iOS 的keyChain

說明:

每一個keyChain的組成如圖,整體是一個字典結構.
1.kSecClass key 定義屬於那一種類型的keyChain
2.不同的類型包含不同的Attributes,這些attributes定義了這個item的具體信息
3.每個item可以包含一個密碼項來存儲對應的密碼

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) {
        // 一個mutable字典結構存儲item信息
        NSMutableDictionary* dic = [NSMutableDictionary dictionary];
        // 確定所屬的類class
        [dic setObject:(id)kSecClassGenericPassword forKey:(id)kSecClass];
        // 設置其他屬性attributes
        [dic setObject:nameField.text forKey:(id)kSecAttrAccount];
        // 添加密碼 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);
}

// 按名稱查找
- (IBAction)sname:(id)sender {
    if (nameField.text.length >0) {
        // 查找條件：1.class 2.attributes 3.search option
        NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:kSecClassGenericPassword,kSecClass, 
                               nameField.text,kSecAttrAccount,
                               kCFBooleanTrue,kSecReturnAttributes,nil];
        CFTypeRef result = nil;
        // 先找到一個item
        OSStatus s = SecItemCopyMatching((CFDictionaryRef)query, &result);
        NSLog(@"select name : %ld",s);  //  errSecItemNotFound 就是找不到
        NSLog(@"%@",result);        
        if (s == noErr) {
            // 繼續查找item的secValue
            NSMutableDictionary* dic = [NSMutableDictionary dictionaryWithDictionary:result];
            // 存儲格式
            [dic setObject:(id)kCFBooleanTrue forKey:kSecReturnData];
            // 確定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) {
        // 先查找看看有沒有
        NSDictionary* query = [NSDictionary dictionaryWithObjectsAndKeys:kSecClassGenericPassword,kSecClass, 
                               nameField.text,kSecAttrAccount,
                               kCFBooleanTrue,kSecReturnAttributes,nil];
        
        CFTypeRef result = nil;
        if (SecItemCopyMatching((CFDictionaryRef)query, &result) == noErr)
        {    
            // 更新后的數據，基礎是搜到的result
            NSMutableDictionary* update = [NSMutableDictionary dictionaryWithDictionary:(NSDictionary*)result];
            // 修改要跟新的項 注意先加后刪的class項
            [update setObject:[query objectForKey:kSecClass] forKey:kSecClass];
            [update setObject:[passwordField.text dataUsingEncoding:NSUTF8StringEncoding] forKey:kSecValueData];
            [update removeObjectForKey:kSecClass];
#if TARGET_IPHONE_SIMULATOR
            // 模擬器的都有個默認的組“test”，刪了，不然會出錯
            [update removeObjectForKey:(id)kSecAttrAccessGroup];
#endif
            // 得到要修改的item，根據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);
   

 

刪除

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

 

注意:

1.區別(標識)一個item要用kSecAttrAccount和kSecAttrService