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1 | /** @file\r | |
2 | Implement image verification services for secure boot service\r | |
3 | \r | |
4 | Caution: This file requires additional review when modified.\r | |
5 | This library will have external input - PE/COFF image.\r | |
6 | This external input must be validated carefully to avoid security issue like\r | |
7 | buffer overflow, integer overflow.\r | |
8 | \r | |
9 | DxeImageVerificationLibImageRead() function will make sure the PE/COFF image content\r | |
10 | read is within the image buffer.\r | |
11 | \r | |
12 | DxeImageVerificationHandler(), HashPeImageByType(), HashPeImage() function will accept\r | |
13 | untrusted PE/COFF image and validate its data structure within this image buffer before use.\r | |
14 | \r | |
15 | Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>\r | |
16 | (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>\r | |
17 | SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
18 | \r | |
19 | **/\r | |
20 | \r | |
21 | #include "DxeImageVerificationLib.h"\r | |
22 | \r | |
23 | //\r | |
24 | // Caution: This is used by a function which may receive untrusted input.\r | |
25 | // These global variables hold PE/COFF image data, and they should be validated before use.\r | |
26 | //\r | |
27 | EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION mNtHeader;\r | |
28 | UINT32 mPeCoffHeaderOffset;\r | |
29 | EFI_GUID mCertType;\r | |
30 | \r | |
31 | //\r | |
32 | // Information on current PE/COFF image\r | |
33 | //\r | |
34 | UINTN mImageSize;\r | |
35 | UINT8 *mImageBase = NULL;\r | |
36 | UINT8 mImageDigest[MAX_DIGEST_SIZE];\r | |
37 | UINTN mImageDigestSize;\r | |
38 | \r | |
39 | //\r | |
40 | // Notify string for authorization UI.\r | |
41 | //\r | |
42 | CHAR16 mNotifyString1[MAX_NOTIFY_STRING_LEN] = L"Image verification pass but not found in authorized database!";\r | |
43 | CHAR16 mNotifyString2[MAX_NOTIFY_STRING_LEN] = L"Launch this image anyway? (Yes/Defer/No)";\r | |
44 | //\r | |
45 | // Public Exponent of RSA Key.\r | |
46 | //\r | |
47 | CONST UINT8 mRsaE[] = { 0x01, 0x00, 0x01 };\r | |
48 | \r | |
49 | \r | |
50 | //\r | |
51 | // OID ASN.1 Value for Hash Algorithms\r | |
52 | //\r | |
53 | UINT8 mHashOidValue[] = {\r | |
54 | 0x2B, 0x0E, 0x03, 0x02, 0x1A, // OBJ_sha1\r | |
55 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, // OBJ_sha224\r | |
56 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, // OBJ_sha256\r | |
57 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, // OBJ_sha384\r | |
58 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, // OBJ_sha512\r | |
59 | };\r | |
60 | \r | |
61 | HASH_TABLE mHash[] = {\r | |
62 | { L"SHA1", 20, &mHashOidValue[0], 5, Sha1GetContextSize, Sha1Init, Sha1Update, Sha1Final },\r | |
63 | { L"SHA224", 28, &mHashOidValue[5], 9, NULL, NULL, NULL, NULL },\r | |
64 | { L"SHA256", 32, &mHashOidValue[14], 9, Sha256GetContextSize, Sha256Init, Sha256Update, Sha256Final},\r | |
65 | { L"SHA384", 48, &mHashOidValue[23], 9, Sha384GetContextSize, Sha384Init, Sha384Update, Sha384Final},\r | |
66 | { L"SHA512", 64, &mHashOidValue[32], 9, Sha512GetContextSize, Sha512Init, Sha512Update, Sha512Final}\r | |
67 | };\r | |
68 | \r | |
69 | EFI_STRING mHashTypeStr;\r | |
70 | \r | |
71 | /**\r | |
72 | SecureBoot Hook for processing image verification.\r | |
73 | \r | |
74 | @param[in] VariableName Name of Variable to be found.\r | |
75 | @param[in] VendorGuid Variable vendor GUID.\r | |
76 | @param[in] DataSize Size of Data found. If size is less than the\r | |
77 | data, this value contains the required size.\r | |
78 | @param[in] Data Data pointer.\r | |
79 | \r | |
80 | **/\r | |
81 | VOID\r | |
82 | EFIAPI\r | |
83 | SecureBootHook (\r | |
84 | IN CHAR16 *VariableName,\r | |
85 | IN EFI_GUID *VendorGuid,\r | |
86 | IN UINTN DataSize,\r | |
87 | IN VOID *Data\r | |
88 | );\r | |
89 | \r | |
90 | /**\r | |
91 | Reads contents of a PE/COFF image in memory buffer.\r | |
92 | \r | |
93 | Caution: This function may receive untrusted input.\r | |
94 | PE/COFF image is external input, so this function will make sure the PE/COFF image content\r | |
95 | read is within the image buffer.\r | |
96 | \r | |
97 | @param FileHandle Pointer to the file handle to read the PE/COFF image.\r | |
98 | @param FileOffset Offset into the PE/COFF image to begin the read operation.\r | |
99 | @param ReadSize On input, the size in bytes of the requested read operation.\r | |
100 | On output, the number of bytes actually read.\r | |
101 | @param Buffer Output buffer that contains the data read from the PE/COFF image.\r | |
102 | \r | |
103 | @retval EFI_SUCCESS The specified portion of the PE/COFF image was read and the size\r | |
104 | **/\r | |
105 | EFI_STATUS\r | |
106 | EFIAPI\r | |
107 | DxeImageVerificationLibImageRead (\r | |
108 | IN VOID *FileHandle,\r | |
109 | IN UINTN FileOffset,\r | |
110 | IN OUT UINTN *ReadSize,\r | |
111 | OUT VOID *Buffer\r | |
112 | )\r | |
113 | {\r | |
114 | UINTN EndPosition;\r | |
115 | \r | |
116 | if (FileHandle == NULL || ReadSize == NULL || Buffer == NULL) {\r | |
117 | return EFI_INVALID_PARAMETER;\r | |
118 | }\r | |
119 | \r | |
120 | if (MAX_ADDRESS - FileOffset < *ReadSize) {\r | |
121 | return EFI_INVALID_PARAMETER;\r | |
122 | }\r | |
123 | \r | |
124 | EndPosition = FileOffset + *ReadSize;\r | |
125 | if (EndPosition > mImageSize) {\r | |
126 | *ReadSize = (UINT32)(mImageSize - FileOffset);\r | |
127 | }\r | |
128 | \r | |
129 | if (FileOffset >= mImageSize) {\r | |
130 | *ReadSize = 0;\r | |
131 | }\r | |
132 | \r | |
133 | CopyMem (Buffer, (UINT8 *)((UINTN) FileHandle + FileOffset), *ReadSize);\r | |
134 | \r | |
135 | return EFI_SUCCESS;\r | |
136 | }\r | |
137 | \r | |
138 | \r | |
139 | /**\r | |
140 | Get the image type.\r | |
141 | \r | |
142 | @param[in] File This is a pointer to the device path of the file that is\r | |
143 | being dispatched.\r | |
144 | \r | |
145 | @return UINT32 Image Type\r | |
146 | \r | |
147 | **/\r | |
148 | UINT32\r | |
149 | GetImageType (\r | |
150 | IN CONST EFI_DEVICE_PATH_PROTOCOL *File\r | |
151 | )\r | |
152 | {\r | |
153 | EFI_STATUS Status;\r | |
154 | EFI_HANDLE DeviceHandle;\r | |
155 | EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;\r | |
156 | EFI_BLOCK_IO_PROTOCOL *BlockIo;\r | |
157 | \r | |
158 | if (File == NULL) {\r | |
159 | return IMAGE_UNKNOWN;\r | |
160 | }\r | |
161 | \r | |
162 | //\r | |
163 | // First check to see if File is from a Firmware Volume\r | |
164 | //\r | |
165 | DeviceHandle = NULL;\r | |
166 | TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File;\r | |
167 | Status = gBS->LocateDevicePath (\r | |
168 | &gEfiFirmwareVolume2ProtocolGuid,\r | |
169 | &TempDevicePath,\r | |
170 | &DeviceHandle\r | |
171 | );\r | |
172 | if (!EFI_ERROR (Status)) {\r | |
173 | Status = gBS->OpenProtocol (\r | |
174 | DeviceHandle,\r | |
175 | &gEfiFirmwareVolume2ProtocolGuid,\r | |
176 | NULL,\r | |
177 | NULL,\r | |
178 | NULL,\r | |
179 | EFI_OPEN_PROTOCOL_TEST_PROTOCOL\r | |
180 | );\r | |
181 | if (!EFI_ERROR (Status)) {\r | |
182 | return IMAGE_FROM_FV;\r | |
183 | }\r | |
184 | }\r | |
185 | \r | |
186 | //\r | |
187 | // Next check to see if File is from a Block I/O device\r | |
188 | //\r | |
189 | DeviceHandle = NULL;\r | |
190 | TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File;\r | |
191 | Status = gBS->LocateDevicePath (\r | |
192 | &gEfiBlockIoProtocolGuid,\r | |
193 | &TempDevicePath,\r | |
194 | &DeviceHandle\r | |
195 | );\r | |
196 | if (!EFI_ERROR (Status)) {\r | |
197 | BlockIo = NULL;\r | |
198 | Status = gBS->OpenProtocol (\r | |
199 | DeviceHandle,\r | |
200 | &gEfiBlockIoProtocolGuid,\r | |
201 | (VOID **) &BlockIo,\r | |
202 | NULL,\r | |
203 | NULL,\r | |
204 | EFI_OPEN_PROTOCOL_GET_PROTOCOL\r | |
205 | );\r | |
206 | if (!EFI_ERROR (Status) && BlockIo != NULL) {\r | |
207 | if (BlockIo->Media != NULL) {\r | |
208 | if (BlockIo->Media->RemovableMedia) {\r | |
209 | //\r | |
210 | // Block I/O is present and specifies the media is removable\r | |
211 | //\r | |
212 | return IMAGE_FROM_REMOVABLE_MEDIA;\r | |
213 | } else {\r | |
214 | //\r | |
215 | // Block I/O is present and specifies the media is not removable\r | |
216 | //\r | |
217 | return IMAGE_FROM_FIXED_MEDIA;\r | |
218 | }\r | |
219 | }\r | |
220 | }\r | |
221 | }\r | |
222 | \r | |
223 | //\r | |
224 | // File is not in a Firmware Volume or on a Block I/O device, so check to see if\r | |
225 | // the device path supports the Simple File System Protocol.\r | |
226 | //\r | |
227 | DeviceHandle = NULL;\r | |
228 | TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File;\r | |
229 | Status = gBS->LocateDevicePath (\r | |
230 | &gEfiSimpleFileSystemProtocolGuid,\r | |
231 | &TempDevicePath,\r | |
232 | &DeviceHandle\r | |
233 | );\r | |
234 | if (!EFI_ERROR (Status)) {\r | |
235 | //\r | |
236 | // Simple File System is present without Block I/O, so assume media is fixed.\r | |
237 | //\r | |
238 | return IMAGE_FROM_FIXED_MEDIA;\r | |
239 | }\r | |
240 | \r | |
241 | //\r | |
242 | // File is not from an FV, Block I/O or Simple File System, so the only options\r | |
243 | // left are a PCI Option ROM and a Load File Protocol such as a PXE Boot from a NIC.\r | |
244 | //\r | |
245 | TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File;\r | |
246 | while (!IsDevicePathEndType (TempDevicePath)) {\r | |
247 | switch (DevicePathType (TempDevicePath)) {\r | |
248 | \r | |
249 | case MEDIA_DEVICE_PATH:\r | |
250 | if (DevicePathSubType (TempDevicePath) == MEDIA_RELATIVE_OFFSET_RANGE_DP) {\r | |
251 | return IMAGE_FROM_OPTION_ROM;\r | |
252 | }\r | |
253 | break;\r | |
254 | \r | |
255 | case MESSAGING_DEVICE_PATH:\r | |
256 | if (DevicePathSubType(TempDevicePath) == MSG_MAC_ADDR_DP) {\r | |
257 | return IMAGE_FROM_REMOVABLE_MEDIA;\r | |
258 | }\r | |
259 | break;\r | |
260 | \r | |
261 | default:\r | |
262 | break;\r | |
263 | }\r | |
264 | TempDevicePath = NextDevicePathNode (TempDevicePath);\r | |
265 | }\r | |
266 | return IMAGE_UNKNOWN;\r | |
267 | }\r | |
268 | \r | |
269 | /**\r | |
270 | Calculate hash of Pe/Coff image based on the authenticode image hashing in\r | |
271 | PE/COFF Specification 8.0 Appendix A\r | |
272 | \r | |
273 | Caution: This function may receive untrusted input.\r | |
274 | PE/COFF image is external input, so this function will validate its data structure\r | |
275 | within this image buffer before use.\r | |
276 | \r | |
277 | Notes: PE/COFF image has been checked by BasePeCoffLib PeCoffLoaderGetImageInfo() in\r | |
278 | its caller function DxeImageVerificationHandler().\r | |
279 | \r | |
280 | @param[in] HashAlg Hash algorithm type.\r | |
281 | \r | |
282 | @retval TRUE Successfully hash image.\r | |
283 | @retval FALSE Fail in hash image.\r | |
284 | \r | |
285 | **/\r | |
286 | BOOLEAN\r | |
287 | HashPeImage (\r | |
288 | IN UINT32 HashAlg\r | |
289 | )\r | |
290 | {\r | |
291 | BOOLEAN Status;\r | |
292 | EFI_IMAGE_SECTION_HEADER *Section;\r | |
293 | VOID *HashCtx;\r | |
294 | UINTN CtxSize;\r | |
295 | UINT8 *HashBase;\r | |
296 | UINTN HashSize;\r | |
297 | UINTN SumOfBytesHashed;\r | |
298 | EFI_IMAGE_SECTION_HEADER *SectionHeader;\r | |
299 | UINTN Index;\r | |
300 | UINTN Pos;\r | |
301 | UINT32 CertSize;\r | |
302 | UINT32 NumberOfRvaAndSizes;\r | |
303 | \r | |
304 | HashCtx = NULL;\r | |
305 | SectionHeader = NULL;\r | |
306 | Status = FALSE;\r | |
307 | \r | |
308 | if ((HashAlg >= HASHALG_MAX)) {\r | |
309 | return FALSE;\r | |
310 | }\r | |
311 | \r | |
312 | //\r | |
313 | // Initialize context of hash.\r | |
314 | //\r | |
315 | ZeroMem (mImageDigest, MAX_DIGEST_SIZE);\r | |
316 | \r | |
317 | switch (HashAlg) {\r | |
318 | case HASHALG_SHA1:\r | |
319 | mImageDigestSize = SHA1_DIGEST_SIZE;\r | |
320 | mCertType = gEfiCertSha1Guid;\r | |
321 | break;\r | |
322 | \r | |
323 | case HASHALG_SHA256:\r | |
324 | mImageDigestSize = SHA256_DIGEST_SIZE;\r | |
325 | mCertType = gEfiCertSha256Guid;\r | |
326 | break;\r | |
327 | \r | |
328 | case HASHALG_SHA384:\r | |
329 | mImageDigestSize = SHA384_DIGEST_SIZE;\r | |
330 | mCertType = gEfiCertSha384Guid;\r | |
331 | break;\r | |
332 | \r | |
333 | case HASHALG_SHA512:\r | |
334 | mImageDigestSize = SHA512_DIGEST_SIZE;\r | |
335 | mCertType = gEfiCertSha512Guid;\r | |
336 | break;\r | |
337 | \r | |
338 | default:\r | |
339 | return FALSE;\r | |
340 | }\r | |
341 | \r | |
342 | mHashTypeStr = mHash[HashAlg].Name;\r | |
343 | CtxSize = mHash[HashAlg].GetContextSize();\r | |
344 | \r | |
345 | HashCtx = AllocatePool (CtxSize);\r | |
346 | if (HashCtx == NULL) {\r | |
347 | return FALSE;\r | |
348 | }\r | |
349 | \r | |
350 | // 1. Load the image header into memory.\r | |
351 | \r | |
352 | // 2. Initialize a SHA hash context.\r | |
353 | Status = mHash[HashAlg].HashInit(HashCtx);\r | |
354 | \r | |
355 | if (!Status) {\r | |
356 | goto Done;\r | |
357 | }\r | |
358 | \r | |
359 | //\r | |
360 | // Measuring PE/COFF Image Header;\r | |
361 | // But CheckSum field and SECURITY data directory (certificate) are excluded\r | |
362 | //\r | |
363 | \r | |
364 | //\r | |
365 | // 3. Calculate the distance from the base of the image header to the image checksum address.\r | |
366 | // 4. Hash the image header from its base to beginning of the image checksum.\r | |
367 | //\r | |
368 | HashBase = mImageBase;\r | |
369 | if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {\r | |
370 | //\r | |
371 | // Use PE32 offset.\r | |
372 | //\r | |
373 | HashSize = (UINTN) (&mNtHeader.Pe32->OptionalHeader.CheckSum) - (UINTN) HashBase;\r | |
374 | NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes;\r | |
375 | } else if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC) {\r | |
376 | //\r | |
377 | // Use PE32+ offset.\r | |
378 | //\r | |
379 | HashSize = (UINTN) (&mNtHeader.Pe32Plus->OptionalHeader.CheckSum) - (UINTN) HashBase;\r | |
380 | NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;\r | |
381 | } else {\r | |
382 | //\r | |
383 | // Invalid header magic number.\r | |
384 | //\r | |
385 | Status = FALSE;\r | |
386 | goto Done;\r | |
387 | }\r | |
388 | \r | |
389 | Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);\r | |
390 | if (!Status) {\r | |
391 | goto Done;\r | |
392 | }\r | |
393 | \r | |
394 | //\r | |
395 | // 5. Skip over the image checksum (it occupies a single ULONG).\r | |
396 | //\r | |
397 | if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {\r | |
398 | //\r | |
399 | // 6. Since there is no Cert Directory in optional header, hash everything\r | |
400 | // from the end of the checksum to the end of image header.\r | |
401 | //\r | |
402 | if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {\r | |
403 | //\r | |
404 | // Use PE32 offset.\r | |
405 | //\r | |
406 | HashBase = (UINT8 *) &mNtHeader.Pe32->OptionalHeader.CheckSum + sizeof (UINT32);\r | |
407 | HashSize = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders - ((UINTN) HashBase - (UINTN) mImageBase);\r | |
408 | } else {\r | |
409 | //\r | |
410 | // Use PE32+ offset.\r | |
411 | //\r | |
412 | HashBase = (UINT8 *) &mNtHeader.Pe32Plus->OptionalHeader.CheckSum + sizeof (UINT32);\r | |
413 | HashSize = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders - ((UINTN) HashBase - (UINTN) mImageBase);\r | |
414 | }\r | |
415 | \r | |
416 | if (HashSize != 0) {\r | |
417 | Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);\r | |
418 | if (!Status) {\r | |
419 | goto Done;\r | |
420 | }\r | |
421 | }\r | |
422 | } else {\r | |
423 | //\r | |
424 | // 7. Hash everything from the end of the checksum to the start of the Cert Directory.\r | |
425 | //\r | |
426 | if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {\r | |
427 | //\r | |
428 | // Use PE32 offset.\r | |
429 | //\r | |
430 | HashBase = (UINT8 *) &mNtHeader.Pe32->OptionalHeader.CheckSum + sizeof (UINT32);\r | |
431 | HashSize = (UINTN) (&mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - (UINTN) HashBase;\r | |
432 | } else {\r | |
433 | //\r | |
434 | // Use PE32+ offset.\r | |
435 | //\r | |
436 | HashBase = (UINT8 *) &mNtHeader.Pe32Plus->OptionalHeader.CheckSum + sizeof (UINT32);\r | |
437 | HashSize = (UINTN) (&mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - (UINTN) HashBase;\r | |
438 | }\r | |
439 | \r | |
440 | if (HashSize != 0) {\r | |
441 | Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);\r | |
442 | if (!Status) {\r | |
443 | goto Done;\r | |
444 | }\r | |
445 | }\r | |
446 | \r | |
447 | //\r | |
448 | // 8. Skip over the Cert Directory. (It is sizeof(IMAGE_DATA_DIRECTORY) bytes.)\r | |
449 | // 9. Hash everything from the end of the Cert Directory to the end of image header.\r | |
450 | //\r | |
451 | if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {\r | |
452 | //\r | |
453 | // Use PE32 offset\r | |
454 | //\r | |
455 | HashBase = (UINT8 *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1];\r | |
456 | HashSize = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders - ((UINTN) HashBase - (UINTN) mImageBase);\r | |
457 | } else {\r | |
458 | //\r | |
459 | // Use PE32+ offset.\r | |
460 | //\r | |
461 | HashBase = (UINT8 *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1];\r | |
462 | HashSize = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders - ((UINTN) HashBase - (UINTN) mImageBase);\r | |
463 | }\r | |
464 | \r | |
465 | if (HashSize != 0) {\r | |
466 | Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);\r | |
467 | if (!Status) {\r | |
468 | goto Done;\r | |
469 | }\r | |
470 | }\r | |
471 | }\r | |
472 | \r | |
473 | //\r | |
474 | // 10. Set the SUM_OF_BYTES_HASHED to the size of the header.\r | |
475 | //\r | |
476 | if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {\r | |
477 | //\r | |
478 | // Use PE32 offset.\r | |
479 | //\r | |
480 | SumOfBytesHashed = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders;\r | |
481 | } else {\r | |
482 | //\r | |
483 | // Use PE32+ offset\r | |
484 | //\r | |
485 | SumOfBytesHashed = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders;\r | |
486 | }\r | |
487 | \r | |
488 | \r | |
489 | Section = (EFI_IMAGE_SECTION_HEADER *) (\r | |
490 | mImageBase +\r | |
491 | mPeCoffHeaderOffset +\r | |
492 | sizeof (UINT32) +\r | |
493 | sizeof (EFI_IMAGE_FILE_HEADER) +\r | |
494 | mNtHeader.Pe32->FileHeader.SizeOfOptionalHeader\r | |
495 | );\r | |
496 | \r | |
497 | //\r | |
498 | // 11. Build a temporary table of pointers to all the IMAGE_SECTION_HEADER\r | |
499 | // structures in the image. The 'NumberOfSections' field of the image\r | |
500 | // header indicates how big the table should be. Do not include any\r | |
501 | // IMAGE_SECTION_HEADERs in the table whose 'SizeOfRawData' field is zero.\r | |
502 | //\r | |
503 | SectionHeader = (EFI_IMAGE_SECTION_HEADER *) AllocateZeroPool (sizeof (EFI_IMAGE_SECTION_HEADER) * mNtHeader.Pe32->FileHeader.NumberOfSections);\r | |
504 | if (SectionHeader == NULL) {\r | |
505 | Status = FALSE;\r | |
506 | goto Done;\r | |
507 | }\r | |
508 | //\r | |
509 | // 12. Using the 'PointerToRawData' in the referenced section headers as\r | |
510 | // a key, arrange the elements in the table in ascending order. In other\r | |
511 | // words, sort the section headers according to the disk-file offset of\r | |
512 | // the section.\r | |
513 | //\r | |
514 | for (Index = 0; Index < mNtHeader.Pe32->FileHeader.NumberOfSections; Index++) {\r | |
515 | Pos = Index;\r | |
516 | while ((Pos > 0) && (Section->PointerToRawData < SectionHeader[Pos - 1].PointerToRawData)) {\r | |
517 | CopyMem (&SectionHeader[Pos], &SectionHeader[Pos - 1], sizeof (EFI_IMAGE_SECTION_HEADER));\r | |
518 | Pos--;\r | |
519 | }\r | |
520 | CopyMem (&SectionHeader[Pos], Section, sizeof (EFI_IMAGE_SECTION_HEADER));\r | |
521 | Section += 1;\r | |
522 | }\r | |
523 | \r | |
524 | //\r | |
525 | // 13. Walk through the sorted table, bring the corresponding section\r | |
526 | // into memory, and hash the entire section (using the 'SizeOfRawData'\r | |
527 | // field in the section header to determine the amount of data to hash).\r | |
528 | // 14. Add the section's 'SizeOfRawData' to SUM_OF_BYTES_HASHED .\r | |
529 | // 15. Repeat steps 13 and 14 for all the sections in the sorted table.\r | |
530 | //\r | |
531 | for (Index = 0; Index < mNtHeader.Pe32->FileHeader.NumberOfSections; Index++) {\r | |
532 | Section = &SectionHeader[Index];\r | |
533 | if (Section->SizeOfRawData == 0) {\r | |
534 | continue;\r | |
535 | }\r | |
536 | HashBase = mImageBase + Section->PointerToRawData;\r | |
537 | HashSize = (UINTN) Section->SizeOfRawData;\r | |
538 | \r | |
539 | Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);\r | |
540 | if (!Status) {\r | |
541 | goto Done;\r | |
542 | }\r | |
543 | \r | |
544 | SumOfBytesHashed += HashSize;\r | |
545 | }\r | |
546 | \r | |
547 | //\r | |
548 | // 16. If the file size is greater than SUM_OF_BYTES_HASHED, there is extra\r | |
549 | // data in the file that needs to be added to the hash. This data begins\r | |
550 | // at file offset SUM_OF_BYTES_HASHED and its length is:\r | |
551 | // FileSize - (CertDirectory->Size)\r | |
552 | //\r | |
553 | if (mImageSize > SumOfBytesHashed) {\r | |
554 | HashBase = mImageBase + SumOfBytesHashed;\r | |
555 | \r | |
556 | if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {\r | |
557 | CertSize = 0;\r | |
558 | } else {\r | |
559 | if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {\r | |
560 | //\r | |
561 | // Use PE32 offset.\r | |
562 | //\r | |
563 | CertSize = mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size;\r | |
564 | } else {\r | |
565 | //\r | |
566 | // Use PE32+ offset.\r | |
567 | //\r | |
568 | CertSize = mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size;\r | |
569 | }\r | |
570 | }\r | |
571 | \r | |
572 | if (mImageSize > CertSize + SumOfBytesHashed) {\r | |
573 | HashSize = (UINTN) (mImageSize - CertSize - SumOfBytesHashed);\r | |
574 | \r | |
575 | Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);\r | |
576 | if (!Status) {\r | |
577 | goto Done;\r | |
578 | }\r | |
579 | } else if (mImageSize < CertSize + SumOfBytesHashed) {\r | |
580 | Status = FALSE;\r | |
581 | goto Done;\r | |
582 | }\r | |
583 | }\r | |
584 | \r | |
585 | Status = mHash[HashAlg].HashFinal(HashCtx, mImageDigest);\r | |
586 | \r | |
587 | Done:\r | |
588 | if (HashCtx != NULL) {\r | |
589 | FreePool (HashCtx);\r | |
590 | }\r | |
591 | if (SectionHeader != NULL) {\r | |
592 | FreePool (SectionHeader);\r | |
593 | }\r | |
594 | return Status;\r | |
595 | }\r | |
596 | \r | |
597 | /**\r | |
598 | Recognize the Hash algorithm in PE/COFF Authenticode and calculate hash of\r | |
599 | Pe/Coff image based on the authenticode image hashing in PE/COFF Specification\r | |
600 | 8.0 Appendix A\r | |
601 | \r | |
602 | Caution: This function may receive untrusted input.\r | |
603 | PE/COFF image is external input, so this function will validate its data structure\r | |
604 | within this image buffer before use.\r | |
605 | \r | |
606 | @param[in] AuthData Pointer to the Authenticode Signature retrieved from signed image.\r | |
607 | @param[in] AuthDataSize Size of the Authenticode Signature in bytes.\r | |
608 | \r | |
609 | @retval EFI_UNSUPPORTED Hash algorithm is not supported.\r | |
610 | @retval EFI_SUCCESS Hash successfully.\r | |
611 | \r | |
612 | **/\r | |
613 | EFI_STATUS\r | |
614 | HashPeImageByType (\r | |
615 | IN UINT8 *AuthData,\r | |
616 | IN UINTN AuthDataSize\r | |
617 | )\r | |
618 | {\r | |
619 | UINT8 Index;\r | |
620 | \r | |
621 | for (Index = 0; Index < HASHALG_MAX; Index++) {\r | |
622 | //\r | |
623 | // Check the Hash algorithm in PE/COFF Authenticode.\r | |
624 | // According to PKCS#7 Definition:\r | |
625 | // SignedData ::= SEQUENCE {\r | |
626 | // version Version,\r | |
627 | // digestAlgorithms DigestAlgorithmIdentifiers,\r | |
628 | // contentInfo ContentInfo,\r | |
629 | // .... }\r | |
630 | // The DigestAlgorithmIdentifiers can be used to determine the hash algorithm in PE/COFF hashing\r | |
631 | // This field has the fixed offset (+32) in final Authenticode ASN.1 data.\r | |
632 | // Fixed offset (+32) is calculated based on two bytes of length encoding.\r | |
633 | //\r | |
634 | if ((*(AuthData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE) {\r | |
635 | //\r | |
636 | // Only support two bytes of Long Form of Length Encoding.\r | |
637 | //\r | |
638 | continue;\r | |
639 | }\r | |
640 | \r | |
641 | if (AuthDataSize < 32 + mHash[Index].OidLength) {\r | |
642 | return EFI_UNSUPPORTED;\r | |
643 | }\r | |
644 | \r | |
645 | if (CompareMem (AuthData + 32, mHash[Index].OidValue, mHash[Index].OidLength) == 0) {\r | |
646 | break;\r | |
647 | }\r | |
648 | }\r | |
649 | \r | |
650 | if (Index == HASHALG_MAX) {\r | |
651 | return EFI_UNSUPPORTED;\r | |
652 | }\r | |
653 | \r | |
654 | //\r | |
655 | // HASH PE Image based on Hash algorithm in PE/COFF Authenticode.\r | |
656 | //\r | |
657 | if (!HashPeImage(Index)) {\r | |
658 | return EFI_UNSUPPORTED;\r | |
659 | }\r | |
660 | \r | |
661 | return EFI_SUCCESS;\r | |
662 | }\r | |
663 | \r | |
664 | \r | |
665 | /**\r | |
666 | Returns the size of a given image execution info table in bytes.\r | |
667 | \r | |
668 | This function returns the size, in bytes, of the image execution info table specified by\r | |
669 | ImageExeInfoTable. If ImageExeInfoTable is NULL, then 0 is returned.\r | |
670 | \r | |
671 | @param ImageExeInfoTable A pointer to a image execution info table structure.\r | |
672 | \r | |
673 | @retval 0 If ImageExeInfoTable is NULL.\r | |
674 | @retval Others The size of a image execution info table in bytes.\r | |
675 | \r | |
676 | **/\r | |
677 | UINTN\r | |
678 | GetImageExeInfoTableSize (\r | |
679 | EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable\r | |
680 | )\r | |
681 | {\r | |
682 | UINTN Index;\r | |
683 | EFI_IMAGE_EXECUTION_INFO *ImageExeInfoItem;\r | |
684 | UINTN TotalSize;\r | |
685 | \r | |
686 | if (ImageExeInfoTable == NULL) {\r | |
687 | return 0;\r | |
688 | }\r | |
689 | \r | |
690 | ImageExeInfoItem = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) ImageExeInfoTable + sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE));\r | |
691 | TotalSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE);\r | |
692 | for (Index = 0; Index < ImageExeInfoTable->NumberOfImages; Index++) {\r | |
693 | TotalSize += ReadUnaligned32 ((UINT32 *) &ImageExeInfoItem->InfoSize);\r | |
694 | ImageExeInfoItem = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) ImageExeInfoItem + ReadUnaligned32 ((UINT32 *) &ImageExeInfoItem->InfoSize));\r | |
695 | }\r | |
696 | \r | |
697 | return TotalSize;\r | |
698 | }\r | |
699 | \r | |
700 | /**\r | |
701 | Create an Image Execution Information Table entry and add it to system configuration table.\r | |
702 | \r | |
703 | @param[in] Action Describes the action taken by the firmware regarding this image.\r | |
704 | @param[in] Name Input a null-terminated, user-friendly name.\r | |
705 | @param[in] DevicePath Input device path pointer.\r | |
706 | @param[in] Signature Input signature info in EFI_SIGNATURE_LIST data structure.\r | |
707 | @param[in] SignatureSize Size of signature. Must be zero if Signature is NULL.\r | |
708 | \r | |
709 | **/\r | |
710 | VOID\r | |
711 | AddImageExeInfo (\r | |
712 | IN EFI_IMAGE_EXECUTION_ACTION Action,\r | |
713 | IN CHAR16 *Name OPTIONAL,\r | |
714 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,\r | |
715 | IN EFI_SIGNATURE_LIST *Signature OPTIONAL,\r | |
716 | IN UINTN SignatureSize\r | |
717 | )\r | |
718 | {\r | |
719 | EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable;\r | |
720 | EFI_IMAGE_EXECUTION_INFO_TABLE *NewImageExeInfoTable;\r | |
721 | EFI_IMAGE_EXECUTION_INFO *ImageExeInfoEntry;\r | |
722 | UINTN ImageExeInfoTableSize;\r | |
723 | UINTN NewImageExeInfoEntrySize;\r | |
724 | UINTN NameStringLen;\r | |
725 | UINTN DevicePathSize;\r | |
726 | CHAR16 *NameStr;\r | |
727 | \r | |
728 | ImageExeInfoTable = NULL;\r | |
729 | NewImageExeInfoTable = NULL;\r | |
730 | ImageExeInfoEntry = NULL;\r | |
731 | NameStringLen = 0;\r | |
732 | NameStr = NULL;\r | |
733 | \r | |
734 | if (DevicePath == NULL) {\r | |
735 | return ;\r | |
736 | }\r | |
737 | \r | |
738 | if (Name != NULL) {\r | |
739 | NameStringLen = StrSize (Name);\r | |
740 | } else {\r | |
741 | NameStringLen = sizeof (CHAR16);\r | |
742 | }\r | |
743 | \r | |
744 | EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable);\r | |
745 | if (ImageExeInfoTable != NULL) {\r | |
746 | //\r | |
747 | // The table has been found!\r | |
748 | // We must enlarge the table to accommodate the new exe info entry.\r | |
749 | //\r | |
750 | ImageExeInfoTableSize = GetImageExeInfoTableSize (ImageExeInfoTable);\r | |
751 | } else {\r | |
752 | //\r | |
753 | // Not Found!\r | |
754 | // We should create a new table to append to the configuration table.\r | |
755 | //\r | |
756 | ImageExeInfoTableSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE);\r | |
757 | }\r | |
758 | \r | |
759 | DevicePathSize = GetDevicePathSize (DevicePath);\r | |
760 | \r | |
761 | //\r | |
762 | // Signature size can be odd. Pad after signature to ensure next EXECUTION_INFO entry align\r | |
763 | //\r | |
764 | ASSERT (Signature != NULL || SignatureSize == 0);\r | |
765 | NewImageExeInfoEntrySize = sizeof (EFI_IMAGE_EXECUTION_INFO) + NameStringLen + DevicePathSize + SignatureSize;\r | |
766 | \r | |
767 | NewImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize + NewImageExeInfoEntrySize);\r | |
768 | if (NewImageExeInfoTable == NULL) {\r | |
769 | return ;\r | |
770 | }\r | |
771 | \r | |
772 | if (ImageExeInfoTable != NULL) {\r | |
773 | CopyMem (NewImageExeInfoTable, ImageExeInfoTable, ImageExeInfoTableSize);\r | |
774 | } else {\r | |
775 | NewImageExeInfoTable->NumberOfImages = 0;\r | |
776 | }\r | |
777 | NewImageExeInfoTable->NumberOfImages++;\r | |
778 | ImageExeInfoEntry = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) NewImageExeInfoTable + ImageExeInfoTableSize);\r | |
779 | //\r | |
780 | // Update new item's information.\r | |
781 | //\r | |
782 | WriteUnaligned32 ((UINT32 *) ImageExeInfoEntry, Action);\r | |
783 | WriteUnaligned32 ((UINT32 *) ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION)), (UINT32) NewImageExeInfoEntrySize);\r | |
784 | \r | |
785 | NameStr = (CHAR16 *)(ImageExeInfoEntry + 1);\r | |
786 | if (Name != NULL) {\r | |
787 | CopyMem ((UINT8 *) NameStr, Name, NameStringLen);\r | |
788 | } else {\r | |
789 | ZeroMem ((UINT8 *) NameStr, sizeof (CHAR16));\r | |
790 | }\r | |
791 | \r | |
792 | CopyMem (\r | |
793 | (UINT8 *) NameStr + NameStringLen,\r | |
794 | DevicePath,\r | |
795 | DevicePathSize\r | |
796 | );\r | |
797 | if (Signature != NULL) {\r | |
798 | CopyMem (\r | |
799 | (UINT8 *) NameStr + NameStringLen + DevicePathSize,\r | |
800 | Signature,\r | |
801 | SignatureSize\r | |
802 | );\r | |
803 | }\r | |
804 | //\r | |
805 | // Update/replace the image execution table.\r | |
806 | //\r | |
807 | gBS->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID *) NewImageExeInfoTable);\r | |
808 | \r | |
809 | //\r | |
810 | // Free Old table data!\r | |
811 | //\r | |
812 | if (ImageExeInfoTable != NULL) {\r | |
813 | FreePool (ImageExeInfoTable);\r | |
814 | }\r | |
815 | }\r | |
816 | \r | |
817 | /**\r | |
818 | Check whether the hash of an given X.509 certificate is in forbidden database (DBX).\r | |
819 | \r | |
820 | @param[in] Certificate Pointer to X.509 Certificate that is searched for.\r | |
821 | @param[in] CertSize Size of X.509 Certificate.\r | |
822 | @param[in] SignatureList Pointer to the Signature List in forbidden database.\r | |
823 | @param[in] SignatureListSize Size of Signature List.\r | |
824 | @param[out] RevocationTime Return the time that the certificate was revoked.\r | |
825 | \r | |
826 | @return TRUE The certificate hash is found in the forbidden database.\r | |
827 | @return FALSE The certificate hash is not found in the forbidden database.\r | |
828 | \r | |
829 | **/\r | |
830 | BOOLEAN\r | |
831 | IsCertHashFoundInDatabase (\r | |
832 | IN UINT8 *Certificate,\r | |
833 | IN UINTN CertSize,\r | |
834 | IN EFI_SIGNATURE_LIST *SignatureList,\r | |
835 | IN UINTN SignatureListSize,\r | |
836 | OUT EFI_TIME *RevocationTime\r | |
837 | )\r | |
838 | {\r | |
839 | BOOLEAN IsFound;\r | |
840 | BOOLEAN Status;\r | |
841 | EFI_SIGNATURE_LIST *DbxList;\r | |
842 | UINTN DbxSize;\r | |
843 | EFI_SIGNATURE_DATA *CertHash;\r | |
844 | UINTN CertHashCount;\r | |
845 | UINTN Index;\r | |
846 | UINT32 HashAlg;\r | |
847 | VOID *HashCtx;\r | |
848 | UINT8 CertDigest[MAX_DIGEST_SIZE];\r | |
849 | UINT8 *DbxCertHash;\r | |
850 | UINTN SiglistHeaderSize;\r | |
851 | UINT8 *TBSCert;\r | |
852 | UINTN TBSCertSize;\r | |
853 | \r | |
854 | IsFound = FALSE;\r | |
855 | DbxList = SignatureList;\r | |
856 | DbxSize = SignatureListSize;\r | |
857 | HashCtx = NULL;\r | |
858 | HashAlg = HASHALG_MAX;\r | |
859 | \r | |
860 | if ((RevocationTime == NULL) || (DbxList == NULL)) {\r | |
861 | return FALSE;\r | |
862 | }\r | |
863 | \r | |
864 | //\r | |
865 | // Retrieve the TBSCertificate from the X.509 Certificate.\r | |
866 | //\r | |
867 | if (!X509GetTBSCert (Certificate, CertSize, &TBSCert, &TBSCertSize)) {\r | |
868 | return FALSE;\r | |
869 | }\r | |
870 | \r | |
871 | while ((DbxSize > 0) && (SignatureListSize >= DbxList->SignatureListSize)) {\r | |
872 | //\r | |
873 | // Determine Hash Algorithm of Certificate in the forbidden database.\r | |
874 | //\r | |
875 | if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha256Guid)) {\r | |
876 | HashAlg = HASHALG_SHA256;\r | |
877 | } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha384Guid)) {\r | |
878 | HashAlg = HASHALG_SHA384;\r | |
879 | } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha512Guid)) {\r | |
880 | HashAlg = HASHALG_SHA512;\r | |
881 | } else {\r | |
882 | DbxSize -= DbxList->SignatureListSize;\r | |
883 | DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize);\r | |
884 | continue;\r | |
885 | }\r | |
886 | \r | |
887 | //\r | |
888 | // Calculate the hash value of current TBSCertificate for comparision.\r | |
889 | //\r | |
890 | if (mHash[HashAlg].GetContextSize == NULL) {\r | |
891 | goto Done;\r | |
892 | }\r | |
893 | ZeroMem (CertDigest, MAX_DIGEST_SIZE);\r | |
894 | HashCtx = AllocatePool (mHash[HashAlg].GetContextSize ());\r | |
895 | if (HashCtx == NULL) {\r | |
896 | goto Done;\r | |
897 | }\r | |
898 | Status = mHash[HashAlg].HashInit (HashCtx);\r | |
899 | if (!Status) {\r | |
900 | goto Done;\r | |
901 | }\r | |
902 | Status = mHash[HashAlg].HashUpdate (HashCtx, TBSCert, TBSCertSize);\r | |
903 | if (!Status) {\r | |
904 | goto Done;\r | |
905 | }\r | |
906 | Status = mHash[HashAlg].HashFinal (HashCtx, CertDigest);\r | |
907 | if (!Status) {\r | |
908 | goto Done;\r | |
909 | }\r | |
910 | \r | |
911 | FreePool (HashCtx);\r | |
912 | HashCtx = NULL;\r | |
913 | \r | |
914 | SiglistHeaderSize = sizeof (EFI_SIGNATURE_LIST) + DbxList->SignatureHeaderSize;\r | |
915 | CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) DbxList + SiglistHeaderSize);\r | |
916 | CertHashCount = (DbxList->SignatureListSize - SiglistHeaderSize) / DbxList->SignatureSize;\r | |
917 | for (Index = 0; Index < CertHashCount; Index++) {\r | |
918 | //\r | |
919 | // Iterate each Signature Data Node within this CertList for verify.\r | |
920 | //\r | |
921 | DbxCertHash = CertHash->SignatureData;\r | |
922 | if (CompareMem (DbxCertHash, CertDigest, mHash[HashAlg].DigestLength) == 0) {\r | |
923 | //\r | |
924 | // Hash of Certificate is found in forbidden database.\r | |
925 | //\r | |
926 | IsFound = TRUE;\r | |
927 | \r | |
928 | //\r | |
929 | // Return the revocation time.\r | |
930 | //\r | |
931 | CopyMem (RevocationTime, (EFI_TIME *)(DbxCertHash + mHash[HashAlg].DigestLength), sizeof (EFI_TIME));\r | |
932 | goto Done;\r | |
933 | }\r | |
934 | CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertHash + DbxList->SignatureSize);\r | |
935 | }\r | |
936 | \r | |
937 | DbxSize -= DbxList->SignatureListSize;\r | |
938 | DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize);\r | |
939 | }\r | |
940 | \r | |
941 | Done:\r | |
942 | if (HashCtx != NULL) {\r | |
943 | FreePool (HashCtx);\r | |
944 | }\r | |
945 | \r | |
946 | return IsFound;\r | |
947 | }\r | |
948 | \r | |
949 | /**\r | |
950 | Check whether signature is in specified database.\r | |
951 | \r | |
952 | @param[in] VariableName Name of database variable that is searched in.\r | |
953 | @param[in] Signature Pointer to signature that is searched for.\r | |
954 | @param[in] CertType Pointer to hash algorithm.\r | |
955 | @param[in] SignatureSize Size of Signature.\r | |
956 | \r | |
957 | @return TRUE Found the signature in the variable database.\r | |
958 | @return FALSE Not found the signature in the variable database.\r | |
959 | \r | |
960 | **/\r | |
961 | BOOLEAN\r | |
962 | IsSignatureFoundInDatabase (\r | |
963 | IN CHAR16 *VariableName,\r | |
964 | IN UINT8 *Signature,\r | |
965 | IN EFI_GUID *CertType,\r | |
966 | IN UINTN SignatureSize\r | |
967 | )\r | |
968 | {\r | |
969 | EFI_STATUS Status;\r | |
970 | EFI_SIGNATURE_LIST *CertList;\r | |
971 | EFI_SIGNATURE_DATA *Cert;\r | |
972 | UINTN DataSize;\r | |
973 | UINT8 *Data;\r | |
974 | UINTN Index;\r | |
975 | UINTN CertCount;\r | |
976 | BOOLEAN IsFound;\r | |
977 | \r | |
978 | //\r | |
979 | // Read signature database variable.\r | |
980 | //\r | |
981 | IsFound = FALSE;\r | |
982 | Data = NULL;\r | |
983 | DataSize = 0;\r | |
984 | Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);\r | |
985 | if (Status != EFI_BUFFER_TOO_SMALL) {\r | |
986 | return FALSE;\r | |
987 | }\r | |
988 | \r | |
989 | Data = (UINT8 *) AllocateZeroPool (DataSize);\r | |
990 | if (Data == NULL) {\r | |
991 | return FALSE;\r | |
992 | }\r | |
993 | \r | |
994 | Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, Data);\r | |
995 | if (EFI_ERROR (Status)) {\r | |
996 | goto Done;\r | |
997 | }\r | |
998 | //\r | |
999 | // Enumerate all signature data in SigDB to check if signature exists for executable.\r | |
1000 | //\r | |
1001 | CertList = (EFI_SIGNATURE_LIST *) Data;\r | |
1002 | while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {\r | |
1003 | CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;\r | |
1004 | Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);\r | |
1005 | if ((CertList->SignatureSize == sizeof(EFI_SIGNATURE_DATA) - 1 + SignatureSize) && (CompareGuid(&CertList->SignatureType, CertType))) {\r | |
1006 | for (Index = 0; Index < CertCount; Index++) {\r | |
1007 | if (CompareMem (Cert->SignatureData, Signature, SignatureSize) == 0) {\r | |
1008 | //\r | |
1009 | // Find the signature in database.\r | |
1010 | //\r | |
1011 | IsFound = TRUE;\r | |
1012 | //\r | |
1013 | // Entries in UEFI_IMAGE_SECURITY_DATABASE that are used to validate image should be measured\r | |
1014 | //\r | |
1015 | if (StrCmp(VariableName, EFI_IMAGE_SECURITY_DATABASE) == 0) {\r | |
1016 | SecureBootHook (VariableName, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert);\r | |
1017 | }\r | |
1018 | break;\r | |
1019 | }\r | |
1020 | \r | |
1021 | Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);\r | |
1022 | }\r | |
1023 | \r | |
1024 | if (IsFound) {\r | |
1025 | break;\r | |
1026 | }\r | |
1027 | }\r | |
1028 | \r | |
1029 | DataSize -= CertList->SignatureListSize;\r | |
1030 | CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);\r | |
1031 | }\r | |
1032 | \r | |
1033 | Done:\r | |
1034 | if (Data != NULL) {\r | |
1035 | FreePool (Data);\r | |
1036 | }\r | |
1037 | \r | |
1038 | return IsFound;\r | |
1039 | }\r | |
1040 | \r | |
1041 | /**\r | |
1042 | Check whether the timestamp is valid by comparing the signing time and the revocation time.\r | |
1043 | \r | |
1044 | @param SigningTime A pointer to the signing time.\r | |
1045 | @param RevocationTime A pointer to the revocation time.\r | |
1046 | \r | |
1047 | @retval TRUE The SigningTime is not later than the RevocationTime.\r | |
1048 | @retval FALSE The SigningTime is later than the RevocationTime.\r | |
1049 | \r | |
1050 | **/\r | |
1051 | BOOLEAN\r | |
1052 | IsValidSignatureByTimestamp (\r | |
1053 | IN EFI_TIME *SigningTime,\r | |
1054 | IN EFI_TIME *RevocationTime\r | |
1055 | )\r | |
1056 | {\r | |
1057 | if (SigningTime->Year != RevocationTime->Year) {\r | |
1058 | return (BOOLEAN) (SigningTime->Year < RevocationTime->Year);\r | |
1059 | } else if (SigningTime->Month != RevocationTime->Month) {\r | |
1060 | return (BOOLEAN) (SigningTime->Month < RevocationTime->Month);\r | |
1061 | } else if (SigningTime->Day != RevocationTime->Day) {\r | |
1062 | return (BOOLEAN) (SigningTime->Day < RevocationTime->Day);\r | |
1063 | } else if (SigningTime->Hour != RevocationTime->Hour) {\r | |
1064 | return (BOOLEAN) (SigningTime->Hour < RevocationTime->Hour);\r | |
1065 | } else if (SigningTime->Minute != RevocationTime->Minute) {\r | |
1066 | return (BOOLEAN) (SigningTime->Minute < RevocationTime->Minute);\r | |
1067 | }\r | |
1068 | \r | |
1069 | return (BOOLEAN) (SigningTime->Second <= RevocationTime->Second);\r | |
1070 | }\r | |
1071 | \r | |
1072 | /**\r | |
1073 | Check if the given time value is zero.\r | |
1074 | \r | |
1075 | @param[in] Time Pointer of a time value.\r | |
1076 | \r | |
1077 | @retval TRUE The Time is Zero.\r | |
1078 | @retval FALSE The Time is not Zero.\r | |
1079 | \r | |
1080 | **/\r | |
1081 | BOOLEAN\r | |
1082 | IsTimeZero (\r | |
1083 | IN EFI_TIME *Time\r | |
1084 | )\r | |
1085 | {\r | |
1086 | if ((Time->Year == 0) && (Time->Month == 0) && (Time->Day == 0) &&\r | |
1087 | (Time->Hour == 0) && (Time->Minute == 0) && (Time->Second == 0)) {\r | |
1088 | return TRUE;\r | |
1089 | }\r | |
1090 | \r | |
1091 | return FALSE;\r | |
1092 | }\r | |
1093 | \r | |
1094 | /**\r | |
1095 | Check whether the timestamp signature is valid and the signing time is also earlier than\r | |
1096 | the revocation time.\r | |
1097 | \r | |
1098 | @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.\r | |
1099 | @param[in] AuthDataSize Size of the Authenticode signature in bytes.\r | |
1100 | @param[in] RevocationTime The time that the certificate was revoked.\r | |
1101 | \r | |
1102 | @retval TRUE Timestamp signature is valid and signing time is no later than the\r | |
1103 | revocation time.\r | |
1104 | @retval FALSE Timestamp signature is not valid or the signing time is later than the\r | |
1105 | revocation time.\r | |
1106 | \r | |
1107 | **/\r | |
1108 | BOOLEAN\r | |
1109 | PassTimestampCheck (\r | |
1110 | IN UINT8 *AuthData,\r | |
1111 | IN UINTN AuthDataSize,\r | |
1112 | IN EFI_TIME *RevocationTime\r | |
1113 | )\r | |
1114 | {\r | |
1115 | EFI_STATUS Status;\r | |
1116 | BOOLEAN VerifyStatus;\r | |
1117 | EFI_SIGNATURE_LIST *CertList;\r | |
1118 | EFI_SIGNATURE_DATA *Cert;\r | |
1119 | UINT8 *DbtData;\r | |
1120 | UINTN DbtDataSize;\r | |
1121 | UINT8 *RootCert;\r | |
1122 | UINTN RootCertSize;\r | |
1123 | UINTN Index;\r | |
1124 | UINTN CertCount;\r | |
1125 | EFI_TIME SigningTime;\r | |
1126 | \r | |
1127 | //\r | |
1128 | // Variable Initialization\r | |
1129 | //\r | |
1130 | VerifyStatus = FALSE;\r | |
1131 | DbtData = NULL;\r | |
1132 | CertList = NULL;\r | |
1133 | Cert = NULL;\r | |
1134 | RootCert = NULL;\r | |
1135 | RootCertSize = 0;\r | |
1136 | \r | |
1137 | //\r | |
1138 | // If RevocationTime is zero, the certificate shall be considered to always be revoked.\r | |
1139 | //\r | |
1140 | if (IsTimeZero (RevocationTime)) {\r | |
1141 | return FALSE;\r | |
1142 | }\r | |
1143 | \r | |
1144 | //\r | |
1145 | // RevocationTime is non-zero, the certificate should be considered to be revoked from that time and onwards.\r | |
1146 | // Using the dbt to get the trusted TSA certificates.\r | |
1147 | //\r | |
1148 | DbtDataSize = 0;\r | |
1149 | Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, NULL);\r | |
1150 | if (Status != EFI_BUFFER_TOO_SMALL) {\r | |
1151 | goto Done;\r | |
1152 | }\r | |
1153 | DbtData = (UINT8 *) AllocateZeroPool (DbtDataSize);\r | |
1154 | if (DbtData == NULL) {\r | |
1155 | goto Done;\r | |
1156 | }\r | |
1157 | Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, (VOID *) DbtData);\r | |
1158 | if (EFI_ERROR (Status)) {\r | |
1159 | goto Done;\r | |
1160 | }\r | |
1161 | \r | |
1162 | CertList = (EFI_SIGNATURE_LIST *) DbtData;\r | |
1163 | while ((DbtDataSize > 0) && (DbtDataSize >= CertList->SignatureListSize)) {\r | |
1164 | if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {\r | |
1165 | Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);\r | |
1166 | CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;\r | |
1167 | for (Index = 0; Index < CertCount; Index++) {\r | |
1168 | //\r | |
1169 | // Iterate each Signature Data Node within this CertList for verify.\r | |
1170 | //\r | |
1171 | RootCert = Cert->SignatureData;\r | |
1172 | RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);\r | |
1173 | //\r | |
1174 | // Get the signing time if the timestamp signature is valid.\r | |
1175 | //\r | |
1176 | if (ImageTimestampVerify (AuthData, AuthDataSize, RootCert, RootCertSize, &SigningTime)) {\r | |
1177 | //\r | |
1178 | // The signer signature is valid only when the signing time is earlier than revocation time.\r | |
1179 | //\r | |
1180 | if (IsValidSignatureByTimestamp (&SigningTime, RevocationTime)) {\r | |
1181 | VerifyStatus = TRUE;\r | |
1182 | goto Done;\r | |
1183 | }\r | |
1184 | }\r | |
1185 | Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);\r | |
1186 | }\r | |
1187 | }\r | |
1188 | DbtDataSize -= CertList->SignatureListSize;\r | |
1189 | CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);\r | |
1190 | }\r | |
1191 | \r | |
1192 | Done:\r | |
1193 | if (DbtData != NULL) {\r | |
1194 | FreePool (DbtData);\r | |
1195 | }\r | |
1196 | \r | |
1197 | return VerifyStatus;\r | |
1198 | }\r | |
1199 | \r | |
1200 | /**\r | |
1201 | Check whether the image signature is forbidden by the forbidden database (dbx).\r | |
1202 | The image is forbidden to load if any certificates for signing are revoked before signing time.\r | |
1203 | \r | |
1204 | @param[in] AuthData Pointer to the Authenticode signature retrieved from the signed image.\r | |
1205 | @param[in] AuthDataSize Size of the Authenticode signature in bytes.\r | |
1206 | \r | |
1207 | @retval TRUE Image is forbidden by dbx.\r | |
1208 | @retval FALSE Image is not forbidden by dbx.\r | |
1209 | \r | |
1210 | **/\r | |
1211 | BOOLEAN\r | |
1212 | IsForbiddenByDbx (\r | |
1213 | IN UINT8 *AuthData,\r | |
1214 | IN UINTN AuthDataSize\r | |
1215 | )\r | |
1216 | {\r | |
1217 | EFI_STATUS Status;\r | |
1218 | BOOLEAN IsForbidden;\r | |
1219 | UINT8 *Data;\r | |
1220 | UINTN DataSize;\r | |
1221 | EFI_SIGNATURE_LIST *CertList;\r | |
1222 | UINTN CertListSize;\r | |
1223 | EFI_SIGNATURE_DATA *CertData;\r | |
1224 | UINT8 *RootCert;\r | |
1225 | UINTN RootCertSize;\r | |
1226 | UINTN CertCount;\r | |
1227 | UINTN Index;\r | |
1228 | UINT8 *CertBuffer;\r | |
1229 | UINTN BufferLength;\r | |
1230 | UINT8 *TrustedCert;\r | |
1231 | UINTN TrustedCertLength;\r | |
1232 | UINT8 CertNumber;\r | |
1233 | UINT8 *CertPtr;\r | |
1234 | UINT8 *Cert;\r | |
1235 | UINTN CertSize;\r | |
1236 | EFI_TIME RevocationTime;\r | |
1237 | //\r | |
1238 | // Variable Initialization\r | |
1239 | //\r | |
1240 | IsForbidden = FALSE;\r | |
1241 | Data = NULL;\r | |
1242 | CertList = NULL;\r | |
1243 | CertData = NULL;\r | |
1244 | RootCert = NULL;\r | |
1245 | RootCertSize = 0;\r | |
1246 | Cert = NULL;\r | |
1247 | CertBuffer = NULL;\r | |
1248 | BufferLength = 0;\r | |
1249 | TrustedCert = NULL;\r | |
1250 | TrustedCertLength = 0;\r | |
1251 | \r | |
1252 | //\r | |
1253 | // The image will not be forbidden if dbx can't be got.\r | |
1254 | //\r | |
1255 | DataSize = 0;\r | |
1256 | Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);\r | |
1257 | if (Status != EFI_BUFFER_TOO_SMALL) {\r | |
1258 | return IsForbidden;\r | |
1259 | }\r | |
1260 | Data = (UINT8 *) AllocateZeroPool (DataSize);\r | |
1261 | if (Data == NULL) {\r | |
1262 | return IsForbidden;\r | |
1263 | }\r | |
1264 | \r | |
1265 | Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data);\r | |
1266 | if (EFI_ERROR (Status)) {\r | |
1267 | return IsForbidden;\r | |
1268 | }\r | |
1269 | \r | |
1270 | //\r | |
1271 | // Verify image signature with RAW X509 certificates in DBX database.\r | |
1272 | // If passed, the image will be forbidden.\r | |
1273 | //\r | |
1274 | CertList = (EFI_SIGNATURE_LIST *) Data;\r | |
1275 | CertListSize = DataSize;\r | |
1276 | while ((CertListSize > 0) && (CertListSize >= CertList->SignatureListSize)) {\r | |
1277 | if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {\r | |
1278 | CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);\r | |
1279 | CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;\r | |
1280 | \r | |
1281 | for (Index = 0; Index < CertCount; Index++) {\r | |
1282 | //\r | |
1283 | // Iterate each Signature Data Node within this CertList for verify.\r | |
1284 | //\r | |
1285 | RootCert = CertData->SignatureData;\r | |
1286 | RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);\r | |
1287 | \r | |
1288 | //\r | |
1289 | // Call AuthenticodeVerify library to Verify Authenticode struct.\r | |
1290 | //\r | |
1291 | IsForbidden = AuthenticodeVerify (\r | |
1292 | AuthData,\r | |
1293 | AuthDataSize,\r | |
1294 | RootCert,\r | |
1295 | RootCertSize,\r | |
1296 | mImageDigest,\r | |
1297 | mImageDigestSize\r | |
1298 | );\r | |
1299 | if (IsForbidden) {\r | |
1300 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed but signature is forbidden by DBX.\n"));\r | |
1301 | goto Done;\r | |
1302 | }\r | |
1303 | \r | |
1304 | CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData + CertList->SignatureSize);\r | |
1305 | }\r | |
1306 | }\r | |
1307 | \r | |
1308 | CertListSize -= CertList->SignatureListSize;\r | |
1309 | CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);\r | |
1310 | }\r | |
1311 | \r | |
1312 | //\r | |
1313 | // Check X.509 Certificate Hash & Possible Timestamp.\r | |
1314 | //\r | |
1315 | \r | |
1316 | //\r | |
1317 | // Retrieve the certificate stack from AuthData\r | |
1318 | // The output CertStack format will be:\r | |
1319 | // UINT8 CertNumber;\r | |
1320 | // UINT32 Cert1Length;\r | |
1321 | // UINT8 Cert1[];\r | |
1322 | // UINT32 Cert2Length;\r | |
1323 | // UINT8 Cert2[];\r | |
1324 | // ...\r | |
1325 | // UINT32 CertnLength;\r | |
1326 | // UINT8 Certn[];\r | |
1327 | //\r | |
1328 | Pkcs7GetSigners (AuthData, AuthDataSize, &CertBuffer, &BufferLength, &TrustedCert, &TrustedCertLength);\r | |
1329 | if ((BufferLength == 0) || (CertBuffer == NULL) || (*CertBuffer) == 0) {\r | |
1330 | IsForbidden = TRUE;\r | |
1331 | goto Done;\r | |
1332 | }\r | |
1333 | \r | |
1334 | //\r | |
1335 | // Check if any hash of certificates embedded in AuthData is in the forbidden database.\r | |
1336 | //\r | |
1337 | CertNumber = (UINT8) (*CertBuffer);\r | |
1338 | CertPtr = CertBuffer + 1;\r | |
1339 | for (Index = 0; Index < CertNumber; Index++) {\r | |
1340 | CertSize = (UINTN) ReadUnaligned32 ((UINT32 *)CertPtr);\r | |
1341 | Cert = (UINT8 *)CertPtr + sizeof (UINT32);\r | |
1342 | //\r | |
1343 | // Advance CertPtr to the next cert in image signer's cert list\r | |
1344 | //\r | |
1345 | CertPtr = CertPtr + sizeof (UINT32) + CertSize;\r | |
1346 | \r | |
1347 | if (IsCertHashFoundInDatabase (Cert, CertSize, (EFI_SIGNATURE_LIST *)Data, DataSize, &RevocationTime)) {\r | |
1348 | //\r | |
1349 | // Check the timestamp signature and signing time to determine if the image can be trusted.\r | |
1350 | //\r | |
1351 | IsForbidden = TRUE;\r | |
1352 | if (PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime)) {\r | |
1353 | IsForbidden = FALSE;\r | |
1354 | //\r | |
1355 | // Pass DBT check. Continue to check other certs in image signer's cert list against DBX, DBT\r | |
1356 | //\r | |
1357 | continue;\r | |
1358 | }\r | |
1359 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed but signature failed the timestamp check.\n"));\r | |
1360 | goto Done;\r | |
1361 | }\r | |
1362 | \r | |
1363 | }\r | |
1364 | \r | |
1365 | Done:\r | |
1366 | if (Data != NULL) {\r | |
1367 | FreePool (Data);\r | |
1368 | }\r | |
1369 | \r | |
1370 | Pkcs7FreeSigners (CertBuffer);\r | |
1371 | Pkcs7FreeSigners (TrustedCert);\r | |
1372 | \r | |
1373 | return IsForbidden;\r | |
1374 | }\r | |
1375 | \r | |
1376 | \r | |
1377 | /**\r | |
1378 | Check whether the image signature can be verified by the trusted certificates in DB database.\r | |
1379 | \r | |
1380 | @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.\r | |
1381 | @param[in] AuthDataSize Size of the Authenticode signature in bytes.\r | |
1382 | \r | |
1383 | @retval TRUE Image passed verification using certificate in db.\r | |
1384 | @retval FALSE Image didn't pass verification using certificate in db.\r | |
1385 | \r | |
1386 | **/\r | |
1387 | BOOLEAN\r | |
1388 | IsAllowedByDb (\r | |
1389 | IN UINT8 *AuthData,\r | |
1390 | IN UINTN AuthDataSize\r | |
1391 | )\r | |
1392 | {\r | |
1393 | EFI_STATUS Status;\r | |
1394 | BOOLEAN VerifyStatus;\r | |
1395 | EFI_SIGNATURE_LIST *CertList;\r | |
1396 | EFI_SIGNATURE_DATA *CertData;\r | |
1397 | UINTN DataSize;\r | |
1398 | UINT8 *Data;\r | |
1399 | UINT8 *RootCert;\r | |
1400 | UINTN RootCertSize;\r | |
1401 | UINTN Index;\r | |
1402 | UINTN CertCount;\r | |
1403 | UINTN DbxDataSize;\r | |
1404 | UINT8 *DbxData;\r | |
1405 | EFI_TIME RevocationTime;\r | |
1406 | \r | |
1407 | Data = NULL;\r | |
1408 | CertList = NULL;\r | |
1409 | CertData = NULL;\r | |
1410 | RootCert = NULL;\r | |
1411 | DbxData = NULL;\r | |
1412 | RootCertSize = 0;\r | |
1413 | VerifyStatus = FALSE;\r | |
1414 | \r | |
1415 | DataSize = 0;\r | |
1416 | Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);\r | |
1417 | if (Status == EFI_BUFFER_TOO_SMALL) {\r | |
1418 | Data = (UINT8 *) AllocateZeroPool (DataSize);\r | |
1419 | if (Data == NULL) {\r | |
1420 | return VerifyStatus;\r | |
1421 | }\r | |
1422 | \r | |
1423 | Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data);\r | |
1424 | if (EFI_ERROR (Status)) {\r | |
1425 | goto Done;\r | |
1426 | }\r | |
1427 | \r | |
1428 | //\r | |
1429 | // Find X509 certificate in Signature List to verify the signature in pkcs7 signed data.\r | |
1430 | //\r | |
1431 | CertList = (EFI_SIGNATURE_LIST *) Data;\r | |
1432 | while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {\r | |
1433 | if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {\r | |
1434 | CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);\r | |
1435 | CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;\r | |
1436 | \r | |
1437 | for (Index = 0; Index < CertCount; Index++) {\r | |
1438 | //\r | |
1439 | // Iterate each Signature Data Node within this CertList for verify.\r | |
1440 | //\r | |
1441 | RootCert = CertData->SignatureData;\r | |
1442 | RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);\r | |
1443 | \r | |
1444 | //\r | |
1445 | // Call AuthenticodeVerify library to Verify Authenticode struct.\r | |
1446 | //\r | |
1447 | VerifyStatus = AuthenticodeVerify (\r | |
1448 | AuthData,\r | |
1449 | AuthDataSize,\r | |
1450 | RootCert,\r | |
1451 | RootCertSize,\r | |
1452 | mImageDigest,\r | |
1453 | mImageDigestSize\r | |
1454 | );\r | |
1455 | if (VerifyStatus) {\r | |
1456 | //\r | |
1457 | // Here We still need to check if this RootCert's Hash is revoked\r | |
1458 | //\r | |
1459 | DbxDataSize = 0;\r | |
1460 | Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DbxDataSize, NULL);\r | |
1461 | if (Status != EFI_BUFFER_TOO_SMALL) {\r | |
1462 | if (Status != EFI_NOT_FOUND) {\r | |
1463 | VerifyStatus = FALSE;\r | |
1464 | }\r | |
1465 | goto Done;\r | |
1466 | }\r | |
1467 | DbxData = (UINT8 *) AllocateZeroPool (DbxDataSize);\r | |
1468 | if (DbxData == NULL) {\r | |
1469 | //\r | |
1470 | // Force not-allowed-by-db to avoid bypass\r | |
1471 | //\r | |
1472 | VerifyStatus = FALSE;\r | |
1473 | goto Done;\r | |
1474 | }\r | |
1475 | \r | |
1476 | Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DbxDataSize, (VOID *) DbxData);\r | |
1477 | if (EFI_ERROR (Status)) {\r | |
1478 | //\r | |
1479 | // Force not-allowed-by-db to avoid bypass\r | |
1480 | //\r | |
1481 | VerifyStatus = FALSE;\r | |
1482 | goto Done;\r | |
1483 | }\r | |
1484 | \r | |
1485 | if (IsCertHashFoundInDatabase (RootCert, RootCertSize, (EFI_SIGNATURE_LIST *)DbxData, DbxDataSize, &RevocationTime)) {\r | |
1486 | //\r | |
1487 | // Check the timestamp signature and signing time to determine if the RootCert can be trusted.\r | |
1488 | //\r | |
1489 | VerifyStatus = PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime);\r | |
1490 | if (!VerifyStatus) {\r | |
1491 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed and signature is accepted by DB, but its root cert failed the timestamp check.\n"));\r | |
1492 | }\r | |
1493 | }\r | |
1494 | \r | |
1495 | goto Done;\r | |
1496 | }\r | |
1497 | \r | |
1498 | CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData + CertList->SignatureSize);\r | |
1499 | }\r | |
1500 | }\r | |
1501 | \r | |
1502 | DataSize -= CertList->SignatureListSize;\r | |
1503 | CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);\r | |
1504 | }\r | |
1505 | }\r | |
1506 | \r | |
1507 | Done:\r | |
1508 | \r | |
1509 | if (VerifyStatus) {\r | |
1510 | SecureBootHook (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, CertData);\r | |
1511 | }\r | |
1512 | \r | |
1513 | if (Data != NULL) {\r | |
1514 | FreePool (Data);\r | |
1515 | }\r | |
1516 | if (DbxData != NULL) {\r | |
1517 | FreePool (DbxData);\r | |
1518 | }\r | |
1519 | \r | |
1520 | return VerifyStatus;\r | |
1521 | }\r | |
1522 | \r | |
1523 | /**\r | |
1524 | Provide verification service for signed images, which include both signature validation\r | |
1525 | and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and\r | |
1526 | MSFT Authenticode type signatures are supported.\r | |
1527 | \r | |
1528 | In this implementation, only verify external executables when in USER MODE.\r | |
1529 | Executables from FV is bypass, so pass in AuthenticationStatus is ignored.\r | |
1530 | \r | |
1531 | The image verification policy is:\r | |
1532 | If the image is signed,\r | |
1533 | At least one valid signature or at least one hash value of the image must match a record\r | |
1534 | in the security database "db", and no valid signature nor any hash value of the image may\r | |
1535 | be reflected in the security database "dbx".\r | |
1536 | Otherwise, the image is not signed,\r | |
1537 | The SHA256 hash value of the image must match a record in the security database "db", and\r | |
1538 | not be reflected in the security data base "dbx".\r | |
1539 | \r | |
1540 | Caution: This function may receive untrusted input.\r | |
1541 | PE/COFF image is external input, so this function will validate its data structure\r | |
1542 | within this image buffer before use.\r | |
1543 | \r | |
1544 | @param[in] AuthenticationStatus\r | |
1545 | This is the authentication status returned from the security\r | |
1546 | measurement services for the input file.\r | |
1547 | @param[in] File This is a pointer to the device path of the file that is\r | |
1548 | being dispatched. This will optionally be used for logging.\r | |
1549 | @param[in] FileBuffer File buffer matches the input file device path.\r | |
1550 | @param[in] FileSize Size of File buffer matches the input file device path.\r | |
1551 | @param[in] BootPolicy A boot policy that was used to call LoadImage() UEFI service.\r | |
1552 | \r | |
1553 | @retval EFI_SUCCESS The file specified by DevicePath and non-NULL\r | |
1554 | FileBuffer did authenticate, and the platform policy dictates\r | |
1555 | that the DXE Foundation may use the file.\r | |
1556 | @retval EFI_SUCCESS The device path specified by NULL device path DevicePath\r | |
1557 | and non-NULL FileBuffer did authenticate, and the platform\r | |
1558 | policy dictates that the DXE Foundation may execute the image in\r | |
1559 | FileBuffer.\r | |
1560 | @retval EFI_SECURITY_VIOLATION The file specified by File did not authenticate, and\r | |
1561 | the platform policy dictates that File should be placed\r | |
1562 | in the untrusted state. The image has been added to the file\r | |
1563 | execution table.\r | |
1564 | @retval EFI_ACCESS_DENIED The file specified by File and FileBuffer did not\r | |
1565 | authenticate, and the platform policy dictates that the DXE\r | |
1566 | Foundation may not use File. The image has\r | |
1567 | been added to the file execution table.\r | |
1568 | \r | |
1569 | **/\r | |
1570 | EFI_STATUS\r | |
1571 | EFIAPI\r | |
1572 | DxeImageVerificationHandler (\r | |
1573 | IN UINT32 AuthenticationStatus,\r | |
1574 | IN CONST EFI_DEVICE_PATH_PROTOCOL *File,\r | |
1575 | IN VOID *FileBuffer,\r | |
1576 | IN UINTN FileSize,\r | |
1577 | IN BOOLEAN BootPolicy\r | |
1578 | )\r | |
1579 | {\r | |
1580 | EFI_IMAGE_DOS_HEADER *DosHdr;\r | |
1581 | BOOLEAN IsVerified;\r | |
1582 | EFI_SIGNATURE_LIST *SignatureList;\r | |
1583 | UINTN SignatureListSize;\r | |
1584 | EFI_SIGNATURE_DATA *Signature;\r | |
1585 | EFI_IMAGE_EXECUTION_ACTION Action;\r | |
1586 | WIN_CERTIFICATE *WinCertificate;\r | |
1587 | UINT32 Policy;\r | |
1588 | UINT8 *SecureBoot;\r | |
1589 | PE_COFF_LOADER_IMAGE_CONTEXT ImageContext;\r | |
1590 | UINT32 NumberOfRvaAndSizes;\r | |
1591 | WIN_CERTIFICATE_EFI_PKCS *PkcsCertData;\r | |
1592 | WIN_CERTIFICATE_UEFI_GUID *WinCertUefiGuid;\r | |
1593 | UINT8 *AuthData;\r | |
1594 | UINTN AuthDataSize;\r | |
1595 | EFI_IMAGE_DATA_DIRECTORY *SecDataDir;\r | |
1596 | UINT32 OffSet;\r | |
1597 | CHAR16 *NameStr;\r | |
1598 | RETURN_STATUS PeCoffStatus;\r | |
1599 | EFI_STATUS HashStatus;\r | |
1600 | \r | |
1601 | SignatureList = NULL;\r | |
1602 | SignatureListSize = 0;\r | |
1603 | WinCertificate = NULL;\r | |
1604 | SecDataDir = NULL;\r | |
1605 | PkcsCertData = NULL;\r | |
1606 | Action = EFI_IMAGE_EXECUTION_AUTH_UNTESTED;\r | |
1607 | IsVerified = FALSE;\r | |
1608 | \r | |
1609 | \r | |
1610 | //\r | |
1611 | // Check the image type and get policy setting.\r | |
1612 | //\r | |
1613 | switch (GetImageType (File)) {\r | |
1614 | \r | |
1615 | case IMAGE_FROM_FV:\r | |
1616 | Policy = ALWAYS_EXECUTE;\r | |
1617 | break;\r | |
1618 | \r | |
1619 | case IMAGE_FROM_OPTION_ROM:\r | |
1620 | Policy = PcdGet32 (PcdOptionRomImageVerificationPolicy);\r | |
1621 | break;\r | |
1622 | \r | |
1623 | case IMAGE_FROM_REMOVABLE_MEDIA:\r | |
1624 | Policy = PcdGet32 (PcdRemovableMediaImageVerificationPolicy);\r | |
1625 | break;\r | |
1626 | \r | |
1627 | case IMAGE_FROM_FIXED_MEDIA:\r | |
1628 | Policy = PcdGet32 (PcdFixedMediaImageVerificationPolicy);\r | |
1629 | break;\r | |
1630 | \r | |
1631 | default:\r | |
1632 | Policy = DENY_EXECUTE_ON_SECURITY_VIOLATION;\r | |
1633 | break;\r | |
1634 | }\r | |
1635 | //\r | |
1636 | // If policy is always/never execute, return directly.\r | |
1637 | //\r | |
1638 | if (Policy == ALWAYS_EXECUTE) {\r | |
1639 | return EFI_SUCCESS;\r | |
1640 | }\r | |
1641 | if (Policy == NEVER_EXECUTE) {\r | |
1642 | return EFI_ACCESS_DENIED;\r | |
1643 | }\r | |
1644 | \r | |
1645 | //\r | |
1646 | // The policy QUERY_USER_ON_SECURITY_VIOLATION and ALLOW_EXECUTE_ON_SECURITY_VIOLATION\r | |
1647 | // violates the UEFI spec and has been removed.\r | |
1648 | //\r | |
1649 | ASSERT (Policy != QUERY_USER_ON_SECURITY_VIOLATION && Policy != ALLOW_EXECUTE_ON_SECURITY_VIOLATION);\r | |
1650 | if (Policy == QUERY_USER_ON_SECURITY_VIOLATION || Policy == ALLOW_EXECUTE_ON_SECURITY_VIOLATION) {\r | |
1651 | CpuDeadLoop ();\r | |
1652 | }\r | |
1653 | \r | |
1654 | GetEfiGlobalVariable2 (EFI_SECURE_BOOT_MODE_NAME, (VOID**)&SecureBoot, NULL);\r | |
1655 | //\r | |
1656 | // Skip verification if SecureBoot variable doesn't exist.\r | |
1657 | //\r | |
1658 | if (SecureBoot == NULL) {\r | |
1659 | return EFI_SUCCESS;\r | |
1660 | }\r | |
1661 | \r | |
1662 | //\r | |
1663 | // Skip verification if SecureBoot is disabled but not AuditMode\r | |
1664 | //\r | |
1665 | if (*SecureBoot == SECURE_BOOT_MODE_DISABLE) {\r | |
1666 | FreePool (SecureBoot);\r | |
1667 | return EFI_SUCCESS;\r | |
1668 | }\r | |
1669 | FreePool (SecureBoot);\r | |
1670 | \r | |
1671 | //\r | |
1672 | // Read the Dos header.\r | |
1673 | //\r | |
1674 | if (FileBuffer == NULL) {\r | |
1675 | return EFI_ACCESS_DENIED;\r | |
1676 | }\r | |
1677 | \r | |
1678 | mImageBase = (UINT8 *) FileBuffer;\r | |
1679 | mImageSize = FileSize;\r | |
1680 | \r | |
1681 | ZeroMem (&ImageContext, sizeof (ImageContext));\r | |
1682 | ImageContext.Handle = (VOID *) FileBuffer;\r | |
1683 | ImageContext.ImageRead = (PE_COFF_LOADER_READ_FILE) DxeImageVerificationLibImageRead;\r | |
1684 | \r | |
1685 | //\r | |
1686 | // Get information about the image being loaded\r | |
1687 | //\r | |
1688 | PeCoffStatus = PeCoffLoaderGetImageInfo (&ImageContext);\r | |
1689 | if (RETURN_ERROR (PeCoffStatus)) {\r | |
1690 | //\r | |
1691 | // The information can't be got from the invalid PeImage\r | |
1692 | //\r | |
1693 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: PeImage invalid. Cannot retrieve image information.\n"));\r | |
1694 | goto Failed;\r | |
1695 | }\r | |
1696 | \r | |
1697 | DosHdr = (EFI_IMAGE_DOS_HEADER *) mImageBase;\r | |
1698 | if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {\r | |
1699 | //\r | |
1700 | // DOS image header is present,\r | |
1701 | // so read the PE header after the DOS image header.\r | |
1702 | //\r | |
1703 | mPeCoffHeaderOffset = DosHdr->e_lfanew;\r | |
1704 | } else {\r | |
1705 | mPeCoffHeaderOffset = 0;\r | |
1706 | }\r | |
1707 | //\r | |
1708 | // Check PE/COFF image.\r | |
1709 | //\r | |
1710 | mNtHeader.Pe32 = (EFI_IMAGE_NT_HEADERS32 *) (mImageBase + mPeCoffHeaderOffset);\r | |
1711 | if (mNtHeader.Pe32->Signature != EFI_IMAGE_NT_SIGNATURE) {\r | |
1712 | //\r | |
1713 | // It is not a valid Pe/Coff file.\r | |
1714 | //\r | |
1715 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Not a valid PE/COFF image.\n"));\r | |
1716 | goto Failed;\r | |
1717 | }\r | |
1718 | \r | |
1719 | if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {\r | |
1720 | //\r | |
1721 | // Use PE32 offset.\r | |
1722 | //\r | |
1723 | NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes;\r | |
1724 | if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {\r | |
1725 | SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];\r | |
1726 | }\r | |
1727 | } else {\r | |
1728 | //\r | |
1729 | // Use PE32+ offset.\r | |
1730 | //\r | |
1731 | NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;\r | |
1732 | if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {\r | |
1733 | SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];\r | |
1734 | }\r | |
1735 | }\r | |
1736 | \r | |
1737 | //\r | |
1738 | // Start Image Validation.\r | |
1739 | //\r | |
1740 | if (SecDataDir == NULL || SecDataDir->Size == 0) {\r | |
1741 | //\r | |
1742 | // This image is not signed. The SHA256 hash value of the image must match a record in the security database "db",\r | |
1743 | // and not be reflected in the security data base "dbx".\r | |
1744 | //\r | |
1745 | if (!HashPeImage (HASHALG_SHA256)) {\r | |
1746 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Failed to hash this image using %s.\n", mHashTypeStr));\r | |
1747 | goto Failed;\r | |
1748 | }\r | |
1749 | \r | |
1750 | if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {\r | |
1751 | //\r | |
1752 | // Image Hash is in forbidden database (DBX).\r | |
1753 | //\r | |
1754 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is not signed and %s hash of image is forbidden by DBX.\n", mHashTypeStr));\r | |
1755 | goto Failed;\r | |
1756 | }\r | |
1757 | \r | |
1758 | if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {\r | |
1759 | //\r | |
1760 | // Image Hash is in allowed database (DB).\r | |
1761 | //\r | |
1762 | return EFI_SUCCESS;\r | |
1763 | }\r | |
1764 | \r | |
1765 | //\r | |
1766 | // Image Hash is not found in both forbidden and allowed database.\r | |
1767 | //\r | |
1768 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is not signed and %s hash of image is not found in DB/DBX.\n", mHashTypeStr));\r | |
1769 | goto Failed;\r | |
1770 | }\r | |
1771 | \r | |
1772 | //\r | |
1773 | // Verify the signature of the image, multiple signatures are allowed as per PE/COFF Section 4.7\r | |
1774 | // "Attribute Certificate Table".\r | |
1775 | // The first certificate starts at offset (SecDataDir->VirtualAddress) from the start of the file.\r | |
1776 | //\r | |
1777 | for (OffSet = SecDataDir->VirtualAddress;\r | |
1778 | OffSet < (SecDataDir->VirtualAddress + SecDataDir->Size);\r | |
1779 | OffSet += (WinCertificate->dwLength + ALIGN_SIZE (WinCertificate->dwLength))) {\r | |
1780 | WinCertificate = (WIN_CERTIFICATE *) (mImageBase + OffSet);\r | |
1781 | if ((SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) <= sizeof (WIN_CERTIFICATE) ||\r | |
1782 | (SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) < WinCertificate->dwLength) {\r | |
1783 | break;\r | |
1784 | }\r | |
1785 | \r | |
1786 | //\r | |
1787 | // Verify the image's Authenticode signature, only DER-encoded PKCS#7 signed data is supported.\r | |
1788 | //\r | |
1789 | if (WinCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) {\r | |
1790 | //\r | |
1791 | // The certificate is formatted as WIN_CERTIFICATE_EFI_PKCS which is described in the\r | |
1792 | // Authenticode specification.\r | |
1793 | //\r | |
1794 | PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *) WinCertificate;\r | |
1795 | if (PkcsCertData->Hdr.dwLength <= sizeof (PkcsCertData->Hdr)) {\r | |
1796 | break;\r | |
1797 | }\r | |
1798 | AuthData = PkcsCertData->CertData;\r | |
1799 | AuthDataSize = PkcsCertData->Hdr.dwLength - sizeof(PkcsCertData->Hdr);\r | |
1800 | } else if (WinCertificate->wCertificateType == WIN_CERT_TYPE_EFI_GUID) {\r | |
1801 | //\r | |
1802 | // The certificate is formatted as WIN_CERTIFICATE_UEFI_GUID which is described in UEFI Spec.\r | |
1803 | //\r | |
1804 | WinCertUefiGuid = (WIN_CERTIFICATE_UEFI_GUID *) WinCertificate;\r | |
1805 | if (WinCertUefiGuid->Hdr.dwLength <= OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData)) {\r | |
1806 | break;\r | |
1807 | }\r | |
1808 | if (!CompareGuid (&WinCertUefiGuid->CertType, &gEfiCertPkcs7Guid)) {\r | |
1809 | continue;\r | |
1810 | }\r | |
1811 | AuthData = WinCertUefiGuid->CertData;\r | |
1812 | AuthDataSize = WinCertUefiGuid->Hdr.dwLength - OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData);\r | |
1813 | } else {\r | |
1814 | if (WinCertificate->dwLength < sizeof (WIN_CERTIFICATE)) {\r | |
1815 | break;\r | |
1816 | }\r | |
1817 | continue;\r | |
1818 | }\r | |
1819 | \r | |
1820 | HashStatus = HashPeImageByType (AuthData, AuthDataSize);\r | |
1821 | if (EFI_ERROR (HashStatus)) {\r | |
1822 | continue;\r | |
1823 | }\r | |
1824 | \r | |
1825 | //\r | |
1826 | // Check the digital signature against the revoked certificate in forbidden database (dbx).\r | |
1827 | //\r | |
1828 | if (IsForbiddenByDbx (AuthData, AuthDataSize)) {\r | |
1829 | Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED;\r | |
1830 | IsVerified = FALSE;\r | |
1831 | break;\r | |
1832 | }\r | |
1833 | \r | |
1834 | //\r | |
1835 | // Check the digital signature against the valid certificate in allowed database (db).\r | |
1836 | //\r | |
1837 | if (!IsVerified) {\r | |
1838 | if (IsAllowedByDb (AuthData, AuthDataSize)) {\r | |
1839 | IsVerified = TRUE;\r | |
1840 | }\r | |
1841 | }\r | |
1842 | \r | |
1843 | //\r | |
1844 | // Check the image's hash value.\r | |
1845 | //\r | |
1846 | if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {\r | |
1847 | Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND;\r | |
1848 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed but %s hash of image is found in DBX.\n", mHashTypeStr));\r | |
1849 | IsVerified = FALSE;\r | |
1850 | break;\r | |
1851 | }\r | |
1852 | if (!IsVerified) {\r | |
1853 | if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {\r | |
1854 | IsVerified = TRUE;\r | |
1855 | } else {\r | |
1856 | DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed but signature is not allowed by DB and %s hash of image is not found in DB/DBX.\n", mHashTypeStr));\r | |
1857 | }\r | |
1858 | }\r | |
1859 | }\r | |
1860 | \r | |
1861 | if (OffSet != (SecDataDir->VirtualAddress + SecDataDir->Size)) {\r | |
1862 | //\r | |
1863 | // The Size in Certificate Table or the attribute certificate table is corrupted.\r | |
1864 | //\r | |
1865 | IsVerified = FALSE;\r | |
1866 | }\r | |
1867 | \r | |
1868 | if (IsVerified) {\r | |
1869 | return EFI_SUCCESS;\r | |
1870 | }\r | |
1871 | if (Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED || Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND) {\r | |
1872 | //\r | |
1873 | // Get image hash value as signature of executable.\r | |
1874 | //\r | |
1875 | SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize;\r | |
1876 | SignatureList = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize);\r | |
1877 | if (SignatureList == NULL) {\r | |
1878 | SignatureListSize = 0;\r | |
1879 | goto Failed;\r | |
1880 | }\r | |
1881 | SignatureList->SignatureHeaderSize = 0;\r | |
1882 | SignatureList->SignatureListSize = (UINT32) SignatureListSize;\r | |
1883 | SignatureList->SignatureSize = (UINT32) (sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize);\r | |
1884 | CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID));\r | |
1885 | Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST));\r | |
1886 | CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize);\r | |
1887 | }\r | |
1888 | \r | |
1889 | Failed:\r | |
1890 | //\r | |
1891 | // Policy decides to defer or reject the image; add its information in image\r | |
1892 | // executable information table in either case.\r | |
1893 | //\r | |
1894 | NameStr = ConvertDevicePathToText (File, FALSE, TRUE);\r | |
1895 | AddImageExeInfo (Action, NameStr, File, SignatureList, SignatureListSize);\r | |
1896 | if (NameStr != NULL) {\r | |
1897 | DEBUG ((DEBUG_INFO, "The image doesn't pass verification: %s\n", NameStr));\r | |
1898 | FreePool(NameStr);\r | |
1899 | }\r | |
1900 | \r | |
1901 | if (SignatureList != NULL) {\r | |
1902 | FreePool (SignatureList);\r | |
1903 | }\r | |
1904 | \r | |
1905 | if (Policy == DEFER_EXECUTE_ON_SECURITY_VIOLATION) {\r | |
1906 | return EFI_SECURITY_VIOLATION;\r | |
1907 | }\r | |
1908 | return EFI_ACCESS_DENIED;\r | |
1909 | }\r | |
1910 | \r | |
1911 | /**\r | |
1912 | On Ready To Boot Services Event notification handler.\r | |
1913 | \r | |
1914 | Add the image execution information table if it is not in system configuration table.\r | |
1915 | \r | |
1916 | @param[in] Event Event whose notification function is being invoked\r | |
1917 | @param[in] Context Pointer to the notification function's context\r | |
1918 | \r | |
1919 | **/\r | |
1920 | VOID\r | |
1921 | EFIAPI\r | |
1922 | OnReadyToBoot (\r | |
1923 | IN EFI_EVENT Event,\r | |
1924 | IN VOID *Context\r | |
1925 | )\r | |
1926 | {\r | |
1927 | EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable;\r | |
1928 | UINTN ImageExeInfoTableSize;\r | |
1929 | \r | |
1930 | EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable);\r | |
1931 | if (ImageExeInfoTable != NULL) {\r | |
1932 | return;\r | |
1933 | }\r | |
1934 | \r | |
1935 | ImageExeInfoTableSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE);\r | |
1936 | ImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize);\r | |
1937 | if (ImageExeInfoTable == NULL) {\r | |
1938 | return ;\r | |
1939 | }\r | |
1940 | \r | |
1941 | ImageExeInfoTable->NumberOfImages = 0;\r | |
1942 | gBS->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID *) ImageExeInfoTable);\r | |
1943 | \r | |
1944 | }\r | |
1945 | \r | |
1946 | /**\r | |
1947 | Register security measurement handler.\r | |
1948 | \r | |
1949 | @param ImageHandle ImageHandle of the loaded driver.\r | |
1950 | @param SystemTable Pointer to the EFI System Table.\r | |
1951 | \r | |
1952 | @retval EFI_SUCCESS The handlers were registered successfully.\r | |
1953 | **/\r | |
1954 | EFI_STATUS\r | |
1955 | EFIAPI\r | |
1956 | DxeImageVerificationLibConstructor (\r | |
1957 | IN EFI_HANDLE ImageHandle,\r | |
1958 | IN EFI_SYSTEM_TABLE *SystemTable\r | |
1959 | )\r | |
1960 | {\r | |
1961 | EFI_EVENT Event;\r | |
1962 | \r | |
1963 | //\r | |
1964 | // Register the event to publish the image execution table.\r | |
1965 | //\r | |
1966 | EfiCreateEventReadyToBootEx (\r | |
1967 | TPL_CALLBACK,\r | |
1968 | OnReadyToBoot,\r | |
1969 | NULL,\r | |
1970 | &Event\r | |
1971 | );\r | |
1972 | \r | |
1973 | return RegisterSecurity2Handler (\r | |
1974 | DxeImageVerificationHandler,\r | |
1975 | EFI_AUTH_OPERATION_VERIFY_IMAGE | EFI_AUTH_OPERATION_IMAGE_REQUIRED\r | |
1976 | );\r | |
1977 | }\r |