private static string HashElf(ElfHeader elf, long basePosition, Stream input)
{
using (var sha1 = SHA1.Create())
{
foreach (var program in elf.ProgramHeaders)
{
var type = (uint)program.Type;
var flags = (uint)program.Flags;
sha1.TransformBlock(BitConverter.GetBytes(type.Swap()), 0, 4, null, 0);
sha1.TransformBlock(BitConverter.GetBytes(flags.Swap()), 0, 4, null, 0);
if (program.Type == Elf.ProgramType.Loadable && program.MemorySize > 0)
{
sha1.TransformBlock(BitConverter.GetBytes(program.VirtualAddress.Swap()), 0, 8, null, 0);
sha1.TransformBlock(BitConverter.GetBytes(program.MemorySize.Swap()), 0, 8, null, 0);
if (program.FileSize > 0)
{
if (basePosition + program.FileOffset + program.FileSize > input.Length)
{
return(null);
}
input.Position = basePosition + program.FileOffset;
var programBytes = input.ReadBytes((int)program.FileSize);
sha1.TransformBlock(programBytes, 0, programBytes.Length, null, 0);
}
}
}
sha1.TransformFinalBlock(new byte[0], 0, 0);
return(BitConverter.ToString(sha1.Hash).Replace("-", "").ToLowerInvariant());
}
}
private static int Run(string inputPath,
string patchPath,
string outputPath,
string verifyHash,
bool addCave,
long?desiredCaveAddress,
long?desiredCaveSize,
long?originalCodeSize)
{
using (var inputData = File.OpenRead(inputPath))
using (var patchData = File.OpenRead(patchPath))
{
var inputElf = ElfHeader.Read(inputData);
if (string.IsNullOrWhiteSpace(verifyHash) == false)
{
var inputHash = HashElf(inputElf, 0, inputData);
if (inputHash != verifyHash)
{
Console.WriteLine("Hash of input ELF does not match:");
Console.WriteLine(" desired: {0}", verifyHash);
Console.WriteLine(" actual: {0}", inputHash);
return(1);
}
}
int codeIndex = -1;
long newCodeSize = 0;
ulong caveVirtualAddress = 0;
long caveFileOffset = 0;
long caveFileSize = 0;
if (addCave == true)
{
codeIndex = Array.FindIndex(
inputElf.ProgramHeaders,
ph => ph.Type == Elf.ProgramType.Loadable &&
(ph.Flags & Elf.ProgramFlags.Executable) != 0);
if (codeIndex + 1 >= inputElf.ProgramHeaders.Length)
{
Console.WriteLine("No program following code program.");
return(2);
}
var codeHeader = inputElf.ProgramHeaders[codeIndex + 0];
var nextHeader = inputElf.ProgramHeaders[codeIndex + 1];
if ((ulong)codeHeader.FileSize != codeHeader.MemorySize)
{
Console.WriteLine("Code file size does not match memory size!");
return(3);
}
if (originalCodeSize.HasValue == true &&
originalCodeSize.Value != codeHeader.FileSize)
{
Console.WriteLine("Original code size does not match:");
Console.WriteLine(" desired: {0}", originalCodeSize.Value);
Console.WriteLine(" actual: {0}", codeHeader.FileSize);
return(4);
}
caveFileSize = nextHeader.FileOffset - (codeHeader.FileOffset + codeHeader.FileSize);
caveVirtualAddress = codeHeader.VirtualAddress + (ulong)codeHeader.FileSize;
caveFileOffset = codeHeader.FileOffset + codeHeader.FileSize;
if (desiredCaveAddress.HasValue == true &&
(ulong)desiredCaveAddress.Value != caveVirtualAddress)
{
Console.WriteLine("Desired cave virtual address does not match:");
Console.WriteLine(" desired: {0}", desiredCaveAddress.Value);
Console.WriteLine(" actual: {0}", caveVirtualAddress);
return(5);
}
if (desiredCaveSize.HasValue == true &&
desiredCaveSize.Value != caveFileSize)
{
Console.WriteLine("Desired cave size does not match:");
Console.WriteLine(" desired: {0}", desiredCaveSize.Value);
Console.WriteLine(" actual: {0}", caveFileSize);
return(6);
}
newCodeSize = nextHeader.FileOffset - codeHeader.FileOffset;
codeHeader.FileSize = newCodeSize;
codeHeader.MemorySize = (ulong)newCodeSize;
inputElf.ProgramHeaders[codeIndex] = codeHeader;
}
var patchElf = ElfHeader.Read(patchData);
var patchSectionIndex = Array.IndexOf(patchElf.SectionNames, ".patches");
if (patchSectionIndex < 0)
{
Console.WriteLine("No .patches section.");
return(7);
}
var patchSection = patchElf.SectionHeaders[patchSectionIndex];
var patchCount = patchSection.FileSize / 32;
var patchAddresses = new long[patchCount];
var patchSizes = new long[patchCount];
patchData.Position = patchSection.FileOffset;
for (int i = 0; i < patchSection.FileSize / 32; i++)
{
var patchAddressSource = patchData.ReadValueS64(Endian.Big);
var patchAddressStart = patchData.ReadValueS64(Endian.Big);
var patchAddressEnd = patchData.ReadValueS64(Endian.Big);
//var patchReserved = patchData.ReadValueS64(Endian.Big);
patchData.Position += 8;
if (patchAddressSource != patchAddressStart)
{
Console.WriteLine(
"Patch #{0} has mismatching source and start ({1:X} vs {2:X})",
i + 1,
patchAddressSource,
patchAddressStart);
return(8);
}
patchAddresses[i] = patchAddressStart;
patchSizes[i] = patchAddressEnd - patchAddressStart;
}
File.Copy(inputPath, outputPath, true);
var attributes = File.GetAttributes(outputPath);
if ((attributes & FileAttributes.ReadOnly) != 0)
{
attributes &= ~FileAttributes.ReadOnly;
File.SetAttributes(outputPath, attributes);
}
using (var outputData = File.Open(outputPath, FileMode.Open, FileAccess.ReadWrite))
{
if (addCave == true)
{
outputData.Position = outputData.Length;
var sectionHeadersPosition = outputData.Position;
var newSectionHeaders = new List <Elf.SectionHeader>(inputElf.SectionHeaders);
newSectionHeaders.Add(new Elf.SectionHeader()
{
Name = 0x1C,
Type = Elf.SectionType.Program,
Flags = Elf.SectionFlags.Alloc | Elf.SectionFlags.Executable,
VirtualAddress = caveVirtualAddress,
FileOffset = caveFileOffset,
FileSize = caveFileSize,
Link = 0,
Info = 0,
Align = 4,
EntrySize = 0,
});
foreach (var newSectionHeader in newSectionHeaders)
{
newSectionHeader.Swap();
outputData.WriteStructure(newSectionHeader);
}
// Update section headers info
outputData.Position = Marshal.OffsetOf(typeof(Elf.FileHeader), "SectionHeadersOffset").ToInt64();
outputData.WriteValueS64(sectionHeadersPosition, Endian.Big);
outputData.Position = Marshal.OffsetOf(typeof(Elf.FileHeader), "SectionHeaderCount").ToInt64();
outputData.WriteValueU16((ushort)newSectionHeaders.Count, Endian.Big);
// Update code program info
var programHeaderPosition =
inputElf.FileHeader.ProgramHeadersOffset +
(codeIndex * Marshal.SizeOf(typeof(Elf.ProgramHeader)));
outputData.Position = programHeaderPosition +
Marshal.OffsetOf(typeof(Elf.ProgramHeader), "FileSize").ToInt64();
outputData.WriteValueS64(newCodeSize, Endian.Big);
outputData.Position = programHeaderPosition +
Marshal.OffsetOf(typeof(Elf.ProgramHeader), "MemorySize").ToInt64();
outputData.WriteValueS64(newCodeSize, Endian.Big);
}
for (int i = 0; i < patchCount; i++)
{
var inputOffset = patchElf.GetFileOffset((ulong)patchAddresses[i], (uint)patchSizes[i]);
patchData.Position = inputOffset;
var outputOffset = inputElf.GetFileOffset((ulong)patchAddresses[i], (uint)patchSizes[i]);
outputData.Position = outputOffset;
outputData.WriteFromStream(patchData, patchSizes[i]);
}
}
}
return(0);
}
