updating kSecValueData in iOS using secItemUpdate Error Code -50 - ios

Question

I am at a loss here, I create a keychain query, add the item if it does not already exist, then I try and update kSecValueData with a test string and it returns error code -50, which means there was an error with one or more parameters I entered...
NSString *initial = #"";
NSData *initData = [initial dataUsingEncoding:NSUTF8StringEncoding];
//Create Search Dictionary For Phone Number...
NSDictionary *secPhoneItem = #{ (__bridge id)kSecClass : (__bridge id)kSecClassGenericPassword,
(__bridge id)kSecReturnData : (__bridge id)kCFBooleanTrue,
(__bridge id)kSecValueData : initData
};
//Check to see if keychain already exists by using secItemCopyMatching and associated status code
OSStatus PhoneCheckStatus = SecItemCopyMatching((__bridge CFDictionaryRef)secPhoneItem, NULL);
//Check Status Code Phone
if (PhoneCheckStatus == errSecItemNotFound) //If Phone Keychain Item Does Not already Exist
{
//Add Phone Number To Keychain
SecItemAdd((__bridge CFDictionaryRef)secPhoneItem, NULL);
}
//Update Phone Number to String
NSString *string = #"Test String";
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *attributesForUpdate = #{
(__bridge id)kSecValueData : data
};
OSStatus news = SecItemUpdate((__bridge CFDictionaryRef)secPhoneItem, (__bridge CFDictionaryRef)attributesForUpdate);
NSLog(#"Update Status Code: %ld", news);
If anyone knows why or can shed some info, the only lead I have right now from Apples Documentation is that you can only pass real attributes into secItemUpdate(), not "meta" attributes.

Answer 1

So after rereading the documentation, I found out that the key-value pair (__bridge id)kSecReturnData : (__bridge id)kCFBooleanTrue cannot be used in the secItemUpdate()' query parameter. To fix my problem and help better refine the search, I added the key-value pair(__bridge id)kSecAttrDescription : someUniqueData` to the search query along with the class item specification then making my attributes dictionary returned status 0: SUCCESS!!!

Answer 2

Key and certificate Attribute Update-----------
for the normal SecItemUpdate code gave two error:-25300(item not found),-50(trying to update more than one item in one update method)
here is the code for update method:
//Search Dictionary.....
NSMutableDictionary *searchDict = [[NSMutableDictionary alloc] init];
NSData *privateKeyTag = [NSData dataWithBytes:[keyIdentifier UTF8String] length:keyIdentifier.length];
[searchDict setObject:privateKeyTag forKey:(__bridge id)kSecAttrApplicationTag];
[searchDict setObject:(__bridge id)kSecClassKey forKey:(__bridge id)kSecClass];
[searchDict setObject:(__bridge id)(kSecAttrKeyTypeRSA) forKey:(__bridge id<NSCopying>)(kSecAttrKeyType)];
[searchDict setObject:(__bridge id)kSecMatchLimitOne forKey:(__bridge id)kSecMatchLimit];
[searchDict setObject:(__bridge id)kCFBooleanTrue forKey:(__bridge id<NSCopying>)(kSecReturnData)];
status = SecItemCopyMatching((__bridge CFDictionaryRef)searchDict, (CFTypeRef*)&item);
if (status != errSecSuccess)
{//your code for error handling }
//dictionary for the attribute that are going to update in key of certificate
//if youwant to update your passward the add the passward attribute
NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly,kSecAttrAccessible, nil];
/*removing the some of the from the searching dictionary*/
[searchDict removeObjectForKey:(__bridge id)kSecReturnData];
[searchDict removeObjectForKey:(__bridge id)kSecMatchLimit];
//Creating the Array for every item in the keychain that is cert of key as Search Dictionary
NSArray *secItemclasses= #[(__bridge id)kSecClassKey,(__bridge id)kSecClassCertificate];
for (id secitemclass in secItemclasses) {
//updating the key as well as certificate attribute....//
status = SecItemUpdate((__bridge CFDictionaryRef)searchDict,(__bridge CFDictionaryRef)dict);
}
if(status != errSecSuccess)