关于设备唯一标示UUID的问题与数据存储在KeyChain里边_生成唯一id存储到keychain-优快云博客

本文介绍了一个 iOS 应用中用于生成唯一标识符 (UUID) 的方法，并将其安全地存储在 Keychain 中的过程。通过使用 Keychain 来存储 UUID，可以确保即使在应用重启后仍能保持 UUID 的一致性。

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UUID.h 代码如下：

#import <Foundation/Foundation.h>

@interface UUID : NSObject
+(NSString *)getUUID;
@end

UUID.m 代码如下：

#import "UUID.h"
#import "KeyChainStore.h"
#define  KEY_USERNAME_PASSWORD @"com.company.app.usernamepassword"
@implementation UUID
+(NSString *)getUUID
{
    NSString * strUUID = (NSString *)[KeyChainStore load:@"com.company.app.usernamepassword"];
    
   //首次执行该方法时，uuid为空
    if ([strUUID isEqualToString:@""] || !strUUID)
    {
        //生成一个uuid的方法
        CFUUIDRef uuidRef = CFUUIDCreate(kCFAllocatorDefault);
        
        strUUID = (NSString *)CFBridgingRelease(CFUUIDCreateString (kCFAllocatorDefault,uuidRef));
        
        //将该uuid保存到keychain
        [KeyChainStore save:KEY_USERNAME_PASSWORD data:strUUID];
        
    }
    return strUUID;
}
@end

KeyChainStore.h 代码如下

#import <Foundation/Foundation.h>

@interface KeyChainStore : NSObject
+ (void)save:(NSString *)service data:(id)data;
+ (id)load:(NSString *)service;
+ (void)deleteKeyData:(NSString *)service;

@end

KeyChainStore.m 代码如下

//
//  KeyChainStore.m
//  DaBangHui
//
//  Created by DBH on 16/4/15.
//  Copyright © 2016年张梦磊. All rights reserved.
//

#import "KeyChainStore.h"

@implementation KeyChainStore

+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
    return [NSMutableDictionary dictionaryWithObjectsAndKeys:
            (id)kSecClassGenericPassword,(id)kSecClass,
            service, (id)kSecAttrService,
            service, (id)kSecAttrAccount,
            (id)kSecAttrAccessibleAfterFirstUnlock,(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((CFDictionaryRef)keychainQuery);
    //Add new object to search dictionary(Attention:the data format)
    [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(id)kSecValueData];
    //Add item to keychain with the search dictionary
    SecItemAdd((CFDictionaryRef)keychainQuery, NULL);
}

+ (id)load:(NSString *)service {
    id ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    //Configure the search setting
    //Since in our simple case we are expecting only a single attribute to be returned (the password) we can set the attribute kSecReturnData to kCFBooleanTrue
    [keychainQuery setObject:(id)kCFBooleanTrue forKey:(id)kSecReturnData];
    [keychainQuery setObject:(id)kSecMatchLimitOne forKey:(id)kSecMatchLimit];
    CFDataRef keyData = NULL;
    if (SecItemCopyMatching((CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
        @try {
            ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge NSData *)keyData];
        } @catch (NSException *e) {
            NSLog(@"Unarchive of %@ failed: %@", service, e);
        } @finally {
        }
    }
    if (keyData)
        CFRelease(keyData);
    return ret;
}

+ (void)deleteKeyData:(NSString *)service {
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    SecItemDelete((CFDictionaryRef)keychainQuery);
}


@end

直接调用

[UUID getUUID]