通常情況下,我們用NSUserDefaults存儲資料資訊,但是對于一些私密資訊,比如密碼、證書等等,就需要使用更為安全的keychain了。keychain裡儲存的資訊不會因App被删除而丢失,在使用者重新安裝App後依然有效,資料還在。
使用蘋果官方釋出的KeychainItemWrapper或者SFHFKeychainUtils很友善,後來看到 iphone使用keychain來存取使用者名和密碼 一文,覺得對了解keychain有很大的幫助,于是ARC控也嘗試了一把。
需要導入Security.framework
@implementation WQKeyChain
+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
return [NSMutableDictionary dictionaryWithObjectsAndKeys:
(__bridge_transfer id)kSecClassGenericPassword,(__bridge_transfer id)kSecClass,
service, (__bridge_transfer id)kSecAttrService,
service, (__bridge_transfer id)kSecAttrAccount,
(__bridge_transfer id)kSecAttrAccessibleAfterFirstUnlock,(__bridge_transfer id)kSecAttrAccessible,
nil];
}
+ ( void)save:(NSString *)service data:(id)data {
// Get search dictionary
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
// Delete old item before add new item
SecItemDelete((__bridge_retained CFDictionaryRef)keychainQuery);
// Add new object to search dictionary(Attention:the data format)
[keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(__bridge_transfer id)kSecValueData];
// Add item to keychain with the search dictionary
SecItemAdd((__bridge_retained CFDictionaryRef)keychainQuery, NULL);
}
+ (id)load:(NSString *)service {
id ret = nil;
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
// Configure the search setting
[keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge_transfer id)kSecReturnData];
[keychainQuery setObject:(__bridge_transfer id)kSecMatchLimitOne forKey:(__bridge_transfer id)kSecMatchLimit];
CFDataRef keyData = NULL;
if (SecItemCopyMatching((__bridge_retained CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
@ try {
ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge_transfer NSData *)keyData];
} @ catch (NSException *e) {
NSLog(@"Unarchive of %@ failed: %@", service, e);
} @ finally {
}
}
return ret;
}
+ ( void)delete:(NSString *)service {
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
SecItemDelete((__bridge_retained CFDictionaryRef)keychainQuery);
}
@end
比如,儲存密碼
@ interface WQUserDataManager : NSObject
+( void)savePassWord:(NSString *)password;
+(id)readPassWord;
+( void)deletePassWord;
@end
#import "WQUserDataManager.h"
@implementation WQUserDataManager
static NSString * const KEY_IN_KEYCHAIN = @"com.wuqian.app.allinfo";
static NSString * const KEY_PASSWORD = @"com.wuqian.app.password";
+(void)savePassWord:(NSString *)password
{
NSMutableDictionary *usernamepasswordKVPairs = [NSMutableDictionary dictionary];
[usernamepasswordKVPairs setObject:password forKey:KEY_PASSWORD];
[WQKeyChain save:KEY_IN_KEYCHAIN data:usernamepasswordKVPairs];
}
+(id)readPassWord
{
NSMutableDictionary *usernamepasswordKVPair = (NSMutableDictionary *)[WQKeyChain load:KEY_IN_KEYCHAIN];
return [usernamepasswordKVPair objectForKey:KEY_PASSWORD];
}
+(void)deletePassWord
{
[WQKeyChain delete:KEY_IN_KEYCHAIN];
}
@end
實作一個簡單的界面,把設定的密碼存起來,然後立即讀取顯示出來看看效果
-(IBAction)btnAciton:(id)sender
{
[WQUserDataManager savePassWord:self.textfield.text];
self.label.text = [WQUserDataManager readPassWord];
}