpy(out, data, data_size);
/* Encrypt data. */
if (ctx->encryption_type == NcaEncryptionType_AesXts)
{
sector_num = ((nca_ctx->format_version != NcaVersion_Nca0 ? data_offset : (content_offset - sizeof(NcaHeader))) / 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)
{
LOG_MSG("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 end;
}
} else
if (ctx->encryption_type == NcaEncryptionType_AesCtr || ctx->encryption_type == NcaEncryptionType_AesCtrSkipLayerHash)
{
aes128CtrUpdatePartialCtr(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 end;
}
/* Calculate block offsets and size. */
block_start_offset = ALIGN_DOWN(data_offset, ctx->encryption_type == NcaEncryptionType_AesXts ? NCA_AES_XTS_SECTOR_SIZE : AES_BLOCK_SIZE);
block_end_offset = ALIGN_UP(data_offset + data_size, ctx->encryption_type == NcaEncryptionType_AesXts ? 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)
{
LOG_MSG("Unable to allocate 0x%lX bytes buffer! (unaligned).", block_size);
goto end;
}
/* Read decrypted data using aligned offset and size. */
if (!_ncaReadFsSection(ctx, out, block_size, block_start_offset))
{
LOG_MSG("Failed to read decrypted NCA \"%s\" FS section #%u data block!", nca_ctx->content_id_str, ctx->section_num);
goto end;
}
/* Replace plaintext data. */
memcpy(out + plain_chunk_offset, data, data_size);
/* Reencrypt data. */
if (ctx->encryption_type == NcaEncryptionType_AesXts)
{
sector_num = ((nca_ctx->format_version != NcaVersion_Nca0 ? block_start_offset : (content_offset - sizeof(NcaHeader))) / 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)
{
LOG_MSG("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 end;
}
} else
if (ctx->encryption_type == NcaEncryptionType_AesCtr || ctx->encryption_type == NcaEncryptionType_AesCtrSkipLayerHash)
{
aes128CtrUpdatePartialCtr(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;
end:
if (!success && out)
{
free(out);
out = NULL;
}
return out;
}
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