text: // 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
  