mirror of
https://github.com/SabreTools/NDecrypt.git
synced 2026-02-18 05:56:07 +00:00
837 lines
34 KiB
C#
837 lines
34 KiB
C#
using System;
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using System.IO;
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using SabreTools.IO.Extensions;
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using SabreTools.Models.N3DS;
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using static NDecrypt.Core.CommonOperations;
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using N3DSDeserializer = SabreTools.Serialization.Deserializers.N3DS;
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namespace NDecrypt.Core
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{
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public class ThreeDSTool : ITool
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{
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/// <summary>
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/// Decryption args to use while processing
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/// </summary>
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private readonly DecryptArgs _decryptArgs;
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/// <summary>
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/// Indicates if development images are expected
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/// </summary>
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private readonly bool _development;
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/// <summary>
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/// Set of all partition keys
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/// </summary>
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private readonly PartitionKeys[] KeysMap = new PartitionKeys[8];
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public ThreeDSTool(bool development, DecryptArgs decryptArgs)
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{
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_development = development;
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_decryptArgs = decryptArgs;
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}
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/// <inheritdoc/>
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public bool EncryptFile(string filename, bool force)
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{
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// Ensure the constants are all set
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if (_decryptArgs.IsReady != true)
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{
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Console.WriteLine("Could not read keys. Please make sure the file exists and try again.");
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return false;
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}
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try
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{
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// Open the read and write on the same file for inplace processing
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using var input = File.Open(filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
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using var output = File.Open(filename, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
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// Deserialize the cart information
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var cart = N3DSDeserializer.DeserializeStream(input);
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if (cart?.Header == null || cart?.CardInfoHeader?.InitialData?.BackupHeader == null)
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{
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Console.WriteLine("Error: Not a 3DS cart image!");
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return false;
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}
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// Encrypt all 8 NCCH partitions
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EncryptAllPartitions(cart, force, input, output);
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return true;
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}
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catch
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{
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Console.WriteLine($"An error has occurred. {filename} may be corrupted if it was partially processed.");
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Console.WriteLine("Please check that the file was a valid 3DS or New 3DS cart image and try again.");
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return false;
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}
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}
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/// <inheritdoc/>
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public bool DecryptFile(string filename, bool force)
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{
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// Ensure the constants are all set
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if (_decryptArgs.IsReady != true)
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{
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Console.WriteLine("Could not read keys. Please make sure the file exists and try again.");
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return false;
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}
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try
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{
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// Open the read and write on the same file for inplace processing
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using var input = File.Open(filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
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using var output = File.Open(filename, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
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// Deserialize the cart information
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var cart = N3DSDeserializer.DeserializeStream(input);
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if (cart?.Header == null || cart?.CardInfoHeader?.InitialData?.BackupHeader == null)
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{
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Console.WriteLine("Error: Not a 3DS cart image!");
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return false;
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}
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// Decrypt all 8 NCCH partitions
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DecryptAllPartitions(cart, force, input, output);
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return true;
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}
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catch
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{
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Console.WriteLine($"An error has occurred. {filename} may be corrupted if it was partially processed.");
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Console.WriteLine("Please check that the file was a valid 3DS or New 3DS cart image and try again.");
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return false;
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}
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}
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#region Decrypt
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/// <summary>
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/// Decrypt all partitions in the partition table of an NCSD header
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/// </summary>
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="force">Indicates if the operation should be forced</param>
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/// <param name="input">Stream representing the input</param>
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/// <param name="output">Stream representing the output</param>
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private void DecryptAllPartitions(Cart cart, bool force, Stream input, Stream output)
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{
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// Check the partitions table
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if (cart.Header?.PartitionsTable == null || cart.Partitions == null)
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{
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Console.WriteLine("Invalid partitions table!");
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return;
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}
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// Iterate over all 8 NCCH partitions
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for (int p = 0; p < 8; p++)
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{
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// Check the partition exists
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if (cart.Partitions[p] == null)
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{
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Console.WriteLine($"Partition {p} Not found... Skipping...");
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continue;
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}
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// Decrypt the partition, if possible
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if (ShouldDecryptPartition(cart, p, force))
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DecryptPartition(cart, p, input, output);
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}
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}
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/// <summary>
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/// Determine if the current partition should be decrypted
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/// </summary>s
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private static bool ShouldDecryptPartition(Cart cart, int index, bool force)
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{
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// If we're forcing the operation, tell the user
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if (force)
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{
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Console.WriteLine($"Partition {index} is not verified due to force flag being set.");
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return true;
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}
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// If we're not forcing the operation, check if the 'NoCrypto' bit is set
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else if (cart.Partitions![index]!.Flags!.PossblyDecrypted())
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{
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Console.WriteLine($"Partition {index}: Already Decrypted?...");
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return false;
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}
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// By default, it passes
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return true;
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}
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/// <summary>
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/// Decrypt a single partition
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/// </summary>
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="index">Index of the partition</param>
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/// <param name="input">Stream representing the input</param>
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/// <param name="output">Stream representing the output</param>
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private void DecryptPartition(Cart cart, int index, Stream input, Stream output)
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{
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// Determine the keys needed for this partition
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SetDecryptionKeys(cart, index);
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// Decrypt the parts of the partition
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DecryptExtendedHeader(cart, index, input, output);
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DecryptExeFS(cart, index, input, output);
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DecryptRomFS(cart, index, input, output);
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// Update the flags
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UpdateDecryptCryptoAndMasks(cart, index, output);
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}
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/// <summary>
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/// Determine the set of keys to be used for decryption
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/// </summary>
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="index">Index of the partition</param>
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private void SetDecryptionKeys(Cart cart, int index)
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{
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// Get the partition
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var partition = cart.Partitions?[index];
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if (partition == null)
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return;
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// Get partition-specific values
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byte[]? rsaSignature = partition.RSA2048Signature;
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// Set the header to use based on mode
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BitMasks masks = partition.Flags!.BitMasks;
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CryptoMethod method = partition.Flags!.CryptoMethod;
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// Get the partition keys
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KeysMap[index] = new PartitionKeys(_decryptArgs, rsaSignature, masks, method, _development);
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}
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/// <summary>
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/// Decrypt the extended header, if it exists
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/// </summary>
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="index">Index of the partition</param>
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/// <param name="input">Stream representing the input</param>
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/// <param name="output">Stream representing the output</param>
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private bool DecryptExtendedHeader(Cart cart, int index, Stream input, Stream output)
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{
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// Get required offsets
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uint partitionOffset = GetPartitionOffset(cart, index);
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if (partitionOffset == 0)
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{
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Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
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return false;
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}
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uint extHeaderSize = GetExtendedHeaderSize(cart, index);
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if (extHeaderSize == 0)
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{
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Console.WriteLine($"Partition {index} RomFS: No Extended Header... Skipping...");
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return false;
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}
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// Seek to the extended header
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input.Seek(partitionOffset + 0x200, SeekOrigin.Begin);
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output.Seek(partitionOffset + 0x200, SeekOrigin.Begin);
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Console.WriteLine($"Partition {index} ExeFS: Decrypting: ExHeader");
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// Create the Plain AES cipher for this partition
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var cipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey2C, cart.PlainIV(index));
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// Process the extended header
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PerformAESOperation(Constants.CXTExtendedDataHeaderLength, cipher, input, output, null);
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#if NET6_0_OR_GREATER
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// In .NET 6.0, this operation is not picked up by the reader, so we have to force it to reload its buffer
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input.Seek(0, SeekOrigin.Begin);
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#endif
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output.Flush();
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return true;
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}
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/// <summary>
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/// Decrypt the ExeFS, if it exists
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/// </summary>
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="index">Index of the partition</param>
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/// <param name="input">Stream representing the input</param>
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/// <param name="output">Stream representing the output</param>
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private bool DecryptExeFS(Cart cart, int index, Stream input, Stream output)
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{
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// Validate the ExeFS
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uint exeFsOffset = GetExeFSOffset(cart, index);
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if (exeFsOffset == 0)
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{
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Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
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return false;
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}
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uint exeFsSize = GetExeFSSize(cart, index);
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if (exeFsSize == 0)
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{
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Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
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return false;
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}
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// Decrypt the filename table
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DecryptExeFSFilenameTable(cart, index, input, output);
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// For all but the original crypto method, process each of the files in the table
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if (cart.Partitions![index]!.Flags!.CryptoMethod != CryptoMethod.Original)
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DecryptExeFSFileEntries(cart, index, input, output);
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// Seek to the ExeFS
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input.Seek(exeFsOffset, SeekOrigin.Begin);
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output.Seek(exeFsOffset, SeekOrigin.Begin);
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// Create the ExeFS AES cipher for this partition
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int ctroffsetE = (int)(cart.MediaUnitSize() / 0x10);
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byte[] exefsIVWithOffset = AddToByteArray(cart.ExeFSIV(index), ctroffsetE);
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var cipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey2C, exefsIVWithOffset);
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// Setup and perform the decryption
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PerformAESOperation(exeFsSize,
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cipher,
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input,
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output,
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(string s) => Console.WriteLine($"\rPartition {index} ExeFS: Decrypting: {s}"));
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return true;
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}
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/// <summary>
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/// Decrypt the ExeFS Filename Table
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/// </summary>
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="index">Index of the partition</param>
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/// <param name="input">Stream representing the input</param>
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/// <param name="output">Stream representing the output</param>
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private void DecryptExeFSFilenameTable(Cart cart, int index, Stream input, Stream output)
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{
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// Get ExeFS offset
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uint exeFsOffset = GetExeFSOffset(cart, index);
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if (exeFsOffset == 0)
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{
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Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
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return;
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}
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// Seek to the ExeFS header
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input.Seek(exeFsOffset, SeekOrigin.Begin);
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output.Seek(exeFsOffset, SeekOrigin.Begin);
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Console.WriteLine($"Partition {index} ExeFS: Decrypting: ExeFS Filename Table");
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// Create the ExeFS AES cipher for this partition
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var cipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey2C, cart.ExeFSIV(index));
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// Process the filename table
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PerformAESOperation(cart.MediaUnitSize(), cipher, input, output, null);
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#if NET6_0_OR_GREATER
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// In .NET 6.0, this operation is not picked up by the reader, so we have to force it to reload its buffer
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input.Seek(0, SeekOrigin.Begin);
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#endif
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output.Flush();
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}
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/// <summary>
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/// Decrypt the ExeFS file entries
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/// </summary>
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="index">Index of the partition</param>
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/// <param name="input">Stream representing the input</param>
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/// <param name="output">Stream representing the output</param>
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private void DecryptExeFSFileEntries(Cart cart, int index, Stream input, Stream output)
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{
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// Get ExeFS offset
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uint exeFsHeaderOffset = GetExeFSOffset(cart, index);
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if (exeFsHeaderOffset == 0)
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{
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Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
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return;
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}
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// Get to the start of the files
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uint exeFsFilesOffset = exeFsHeaderOffset + cart.MediaUnitSize();
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input.Seek(exeFsHeaderOffset, SeekOrigin.Begin);
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var exefsHeader = N3DSDeserializer.ParseExeFSHeader(input);
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// If the header failed to read, log and return
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if (exefsHeader == null)
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{
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Console.WriteLine($"Partition {index} ExeFS header could not be read. Skipping...");
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return;
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}
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foreach (var fileHeader in exefsHeader.FileHeaders!)
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{
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// Only decrypt a file if it's a code binary
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if (fileHeader == null || !fileHeader.IsCodeBinary())
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continue;
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// Create the ExeFS AES ciphers for this partition
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uint ctroffset = (fileHeader.FileOffset + cart.MediaUnitSize()) / 0x10;
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byte[] exefsIVWithOffsetForHeader = AddToByteArray(cart.ExeFSIV(index), (int)ctroffset);
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var firstCipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey, exefsIVWithOffsetForHeader);
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var secondCipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey2C, exefsIVWithOffsetForHeader);
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// Seek to the file entry
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input.Seek(exeFsFilesOffset + fileHeader.FileOffset, SeekOrigin.Begin);
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output.Seek(exeFsFilesOffset + fileHeader.FileOffset, SeekOrigin.Begin);
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// Setup and perform the encryption
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uint exeFsSize = GetExeFSSize(cart, index);
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PerformAESOperation(exeFsSize,
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firstCipher,
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secondCipher,
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input,
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output,
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(string s) => Console.WriteLine($"\rPartition {index} ExeFS: Decrypting: {fileHeader.FileName}...{s}"));
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}
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}
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/// <summary>
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/// Decrypt the RomFS, if it exists
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/// </summary>
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="index">Index of the partition</param>
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/// <param name="input">Stream representing the input</param>
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/// <param name="output">Stream representing the output</param>
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private bool DecryptRomFS(Cart cart, int index, Stream input, Stream output)
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{
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// Validate the RomFS
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uint romFsOffset = GetRomFSOffset(cart, index);
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if (romFsOffset == 0)
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{
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Console.WriteLine($"Partition {index} RomFS: No Data... Skipping...");
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return false;
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}
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uint romFsSize = GetRomFSSize(cart, index);
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if (romFsSize == 0)
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{
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Console.WriteLine($"Partition {index} RomFS: No Data... Skipping...");
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return false;
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}
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// Seek to the RomFS
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input.Seek(romFsOffset, SeekOrigin.Begin);
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output.Seek(romFsOffset, SeekOrigin.Begin);
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// Create the RomFS AES cipher for this partition
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var cipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey, cart.RomFSIV(index));
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// Setup and perform the decryption
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PerformAESOperation(romFsSize,
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cipher,
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input,
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output,
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(string s) => Console.WriteLine($"\rPartition {index} RomFS: Decrypting: {s}"));
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return true;
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}
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/// <summary>
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/// Update the CryptoMethod and BitMasks for the decrypted partition
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/// </summary>
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="index">Index of the partition</param>
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/// <param name="output">Stream representing the output</param>
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private static void UpdateDecryptCryptoAndMasks(Cart cart, int index, Stream output)
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{
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// Get required offsets
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uint partitionOffset = GetPartitionOffset(cart, index);
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// Seek to the CryptoMethod location
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output.Seek(partitionOffset + 0x18B, SeekOrigin.Begin);
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// Write the new CryptoMethod
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output.Write((byte)CryptoMethod.Original);
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output.Flush();
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// Seek to the BitMasks location
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output.Seek(partitionOffset + 0x18F, SeekOrigin.Begin);
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// Write the new BitMasks flag
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BitMasks flag = cart.Partitions![index]!.Flags!.BitMasks;
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flag &= (BitMasks)((byte)(BitMasks.FixedCryptoKey | BitMasks.NewKeyYGenerator) ^ 0xFF);
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flag |= BitMasks.NoCrypto;
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output.Write((byte)flag);
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output.Flush();
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}
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#endregion
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#region Encrypt
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|
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/// <summary>
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/// Encrypt all partitions in the partition table of an NCSD header
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/// </summary>
|
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/// <param name="cart">Cart representing the 3DS file</param>
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/// <param name="force">Indicates if the operation should be forced</param>
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/// <param name="input">Stream representing the input</param>
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/// <param name="output">Stream representing the output</param>
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private void EncryptAllPartitions(Cart cart, bool force, Stream input, Stream output)
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{
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// Check the partitions table
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if (cart.Header?.PartitionsTable == null || cart.Partitions == null)
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{
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Console.WriteLine("Invalid partitions table!");
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return;
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}
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|
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// Iterate over all 8 NCCH partitions
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for (int p = 0; p < 8; p++)
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{
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// Check the partition exists
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if (cart.Partitions[p] == null)
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{
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Console.WriteLine($"Partition {p} Not found... Skipping...");
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continue;
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}
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// Encrypt the partition, if possible
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if (ShouldEncryptPartition(cart, p, force))
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EncryptPartition(cart, p, input, output);
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}
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}
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|
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/// <summary>
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/// Determine if the current partition should be encrypted
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/// </summary>
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private static bool ShouldEncryptPartition(Cart cart, int index, bool force)
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{
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// If we're forcing the operation, tell the user
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if (force)
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{
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Console.WriteLine($"Partition {index} is not verified due to force flag being set.");
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return true;
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}
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// If we're not forcing the operation, check if the 'NoCrypto' bit is set
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else if (!cart.Partitions![index]!.Flags!.PossblyDecrypted())
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{
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|
Console.WriteLine($"Partition {index}: Already Encrypted?...");
|
|
return false;
|
|
}
|
|
|
|
// By default, it passes
|
|
return true;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Encrypt a single partition
|
|
/// </summary>
|
|
/// <param name="cart">Cart representing the 3DS file</param>
|
|
/// <param name="index">Index of the partition</param>
|
|
/// <param name="input">Stream representing the input</param>
|
|
/// <param name="output">Stream representing the output</param>
|
|
private void EncryptPartition(Cart cart, int index, Stream input, Stream output)
|
|
{
|
|
// Determine the keys needed for this partition
|
|
SetEncryptionKeys(cart, index);
|
|
|
|
// Encrypt the parts of the partition
|
|
EncryptExtendedHeader(cart, index, input, output);
|
|
EncryptExeFS(cart, index, input, output);
|
|
EncryptRomFS(cart, index, input, output);
|
|
|
|
// Update the flags
|
|
UpdateEncryptCryptoAndMasks(cart, index, output);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Determine the set of keys to be used for encryption
|
|
/// </summary>
|
|
/// <param name="cart">Cart representing the 3DS file</param>
|
|
/// <param name="index">Index of the partition</param>
|
|
private void SetEncryptionKeys(Cart cart, int index)
|
|
{
|
|
// Get the partition
|
|
var partition = cart.Partitions?[index];
|
|
if (partition == null)
|
|
return;
|
|
|
|
// Get partition-specific values
|
|
byte[]? rsaSignature = partition.RSA2048Signature;
|
|
|
|
// Set the header to use based on mode
|
|
var backupHeader = cart.CardInfoHeader!.InitialData!.BackupHeader;
|
|
BitMasks masks = backupHeader!.Flags!.BitMasks;
|
|
CryptoMethod method = backupHeader.Flags.CryptoMethod;
|
|
|
|
// Get the partition keys
|
|
KeysMap[index] = new PartitionKeys(_decryptArgs, rsaSignature, masks, method, _development);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Encrypt the extended header, if it exists
|
|
/// </summary>
|
|
/// <param name="cart">Cart representing the 3DS file</param>
|
|
/// <param name="index">Index of the partition</param>
|
|
/// <param name="input">Stream representing the input</param>
|
|
/// <param name="output">Stream representing the output</param>
|
|
private bool EncryptExtendedHeader(Cart cart, int index, Stream input, Stream output)
|
|
{
|
|
// Get required offsets
|
|
uint partitionOffset = GetPartitionOffset(cart, index);
|
|
if (partitionOffset == 0)
|
|
{
|
|
Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
|
|
return false;
|
|
}
|
|
|
|
uint extHeaderSize = GetExtendedHeaderSize(cart, index);
|
|
if (extHeaderSize == 0)
|
|
{
|
|
Console.WriteLine($"Partition {index} RomFS: No Extended Header... Skipping...");
|
|
return false;
|
|
}
|
|
|
|
// Seek to the extended header
|
|
input.Seek(partitionOffset + 0x200, SeekOrigin.Begin);
|
|
output.Seek(partitionOffset + 0x200, SeekOrigin.Begin);
|
|
|
|
Console.WriteLine($"Partition {index} ExeFS: Encrypting: ExHeader");
|
|
|
|
// Create the Plain AES cipher for this partition
|
|
var cipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey2C, cart.PlainIV(index));
|
|
|
|
// Process the extended header
|
|
PerformAESOperation(Constants.CXTExtendedDataHeaderLength, cipher, input, output, null);
|
|
|
|
#if NET6_0_OR_GREATER
|
|
// In .NET 6.0, this operation is not picked up by the reader, so we have to force it to reload its buffer
|
|
input.Seek(0, SeekOrigin.Begin);
|
|
#endif
|
|
output.Flush();
|
|
return true;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Encrypt the ExeFS, if it exists
|
|
/// </summary>
|
|
/// <param name="cart">Cart representing the 3DS file</param>
|
|
/// <param name="index">Index of the partition</param>
|
|
/// <param name="input">Stream representing the input</param>
|
|
/// <param name="output">Stream representing the output</param>
|
|
private bool EncryptExeFS(Cart cart, int index, Stream input, Stream output)
|
|
{
|
|
// Validate the ExeFS
|
|
uint exeFsOffset = GetExeFSOffset(cart, index);
|
|
if (exeFsOffset == 0)
|
|
{
|
|
Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
|
|
return false;
|
|
}
|
|
|
|
uint exeFsSize = GetExeFSSize(cart, index);
|
|
if (exeFsSize == 0)
|
|
{
|
|
Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
|
|
return false;
|
|
}
|
|
|
|
// For all but the original crypto method, process each of the files in the table
|
|
var backupHeader = cart.CardInfoHeader!.InitialData!.BackupHeader;
|
|
if (backupHeader!.Flags!.CryptoMethod != CryptoMethod.Original)
|
|
EncryptExeFSFileEntries(cart, index, input, output);
|
|
|
|
// Encrypt the filename table
|
|
EncryptExeFSFilenameTable(cart, index, input, output);
|
|
|
|
// Seek to the ExeFS
|
|
input.Seek(exeFsOffset, SeekOrigin.Begin);
|
|
output.Seek(exeFsOffset, SeekOrigin.Begin);
|
|
|
|
// Create the ExeFS AES cipher for this partition
|
|
int ctroffsetE = (int)(cart.MediaUnitSize() / 0x10);
|
|
byte[] exefsIVWithOffset = AddToByteArray(cart.ExeFSIV(index), ctroffsetE);
|
|
var cipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey2C, exefsIVWithOffset);
|
|
|
|
// Setup and perform the encryption
|
|
PerformAESOperation(exeFsSize,
|
|
cipher,
|
|
input,
|
|
output,
|
|
(string s) => Console.WriteLine($"\rPartition {index} ExeFS: Encrypting: {s}"));
|
|
|
|
return true;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Encrypt the ExeFS Filename Table
|
|
/// </summary>
|
|
/// <param name="cart">Cart representing the 3DS file</param>
|
|
/// <param name="index">Index of the partition</param>
|
|
/// <param name="input">Stream representing the input</param>
|
|
/// <param name="output">Stream representing the output</param>
|
|
private void EncryptExeFSFilenameTable(Cart cart, int index, Stream input, Stream output)
|
|
{
|
|
// Get ExeFS offset
|
|
uint exeFsOffset = GetExeFSOffset(cart, index);
|
|
if (exeFsOffset == 0)
|
|
{
|
|
Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
|
|
return;
|
|
}
|
|
|
|
// Seek to the ExeFS header
|
|
input.Seek(exeFsOffset, SeekOrigin.Begin);
|
|
output.Seek(exeFsOffset, SeekOrigin.Begin);
|
|
|
|
Console.WriteLine($"Partition {index} ExeFS: Encrypting: ExeFS Filename Table");
|
|
|
|
// Create the ExeFS AES cipher for this partition
|
|
var cipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey2C, cart.ExeFSIV(index));
|
|
|
|
// Process the filename table
|
|
PerformAESOperation(cart.MediaUnitSize(), cipher, input, output, null);
|
|
|
|
#if NET6_0_OR_GREATER
|
|
// In .NET 6.0, this operation is not picked up by the reader, so we have to force it to reload its buffer
|
|
input.Seek(0, SeekOrigin.Begin);
|
|
#endif
|
|
output.Flush();
|
|
}
|
|
|
|
/// <summary>
|
|
/// Encrypt the ExeFS file entries
|
|
/// </summary>
|
|
/// <param name="cart">Cart representing the 3DS file</param>
|
|
/// <param name="index">Index of the partition</param>
|
|
/// <param name="input">Stream representing the input</param>
|
|
/// <param name="output">Stream representing the output</param>
|
|
private void EncryptExeFSFileEntries(Cart cart, int index, Stream input, Stream output)
|
|
{
|
|
// Get ExeFS offset
|
|
uint exeFsHeaderOffset = GetExeFSOffset(cart, index);
|
|
if (exeFsHeaderOffset == 0)
|
|
{
|
|
Console.WriteLine($"Partition {index} ExeFS: No Data... Skipping...");
|
|
return;
|
|
}
|
|
|
|
// Get to the start of the files
|
|
uint exeFsFilesOffset = exeFsHeaderOffset + cart.MediaUnitSize();
|
|
input.Seek(exeFsHeaderOffset, SeekOrigin.Begin);
|
|
var exefsHeader = N3DSDeserializer.ParseExeFSHeader(input);
|
|
|
|
// If the header failed to read, log and return
|
|
if (exefsHeader == null)
|
|
{
|
|
Console.WriteLine($"Partition {index} ExeFS header could not be read. Skipping...");
|
|
return;
|
|
}
|
|
|
|
foreach (var fileHeader in exefsHeader.FileHeaders!)
|
|
{
|
|
// Only decrypt a file if it's a code binary
|
|
if (fileHeader == null || !fileHeader.IsCodeBinary())
|
|
continue;
|
|
|
|
// Create the ExeFS AES ciphers for this partition
|
|
uint ctroffset = (fileHeader.FileOffset + cart.MediaUnitSize()) / 0x10;
|
|
byte[] exefsIVWithOffsetForHeader = AddToByteArray(cart.ExeFSIV(index), (int)ctroffset);
|
|
var firstCipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey, exefsIVWithOffsetForHeader);
|
|
var secondCipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey2C, exefsIVWithOffsetForHeader);
|
|
|
|
// Seek to the file entry
|
|
input.Seek(exeFsFilesOffset + fileHeader.FileOffset, SeekOrigin.Begin);
|
|
output.Seek(exeFsFilesOffset + fileHeader.FileOffset, SeekOrigin.Begin);
|
|
|
|
// Setup and perform the encryption
|
|
uint exeFsSize = GetExeFSSize(cart, index);
|
|
PerformAESOperation(exeFsSize,
|
|
firstCipher,
|
|
secondCipher,
|
|
input,
|
|
output,
|
|
(string s) => Console.WriteLine($"\rPartition {index} ExeFS: Encrypting: {fileHeader.FileName}...{s}"));
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Encrypt the RomFS, if it exists
|
|
/// </summary>
|
|
/// <param name="cart">Cart representing the 3DS file</param>
|
|
/// <param name="index">Index of the partition</param>
|
|
/// <param name="input">Stream representing the input</param>
|
|
/// <param name="output">Stream representing the output</param>
|
|
private bool EncryptRomFS(Cart cart, int index, Stream input, Stream output)
|
|
{
|
|
// Validate the RomFS
|
|
uint romFsOffset = GetRomFSOffset(cart, index);
|
|
if (romFsOffset == 0)
|
|
{
|
|
Console.WriteLine($"Partition {index} RomFS: No Data... Skipping...");
|
|
return false;
|
|
}
|
|
|
|
uint romFsSize = GetRomFSSize(cart, index);
|
|
if (romFsSize == 0)
|
|
{
|
|
Console.WriteLine($"Partition {index} RomFS: No Data... Skipping...");
|
|
return false;
|
|
}
|
|
|
|
// Seek to the RomFS
|
|
input.Seek(romFsOffset, SeekOrigin.Begin);
|
|
output.Seek(romFsOffset, SeekOrigin.Begin);
|
|
|
|
// Force setting encryption keys for partitions 1 and above
|
|
if (index > 0)
|
|
{
|
|
var backupHeader = cart.CardInfoHeader!.InitialData!.BackupHeader;
|
|
KeysMap[index].SetRomFSValues(backupHeader!.Flags!.BitMasks);
|
|
}
|
|
|
|
// Create the RomFS AES cipher for this partition
|
|
var cipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey, cart.RomFSIV(index));
|
|
|
|
// Setup and perform the decryption
|
|
PerformAESOperation(romFsSize,
|
|
cipher,
|
|
input,
|
|
output,
|
|
(string s) => Console.WriteLine($"\rPartition {index} RomFS: Encrypting: {s}"));
|
|
|
|
return true;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Update the CryptoMethod and BitMasks for the encrypted partition
|
|
/// </summary>
|
|
/// <param name="cart">Cart representing the 3DS file</param>
|
|
/// <param name="index">Index of the partition</param>
|
|
/// <param name="output">Stream representing the output</param>
|
|
private static void UpdateEncryptCryptoAndMasks(Cart cart, int index, Stream output)
|
|
{
|
|
// Get required offsets
|
|
uint partitionOffset = GetPartitionOffset(cart, index);
|
|
|
|
// Get the backup header
|
|
var backupHeader = cart.CardInfoHeader!.InitialData!.BackupHeader;
|
|
|
|
// Seek to the CryptoMethod location
|
|
output.Seek(partitionOffset + 0x18B, SeekOrigin.Begin);
|
|
|
|
// Write the new CryptoMethod
|
|
// - For partitions 1 and up, set crypto-method to 0x00
|
|
// - If partition 0, restore crypto-method from backup flags
|
|
byte cryptoMethod = index > 0 ? (byte)CryptoMethod.Original : (byte)backupHeader!.Flags!.CryptoMethod;
|
|
output.Write(cryptoMethod);
|
|
output.Flush();
|
|
|
|
// Seek to the BitMasks location
|
|
output.Seek(partitionOffset + 0x18F, SeekOrigin.Begin);
|
|
|
|
// Write the new BitMasks flag
|
|
BitMasks flag = cart.Partitions![index]!.Flags!.BitMasks;
|
|
flag &= (BitMasks.FixedCryptoKey | BitMasks.NewKeyYGenerator | BitMasks.NoCrypto) ^ (BitMasks)0xFF;
|
|
flag |= (BitMasks.FixedCryptoKey | BitMasks.NewKeyYGenerator) & backupHeader!.Flags!.BitMasks;
|
|
output.Write((byte)flag);
|
|
output.Flush();
|
|
}
|
|
|
|
#endregion
|
|
}
|
|
}
|