说明
TouchId指纹识别，FaceId面部解锁，统称为生物识别。
实现
- 引入Local Authentication Framework，如果是iOS 13，默认就有，不用重新引入。
引入头文件import LocalAuthentication - 检查生物识别是否可用
let context = LAContext()
var error: NSError?
if context.canEvaluatePolicy(
LAPolicy.DeviceOwnerAuthenticationWithBiometrics,
error: &error) {
// Biometry is available on the device
} else {
// Biometry is not available on the device
// No hardware support or user has not set up biometric auth
}
上面是验证生物识别是否可用，如果不可用。
错误的原因如下：
- LAError.biometryNotEnrolled - 用户没有注册生物识别信息(没有录入指纹，或者录入面部识别信息).
- LAError.passcodeNotSet - 用户没有设置密码.
- LAError.biometryNotAvailable - 该设备硬件不支持生物识别.
- 如果可用，则可以校验用户信息。
func notifyUser(_ msg: String, err: String?) {
print("msg > \(msg)")
print("err > \(err)")
}
func authorizeBiometrics(_ context: LAContext) {
// Device can use biometric authentication
context.evaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, localizedReason: "Access requires authentication") { (success, error) in
if let err = error {
switch err._code {
case LAError.Code.systemCancel.rawValue:
self.notifyUser("Session cancelled", err: err.localizedDescription)
case LAError.Code.userCancel.rawValue:
self.notifyUser("Please try again", err: err.localizedDescription)
case LAError.Code.userFallback.rawValue:
self.notifyUser("Authentication", err: "Password option selected")
// Custom Code to obtain password here
default:
self.notifyUser("Authentication failed", err: error?.localizedDescription)
}
} else {
// self.notifyUser("Authentication Successful", err: "You now have full access")
if (context.biometryType == LABiometryType.faceID) {
// Device support Face ID
self.notifyUser("Authentication Successful", err: "Device support Face ID")
} else if context.biometryType == LABiometryType.touchID {
// Device supports Touch ID
self.notifyUser("Authentication Successful", err: "Device supports Touch ID")
} else {
// Device has no biometric support
self.notifyUser("Authentication Successful", err: "Device has no biometric support")
}
}
}
}
校验成功则打印信息：
- LABiometryType.faceID 面部识别成功
- LABiometryType.touchID 指纹识别成功
- 其它就是硬件不支持。
检验识别错误，标识为error不为空
- LAError.systemCancel - 授权过程当中被系统取消。特别容易发生在，App推到后台background.
- LAError.userCancel - 授权被用户取消.
- LAError.userFallback - 用户选择用密码，而不是用Touch ID或者Face ID.
代码下载
笔者用SwiftUI实现，下载地址：
https://github.com/zgpeace/iOSBiometrics.git
运行代码
- 如果没有启用Touch ID或者Face ID信息，则打印信息如下。
Biometry is not available on the device
No hardware support to user has not set up biometric auth
msg > User is not enrolled
err > Optional(“No identities are enrolled.”)
- 模拟器也可以开启FaceID 或者 Touch ID。 Simulator > Hardware > Face ID / Touch ID > Enrolled.
- 运行报错信息如下：
Biometry is available on the device
2020-01-13 17:54:00.881269+0800 Biometrics[36054:652894] [access] This app has crashed because it attempted to access privacy-sensitive data without a usage description. The app’s Info.plist must contain an NSFaceIDUsageDescription key with a string value explaining to the user how the app uses this data.
- 需要在target > Info > Custom iOS Target Priorities > 添加Key Value
key :
Privacy - Face ID Usage Description
value:
This app uses Face ID to confirm your identity
5. 第一次打开的时候会弹出确认框
6. 点击OK后就弹出，验证Face ID的界面
7. 点击确认 Simulator > Hardware > Face ID/ Touch ID > Matching Face
8. 控制台打印结果如下：
Biometry is available on the device
msg > Authentication Successful
err > Optional("Device support Face ID")
参考
https://www.techotopia.com/index.php/Implementing_TouchID_Authentication_in_iOS_8_Apps