ios keychain
- 实现了基本功能：添加、查找、删除、更新密码
#import "NYKeychain.h"//引入头文件
[NYKeychain setPassword:password forService:serviceName account:account];//保存／更新密码
NSString *myPassword = [NYKeychain passwordForService:serviceName account:account];//查找密码
[NYKeychain deletePasswordForService:serviceName account:account];//删除密码
- v1.01 实现了基本功能：添加、查找、删除、更新密码