SabreTools/NDecrypt
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Code Issues 11 Packages Projects Releases 20 Wiki Activity

Fix IV and addition

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This commit is contained in:
Matt Nadareski
2024-11-14 00:26:58 -05:00
parent 3fbaedd7d5
commit 5aa50ee252
3 changed files with 28 additions and 14 deletions
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11
NDecrypt.Core/CommonOperations.cs
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@@ -134,9 +134,10 @@ namespace NDecrypt.Core
/// <param name="input">Byte array to add to</param>
/// <param name="add">Amount to add</param>
/// <returns>Byte array representing the new value</returns>
public static byte[] Add(byte[] input, int add)
public static byte[] Add(byte[] input, uint add)
{
byte[] addBytes = BitConverter.GetBytes(add);
Array.Reverse(addBytes);
byte[] paddedBytes = new byte[16];
Array.Copy(addBytes, 0, paddedBytes, 12, 4);
return Add(input, paddedBytes);
@@ -155,10 +156,10 @@ namespace NDecrypt.Core
byte[] output = new byte[outLength];
int carry = 0;
uint carry = 0;
for (int i = 0; i < addBytes; i++)
{
int addValue = left[i] + right[i] + carry;
uint addValue = (uint)(left[i] + right[i] + carry);
output[i] = (byte)addValue;
carry = addValue > byte.MaxValue ? byte.MaxValue - addValue : 0;
}
@@ -195,11 +196,11 @@ namespace NDecrypt.Core
// Shift by bits
while (r_bits-- > 0)
{
int carry = 0;
uint carry = 0;
for (int i = 0; i < val.Length; i++)
{
byte nextByte = (byte)((val[i] << 1) + carry);
carry = (val[i] << 1) > byte.MaxValue ? byte.MaxValue - (val[i] << 1) : 0;
carry = (uint)((val[i] << 1) > byte.MaxValue ? byte.MaxValue - (val[i] << 1) : 0);
val[i] = nextByte;
}

2
NDecrypt.Core/NDecrypt.Core.csproj
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@@ -47,7 +47,7 @@
<PackageReference Include="SabreTools.Hashing" Version="1.4.0" />
<PackageReference Include="SabreTools.IO" Version="1.5.0" />
<PackageReference Include="SabreTools.Models" Version="1.5.1" />
<PackageReference Include="SabreTools.Serialization" Version="1.7.1" />
<PackageReference Include="SabreTools.Serialization" Version="1.7.2" />
</ItemGroup>
</Project>

29
NDecrypt.Core/ThreeDSTool.cs
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@@ -282,8 +282,8 @@ namespace NDecrypt.Core
output.Seek(exeFsOffset, SeekOrigin.Begin);
// Create the ExeFS AES cipher for this partition
int ctroffsetE = (int)(cart.MediaUnitSize / 0x10);
byte[] exefsIVWithOffset = Add(cart.ExeFSIV(index), ctroffsetE);
uint ctroffsetE = cart.MediaUnitSize / 0x10;
byte[] exefsIVWithOffset = Add(FlipFirstHalf(cart.ExeFSIV(index)), ctroffsetE);
var cipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey2C!, exefsIVWithOffset);
// Setup and perform the decryption
@@ -373,7 +373,7 @@ namespace NDecrypt.Core
// Create the ExeFS AES ciphers for this partition
uint ctroffset = (fileHeader.FileOffset + cart.MediaUnitSize) / 0x10;
byte[] exefsIVWithOffsetForHeader = Add(cart.ExeFSIV(index), (int)ctroffset);
byte[] exefsIVWithOffsetForHeader = Add(FlipFirstHalf(cart.ExeFSIV(index)), ctroffset);
var firstCipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey!, exefsIVWithOffsetForHeader);
var secondCipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey2C!, exefsIVWithOffsetForHeader);
@@ -421,7 +421,7 @@ namespace NDecrypt.Core
output.Seek(romFsOffset, SeekOrigin.Begin);
// Create the RomFS AES cipher for this partition
var cipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey!, cart.RomFSIV(index));
var cipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey!, FlipFirstHalf(cart.RomFSIV(index)));
// Setup and perform the decryption
PerformAESOperation(romFsSize,
@@ -649,8 +649,8 @@ namespace NDecrypt.Core
output.Seek(exeFsHeaderOffset, SeekOrigin.Begin);
// Create the ExeFS AES cipher for this partition
int ctroffsetE = (int)(cart.MediaUnitSize / 0x10);
byte[] exefsIVWithOffset = Add(cart.ExeFSIV(index), ctroffsetE);
uint ctroffsetE = cart.MediaUnitSize / 0x10;
byte[] exefsIVWithOffset = Add(FlipFirstHalf(cart.ExeFSIV(index)), ctroffsetE);
var cipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey2C!, exefsIVWithOffset);
// Setup and perform the encryption
@@ -743,7 +743,7 @@ namespace NDecrypt.Core
// Create the ExeFS AES ciphers for this partition
uint ctroffset = (fileHeader.FileOffset + cart.MediaUnitSize) / 0x10;
byte[] exefsIVWithOffsetForHeader = Add(cart.ExeFSIV(index), (int)ctroffset);
byte[] exefsIVWithOffsetForHeader = Add(FlipFirstHalf(cart.ExeFSIV(index)), ctroffset);
var firstCipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey!, exefsIVWithOffsetForHeader);
var secondCipher = CreateAESDecryptionCipher(KeysMap[index].NormalKey2C!, exefsIVWithOffsetForHeader);
@@ -798,7 +798,7 @@ namespace NDecrypt.Core
}
// Create the RomFS AES cipher for this partition
var cipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey!, cart.RomFSIV(index));
var cipher = CreateAESEncryptionCipher(KeysMap[index].NormalKey!, FlipFirstHalf(cart.RomFSIV(index)));
// Setup and perform the decryption
PerformAESOperation(romFsSize,
@@ -846,5 +846,18 @@ namespace NDecrypt.Core
}
#endregion
// TODO: REMOVE WHEN SERIALIZATION FIXED
private static byte[] FlipFirstHalf(byte[] data)
{
byte[] toFlip = new byte[8];
Array.Copy(data, toFlip, 8);
Array.Reverse(toFlip);
byte[] output = new byte[16];
Array.Copy(toFlip, output, 8);
Array.Copy(data, 8, output, 8, 8);
return output;
}
}
}