VBoxCheckImports.cpp@ 93115

Last change on this file since 93115 was 93115, checked in by vboxsync, 3 years ago
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1	/* $Id: VBoxCheckImports.cpp 93115 2022-01-01 11:31:46Z vboxsync $ */
2	/** @file
3	* IPRT - Checks that a windows image only imports from a given set of DLLs.
4	*/
5
6	/*
7	* Copyright (C) 2012-2022 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*/
17
18
19	/*********************************************************************************************************************************
20	* Header Files *
21	*********************************************************************************************************************************/
22	#include <iprt/formats/mz.h>
23	#include <iprt/formats/pecoff.h>
24	#include <stdio.h>
25	#include <stdlib.h>
26	#include <string.h>
27
28
29	/*********************************************************************************************************************************
30	* Structures and Typedefs *
31	*********************************************************************************************************************************/
32	typedef struct
33	{
34	const char *pszImage;
35	FILE *pFile;
36	bool f32Bit;
37	union
38	{
39	IMAGE_NT_HEADERS32 Nt32;
40	IMAGE_NT_HEADERS64 Nt64;
41	} Hdrs;
42
43	uint32_t cSections;
44	PIMAGE_SECTION_HEADER paSections;
45	} MYIMAGE;
46
47
48	static bool Failed(MYIMAGE pThis, const char pszFmt, ...)
49	{
50	va_list va;
51	fprintf(stderr, "error '%s': ", pThis->pszImage);
52	va_start(va, pszFmt);
53	vfprintf(stderr, pszFmt, va);
54	va_end(va);
55	fprintf(stderr, "\n");
56	return false;
57	}
58
59
60	static bool ReadPeHeaders(MYIMAGE *pThis)
61	{
62	/*
63	* MZ header.
64	*/
65	IMAGE_DOS_HEADER MzHdr;
66	if (fread(&MzHdr, sizeof(MzHdr), 1, pThis->pFile) != 1)
67	return Failed(pThis, "Reading DOS header");
68
69	if (MzHdr.e_magic != IMAGE_DOS_SIGNATURE)
70	return Failed(pThis, "No MZ magic (found %#x)", MzHdr.e_magic);
71
72	if (fseek(pThis->pFile, MzHdr.e_lfanew, SEEK_SET) != 0)
73	return Failed(pThis, "Seeking to %#lx", (unsigned long)MzHdr.e_lfanew);
74
75	/*
76	* NT signature + file header.
77	*/
78	if (fread(&pThis->Hdrs.Nt32, offsetof(IMAGE_NT_HEADERS32, OptionalHeader), 1, pThis->pFile) != 1)
79	return Failed(pThis, "Reading NT file header");
80
81	if (pThis->Hdrs.Nt32.Signature != IMAGE_NT_SIGNATURE)
82	return Failed(pThis, "No PE magic (found %#x)", pThis->Hdrs.Nt32.Signature);
83
84	if (pThis->Hdrs.Nt32.FileHeader.SizeOfOptionalHeader == sizeof(pThis->Hdrs.Nt32.OptionalHeader))
85	pThis->f32Bit = true;
86	else if (pThis->Hdrs.Nt32.FileHeader.SizeOfOptionalHeader == sizeof(pThis->Hdrs.Nt64.OptionalHeader))
87	pThis->f32Bit = false;
88	else
89	return Failed(pThis, "Unsupported SizeOfOptionalHeaders value: %#x",
90	pThis->Hdrs.Nt32.FileHeader.SizeOfOptionalHeader);
91
92	/*
93	* NT optional header.
94	*/
95	if (fread(&pThis->Hdrs.Nt32.OptionalHeader, pThis->Hdrs.Nt32.FileHeader.SizeOfOptionalHeader, 1, pThis->pFile) != 1)
96	return Failed(pThis, "Reading NT optional header");
97
98	if ( pThis->Hdrs.Nt32.OptionalHeader.Magic
99	!= (pThis->f32Bit ? IMAGE_NT_OPTIONAL_HDR32_MAGIC : IMAGE_NT_OPTIONAL_HDR64_MAGIC) )
100	return Failed(pThis, "Bad optional header magic: %#x", pThis->Hdrs.Nt32.OptionalHeader.Magic);
101
102	uint32_t NumberOfRvaAndSizes = pThis->f32Bit
103	? pThis->Hdrs.Nt32.OptionalHeader.NumberOfRvaAndSizes
104	: pThis->Hdrs.Nt64.OptionalHeader.NumberOfRvaAndSizes;
105	if (NumberOfRvaAndSizes != IMAGE_NUMBEROF_DIRECTORY_ENTRIES)
106	return Failed(pThis, "Unsupported NumberOfRvaAndSizes value: %#x", NumberOfRvaAndSizes);
107
108	/*
109	* Read the section table.
110	*/
111	pThis->cSections = pThis->Hdrs.Nt32.FileHeader.NumberOfSections;
112	if (!pThis->cSections)
113	return Failed(pThis, "No sections in image!");
114	pThis->paSections = (PIMAGE_SECTION_HEADER)calloc(sizeof(pThis->paSections[0]), pThis->cSections);
115	if (!pThis->paSections)
116	return Failed(pThis, "Out of memory!");
117	if (fread(pThis->paSections, sizeof(pThis->paSections[0]), pThis->cSections, pThis->pFile) != pThis->cSections)
118	return Failed(pThis, "Reading NT section headers");
119
120
121	return true;
122	}
123
124
125	static bool ReadAtRva(MYIMAGE pThis, uint32_t uRva, void pvBuf, size_t cbToRead)
126	{
127	unsigned const uRvaOrg = uRva;
128	size_t const cbToReadOrg = cbToRead;
129
130	/*
131	* Header section.
132	*/
133	int iSh = -1;
134	uint32_t uSectRva = 0;
135	uint32_t offSectRaw = 0;
136	uint32_t cbSectRaw = pThis->f32Bit
137	? pThis->Hdrs.Nt32.OptionalHeader.SizeOfHeaders
138	: pThis->Hdrs.Nt64.OptionalHeader.SizeOfHeaders;
139	uint32_t cbSectMax = pThis->paSections[0].VirtualAddress;
140
141	for (;;)
142	{
143	/* Read if we've got a match. */
144	uint32_t off = uRva - uSectRva;
145	if (off < cbSectMax)
146	{
147	uint32_t cbThis = cbSectMax - off;
148	if (cbThis > cbToRead)
149	cbThis = (uint32_t)cbToRead;
150
151	memset(pvBuf, 0, cbThis);
152
153	if (off < cbSectRaw)
154	{
155	if (fseek(pThis->pFile, offSectRaw + off, SEEK_SET) != 0)
156	return Failed(pThis, "Seeking to %#x", offSectRaw + off);
157	if (fread(pvBuf, RT_MIN(cbThis, cbSectRaw - off), 1, pThis->pFile) != 1)
158	return Failed(pThis, "Reading %u bytes at %#x", RT_MIN(cbThis, cbSectRaw - off), offSectRaw + off);
159	}
160
161	cbToRead -= cbThis;
162	if (!cbToRead)
163	return true;
164	uRva += cbThis;
165	pvBuf = (uint8_t *)pvBuf + cbThis;
166	}
167
168	/* next section */
169	iSh++;
170	if ((unsigned)iSh >= pThis->cSections)
171	return Failed(pThis, "RVA %#x LB %u is outside the image", uRvaOrg, cbToReadOrg);
172	uSectRva = pThis->paSections[iSh].VirtualAddress;
173	offSectRaw = pThis->paSections[iSh].PointerToRawData;
174	cbSectRaw = pThis->paSections[iSh].SizeOfRawData;
175	if ((unsigned)iSh + 1 < pThis->cSections)
176	cbSectMax = pThis->paSections[iSh + 1].VirtualAddress - uSectRva;
177	else
178	cbSectMax = pThis->paSections[iSh].Misc.VirtualSize;
179	}
180	}
181
182
183	static bool ReadStringAtRva(MYIMAGE pThis, uint32_t uRva, char pszBuf, size_t cbMax)
184	{
185	uint32_t const uRvaOrg = uRva;
186
187	/*
188	* Try read the whole string at once.
189	*/
190	uint32_t cbImage = pThis->f32Bit
191	? pThis->Hdrs.Nt32.OptionalHeader.SizeOfImage
192	: pThis->Hdrs.Nt64.OptionalHeader.SizeOfImage;
193	uint32_t cbThis = uRva < cbImage ? cbImage - uRva : 1;
194	if (cbThis > cbMax)
195	cbThis = (uint32_t)cbMax;
196	if (!ReadAtRva(pThis, uRva, pszBuf, cbThis))
197	return false;
198	if (memchr(pszBuf, 0, cbThis) != NULL)
199	return true;
200
201	/*
202	* Read more, byte-by-byte.
203	*/
204	for (;;)
205	{
206	cbMax -= cbThis;
207	if (!cbMax)
208	return Failed(pThis, "String to long at %#x", uRvaOrg);
209	pszBuf += cbThis;
210	uRva += cbThis;
211
212	cbThis = 1;
213	if (!ReadAtRva(pThis, uRva, pszBuf, cbThis))
214	return false;
215	if (!*pszBuf)
216	return true;
217	}
218	}
219
220
221	static void ReadAtRvaAlloc(MYIMAGE pThis, uint32_t uRva, size_t cbToRead)
222	{
223	void *pvBuf = malloc(cbToRead);
224	if (pvBuf)
225	{
226	if (ReadAtRva(pThis, uRva, pvBuf, cbToRead))
227	return pvBuf;
228	free(pvBuf);
229	}
230	else
231	Failed(pThis, "Out of memory!");
232	return NULL;
233	}
234
235
236	static bool ParseAndCheckImports(MYIMAGE pThis, const char *papszAllowed, unsigned cAllowed)
237	{
238	/*
239	* Do we have an import directory? If so, read it.
240	*/
241	IMAGE_DATA_DIRECTORY ImpDir = pThis->f32Bit
242	? pThis->Hdrs.Nt32.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT]
243	: pThis->Hdrs.Nt64.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT];
244	if (ImpDir.Size == 0)
245	return true;
246
247	uint32_t cImps = ImpDir.Size / sizeof(IMAGE_IMPORT_DESCRIPTOR);
248	if (cImps * sizeof(IMAGE_IMPORT_DESCRIPTOR) != ImpDir.Size)
249	return Failed(pThis, "Import directory size is not a multiple of IMAGE_IMPORT_DESCRIPTOR: %#x", ImpDir.Size);
250
251	PIMAGE_IMPORT_DESCRIPTOR paImps = (PIMAGE_IMPORT_DESCRIPTOR)ReadAtRvaAlloc(pThis, ImpDir.VirtualAddress, ImpDir.Size);
252	if (!paImps)
253	return false;
254
255	/* There is usually an empty entry at the end. */
256	if ( paImps[cImps - 1].Name == 0
257	\|\| paImps[cImps - 1].FirstThunk == 0)
258	cImps--;
259
260	/*
261	* Do the processing.
262	*/
263	bool fRc = true;
264	for (uint32_t i = 0; i < cImps; i++)
265	{
266	/* Read the import name string. */
267	char szName[128];
268	if (!ReadStringAtRva(pThis, paImps[i].Name, szName, sizeof(szName)))
269	{
270	fRc = false;
271	break;
272	}
273
274	/* Check it against the list of allowed DLLs. */
275	bool fFound = false;
276	unsigned j = cAllowed;
277	while (j-- > 0)
278	if (stricmp(papszAllowed[j], szName) == 0)
279	{
280	fFound = true;
281	break;
282	}
283	if (!fFound)
284	fRc = Failed(pThis, "Illegal import: '%s'", szName);
285	}
286
287	free(paImps);
288	return fRc;
289	}
290
291
292	static int usage(const char *argv0)
293	{
294	printf("usage: %s --image <image> [allowed-dll [..]]\n", argv0);
295	return RTEXITCODE_SUCCESS;
296	}
297
298
299	int main(int argc, char **argv)
300	{
301	/*
302	* Parse arguments.
303	*/
304	const char *pszImage = NULL;
305	const char papszAllowed = (const char )calloc(argc, sizeof(const char *));
306	unsigned cAllowed = 0;
307
308	for (int i = 1; i < argc; i++)
309	{
310	const char *psz = argv[i];
311	if (*psz == '-')
312	{
313	if (!strcmp(psz, "--image") \|\| !strcmp(psz, "-i"))
314	{
315	if (++i >= argc)
316	{
317	fprintf(stderr, "syntax error: File name expected after '%s'.\n", psz);
318	return RTEXITCODE_SYNTAX;
319	}
320	pszImage = argv[i];
321	}
322	else if ( !strcmp(psz, "--help")
323	\|\| !strcmp(psz, "-help")
324	\|\| !strcmp(psz, "-h")
325	\|\| !strcmp(psz, "-?") )
326	return usage(argv[0]);
327	else if ( !strcmp(psz, "--version")
328	\|\| !strcmp(psz, "-V"))
329	{
330	printf("$Revision: 93115 $\n");
331	return RTEXITCODE_SUCCESS;
332	}
333	else
334	{
335	fprintf(stderr, "syntax error: Unknown option '%s'.\n", psz);
336	return RTEXITCODE_SYNTAX;
337	}
338	}
339	else
340	papszAllowed[cAllowed++] = argv[i];
341	}
342
343	if (!pszImage)
344	{
345	fprintf(stderr, "syntax error: No input file specified.\n");
346	return RTEXITCODE_SYNTAX;
347	}
348
349	/*
350	* Open the image and process headers.
351	*/
352	RTEXITCODE rcExit = RTEXITCODE_FAILURE;
353	MYIMAGE MyImage;
354	memset(&MyImage, 0, sizeof(MyImage));
355	MyImage.pszImage = pszImage;
356	MyImage.pFile = fopen(pszImage, "rb");
357	if (MyImage.pFile)
358	{
359	if ( ReadPeHeaders(&MyImage)
360	&& ParseAndCheckImports(&MyImage, papszAllowed, cAllowed))
361	rcExit = RTEXITCODE_SUCCESS;
362
363	fclose(MyImage.pFile);
364	free(MyImage.paSections);
365	}
366	else
367	Failed(&MyImage, "Failed to open image for binary reading.");
368
369	return rcExit;
370	}
371

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source: vbox/trunk/src/bldprogs/VBoxCheckImports.cpp@ 93115

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