/*****************
* protected methods
*/
/*****************
* public methods
*/
//meant to avoid code repetition (is called from OTFontVal too)
public bool ValidateTable(OTTable table, Validator v, DirectoryEntry de, OTFontVal fontOwner)
{
String tname = GetTableManager().GetUnaliasedTableName(de.tag);
bool bRet = true;
// verify the checksum value from the directory entry matches the checksum for the table
if (!(tname == "DSIG" && IsCollection()))
{
uint calcChecksum = 0;
if (table != null)
{
calcChecksum = table.CalcChecksum();
}
if (de.checkSum != calcChecksum)
{
string s = "table '" + de.tag + "', calc: 0x" + calcChecksum.ToString("x8") + ", font: 0x" + de.checkSum.ToString("x8");
v.Error(T.T_NULL, E._DE_E_ChecksumError, de.tag, s);
bRet = false;
}
}
// verify that table has pad bytes set to zero
if (table != null)
{
uint nBytes = 0;
try {
nBytes = GetNumPadBytesAfterTable(table);
}
catch (Exception e)
{
v.ApplicationError(T.T_NULL, E._Table_E_Exception, de.tag, "GetNumPadBytesAfterTable: " + e.Message);
bRet = false;
}
bool bPadBytesZero = true;
if (nBytes != 0)
{
long PadFilePos = table.GetBuffer().GetFilePos() + table.GetBuffer().GetLength();
byte[] padbuf = ReadBytes(PadFilePos, nBytes);
for (int iByte = 0; iByte < padbuf.Length; iByte++)
{
if (padbuf[iByte] != 0)
{
bPadBytesZero = false;
break;
}
}
}
if (bPadBytesZero == false)
{
v.Warning(T.T_NULL, W._DE_W_PadBytesNotZero, de.tag, "after " + de.tag + " table");
}
}
// ask the table object to validate its data
if (!(tname == "DSIG" && IsCollection()))
{
v.OnTableValidationEvent(de, true);
}
if (table != null)
{
if (v.TestTable(de.tag)) // don't test deselected tables
{
try
{
ITableValidate valtable = (ITableValidate)table;
bRet &= valtable.Validate(v, fontOwner);
}
catch (InvalidCastException e)
{
v.ApplicationError(T.T_NULL, E._Table_E_Exception, table.m_tag, e.ToString());
bRet = false;
}
}
else
{
v.Info(I._Table_I_NotSelected, de.tag);
}
}
else
{
if (de.length == 0)
{
// check if it's a known OT table type since zero length private tables seem allowable
if (TableManager.IsKnownOTTableType(de.tag))
{
v.Error(T.T_NULL, E._Table_E_Invalid, de.tag, "The directory entry length is zero");
bRet = false;
}
}
else if (de.offset == 0)
{
v.Error(T.T_NULL, E._Table_E_Invalid, de.tag, "The directory entry offset is zero");
bRet = false;
}
else if (de.offset > GetFileLength())
{
v.Error(T.T_NULL, E._Table_E_Invalid, de.tag, "The table offset points past end of file");
bRet = false;
}
else if (de.offset + de.length > GetFileLength())
{
v.Error(T.T_NULL, E._Table_E_Invalid, de.tag, "The table extends past end of file");
bRet = false;
}
else
{
v.Error(E._Table_E_Invalid, de.tag);
bRet = false;
}
}
if (!(tname == "DSIG" && IsCollection()))
{
v.OnTableValidationEvent(de, false);
}
return(bRet);
}
static byte[] get_TTF_digest(OTFile f)
{
OTFont fn = f.GetFont(0);
Table_DSIG tDSIG = (Table_DSIG)fn.GetTable("DSIG");
DirectoryEntry deDSIG = null;
// sort table by offset
Dictionary <uint, int> offsetlookup = new Dictionary <uint, int>();
var list = new List <uint>();
for (ushort i = 0; i < fn.GetNumTables(); i++)
{
DirectoryEntry de = fn.GetDirectoryEntry(i);
offsetlookup.Add(de.offset, i);
list.Add(de.offset);
if ((string)de.tag == "DSIG")
{
deDSIG = de;
}
}
list.Sort();
// New offset table
var old_ot = fn.GetOffsetTable();
OffsetTable ot = new OffsetTable(old_ot.sfntVersion, (ushort)(old_ot.numTables - 1));
for (ushort i = 0; i < fn.GetNumTables(); i++)
{
DirectoryEntry oldde = fn.GetDirectoryEntry(i);
if ((string)oldde.tag != "DSIG")
{
DirectoryEntry de = new DirectoryEntry(oldde);
de.offset -= 16; // one less entry
if (de.offset > deDSIG.offset)
{
de.offset -= tDSIG.GetBuffer().GetPaddedLength();
}
ot.DirectoryEntries.Add(de);
}
}
hash.TransformBlock(ot.m_buf.GetBuffer(), 0, (int)ot.m_buf.GetLength(), ot.m_buf.GetBuffer(), 0);
for (int i = 0; i < ot.DirectoryEntries.Count; i++)
{
DirectoryEntry de = (DirectoryEntry)ot.DirectoryEntries[i];
hash.TransformBlock(de.m_buf.GetBuffer(), 0, (int)de.m_buf.GetLength(), de.m_buf.GetBuffer(), 0);
}
Table_head headTable = (Table_head)fn.GetTable("head");
// calculate the checksum
uint sum = 0;
sum += ot.CalcOffsetTableChecksum();
sum += ot.CalcDirectoryEntriesChecksum();
foreach (var key in list)
{
OTTable table = fn.GetTable((ushort)offsetlookup[key]);
if ((string)table.GetTag() != "DSIG")
{
sum += table.CalcChecksum();
}
}
Table_head.head_cache headCache = (Table_head.head_cache)headTable.GetCache();
// set the checkSumAdujustment field
headCache.checkSumAdjustment = 0xb1b0afba - sum;
Table_head newHead = (Table_head)headCache.GenerateTable();
foreach (var key in list)
{
OTTable table = fn.GetTable((ushort)offsetlookup[key]);
if ((string)table.GetTag() == "head")
{
table = newHead;
}
if ((string)table.GetTag() != "DSIG")
{
hash.TransformBlock(table.m_bufTable.GetBuffer(), 0, (int)table.GetBuffer().GetPaddedLength(),
table.m_bufTable.GetBuffer(), 0);
}
}
byte[] usFlag = { 0, 1 };
hash.TransformFinalBlock(usFlag, 0, 2);
return(hash.Hash);
}
