I already asked a similar question, "PE Header requirements", but I'm not really satisfied with it's answer.
I am building an assembler/linker, in Java SE 1.6. I have read about 5 different documentations/specifications about the PE/COFF header and file format, but I'm stuck at a problem:
My generated file is not valid, says Windows: "X is not a valid Win32 application." I'm clueless of what can be wrong; I have double-checked every entry in the PE Header and PE Optional Header, and all seems to be right.
I've got three sections:
code (RVA 0x1000, File 0x400)data (RVA 0x2000, File 0x600)import (RVA 0x3000, File 0x800)My entrypoint value is at 0x1000 (the beginning of code) and my imagebase is 0x400000. Section alignment is 0x1000 and file alignment is 0x200.
See the revisions of this question to see the whole file.
So: I grabbed a valid PE file (a simple "Hello World" message box application), and started to modify it, with a hex-editor (HxD). I got a lot of different error messages, not the "X is not a valid Win32 application.":
I'm aware that my code content is not "valid" code, but I've tested it out: invalid code gives an Application Crash error.
If the import-section content is invalid in the "Hello World" PE file, it gives me the error "Procedure point cannot be found in [...]", or "Application has failed to start because [..] dll is not found.", or an Application Crash. These errors are all very useful; they all give me some clue what was wrong.
But my PE file, with the error "X is not a valid Win32 application.", drives me insane: What is wrong with my PE file?
Dumpbin output:
E:\Documenten\CP Language\compiler\Win32Builder>dumpbin /ALL test.exe
Microsoft (R) COFF/PE Dumper Version 10.00.21003.01
Copyright (C) Microsoft Corporation. All rights reserved.
Dump of file test.exe
PE signature found
File Type: EXECUTABLE IMAGE
FILE HEADER VALUES
14C machine (x86)
3 number of sections
32EB4BF5 time date stamp Sun Jan 26 13:20:05 1997
0 file pointer to symbol table
0 number of symbols
E0 size of optional header
703 characteristics
Relocations stripped
Executable
32 bit word machine
Debug information stripped
CD - run from swapfile
OPTIONAL HEADER VALUES
10B magic # (PE32)
8.00 linker version
1000 size of code
1000 size of initialized data
0 size of uninitialized data
1000 entry point (00401000)
1000 base of code
2000 base of data
400000 image base (00400000 to 0040088F)
1000 section alignment
200 file alignment
4.00 operating system version
13.37 image version
4.00 subsystem version
0 Win32 version
890 size of image
400 size of headers
0 checksum
2 subsystem (Windows GUI)
0 DLL characteristics
40000 size of stack reserve
11000 size of stack commit
100000 size of heap reserve
1000 size of heap commit
0 loader flags
10 number of directories
0 [ 0] RVA [size] of Export Directory
3000 [ 1000] RVA [size] of Import Directory
0 [ 0] RVA [size] of Resource Directory
0 [ 0] RVA [size] of Exception Directory
0 [ 0] RVA [size] of Certificates Directory
0 [ 0] RVA [size] of Base Relocation Directory
0 [ 0] RVA [size] of Debug Directory
0 [ 0] RVA [size] of Architecture Directory
0 [ 0] RVA [size] of Global Pointer Directory
0 [ 0] RVA [size] of Thread Storage Directory
0 [ 0] RVA [size] of Load Configuration Directory
0 [ 0] RVA [size] of Bound Import Directory
0 [ 0] RVA [size] of Import Address Table Directory
0 [ 0] RVA [size] of Delay Import Directory
0 [ 0] RVA [size] of COM Descriptor Directory
0 [ 0] RVA [size] of Reserved Directory
SECTION HEADER #1
.code name
1000 virtual size
1000 virtual address (00401000 to 00401FFF)
23 size of raw data
400 file pointer to raw data (00000400 to 00000422)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
60000020 flags
Code
Execute Read
RAW DATA #1
00401000: 68 00 00 00 00 68 0D 20 40 00 68 00 20 40 00 68 h....h. @.h. @.h
00401010: 00 00 00 00 E8 64 30 40 00 68 00 00 00 00 E8 6C ....èd0@.h....èl
00401020: 30 40 00 0@.
SECTION HEADER #2
.data name
1000 virtual size
2000 virtual address (00402000 to 00402FFF)
23 size of raw data
600 file pointer to raw data (00000600 to 00000622)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0000040 flags
Initialized Data
Read Write
RAW DATA #2
00402000: 48 65 6C 6C 6F 20 57 6F 72 6C 64 21 00 48 65 6C Hello World!.Hel
00402010: 6C 6F 20 53 74 61 63 6B 20 4F 76 65 72 66 6C 6F lo Stack Overflo
00402020: 77 21 00 w!.
SECTION HEADER #3
.import name
1000 virtual size
3000 virtual address (00403000 to 00403FFF)
90 size of raw data
800 file pointer to raw data (00000800 to 0000088F)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
50000040 flags
Initialized Data
Shared
Read Only
RAW DATA #3
00403000: 54 30 00 00 00 00 00 00 00 00 00 00 3C 30 00 00 T0..........<0..
00403010: 64 30 00 00 5C 30 00 00 00 00 00 00 00 00 00 00 d0..\0..........
00403020: 47 30 00 00 6C 30 00 00 00 00 00 00 00 00 00 00 G0..l0..........
00403030: 00 00 00 00 00 00 00 00 00 00 00 00 75 73 65 72 ............user
00403040: 33 32 2E 64 6C 6C 00 6B 65 72 6E 65 6C 33 32 2E 32.dll.kernel32.
00403050: 64 6C 6C 00 74 30 00 00 00 00 00 00 82 30 00 00 dll.t0.......0..
00403060: 00 00 00 00 74 30 00 00 00 00 00 00 82 30 00 00 ....t0.......0..
00403070: 00 00 00 00 00 00 4D 65 73 73 61 67 65 42 6F 78 ......MessageBox
00403080: 41 00 00 00 45 78 69 74 50 72 6F 63 65 73 73 00 A...ExitProcess.
Section contains the following imports:
user32.dll
403064 Import Address Table
403054 Import Name Table
0 time date stamp
0 Index of first forwarder reference
0 MessageBoxA
kernel32.dll
40306C Import Address Table
40305C Import Name Table
0 time date stamp
0 Index of first forwarder reference
0 ExitProcess
Summary
1000 .code
1000 .data
1000 .import
The Size Of Image is, according to dumpbin 890, while it should be the size of image in the memory, i.e. the latest section's RVA + that section's rounded-up size (e.g. 0x5000 in this case).
It works. Thanks for anserws, especially the hint to dumpbin!