IOS KeyChain理解及代码事例

来源：互联网发布：守望先锋亚服淘宝编辑：程序博客网时间：2024/04/30 06:21
对KeyChain的理解，可参照http://my.oschina.net/w11h22j33/blog/206713
文中利用KeyChain保存用户名和密码，用户名放在属性中，密码放在密码项中；其中对KeyChain项的增删改查，我个人觉得是有问题的，为了方面自己代码上的使用，也帮助阅读该文的其他读者更好的理解，我修正了代码如下：
</pre><p></p><p><pre name="code" class="objc">//存储/增加-(IBAction)saveClicked:(id)sender{        if(_nameTF.text.length > 0 && _psdTF.text.length > 0) {        NSMutableDictionary* dic = [NSMutableDictionary dictionary];                [dic setObject:(__bridge_transfer id)kSecClassGenericPassword forKey:(__bridge_transfer id)kSecClass];        [dic setObject:_nameTF.text forKey:(__bridge_transfer id)kSecAttrAccount];        [dic setObject:[_psdTF.text dataUsingEncoding:NSUTF8StringEncoding] forKey:(__bridge_transfer id)kSecValueData];                OSStatus s = SecItemAdd((__bridge_retained CFDictionaryRef)dic, NULL);        NSLog(@"%d",s);    }}//获取/查询-(IBAction)showClicked:(id)sender{    if(_nameTF.text.length > 0) {        NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:                               (__bridge_transfer id)kSecClassGenericPassword, (__bridge_transfer id)kSecClass,                               _nameTF.text, (__bridge_transfer id)kSecAttrAccount,                               kCFBooleanTrue, kSecReturnAttributes,nil];                CFTypeRef result = nil;        OSStatus s = SecItemCopyMatching((__bridge_retained CFDictionaryRef)query, &result);                NSLog(@"%d",s);        NSLog(@"%@",result);                if(s == noErr) {//通过用户名判断item项是否存在            NSMutableDictionary* dic = [NSMutableDictionary dictionary];            [dic setObject:_nameTF.text forKey: (__bridge_transfer id)kSecAttrAccount];            [dic setObject:(__bridge_transfer id)kCFBooleanTrue forKey:(__bridge_transfer id)kSecReturnData];            [dic setObject:(__bridge_transfer id)kSecClassGenericPassword forKey:(__bridge_transfer id)kSecClass];                        CFDataRef dataRef = NULL;            if(SecItemCopyMatching((__bridge_retained CFDictionaryRef)dic, (CFTypeRef*)&dataRef) == noErr) {                                NSData *data = (__bridge_transfer id)dataRef;                NSLog(@"%ld", data.length);                                NSLog(@"%@",[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);            }        }    }else{                NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:                               (__bridge_transfer id)kSecClassGenericPassword,(__bridge_transfer id)kSecClass,                               (__bridge_transfer id)kSecMatchLimitAll, (__bridge_transfer id)kSecMatchLimit,                               (__bridge_transfer id)kCFBooleanTrue,(__bridge_transfer id)kSecReturnAttributes,nil];                CFArrayRef result = NULL;        OSStatus s = SecItemCopyMatching((__bridge_retained CFDictionaryRef)query, (CFTypeRef*)&result);                NSArray *array = (__bridge_transfer NSArray*)result;//(可以遍历所有keychain项)                NSLog(@"%d",s);        NSLog(@"%@",result);    }        }//删除-(IBAction)delClicked:(id)sender{        if(_nameTF.text.length > 0){        NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:(__bridge_transfer id)kSecClassGenericPassword,kSecClass,                               _nameTF.text,kSecAttrAccount,nil];        OSStatus status = SecItemDelete((__bridge_retained CFDictionaryRef)query);        NSLog(@"%d",status);    }}//改-(IBAction)modifyClicked:(id)sender{        if(_nameTF.text.length > 0 && _psdTF.text.length > 0) {        NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:                               (__bridge_transfer id)kSecClassGenericPassword, (__bridge_transfer id)kSecClass,                               _nameTF.text, (__bridge_transfer id)kSecAttrAccount,                               (__bridge_transfer id)kCFBooleanTrue, (__bridge_transfer id)kSecReturnAttributes,nil];                CFTypeRef result = nil;        if(SecItemCopyMatching((__bridge_retained CFDictionaryRef)query, &result) == noErr)//存在才修改        {            //设置需要更新的属性列表，一定要删除kSecClass，因为不能update不该字段，否则会报错            NSMutableDictionary* update = [[NSMutableDictionary alloc]init];            [update setObject:[_psdTF.text dataUsingEncoding:NSUTF8StringEncoding] forKey:(__bridge_transfer id)kSecValueData];            [update removeObjectForKey:(__bridge_transfer id)kSecClass];                        //设置查找条件，即根据这个条件找到keychain项            NSMutableDictionary* updateItem = [[NSMutableDictionary alloc]init];            [updateItem setObject:[query objectForKey:(__bridge_transfer id)kSecClass] forKey:(__bridge_transfer id)kSecClass];            [updateItem setObject:_nameTF.text forKey:(__bridge_transfer id)kSecAttrAccount];                        //参数一表示要查虚的，参数二表示更新后的值            OSStatus status = SecItemUpdate((__bridge_retained CFDictionaryRef)updateItem, (__bridge_retained CFDictionaryRef)update);            NSLog(@"%d",status);        }    }}
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