1 /** @file 2 This module implements measuring PeCoff image for Tcg2 Protocol. 3 4 Caution: This file requires additional review when modified. 5 This driver will have external input - PE/COFF image. 6 This external input must be validated carefully to avoid security issue like 7 buffer overflow, integer overflow. 8 9 Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR> 10 This program and the accompanying materials 11 are licensed and made available under the terms and conditions of the BSD License 12 which accompanies this distribution. The full text of the license may be found at 13 http://opensource.org/licenses/bsd-license.php 14 15 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 16 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 17 18 **/ 19 20 #include <PiDxe.h> 21 22 #include <Library/BaseLib.h> 23 #include <Library/DebugLib.h> 24 #include <Library/BaseMemoryLib.h> 25 #include <Library/MemoryAllocationLib.h> 26 #include <Library/DevicePathLib.h> 27 #include <Library/UefiBootServicesTableLib.h> 28 #include <Library/PeCoffLib.h> 29 #include <Library/Tpm2CommandLib.h> 30 #include <Library/HashLib.h> 31 32 UINTN mTcg2DxeImageSize = 0; 33 34 /** 35 Reads contents of a PE/COFF image in memory buffer. 36 37 Caution: This function may receive untrusted input. 38 PE/COFF image is external input, so this function will make sure the PE/COFF image content 39 read is within the image buffer. 40 41 @param FileHandle Pointer to the file handle to read the PE/COFF image. 42 @param FileOffset Offset into the PE/COFF image to begin the read operation. 43 @param ReadSize On input, the size in bytes of the requested read operation. 44 On output, the number of bytes actually read. 45 @param Buffer Output buffer that contains the data read from the PE/COFF image. 46 47 @retval EFI_SUCCESS The specified portion of the PE/COFF image was read and the size 48 **/ 49 EFI_STATUS 50 EFIAPI 51 Tcg2DxeImageRead ( 52 IN VOID *FileHandle, 53 IN UINTN FileOffset, 54 IN OUT UINTN *ReadSize, 55 OUT VOID *Buffer 56 ) 57 { 58 UINTN EndPosition; 59 60 if (FileHandle == NULL || ReadSize == NULL || Buffer == NULL) { 61 return EFI_INVALID_PARAMETER; 62 } 63 64 if (MAX_ADDRESS - FileOffset < *ReadSize) { 65 return EFI_INVALID_PARAMETER; 66 } 67 68 EndPosition = FileOffset + *ReadSize; 69 if (EndPosition > mTcg2DxeImageSize) { 70 *ReadSize = (UINT32)(mTcg2DxeImageSize - FileOffset); 71 } 72 73 if (FileOffset >= mTcg2DxeImageSize) { 74 *ReadSize = 0; 75 } 76 77 CopyMem (Buffer, (UINT8 *)((UINTN) FileHandle + FileOffset), *ReadSize); 78 79 return EFI_SUCCESS; 80 } 81 82 /** 83 Measure PE image into TPM log based on the authenticode image hashing in 84 PE/COFF Specification 8.0 Appendix A. 85 86 Caution: This function may receive untrusted input. 87 PE/COFF image is external input, so this function will validate its data structure 88 within this image buffer before use. 89 90 Notes: PE/COFF image is checked by BasePeCoffLib PeCoffLoaderGetImageInfo(). 91 92 @param[in] PCRIndex TPM PCR index 93 @param[in] ImageAddress Start address of image buffer. 94 @param[in] ImageSize Image size 95 @param[out] DigestList Digeest list of this image. 96 97 @retval EFI_SUCCESS Successfully measure image. 98 @retval EFI_OUT_OF_RESOURCES No enough resource to measure image. 99 @retval other error value 100 **/ 101 EFI_STATUS 102 MeasurePeImageAndExtend ( 103 IN UINT32 PCRIndex, 104 IN EFI_PHYSICAL_ADDRESS ImageAddress, 105 IN UINTN ImageSize, 106 OUT TPML_DIGEST_VALUES *DigestList 107 ) 108 { 109 EFI_STATUS Status; 110 EFI_IMAGE_DOS_HEADER *DosHdr; 111 UINT32 PeCoffHeaderOffset; 112 EFI_IMAGE_SECTION_HEADER *Section; 113 UINT8 *HashBase; 114 UINTN HashSize; 115 UINTN SumOfBytesHashed; 116 EFI_IMAGE_SECTION_HEADER *SectionHeader; 117 UINTN Index; 118 UINTN Pos; 119 UINT16 Magic; 120 EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION Hdr; 121 UINT32 NumberOfRvaAndSizes; 122 UINT32 CertSize; 123 HASH_HANDLE HashHandle; 124 PE_COFF_LOADER_IMAGE_CONTEXT ImageContext; 125 126 HashHandle = 0xFFFFFFFF; // Know bad value 127 128 Status = EFI_UNSUPPORTED; 129 SectionHeader = NULL; 130 131 // 132 // Check PE/COFF image 133 // 134 ZeroMem (&ImageContext, sizeof (ImageContext)); 135 ImageContext.Handle = (VOID *) (UINTN) ImageAddress; 136 mTcg2DxeImageSize = ImageSize; 137 ImageContext.ImageRead = (PE_COFF_LOADER_READ_FILE) Tcg2DxeImageRead; 138 139 // 140 // Get information about the image being loaded 141 // 142 Status = PeCoffLoaderGetImageInfo (&ImageContext); 143 if (EFI_ERROR (Status)) { 144 // 145 // The information can't be got from the invalid PeImage 146 // 147 DEBUG ((DEBUG_INFO, "Tcg2Dxe: PeImage invalid. Cannot retrieve image information.\n")); 148 goto Finish; 149 } 150 151 DosHdr = (EFI_IMAGE_DOS_HEADER *) (UINTN) ImageAddress; 152 PeCoffHeaderOffset = 0; 153 if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) { 154 PeCoffHeaderOffset = DosHdr->e_lfanew; 155 } 156 157 Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)((UINT8 *) (UINTN) ImageAddress + PeCoffHeaderOffset); 158 if (Hdr.Pe32->Signature != EFI_IMAGE_NT_SIGNATURE) { 159 Status = EFI_UNSUPPORTED; 160 goto Finish; 161 } 162 163 // 164 // PE/COFF Image Measurement 165 // 166 // NOTE: The following codes/steps are based upon the authenticode image hashing in 167 // PE/COFF Specification 8.0 Appendix A. 168 // 169 // 170 171 // 1. Load the image header into memory. 172 173 // 2. Initialize a SHA hash context. 174 175 Status = HashStart (&HashHandle); 176 if (EFI_ERROR (Status)) { 177 goto Finish; 178 } 179 180 // 181 // Measuring PE/COFF Image Header; 182 // But CheckSum field and SECURITY data directory (certificate) are excluded 183 // 184 if (Hdr.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && Hdr.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { 185 // 186 // NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value 187 // in the PE/COFF Header. If the MachineType is Itanium(IA64) and the 188 // Magic value in the OptionalHeader is EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC 189 // then override the magic value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC 190 // 191 Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC; 192 } else { 193 // 194 // Get the magic value from the PE/COFF Optional Header 195 // 196 Magic = Hdr.Pe32->OptionalHeader.Magic; 197 } 198 199 // 200 // 3. Calculate the distance from the base of the image header to the image checksum address. 201 // 4. Hash the image header from its base to beginning of the image checksum. 202 // 203 HashBase = (UINT8 *) (UINTN) ImageAddress; 204 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { 205 // 206 // Use PE32 offset 207 // 208 NumberOfRvaAndSizes = Hdr.Pe32->OptionalHeader.NumberOfRvaAndSizes; 209 HashSize = (UINTN) ((UINT8 *)(&Hdr.Pe32->OptionalHeader.CheckSum) - HashBase); 210 } else { 211 // 212 // Use PE32+ offset 213 // 214 NumberOfRvaAndSizes = Hdr.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes; 215 HashSize = (UINTN) ((UINT8 *)(&Hdr.Pe32Plus->OptionalHeader.CheckSum) - HashBase); 216 } 217 218 Status = HashUpdate (HashHandle, HashBase, HashSize); 219 if (EFI_ERROR (Status)) { 220 goto Finish; 221 } 222 223 // 224 // 5. Skip over the image checksum (it occupies a single ULONG). 225 // 226 if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) { 227 // 228 // 6. Since there is no Cert Directory in optional header, hash everything 229 // from the end of the checksum to the end of image header. 230 // 231 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { 232 // 233 // Use PE32 offset. 234 // 235 HashBase = (UINT8 *) &Hdr.Pe32->OptionalHeader.CheckSum + sizeof (UINT32); 236 HashSize = Hdr.Pe32->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - ImageAddress); 237 } else { 238 // 239 // Use PE32+ offset. 240 // 241 HashBase = (UINT8 *) &Hdr.Pe32Plus->OptionalHeader.CheckSum + sizeof (UINT32); 242 HashSize = Hdr.Pe32Plus->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - ImageAddress); 243 } 244 245 if (HashSize != 0) { 246 Status = HashUpdate (HashHandle, HashBase, HashSize); 247 if (EFI_ERROR (Status)) { 248 goto Finish; 249 } 250 } 251 } else { 252 // 253 // 7. Hash everything from the end of the checksum to the start of the Cert Directory. 254 // 255 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { 256 // 257 // Use PE32 offset 258 // 259 HashBase = (UINT8 *) &Hdr.Pe32->OptionalHeader.CheckSum + sizeof (UINT32); 260 HashSize = (UINTN) ((UINT8 *)(&Hdr.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - HashBase); 261 } else { 262 // 263 // Use PE32+ offset 264 // 265 HashBase = (UINT8 *) &Hdr.Pe32Plus->OptionalHeader.CheckSum + sizeof (UINT32); 266 HashSize = (UINTN) ((UINT8 *)(&Hdr.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - HashBase); 267 } 268 269 if (HashSize != 0) { 270 Status = HashUpdate (HashHandle, HashBase, HashSize); 271 if (EFI_ERROR (Status)) { 272 goto Finish; 273 } 274 } 275 276 // 277 // 8. Skip over the Cert Directory. (It is sizeof(IMAGE_DATA_DIRECTORY) bytes.) 278 // 9. Hash everything from the end of the Cert Directory to the end of image header. 279 // 280 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { 281 // 282 // Use PE32 offset 283 // 284 HashBase = (UINT8 *) &Hdr.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1]; 285 HashSize = Hdr.Pe32->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - ImageAddress); 286 } else { 287 // 288 // Use PE32+ offset 289 // 290 HashBase = (UINT8 *) &Hdr.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1]; 291 HashSize = Hdr.Pe32Plus->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - ImageAddress); 292 } 293 294 if (HashSize != 0) { 295 Status = HashUpdate (HashHandle, HashBase, HashSize); 296 if (EFI_ERROR (Status)) { 297 goto Finish; 298 } 299 } 300 } 301 302 // 303 // 10. Set the SUM_OF_BYTES_HASHED to the size of the header 304 // 305 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { 306 // 307 // Use PE32 offset 308 // 309 SumOfBytesHashed = Hdr.Pe32->OptionalHeader.SizeOfHeaders; 310 } else { 311 // 312 // Use PE32+ offset 313 // 314 SumOfBytesHashed = Hdr.Pe32Plus->OptionalHeader.SizeOfHeaders; 315 } 316 317 // 318 // 11. Build a temporary table of pointers to all the IMAGE_SECTION_HEADER 319 // structures in the image. The 'NumberOfSections' field of the image 320 // header indicates how big the table should be. Do not include any 321 // IMAGE_SECTION_HEADERs in the table whose 'SizeOfRawData' field is zero. 322 // 323 SectionHeader = (EFI_IMAGE_SECTION_HEADER *) AllocateZeroPool (sizeof (EFI_IMAGE_SECTION_HEADER) * Hdr.Pe32->FileHeader.NumberOfSections); 324 if (SectionHeader == NULL) { 325 Status = EFI_OUT_OF_RESOURCES; 326 goto Finish; 327 } 328 329 // 330 // 12. Using the 'PointerToRawData' in the referenced section headers as 331 // a key, arrange the elements in the table in ascending order. In other 332 // words, sort the section headers according to the disk-file offset of 333 // the section. 334 // 335 Section = (EFI_IMAGE_SECTION_HEADER *) ( 336 (UINT8 *) (UINTN) ImageAddress + 337 PeCoffHeaderOffset + 338 sizeof(UINT32) + 339 sizeof(EFI_IMAGE_FILE_HEADER) + 340 Hdr.Pe32->FileHeader.SizeOfOptionalHeader 341 ); 342 for (Index = 0; Index < Hdr.Pe32->FileHeader.NumberOfSections; Index++) { 343 Pos = Index; 344 while ((Pos > 0) && (Section->PointerToRawData < SectionHeader[Pos - 1].PointerToRawData)) { 345 CopyMem (&SectionHeader[Pos], &SectionHeader[Pos - 1], sizeof(EFI_IMAGE_SECTION_HEADER)); 346 Pos--; 347 } 348 CopyMem (&SectionHeader[Pos], Section, sizeof(EFI_IMAGE_SECTION_HEADER)); 349 Section += 1; 350 } 351 352 // 353 // 13. Walk through the sorted table, bring the corresponding section 354 // into memory, and hash the entire section (using the 'SizeOfRawData' 355 // field in the section header to determine the amount of data to hash). 356 // 14. Add the section's 'SizeOfRawData' to SUM_OF_BYTES_HASHED . 357 // 15. Repeat steps 13 and 14 for all the sections in the sorted table. 358 // 359 for (Index = 0; Index < Hdr.Pe32->FileHeader.NumberOfSections; Index++) { 360 Section = (EFI_IMAGE_SECTION_HEADER *) &SectionHeader[Index]; 361 if (Section->SizeOfRawData == 0) { 362 continue; 363 } 364 HashBase = (UINT8 *) (UINTN) ImageAddress + Section->PointerToRawData; 365 HashSize = (UINTN) Section->SizeOfRawData; 366 367 Status = HashUpdate (HashHandle, HashBase, HashSize); 368 if (EFI_ERROR (Status)) { 369 goto Finish; 370 } 371 372 SumOfBytesHashed += HashSize; 373 } 374 375 // 376 // 16. If the file size is greater than SUM_OF_BYTES_HASHED, there is extra 377 // data in the file that needs to be added to the hash. This data begins 378 // at file offset SUM_OF_BYTES_HASHED and its length is: 379 // FileSize - (CertDirectory->Size) 380 // 381 if (ImageSize > SumOfBytesHashed) { 382 HashBase = (UINT8 *) (UINTN) ImageAddress + SumOfBytesHashed; 383 384 if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) { 385 CertSize = 0; 386 } else { 387 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { 388 // 389 // Use PE32 offset. 390 // 391 CertSize = Hdr.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size; 392 } else { 393 // 394 // Use PE32+ offset. 395 // 396 CertSize = Hdr.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size; 397 } 398 } 399 400 if (ImageSize > CertSize + SumOfBytesHashed) { 401 HashSize = (UINTN) (ImageSize - CertSize - SumOfBytesHashed); 402 403 Status = HashUpdate (HashHandle, HashBase, HashSize); 404 if (EFI_ERROR (Status)) { 405 goto Finish; 406 } 407 } else if (ImageSize < CertSize + SumOfBytesHashed) { 408 Status = EFI_UNSUPPORTED; 409 goto Finish; 410 } 411 } 412 413 // 414 // 17. Finalize the SHA hash. 415 // 416 Status = HashCompleteAndExtend (HashHandle, PCRIndex, NULL, 0, DigestList); 417 if (EFI_ERROR (Status)) { 418 goto Finish; 419 } 420 421 Finish: 422 if (SectionHeader != NULL) { 423 FreePool (SectionHeader); 424 } 425 426 return Status; 427 } 428