mirror of
https://github.com/kwsch/PKHeX
synced 2024-12-24 19:33:10 +00:00
fc754b346b
[Language Reference](https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/csharp-10.0/file-scoped-namespaces) Updates all the files, one less level of indentation. Some small changes were made to API surfaces, renaming `PKM pkm` -> `PKM pk`, and `LegalityAnalysis.pkm` -> `LegalityAnalysis.Entity`
74 lines
2.5 KiB
C#
74 lines
2.5 KiB
C#
using System;
|
|
using static System.Buffers.Binary.BinaryPrimitives;
|
|
|
|
namespace PKHeX.Core;
|
|
|
|
/// <summary>
|
|
/// Genius Sonority's logic for <see cref="GameVersion.XD"/> and <see cref="GameVersion.BATREV"/> encryption.
|
|
/// </summary>
|
|
public static class GeniusCrypto
|
|
{
|
|
public static void ReadKeys(ReadOnlySpan<byte> input, Span<ushort> keys)
|
|
{
|
|
for (int i = 0; i < keys.Length; i++)
|
|
keys[i] = ReadUInt16BigEndian(input[(i * 2)..]);
|
|
}
|
|
|
|
public static void Decrypt(ReadOnlySpan<byte> input, Span<byte> output, Span<ushort> keys)
|
|
{
|
|
if (keys.Length != 4)
|
|
throw new ArgumentOutOfRangeException(nameof(keys));
|
|
|
|
int i = 0;
|
|
do
|
|
{
|
|
foreach (var key in keys)
|
|
{
|
|
ushort value = ReadUInt16BigEndian(input[i..]);
|
|
value -= key;
|
|
WriteUInt16BigEndian(output[i..], value);
|
|
i += 2;
|
|
}
|
|
AdvanceKeys(keys);
|
|
} while (i != input.Length);
|
|
}
|
|
|
|
public static void Encrypt(ReadOnlySpan<byte> input, Span<byte> output, Span<ushort> keys)
|
|
{
|
|
if (keys.Length != 4)
|
|
throw new ArgumentOutOfRangeException(nameof(keys));
|
|
|
|
int i = 0;
|
|
do
|
|
{
|
|
foreach (var key in keys)
|
|
{
|
|
ushort value = ReadUInt16BigEndian(input[i..]);
|
|
value += key;
|
|
WriteUInt16BigEndian(output[i..], value);
|
|
i += 2;
|
|
}
|
|
AdvanceKeys(keys);
|
|
} while (i != input.Length);
|
|
}
|
|
|
|
private static void AdvanceKeys(Span<ushort> keys)
|
|
{
|
|
var k3 = keys[3] + 0x13;
|
|
var k2 = keys[2] + 0x17;
|
|
var k1 = keys[1] + 0x29;
|
|
var k0 = keys[0] + 0x43;
|
|
|
|
// Rotate 4bit groups across the diagonal [ / ] after biasing each u16 (no overflow):
|
|
// 0123 FB73
|
|
// 4567 EA62
|
|
// 89AB becomes D951
|
|
// CDEF C840
|
|
// We can leave our intermediary types as int as the bit-masks remove any overflow.
|
|
|
|
keys[3] = (ushort)(((k0 >> 12) & 0xf) | ((k1 >> 8) & 0xf0) | ((k2 >> 4) & 0xf00) | ( k3 & 0xf000));
|
|
keys[2] = (ushort)(((k0 >> 08) & 0xf) | ((k1 >> 4) & 0xf0) | ( k2 & 0xf00) | ((k3 << 04) & 0xf000));
|
|
keys[1] = (ushort)(((k0 >> 04) & 0xf) | ( k1 & 0xf0) | ((k2 << 4) & 0xf00) | ((k3 << 08) & 0xf000));
|
|
keys[0] = (ushort)(( k0 & 0xf) | ((k1 << 4) & 0xf0) | ((k2 << 8) & 0xf00) | ((k3 << 12) & 0xf000));
|
|
}
|
|
}
|