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Update SabreTools.Models
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@mnadareski
mnadareski committed Aug 8, 2024
1 parent 6ec5c69 commit 0aa9463
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Showing 4 changed files with 54 additions and 65 deletions.
2 changes: 1 addition & 1 deletion NDecrypt.N3DS/NDecrypt.N3DS.csproj
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Original file line number Diff line number Diff line change
Expand Up @@ -40,7 +40,7 @@
</ItemGroup>

<ItemGroup>
<PackageReference Include="SabreTools.Models" Version="1.4.8" />
<PackageReference Include="SabreTools.Models" Version="1.4.9" />
</ItemGroup>

</Project>
20 changes: 8 additions & 12 deletions NDecrypt.N3DS/Serializer.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -24,40 +24,36 @@ internal static class Serializer
/// <param name="reader">BinaryReader representing the input stream</param>
/// <param name="development">True if development cart, false otherwise</param>
/// <returns>N3DS cart image object, null on error</returns>
public static (Cart?, NCCHHeader?) ReadCart(BinaryReader reader, bool development)
public static Cart? ReadCart(BinaryReader reader, bool development)
{
var cart = new Cart();
NCCHHeader? backupHeader = null;

try
{
cart.Header = ReadNCSDHeader(reader);
if (cart.Header == null)
return (null, null);
return null;

if (cart.Header.PartitionsFSType == FilesystemType.Normal
|| cart.Header.PartitionsFSType == FilesystemType.None)
{
cart.CardInfoHeader = ReadCardInfoHeader(reader);
if (cart.CardInfoHeader == null)
return (null, null);

// TODO: Remove when InitialData is read correctly
backupHeader = ReadNCCHHeader(reader, readSignature: false);
return null;

if (development)
{
cart.DevelopmentCardInfoHeader = ReadDevelopmentCardInfoHeader(reader);
if (cart.DevelopmentCardInfoHeader == null)
return (null, null);
return null;
}
}

return (cart, backupHeader);
return cart;
}
catch
{
return (null, null); ;
return null;
}
}

Expand Down Expand Up @@ -236,7 +232,7 @@ public static (Cart?, NCCHHeader?) ReadCart(BinaryReader reader, bool developmen
header.TitleVersion = reader.ReadUInt16();
header.CardRevision = reader.ReadUInt16();
header.Reserved4 = reader.ReadBytes(0xCD6);
_ = ReadInitialData(reader);
header.InitialData = ReadInitialData(reader);

return header;
}
Expand Down Expand Up @@ -424,7 +420,7 @@ public static (Cart?, NCCHHeader?) ReadCart(BinaryReader reader, bool developmen
id.CardSeedAESMAC = reader.ReadBytes(0x10);
id.CardSeedNonce = reader.ReadBytes(0x0C);
id.Reserved = reader.ReadBytes(0xC4);
// TODO: Read backup header here instead of separately
id.BackupHeader = ReadNCCHHeader(reader, readSignature: false);

return id;
}
Expand Down
95 changes: 44 additions & 51 deletions NDecrypt.N3DS/ThreeDSTool.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -72,15 +72,15 @@ public bool ProcessFile()
using var writer = new BinaryWriter(File.Open(filename, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite));

// Deserialize the cart information
(var cart, var backupHeader) = Serializer.ReadCart(reader, decryptArgs.Development);
if (cart?.Header == null)
var cart = Serializer.ReadCart(reader, decryptArgs.Development);
if (cart?.Header == null || cart?.CardInfoHeader?.InitialData?.BackupHeader == null)
{
Console.WriteLine("Error: Not a 3DS cart image!");
return false;
}

// Process all 8 NCCH partitions
ProcessAllPartitions(cart.Header, backupHeader, reader, writer);
ProcessAllPartitions(cart, reader, writer);

return true;
}
Expand All @@ -95,20 +95,19 @@ public bool ProcessFile()
/// <summary>
/// Process all partitions in the partition table of an NCSD header
/// </summary>
/// <param name="ncsdHeader">NCSD header representing the 3DS file</param>
/// <param name="backupHeader">Backup NCCH header</param>
/// <param name="cart">Cart representing the 3DS file</param>
/// <param name="reader">BinaryReader representing the input stream</param>
/// <param name="writer">BinaryWriter representing the output stream</param>
private void ProcessAllPartitions(NCSDHeader ncsdHeader, NCCHHeader? backupHeader, BinaryReader reader, BinaryWriter writer)
private void ProcessAllPartitions(Cart cart, BinaryReader reader, BinaryWriter writer)
{
// Iterate over all 8 NCCH partitions
for (int p = 0; p < 8; p++)
{
(int partitionIndex, var ncchHeader, var tableEntry) = GetPartitionHeader(ncsdHeader, reader, p);
(int partitionIndex, var ncchHeader, var tableEntry) = GetPartitionHeader(cart.Header, reader, p);
if (partitionIndex < 0 || ncchHeader == null || tableEntry == null)
continue;

ProcessPartition(ncsdHeader, partitionIndex, ncchHeader, tableEntry, backupHeader, reader, writer);
ProcessPartition(cart, partitionIndex, ncchHeader, tableEntry, reader, writer);
}
}

Expand All @@ -119,10 +118,10 @@ private void ProcessAllPartitions(NCSDHeader ncsdHeader, NCCHHeader? backupHeade
/// <param name="reader">BinaryReader representing the input stream</param>
/// <param name="partitionNumber">Partition number to attempt to retrieve</param>
/// <returns>NCCH header for the partition requested, null on error</returns>
private static (int, NCCHHeader?, PartitionTableEntry?) GetPartitionHeader(NCSDHeader ncsdHeader, BinaryReader reader, int partitionNumber)
private static (int, NCCHHeader?, PartitionTableEntry?) GetPartitionHeader(NCSDHeader? ncsdHeader, BinaryReader reader, int partitionNumber)
{
// Check the partitions table
if (ncsdHeader.PartitionsTable == null)
if (ncsdHeader?.PartitionsTable == null)
{
Console.WriteLine("Invalid partitions table... Skipping...");
return (-1, null, null);
Expand Down Expand Up @@ -154,18 +153,16 @@ private static (int, NCCHHeader?, PartitionTableEntry?) GetPartitionHeader(NCSDH
/// <summary>
/// Process a single partition
/// </summary>
/// <param name="ncsdHeader">NCSD header representing the 3DS file</param>
/// <param name="cart">Cart representing the 3DS file</param>
/// <param name="partitionIndex">Index of the partition</param>
/// <param name="ncchHeader">NCCH header representing the partition</param>
/// <param name="tableEntry">PartitionTableEntry header representing the partition</param>
/// <param name="backupHeader">Backup NCCH header</param>
/// <param name="reader">BinaryReader representing the input stream</param>
/// <param name="writer">BinaryWriter representing the output stream</param>
private void ProcessPartition(NCSDHeader ncsdHeader,
private void ProcessPartition(Cart cart,
int partitionIndex,
NCCHHeader ncchHeader,
PartitionTableEntry tableEntry,
NCCHHeader? backupHeader,
BinaryReader reader,
BinaryWriter writer)
{
Expand All @@ -182,37 +179,37 @@ private void ProcessPartition(NCSDHeader ncsdHeader,
}

// Determine the Keys to be used
SetEncryptionKeys(partitionIndex, ncchHeader, backupHeader);
SetEncryptionKeys(cart, partitionIndex, ncchHeader);

// Process the extended header
ProcessExtendedHeader(ncsdHeader, partitionIndex, ncchHeader, tableEntry, reader, writer);
ProcessExtendedHeader(cart.Header!, partitionIndex, ncchHeader, tableEntry, reader, writer);

// If we're encrypting, encrypt the filesystems and update the flags
if (decryptArgs.Encrypt)
{
EncryptExeFS(ncsdHeader, partitionIndex, ncchHeader, tableEntry, backupHeader, reader, writer);
EncryptRomFS(ncsdHeader, partitionIndex, ncchHeader, tableEntry, backupHeader, reader, writer);
UpdateEncryptCryptoAndMasks(ncsdHeader, partitionIndex, ncchHeader, tableEntry, backupHeader, writer);
EncryptExeFS(cart, partitionIndex, ncchHeader, tableEntry, reader, writer);
EncryptRomFS(cart, partitionIndex, ncchHeader, tableEntry, reader, writer);
UpdateEncryptCryptoAndMasks(cart, partitionIndex, ncchHeader, tableEntry, writer);
}

// If we're decrypting, decrypt the filesystems and update the flags
else
{
DecryptExeFS(ncsdHeader, partitionIndex, ncchHeader, tableEntry, reader, writer);
DecryptRomFS(ncsdHeader, partitionIndex, ncchHeader, tableEntry, reader, writer);
UpdateDecryptCryptoAndMasks(ncsdHeader, ncchHeader, tableEntry, writer);
DecryptExeFS(cart.Header!, partitionIndex, ncchHeader, tableEntry, reader, writer);
DecryptRomFS(cart.Header!, partitionIndex, ncchHeader, tableEntry, reader, writer);
UpdateDecryptCryptoAndMasks(cart.Header!, ncchHeader, tableEntry, writer);
}
}

/// <summary>
/// Determine the set of keys to be used for encryption or decryption
/// </summary>
/// <param name="cart">Cart representing the 3DS file</param>
/// <param name="partitionIndex">Index of the partition</param>
/// <param name="ncchHeader">NCCH header representing the partition</param>
/// <param name="backupHeader">Backup NCCH header</param>
private void SetEncryptionKeys(int partitionIndex,
NCCHHeader ncchHeader,
NCCHHeader? backupHeader)
private void SetEncryptionKeys(Cart cart,
int partitionIndex,
NCCHHeader ncchHeader)
{
KeyX[partitionIndex] = 0;
KeyX2C[partitionIndex] = decryptArgs.Development ? decryptArgs.DevKeyX0x2C : decryptArgs.KeyX0x2C;
Expand All @@ -231,8 +228,8 @@ private void SetEncryptionKeys(int partitionIndex,
CryptoMethod method;
if (decryptArgs.Encrypt)
{
masks = backupHeader!.Flags!.BitMasks;
method = backupHeader.Flags.CryptoMethod;
masks = cart.CardInfoHeader!.InitialData!.BackupHeader!.Flags!.BitMasks;
method = cart.CardInfoHeader.InitialData.BackupHeader.Flags.CryptoMethod;
}
else
{
Expand Down Expand Up @@ -585,18 +582,16 @@ private void UpdateDecryptCryptoAndMasks(NCSDHeader ncsdHeader,
/// <summary>
/// Encrypt the ExeFS, if it exists
/// </summary>
/// <param name="ncsdHeader">NCSD header representing the 3DS file</param>
/// <param name="cart">Cart representing the 3DS file</param>
/// <param name="partitionIndex">Index of the partition</param>
/// <param name="ncchHeader">NCCH header representing the partition</param>
/// <param name="tableEntry">PartitionTableEntry header representing the partition</param>
/// <param name="backupHeader">Backup NCCH header</param>
/// <param name="reader">BinaryReader representing the input stream</param>
/// <param name="writer">BinaryWriter representing the output stream</param>
private void EncryptExeFS(NCSDHeader ncsdHeader,
private void EncryptExeFS(Cart cart,
int partitionIndex,
NCCHHeader ncchHeader,
PartitionTableEntry tableEntry,
NCCHHeader? backupHeader,
BinaryReader reader,
BinaryWriter writer)
{
Expand All @@ -608,32 +603,31 @@ private void EncryptExeFS(NCSDHeader ncsdHeader,
}

// For all but the original crypto method, process each of the files in the table
if (backupHeader!.Flags!.CryptoMethod != CryptoMethod.Original)
ProcessExeFSFileEntries(ncsdHeader, partitionIndex, ncchHeader, tableEntry, reader, writer);
if (cart.CardInfoHeader!.InitialData!.BackupHeader!.Flags!.CryptoMethod != CryptoMethod.Original)
ProcessExeFSFileEntries(cart.Header!, partitionIndex, ncchHeader, tableEntry, reader, writer);

// Encrypt the filename table
ProcessExeFSFilenameTable(ncsdHeader, partitionIndex, ncchHeader, tableEntry, reader, writer);
ProcessExeFSFilenameTable(cart.Header!, partitionIndex, ncchHeader, tableEntry, reader, writer);

// Encrypt the rest of the ExeFS
ProcessExeFS(ncsdHeader, partitionIndex, ncchHeader, tableEntry, reader, writer);
ProcessExeFS(cart.Header!, partitionIndex, ncchHeader, tableEntry, reader, writer);
}

/// <summary>
/// Encrypt the RomFS, if it exists
/// </summary>
/// <param name="ncsdHeader">NCSD header representing the 3DS file</param>
/// <param name="cart">Cart representing the 3DS file</param>
/// <param name="partitionIndex">Index of the partition</param>
/// <param name="ncchHeader">NCCH header representing the partition</param>
/// <param name="tableEntry">PartitionTableEntry header representing the partition</param>
/// <param name="backupHeader">Backup NCCH header</param>
/// <param name="reader">BinaryReader representing the input stream</param>
/// <param name="writer">BinaryWriter representing the output stream</param>
/// TODO: See how much can be extracted into a common method with Decrypt
private void EncryptRomFS(NCSDHeader ncsdHeader,
private void EncryptRomFS(Cart cart,
int partitionIndex,
NCCHHeader ncchHeader,
PartitionTableEntry tableEntry,
NCCHHeader? backupHeader,
BinaryReader reader,
BinaryWriter writer)
{
Expand All @@ -644,13 +638,13 @@ private void EncryptRomFS(NCSDHeader ncsdHeader,
return;
}

long romfsSizeM = (int)((long)(ncchHeader.RomFSSizeInMediaUnits * ncsdHeader.MediaUnitSize()) / (1024 * 1024));
int romfsSizeB = (int)((long)(ncchHeader.RomFSSizeInMediaUnits * ncsdHeader.MediaUnitSize()) % (1024 * 1024));
long romfsSizeM = (int)((long)(ncchHeader.RomFSSizeInMediaUnits * cart.Header.MediaUnitSize()) / (1024 * 1024));
int romfsSizeB = (int)((long)(ncchHeader.RomFSSizeInMediaUnits * cart.Header.MediaUnitSize()) % (1024 * 1024));

// Encrypting RomFS for partitions 1 and up always use Key0x2C
if (partitionIndex > 0)
{
if (backupHeader!.Flags?.BitMasks.HasFlag(BitMasks.FixedCryptoKey) == true) // except if using zero-key
if (cart.CardInfoHeader!.InitialData!.BackupHeader!.Flags?.BitMasks.HasFlag(BitMasks.FixedCryptoKey) == true) // except if using zero-key
{
NormalKey[partitionIndex] = 0x00;
}
Expand All @@ -663,8 +657,8 @@ private void EncryptRomFS(NCSDHeader ncsdHeader,

var cipher = CreateAESCipher(NormalKey[partitionIndex], ncchHeader.RomFSIV(), decryptArgs.Encrypt);

reader.BaseStream.Seek((tableEntry.Offset + ncchHeader.RomFSOffsetInMediaUnits) * ncsdHeader.MediaUnitSize(), SeekOrigin.Begin);
writer.BaseStream.Seek((tableEntry.Offset + ncchHeader.RomFSOffsetInMediaUnits) * ncsdHeader.MediaUnitSize(), SeekOrigin.Begin);
reader.BaseStream.Seek((tableEntry.Offset + ncchHeader.RomFSOffsetInMediaUnits) * cart.Header.MediaUnitSize(), SeekOrigin.Begin);
writer.BaseStream.Seek((tableEntry.Offset + ncchHeader.RomFSOffsetInMediaUnits) * cart.Header.MediaUnitSize(), SeekOrigin.Begin);
if (romfsSizeM > 0)
{
for (int i = 0; i < romfsSizeM; i++)
Expand All @@ -690,37 +684,36 @@ private void EncryptRomFS(NCSDHeader ncsdHeader,
/// <summary>
/// Update the CryptoMethod and BitMasks for the encrypted partition
/// </summary>
/// <param name="ncsdHeader">NCSD header representing the 3DS file</param>
/// <param name="cart">Cart representing the 3DS file</param>
/// <param name="partitionIndex">Index of the partition</param>
/// <param name="ncchHeader">NCCH header representing the partition</param>
/// <param name="tableEntry">PartitionTableEntry header representing the partition</param>
/// <param name="backupHeader">Backup NCCH header</param>
/// <param name="writer">BinaryWriter representing the output stream</param>
private static void UpdateEncryptCryptoAndMasks(NCSDHeader ncsdHeader,
private static void UpdateEncryptCryptoAndMasks(Cart cart,
int partitionIndex,
NCCHHeader ncchHeader,
PartitionTableEntry tableEntry,
NCCHHeader? backupHeader,
BinaryWriter writer)
{
// Write the new CryptoMethod
writer.BaseStream.Seek((tableEntry.Offset * ncsdHeader.MediaUnitSize()) + 0x18B, SeekOrigin.Begin);
writer.BaseStream.Seek((tableEntry.Offset * cart.Header.MediaUnitSize()) + 0x18B, SeekOrigin.Begin);

// For partitions 1 and up, set crypto-method to 0x00
if (partitionIndex > 0)
writer.Write((byte)CryptoMethod.Original);

// If partition 0, restore crypto-method from backup flags
else
writer.Write((byte)backupHeader!.Flags!.CryptoMethod);
writer.Write((byte)cart.CardInfoHeader!.InitialData!.BackupHeader!.Flags!.CryptoMethod);

writer.Flush();

// Write the new BitMasks flag
writer.BaseStream.Seek((tableEntry.Offset * ncsdHeader.MediaUnitSize()) + 0x18F, SeekOrigin.Begin);
writer.BaseStream.Seek((tableEntry.Offset * cart.Header.MediaUnitSize()) + 0x18F, SeekOrigin.Begin);
BitMasks flag = ncchHeader.Flags!.BitMasks;
flag &= (BitMasks.FixedCryptoKey | BitMasks.NewKeyYGenerator | BitMasks.NoCrypto) ^ (BitMasks)0xFF;
flag |= (BitMasks.FixedCryptoKey | BitMasks.NewKeyYGenerator) & backupHeader!.Flags!.BitMasks;
flag |= (BitMasks.FixedCryptoKey | BitMasks.NewKeyYGenerator) & cart.CardInfoHeader!.InitialData!.BackupHeader!.Flags!.BitMasks;
writer.Write((byte)flag);
writer.Flush();
}
Expand Down
2 changes: 1 addition & 1 deletion NDecrypt.Nitro/NDecrypt.Nitro.csproj
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Original file line number Diff line number Diff line change
Expand Up @@ -40,7 +40,7 @@
</ItemGroup>

<ItemGroup>
<PackageReference Include="SabreTools.Models" Version="1.4.8" />
<PackageReference Include="SabreTools.Models" Version="1.4.9" />
</ItemGroup>

</Project>

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