iPhone BLE Privacy Feature

When you scan for BLE devices, you probably notice a lot of no name devices.
More likely, there are iPhones. It’s good privacy feature as you don’t want to advertise your phone name to everyone.

In addition, Apple uses new Bluetooth 4.0 Privacy Feature, which changes its ID on a frequent basis. Thus, you can’t track.

  • The only way to tell if it’s iPhone is using Manufacturer data. But you can’t track a particular one.
  • Per Bluetooth Core Specification, Manufacturer data is type 0xFF.
    Note: You can see this value from Core Bluetooth API \ didDiscoverPeripheral function \ advertisementData \ kCBAdvDataManufacturerData.
  • 1st 2-byte is Company ID in little endian.
  • If the is “0x004C”, which indicates Apple, Inc.
  • Complete list here: https://www.bluetooth.org/en-us/specification/assigned-numbers/company-identifiers
iPhone BLE Privacy Feature

Notes on Apple Core Bluetooth Peripheral ID

  • The only peripheral ID that Core Bluetooth API offers after discovery is CBPeripheral.identifier.
  • Not MAC address.
    You can’t get MAC address via Core Bluetooth. There is no public API for this. If this is an internal or jailbreak application you can get the value of the kLockdownBluetoothAddressKey key via liblockdown.dylib.
  • It’s obtained via callback function didDiscoverPeripheral. (iPhone acts as central device)
  • Type is NSUUID, not CBUUID. UUID is deprecated as of iOS 7.0.
  • identifier has been moved to CBPeer class, which is base class of CBPeripheral. So net effect is the same.
  • A different central will return a different id for the same peripheral.
  • A central will return the same id for a peripheral. Thus, it can be stored and used later per Apple doc.
    However, I don’t know how long it will return the same id.
    Important: assuming the peripheral doesn’t use Bluetooth 4.0 Privacy feature, which changes its ID periodically.
  • Peripheral MAC & central id (& possible time) is used (by Core Bluetooth) in generating this CBPeripheral.identifier.
Notes on Apple Core Bluetooth Peripheral ID

git svn broken in OS X Yosemite

Type ‘git svn’ command, you will get the error below:

$ git svn
Can't locate SVN/Core.pm in @INC (you may need to install the SVN::Core module) (@INC contains: /usr/local/git/lib/perl5/site_perl/5.18.2/darwin-thread-multi-2level /usr/local/git/lib/perl5/site_perl/5.18.2 /usr/local/git/lib/perl5/site_perl /Library/Perl/5.18/darwin-thread-multi-2level /Library/Perl/5.18 /Network/Library/Perl/5.18/darwin-thread-multi-2level /Network/Library/Perl/5.18 /Library/Perl/Updates/5.18.2 /System/Library/Perl/5.18/darwin-thread-multi-2level /System/Library/Perl/5.18 /System/Library/Perl/Extras/5.18/darwin-thread-multi-2level /System/Library/Perl/Extras/5.18 .) at /usr/local/git/lib/perl5/site_perl/Git/SVN/Utils.pm line 6.
BEGIN failed--compilation aborted at /usr/local/git/lib/perl5/site_perl/Git/SVN/Utils.pm line 6.
Compilation failed in require at /usr/local/git/lib/perl5/site_perl/Git/SVN.pm line 26.
BEGIN failed--compilation aborted at /usr/local/git/lib/perl5/site_perl/Git/SVN.pm line 33.
Compilation failed in require at /usr/local/git/libexec/git-core/git-svn line 25.
BEGIN failed--compilation aborted at /usr/local/git/libexec/git-core/git-svn line 25.

Solution

The problem is that prerequisite Perl libraries which are missing.
You can use existing Xcode Perl libraries by using the below 2 commands:

$ sudo ln -s /Applications/Xcode.app/Contents/Developer/Library/Perl/5.18/darwin-thread-multi-2level/SVN /System/Library/Perl/Extras/5.18/SVN
$ sudo ln -s /Applications/Xcode.app/Contents/Developer/Library/Perl/5.18/darwin-thread-multi-2level/auto/SVN/ /System/Library/Perl/Extras/5.18/auto/SVN

Notes
– If you have OS X Mavericks, change 5.18 in the above commands to 5.16.
– If you have OS X Mountain Lion, change 5.18 in the above commands to 5.12.
– You must install Xcode Command Line Tools in advance.
– If you don’t run the 2nd command, you will get the error below:
$ git svn
Can't locate loadable object for module SVN::_Core in @INC (@INC contains: /usr/local/git/lib/perl5/site_perl/5.18.2/darwin-thread-multi-2level /usr/local/git/lib/perl5/site_perl/5.18.2 /usr/local/git/lib/perl5/site_perl /Library/Perl/5.18/darwin-thread-multi-2level /Library/Perl/5.18 /Network/Library/Perl/5.18/darwin-thread-multi-2level /Network/Library/Perl/5.18 /Library/Perl/Updates/5.18.2 /System/Library/Perl/5.18/darwin-thread-multi-2level /System/Library/Perl/5.18 /System/Library/Perl/Extras/5.18/darwin-thread-multi-2level /System/Library/Perl/Extras/5.18 .) at /System/Library/Perl/Extras/5.18/SVN/Base.pm line 59.
BEGIN failed--compilation aborted at /System/Library/Perl/Extras/5.18/SVN/Core.pm line 5.
Compilation failed in require at /usr/local/git/lib/perl5/site_perl/Git/SVN/Utils.pm line 6.
BEGIN failed--compilation aborted at /usr/local/git/lib/perl5/site_perl/Git/SVN/Utils.pm line 6.
Compilation failed in require at /usr/local/git/lib/perl5/site_perl/Git/SVN.pm line 26.
BEGIN failed--compilation aborted at /usr/local/git/lib/perl5/site_perl/Git/SVN.pm line 33.
Compilation failed in require at /usr/local/git/libexec/git-core/git-svn line 25.
BEGIN failed--compilation aborted at /usr/local/git/libexec/git-core/git-svn line 25.

– If you don’t want to make symbolic link, you can install using this command:
brew install git svn

git svn broken in OS X Yosemite

Swift programming language disambiguation

Recent Apple’s announcement of new Swift programming language caused confusion among developers. Swift, which should be called Apple Swift, is new programing language from Apple. Other Swift languages are not Apple Swift.

Apple Swift has JavaScript-like syntax and is similar to Rust http://www.rust-lang.org.

Swift programming language disambiguation