The Tor Browser: toolkit/crashreporter/google-breakpad/src/common/linux/file

toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc@129ffea94266 (annotated)

toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 // Copyright (c) 2006, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 // file_id.cc: Return a unique identifier for a file
 //
 // See file_id.h for documentation
 //
 #include "common/linux/file_id.h"
 #include <arpa/inet.h>
 #include <assert.h>
 #include <string.h>
 #include <algorithm>
 #include "common/linux/elfutils.h"
 #include "common/linux/linux_libc_support.h"
 #include "common/linux/memory_mapped_file.h"
 #include "third_party/lss/linux_syscall_support.h"
 namespace google_breakpad {
 #ifndef NT_GNU_BUILD_ID
 #define NT_GNU_BUILD_ID 3
 #endif
 FileID::FileID(const char* path) {
   strncpy(path_, path, sizeof(path_));
 }
 // ELF note name and desc are 32-bits word padded.
 #define NOTE_PADDING(a) ((a + 3) & ~3)
 // These functions are also used inside the crashed process, so be safe
 // and use the syscall/libc wrappers instead of direct syscalls or libc.
 template<typename ElfClass>
 static bool ElfClassBuildIDNoteIdentifier(const void *section, int length,
                                           uint8_t identifier[kMDGUIDSize]) {
   typedef typename ElfClass::Nhdr Nhdr;
   const void* section_end = reinterpret_cast<const char*>(section) + length;
   const Nhdr* note_header = reinterpret_cast<const Nhdr*>(section);
   while (reinterpret_cast<const void *>(note_header) < section_end) {
     if (note_header->n_type == NT_GNU_BUILD_ID)
       break;
     note_header = reinterpret_cast<const Nhdr*>(
                   reinterpret_cast<const char*>(note_header) + sizeof(Nhdr) +
                   NOTE_PADDING(note_header->n_namesz) +
                   NOTE_PADDING(note_header->n_descsz));
   }
   if (reinterpret_cast<const void *>(note_header) >= section_end ||
       note_header->n_descsz == 0) {
     return false;
   }
   const char* build_id = reinterpret_cast<const char*>(note_header) +
     sizeof(Nhdr) + NOTE_PADDING(note_header->n_namesz);
   // Copy as many bits of the build ID as will fit
   // into the GUID space.
   my_memset(identifier, 0, kMDGUIDSize);
   memcpy(identifier, build_id,
          std::min(kMDGUIDSize, (size_t)note_header->n_descsz));
   return true;
 }
 // Attempt to locate a .note.gnu.build-id section in an ELF binary
 // and copy as many bytes of it as will fit into |identifier|.
 static bool FindElfBuildIDNote(const void *elf_mapped_base,
                                uint8_t identifier[kMDGUIDSize]) {
   void* note_section;
   int note_size, elfclass;
   if ((!FindElfSegment(elf_mapped_base, PT_NOTE,
                        (const void**)&note_section, &note_size, &elfclass) ||
       note_size == 0)  &&
       (!FindElfSection(elf_mapped_base, ".note.gnu.build-id", SHT_NOTE,
                        (const void**)&note_section, &note_size, &elfclass) ||
       note_size == 0)) {
     return false;
   }
   if (elfclass == ELFCLASS32) {
     return ElfClassBuildIDNoteIdentifier<ElfClass32>(note_section, note_size,
                                                      identifier);
   } else if (elfclass == ELFCLASS64) {
     return ElfClassBuildIDNoteIdentifier<ElfClass64>(note_section, note_size,
                                                      identifier);
   }
   return false;
 }
 // Attempt to locate the .text section of an ELF binary and generate
 // a simple hash by XORing the first page worth of bytes into |identifier|.
 static bool HashElfTextSection(const void *elf_mapped_base,
                                uint8_t identifier[kMDGUIDSize]) {
   void* text_section;
   int text_size;
   if (!FindElfSection(elf_mapped_base, ".text", SHT_PROGBITS,
                       (const void**)&text_section, &text_size, NULL) ||
       text_size == 0) {
     return false;
   }
   my_memset(identifier, 0, kMDGUIDSize);
   const uint8_t* ptr = reinterpret_cast<const uint8_t*>(text_section);
   const uint8_t* ptr_end = ptr + std::min(text_size, 4096);
   while (ptr < ptr_end) {
     for (unsigned i = 0; i < kMDGUIDSize; i++)
       identifier[i] ^= ptr[i];
     ptr += kMDGUIDSize;
   }
   return true;
 }
 // static
 bool FileID::ElfFileIdentifierFromMappedFile(const void* base,
                                              uint8_t identifier[kMDGUIDSize]) {
   // Look for a build id note first.
   if (FindElfBuildIDNote(base, identifier))
     return true;
   // Fall back on hashing the first page of the text section.
   return HashElfTextSection(base, identifier);
 }
 bool FileID::ElfFileIdentifier(uint8_t identifier[kMDGUIDSize]) {
   MemoryMappedFile mapped_file(path_);
   if (!mapped_file.data())  // Should probably check if size >= ElfW(Ehdr)?
     return false;
   return ElfFileIdentifierFromMappedFile(mapped_file.data(), identifier);
 }
 // static
 void FileID::ConvertIdentifierToString(const uint8_t identifier[kMDGUIDSize],
                                        char* buffer, int buffer_length) {
   uint8_t identifier_swapped[kMDGUIDSize];
   // Endian-ness swap to match dump processor expectation.
   memcpy(identifier_swapped, identifier, kMDGUIDSize);
   uint32_t* data1 = reinterpret_cast<uint32_t*>(identifier_swapped);
   *data1 = htonl(*data1);
   uint16_t* data2 = reinterpret_cast<uint16_t*>(identifier_swapped + 4);
   *data2 = htons(*data2);
   uint16_t* data3 = reinterpret_cast<uint16_t*>(identifier_swapped + 6);
   *data3 = htons(*data3);
   int buffer_idx = 0;
   for (unsigned int idx = 0;
        (buffer_idx < buffer_length) && (idx < kMDGUIDSize);
        ++idx) {
     int hi = (identifier_swapped[idx] >> 4) & 0x0F;
     int lo = (identifier_swapped[idx]) & 0x0F;
     if (idx == 4 || idx == 6 || idx == 8 || idx == 10)
       buffer[buffer_idx++] = '-';
     buffer[buffer_idx++] = (hi >= 10) ? 'A' + hi - 10 : '0' + hi;
     buffer[buffer_idx++] = (lo >= 10) ? 'A' + lo - 10 : '0' + lo;
   }
   // NULL terminate
   buffer[(buffer_idx < buffer_length) ? buffer_idx : buffer_idx - 1] = 0;
 }
 }  // namespace google_breakpad

The Tor Browser / annotate

toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc@129ffea94266 (annotated)

toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc