iOS 的keyChain

http://www.cnblogs.com/v2m_/archive/2012/01/18/2325782.html

说明:

每一个keyChain的组成如图,整体是一个字典结构.
1.kSecClass key 定义属于那一种类型的keyChain
2.不同的类型包含不同的Attributes,这些attributes定义了这个item的具体信息
3.每个item可以包含一个密码项来存储对应的密码

使用:
引入Security包，引入文件 #import <Security/Security.h>

添加

- (IBAction)add:(id)sender {    if (nameField.text.length > 0 && passwordField.text.length > 0) {        // 一个mutable字典结构存储item信息        NSMutableDictionary* dic = [NSMutableDictionary dictionary];        // 确定所属的类class        [dic setObject:(id)kSecClassGenericPassword forKey:(id)kSecClass];        // 设置其他属性attributes        [dic setObject:nameField.text forKey:(id)kSecAttrAccount];        // 添加密码 secValue  注意是object 是 NSData        [dic setObject:[passwordField.text dataUsingEncoding:NSUTF8StringEncoding] forKey:(id)kSecValueData];        // SecItemAdd        OSStatus s = SecItemAdd((CFDictionaryRef)dic, NULL);        NSLog(@"add : %ld",s);    }}

查找

// 查找全部- (IBAction)sel:(id)sender {    NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:kSecClassGenericPassword,kSecClass,                            kSecMatchLimitAll,kSecMatchLimit,                           kCFBooleanTrue,kSecReturnAttributes,nil];    CFTypeRef result = nil;    OSStatus s = SecItemCopyMatching((CFDictionaryRef)query, &result);    NSLog(@"se;ect all : %ld",s);    NSLog(@"%@",result);}// 按名称查找- (IBAction)sname:(id)sender {    if (nameField.text.length >0) {        // 查找条件：1.class 2.attributes 3.search option        NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:kSecClassGenericPassword,kSecClass,                                nameField.text,kSecAttrAccount,                               kCFBooleanTrue,kSecReturnAttributes,nil];        CFTypeRef result = nil;        // 先找到一个item        OSStatus s = SecItemCopyMatching((CFDictionaryRef)query, &result);        NSLog(@"select name : %ld",s);  //  errSecItemNotFound 就是找不到        NSLog(@"%@",result);                if (s == noErr) {            // 继续查找item的secValue            NSMutableDictionary* dic = [NSMutableDictionary dictionaryWithDictionary:result];            // 存储格式            [dic setObject:(id)kCFBooleanTrue forKey:kSecReturnData];            // 确定class            [dic setObject:[query objectForKey:kSecClass] forKey:kSecClass];            NSData* data = nil;            // 查找secValue            if (SecItemCopyMatching((CFDictionaryRef)dic, (CFTypeRef*)&data) == noErr) {                if (data.length)                    NSLog(@"%@",[[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease]);            }        }    }}

修改

- (IBAction)update:(id)sender {    if (nameField.text.length >0 && passwordField.text.length > 0) {        // 先查找看看有没有        NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:kSecClassGenericPassword,kSecClass,                                nameField.text,kSecAttrAccount,                               kCFBooleanTrue,kSecReturnAttributes,nil];                CFTypeRef result = nil;        if (SecItemCopyMatching((CFDictionaryRef)query, &result) == noErr)        {                // 更新后的数据，基础是搜到的result            NSMutableDictionary* update = [NSMutableDictionary dictionaryWithDictionary:(NSDictionary*)result];            // 修改要跟新的项 注意先加后删的class项            [update setObject:[query objectForKey:kSecClass] forKey:kSecClass];            [update setObject:[passwordField.text dataUsingEncoding:NSUTF8StringEncoding] forKey:kSecValueData];            [update removeObjectForKey:kSecClass];#if TARGET_IPHONE_SIMULATOR            // 模拟器的都有个默认的组“test”，删了，不然会出错            [update removeObjectForKey:(id)kSecAttrAccessGroup];#endif            // 得到要修改的item，根据result，但要添加class            NSMutableDictionary* updateItem = [NSMutableDictionary dictionaryWithDictionary:result];            [updateItem setObject:[query objectForKey:(id)kSecClass] forKey:(id)kSecClass];            // SecItemUpdate            OSStatus status = SecItemUpdate((CFDictionaryRef)updateItem, (CFDictionaryRef)update);            NSLog(@"update:%ld",status);   

 

删除

- (IBAction)del:(id)sender {    if (nameField.text.length >0) {        // 删除的条件        NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:kSecClassGenericPassword,kSecClass,                                nameField.text,kSecAttrAccount,nil];        // SecItemDelete        OSStatus status = SecItemDelete((CFDictionaryRef)query);        NSLog(@"delete:%ld",status);    // //  errSecItemNotFound 就是没有    }}

 

注意:

1.区别(标识)一个item要用kSecAttrAccount和kSecAttrService