public static unsafe void CalculateHMAC(int pg_offset, uint filesize, byte[] page_signatures, byte *result)
{
var b = CalculateHMAC(pg_offset, filesize, page_signatures);
var buf = new ByteBufferRef(new IntPtr(result), (int)SHA1Managed.SHA1HashSize);
buf.CopyFrom(0, b);
}
private void SerializeMetadata(ByteBufferRef buf, int cursor)
{
Deserializer.WriteULong(HeaderMagic, buf, cursor);
cursor += sizeof(ulong);
var hmac = CalculateHMAC(DataPageOffset, FileSize, Signatures);
buf.CopyFrom(cursor, hmac);
cursor += HMACSize;
Deserializer.WriteInt(DataPageOffset, buf, cursor);
cursor += sizeof(int);
Deserializer.WriteUInt(FileSize, buf, cursor);
cursor += sizeof(uint);
Deserializer.WriteInt(Signatures.Length, buf, cursor);
cursor += sizeof(int);
buf.CopyFrom(cursor, Signatures);
}
private static int ReadUserBuffer(Thread current, ByteBufferRef src, int buf_offset, CachePage page, int page_offset, int len)
{
var dst = new ByteBufferRef(page.Buffer.Location + page_offset, len);
dst.CopyFrom(buf_offset, src);
return(0);
}
private int PrepareBuffer(ByteBufferRef buf, CachePage[] sealed_page)
{
var cursor = 0;
// Metadata
for (var i = 0; i < DataPageOffset; ++i)
{
Deserializer.WriteInt(i, buf, cursor);
cursor += sizeof(int);
}
for (var i = 0; i < sealed_page.Length; ++i)
{
var pgoffset = sealed_page[i].Location;
Deserializer.WriteInt(pgoffset + DataPageOffset, buf, cursor);
cursor += sizeof(int);
if (pgoffset > MaximumPageOffset())
{
Arch.Console.WriteLine("SecureFSINode::FlushAndCloseAsync, file too big");
Utils.Panic();
return(-1);
}
}
var metadata_cursor = cursor;
cursor += DataPageOffset * Arch.ArchDefinition.PageSize;
// Copy data
var sha1 = new SHA1Managed();
for (var i = 0; i < sealed_page.Length; ++i)
{
var page = sealed_page[i];
buf.CopyFrom(cursor, page.Buffer);
sha1.Reset();
sha1.Input(page.Buffer);
var r = sha1.GetResult();
for (var j = 0; j < r.Length; ++j)
{
Signatures[page.Location * HMACSize + j] = r[j];
}
page.Dispose();
cursor += Arch.ArchDefinition.PageSize;
}
SerializeMetadata(buf, metadata_cursor);
return(0);
}