VBoxCheckImports.cpp@ 96445

Last change on this file since 96445 was 96407, checked in by vboxsync, 2 years ago
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1	/* $Id: VBoxCheckImports.cpp 96407 2022-08-22 17:43:14Z 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 and/or its affiliates.
8	*
9	* This file is part of VirtualBox base platform packages, as
10	* available from https://www.virtualbox.org.
11	*
12	* This program is free software; you can redistribute it and/or
13	* modify it under the terms of the GNU General Public License
14	* as published by the Free Software Foundation, in version 3 of the
15	* License.
16	*
17	* This program is distributed in the hope that it will be useful, but
18	* WITHOUT ANY WARRANTY; without even the implied warranty of
19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20	* General Public License for more details.
21	*
22	* You should have received a copy of the GNU General Public License
23	* along with this program; if not, see <https://www.gnu.org/licenses>.
24	*
25	* SPDX-License-Identifier: GPL-3.0-only
26	*/
27
28
29	/*********************************************************************************************************************************
30	* Header Files *
31	*********************************************************************************************************************************/
32	#include <iprt/formats/mz.h>
33	#include <iprt/formats/pecoff.h>
34	#include <stdio.h>
35	#include <stdlib.h>
36	#include <string.h>
37
38
39	/*********************************************************************************************************************************
40	* Structures and Typedefs *
41	*********************************************************************************************************************************/
42	typedef struct
43	{
44	const char *pszImage;
45	FILE *pFile;
46	bool f32Bit;
47	union
48	{
49	IMAGE_NT_HEADERS32 Nt32;
50	IMAGE_NT_HEADERS64 Nt64;
51	} Hdrs;
52
53	uint32_t cSections;
54	PIMAGE_SECTION_HEADER paSections;
55	} MYIMAGE;
56
57
58	static bool Failed(MYIMAGE pThis, const char pszFmt, ...)
59	{
60	va_list va;
61	fprintf(stderr, "error '%s': ", pThis->pszImage);
62	va_start(va, pszFmt);
63	vfprintf(stderr, pszFmt, va);
64	va_end(va);
65	fprintf(stderr, "\n");
66	return false;
67	}
68
69
70	static bool ReadPeHeaders(MYIMAGE *pThis)
71	{
72	/*
73	* MZ header.
74	*/
75	IMAGE_DOS_HEADER MzHdr;
76	if (fread(&MzHdr, sizeof(MzHdr), 1, pThis->pFile) != 1)
77	return Failed(pThis, "Reading DOS header");
78
79	if (MzHdr.e_magic != IMAGE_DOS_SIGNATURE)
80	return Failed(pThis, "No MZ magic (found %#x)", MzHdr.e_magic);
81
82	if (fseek(pThis->pFile, MzHdr.e_lfanew, SEEK_SET) != 0)
83	return Failed(pThis, "Seeking to %#lx", (unsigned long)MzHdr.e_lfanew);
84
85	/*
86	* NT signature + file header.
87	*/
88	if (fread(&pThis->Hdrs.Nt32, offsetof(IMAGE_NT_HEADERS32, OptionalHeader), 1, pThis->pFile) != 1)
89	return Failed(pThis, "Reading NT file header");
90
91	if (pThis->Hdrs.Nt32.Signature != IMAGE_NT_SIGNATURE)
92	return Failed(pThis, "No PE magic (found %#x)", pThis->Hdrs.Nt32.Signature);
93
94	if (pThis->Hdrs.Nt32.FileHeader.SizeOfOptionalHeader == sizeof(pThis->Hdrs.Nt32.OptionalHeader))
95	pThis->f32Bit = true;
96	else if (pThis->Hdrs.Nt32.FileHeader.SizeOfOptionalHeader == sizeof(pThis->Hdrs.Nt64.OptionalHeader))
97	pThis->f32Bit = false;
98	else
99	return Failed(pThis, "Unsupported SizeOfOptionalHeaders value: %#x",
100	pThis->Hdrs.Nt32.FileHeader.SizeOfOptionalHeader);
101
102	/*
103	* NT optional header.
104	*/
105	if (fread(&pThis->Hdrs.Nt32.OptionalHeader, pThis->Hdrs.Nt32.FileHeader.SizeOfOptionalHeader, 1, pThis->pFile) != 1)
106	return Failed(pThis, "Reading NT optional header");
107
108	if ( pThis->Hdrs.Nt32.OptionalHeader.Magic
109	!= (pThis->f32Bit ? IMAGE_NT_OPTIONAL_HDR32_MAGIC : IMAGE_NT_OPTIONAL_HDR64_MAGIC) )
110	return Failed(pThis, "Bad optional header magic: %#x", pThis->Hdrs.Nt32.OptionalHeader.Magic);
111
112	uint32_t NumberOfRvaAndSizes = pThis->f32Bit
113	? pThis->Hdrs.Nt32.OptionalHeader.NumberOfRvaAndSizes
114	: pThis->Hdrs.Nt64.OptionalHeader.NumberOfRvaAndSizes;
115	if (NumberOfRvaAndSizes != IMAGE_NUMBEROF_DIRECTORY_ENTRIES)
116	return Failed(pThis, "Unsupported NumberOfRvaAndSizes value: %#x", NumberOfRvaAndSizes);
117
118	/*
119	* Read the section table.
120	*/
121	pThis->cSections = pThis->Hdrs.Nt32.FileHeader.NumberOfSections;
122	if (!pThis->cSections)
123	return Failed(pThis, "No sections in image!");
124	pThis->paSections = (PIMAGE_SECTION_HEADER)calloc(sizeof(pThis->paSections[0]), pThis->cSections);
125	if (!pThis->paSections)
126	return Failed(pThis, "Out of memory!");
127	if (fread(pThis->paSections, sizeof(pThis->paSections[0]), pThis->cSections, pThis->pFile) != pThis->cSections)
128	return Failed(pThis, "Reading NT section headers");
129
130
131	return true;
132	}
133
134
135	static bool ReadAtRva(MYIMAGE pThis, uint32_t uRva, void pvBuf, size_t cbToRead)
136	{
137	unsigned const uRvaOrg = uRva;
138	size_t const cbToReadOrg = cbToRead;
139
140	/*
141	* Header section.
142	*/
143	int iSh = -1;
144	uint32_t uSectRva = 0;
145	uint32_t offSectRaw = 0;
146	uint32_t cbSectRaw = pThis->f32Bit
147	? pThis->Hdrs.Nt32.OptionalHeader.SizeOfHeaders
148	: pThis->Hdrs.Nt64.OptionalHeader.SizeOfHeaders;
149	uint32_t cbSectMax = pThis->paSections[0].VirtualAddress;
150
151	for (;;)
152	{
153	/* Read if we've got a match. */
154	uint32_t off = uRva - uSectRva;
155	if (off < cbSectMax)
156	{
157	uint32_t cbThis = cbSectMax - off;
158	if (cbThis > cbToRead)
159	cbThis = (uint32_t)cbToRead;
160
161	memset(pvBuf, 0, cbThis);
162
163	if (off < cbSectRaw)
164	{
165	if (fseek(pThis->pFile, offSectRaw + off, SEEK_SET) != 0)
166	return Failed(pThis, "Seeking to %#x", offSectRaw + off);
167	if (fread(pvBuf, RT_MIN(cbThis, cbSectRaw - off), 1, pThis->pFile) != 1)
168	return Failed(pThis, "Reading %u bytes at %#x", RT_MIN(cbThis, cbSectRaw - off), offSectRaw + off);
169	}
170
171	cbToRead -= cbThis;
172	if (!cbToRead)
173	return true;
174	uRva += cbThis;
175	pvBuf = (uint8_t *)pvBuf + cbThis;
176	}
177
178	/* next section */
179	iSh++;
180	if ((unsigned)iSh >= pThis->cSections)
181	return Failed(pThis, "RVA %#x LB %u is outside the image", uRvaOrg, cbToReadOrg);
182	uSectRva = pThis->paSections[iSh].VirtualAddress;
183	offSectRaw = pThis->paSections[iSh].PointerToRawData;
184	cbSectRaw = pThis->paSections[iSh].SizeOfRawData;
185	if ((unsigned)iSh + 1 < pThis->cSections)
186	cbSectMax = pThis->paSections[iSh + 1].VirtualAddress - uSectRva;
187	else
188	cbSectMax = pThis->paSections[iSh].Misc.VirtualSize;
189	}
190	}
191
192
193	static bool ReadStringAtRva(MYIMAGE pThis, uint32_t uRva, char pszBuf, size_t cbMax)
194	{
195	uint32_t const uRvaOrg = uRva;
196
197	/*
198	* Try read the whole string at once.
199	*/
200	uint32_t cbImage = pThis->f32Bit
201	? pThis->Hdrs.Nt32.OptionalHeader.SizeOfImage
202	: pThis->Hdrs.Nt64.OptionalHeader.SizeOfImage;
203	uint32_t cbThis = uRva < cbImage ? cbImage - uRva : 1;
204	if (cbThis > cbMax)
205	cbThis = (uint32_t)cbMax;
206	if (!ReadAtRva(pThis, uRva, pszBuf, cbThis))
207	return false;
208	if (memchr(pszBuf, 0, cbThis) != NULL)
209	return true;
210
211	/*
212	* Read more, byte-by-byte.
213	*/
214	for (;;)
215	{
216	cbMax -= cbThis;
217	if (!cbMax)
218	return Failed(pThis, "String to long at %#x", uRvaOrg);
219	pszBuf += cbThis;
220	uRva += cbThis;
221
222	cbThis = 1;
223	if (!ReadAtRva(pThis, uRva, pszBuf, cbThis))
224	return false;
225	if (!*pszBuf)
226	return true;
227	}
228	}
229
230
231	static void ReadAtRvaAlloc(MYIMAGE pThis, uint32_t uRva, size_t cbToRead)
232	{
233	void *pvBuf = malloc(cbToRead);
234	if (pvBuf)
235	{
236	if (ReadAtRva(pThis, uRva, pvBuf, cbToRead))
237	return pvBuf;
238	free(pvBuf);
239	}
240	else
241	Failed(pThis, "Out of memory!");
242	return NULL;
243	}
244
245
246	static bool ParseAndCheckImports(MYIMAGE pThis, const char *papszAllowed, unsigned cAllowed)
247	{
248	/*
249	* Do we have an import directory? If so, read it.
250	*/
251	IMAGE_DATA_DIRECTORY ImpDir = pThis->f32Bit
252	? pThis->Hdrs.Nt32.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT]
253	: pThis->Hdrs.Nt64.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT];
254	if (ImpDir.Size == 0)
255	return true;
256
257	uint32_t cImps = ImpDir.Size / sizeof(IMAGE_IMPORT_DESCRIPTOR);
258	if (cImps * sizeof(IMAGE_IMPORT_DESCRIPTOR) != ImpDir.Size)
259	return Failed(pThis, "Import directory size is not a multiple of IMAGE_IMPORT_DESCRIPTOR: %#x", ImpDir.Size);
260
261	PIMAGE_IMPORT_DESCRIPTOR paImps = (PIMAGE_IMPORT_DESCRIPTOR)ReadAtRvaAlloc(pThis, ImpDir.VirtualAddress, ImpDir.Size);
262	if (!paImps)
263	return false;
264
265	/* There is usually an empty entry at the end. */
266	if ( paImps[cImps - 1].Name == 0
267	\|\| paImps[cImps - 1].FirstThunk == 0)
268	cImps--;
269
270	/*
271	* Do the processing.
272	*/
273	bool fRc = true;
274	for (uint32_t i = 0; i < cImps; i++)
275	{
276	/* Read the import name string. */
277	char szName[128];
278	if (!ReadStringAtRva(pThis, paImps[i].Name, szName, sizeof(szName)))
279	{
280	fRc = false;
281	break;
282	}
283
284	/* Check it against the list of allowed DLLs. */
285	bool fFound = false;
286	unsigned j = cAllowed;
287	while (j-- > 0)
288	if (stricmp(papszAllowed[j], szName) == 0)
289	{
290	fFound = true;
291	break;
292	}
293	if (!fFound)
294	fRc = Failed(pThis, "Illegal import: '%s'", szName);
295	}
296
297	free(paImps);
298	return fRc;
299	}
300
301
302	static int usage(const char *argv0)
303	{
304	printf("usage: %s --image <image> [allowed-dll [..]]\n", argv0);
305	return RTEXITCODE_SUCCESS;
306	}
307
308
309	int main(int argc, char **argv)
310	{
311	/*
312	* Parse arguments.
313	*/
314	const char *pszImage = NULL;
315	const char papszAllowed = (const char )calloc(argc, sizeof(const char *));
316	unsigned cAllowed = 0;
317
318	for (int i = 1; i < argc; i++)
319	{
320	const char *psz = argv[i];
321	if (*psz == '-')
322	{
323	if (!strcmp(psz, "--image") \|\| !strcmp(psz, "-i"))
324	{
325	if (++i >= argc)
326	{
327	fprintf(stderr, "syntax error: File name expected after '%s'.\n", psz);
328	return RTEXITCODE_SYNTAX;
329	}
330	pszImage = argv[i];
331	}
332	else if ( !strcmp(psz, "--help")
333	\|\| !strcmp(psz, "-help")
334	\|\| !strcmp(psz, "-h")
335	\|\| !strcmp(psz, "-?") )
336	return usage(argv[0]);
337	else if ( !strcmp(psz, "--version")
338	\|\| !strcmp(psz, "-V"))
339	{
340	printf("$Revision: 96407 $\n");
341	return RTEXITCODE_SUCCESS;
342	}
343	else
344	{
345	fprintf(stderr, "syntax error: Unknown option '%s'.\n", psz);
346	return RTEXITCODE_SYNTAX;
347	}
348	}
349	else
350	papszAllowed[cAllowed++] = argv[i];
351	}
352
353	if (!pszImage)
354	{
355	fprintf(stderr, "syntax error: No input file specified.\n");
356	return RTEXITCODE_SYNTAX;
357	}
358
359	/*
360	* Open the image and process headers.
361	*/
362	RTEXITCODE rcExit = RTEXITCODE_FAILURE;
363	MYIMAGE MyImage;
364	memset(&MyImage, 0, sizeof(MyImage));
365	MyImage.pszImage = pszImage;
366	MyImage.pFile = fopen(pszImage, "rb");
367	if (MyImage.pFile)
368	{
369	if ( ReadPeHeaders(&MyImage)
370	&& ParseAndCheckImports(&MyImage, papszAllowed, cAllowed))
371	rcExit = RTEXITCODE_SUCCESS;
372
373	fclose(MyImage.pFile);
374	free(MyImage.paSections);
375	}
376	else
377	Failed(&MyImage, "Failed to open image for binary reading.");
378
379	return rcExit;
380	}
381

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source: vbox/trunk/src/bldprogs/VBoxCheckImports.cpp@ 96445

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