/* * nca.c * * Copyright (c) 2020, DarkMatterCore . * * 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 and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * nxdumptool 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 . */ #include "utils.h" #include "nca.h" #include "keys.h" #include "aes.h" #include "rsa.h" #include "gamecard.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 bool ncaDecryptHeader(NcaContext *ctx); static bool ncaDecryptKeyArea(NcaContext *ctx); NX_INLINE bool ncaIsVersion0KeyAreaEncrypted(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); static bool _ncaReadAesCtrExStorageFromBktrSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset, u32 ctr_val, bool lock); static void *_ncaGenerateEncryptedFsSectionBlock(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, u64 *out_block_size, u64 *out_block_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 (ncaIsVersion0KeyAreaEncrypted(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 - NCA_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 NcmContentInfo *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->content_type > NcmContentType_DeltaFragment) { LOGFILE("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)); out->content_type = content_info->content_type; out->id_offset = content_info->id_offset; ncaConvertNcmContentSizeToU64(content_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; } 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)) { /* Copy decrypted titlekey. */ memcpy(out->titlekey, tik->dec_titlekey, 0x10); out->titlekey_retrieved = true; } else { LOGFILE("Error retrieving ticket for NCA \"%s\"!", out->content_id_str); } } else { /* Decrypt key area. */ if (out->format_version != NcaVersion_Nca0 && !ncaDecryptKeyArea(out)) { LOGFILE("Error decrypting NCA key area!"); return false; } } /* Return right away if the NCA uses titlekey crypto and the titlekey couldn't be retrieved. */ if (out->rights_id_available && !out->titlekey_retrieved) return true; /* Parse sections. */ for(u8 i = 0; i < NCA_FS_HEADER_COUNT; i++) { /* Skip NCA section if it's not enabled in the FS entries. */ 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]); /* Determine encryption type. */ out->fs_contexts[i].encryption_type = (out->format_version == NcaVersion_Nca0 ? NcaEncryptionType_AesXts : 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_AesCtrEx) { memset(&(out->fs_contexts[i]), 0, sizeof(NcaFsSectionContext)); 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) { memset(&(out->fs_contexts[i]), 0, sizeof(NcaFsSectionContext)); continue; } /* Initialize crypto related fields. */ if (out->fs_contexts[i].encryption_type > NcaEncryptionType_None && out->fs_contexts[i].encryption_type <= NcaEncryptionType_AesCtrEx) { /* 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) { /* 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); } } } /* Enable FS context if we got up to this point. */ out->fs_contexts[i].enabled = 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); } bool ncaReadAesCtrExStorageFromBktrSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset, u32 ctr_val) { return _ncaReadAesCtrExStorageFromBktrSection(ctx, out, read_size, offset, ctr_val, true); } void *ncaGenerateEncryptedFsSectionBlock(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, u64 *out_block_size, u64 *out_block_offset) { return _ncaGenerateEncryptedFsSectionBlock(ctx, data, data_size, data_offset, out_block_size, out_block_offset, true); } bool ncaGenerateHierarchicalSha256Patch(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, NcaHierarchicalSha256Patch *out) { mutexLock(&g_ncaCryptoBufferMutex); NcaContext *nca_ctx = NULL; u64 hash_block_size = 0; u64 hash_data_layer_offset = 0, hash_data_layer_size = 0; u64 hash_target_layer_offset = 0, hash_target_layer_size = 0; u8 *hash_data_layer = NULL, *hash_target_block = NULL; bool success = false; if (!ctx || !ctx->enabled || !(nca_ctx = (NcaContext*)ctx->nca_ctx) || !ctx->header || ctx->header->hash_type != NcaHashType_HierarchicalSha256 || \ ctx->header->encryption_type == NcaEncryptionType_AesCtrEx || !data || !data_size || !(hash_block_size = ctx->header->hash_info.hierarchical_sha256.hash_block_size) || \ !(hash_data_layer_size = ctx->header->hash_info.hierarchical_sha256.hash_data_layer_info.size) || \ !(hash_target_layer_size = ctx->header->hash_info.hierarchical_sha256.hash_target_layer_info.size) || data_offset >= hash_target_layer_size || \ (data_offset + data_size) > hash_target_layer_size || !out) { LOGFILE("Invalid parameters!"); goto end; } /* Calculate required offsets and sizes. */ hash_data_layer_offset = ctx->header->hash_info.hierarchical_sha256.hash_data_layer_info.offset; hash_target_layer_offset = ctx->header->hash_info.hierarchical_sha256.hash_target_layer_info.offset; u64 hash_data_start_offset = ((data_offset / hash_block_size) * SHA256_HASH_SIZE); u64 hash_data_end_offset = (((data_offset + data_size) / hash_block_size) * SHA256_HASH_SIZE); u64 hash_data_size = (hash_data_end_offset != hash_data_start_offset ? (hash_data_end_offset - hash_data_start_offset) : SHA256_HASH_SIZE); u64 hash_target_start_offset = (hash_target_layer_offset + ALIGN_DOWN(data_offset, hash_block_size)); u64 hash_target_end_offset = (hash_target_layer_offset + ALIGN_UP(data_offset + data_size, hash_block_size)); if (hash_target_end_offset > (hash_target_layer_offset + hash_target_layer_size)) hash_target_end_offset = (hash_target_layer_offset + hash_target_layer_size); u64 hash_target_size = (hash_target_end_offset - hash_target_start_offset); u64 hash_target_data_offset = (data_offset - ALIGN_DOWN(data_offset, hash_block_size)); /* Allocate memory for the full hash data layer. */ hash_data_layer = malloc(hash_data_layer_size); if (!hash_data_layer) { LOGFILE("Unable to allocate 0x%lX bytes buffer for the full HierarchicalSha256 hash data layer!", hash_data_layer_size); goto end; } /* Read full hash data layer. */ if (!_ncaReadFsSection(ctx, hash_data_layer, hash_data_layer_size, hash_data_layer_offset, false)) { LOGFILE("Failed to read full HierarchicalSha256 hash data layer!"); goto end; } /* Allocate memory for the modified hash target layer block. */ hash_target_block = malloc(hash_target_size); if (!hash_target_block) { LOGFILE("Unable to allocate 0x%lX bytes buffer for the modified HierarchicalSha256 hash target layer block!", hash_target_size); goto end; } /* Read hash target layer block. */ if (!_ncaReadFsSection(ctx, hash_target_block, hash_target_size, hash_target_start_offset, false)) { LOGFILE("Failed to read HierarchicalSha256 hash target layer block!"); goto end; } /* Replace data. */ memcpy(hash_target_block + hash_target_data_offset, data, data_size); /* Recalculate hashes. */ for(u64 i = 0, j = 0; i < hash_target_size; i += hash_block_size, j++) { if (hash_block_size > (hash_target_size - i)) hash_block_size = (hash_target_size - i); sha256CalculateHash(hash_data_layer + hash_data_start_offset + (j * SHA256_HASH_SIZE), hash_target_block + i, hash_block_size); } /* Reencrypt modified hash data layer block. */ out->hash_data_layer_patch.data = _ncaGenerateEncryptedFsSectionBlock(ctx, hash_data_layer + hash_data_start_offset, hash_data_size, hash_data_layer_offset + hash_data_start_offset, \ &(out->hash_data_layer_patch.size), &(out->hash_data_layer_patch.offset), false); if (!out->hash_data_layer_patch.data) { LOGFILE("Failed to generate encrypted HierarchicalSha256 hash data layer block!"); goto end; } /* Reencrypt hash target layer block. */ out->hash_target_layer_patch.data = _ncaGenerateEncryptedFsSectionBlock(ctx, hash_target_block + hash_target_data_offset, data_size, hash_target_layer_offset + data_offset, \ &(out->hash_target_layer_patch.size), &(out->hash_target_layer_patch.offset), false); if (!out->hash_target_layer_patch.data) { LOGFILE("Failed to generate encrypted HierarchicalSha256 hash target layer block!"); goto end; } /* Recalculate master hash from hash info block. */ sha256CalculateHash(ctx->header->hash_info.hierarchical_sha256.master_hash, hash_data_layer, hash_data_layer_size); /* Recalculate FS header hash. */ sha256CalculateHash(nca_ctx->header.fs_hashes[ctx->section_num].hash, ctx->header, sizeof(NcaFsHeader)); /* Enable the 'dirty_header' flag. */ nca_ctx->dirty_header = true; success = true; end: if (hash_target_block) free(hash_target_block); if (hash_data_layer) free(hash_data_layer); if (!success) ncaFreeHierarchicalSha256Patch(out); mutexUnlock(&g_ncaCryptoBufferMutex); return success; } bool ncaGenerateHierarchicalIntegrityPatch(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, NcaHierarchicalIntegrityPatch *out) { mutexLock(&g_ncaCryptoBufferMutex); NcaContext *nca_ctx = NULL; bool success = false; u8 *cur_data = NULL; u64 cur_data_offset = data_offset; u64 cur_data_size = data_size; u8 *hash_data_block = NULL, *hash_target_block = NULL; if (!ctx || !ctx->enabled || !(nca_ctx = (NcaContext*)ctx->nca_ctx) || !ctx->header || ctx->header->hash_type != NcaHashType_HierarchicalIntegrity || \ ctx->header->encryption_type == NcaEncryptionType_AesCtrEx || !data || !data_size || !out || data_offset >= ctx->header->hash_info.hierarchical_integrity.hash_target_layer_info.size || \ (data_offset + data_size) > ctx->header->hash_info.hierarchical_integrity.hash_target_layer_info.size) { LOGFILE("Invalid parameters!"); goto end; } /* Process each IVFC layer. */ for(u8 i = (NCA_IVFC_HASH_DATA_LAYER_COUNT + 1); i > 0; i--) { NcaHierarchicalIntegrityLayerInfo *cur_layer_info = (i > NCA_IVFC_HASH_DATA_LAYER_COUNT ? &(ctx->header->hash_info.hierarchical_integrity.hash_target_layer_info) : \ &(ctx->header->hash_info.hierarchical_integrity.hash_data_layer_info[i - 1])); NcaHierarchicalIntegrityLayerInfo *parent_layer_info = (i > 1 ? &(ctx->header->hash_info.hierarchical_integrity.hash_data_layer_info[i - 2]) : NULL); NcaHashInfoLayerPatch *cur_layer_patch = (i > NCA_IVFC_HASH_DATA_LAYER_COUNT ? &(out->hash_target_layer_patch) : &(out->hash_data_layer_patch[i - 1])); if (!cur_layer_info->size || !cur_layer_info->block_size || (parent_layer_info && (!parent_layer_info->size || !parent_layer_info->block_size))) { LOGFILE("Invalid HierarchicalIntegrity parent/child layer!"); goto end; } /* Calculate required offsets and sizes. */ u64 hash_block_size = NCA_IVFC_BLOCK_SIZE(cur_layer_info->block_size); u64 hash_data_layer_offset = 0; u64 hash_data_start_offset = 0, hash_data_end_offset = 0, hash_data_size = 0; u64 hash_target_layer_offset = cur_layer_info->offset, hash_target_layer_size = cur_layer_info->size; u64 hash_target_start_offset = 0, hash_target_end_offset = 0, hash_target_size = 0, hash_target_data_offset = 0; if (parent_layer_info) { /* HierarchicalIntegrity layer from L1 to L5. */ hash_data_layer_offset = parent_layer_info->offset; hash_data_start_offset = ((cur_data_offset / hash_block_size) * SHA256_HASH_SIZE); hash_data_end_offset = (((cur_data_offset + cur_data_size) / hash_block_size) * SHA256_HASH_SIZE); hash_data_size = (hash_data_end_offset != hash_data_start_offset ? (hash_data_end_offset - hash_data_start_offset) : SHA256_HASH_SIZE); hash_target_start_offset = (hash_target_layer_offset + ALIGN_DOWN(cur_data_offset, hash_block_size)); hash_target_end_offset = (hash_target_layer_offset + ALIGN_UP(cur_data_offset + cur_data_size, hash_block_size)); hash_target_size = (hash_target_end_offset - hash_target_start_offset); } else { /* HierarchicalIntegrity master layer. */ /* The master hash is calculated over the whole layer and saved to the NCA FS header. */ hash_target_start_offset = hash_target_layer_offset; hash_target_end_offset = (hash_target_layer_offset + hash_target_layer_size); hash_target_size = hash_target_layer_size; } hash_target_data_offset = (cur_data_offset - ALIGN_DOWN(cur_data_offset, hash_block_size)); /* Allocate memory for our hash target layer block. */ hash_target_block = calloc(hash_target_size, sizeof(u8)); if (!hash_target_block) { LOGFILE("Unable to allocate 0x%lX bytes for the HierarchicalIntegrity hash target layer block!"); goto end; } /* Adjust hash target layer end offset and size if needed to avoid read errors. */ if (hash_target_end_offset > (hash_target_layer_offset + hash_target_layer_size)) { hash_target_end_offset = (hash_target_layer_offset + hash_target_layer_size); hash_target_size = (hash_target_end_offset - hash_target_start_offset); } /* Read hash target layer block. */ if (!_ncaReadFsSection(ctx, hash_target_block, hash_target_size, hash_target_start_offset, false)) { LOGFILE("Failed to read HierarchicalIntegrity hash target layer block!"); goto end; } /* Replace hash target layer block data. */ memcpy(hash_target_block + hash_target_data_offset, (i > NCA_IVFC_HASH_DATA_LAYER_COUNT ? data : cur_data), cur_data_size); if (parent_layer_info) { /* Allocate memory for our hash data layer block. */ hash_data_block = calloc(hash_data_size, sizeof(u8)); if (!hash_data_block) { LOGFILE("Unable to allocate 0x%lX bytes for the HierarchicalIntegrity hash data layer block!"); goto end; } /* Read hash target layer block. */ if (!_ncaReadFsSection(ctx, hash_data_block, hash_data_size, hash_data_layer_offset + hash_data_start_offset, false)) { LOGFILE("Failed to read HierarchicalIntegrity hash data layer block!"); goto end; } /* Recalculate hashes. */ /* Size isn't truncated for blocks smaller than the hash block size, unlike HierarchicalSha256, 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 i = 0, j = 0; i < hash_target_size; i += hash_block_size, j++) sha256CalculateHash(hash_data_block + (j * SHA256_HASH_SIZE), hash_target_block + i, hash_block_size); } else { /* Recalculate master hash from hash info block. */ sha256CalculateHash(ctx->header->hash_info.hierarchical_integrity.master_hash, hash_target_block, hash_target_size); } /* Reencrypt hash target layer block. */ cur_layer_patch->data = _ncaGenerateEncryptedFsSectionBlock(ctx, hash_target_block + hash_target_data_offset, cur_data_size, hash_target_layer_offset + cur_data_offset, \ &(cur_layer_patch->size), &(cur_layer_patch->offset), false); if (!cur_layer_patch->data) { LOGFILE("Failed to generate encrypted HierarchicalIntegrity hash target layer block!"); goto end; } /* Free hash target layer block. */ free(hash_target_block); hash_target_block = NULL; if (parent_layer_info) { /* Free previous layer data if necessary. */ if (cur_data) free(cur_data); /* Prepare data for the next target layer. */ cur_data = hash_data_block; cur_data_offset = hash_data_start_offset; cur_data_size = hash_data_size; hash_data_block = NULL; } } /* Recalculate FS header hash. */ sha256CalculateHash(nca_ctx->header.fs_hashes[ctx->section_num].hash, ctx->header, sizeof(NcaFsHeader)); /* Enable the 'dirty_header' flag. */ nca_ctx->dirty_header = true; success = true; end: if (hash_data_block) free(hash_data_block); if (hash_target_block) free(hash_target_block); if (cur_data) free(cur_data); if (!success) ncaFreeHierarchicalIntegrityPatch(out); mutexUnlock(&g_ncaCryptoBufferMutex); return success; } 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 (ncaIsVersion0KeyAreaEncrypted(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 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_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->enabled || !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_AesCtrEx || !ctx->header || !out || !read_size || \ offset >= ctx->section_size || (offset + read_size) > ctx->section_size) { LOGFILE("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 + 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 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_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 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 = ((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 end; } } 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 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)) { 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 end; } /* Decrypt data. */ if (ctx->encryption_type == NcaEncryptionType_AesXts) { 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 end; } } 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); end: if (lock) mutexUnlock(&g_ncaCryptoBufferMutex); return ret; } static bool _ncaReadAesCtrExStorageFromBktrSection(NcaFsSectionContext *ctx, void *out, u64 read_size, u64 offset, u32 ctr_val, bool lock) { if (lock) mutexLock(&g_ncaCryptoBufferMutex); bool ret = false; if (!g_ncaCryptoBuffer || !ctx || !ctx->enabled || !ctx->nca_ctx || ctx->section_num >= NCA_FS_HEADER_COUNT || ctx->section_offset < NCA_FULL_HEADER_LENGTH || \ ctx->section_type != NcaFsSectionType_PatchRomFs || ctx->encryption_type != NcaEncryptionType_AesCtrEx || !ctx->header || !out || !read_size || offset >= ctx->section_size || \ (offset + read_size) > ctx->section_size) { LOGFILE("Invalid NCA FS section header parameters!"); goto end; } 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 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)) { 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 end; } /* Decrypt data */ ncaUpdateAesCtrExIv(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)) { 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 end; } /* Decrypt data. */ ncaUpdateAesCtrExIv(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, false) : true); end: if (lock) mutexUnlock(&g_ncaCryptoBufferMutex); return ret; } static void *_ncaGenerateEncryptedFsSectionBlock(NcaFsSectionContext *ctx, const void *data, u64 data_size, u64 data_offset, u64 *out_block_size, u64 *out_block_offset, bool lock) { if (lock) mutexLock(&g_ncaCryptoBufferMutex); u8 *out = NULL; bool success = false; if (!g_ncaCryptoBuffer || !ctx || !ctx->enabled || !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_AesCtrEx || !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 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 (!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 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 && !(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 end; } /* Copy data. */ memcpy(out, data, data_size); /* Encrypt data. */ if (ctx->encryption_type == NcaEncryptionType_AesXts) { 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 end; } } else if (ctx->encryption_type == NcaEncryptionType_AesCtr) { 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 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) { LOGFILE("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, false)) { LOGFILE("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 = ((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 end; } } else if (ctx->encryption_type == NcaEncryptionType_AesCtr) { 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; end: if (!success && out) { free(out); out = NULL; } if (lock) mutexUnlock(&g_ncaCryptoBufferMutex); return out; }