iOS APP 密碼保存到鑰匙串

      我們在開放APP時，通常要把一些比較重要的用戶信息保留到APP中，我們很多時候的做法是直接裸存到NSUserDefaults。這種做法的很明顯的缺點是不夠安全，以下我們將用代碼封裝一個類，把用戶名賬號密碼等比較重要的信息保存到蘋果自帶的鑰匙串中，這樣除非整個iOS的安全機制被破解，要不然你儲存的東西就會相對的安全，這樣做還有一個好處就是，當用戶刪除該APP，重新下載安裝了，也能讀取到之前保存到鑰匙串里的數據。

直接上代碼：

.h

//
//  KeychainTool.h
//  密碼保存到鑰匙串
//
//  Created by HO on 16/6/9.
//  Copyright © 2016年 HO. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <Security/Security.h>

@interface YFKeychainTool : NSObject

/**
 *  儲存字符串到🔑鑰匙串
 *
 *  @param sValue 對應的Value
 *  @param sKey   對應的Key
 */
+ (void)saveKeychainValue:(NSString *)sValue key:(NSString *)sKey;


/**
 *  從🔑鑰匙串獲取字符串
 *
 *  @param sKey 對應的Key
 *
 *  @return 返回儲存的Value
 */
+ (NSString *)readKeychainValue:(NSString *)sKey;


/**
 *  從🔑鑰匙串刪除字符串
 *
 *  @param sKey 對應的Key
 */
+ (void)deleteKeychainValue:(NSString *)sKey;


@end

 

.m

//
//  KeychainTool.m
//  密碼保存到鑰匙串
//
//  Created by HO on 16/6/9.
//  Copyright © 2016年 HO. All rights reserved.
//

#import "YFKeychainTool.h"

@implementation YFKeychainTool


+ (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)saveKeychainValue:(NSString *)sValue key:(NSString *)sKey{
    NSMutableDictionary * keychainQuery = [self getKeychainQuery:sKey];
    SecItemDelete((__bridge_retained CFDictionaryRef)keychainQuery);

    [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:sValue] forKey:(__bridge_transfer id)kSecValueData];

    SecItemAdd((__bridge_retained CFDictionaryRef)keychainQuery, NULL);
    
}

+ (NSString *)readKeychainValue:(NSString *)sKey
{
    NSString *ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:sKey];
        [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 CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
        @try {
            ret = (NSString *)[NSKeyedUnarchiver unarchiveObjectWithData:(__bridge NSData *)keyData];
        } @catch (NSException *e) {
            NSLog(@"Unarchive of %@ failed: %@", sKey, e);
        } @finally {
        }
    }
    if (keyData)
        CFRelease(keyData);
    return ret;
}
+ (void)deleteKeychainValue:(NSString *)sKey {
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:sKey];
    SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
}

@end

ViewController 調用

//
//  ViewController.m
//  密碼保存到鑰匙串
//
//  Created by HO on 16/6/9.
//  Copyright © 2016年 HO. All rights reserved.
//

#import "ViewController.h"
#import "YFKeychainTool.h"

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UITextField *userName;
@property (weak, nonatomic) IBOutlet UITextField *password;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
}

- (IBAction)saveBtn:(id)sender {
    [YFKeychainTool saveKeychainValue:self.userName.text key:@"userName"];
    [YFKeychainTool saveKeychainValue:self.password.text key:@"password"];
}

- (IBAction)readeBtn:(id)sender {
    
    self.userName.text = [NSString stringWithFormat:@"讀取到用戶名:%@",[YFKeychainTool readKeychainValue:@"userName"]];
    self.password.text = [NSString stringWithFormat:@"讀取到用戶密碼:%@",[YFKeychainTool readKeychainValue:@"password"]];
    
}
- (IBAction)deleteBtn:(id)sender {
    [YFKeychainTool deleteKeychainValue:@"userName"];
    [YFKeychainTool deleteKeychainValue:@"password"];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    
}

@end

 

效果圖: