public override int Read(byte[] buf, int index, int count)
{
int total_read = 0;
bool refill_buffer = !(m_position >= m_current_block_position && m_position < m_current_block_position + m_current_block_length);
while (count > 0 && m_position < m_max_offset)
{
if (refill_buffer)
{
int block_num = (int)(m_position / BlockLength);
m_current_block_position = m_position & ~((long)BlockLength - 1);
m_current_block_length = m_view.Read(m_current_block_position, m_current_block, 0, (uint)BlockLength);
DecryptBlock(block_num);
}
int src_offset = (int)m_position & (BlockLength - 1);
int available = Math.Min(count, m_current_block_length - src_offset);
Buffer.BlockCopy(m_current_block, src_offset, buf, index, available);
m_position += available;
total_read += available;
index += available;
count -= available;
refill_buffer = true;
}
return(total_read);
}
private void FillBuffer()
{
m_current_block_length = m_view.Read(m_current_block_position, m_current_block, 0, (uint)BlockLength);
for (int offset = 0; offset < m_current_block_length; offset += 0x10)
{
m_enc.DecryptBlock(m_current_block_position + offset, m_current_block, offset);
}
}
static byte[] ReadBlock(ArcView.Frame view, INekoFormat enc, long offset, out int length)
{
uint hash = view.ReadUInt32(offset);
length = view.ReadInt32(offset + 4);
int aligned_size = (length + 7) & ~7;
byte[] buffer = new byte[aligned_size];
length = view.Read(offset + 8, buffer, 0, (uint)length);
if (0 != hash)
{
enc.Decrypt(hash, buffer, 0, aligned_size);
}
return(buffer);
}
bool ReadBlock()
{
if (m_position >= m_length)
{
return(false);
}
m_block_start = m_position & ~0xFFFL;
m_block_length = m_view.Read(m_block_start, m_block, 0, 0x1000);
if (m_block_length != 0x1000)
{
return(false);
}
using (var decryptor = m_encryption.CreateDecryptor((int)(m_block_start >> 12)))
using (var enc = new BinMemoryStream(m_block))
using (var dec = new InputCryptoStream(enc, decryptor))
dec.Read(m_block, 0, m_block_length);
return(true);
}
static byte[] ReadBlock(ArcView.Frame view, INekoEncryption enc, long offset, out int length)
{
uint hash = view.ReadUInt32(offset);
length = view.ReadInt32(offset + 4);
// parity check
// if (CalcParity (((NekoEncryption32bit)enc).Parity, (uint)length) != hash)
// throw new InvalidFormatException();
int aligned_size = (length + 7) & ~7;
byte[] buffer = new byte[aligned_size];
length = view.Read(offset + 8, buffer, 0, (uint)length);
if (0 != hash)
{
enc.Decrypt(hash, buffer, 0, aligned_size);
}
return(buffer);
}
private static int ReadEncrypted(ArcView.Frame view, IMalieDecryptor dec, long offset, byte[] buffer, int index, int length)
{
int offset_pad = (int)offset & 0xF;
int aligned_len = (offset_pad + length + 0xF) & ~0xF;
byte[] aligned_buf;
int block = 0;
if (aligned_len == length)
{
aligned_buf = buffer;
block = index;
}
else
{
aligned_buf = new byte[aligned_len];
}
int read = view.Read(offset - offset_pad, aligned_buf, block, (uint)aligned_len);
if (read < offset_pad)
{
return(0);
}
for (int block_count = aligned_len / 0x10; block_count > 0; --block_count)
{
dec.DecryptBlock(offset, aligned_buf, block);
block += 0x10;
offset += 0x10;
}
if (aligned_buf != buffer)
{
Buffer.BlockCopy(aligned_buf, offset_pad, buffer, index, length);
}
return(Math.Min(length, read - offset_pad));
}