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> Windows > ReadFile input name in execution time |
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typedef 30 Apr 2013, 20:27
Hello. When in doubt read the API documentation:
ReadConsole: http://msdn.microsoft.com/en-us/library/windows/desktop/ms684958(v=vs.85).aspx Code: BOOL WINAPI ReadConsole( _In_ HANDLE hConsoleInput, _Out_ LPVOID lpBuffer, _In_ DWORD nNumberOfCharsToRead, _Out_ LPDWORD lpNumberOfCharsRead, _In_opt_ LPVOID pInputControl ); Your buffer points to an 8-byte memory space (x2 DWORD) So you only need to read 7 characters (the last one as a null terminator) or change that to RB 100 (100 bytes) or DB 100 DUP (0) (100 bytes fill with nulls) |
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30 Apr 2013, 20:27 |
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x0r4nd 30 Apr 2013, 21:46
Hello TypeDef tanks about your answer but it do'nt solve the problem.
I think it is not about the size of the buffer because when I add this line Quote: invoke WriteConsole, [out_handle],buf1,[written],[written],0 after the input, it is reproduced without add an extra character or missing information. This occurs regardless of the size or type buffer DD DB TCHAR etc. .. And it remains that: although the typed buffer is received by the perfect form, the file whose name introduced is not open. Code: format PE console 4.0 include 'win32ax.inc' section "data" readable writeable ;FileTitle DB "1.txt" hFile dd ? nSize dd ? lpBytesRead dd ? lpBuffer rb 64000 in_handle DD ? out_handle DD ? written DD ? buf1 rb 100 salto TCHAR 10,13 .code start: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; invoke AllocConsole invoke GetStdHandle, STD_INPUT_HANDLE mov [in_handle], eax invoke GetStdHandle, STD_OUTPUT_HANDLE mov [out_handle], eax ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; proceso: invoke ReadConsole, [in_handle],buf1,6, written, 0 invoke WriteConsole, [out_handle],buf1,[written],[written],0 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; push 0 ;ByVal hTemplateFile As Long push 1 ;ByVal dwFlagsAndAttributes As Long FILE_ATTRIBUTE_READONLY=1 push 3 ;ByVal dwCreationDisposition As Long OPEN_EXISTING=3 push 0 ;ByRef lpSecurityAttributes As SECURITY_ATTRIBUTES push 1 ;ByVal dwShareMode As Long FILE_SHARE_READ=1 push GENERIC_READ ;ByVal dwDesiredAccess As Long push buf1 ;FileTitle ;ByVal lpFileName As String call [CreateFile] ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; mov [hFile], eax invoke GetFileSize,eax, 0; inc eax mov [nSize], eax ; invoke ReadFile,[hFile] , lpBuffer,[nSize], lpBytesRead, 0 ; [nSize] invoke CloseHandle, [hFile] ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; invoke WriteConsole, [out_handle],lpBuffer,[lpBytesRead],[lpBytesRead],0 invoke WriteConsole, [out_handle],salto,2,2,0 ;;;;;;;;;;;;;;;;;;;;;;;;;;;; xor edx,edx mov [buf1],dl mov [lpBytesRead],edx mov [nSize],edx mov [hFile],edx mov [lpBuffer],NULL call proceso invoke ExitProcess, 0 .end start |
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30 Apr 2013, 21:46 |
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hopcode 30 Apr 2013, 22:43
Hallo x0r4nd, try this direct
Code: ;--- usage readfile.exe < readfile.asm ;--- or readfile.exe (echo the line you type, break with Ctrl+C) format PE CONSOLE 5.0 entry start include 'win32a.inc' section '.data' data readable writeable szBuf db 1024 dup (0) szErr db "EOF or error while reading",0 section '.code' code readable executable start: mov edi,szBuf mov esi,szErr .lineN: push edi call [gets] add esp,4 test eax,eax cmovz edi,esi push edi call [strlen] add esp,4 mov dword[edi+eax],0D0Ah push edi call [printf] add esp,4 cmp edi,esi jnz .lineN ret 0 section '.idata' import data readable writeable library \ msvcrt,"MSVCRT",\ import msvcrt,\ printf,"printf",\ gets,"gets",\ strlen,"strlen" example/tuts for c-calling convention without cinvoke ? Cheers,  _________________ ⠓⠕⠏⠉⠕⠙⠑ |
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30 Apr 2013, 22:43 |
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baldr 30 Apr 2013, 22:43
x0r4nd,
Console process gets its own console by default; unless you use FreeConsole() to release it, AllocConsole() will fail. ReadConsole() fills your buffer with available input literally, i.e. <Enter> key will be represented with CR/LF pair. Fourth parameter for WriteConsole() (LPDWORD lpNumberOfCharsWritten) should be address of dword that receives number of characters written; you've passed contents of that dword ([written] instead of written). CreateFile() expects zero-terminated string as contents of memory pointed by LPCTSTR lpFileName parameter. ReadConsole() won't supply that terminator for you. Arbitrary usage of Hungarian prefix notation can be misleading. How your program is supposed to terminate? Apart from GPF or stack overflow, naturally.  |
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30 Apr 2013, 22:43 |
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x0r4nd 30 Apr 2013, 23:40
Hello HopCode, Thank's.
Your code is a very good example of how to enter and read strings in console. But my problem is another: How do I get that string introduced to serve as a file name that wants to open and read in console? I will continue researching, now I do not feel alone. |
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30 Apr 2013, 23:40 |
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x0r4nd 30 Apr 2013, 23:49
Hello Baldr, thank's
I understand and apply your advices, but this did not solve the problem: How do I manually typed the name of a text file that I want to read in the console? I have added the final zero with lstrcat , also with the macro Astrocat (jumpex http://board.flatassembler.net/topic.php?t=11734), but the result is still the same DOES NOT OPEN NOR READ THE FILE. The program is just a sketch, I finish it with ctrl + c, but in the future can enter a key word "exit", "quit", "fin","end", "salir","going out," out "to call ExitProcess. I'm not a hacker, neither a shellcoder ,do not wish to exploit buffers. |
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30 Apr 2013, 23:49 |
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typedef 01 May 2013, 00:43
Study this sir
Code: ; ; (c) 2013. typedef ; include 'win32ax.inc' .data fileNameAsInput db 100 dup(0),0 stdIn dd ? stdOut dd ? _oops db 'AllocConsole failed',0 bytesRead dd ? pBuff db 'Hullo Wurld',0 buff_len = $ - pBuff pszText db 'Enter a file name: ',0 txtLength = $ - pszText bytesWritten dd ? .code start: call [AllocConsole] test eax, eax je .oops ; Get input handle push STD_INPUT_HANDLE call [GetStdHandle] mov [stdIn], eax ; Get output handle push STD_OUTPUT_HANDLE call [GetStdHandle] mov [stdOut], eax ; write somet text push NULL push bytesWritten push txtLength push pszText push [stdOut] call [WriteConsole] ; Read 100 bytes from handle push NULL push bytesRead push 100 push fileNameAsInput push [stdIn] call [ReadConsole] ; trim CRLF mov eax, [bytesRead] add eax, -2 mov [fileNameAsInput+eax], NULL ; Create the file here push NULL push FILE_ATTRIBUTE_NORMAL push CREATE_ALWAYS push NULL push NULL ; exclusive mode push GENERIC_WRITE push fileNameAsInput call [CreateFile] mov ebx, eax ; save file handle ; Write to the file push NULL push bytesRead ; Not needed anymore(bytes written) push buff_len ; number of bytes to write push pBuff push ebx call [WriteFile] ; close the file push ebx call [CloseHandle] ; free the console call [FreeConsole] jmp .finish .oops: push 0 push _oops push _oops push 0 call [MessageBox] .finish: push 0 call [ExitProcess] .end start |
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01 May 2013, 00:43 |
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hopcode 01 May 2013, 00:55
or the same with tomatoes but commented
Code: ;--- fasm readfileA.asm ;--- usage readfileA.exe format PE CONSOLE 5.0 entry start include 'win32a.inc' section '.data' data readable writeable bytesRead dd 0 szBuf db 1024 dup (0) szErr db "Error while reading",0 szMsg db "Please enter a valid filename : ",0 szSize db "Filesize is : %d bytes",13,10,0 szOk db "Ok",13,10,0 section '.code' code readable executable start: xor ebx,ebx push szMsg ;--- print useful message call [printf] add esp,4 ;--- adjust stack here for push once push szBuf ;--- ready to accept a single line containing filename call [gets] add esp,4 test eax,eax jz .err push 0 ;--- template not required push FILE_ATTRIBUTE_NORMAL ;--- normal file push OPEN_EXISTING ;--- how to create push 0 ;--- pointer to security attributes not strictly required push FILE_SHARE_READ \ or FILE_SHARE_WRITE ;--- can be shared push GENERIC_READ ;--- access it for reading push szBuf ;--- filename call [CreateFile] test eax,eax jle .err mov ebx,eax push 0 ;--- file must be < 4Gb push ebx ;--- handle of file to get size of call [GetFileSize] test eax,eax ;--- zero or > 7FFFFFFFh not accepted as size here jle .err push eax push szSize call [printf] add esp,8 ;--- c-calling covention adjust stack for 2 push dword .readN: push 0 ;---address of structure for data push bytesRead ;---address of number of bytes read push 1024 ;---number of bytes to read push szBuf ;---address of buffer that receives data push ebx ;---handle of file to read call [ReadFile] ;--- after a successful read the filepointer is automagically after bytesRead xor ecx,ecx test eax,eax jz .err cmp ecx,[bytesRead] ;--- if bytesRead is 0 we are at EOF jnz .readP push szOk jmp .ok .readP: push szBuf ;--- print content call [printf] add esp,4 jmp .readN .err: push szErr ;--- print error message .ok: call [printf] add esp,4 test ebx,ebx ;--- check if filehandle is ok jz .exit push ebx call [CloseHandle] .exit: ret 0 section '.idata' import data readable writeable library \ kernel32,'KERNEL32',\ msvcrt,"MSVCRT",\ user32,'USER32' include 'api\kernel32.inc' include 'api\user32.inc' import msvcrt,\ printf,"printf",\ gets,"gets",\ strlen,"strlen" after the 3rd post it deserves example/tuts ehh !! _________________ ⠓⠕⠏⠉⠕⠙⠑ |
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01 May 2013, 00:55 |
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baldr 01 May 2013, 01:16
x0r4nd,
Probably you've added final zero to already invalid file name (because it contains CR/LF or is too short. Here is slightly modified version of your source (mods are indicated by ;;;): Code: format PE console 4.0 include 'win32ax.inc' section "data" readable writeable ;FileTitle DB "1.txt" hFile dd ? nSize dd ? lpBytesRead dd ? lpBuffer rb 64000 in_handle DD ? out_handle DD ? written DD ? buf1 rb 100 salto TCHAR 10,13 .code start: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;; invoke AllocConsole invoke GetStdHandle, STD_INPUT_HANDLE mov [in_handle], eax invoke GetStdHandle, STD_OUTPUT_HANDLE mov [out_handle], eax ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; proceso: invoke ReadConsole, [in_handle],buf1,6, written, 0 ;;; invoke WriteConsole, [out_handle],buf1,[written],[written],0 invoke WriteConsole, [out_handle],buf1,[written],written,0 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; push 0 ;ByVal hTemplateFile As Long push 1 ;ByVal dwFlagsAndAttributes As Long FILE_ATTRIBUTE_READONLY=1 push 3 ;ByVal dwCreationDisposition As Long OPEN_EXISTING=3 push 0 ;ByRef lpSecurityAttributes As SECURITY_ATTRIBUTES push 1 ;ByVal dwShareMode As Long FILE_SHARE_READ=1 push GENERIC_READ ;ByVal dwDesiredAccess As Long push buf1 ;FileTitle ;ByVal lpFileName As String call [CreateFile] ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; mov [hFile], eax invoke GetFileSize,eax, 0; inc eax mov [nSize], eax ; invoke ReadFile,[hFile] , lpBuffer,[nSize], lpBytesRead, 0 ; [nSize] invoke CloseHandle, [hFile] ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;; invoke WriteConsole, [out_handle],lpBuffer,[lpBytesRead],[lpBytesRead],0 invoke WriteConsole, [out_handle],lpBuffer,[lpBytesRead],lpBytesRead,0 ;;; invoke WriteConsole, [out_handle],salto,2,2,0 invoke WriteConsole, [out_handle],salto,2,0,0 ;;;;;;;;;;;;;;;;;;;;;;;;;;;; xor edx,edx mov [buf1],dl mov [lpBytesRead],edx mov [nSize],edx mov [hFile],edx mov [lpBuffer],NULL call proceso invoke ExitProcess, 0 .end start Here is another example, it properly terminates entered file name (you may try include "Win32WX.Inc" too, just make sure that your file using UTF-16LE encoding). Code: format PE console
include "Win32AX.Inc"
.code
TypeFile:
invoke GetStdHandle, STD_OUTPUT_HANDLE
mov [hStdOut], eax
invoke WriteConsole, eax, prompt, lengthof.prompt, NULL, NULL
invoke GetStdHandle, STD_INPUT_HANDLE
mov [hStdIn], eax
invoke ReadConsole, eax, filename, lengthof.filename, CharsRead, NULL
mov ecx, [CharsRead]
mov edi, filename
mov eax, 13
if sizeof.TCHAR = 1
repne scas byte [es:edi]
mov byte [edi-sizeof.TCHAR], 0
else if sizeof.TCHAR = 2
repne scas word [es:edi]
mov word [edi-sizeof.TCHAR], 0
else
err "Unknown character size"
end if
invoke CreateFile, filename, GENERIC_READ, FILE_SHARE_READ, NULL,\
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL+FILE_FLAG_SEQUENTIAL_SCAN, NULL
mov [hFile], eax
invoke ReadFile, eax, buffer, sizeof.buffer, BytesRead, NULL
invoke CloseHandle, [hFile]
mov eax, [BytesRead]
if sizeof.TCHAR = 2
shr eax, 1
end if
invoke WriteConsole, [hStdOut], buffer, eax, NULL, NULL
invoke ExitProcess, 0
.data
prompt TCHAR "Enter file name: "
lengthof.prompt = ($ - prompt)/sizeof.TCHAR
hStdIn dd ?
hStdOut dd ?
CharsRead dd ?
filename TCHAR MAX_PATH dup ?
lengthof.filename = ($ - filename)/sizeof.TCHAR
hFile dd ?
BytesRead dd ?
buffer TCHAR 1000 dup ?
sizeof.buffer = $ - buffer
.end TypeFile |
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01 May 2013, 01:16 |
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x0r4nd 01 May 2013, 01:47
Thank you all.
I will study the examples; for now, the Hopcode's code works perfectly. The others has not yet managed to work. I will do the home work. As I said earlier, the problem was elementary and only product of my ignorance. Thanks a lot again. |
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01 May 2013, 01:47 |
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