public static TraceState InstallTracer(Process process, ulong patchSite, Logger logger, byte[] asmSizes, ImportResolver ir)
{
var processHandle = Win32Imports.OpenProcess(Win32Imports.ProcessAccessFlags.All, false, process.Id);
var traceState = new TraceState();
if ((ulong)processHandle == 0)
{
logger.WriteLine("could not open process");
return(null);
}
const int patchSiteSize = 24;
const int codeSize = 1024;
const int traceLogSize = 1024;
var originalCode = DebugProcessUtils.ReadBytes(process, (ulong)process.MainModule.BaseAddress, process.MainModule.ModuleMemorySize);
var originalCodeAddress = Win32Imports.VirtualAllocEx(
processHandle,
new IntPtr(0),
new IntPtr(originalCode.Length),
Win32Imports.AllocationType.Commit | Win32Imports.AllocationType.Reserve,
Win32Imports.MemoryProtection.ReadWrite);
if ((ulong)originalCodeAddress == 0)
{
logger.WriteLine($"could not allocate memory for {nameof(originalCodeAddress)}");
return(null);
}
var traceLogAddress = Win32Imports.VirtualAllocEx(
processHandle,
new IntPtr(0),
new IntPtr(traceLogSize),
Win32Imports.AllocationType.Commit | Win32Imports.AllocationType.Reserve,
Win32Imports.MemoryProtection.ReadWrite);
if ((ulong)traceLogAddress == 0)
{
logger.WriteLine($"could not allocate memory for {nameof(traceLogAddress)}");
return(null);
}
var injectedCodeAddress = Win32Imports.VirtualAllocEx(
processHandle,
new IntPtr(0),
new IntPtr(codeSize),
Win32Imports.AllocationType.Commit | Win32Imports.AllocationType.Reserve,
Win32Imports.MemoryProtection.ExecuteReadWrite);
if ((ulong)injectedCodeAddress == 0)
{
logger.WriteLine($"could not allocate memory for {nameof(injectedCodeAddress)}");
return(null);
}
var asmSizesAddress = Win32Imports.VirtualAllocEx(
processHandle,
new IntPtr(0),
new IntPtr(asmSizes.Length),
Win32Imports.AllocationType.Commit | Win32Imports.AllocationType.Reserve,
Win32Imports.MemoryProtection.ReadWrite);
if ((ulong)asmSizesAddress == 0)
{
logger.WriteLine($"could not allocate memory for {nameof(asmSizesAddress)}");
return(null);
}
traceState.CodeAddress = (ulong)injectedCodeAddress;
traceState.TraceLogAddress = (ulong)traceLogAddress;
int addrSize = Marshal.SizeOf(typeof(IntPtr));
var c1 = Assembler.CreateContext <Action>();
// save rax
c1.Push(c1.Rax);
// push return address
c1.Lea(c1.Rax, Memory.QWord(CodeContext.Rip, -addrSize));
c1.Push(c1.Rax);
// push "call" address
c1.Mov(c1.Rax, (ulong)injectedCodeAddress);
c1.Push(c1.Rax);
// "call" codeAddress
c1.Ret();
c1.Nop();
c1.Nop();
c1.Nop();
var patchSiteCodeJit = AssemblyUtil.GetAsmJitBytes(c1);
Debug.Assert(patchSiteCodeJit.Length == patchSiteSize, "patch site size incorrect");
var c = Assembler.CreateContext <Action>();
c.Push(c.Rbp);
c.Mov(c.Rbp, c.Rsp);
c.Pushf();
c.Push(c.Rbx);
c.Push(c.Rcx);
c.Push(c.Rdx);
// log thread id
var getThreadContext = ir.LookupFunction("KERNEL32.DLL:GetCurrentThreadId");
//c.Call(getThreadContext);
c.Lea(c.Rax, Memory.QWord(CodeContext.Rip, 13)); // skips next instructions
c.Push(c.Rax);
c.Mov(c.Rax, getThreadContext);
c.Push(c.Rax);
c.Ret();
c.Mov(c.Rbx, (ulong)traceLogAddress);
c.Mov(Memory.Word(c.Rbx), c.Eax);
// reserve space for instruction counter, the 01-08 is just so AsmJit doesn't shorten the instruction
// we overwrite the value to 0 later on
c.Mov(c.Rax, (ulong)0x0102030405060708);
var smcLastRipJit = AssemblyUtil.GetAsmJitBytes(c).Length - addrSize;
c.Lea(c1.Rax, Memory.QWord(CodeContext.Rip, -7 - addrSize));
c.Mov(c.Rcx, Memory.QWord(c.Rax));
c.Inc(c.Rcx);
c.Xchg(Memory.QWord(c.Rax), c.Rcx);
// find return address and store size of instruction at return address in rcx
c.Mov(c.Rdx, Memory.QWord(c.Rbp, addrSize));
c.Mov(c.Rbx, c.Rdx);
c.Mov(c.Rax, (ulong)process.MainModule.BaseAddress);
c.Sub(c.Rdx, c.Rax);
c.Mov(c.Rax, (ulong)asmSizesAddress);
c.Add(c.Rdx, c.Rax);
c.Movzx(c.Rcx, Memory.Byte(c.Rdx));
// RESTORE ORIGINAL CODE
// get address of original code in Rdx
c.Mov(c.Rdx, c.Rbx);
c.Mov(c.Rax, (ulong)process.MainModule.BaseAddress);
c.Sub(c.Rdx, c.Rax);
// TODO: compare Rdx with process.MainModule.ModuleMemorySize - patchSiteSize and abort if greater
c.Mov(c.Rax, (ulong)originalCodeAddress);
c.Add(c.Rdx, c.Rax);
// restore call site 1
c.Mov(c.Rax, Memory.QWord(c.Rdx));
c.Mov(Memory.QWord(c.Rbx), c.Rax);
// restore call site 2
c.Mov(c.Rax, Memory.QWord(c.Rdx, addrSize));
c.Mov(Memory.QWord(c.Rbx, addrSize), c.Rax);
// restore call site 3
c.Mov(c.Rax, Memory.QWord(c.Rdx, addrSize * 2));
c.Mov(Memory.QWord(c.Rbx, addrSize * 2), c.Rax);
// CLEAN UP AND RETURN
// put new patch in place
// add instruction size to return address, so we write patch at next instruction
c.Add(c.Rbx, c.Rcx);
// restore patch site 1
c.Mov(c.Rax, BitConverter.ToUInt64(patchSiteCodeJit, 0));
c.Mov(Memory.QWord(c.Rbx), c.Rax);
// restore patch site 2
c.Mov(c.Rax, BitConverter.ToUInt64(patchSiteCodeJit, addrSize));
c.Mov(Memory.QWord(c.Rbx, addrSize), c.Rax);
// restore patch site 3
c.Mov(c.Rax, BitConverter.ToUInt64(patchSiteCodeJit, addrSize * 2));
c.Mov(Memory.QWord(c.Rbx, addrSize * 2), c.Rax);
// end put new patch in place
// restore rax from call site
c.Mov(c.Rax, Memory.QWord(c.Rbp, 2 * addrSize));
c.Pop(c.Rdx);
c.Pop(c.Rcx);
c.Pop(c.Rbx);
c.Popf();
c.Pop(c.Rbp);
c.Ret((ulong)8);
// overwrite some pieces of the code with values computed later on
var codeSiteCodeJit = AssemblyUtil.GetAsmJitBytes(c);
for (var j = 0; j < 8; j++)
{
codeSiteCodeJit[smcLastRipJit + j] = 0;
}
var i = 0;
var nextOffset1 = 0;
using (var sw = new StreamWriter(Specifics.PatchAsmDumpFileName)) {
foreach (var s in codeSiteCodeJit.Select((b1) => $"b: 0x{b1:X2}"))
{
string asm1S;
try {
var asm1 = AssemblyUtil.Disassemble(codeSiteCodeJit.Skip(i).Take(AssemblyUtil.MaxInstructionBytes).ToArray());
asm1S = i == nextOffset1?asm1.ToString() : "";
if (i == nextOffset1)
{
nextOffset1 += asm1.Length;
}
}
catch (DecodeException) {
asm1S = "failed";
}
sw.WriteLine($"{s}: ASM: {asm1S}");
i++;
}
}
if (codeSiteCodeJit.Length > codeSize)
{
throw new Exception("did not reserve enough memory for code");
}
// write process memory
DebugProcessUtils.WriteBytes(process, (ulong)originalCodeAddress, originalCode);
DebugProcessUtils.WriteBytes(process, (ulong)asmSizesAddress, asmSizes);
DebugProcessUtils.WriteBytes(process, (ulong)injectedCodeAddress, codeSiteCodeJit);
DebugProcessUtils.WriteBytes(process, patchSite, patchSiteCodeJit);
return(traceState);
}
public static void InstallTracer(Process process, ulong patchSite, Logger logger)
{
var processHandle = Win32Imports.OpenProcess(Win32Imports.ProcessAccessFlags.All, false, process.Id);
var retVal = new TraceState();
if ((ulong)processHandle == 0)
{
logger.WriteLine("could not open process");
return;
}
const int patchSiteSize = 24;
const int patchAreaSize = 100;
const int codeSize = 1024 + patchAreaSize * 100;
var originalCode = DebugProcessUtils.ReadBytes(process, patchSite, patchAreaSize);
// minus patchSiteSize because we need to restore patchSiteSize bytes
var ci = new diStorm.CodeInfo(0, originalCode.Take(patchAreaSize - patchSiteSize).ToArray(), diStorm.DecodeType.Decode64Bits, 0);
var dr = new diStorm.DecodedResult(patchAreaSize);
diStorm.diStorm3.Decode(ci, dr);
var decodedInstructions = dr.Instructions;
var bogusAddress = Win32Imports.VirtualAllocEx(
processHandle,
new IntPtr(0),
new IntPtr(patchSiteSize * 2),
Win32Imports.AllocationType.Commit | Win32Imports.AllocationType.Reserve,
Win32Imports.MemoryProtection.ReadWrite);
var codeAddress = Win32Imports.VirtualAllocEx(
processHandle,
new IntPtr(0),
new IntPtr(codeSize),
Win32Imports.AllocationType.Commit | Win32Imports.AllocationType.Reserve,
Win32Imports.MemoryProtection.ExecuteReadWrite);
retVal.CodeAddress = (ulong)codeAddress;
if ((ulong)codeAddress == 0)
{
logger.WriteLine("could not allocate memory");
return;
}
var patchSiteCode = new byte[patchSiteSize];
var codeSiteCode = new byte[codeSize];
var patchPtr = 0;
var ptr = 0;
//patchSiteCode[patchPtr++] = 0xCC;
// push rax, see RESTORE_RAX
patchSiteCode[patchPtr++] = 0x50;
// lea rax, [rip-8]
patchSiteCode[patchPtr++] = 0x48;
patchSiteCode[patchPtr++] = 0x8D;
patchSiteCode[patchPtr++] = 0x05;
patchSiteCode[patchPtr++] = 0xF8;
patchSiteCode[patchPtr++] = 0xFF;
patchSiteCode[patchPtr++] = 0xFF;
patchSiteCode[patchPtr++] = 0xFF;
// push rax (rip)
patchSiteCode[patchPtr++] = 0x50;
// mov rax, constant
patchSiteCode[patchPtr++] = 0x48;
patchSiteCode[patchPtr++] = 0xB8;
foreach (var b in BitConverter.GetBytes((ulong)codeAddress))
{
patchSiteCode[patchPtr++] = b;
}
// push rax
patchSiteCode[patchPtr++] = 0x50;
// ret
patchSiteCode[patchPtr++] = 0xC3;
patchPtr += 3;
if (patchPtr != patchSiteSize)
{
logger.WriteLine($"made a mistake: {patchPtr} != {patchSiteSize}");
return;
}
// push rbp
codeSiteCode[ptr++] = 0x55;
// mov rbp, rsp
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x89;
codeSiteCode[ptr++] = 0xE5;
// push flags
codeSiteCode[ptr++] = 0x9C;
// push rbx
codeSiteCode[ptr++] = 0x53;
// push rcx
codeSiteCode[ptr++] = 0x51;
// push rdx
codeSiteCode[ptr++] = 0x52;
// reserve space for last Rip address
// mov rax, constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0xB8;
var smcLastRip = ptr;
ptr += 8;
// lea rax, [rip-7-8]
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x8D;
codeSiteCode[ptr++] = 0x05;
codeSiteCode[ptr++] = 0xF1;
codeSiteCode[ptr++] = 0xFF;
codeSiteCode[ptr++] = 0xFF;
codeSiteCode[ptr++] = 0xFF;
// mov rcx, [rax]
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x8B;
codeSiteCode[ptr++] = 0x08;
// inc rcx
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0xFF;
codeSiteCode[ptr++] = 0xC1;
// xchg [rax], rcx
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x87;
codeSiteCode[ptr++] = 0x08;
// find return address
// mov rbx, [rbp+8]
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x8B;
codeSiteCode[ptr++] = 0x5D;
codeSiteCode[ptr++] = 0x08;
// call pastEndCode
codeSiteCode[ptr++] = 0xE8;
var callPastEndCodeImmediate = ptr;
ptr += 4;
var callPastEndCodeBaseOffset = ptr;
// END FUNCTION
// put new patch in place
// mov rax, constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0xB8;
foreach (var b in patchSiteCode.Skip(0).Take(8))
{
codeSiteCode[ptr++] = b;
}
// restore patch site 1
// mov [rbx], rax
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x89;
codeSiteCode[ptr++] = 0x03;
// mov rax, constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0xB8;
foreach (var b in patchSiteCode.Skip(8).Take(8))
{
codeSiteCode[ptr++] = b;
}
// restore patch site 2
// mov [rbx+8], rax
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x89;
codeSiteCode[ptr++] = 0x43;
codeSiteCode[ptr++] = 0x08;
// mov rax, constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0xB8;
foreach (var b in patchSiteCode.Skip(16).Take(8))
{
codeSiteCode[ptr++] = b;
}
// restore patch site 3
// mov [rbx+16], rax
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x89;
codeSiteCode[ptr++] = 0x43;
codeSiteCode[ptr++] = 0x10;
// end put new patch in place
// mov rax,[rbp+16]
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x8B;
codeSiteCode[ptr++] = 0x45;
codeSiteCode[ptr++] = 0x10;
// pop rdx
codeSiteCode[ptr++] = 0x5A;
// pop rcx
codeSiteCode[ptr++] = 0x59;
// pop rbx
codeSiteCode[ptr++] = 0x5B;
// pop flags
codeSiteCode[ptr++] = 0x9D;
// pop rbp
codeSiteCode[ptr++] = 0x5D;
// ret 8
codeSiteCode[ptr++] = 0xC2;
codeSiteCode[ptr++] = 0x08;
codeSiteCode[ptr++] = 0x00;
codeSiteCode[callPastEndCodeImmediate] = (byte)(ptr - callPastEndCodeBaseOffset);
// imul rcx,rcx,constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x6B;
codeSiteCode[ptr++] = 0xC9;
// = size of restore function
var multiplyImmediate = ptr;
codeSiteCode[ptr++] = 0x00;
// lea rcx, rcx+eax+constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x8D;
codeSiteCode[ptr++] = 0x4C;
codeSiteCode[ptr++] = 0x08;
var leaRcxConstant = ptr;
codeSiteCode[ptr++] = 0x00;
// jmp rcx
codeSiteCode[ptr++] = 0xFF;
codeSiteCode[ptr++] = 0xE1;
codeSiteCode[leaRcxConstant] = (byte)(ptr - smcLastRip);
// restore function
uint offset = 0;
var lastReturn = 0;
foreach (var instr in decodedInstructions.Select((value, index) => new { Value = value, Index = index }))
{
var startOfRestore = ptr;
Console.WriteLine($"instruction {instr.Value.Mnemonic}, size: {instr.Value.Size}");
// reserve space for call site restore 1
// mov rax, constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0xB8;
var originalOffset = 0;
var patchOffset = 0;
foreach (var b in originalCode.Skip((int)offset).Take(8))
{
if (originalOffset < instr.Value.Size)
{
codeSiteCode[ptr++] = b;
}
else
{
codeSiteCode[ptr++] = patchSiteCode[patchOffset++];
}
originalOffset++;
}
// restore call site 1
// mov [rbx], rax
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x89;
codeSiteCode[ptr++] = 0x03;
// reserve space for call site restore 2
// mov rax, constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0xB8;
foreach (var b in originalCode.Skip((int)offset + 8).Take(8))
{
if (originalOffset < instr.Value.Size)
{
codeSiteCode[ptr++] = b;
}
else
{
codeSiteCode[ptr++] = patchSiteCode[patchOffset++];
}
originalOffset++;
}
// restore call site 2
// mov [rbx+8], rax
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x89;
codeSiteCode[ptr++] = 0x43;
codeSiteCode[ptr++] = 0x08;
// reserve space for call site restore 3
// mov rax, constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0xB8;
foreach (var b in originalCode.Skip((int)offset + 16).Take(8))
{
if (originalOffset < instr.Value.Size)
{
codeSiteCode[ptr++] = b;
}
else
{
codeSiteCode[ptr++] = patchSiteCode[patchOffset++];
}
originalOffset++;
}
// restore call site 3
// mov [rbx+16], rax
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x89;
codeSiteCode[ptr++] = 0x43;
codeSiteCode[ptr++] = 0x10;
// prepare rbx to put new patch in place
// add rbx,instrSize
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0x83;
codeSiteCode[ptr++] = 0xC3;
codeSiteCode[ptr++] = (byte)(instr.Value.Size);
// return
lastReturn = ptr;
codeSiteCode[ptr++] = 0xC3;
var endOfRestore = ptr;
Console.WriteLine($"mul: {endOfRestore - startOfRestore}");
codeSiteCode[multiplyImmediate] = (byte)(endOfRestore - startOfRestore);
offset += instr.Value.Size;
}
ptr = lastReturn;
// we set rbx to bogus so that patch is not written for last instruction in set
// mov rbx, constant
codeSiteCode[ptr++] = 0x48;
codeSiteCode[ptr++] = 0xBB;
foreach (var b in BitConverter.GetBytes((ulong)bogusAddress))
{
codeSiteCode[ptr++] = b;
}
// return
codeSiteCode[ptr] = 0xC3;
DebugProcessUtils.WriteBytes(process, (ulong)codeAddress, codeSiteCode);
DebugProcessUtils.WriteBytes(process, patchSite, patchSiteCode);
}
