标签：ios 计算机 objective-c 存储 数据
UUID一般只生成一次，保存在iOS系统里面，如果应用删除了，重装应用之后它的UUID还是一样的，除非系统重置 。但是不能保证在以后的系统升级后还能用（如果系统保存了该信息就能用）.
由于IOS系统存储的数据都是在sandBox里面，一旦删除App，sandBox也不复存在。好在有一个例外，那就是keychain（钥匙串）。
通常情况下，IOS系统用NSUserDefaults存储数据信息，但是对于一些私密信息，比如密码、证书等等，就需要使用更为安全的keychain了。
iOS的keychain服务提供了一种安全的保存私密信息（密码，序列号，证书等）的方式，每个ios程序都有一个独立的keychain存储。相对于NSUserDefaults、文件保存等一般方式，keychain保存更为安全，而且keychain里保存的信息不会因App被删除而丢失，所以在重装App后，keychain里的数据还能使用。从ios 3。0开始，跨程序分享keychain变得可行。
如何需要在应用里使用使用keyChain，我们需要导入Security.framework ，keychain的操作接口声明在头文件SecItem.h里。直接使用SecItem.h里方法操作keychain，需要写的代码较为复杂，为减轻咱们程序员的开发，我们可以使用一些已经封装好了的工具类，下面我会简单介绍下我用过的两个工具类：KeychainItemWrapper和SFHFKeychainUtils。
/*
File: KeychainItemWrapper.h
Abstract:
Objective-C wrapper for accessing a single keychain item.
Version: 1.2
Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple
Inc. ("Apple") in consideration of your agreement to the following
terms, and your use, installation, modification or redistribution of
this Apple software constitutes acceptance of these terms. If you do
not agree with these terms, please do not use, install, modify or
redistribute this Apple software.
In consideration of your agreement to abide by the following terms, and
subject to these terms, Apple grants you a personal, non-exclusive
license, under Apple‘s copyrights in this original Apple software (the
"Apple Software"), to use, reproduce, modify and redistribute the Apple
Software, with or without modifications, in source and/or binary forms;
provided that if you redistribute the Apple Software in its entirety and
without modifications, you must retain this notice and the following
text and disclaimers in all such redistributions of the Apple Software.
Neither the name, trademarks, service marks or logos of Apple Inc. may
be used to endorse or promote products derived from the Apple Software
without specific prior written permission from Apple. Except as
expressly stated in this notice, no other rights or licenses, express or
implied, are granted by Apple herein, including but not limited to any
patent rights that may be infringed by your derivative works or by other
works in which the Apple Software may be incorporated.
The Apple Software is provided by Apple on an "AS IS" basis. APPLE
MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,
MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED
AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),
STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
Copyright (C) 2010 Apple Inc. All Rights Reserved.
*/
#import <UIKit/UIKit.h>
/*
The KeychainItemWrapper class is an abstraction layer for the iPhone Keychain communication. It is merely a
simple wrapper to provide a distinct barrier between all the idiosyncracies involved with the Keychain
CF/NS container objects.
*/
@interface KeychainItemWrapper : NSObject
{
NSMutableDictionary *keychainItemData; // The actual keychain item data backing store.
NSMutableDictionary *genericPasswordQuery; // A placeholder for the generic keychain item query used to locate the item.
}
@property (nonatomic, retain) NSMutableDictionary *keychainItemData;
@property (nonatomic, retain) NSMutableDictionary *genericPasswordQuery;
// Designated initializer.
- (id)initWithIdentifier: (NSString *)identifier accessGroup:(NSString *) accessGroup;
- (void)setObject:(id)inObject forKey:(id)key;
- (id)objectForKey:(id)key;
// Initializes and resets the default generic keychain item data.
- (void)resetKeychainItem;
@end
/*
File: KeychainItemWrapper.m
Abstract:
Objective-C wrapper for accessing a single keychain item.
Version: 1.2
Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple
Inc. ("Apple") in consideration of your agreement to the following
terms, and your use, installation, modification or redistribution of
this Apple software constitutes acceptance of these terms. If you do
not agree with these terms, please do not use, install, modify or
redistribute this Apple software.
In consideration of your agreement to abide by the following terms, and
subject to these terms, Apple grants you a personal, non-exclusive
license, under Apple‘s copyrights in this original Apple software (the
"Apple Software"), to use, reproduce, modify and redistribute the Apple
Software, with or without modifications, in source and/or binary forms;
provided that if you redistribute the Apple Software in its entirety and
without modifications, you must retain this notice and the following
text and disclaimers in all such redistributions of the Apple Software.
Neither the name, trademarks, service marks or logos of Apple Inc. may
be used to endorse or promote products derived from the Apple Software
without specific prior written permission from Apple. Except as
expressly stated in this notice, no other rights or licenses, express or
implied, are granted by Apple herein, including but not limited to any
patent rights that may be infringed by your derivative works or by other
works in which the Apple Software may be incorporated.
The Apple Software is provided by Apple on an "AS IS" basis. APPLE
MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,
MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED
AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),
STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
Copyright (C) 2010 Apple Inc. All Rights Reserved.
*/
#import "KeychainItemWrapper.h"
#import <Security/Security.h>
/*
These are the default constants and their respective types,
available for the kSecClassGenericPassword Keychain Item class:
kSecAttrAccessGroup - CFStringRef
kSecAttrCreationDate - CFDateRef
kSecAttrModificationDate - CFDateRef
kSecAttrDescription - CFStringRef
kSecAttrComment - CFStringRef
kSecAttrCreator - CFNumberRef
kSecAttrType - CFNumberRef
kSecAttrLabel - CFStringRef
kSecAttrIsInvisible - CFBooleanRef
kSecAttrIsNegative - CFBooleanRef
kSecAttrAccount - CFStringRef
kSecAttrService - CFStringRef
kSecAttrGeneric - CFDataRef
See the header file Security/SecItem.h for more details.
*/
@interface KeychainItemWrapper (PrivateMethods)
/*
The decision behind the following two methods (secItemFormatToDictionary and dictionaryToSecItemFormat) was
to encapsulate the transition between what the detail view controller was expecting (NSString *) and what the
Keychain API expects as a validly constructed container class.
*/
- (NSMutableDictionary *)secItemFormatToDictionary:(NSDictionary *)dictionaryToConvert;
- (NSMutableDictionary *)dictionaryToSecItemFormat:(NSDictionary *)dictionaryToConvert;
// Updates the item in the keychain, or adds it if it doesn‘t exist.
- (void)writeToKeychain;
@end
@implementation KeychainItemWrapper
@synthesize keychainItemData, genericPasswordQuery;
- (id)initWithIdentifier: (NSString *)identifier accessGroup:(NSString *) accessGroup;
{
if (self = [super init])
{
// Begin Keychain search setup. The genericPasswordQuery leverages the special user
// defined attribute kSecAttrGeneric to distinguish itself between other generic Keychain
// items which may be included by the same application.
genericPasswordQuery = [[NSMutableDictionary alloc] init];
[genericPasswordQuery setObject:(id)kSecClassGenericPassword forKey:(id)kSecClass];
[genericPasswordQuery setObject:identifier forKey:(id)kSecAttrGeneric];
// The keychain access group attribute determines if this item can be shared
// amongst multiple apps whose code signing entitlements contain the same keychain access group.
if (accessGroup != nil)
{
#if TARGET_IPHONE_SIMULATOR
// Ignore the access group if running on the iPhone simulator.
//
// Apps that are built for the simulator aren‘t signed, so there‘s no keychain access group
// for the simulator to check. This means that all apps can see all keychain items when run
// on the simulator.
//
// If a SecItem contains an access group attribute, SecItemAdd and SecItemUpdate on the
// simulator will return -25243 (errSecNoAccessForItem).
#else
[genericPasswordQuery setObject:accessGroup forKey:(id)kSecAttrAccessGroup];
#endif
}
// Use the proper search constants, return only the attributes of the first match.
[genericPasswordQuery setObject:(id)kSecMatchLimitOne forKey:(id)kSecMatchLimit];
[genericPasswordQuery setObject:(id)kCFBooleanTrue forKey:(id)kSecReturnAttributes];
NSDictionary *tempQuery = [NSDictionary dictionaryWithDictionary:genericPasswordQuery];
NSMutableDictionary *outDictionary = nil;
if (! SecItemCopyMatching((CFDictionaryRef)tempQuery, (CFTypeRef *)&outDictionary) == noErr)
{
// Stick these default values into keychain item if nothing found.
[self resetKeychainItem];
// Add the generic attribute and the keychain access group.
[keychainItemData setObject:identifier forKey:(id)kSecAttrGeneric];
if (accessGroup != nil)
{
#if TARGET_IPHONE_SIMULATOR
// Ignore the access group if running on the iPhone simulator.
//
// Apps that are built for the simulator aren‘t signed, so there‘s no keychain access group
// for the simulator to check. This means that all apps can see all keychain items when run
// on the simulator.
//
// If a SecItem contains an access group attribute, SecItemAdd and SecItemUpdate on the
// simulator will return -25243 (errSecNoAccessForItem).
#else
[keychainItemData setObject:accessGroup forKey:(id)kSecAttrAccessGroup];
#endif
}
}
else
{
// load the saved data from Keychain.
self.keychainItemData = [self secItemFormatToDictionary:outDictionary];
}
[outDictionary release];
}
return self;
}
- (void)dealloc
{
[keychainItemData release];
[genericPasswordQuery release];
[super dealloc];
}
- (void)setObject:(id)inObject forKey:(id)key
{
if (inObject == nil) return;
id currentObject = [keychainItemData objectForKey:key];
if (![currentObject isEqual:inObject])
{
[keychainItemData setObject:inObject forKey:key];
[self writeToKeychain];
}
}
- (id)objectForKey:(id)key
{
return [keychainItemData objectForKey:key];
}
- (void)resetKeychainItem
{
OSStatus junk = noErr;
if (!keychainItemData)
{
self.keychainItemData = [[NSMutableDictionary alloc] init];
}
else if (keychainItemData)
{
NSMutableDictionary *tempDictionary = [self dictionaryToSecItemFormat:keychainItemData];
junk = SecItemDelete((CFDictionaryRef)tempDictionary);
NSAssert( junk == noErr || junk == errSecItemNotFound, @"Problem deleting current dictionary." );
}
// Default attributes for keychain item.
[keychainItemData setObject:@"" forKey:(id)kSecAttrAccount];
[keychainItemData setObject:@"" forKey:(id)kSecAttrLabel];
[keychainItemData setObject:@"" forKey:(id)kSecAttrDescription];
// Default data for keychain item.
[keychainItemData setObject:@"" forKey:(id)kSecValueData];
}
- (NSMutableDictionary *)dictionaryToSecItemFormat:(NSDictionary *)dictionaryToConvert
{
// The assumption is that this method will be called with a properly populated dictionary
// containing all the right key/value pairs for a SecItem.
// Create a dictionary to return populated with the attributes and data.
NSMutableDictionary *returnDictionary = [NSMutableDictionary dictionaryWithDictionary:dictionaryToConvert];
// Add the Generic Password keychain item class attribute.
[returnDictionary setObject:(id)kSecClassGenericPassword forKey:(id)kSecClass];
// Convert the NSString to NSData to meet the requirements for the value type kSecValueData.
// This is where to store sensitive data that should be encrypted.
NSString *passwordString = [dictionaryToConvert objectForKey:(id)kSecValueData];
[returnDictionary setObject:[passwordString dataUsingEncoding:NSUTF8StringEncoding] forKey:(id)kSecValueData];
return returnDictionary;
}
- (NSMutableDictionary *)secItemFormatToDictionary:(NSDictionary *)dictionaryToConvert
{
// The assumption is that this method will be called with a properly populated dictionary
// containing all the right key/value pairs for the UI element.
// Create a dictionary to return populated with the attributes and data.
NSMutableDictionary *returnDictionary = [NSMutableDictionary dictionaryWithDictionary:dictionaryToConvert];
// Add the proper search key and class attribute.
[returnDictionary setObject:(id)kCFBooleanTrue forKey:(id)kSecReturnData];
[returnDictionary setObject:(id)kSecClassGenericPassword forKey:(id)kSecClass];
// Acquire the password data from the attributes.
NSData *passwordData = NULL;
if (SecItemCopyMatching((CFDictionaryRef)returnDictionary, (CFTypeRef *)&passwordData) == noErr)
{
// Remove the search, class, and identifier key/value, we don‘t need them anymore.
[returnDictionary removeObjectForKey:(id)kSecReturnData];
// Add the password to the dictionary, converting from NSData to NSString.
NSString *password = [[[NSString alloc] initWithBytes:[passwordData bytes] length:[passwordData length]
encoding:NSUTF8StringEncoding] autorelease];
[returnDictionary setObject:password forKey:(id)kSecValueData];
}
else
{
// Don‘t do anything if nothing is found.
NSAssert(NO, @"Serious error, no matching item found in the keychain.\n");
}
[passwordData release];
return returnDictionary;
}
- (void)writeToKeychain
{
NSDictionary *attributes = NULL;
NSMutableDictionary *updateItem = NULL;
OSStatus result;
if (SecItemCopyMatching((CFDictionaryRef)genericPasswordQuery, (CFTypeRef *)&attributes) == noErr)
{
// First we need the attributes from the Keychain.
updateItem = [NSMutableDictionary dictionaryWithDictionary:attributes];
// Second we need to add the appropriate search key/values.
[updateItem setObject:[genericPasswordQuery objectForKey:(id)kSecClass] forKey:(id)kSecClass];
// Lastly, we need to set up the updated attribute list being careful to remove the class.
NSMutableDictionary *tempCheck = [self dictionaryToSecItemFormat:keychainItemData];
[tempCheck removeObjectForKey:(id)kSecClass];
#if TARGET_IPHONE_SIMULATOR
// Remove the access group if running on the iPhone simulator.
//
// Apps that are built for the simulator aren‘t signed, so there‘s no keychain access group
// for the simulator to check. This means that all apps can see all keychain items when run
// on the simulator.
//
// If a SecItem contains an access group attribute, SecItemAdd and SecItemUpdate on the
// simulator will return -25243 (errSecNoAccessForItem).
//
// The access group attribute will be included in items returned by SecItemCopyMatching,
// which is why we need to remove it before updating the item.
[tempCheck removeObjectForKey:(id)kSecAttrAccessGroup];
#endif
// An implicit assumption is that you can only update a single item at a time.
result = SecItemUpdate((CFDictionaryRef)updateItem, (CFDictionaryRef)tempCheck);
NSAssert( result == noErr, @"Couldn‘t update the Keychain Item." );
}
else
{
// No previous item found; add the new one.
result = SecItemAdd((CFDictionaryRef)[self dictionaryToSecItemFormat:keychainItemData], NULL);
NSAssert( result == noErr, @"Couldn‘t add the Keychain Item." );
}
}
@end
标签：ios 计算机 objective-c 存储 数据
原文地址：http://blog.csdn.net/snn5love11314/article/details/45718945
