IOS開發之——keychain使用介紹

標籤：

 iOS的keychain服務提供了一種安全的儲存私密資訊（密碼，序號，認證等）的方式。每個ios程式都有一個獨立的keychain儲存。從ios 3.0開始，跨程式分享keychain變得可行。

使用蘋果官方發布的KeychainItemWrapper或者SFHFKeychainUtils很方便。

蘋果已經有現成的類封裝好了keychain,KeychainItemWrapper.h和KeychainItemWrapper.m檔案,可以在GenericKeychain執行個體裡找到。

 下面就使用keychain來實現存取使用者名稱和密碼。

 

代碼如下：

 

DMKeyChain.h

#import <Foundation/Foundation.h>
#import <Security/Security.h>
@interface DMKeyChain : NSObject
/**
 *  儲存資料
 *
 *  @param service key值
 *  @param data    儲存值
 */
+ (void)save:(NSString *)service data:(id)data;
/**
 *  讀取資料
 *
 *  @param service key值
 *
 *  @return 儲存的值
 */
+ (id)load:(NSString *)service ;
/**
 *  刪除某個資料
 *
 *  @param service 對應的key
 */
+ (void)delete:(NSString *)service;
@end

 

 

DMKeyChain.m

#import "DMKeyChain.h"

@implementation DMKeyChain
+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
    return [NSMutableDictionary dictionaryWithObjectsAndKeys:
            (__bridge_transfer id)kSecClassGenericPassword,(__bridge_transfer id)kSecClass,
            service, (__bridge_transfer id)kSecAttrService,
            service, (__bridge_transfer id)kSecAttrAccount,
            (__bridge_transfer id)kSecAttrAccessibleAfterFirstUnlock,(__bridge_transfer id)kSecAttrAccessible,
            nil];
}

+ (void)save:(NSString *)service data:(id)data {
    //Get search dictionary
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    //Delete old item before add new item
    SecItemDelete((__bridge_retained CFDictionaryRef)keychainQuery);
    //Add new object to search dictionary(Attention:the data format)
    [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(__bridge_transfer id)kSecValueData];
    //Add item to keychain with the search dictionary
    SecItemAdd((__bridge_retained CFDictionaryRef)keychainQuery, NULL);
}

+ (id)load:(NSString *)service {
    id ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    //Configure the search setting
    [keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge_transfer id)kSecReturnData];
    [keychainQuery setObject:(__bridge_transfer id)kSecMatchLimitOne forKey:(__bridge_transfer id)kSecMatchLimit];
    CFDataRef keyData = NULL;
    if (SecItemCopyMatching((__bridge_retained CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
        @try {
            ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge_transfer NSData *)keyData];
        } @catch (NSException *e) {
            NSLog(@"Unarchive of %@ failed: %@", service, e);
        } @finally {
        }
    }
    return ret;
}

+ (void)delete:(NSString *)service {
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    SecItemDelete((__bridge_retained CFDictionaryRef)keychainQuery);
}
@end

 

IOS開發之——keychain使用介紹