iOS开发——keychain的使用

短命女 2022-04-23 11:32 202阅读 0赞

通常情况下，我们用NSUserDefaults存储数据信息，但是对于一些私密信息，比如密码、证书等等，就需要使用更为安全的keychain了。keychain里保存的信息不会因App被删除而丢失，在用户重新安装App后依然有效，数据还在。

使用苹果官方发布的KeychainItemWrapper或者SFHFKeychainUtils很方便，后来看到[ iphone使用keychain来存取用户名和密码][iphone_keychain] 一文，觉得对了解keychain有很大的帮助，于是ARC控也尝试了一把。

需要导入Security.framework

**\[cpp\]** [view plain][] [copy][view plain] [print][view plain] [?][view plain]

1.  @implementation WQKeyChain
2.  \+ (NSMutableDictionary \*)getKeychainQuery:(NSString \*)service \{
3.  return \[NSMutableDictionary dictionaryWithObjectsAndKeys:
4.  (\_\_bridge\_transfer id)kSecClassGenericPassword,(\_\_bridge\_transfer id)kSecClass,
5.  service, (\_\_bridge\_transfer id)kSecAttrService,
6.  service, (\_\_bridge\_transfer id)kSecAttrAccount,
7.  (\_\_bridge\_transfer id)kSecAttrAccessibleAfterFirstUnlock,(\_\_bridge\_transfer id)kSecAttrAccessible,
8.  nil\];
9.  \}
10. 
11. \+ (void)save:(NSString \*)service data:(id)data \{
12. //Get search dictionary
13. NSMutableDictionary \*keychainQuery = \[self getKeychainQuery:service\];
14. //Delete old item before add new item
15. SecItemDelete((\_\_bridge\_retained CFDictionaryRef)keychainQuery);
16. //Add new object to search dictionary(Attention:the data format)
17. \[keychainQuery setObject:\[NSKeyedArchiver archivedDataWithRootObject:data\] forKey:(\_\_bridge\_transfer id)kSecValueData\];
18. //Add item to keychain with the search dictionary
19. SecItemAdd((\_\_bridge\_retained CFDictionaryRef)keychainQuery, NULL);
20. \}
21. 
22. \+ (id)load:(NSString \*)service \{
23. id ret = nil;
24. NSMutableDictionary \*keychainQuery = \[self getKeychainQuery:service\];
25. //Configure the search setting
26. \[keychainQuery setObject:(id)kCFBooleanTrue forKey:(\_\_bridge\_transfer id)kSecReturnData\];
27. \[keychainQuery setObject:(\_\_bridge\_transfer id)kSecMatchLimitOne forKey:(\_\_bridge\_transfer id)kSecMatchLimit\];
28. CFDataRef keyData = NULL;
29. if (SecItemCopyMatching((\_\_bridge\_retained CFDictionaryRef)keychainQuery, (CFTypeRef \*)&keyData) == noErr) \{
30. @try \{
31. ret = \[NSKeyedUnarchiver unarchiveObjectWithData:(\_\_bridge\_transfer NSData \*)keyData\];
32. \} @catch (NSException \*e) \{
33. NSLog(@"Unarchive of %@ failed: %@", service, e);
34. \} @finally \{
35. \}
36. \}
37. return ret;
38. \}
39. 
40. \+ (void)delete:(NSString \*)service \{
41. NSMutableDictionary \*keychainQuery = \[self getKeychainQuery:service\];
42. SecItemDelete((\_\_bridge\_retained CFDictionaryRef)keychainQuery);
43. \}
44. @end

比如，保存密码

**\[cpp\]** [view plain][] [copy][view plain] [print][view plain] [?][view plain]

1.  @interface WQUserDataManager : NSObject
2.  
3.  /\*\*
4.   \* @brief 存储密码
5.   \*
6.   \* @param password 密码内容
7.   \*/
8.  \+(void)savePassWord:(NSString \*)password;
9.  
10. /\*\*
11.  \* @brief 读取密码
12.  \*
13.  \* @return 密码内容
14.  \*/
15. \+(id)readPassWord;
16. 
17. /\*\*
18.  \* @brief 删除密码数据
19.  \*/
20. \+(void)deletePassWord;
21. 
22. @end

**\[cpp\]** [view plain][] [copy][view plain] [print][view plain] [?][view plain]

1.  \#import "WQUserDataManager.h"
2.  
3.  @implementation WQUserDataManager
4.  
5.  static NSString \* const KEY\_IN\_KEYCHAIN = @"com.wuqian.app.allinfo";
6.  static NSString \* const KEY\_PASSWORD = @"com.wuqian.app.password";
7.  
8.  \+(void)savePassWord:(NSString \*)password
9.  \{
10. NSMutableDictionary \*usernamepasswordKVPairs = \[NSMutableDictionary dictionary\];
11. \[usernamepasswordKVPairs setObject:password forKey:KEY\_PASSWORD\];
12. \[WQKeyChain save:KEY\_IN\_KEYCHAIN data:usernamepasswordKVPairs\];
13. \}
14. 
15. \+(id)readPassWord
16. \{
17. NSMutableDictionary \*usernamepasswordKVPair = (NSMutableDictionary \*)\[WQKeyChain load:KEY\_IN\_KEYCHAIN\];
18. return \[usernamepasswordKVPair objectForKey:KEY\_PASSWORD\];
19. \}
20. 
21. \+(void)deletePassWord
22. \{
23. \[WQKeyChain delete:KEY\_IN\_KEYCHAIN\];
24. \}
25. @end

实现一个简单的界面，把设定的密码存起来，然后立即读取显示出来看看效果

**\[cpp\]** [view plain][] [copy][view plain] [print][view plain] [?][view plain]

1.  \-(IBAction)btnAciton:(id)sender
2.  \{
3.  \[WQUserDataManager savePassWord:self.textfield.text\];
4.  self.label.text = \[WQUserDataManager readPassWord\];
5.  \}

![1340590634_6450.png][] ![1340590660_2920.png][]

达到了预期的效果。

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[iphone_keychain]: http://blog.csdn.net/bl1988530/article/details/6887946
[view plain]: http://blog.csdn.net/yiyaaixuexi/article/details/7688745#
[1340590634_6450.png]: https://img-my.csdn.net/uploads/201206/25/1340590634_6450.png
[1340590660_2920.png]: https://img-my.csdn.net/uploads/201206/25/1340590660_2920.png
[https_blog.csdn.net_jiangjunshow]: https://blog.csdn.net/jiangjunshow/article/details/77338485