MFSimpleKeychain Class Reference

#import <MFSimpleKeychain.h>

Inherits NSObject.

Instance Methods
(NSData *)	- publicRSAKeyDataForTag:
(BOOL)	- generateRSAKeyPairWithLength:publicKeyTag:privateKeyTag:
(nullable NSData *)	- dataForRSAKeyWithTag:
(BOOL)	- deleteRSAKeyWithTag:
(SecKeyRef)	- keyRefOfRSAKeyWithTag:
(BOOL)	- hasRSAKeyWithTag:
Initialization
(instancetype)	- init
(instancetype)	- initWithService:
(instancetype)	- initWithService:accessGroup:
Store values
(BOOL)	- setString:forKey:
(BOOL)	- setData:forKey:
(BOOL)	- setString:forKey:promptMessage:
(BOOL)	- setData:forKey:promptMessage:
Remove values
(BOOL)	- deleteEntryForKey:
(void)	- clearAll
Obtain values
(nullable NSString *)	- stringForKey:
(nullable NSData *)	- dataForKey:
(nullable NSString *)	- stringForKey:promptMessage:
(nullable NSData *)	- dataForKey:promptMessage:
(nullable NSData *)	- dataForKey:promptMessage:error:
(BOOL)	- hasValueForKey:

Class Methods
Create helper methods
(MFSimpleKeychain *)	+ keychain
(MFSimpleKeychain *)	+ keychainWithService:
(MFSimpleKeychain *)	+ keychainWithService:accessGroup:

Properties
NSString *	service
NSString *	accessGroup
MFSimpleKeychainItemAccessible	defaultAccessiblity
BOOL	useAccessControl

Detailed Description

A simple helper class to deal with storing and retrieving values from iOS Keychain. It has support for sharing keychain items using Access Group and also for iOS 8 fine grained accesibility over a specific Kyechain Item (Using Access Control). The support is only available for iOS 8+, otherwise it will default using the coarse grained accesibility field. When a NSString or NSData is stored using Access Control and the accesibility flag MFSimpleKeychainItemAccessibleWhenPasscodeSetThisDeviceOnly, iOS will prompt the user for it's passcode or pass a TouchID challenge (if available).

Method Documentation

clearAll()

- (void) clearAll

Remove all entries from the kechain with the service and access group values.

dataForKey:()

- (NSData *) dataForKey:

(NSString *)

key

Fetches a NSData from the keychain

Parameters

key	the key of the value to fetch

Returns

the value or nil if an error occurs.

dataForKey:promptMessage:()

- (nullable NSData *) dataForKey:		(NSString *)	key
promptMessage:		(nullable NSString *)	message

Fetches a NSData from the keychain

Parameters

key	the key of the value to fetch
message	prompt message to display for TouchID/passcode prompt if neccesary

Returns

the value or nil if an error occurs.

dataForKey:promptMessage:error:()

- (nullable NSData *) dataForKey:		(NSString *)	key
promptMessage:		(nullable NSString *)	message
error:		(NSError **)	err

Fetches a NSData from the keychain

Parameters

key	the key of the value to fetch
message	prompt message to display for TouchID/passcode prompt if neccesary
err	Returns an error, if the item cannot be retrieved. F.e. item not found or user authentication failed in TouchId case.

Returns

the value or nil if an error occurs.

dataForRSAKeyWithTag:()

- (NSData *) dataForRSAKeyWithTag:

(NSString *)

keyTag

Returns a RSA key as NSData.

Parameters

keyTag

tag of the key

Returns

the key as NSData or nil if not found

Provided by category MFSimpleKeychain(KeyPair).

deleteEntryForKey:()

- (BOOL) deleteEntryForKey:

(NSString *)

key

Removes an entry from the Keychain using its key

Parameters

key	the key of the entry to delete.

Returns

If the entry was removed it will return YES. Otherwise it will return NO.

deleteRSAKeyWithTag:()

- (BOOL) deleteRSAKeyWithTag:

(NSString *)

keyTag

Removes a key using its tag.

Parameters

keyTag

tag of the key to remove

Returns

if the key was removed successfuly.

Provided by category MFSimpleKeychain(KeyPair).

generateRSAKeyPairWithLength:publicKeyTag:privateKeyTag:()

- (BOOL) generateRSAKeyPairWithLength:		(MFSimpleKeychainRSAKeySize)	keyLength
publicKeyTag:		(NSString *)	publicKeyTag
privateKeyTag:		(NSString *)	privateKeyTag

Generates a RSA key pair with a specific length and tags. Each key is marked as permanent in the Keychain

Parameters

keyLength	number of bits of the keys.
publicKeyTag	tag of the public key
privateKeyTag	tag of the private key

Returns

if the key par is created it will return YES, otherwise NO.

Provided by category MFSimpleKeychain(KeyPair).

hasRSAKeyWithTag:()

- (BOOL) hasRSAKeyWithTag:

(NSString *)

keyTag

Checks if a RSA key exists with a given tag.

Parameters

keyTag

tag of RSA Key

Returns

if the key exists or not.

Provided by category MFSimpleKeychain(KeyPair).

hasValueForKey:()

- (BOOL) hasValueForKey:

(NSString *)

key

Checks if a key has a value in the Keychain

Parameters

key	the key to check if it has a value

Returns

if the key has an associated value in the Keychain or not.

init()

- (instancetype) init

Initialise a MFSimpleKeychain with default values.

Returns

an initialised instance

initWithService:()

- (instancetype) initWithService:

(NSString *)

service

Initialise a MFSimpleKeychain with a given service.

Parameters

service

name of the service to use to save items.

Returns

an initialised instance.

initWithService:accessGroup:()

- (instancetype) initWithService:		(NSString *)	service
accessGroup:		(nullable NSString *)	accessGroup

Initialise a MFSimpleKeychain with a given service and access group.

Parameters

service	name of the service to use to save items.
accessGroup	name of the access group to share items.

Returns

an initialised instance.

keychain()

+ (MFSimpleKeychain *) keychain

Creates a new instance of MFSimpleKeychain

Returns

a new instance

keychainWithService:()

+ (MFSimpleKeychain *) keychainWithService:

(NSString *)

service

Creates a new instance of MFSimpleKeychain with a service name.

Parameters

service

name of the service under all items will be stored.

Returns

a new instance

keychainWithService:accessGroup:()

+ (MFSimpleKeychain *) keychainWithService:		(NSString *)	service
accessGroup:		(NSString *)	accessGroup

Creates a new instance of MFSimpleKeychain with a service name and access group

Parameters

service	name of the service under all items will be stored.
accessGroup	name of the access group to share keychain items.

Returns

a new instance

keyRefOfRSAKeyWithTag:()

- (SecKeyRef) keyRefOfRSAKeyWithTag:

(NSString *)

keyTag

Returns a RSA key as SecKeyRef. You must release it when you're done with it

Parameters

keyTag

tag of the RSA Key

Returns

SecKeyRef of RSA Key

Provided by category MFSimpleKeychain(KeyPair).

publicRSAKeyDataForTag:()

- (NSData *) publicRSAKeyDataForTag:

(NSString *)

keyTag

Returns the public key as NSData.

Parameters

keyTag

tag of the public key

Returns

the public key as NSData or nil if not found

Deprecated:

0.2.0

Provided by category MFSimpleKeychain(Deprecated).

setData:forKey:()

- (BOOL) setData:		(NSData *)	data
forKey:		(NSString *)	key

Saves the NSData with the type kSecClassGenericPassword in the keychain.

Parameters

data	value to save in the keychain
key	key for the keychain entry.

Returns

if the value was saved it will return YES. Otherwise it'll return NO.

setData:forKey:promptMessage:()

- (BOOL) setData:		(NSData *)	data
forKey:		(NSString *)	key
promptMessage:		(nullable NSString *)	message

Saves the NSData with the type kSecClassGenericPassword in the keychain.

Parameters

data	value to save in the keychain
key	key for the keychain entry.
message	prompt message to display for TouchID/passcode prompt if neccesary

Returns

if the value was saved it will return YES. Otherwise it'll return NO.

setString:forKey:()

- (BOOL) setString:		(NSString *)	string
forKey:		(NSString *)	key

Saves the NSString with the type kSecClassGenericPassword in the keychain.

Parameters

string	value to save in the keychain
key	key for the keychain entry.

Returns

if the value was saved it will return YES. Otherwise it'll return NO.

setString:forKey:promptMessage:()

- (BOOL) setString:		(NSString *)	string
forKey:		(NSString *)	key
promptMessage:		(nullable NSString *)	message

Saves the NSString with the type kSecClassGenericPassword in the keychain.

Parameters

string	value to save in the keychain
key	key for the keychain entry.
message	prompt message to display for TouchID/passcode prompt if neccesary

Returns

if the value was saved it will return YES. Otherwise it'll return NO.

stringForKey:()

- (NSString *) stringForKey:

(NSString *)

key

Fetches a NSString from the keychain

Parameters

key	the key of the value to fetch

Returns

the value or nil if an error occurs.

stringForKey:promptMessage:()

- (nullable NSString *) stringForKey:		(NSString *)	key
promptMessage:		(nullable NSString *)	message

Fetches a NSString from the keychain

Parameters

key	the key of the value to fetch
message	prompt message to display for TouchID/passcode prompt if neccesary

Returns

the value or nil if an error occurs.

Property Documentation

accessGroup

- (NSString*) accessGroup

readnonatomicassign

Access Group for Keychain item sharing. If it's nil no keychain sharing is possible. Default value is nil.

defaultAccessiblity

- (MFSimpleKeychainItemAccessible) defaultAccessiblity

readwritenonatomicassign

What type of accessibility the items stored will have. All values are translated to kSecAttrAccessible constants. Default value is MFSimpleKeychainItemAccessibleAfterFirstUnlock.

See also

kSecAttrAccessible

service

- (NSString*) service

readnonatomicassign

Service name under all items are saved. Default value is Bundle Identifier.

useAccessControl

- (BOOL) useAccessControl

readwritenonatomicassign

Tells MFSimpleKeychain to use kSecAttrAccessControl instead of kSecAttrAccessible. It will work only in iOS 8+, defaulting to kSecAttrAccessible on lower version. Default value is NO.

---

The documentation for this class was generated from the following files:

• /Users/atmahajan/MobileAccess-SDK/ios/sdk/MFAuthLib/MFAuthLib/MFSimpleKeychain.h
• /Users/atmahajan/MobileAccess-SDK/ios/sdk/MFAuthLib/MFAuthLib/MFSimpleKeychain.m