从内存中加载DLL Delphi版(转)

源：从内存中加载DLL DELPHI版

原文 ： http://www.2ccc.com/article.asp?articleid=5784

MemLibrary.pas

//从内存中加载DLL DELPHI版  
unit MemLibrary;interfaceuses
Windows;function memLoadLibrary(pLib: Pointer): DWord;
function memGetProcAddress(dwLibHandle: DWord; pFunctionName: PChar): Pointer; stdcall;
function memFreeLibrary(dwHandle: DWord): Boolean;implementationprocedure ChangeReloc(baseorgp, basedllp, relocp: pointer; size: cardinal);
typeTRelocblock = recordvaddress: integer;size: integer;end;PRelocblock = ^TRelocblock;
varmyreloc: PRelocblock;reloccount: integer;startp: ^word;i: cardinal;p: ^cardinal;dif: cardinal;
beginmyreloc := relocp;dif := cardinal(basedllp)-cardinal(baseorgp);startp := pointer(cardinal(relocp)+8);while myreloc^.vaddress <> 0 dobeginreloccount := (myreloc^.size-8) div sizeof(word);for i := 0 to reloccount-1 dobeginif (startp^ xor $3000 < $1000) thenbeginp := pointer(myreloc^.vaddress+startp^ mod $3000+integer(basedllp));p^ := p^+dif;end;startp := pointer(cardinal(startp)+sizeof(word));end;myreloc := pointer(startp);startp := pointer(cardinal(startp)+8);end;
end;
procedure CreateImportTable(dllbasep, importp: pointer); stdcall;
typetimportblock = recordCharacteristics: cardinal;TimeDateStamp: cardinal;ForwarderChain: cardinal;Name: pchar;FirstThunk: pointer;end;pimportblock = ^timportblock;
varmyimport: pimportblock;thunksread, thunkswrite: ^pointer;dllname: pchar;dllh: thandle;old: cardinal;
beginmyimport := importp;while (myimport^.FirstThunk <> nil) and (myimport^.Name <> nil) dobegindllname := pointer(integer(dllbasep)+integer(myimport^.name));dllh := LoadLibrary(dllname);thunksread := pointer(integer(myimport^.FirstThunk)+integer(dllbasep));thunkswrite := thunksread;if integer(myimport^.TimeDateStamp) = -1 thenthunksread := pointer(integer(myimport^.Characteristics)+integer(dllbasep));while (thunksread^ <> nil) dobeginif VirtualProtect(thunkswrite,4,PAGE_EXECUTE_READWRITE,old) thenbeginif (cardinal(thunksread^) and $80000000 <> 0) thenthunkswrite^ := GetProcAddress(dllh,pchar(cardinal(thunksread^) and $FFFF)) elsethunkswrite^ := GetProcAddress(dllh,pchar(integer(dllbasep)+integer(thunksread^)+2));VirtualProtect(thunkswrite,4,old,old);end;inc(thunksread,1);inc(thunkswrite,1);end;myimport := pointer(integer(myimport)+sizeof(timportblock));end;
end;function memLoadLibrary(pLib: Pointer): DWord;
var
DllMain    : function (dwHandle, dwReason, dwReserved: DWord): DWord; stdcall;
IDH        : PImageDosHeader;
INH        : PImageNtHeaders;
SEC        : PImageSectionHeader;
dwSecCount : DWord;
dwLen      : DWord;
dwmemsize : DWord;
i          : Integer;
pAll       : Pointer;
begin
Result := 0;IDH := pLib;
if isBadReadPtr(IDH, SizeOf(TImageDosHeader)) or (IDH^.e_magic <> IMAGE_DOS_SIGNATURE) thenExit;INH := pointer(cardinal(pLib)+cardinal(IDH^._lfanew));
if isBadReadPtr(INH, SizeOf(TImageNtHeaders)) or (INH^.Signature <> IMAGE_NT_SIGNATURE) thenExit;// if (pReserved <> nil) then
//    dwLen := Length(pReserved)+1
// elsedwLen := 0;SEC := Pointer(Integer(INH)+SizeOf(TImageNtHeaders));
dwMemSize := INH^.OptionalHeader.SizeOfImage;
if (dwMemSize = 0) then Exit;pAll := VirtualAlloc(nil,dwMemSize+dwLen,MEM_COMMIT or MEM_RESERVE,PAGE_EXECUTE_READWRITE);
if (pAll = nil) then Exit;dwSecCount := INH^.FileHeader.NumberOfSections;
CopyMemory(pAll,IDH,DWord(SEC)-DWord(IDH)+dwSecCount*SizeOf(TImageSectionHeader));
// CopyMemory(Pointer(DWord(pAll) + dwMemSize),pReserved,dwLen-1);
CopyMemory(Pointer(DWord(pAll) + dwMemSize),nil,dwLen-1);
for i := 0 to dwSecCount-1 do
beginCopyMemory(Pointer(DWord(pAll)+SEC^.VirtualAddress),Pointer(DWord(pLib)+DWord(SEC^.PointerToRawData)),SEC^.SizeOfRawData);SEC := Pointer(Integer(SEC)+SizeOf(TImageSectionHeader));
end;if (INH^.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC].VirtualAddress <> 0) thenChangeReloc(Pointer(INH^.OptionalHeader.ImageBase),pAll,Pointer(DWord(pAll)+INH^.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC].VirtualAddress),INH^.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC].Size);
CreateImportTable(pAll, Pointer(DWord(pAll)+INH^.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress));@DllMain := Pointer(INH^.OptionalHeader.AddressOfEntryPoint+DWord(pAll));
// if (INH^.OptionalHeader.AddressOfEntryPoint <> 0) and (bDllMain) then
if INH^.OptionalHeader.AddressOfEntryPoint <> 0 then
begintry
//      if (pReserved <> nil) then
//        DllMain(DWord(pAll),DLL_PROCESS_ATTACH,DWord(pAll)+dwMemSize)
//      elseDllMain(DWord(pAll),DLL_PROCESS_ATTACH,0);exceptend;
end;
Result := DWord(pAll);
end;function memFreeLibrary(dwHandle: DWord): Boolean;
var
IDH: PImageDosHeader;
INH: PImageNTHeaders;
begin
Result := false;
if (dwHandle = 0) thenExit;IDH := Pointer(dwHandle);
if (IDH^.e_magic <> IMAGE_DOS_SIGNATURE) thenExit;INH := Pointer(DWord(IDH^._lfanew)+DWord(IDH));
if (INH^.Signature <> IMAGE_NT_SIGNATURE) thenExit;if VirtualFree(Pointer(dwHandle),INH^.OptionalHeader.SizeOfImage,MEM_DECOMMIT) thenResult := True;
end;function memGetProcAddress(dwLibHandle: DWord; pFunctionName: PChar): Pointer; stdcall;
var
NtHeader          : PImageNtHeaders;
DosHeader          : PImageDosHeader;
DataDirectory      : PImageDataDirectory;
ExportDirectory    : PImageExportDirectory;
i          : Integer;
iExportOrdinal     : Integer;
ExportName         : String;
dwPosDot          : DWord;
dwNewmodule        : DWord;
pFirstExportName   : Pointer;
pFirstExportAddress: Pointer;
pFirstExportOrdinal: Pointer;
pExportAddr        : PDWord;
pExportNameNow     : PDWord;
pExportOrdinalNow : PWord;
begin
Result := nil;
if pFunctionName = nil then Exit;DosHeader := Pointer(dwLibHandle);
if isBadReadPtr(DosHeader,sizeof(TImageDosHeader)) or (DosHeader^.e_magic <> IMAGE_DOS_SIGNATURE) thenExit; {Wrong PE (DOS) Header}NtHeader := Pointer(DWord(DosHeader^._lfanew)+DWord(DosHeader));
if isBadReadPtr(NtHeader, sizeof(TImageNTHeaders)) or (NtHeader^.Signature <> IMAGE_NT_SIGNATURE) thenExit; {Wrong PW (NT) Header}DataDirectory := @NtHeader^.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT];
if (DataDirectory = nil) or (DataDirectory^.VirtualAddress = 0) thenExit; {Library has no exporttable}ExportDirectory := Pointer(DWord(DosHeader) + DWord(DataDirectory^.VirtualAddress));
if isBadReadPtr(ExportDirectory,SizeOf(TImageExportDirectory)) thenExit;pFirstExportName := Pointer(DWord(ExportDirectory^.AddressOfNames)+DWord(DosHeader));
pFirstExportOrdinal := Pointer(DWord(ExportDirectory^.AddressOfNameOrdinals)+DWord(DosHeader));
pFirstExportAddress := Pointer(DWord(ExportDirectory^.AddressOfFunctions)+DWord(DosHeader));if (integer(pFunctionName) > $FFFF) then {is FunctionName a PChar?}
beginiExportOrdinal := -1;          {if we dont find the correct ExportOrdinal}for i := 0 to ExportDirectory^.NumberOfNames-1 do {for each export do}beginpExportNameNow := Pointer(Integer(pFirstExportName)+SizeOf(Pointer)*i);if (not isBadReadPtr(pExportNameNow,SizeOf(DWord))) thenbeginExportName := PChar(pExportNameNow^+ DWord(DosHeader));if (ExportName = pFunctionName) then {is it the export we search? Calculate the ordinal.}beginpExportOrdinalNow := Pointer(Integer(pFirstExportOrdinal)+SizeOf(Word)*i);if (not isBadReadPtr(pExportOrdinalNow,SizeOf(Word))) theniExportOrdinal := pExportOrdinalNow^;end;end;end;
end else{no PChar, calculate the ordinal directly}iExportOrdinal := DWord(pFunctionName)-DWord(ExportDirectory^.Base);if (iExportOrdinal < 0) or (iExportOrdinal > Integer(ExportDirectory^.NumberOfFunctions)) thenExit; {havent found the ordinal}pExportAddr := Pointer(iExportOrdinal*4+Integer(pFirstExportAddress));
if (isBadReadPtr(pExportAddr,SizeOf(DWord))) thenExit;{Is the Export outside the ExportSection? If not its NT spezific forwared function}
if (pExportAddr^ < DWord(DataDirectory^.VirtualAddress)) or(pExportAddr^ > DWord(DataDirectory^.VirtualAddress+DataDirectory^.Size)) then
beginif (pExportAddr^ <> 0) then {calculate export address}Result := Pointer(pExportAddr^+DWord(DosHeader));
end
else
begin {forwarded function (like kernel32.EnterCriticalSection -> NTDLL.RtlEnterCriticalSection)}ExportName := PChar(dwLibHandle+pExportAddr^);dwPosDot := Pos('.',ExportName);if (dwPosDot > 0) thenbegindwNewModule := GetModuleHandle(PChar(Copy(ExportName,1,dwPosDot-1)));if (dwNewModule = 0) thendwNewModule := LoadLibrary(PChar(Copy(ExportName,1,dwPosDot-1)));if (dwNewModule <> 0) thenresult := GetProcAddressX(dwNewModule,PChar(Copy(ExportName,dwPosDot+1,Length(ExportName))));end;
end;
end;end.