public void DeriveSdCardKeys()
{
var sdKek = new byte[0x10];
GenerateKek(MasterKeys[0], SdCardKekSource, sdKek, AesKekGenerationSource, AesKeyGenerationSource);
for (int k = 0; k < SdCardKeyIdCount; k++)
{
for (int i = 0; i < 0x20; i++)
{
SdCardKeySourcesSpecific[k][i] = (byte)(SdCardKeySources[k][i] ^ SdSeed[i & 0xF]);
}
}
for (int k = 0; k < SdCardKeyIdCount; k++)
{
Aes.DecryptEcb128(SdCardKeySourcesSpecific[k], SdCardKeys[k], sdKek);
}
// Derive sd card save key
if (!SaveMacSdCardKekSource.IsEmpty() && !SaveMacSdCardKeySource.IsEmpty())
{
var keySource = new byte[0x10];
for (int i = 0; i < 0x10; i++)
{
keySource[i] = (byte)(SaveMacSdCardKeySource[i] ^ SdSeed[i]);
}
GenerateKek(MasterKeys[0], SaveMacSdCardKekSource, sdKek, AesKekGenerationSource, null);
Aes.DecryptEcb128(keySource, SaveMacSdCardKey, sdKek);
}
}
private void DecryptKeyblobs(IProgressReport logger = null)
{
var cmac = new byte[0x10];
var expectedCmac = new byte[0x10];
var counter = new byte[0x10];
for (int i = 0; i < UsedKeyblobCount; i++)
{
if (KeyblobKeys[i].IsEmpty() || KeyblobMacKeys[i].IsEmpty() || EncryptedKeyblobs[i].IsEmpty())
{
continue;
}
Array.Copy(EncryptedKeyblobs[i], expectedCmac, 0x10);
Aes.CalculateCmac(cmac, EncryptedKeyblobs[i].AsSpan(0x10, 0xA0), KeyblobMacKeys[i]);
if (!Utilities.ArraysEqual(cmac, expectedCmac))
{
logger?.LogMessage($"Warning: Keyblob MAC {i:x2} is invalid. Are SBK/TSEC key correct?");
}
Array.Copy(EncryptedKeyblobs[i], 0x10, counter, 0, 0x10);
Aes.DecryptCtr128(EncryptedKeyblobs[i].AsSpan(0x20), Keyblobs[i], KeyblobKeys[i], counter);
}
}
private void DeriveKeyblobKeys()
{
if (SecureBootKey.IsEmpty() || TsecKey.IsEmpty())
{
return;
}
bool haveKeyblobMacKeySource = !MasterKeySource.IsEmpty();
var temp = new byte[0x10];
for (int i = 0; i < UsedKeyblobCount; i++)
{
if (KeyblobKeySources[i].IsEmpty())
{
continue;
}
Aes.DecryptEcb128(KeyblobKeySources[i], temp, TsecKey);
Aes.DecryptEcb128(temp, KeyblobKeys[i], SecureBootKey);
if (!haveKeyblobMacKeySource)
{
continue;
}
Aes.DecryptEcb128(KeyblobMacKeySource, KeyblobMacKeys[i], KeyblobKeys[i]);
}
}
private void Derive620MasterKeks()
{
for (int i = UsedKeyblobCount; i < 0x20; i++)
{
if (TsecRootKeys[i - UsedKeyblobCount].IsEmpty() || MasterKekSources[i].IsEmpty())
{
continue;
}
Aes.DecryptEcb128(MasterKekSources[i], MasterKeks[i], TsecRootKeys[i - UsedKeyblobCount]);
}
}
private void DeriveNcaHeaderKey()
{
if (HeaderKekSource.IsEmpty() || HeaderKeySource.IsEmpty() || MasterKeys[0].IsEmpty())
{
return;
}
var headerKek = new byte[0x10];
GenerateKek(MasterKeys[0], HeaderKekSource, headerKek, AesKekGenerationSource,
AesKeyGenerationSource);
Aes.DecryptEcb128(HeaderKeySource, HeaderKey, headerKek);
}
private void DerivePerConsoleKeys()
{
var kek = new byte[0x10];
// Derive the device key
if (!PerConsoleKeySource.IsEmpty() && !KeyblobKeys[0].IsEmpty())
{
Aes.DecryptEcb128(PerConsoleKeySource, DeviceKey, KeyblobKeys[0]);
}
// Derive save key
if (!SaveMacKekSource.IsEmpty() && !SaveMacKeySource.IsEmpty() && !DeviceKey.IsEmpty())
{
GenerateKek(DeviceKey, SaveMacKekSource, kek, AesKekGenerationSource, null);
Aes.DecryptEcb128(SaveMacKeySource, SaveMacKey, kek);
}
// Derive BIS keys
if (DeviceKey.IsEmpty() ||
BisKekSource.IsEmpty() ||
AesKekGenerationSource.IsEmpty() ||
AesKeyGenerationSource.IsEmpty() ||
RetailSpecificAesKeySource.IsEmpty())
{
return;
}
// If the user doesn't provide bis_key_source_03 we can assume it's the same as bis_key_source_02
if (BisKeySource[3].IsEmpty() && !BisKeySource[2].IsEmpty())
{
Array.Copy(BisKeySource[2], BisKeySource[3], 0x20);
}
Aes.DecryptEcb128(RetailSpecificAesKeySource, kek, DeviceKey);
if (!BisKeySource[0].IsEmpty())
{
Aes.DecryptEcb128(BisKeySource[0], BisKeys[0], kek);
}
GenerateKek(DeviceKey, BisKekSource, kek, AesKekGenerationSource, AesKeyGenerationSource);
for (int i = 1; i < 4; i++)
{
if (!BisKeySource[i].IsEmpty())
{
Aes.DecryptEcb128(BisKeySource[i], BisKeys[i], kek);
}
}
}
public static void GenerateKek(byte[] key, byte[] src, byte[] dest, byte[] kekSeed, byte[] keySeed)
{
var kek = new byte[Aes.KeySize128];
var srcKek = new byte[Aes.KeySize128];
Aes.DecryptEcb128(kekSeed, kek, key);
Aes.DecryptEcb128(src, srcKek, kek);
if (keySeed != null)
{
Aes.DecryptEcb128(keySeed, dest, srcKek);
}
else
{
Array.Copy(srcKek, dest, Aes.KeySize128);
}
}
private static void GenerateKek(ReadOnlySpan <byte> key, ReadOnlySpan <byte> src, Span <byte> dest, ReadOnlySpan <byte> kekSeed, ReadOnlySpan <byte> keySeed)
{
Span <byte> kek = stackalloc byte[0x10];
Span <byte> srcKek = stackalloc byte[0x10];
Aes.DecryptEcb128(kekSeed, kek, key);
Aes.DecryptEcb128(src, srcKek, kek);
if (!keySeed.IsEmpty)
{
Aes.DecryptEcb128(keySeed, dest, srcKek);
}
else
{
srcKek.CopyTo(dest);
}
}
private void DeriveMasterKeys()
{
if (MasterKeySource.IsEmpty())
{
return;
}
for (int i = 0; i < 0x20; i++)
{
if (MasterKeks[i].IsEmpty())
{
continue;
}
Aes.DecryptEcb128(MasterKeySource, MasterKeys[i], MasterKeks[i]);
}
}
private void DerivePerFirmwareKeys()
{
bool haveKakSource0 = !KeyAreaKeyApplicationSource.IsEmpty();
bool haveKakSource1 = !KeyAreaKeyOceanSource.IsEmpty();
bool haveKakSource2 = !KeyAreaKeySystemSource.IsEmpty();
bool haveTitleKekSource = !TitleKekSource.IsEmpty();
bool havePackage2KeySource = !Package2KeySource.IsEmpty();
for (int i = 0; i < 0x20; i++)
{
if (MasterKeys[i].IsEmpty())
{
continue;
}
if (haveKakSource0)
{
GenerateKek(MasterKeys[i], KeyAreaKeyApplicationSource, KeyAreaKeys[i][0],
AesKekGenerationSource, AesKeyGenerationSource);
}
if (haveKakSource1)
{
GenerateKek(MasterKeys[i], KeyAreaKeyOceanSource, KeyAreaKeys[i][1],
AesKekGenerationSource, AesKeyGenerationSource);
}
if (haveKakSource2)
{
GenerateKek(MasterKeys[i], KeyAreaKeySystemSource, KeyAreaKeys[i][2],
AesKekGenerationSource, AesKeyGenerationSource);
}
if (haveTitleKekSource)
{
Aes.DecryptEcb128(TitleKekSource, TitleKeks[i], MasterKeys[i]);
}
if (havePackage2KeySource)
{
Aes.DecryptEcb128(Package2KeySource, Package2Keys[i], MasterKeys[i]);
}
}
}
