ios - App crashes on saving data in keychain -

i using keychainitemwrapper class saving data in keychain, app crashing crash log terminating app due uncaught exception 'nsinternalinconsistencyexception', reason: 'couldn't add keychain item.'

here method write data in keychain

- (void)writetokeychain {     nsdictionary *attributes = null;     nsmutabledictionary *updateitem = null;     osstatus result;      if (secitemcopymatching((cfdictionaryref)genericpasswordquery, (cftyperef *)&attributes) == noerr)     {         // first need attributes keychain.         updateitem = [nsmutabledictionary dictionarywithdictionary:attributes];         // second need add appropriate search key/values.         [updateitem setobject:[genericpasswordquery objectforkey:(id)ksecclass] forkey:(id)ksecclass];          // lastly, need set updated attribute list being careful remove class.         nsmutabledictionary *tempcheck = [self dictionarytosecitemformat:keychainitemdata];        [tempcheck removeobjectforkey:(id)ksecclass];  #if target_iphone_simulator         // remove access group if running on iphone simulator.         //          // apps built simulator aren't signed, there's no keychain access group         // simulator check. means apps can see keychain items when run         // on simulator.         //         // if secitem contains access group attribute, secitemadd , secitemupdate on         // simulator return -25243 (errsecnoaccessforitem).         //         // access group attribute included in items returned secitemcopymatching,         // why need remove before updating item.         [tempcheck removeobjectforkey:(id)ksecattraccessgroup]; #endif          // implicit assumption can update single item @ time.          result = secitemupdate((cfdictionaryref)updateitem, (cfdictionaryref)tempcheck);         nsassert( result == noerr, @"couldn't update keychain item." );     }     else     {         // no previous item found; add new one.         result = secitemadd((cfdictionaryref)[self dictionarytosecitemformat:keychainitemdata], null);          nsassert( result == noerr, @"couldn't add keychain item." );      } } 

my app crashing at

result = secitemadd((cfdictionaryref)[self dictionarytosecitemformat:keychainitemdata], null); 

with assertion error message assertion failure in -[keychainitemwrapper writetokeychain]

here values assigned in keychainitemdata

printing description of self->keychainitemdata: {     acct = "";     desc = "";     gena = "com.xyz.abc";     labl = "";     "v_data" = "abcdss-abcdss-abcdss-test-data"; } 

i know similar questions has been asked here many time nothing me.

can me out ? there other approach save data in keychain.

thanks in advance.

using self.keychainitemdata instead of keychainitemdata in method ?

- (void)writetokeychain {     nsdictionary *attributes = null;     nsmutabledictionary *updateitem = null;     osstatus result;      if (secitemcopymatching((cfdictionaryref)genericpasswordquery, (cftyperef *)&attributes) == noerr)     {         // first need attributes keychain.         updateitem = [nsmutabledictionary dictionarywithdictionary:attributes];         // second need add appropriate search key/values.         [updateitem setobject:[genericpasswordquery objectforkey:(id)ksecclass] forkey:(id)ksecclass];          // lastly, need set updated attribute list being careful remove class.         nsmutabledictionary *tempcheck = [self dictionarytosecitemformat:self.keychainitemdata];        [tempcheck removeobjectforkey:(id)ksecclass];  #if target_iphone_simulator         // remove access group if running on iphone simulator.         //          // apps built simulator aren't signed, there's no keychain access group         // simulator check. means apps can see keychain items when run         // on simulator.         //         // if secitem contains access group attribute, secitemadd , secitemupdate on         // simulator return -25243 (errsecnoaccessforitem).         //         // access group attribute included in items returned secitemcopymatching,         // why need remove before updating item.         [tempcheck removeobjectforkey:(id)ksecattraccessgroup]; #endif          // implicit assumption can update single item @ time.          result = secitemupdate((cfdictionaryref)updateitem, (cfdictionaryref)tempcheck);         nsassert( result == noerr, @"couldn't update keychain item." );     }     else     {         // no previous item found; add new one.         result = secitemadd((cfdictionaryref)[self dictionarytosecitemformat:self.keychainitemdata], null);          nsassert( result == noerr, @"couldn't add keychain item." );      } }