5

次のコードを使用して、iPhoneキーチェーンからログイン資格情報を取得します。

KeychainItemWrapper *wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"Test" accessGroup:nil];
NSString *username = [wrapper objectForKey:(id)kSecAttrAccount];
NSString *password = [wrapper objectForKey:(id)kSecValueData];
[wrapper release];

ユーザーが初めてアプリを起動したとき、ユーザー名もパスワードもキーチェーンから取得できなかったため、と同じである必要があるという印象を受けusernameましpasswordたnil。ただし、を使用してこれらの変数を出力することはできませんでしたNSLog。

助言がありますか？

4

4 に答える 4

8 
KeychainItemWrapper *wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"Test" accessGroup:nil];
NSString *username = [wrapper objectForKey:(id)kSecAttrAccount];
NSString *password = [wrapper objectForKey:(id)kSecValueData];

// initially all these are empty
NSLog(@"username - %@", username); // username - 
NSLog(@"password - %@", password); // password - 

//if empty set your credentials
if ( [username isEqualToString:@""] ) {
    [wrapper setObject:@"your username here" forKey:(id)kSecAttrAccount];
}
if ( [password isEqualToString:@""] ) {
    [wrapper setObject:@"your password here" forKey:(id)kSecValueData];
}

//get the latest credentials - now you have the set values
username = [wrapper objectForKey:(id)kSecAttrAccount];
password = [wrapper objectForKey:(id)kSecValueData];

NSLog(@"username - %@", username); // username - your username here
NSLog(@"password - %@", password); // password - your password here

// reset your keychain items - if  needed
[wrapper resetKeychainItem];
[wrapper release];
于 2010-08-31T04:59:00.633 に答える
5

あなたの仮定は間違っています-作成時に、「kSecAttrAccount」と「kSecValueData」はnilに設定されていません。それらは空の文字列（つまり、 ""）に設定されます。したがって、このコードはtrueを返します。

[username isEqualToString:@""]    // returns true on creation
于 2012-02-21T17:28:16.520 に答える
1

私にとっても同じエラーです。ファイル内のwriteToKeychain関数の戻り値を確認しました。KeychainItemWrapper.m戻り値はに等しいerrSecDuplicateItem。理由はわかりませんが、SecItemCopyMatching機能が正常に動作していないようです。（他のプロジェクトが正しく機能している場合）。

私は今のところコードを変更し、私のために働いています：ファイル内writeToKeychainのコードを更新しました：KeychainItemWrapper.m

- (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);
        NSLog(@"%@",keychainItemData);
        NSLog(@"res : %ld",result);
        if(result == (OSStatus)errSecDuplicateItem)
        {
            NSLog(@"updttttt");
            // 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." );
            return;
        }//if(result == errSecDuplicateItem)*
        NSAssert( result == noErr, @"Couldn't add the Keychain Item." );
    }
}
于 2012-08-26T14:40:57.257 に答える
0

値が最初にnilの場合、

if ( [username isEqualToString:@""] )

FALSEと評価されます。あなたが使うことができます

if (!username)

代わりは

于 2012-01-11T11:53:38.507 に答える