The Tor Browser / file revision

 // 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

 //

 // Author: Dan Waylonis

 #include <fcntl.h>

 #include <string.h>

 #include <unistd.h>

 #include "common/mac/file_id.h"

 #include "common/mac/macho_id.h"

 using MacFileUtilities::MachoID;

 namespace google_breakpad {

 FileID::FileID(const char *path) {

   strlcpy(path_, path, sizeof(path_));

 }

 bool FileID::FileIdentifier(unsigned char identifier[16]) {

   int fd = open(path_, O_RDONLY);

   if (fd == -1)

     return false;

   MD5Context md5;

   MD5Init(&md5);

   // Read 4k x 2 bytes at a time.  This is faster than just 4k bytes, but

   // doesn't seem to be an unreasonable size for the stack.

   unsigned char buffer[4096 * 2];

   size_t buffer_size = sizeof(buffer);

   while ((buffer_size = read(fd, buffer, buffer_size) > 0)) {

     MD5Update(&md5, buffer, buffer_size);

   }

   close(fd);

   MD5Final(identifier, &md5);

   return true;

 }

 bool FileID::MachoIdentifier(cpu_type_t cpu_type,

                              cpu_subtype_t cpu_subtype,

                              unsigned char identifier[16]) {

   MachoID macho(path_);

   if (macho.UUIDCommand(cpu_type, cpu_subtype, identifier))

     return true;

   return macho.MD5(cpu_type, cpu_subtype, identifier);

 }

 // static

 void FileID::ConvertIdentifierToString(const unsigned char identifier[16],

                                        char *buffer, int buffer_length) {

   int buffer_idx = 0;

   for (int idx = 0; (buffer_idx < buffer_length) && (idx < 16); ++idx) {

     int hi = (identifier[idx] >> 4) & 0x0F;

     int lo = (identifier[idx]) & 0x0F;

     if (idx == 4 || idx == 6 || idx == 8 || idx == 10)

       buffer[buffer_idx++] = '-';

     buffer[buffer_idx++] =

         static_cast<char>((hi >= 10) ? ('A' + hi - 10) : ('0' + hi));

     buffer[buffer_idx++] =

         static_cast<char>((lo >= 10) ? ('A' + lo - 10) : ('0' + lo));

   }

   // NULL terminate

   buffer[(buffer_idx < buffer_length) ? buffer_idx : buffer_idx - 1] = 0;

 }

 }  // namespace google_breakpad