public static RSAParameters DecryptRsaKey(byte[] encryptedKey, byte[] kek) { var counter = new byte[0x10]; Array.Copy(encryptedKey, counter, 0x10); var body = new byte[0x230]; Array.Copy(encryptedKey, 0x10, body, 0, 0x230); var dec = new byte[0x230]; using (var streamDec = new RandomAccessSectorStream(new Aes128CtrStream(new MemoryStream(body), kek, counter))) { streamDec.Read(dec, 0, dec.Length); } var d = new byte[0x100]; var n = new byte[0x100]; var e = new byte[4]; Array.Copy(dec, 0, d, 0, 0x100); Array.Copy(dec, 0x100, n, 0, 0x100); Array.Copy(dec, 0x200, e, 0, 4); BigInteger dInt = GetBigInteger(d); BigInteger nInt = GetBigInteger(n); BigInteger eInt = GetBigInteger(e); RSAParameters rsaParams = RecoverRsaParameters(nInt, eInt, dInt); TestRsaKey(rsaParams); return(rsaParams); }
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 < 0x20; i++) { if (KeyblobKeys[i].IsEmpty() || KeyblobMacKeys[i].IsEmpty() || EncryptedKeyblobs[i].IsEmpty()) { continue; } Array.Copy(EncryptedKeyblobs[i], expectedCmac, 0x10); Crypto.CalculateAesCmac(KeyblobMacKeys[i], EncryptedKeyblobs[i], 0x10, cmac, 0, 0xa0); if (!Util.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); using (var keyblobDec = new RandomAccessSectorStream(new Aes128CtrStream( new MemoryStream(EncryptedKeyblobs[i], 0x20, Keyblobs[i].Length), KeyblobKeys[i], counter))) { keyblobDec.Read(Keyblobs[i], 0, Keyblobs[i].Length); } } }
public BktrCryptoStream(Stream baseStream, byte[] key, long offset, long length, long counterOffset, byte[] ctrHi, BktrSuperblock bktr) : base(baseStream, key, offset, length, counterOffset, ctrHi) { BktrHeader header = bktr.SubsectionHeader; byte[] subsectionBytes; using (var streamDec = new RandomAccessSectorStream(new Aes128CtrStream(baseStream, key, offset, length, counterOffset, ctrHi))) { streamDec.Position = header.Offset; subsectionBytes = new byte[header.Size]; streamDec.Read(subsectionBytes, 0, subsectionBytes.Length); } using (var reader = new BinaryReader(new MemoryStream(subsectionBytes))) { SubsectionBlock = new SubsectionBlock(reader); } foreach (SubsectionBucket bucket in SubsectionBlock.Buckets) { SubsectionEntries.AddRange(bucket.Entries); } // Add a subsection for the BKTR headers to make things easier var headerSubsection = new SubsectionEntry { Offset = bktr.RelocationHeader.Offset, Counter = (uint)(ctrHi[4] << 24 | ctrHi[5] << 16 | ctrHi[6] << 8 | ctrHi[7]), OffsetEnd = long.MaxValue }; SubsectionEntries.Add(headerSubsection); for (int i = 0; i < SubsectionEntries.Count - 1; i++) { SubsectionEntries[i].Next = SubsectionEntries[i + 1]; SubsectionEntries[i].OffsetEnd = SubsectionEntries[i + 1].Offset; } SubsectionOffsets = SubsectionEntries.Select(x => x.Offset).ToList(); CurrentEntry = GetSubsectionEntry(0); UpdateCounterSubsection(CurrentEntry.Counter); baseStream.Position = offset; }