NFC, or Near Field Communication, is a technology that was recently added to the iPhone 6 and 6 Plus in order to implement Apple Pay. The NFC chip included on these devices is the PN548 by NXP Semiconductors. It is similar to the chip used in the Galaxy Nexus[1], and possibly other Android devices.
Apple's implementation of NFC is split into a number of binaries, found only on iPhone7,1 and iPhone7,2 devices:
- /usr/lib/PN548.dylib
- /usr/lib/PN548_API.dylib
- /usr/lib/PN548_HAL.dylib
- /usr/lib/libnfshared.dylib
- /usr/libexec/nfcd
- /System/Library/PrivateFrameworks/NearField.framework
Passbook uses NearField.framework to communicate with nfcd, and nfcd uses the NFC library provided NXP to communicate with the PN548 device. PN548.dylb is NXP's libnfc-nxp, which is open source[2] as a part of Android. PN548_API.dylib is written on top of PN548.dylib, abstracting away the full functionality of libnfc into a CoreFoundation style API named NFDriver for the express purpose of card emulation.
NFCD
nfcd is a daemon running under the mobile user. It handles the communications between Passkit and the underlying hardware and libraries.
The core objects in it are:
- NFDaemon
- NFFieldDetectController
- NFCoreTelephonyConnection
- NFPowerManager
- NFAbstractController
- NFCardEmulationController
- NFSecureElementController
NFDaemon - (void)XPCConnection:(id) didReceiveCommand:(id)
Supported XPC Commands are:
1 = q_registerConnection:info: 2 = q_unregisterConnection: 3-64 = send command to SE controller 65 = q_updateSecureElementPowerState 66 = _seIsInRestrictedMode 67 = restrictedModeChanged 68-239 = callSEContoller 240 = setDeviceString 241 = q_getControllerInfo 242 = q_getSecureElementInfo 243 = q_getBoosterInfo 244 = q_readBoosterRegister 245 = q_sendBoosterCommand 246 = q_triggerAssertion >247 = throw error
These are formatted into a JSON list i.e. { command = 1; }