KeyChainWrapper

1 keyChainWrapper是MRC代码，要禁用ARC -fno-objc-arc

2 要导入Security.framework框架

3 获得一个不变的UUID

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // 判断Keychain中是否存在这条Item如果不存在SecItem就添加。
    NSDictionary *query = [NSDictionary dictionaryWithObjectsAndKeys:
                           (__bridge NSString *)kSecClassGenericPassword, kSecClass,
                           @"bundleSeedID", kSecAttrAccount,
                           @"", kSecAttrService,
　　　　　　　　　　　　　　　　　　//设置为True可以配合SecItemCopyMatching属性获得SecItem的信息。有的话
                           (id)kCFBooleanTrue, kSecReturnAttributes,
                           nil];
    CFDictionaryRef result = nil;
    OSStatus status = SecItemCopyMatching((CFDictionaryRef)query, (CFTypeRef *)&result);
    if (status == errSecItemNotFound)
        status = SecItemAdd((CFDictionaryRef)query, (CFTypeRef *)&result);
    if (status != errSecSuccess)
        return nil;
    // 获取AccessGroup即 AppIdentifierPrefix 和 Bundle Id的组合。
    NSString *accessGroup = [(__bridge NSDictionary *)result objectForKey:(__bridge NSString *)kSecAttrAccessGroup];
    // 初始化（根据标识符获取）一个wrapper
    KeychainItemWrapper *wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"jifeifei" accessGroup:accessGroup];
    // account 不存在是初始化出来的，设置 kSecAttrAccount 的 value
    NSString *account = [wrapper objectForKey:(id)kSecAttrAccount];
    if (!account || account.length == 0) {
        [wrapper setObject:@"jifeifei" forKey:(id)kSecAttrAccount];
    }
    // uuid 不存在是初始化出来的 设置 kSecValueData 的 Value
    NSString *uuid = [wrapper objectForKey:(id)kSecValueData];
    if (!uuid || uuid.length == 0) {
        uuid = [[[UIDevice currentDevice].identifierForVendor.UUIDString stringByReplacingOccurrencesOfString:@"-" withString:@""] lowercaseString];
        [wrapper setObject:uuid forKey:(id)kSecValueData];
    }
    
    [self attempt];
    
    return YES;
}

4 获得IDFA方法 如果打开限制广告追踪标识符会出现取不到IDFA的情况

 #import <AdSupport/AdSupport.h>

  NSString *adId = [[[ASIdentifierManager sharedManager] advertisingIdentifier] UUIDString];

5 直接使用KeyChain保存数据

  使用keyChain保存数据的三个方法：

    // 添加保存的数据    
    SecItemAdd(CFDictionaryRef  _Nonnull attributes, <#CFTypeRef  _Nullable * _Nullable result#>)
    // 删除保存的数据    
    SecItemDelete(<#CFDictionaryRef  _Nonnull query#>)
    // 更新保存的数据    
    SecItemUpdate(CFDictionaryRef  _Nonnull query, <#CFDictionaryRef  _Nonnull attributesToUpdate#>)
    // 获取保存的数据
    SecItemCopyMatching(<#CFDictionaryRef  _Nonnull query#>, <#CFTypeRef  _Nullable * _Nullable result#>)

#import <Foundation/Foundation.h>

@interface FFKeyChain : NSObject
+ (void)save:(NSString *)serve data:(id)Data;
+ (id)read:(NSString *)serve;
@end



#import "FFKeyChain.h"

@implementation FFKeyChain
/*
 
 https://blog.csdn.net/zhoushuangjian511/article/details/78583429
 
 https://www.cnblogs.com/whyandinside/p/3303108.html
 kSecAttrAccessible: 属性控制keychain中的Item什么时候可以被访问。可选值有 kSecAttrAccessibleWhenUnlocked, kSecAttrAccessibleAfterFirstUnlock, kSecAttrAccessibleAlways, kSecAttrAcessibleWhenUnlockedThisDeviceOnly, kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly, kSecAttrAccessibleAlwaysThisDeviceOnly
 带有ThisDeviceOnly的意思是如果手机使用其他device的备份restore了之后这些Item就不存在了。
 
 kSecAttrAccessGroup: 如果希望，keychain的item可以被多个应用share， 可以给Item设置这个属性， 类型是CFStringRef, 应用程序在被编译时，可以在entitlement中指定自己的accessgroup，如果应用中的accessgroup和keyChain item中的Accessgroup名字一直，那么这个应用就可以访问这个item，缺点是：accessgroup是由开发者指定的，他可以故意跟其他应用的accessgroup一样，已达到访问其他应用item的目的。同事还支持 wild card ,如keychain-dumper将自己的accessgroup指定为*，从而可以把keychain中所有的Item都dump出来。
 
 kSecAttrAccount 必须 指定一个字典键，其值为物品的描述属性， 使用此键设置或获得，CFStringRef， 包含账户名
 kSecAttrService 必须 指定一个字典键，其值为物品的描述属性， 使用此键设置或获得，CFStringRef与该项目相关的服务

 */

+ (NSMutableDictionary *)getKeyChainQuery:(NSString *)serve {
    return [@{(id)kSecClass:(id)kSecClassGenericPassword,
             (id)kSecAttrAccount:serve,
             (id)kSecAttrService:serve,
             (__bridge NSString *)kSecAttrAccessible:(__bridge NSString *)kSecAttrAccessibleAfterFirstUnlock,
               } mutableCopy];
}

+(NSMutableDictionary*)keyChainIdentifier:(NSString*)identifier {
    NSMutableDictionary * keyChainMutableDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:(id)kSecClassGenericPassword,kSecClass,identifier,kSecAttrService,identifier,kSecAttrAccount,kSecAttrAccessibleAfterFirstUnlock,kSecAttrAccessible, nil];
    return keyChainMutableDictionary;
}


+ (void)save:(NSString *)serve data:(id)Data {
    NSMutableDictionary *mDic = [self keyChainIdentifier:serve];//[self getKeyChainQuery:serve];//;
    SecItemDelete((CFDictionaryRef)mDic);
    [mDic setObject:[NSKeyedArchiver archivedDataWithRootObject:Data] forKey:(id)kSecValueData];
    OSStatus sta = SecItemAdd((__bridge CFDictionaryRef)mDic, NULL);
    if (sta == noErr) {
        NSLog(@"成功。。");
    };
}

+ (void)delete:(NSString *)serve {
    NSMutableDictionary *mdic = [self getKeyChainQuery:serve];
    SecItemDelete((__bridge CFDictionaryRef)mdic);
}

+ (void)neeUpdateServe:(NSString *)server updateValue:(NSString *)value {
    NSMutableDictionary *mdic = [self getKeyChainQuery:server];
    OSStatus status = SecItemUpdate((__bridge CFDictionaryRef)mdic, (__bridge CFDictionaryRef)@{(id)kSecValueData:[NSKeyedArchiver archivedDataWithRootObject:value]});
    if (status == errSecSuccess) {
        NSLog(@"更新成功");
    }else {
        NSLog(@"更新失败");
    }
}

+ (id)read:(NSString *)serve {
    id let = nil;
    NSMutableDictionary *mdic = [self getKeyChainQuery:serve];
    [mdic setValue:(id)kCFBooleanTrue forKey:(id)kSecReturnData];
    [mdic setValue:(id)kSecMatchLimitOne forKey:(id)kSecMatchLimit];
    CFDataRef keyData = nil;
    if (SecItemCopyMatching((__bridge CFDictionaryRef)mdic, (CFTypeRef *)&keyData) == noErr) {
        @try{
            let = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge NSData *)keyData];
        } @catch (NSException *e) {
            NSLog(@"Unarchiver of %@ failed %@", serve, e);
        } @finally {
            
        }
    }
    if (keyData) {
        CFRelease(keyData);
    }
    return let;

}
@end