private bool ApplyPatch(FilePatch.Patch patch, Stream file)
{
// apply each patch
foreach (var address in patch.Addresses)
{
// find a matching data block
FilePatch.Data data = patch.Data.Find(
delegate(FilePatch.Data value)
{
if (address.Value.Equals(value.ID))
{
return(true);
}
return(false);
}
);
// error if a data block was not found
if (data == null)
{
ErrorMessages.Add(String.Format("A patch address references an invalid data id ({0}). Inform the developers of this", address.Value));
return(false);
}
// parse the address
uint pointer = 0;
if (!ParseHex(address.PTRString, out pointer))
{
ErrorMessages.Add(String.Format("Failed to parse an addresses pointer string ({0}). Inform the developers of this", address.Value));
return(false);
}
// write the data to the current address
if (!WriteData(pointer, data, file))
{
return(false);
}
}
return(true);
}
private bool WriteData(uint address, FilePatch.Data data, Stream output)
{
uint peaddress = 0;
if (!ParseHex(m_file_patch.PEAddressMaskString, out peaddress))
{
ErrorMessages.Add(String.Format("Failed to parse PE address mask string ({0}). Inform the developers of this.", data.ID));
return(false);
}
// calculate the byte address and move to it
long write_address = address - peaddress;
if (write_address >= output.Length)
{
ErrorMessages.Add(String.Format("Failed to write patch data ({0}) as the pointer is beyond the end of the file. Inform the developers of this.", data.ID));
return(false);
}
output.Seek(write_address, SeekOrigin.Begin);
int write_length = data.Length;
switch (data.Type)
{
case FilePatch.ValueType.String:
{
// default write length to te length of the string if zero
if (write_length == 0)
{
write_length = data.Value.Length;
}
if ((write_address + write_length) >= output.Length)
{
ErrorMessages.Add(String.Format("Failed to write patch data ({0}) as the data would write beyond the end of the file. Inform the developers of this.", data.ID));
return(false);
}
// write the strings bytes as ASCII
byte[] bytes = Encoding.ASCII.GetBytes(data.Value);
output.Write(bytes, 0, write_length);
// if necessary, write a null character to terminate the string
if (data.WriteNull)
{
output.WriteByte(0);
}
}
break;
case FilePatch.ValueType.UInteger32:
{
if ((write_address + 4) >= output.Length)
{
ErrorMessages.Add(String.Format("Failed to write patch data ({0}) as the data would write beyond the end of the file. Inform the developers of this.", data.ID));
return(false);
}
// try and parse the hex string
uint parsed_value;
if (!ParseHex(data.Value, out parsed_value))
{
ErrorMessages.Add(String.Format("Failed to parse a uint32 ({0}). Inform the developers of this.", data.ID));
return(false);
}
// swap the uint's endianness if required
if (data.SwapEndian)
{
uint endian_swapped = 0;
endian_swapped |= (uint)((parsed_value & 0xff000000) >> 24);
endian_swapped |= (uint)((parsed_value & 0x00ff0000) >> 8);
endian_swapped |= (uint)((parsed_value & 0x0000ff00) << 8);
endian_swapped |= (uint)((parsed_value & 0x000000ff) << 24);
parsed_value = endian_swapped;
}
// write the value to the stream
output.Write(BitConverter.GetBytes(parsed_value), 0, 4);
}
break;
case FilePatch.ValueType.UInteger16:
{
if ((write_address + 2) >= output.Length)
{
ErrorMessages.Add(String.Format("Failed to write patch data ({0}) as the data would write beyond the end of the file. Inform the developers of this.", data.ID));
return(false);
}
// try and parse the hex string
ushort parsed_value;
if (!ParseHex(data.Value, out parsed_value))
{
ErrorMessages.Add(String.Format("Failed to parse a uint16 ({0}). Inform the developers of this.", data.ID));
return(false);
}
// swap the uint's endianness if required
if (data.SwapEndian)
{
ushort endian_swapped = 0;
endian_swapped |= (ushort)((parsed_value & 0xff00) >> 8);
endian_swapped |= (ushort)((parsed_value & 0x00ff) << 8);
parsed_value = endian_swapped;
}
// write the value to the stream
output.Write(BitConverter.GetBytes(parsed_value), 0, 2);
}
break;
case FilePatch.ValueType.Byte:
{
if ((write_address + 1) >= output.Length)
{
ErrorMessages.Add(String.Format("Failed to write patch data ({0}) as the data would write beyond the end of the file. Inform the developers of this.", data.ID));
return(false);
}
// try and parse the hex string
byte parsed_value;
if (!ParseHex(data.Value, out parsed_value))
{
ErrorMessages.Add(String.Format("Failed to parse a byte ({0}). Inform the developers of this.", data.ID));
return(false);
}
// write the value to the stream
output.WriteByte(parsed_value);
}
break;
case FilePatch.ValueType.Bytes:
{
// check the strings length is a multiple of two
if (data.Value.Length % 2 != 0)
{
ErrorMessages.Add(String.Format("The length of a hex byte string ({0}) in the file patcher is odd. Inform the developers.", data.ID));
return(false);
}
// create the byte array
using (MemoryStream byte_stream = new MemoryStream())
{
// convert every two characters into a byte
for (int i = 0; i < data.Value.Length; i += 2)
{
byte parsed_byte = 0;
if (!ParseHex(data.Value.Substring(i, 2), out parsed_byte))
{
ErrorMessages.Add(String.Format("Failed to parse a byte array ({0}). Inform the developers of this.", data.ID));
return(false);
}
byte_stream.WriteByte(parsed_byte);
}
// default the write length to the array length if zero
if (write_length == 0)
{
write_length = (int)byte_stream.Length;
}
if ((write_address + write_length) >= output.Length)
{
ErrorMessages.Add(String.Format("Failed to write patch data ({0}) as the data would write beyond the end of the file. Inform the developers of this.", data.ID));
return(false);
}
// write the byte array to the stream
output.Write(byte_stream.GetBuffer(), 0, write_length);
}
}
break;
}
return(true);
}
