Touch ID

The iPhone 5s comes equipped with Touch ID, a fingerprint scanner. Currently, there is no official developer API for it, because it is intended for unlocking the device and purchasing items on iTunes Store only.

However there is a private API for it; its dylib file is in Xcode 5 in the path

Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk/System/Library/PrivateFrameworks/BiometricKit.framework/BiometricKit

Since it contains a 64-bit ARM segment only, the common disassembly tools cannot process the file.

Inferred Information

Based on a string dump, here is what is implied.

• The codename for it was "mesa"
• It communicates over XPC to a binary that handles access to it
• There's a kernel extension to interface with it
• The kernel extension communicates to the secure keystore to set and verify fingerprints
• The fingerprint scanner calibrates itself and has upgradable firmware
• The fingerprint scanner uses normal image formats (i.e. UIImage) before setting and verifying fingerprints
• There's biometric lockout as well as passcode lockout

String Dump

Below there is a full string dump of the framework, which can hint at its functionalities.

initWithMachServiceName:options:
connectWithReplyBlock:
registerDelegate:withReplyBlock:
suspendWork:withReplyBlock:
enroll:withAuthToken:withReplyBlock:
match:withReplyBlock:
match:withOptions:withReplyBlock:
matchIdentities:withReplyBlock:
cancelWithReplyBlock:
updateIdentity:withReplyBlock:
removeIdentity:withReplyBlock:
getIdentityFromUUID:withReplyBlock:
identities:withReplyBlock:
resetEngineWithReplyBlock:
registerDSID:withAuthToken:withReplyBlock:
registerStoreToken:withReplyBlock:
getCountersignedStoreTokenWithReplyBlock:
getMaxIdentityCount:withReplyBlock:
enrollContinueWithReplyBlock:
pullAlignmentDataWithReplyBlock:
pullMatchTopologyDataWithReplyBlock:
getNodeTopologyForIdentity:withReplyBlock:
preventAutonomousMatchingMode:withReplyBlock:
getProvisioningStateWithReplyBlock:
getCalBlobVersionWithReplyBlock:
getSensorCalibrationStatusWithReplyBlock:
getCalibrationDataStateWithReplyBlock:
setDebugImages:withReplyBlock:
pullCaptureBufferWithReplyBlock:
pullDebugImageData:withReplyBlock:
provisionSensorWithReplyBlock:
unpairSensorWithReplyBlock:
lockSensorWithReplyBlock:
getSerialisedTemplateForIdentity:withReplyBlock:
interfaceWithProtocol:
setRemoteObjectInterface:
remoteObjectInterface
setWithObject:
setClasses:forSelector:argumentIndex:ofReply:
setWithObjects:
enrollResult:
matchResult:
statusMessage:
homeButtonPressed
setExportedInterface:
setExportedObject:
setInterruptionHandler:
resume
invalidate
remoteObjectProxyWithErrorHandler:
code
respondsToSelector:
connect
registerDelegate:
suspendWork:
enroll:withAuthToken:
match:
match:withOptions:
matchIdentities:
cancel
updateIdentity:
removeIdentity:
getIdentityFromUUID:
identities:
getMaxIdentityCount:
resetEngine
enrollContinue
pullAlignmentData
pullMatchTopologyData
getNodeTopologyForIdentity:
preventAutonomousMatchingMode:
getProvisioningState
registerDSID:withAuthToken:
registerStoreToken:
getCountersignedStoreToken:
getCalBlobVersion
getSensorCalibrationStatus
getCalibrationDataState
pullCaptureBuffer
pullDebugImageData:imageWidth:imageHeight:
provisionSensor
unpairSensor
lockSensor
setDebugImages:
getSerialisedTemplateForIdentity:
delegate
setDelegate:
interruptionHandler
_connection
_delegate
_interruptionHandler
setTopology:
setDetails:
topology
details
_topology
_details
initEnrollmentValues
message
messageDetails
objectForKeyedSubscript:
currentPrimaryComponentID
integerValue
doubleValue
statistics
enroll:
enrollResult:componentSet:
enrollProgress:
_fingerOn
_enrolling
_badImagePerFingerDown
_enrollmentStarTime
_touchesPerEnroll
_badImagesPerEnroll
_rejectedImagesPerEnroll
_primaryClusterAdditions
_primaryClusterFailedAdditions
_otherClustersAdditions
_joinEvents
_area
_primaryClusterArea
numberWithBool:
preferencesGetStringValue:
preferencesGetBOOLValue:
enableLogger:toPath:
manager
defaultCenter
appDidEnterBackground:
addObserver:selector:name:object:
appWillEnterForeground:
bundleForClass:
imageNamed:inBundle:
updateEnableLogger
dataWithBytes:length:
startEnrollLog
data
logRemoveIdentity:
bytes
imageFromRawImageData:
imageFromBitmapData:inRect:
pullDebugImageData:target:
getRadarAtachmentsForLastEnrollment
getRadarAtachmentsForLastMatch
length
stringWithString:
getModulationRatio
stringForProvisioningState:
getSensorPatchVersion
stringWithFormat:
getLogsForProcess:
sharedConnection
isFingerprintUnlockAllowed
setGracePeriod:passcode:completionBlock:
finishEnrollLogWithStatus:withIdentity:withTemplate:
matchResult:withDetails:
createMatchInfo:withTopology:withMatchImage:
logMatchResult:withTopology:withImage:withCaptureBuffer:withTemplate:
getBytes:length:
logEnrollMessage:withTopology:withImage:withCaptureBuffer:
logStatus:
enrollProgressMessage:
logRejectedImage:
size
drawInRect:
drawInRect:blendMode:alpha:
CGImage
scale
imageOrientation
imageWithCGImage:scale:orientation:
imageWithImage:inRect:
identityImage:
imageWithImage:withNode:withRect:alpha:
compositeTopologyImage:
imageTopology:forGroup:
imageFauxprint:withTheta:withLamda:
greenColor
imageWithImage:withTintColor:
dataWithData:
imageWithCGImage:
preferencesSetBOOLValue:forKey:
pullDebugImage:
getLoggerAttachmentsForRadar:
stringFromSensorConfiguration
matchIdentity:
topologyImage:
imageWithImage:withMaskImage:
inUse
setInUse:
enrollProgressConfigRenderMode
setEnrollProgressConfigRenderMode:
enrollProgressConfigRenderViewSize
setEnrollProgressConfigRenderViewSize:
renderMode
setRenderMode:
opacity
setOpacity:
_xpcClient
_enrollingMode
_matchingMode
_statistics
_scanbedImage
_fauxprintImage
_nodeRect
_images
_compSet
_rejectTouchCount
_rejectTouch
_showDebugImages
_enableLogger
_enrollImageSet
_isInternalInstall
_inUse
_enrollProgressConfigRenderMode
_renderMode
_opacity
_enrollProgressConfigRenderViewSize
setUuid:
decodeBytesForKey:returnedLength:
initWithUUIDBytes:
decodeIntForKey:
decodeObjectOfClass:forKey:
copy
getUUIDBytes:
encodeBytes:length:forKey:
encodeInt:forKey:
encodeObject:forKey:
biometricKitIdentity
supportsSecureCoding
encodeWithCoder:
initWithCoder:
uuid
type
setType:
attribute
setAttribute:
entity
setEntity:
name
setName:
stringByReplacingOccurrencesOfString:withString:
initWithCapacity:
setLength:
mutableBytes
defaultManager
createDirectoryAtPath:withIntermediateDirectories:attributes:error:
removeItemAtPath:error:
UUIDString
setMessageDetails:
setCaptureImage:
setRenderedImage:
progress
setProgress:
setCurrentPrimaryComponentID:
captureImage
renderedImage
setMessage:
_message
_progress
_currentPrimaryComponentID
_captureImage
_renderedImage
_messageDetails
setX:
setY:
angle
setAngle:
_angle
setTransformationCoordinates:
componentID
setComponentID:
transformationCoordinates
_componentID
_transformationCoordinates
pathComponents
com.apple.biometrickitd
T@"<BiometricKitDelegate>",N,V_delegate
interruptionHandler
T@?,C,N,V_interruptionHandler
topology
T@"NSDictionary",&,N,V_details
com.apple.fingerprint.enroll.attempts
com.apple.fingerprint.enroll.passes
com.apple.fingerprint.enroll.touchesPerEnroll
com.apple.fingerprint.enroll.badImagesPerEnroll
com.apple.fingerprint.enroll.rejectedImagesPerEnroll
com.apple.fingerprint.enroll.primaryClusterAdditions
com.apple.fingerprint.enroll.primaryClusterFailedAdditions
com.apple.fingerprint.enroll.otherClustersAdditions
com.apple.fingerprint.enroll.joinEvents
com.apple.fingerprint.enroll.clusterCount
com.apple.fingerprint.enroll.nodeCount
com.apple.fingerprint.enroll.primaryClusterNodeCount
com.apple.fingerprint.enroll.area
com.apple.fingerprint.enroll.primaryClusterArea
com.apple.fingerprint.enroll.passTime
com.apple.fingerprint.enroll.fails
com.apple.fingerprint.enroll.failTime
com.apple.ManagedConfiguration.profileListChanged
com.apple.biometrickitd.debugLogEnabled
com.apple.biometrickitd.debugLogPath
debugLogEnabled
debugLogPath
BKOptionSuppressHapticFeedback
BKOptionFilterOutHomeButtonEvents
BKOptionMatchForUnlock
InternalBuild
scanbed
synthetic
Uninitialized
Not Provisioned
Unprovisioned
Provisioned
Provisioned Locked
Unpaired
Unknown
biosensor,mesa
modulation-ratio
AppleBiometricSensor
patch-version
Mesa configuration:
Provisioning Status: %@
Calibrated: 
- Version: 
- Signed: 
Modulation ratio: 
Kernel: 
Thick kernel
Thin kernel
Sensor Patch Version: 
Steps to Reproduce:
inUse
TB,V_inUse
enrollProgressConfigRenderMode
Ti,N,V_enrollProgressConfigRenderMode
enrollProgressConfigRenderViewSize
T{CGSize=dd},N,V_enrollProgressConfigRenderViewSize
renderMode
Ti,N,V_renderMode
opacity
Tf,N,V_opacity
Notification callback.
BiometricKitErrorDomain
BKIdentityUUID
BKIdentityType
BKIdentityAttribute
BKIdentityEntityNumber
BKIdentityName
/var/mobile/BiometricKit/biometrickitd
BKEPDReason
BKEPDNewNodeID
BKEPDNewComponentID
BKEPDNewNodeCoordinates
BKEPDRemovedNodeID
BKEPDRemovedComponentID
BKEPDExtendedComponentID
BKEPDResultComponentID
BKEPDMergedInComponents
BKEPDRedundantNode
BKTDLargestCompArea
BKTDLargestCompNodes
BKTDTotalArea
BKTDTotalNodes
BKTemplateUpdated
Td,N,V_x
Td,N,V_y
angle
Td,N,V_angle
componentID
Tq,N,V_componentID
transformationCoordinates
T@"BiometricKitEnrollProgressCoordinates",&,N,V_transformationCoordinates
Remove identity: %@
Log package:%@
biometrickitd
%@.tar.gz
cd %@ && tar -cjf %@ %@
Time: % 8.3f
PASS
FAIL
Closing log with result %@
Template identity:
UUID  : %@
Type  : %i
Attrib: %i
Entity: %i
Error: Unable to get identity
Serialised template: %@
%@_%04d.bin
Status message: %@
Progress %i
Count of enrollments: %i
BiometricKitErrorTaskCancelled
BiometricKitErrorIdentityInvalid
BiometricKitErrorIdentityNotAllowed
BiometricKitErrorIdentityErrorInvalidData
BiometricKitErrorIdentityErrorUnknown
BiometricKitStatusFingerOn
BiometricKitStatusFingerOff
BiometricKitStatusEnrollmentComplete
BiometricKitStatusEnrollmentCancelled
BiometricKitStatusEnrollmentFailed
BiometricKitStatusEnrollmentTimeout
BiometricKitStatusUnknownError
BiometricKitStatusImageRejected
BiometricKitStatusNoCalibration
BiometricKitImageForProcessing
BiometricKitStatusTemplateListUpdated
BiometricKitStatusRequestFingerOff
BiometricKitStatusAutoMatchingStarted
BiometricKitStatusAutoMatchingStopped
BiometricKitStatusCaptureRestart
BiometricKitStatusScanTooShort
BiometricKitStatusAutoMatchingStartByHomeButton
BiometricKitStatusMatchingCancelled
BiometricKitStatusFingerOnBeforeFirstPasscodeUnlock
BiometricKitStatusFingerOnInPasscodeLockout
BiometricKitStatusFingerOnInBioLockout
BiometricKitStatusFingerOnTokenExpired
BiometricKitStatusESDRecovery
BiometricKitStatusImageRejectedUnknown
BiometricKitStatusImageRejectedBadBlocks
BiometricKitStatusImageRejectedChFPN
BiometricKitStatusImageRejectedCaFPN
BiometricKitStatusSensorOperationModeIdle
BiometricKitStatusSensorOperationModeCapture
BiometricKitStatusSensorOperationModePause
Other unknown status %i
Image #%i was rejected
Sensor patch version: %ld
Sensor patch version: unknown
Calibration Data: %@
Capture buffer: %@
Matcher: image refused
Matcher: image %s node %u
added as
replaced
Coordinates: %s[%i, %i, %i]
inverse of 
Parent: %i
Processed image: %@
Enroll debug log, version 7
static const node_placement_t table_%02i = 
%@{%i,%i,%i,%i,%i,%i,{
%@{%i,%i,%i,%i,%i}
%@},%i,%i,%i,%i,%i,0x%04x};
bin8
bin16
binXX
calibdata.bin
calibration-blob
Image #%i%s
 was sent to matcher
Match result
Match details:
Matching score: %i
Match S2S count: %i
Matching node: %i
Updated node: %i
Not available
No match (artificial)
No match
Image #%i
Warning: the log is not complete, previous part of the log was deleted.
Starting enrollment
Starting matching
No known identities with enroll log are available.
Known identities with enroll log available:
%@ : %@
Match debug log, version 7
messages.log
OS version: %@ (%@)
Mesa: %@
Process name:%@
PrimaryUsagePage
PrimaryUsage
com.apple.iokit.hid.displayStatus
com.apple.mobile.keybagd.lock_status
AppleMesaSEPDriver
IOGeneralInterest
ScanningState
ScanningStateIdle
ScanningStateShortScanning
ScanningStateLongScanning
Unknown scanning state %i
Event: %@
HomeButtonPress
ExtendedDeviceLockState
MobileKeyBagDeviceIsUnlocked
MobileKeyBagDeviceIsLocked
MobileKeyBagDeviceIsLocking
MobileKeyBagDisabled
MobileKeyBagDeviceUnlockInProgress
MobileKeyBagDeviceInGracePeriod
MobileKeyBagDeviceInAssertDelay
MobileKeyBagDeviceInBioUnlock
Unknown lock state %i
DisplayOn
DisplayOff
/SourceCache/Mesa/Mesa-152/AppleBiometricServices/BiometricKit/BiometricKitDebugLog.m
/var/mobile/Library/Logs/CrashReporter/BiometricKit
v24@0:8@"BiometricKitIdentity"16
@"NSXPCConnection"
@"<BiometricKitDelegate>"
@"BiometricKitXPCClient"
@"BiometricKitStatistics"
@"UIImage"
[25{CGRect="origin"{CGPoint="x"d"y"d}"size"{CGSize="width"d"height"d}}]
[25@"UIImage"]
{?="count"i"capa"i"items"^^{?}"unusedImageCount"i"componentCount"i"componentCapa"i"bestComponentIndex"i"bestMapiComponentIndex"i"components"^^{?}"mapiNodeAddedIndex"s"mapiNodeRemovedIndex"s"updateCount"i"structureIsInconsistent"B}
{?="nodes"[25{?="imageData"@"NSData""width"I"height"I}]}
BiometricKitXpcProtocol
BiometricKitDelegateXpcProtocol
BiometricKitXPCClient
BiometricKitTemplateInfo
BiometricKitStatistics
BiometricKit
BiometricKitDelegate
BiometricKitIdentity
NSSecureCoding
NSCoding
BiometricKitMatchInfo
BiometricKitEnrollProgressInfo
BiometricKitEnrollProgressCoordinates
BiometricKitEnrollProgressMergedComponent
BiometricKitDebugLog

This hardware article is a "stub", an incomplete page. Please add more content to this article and remove this tag.