IOS Keychain Understanding and code examples

The understanding of keychain can be referred to http://my.oschina.net/w11h22j33/blog/206713

The article uses keychain to save the user name and password, the user name is placed in the attribute, the password is placed in the password entry, and I personally feel that there is a problem, in order to respect the use of their own code, but also to help read the other readers of the text better understanding, I amended the code as follows:

Storage/Add-(Ibaction) saveclicked: (ID) sender{if (_nametf.text.length > 0 && _psdtf.text.length > 0) {                nsmutabledictionary* dic = [Nsmutabledictionary dictionary];        [DiC setobject: (__bridge_transfer ID) ksecclassgenericpassword forkey: (__bridge_transfer ID) ksecclass];        [DiC setobject:_nametf.text Forkey: (__bridge_transfer ID) ksecattraccount];                [dic Setobject:[_psdtf.text datausingencoding:nsutf8stringencoding] Forkey: (__bridge_transfer ID) kSecValueData];        Osstatus s = Secitemadd ((__bridge_retained cfdictionaryref) dic, NULL);    NSLog (@ "%d", s);  }}//Get/Query-(ibaction) showclicked: (ID) sender{if (_nametf.text.length > 0) {nsdictionary* query = [nsdictionary Dictionarywithobjectsandkeys: (__bridge_transfer ID) Ksecclassgenericpassword, (__bridge_tra                               Nsfer ID) Ksecclass, _nametf.text, (__bridge_transfer ID) ksecattraccount, KcfbOoleantrue, Ksecreturnattributes,nil];        Cftyperef result = nil;                Osstatus s = secitemcopymatching ((__bridge_retained cfdictionaryref) query, &result);        NSLog (@ "%d", s);                NSLog (@ "%@", result); if (s = = NOERR) {//through the user to determine whether the item item exists nsmutabledictionary* dic = [nsmutabledictionary dictionarywithdictionary: (__b            Ridge_transfer ID) result];            [DiC setobject: (__bridge_transfer ID) kcfbooleantrue forkey: (__bridge_transfer ID) ksecreturndata];                        [DiC setobject:[query Objectforkey: (__bridge_transfer ID) ksecclass] forkey: (__bridge_transfer ID) kSecClass];                        Cfdataref dataref = NULL;                                if (secitemcopymatching (__bridge_retained cfdictionaryref) dic, (cftyperef*) &dataref) = = NOERR) {                NSData *data = (__bridge_transfer id) dataref;                                NSLog (@ "%ld", data.length); NSLog (@ "%@", [[NSString alloc] initwithdata:data enCoding:nsutf8stringencoding]);                               }}}else{nsdictionary* query = [nsdictionary Dictionarywithobjectsandkeys: (__bridge_transfer ID) Ksecclassgenericpassword, (__bridge_transfer ID) Ksecclass, (_ _bridge_transfer ID) Ksecmatchlimitall, (__bridge_transfer ID) ksecmatchlimit, (__bridge_trans                Fer id) kcfbooleantrue, (__bridge_transfer ID) Ksecreturnattributes,nil];        Cfarrayref result = NULL;                Osstatus s = secitemcopymatching ((__bridge_retained cfdictionaryref) query, (cftyperef*) &result);        Nsarray *array = (__bridge_transfer nsarray*) result;//(can traverse all keychain items) NSLog (@ "%d", s);    NSLog (@ "%@", result); }}//Delete-(ibaction) delclicked: (ID) sender{if (_nametf.text.length > 0) {nsdictionary* query = [nsdic       Tionary Dictionarywithobjectsandkeys: (__bridge_transfer ID) ksecclassgenericpassword,ksecclass,                        _nametf.text,ksecattraccount,nil];        Osstatus status = Secitemdelete ((__bridge_retained cfdictionaryref) query);    NSLog (@ "%d", status);        }}//-(Ibaction) modifyclicked: (ID) sender{if (_nametf.text.length > 0 && _psdtf.text.length > 0) { nsdictionary* query = [nsdictionary Dictionarywithobjectsandkeys: (__bridge_transfer ID) Ksecclassgenericpassword, (__bridge_transfer ID) ksecclass, _nametf.text, (__bridge_transfer ID) Ksecattraccount, (__bridge_transfer ID) kcfbooleantrue, (__bridge_transfer ID) ksecreturnat                Tributes,nil];        Cftyperef result = nil; if (secitemcopymatching (__bridge_retained cfdictionaryref) query, &result) = = NOERR)//exist only modify {//settings need more            New attribute list, be sure to delete ksecclass, because can not update should not field, otherwise will error nsmutabledictionary* update = [[Nsmutabledictionary alloc]init]; [Update setobject:[_psdtf.tExt datausingencoding:nsutf8stringencoding] Forkey: (__bridge_transfer ID) ksecvaluedata];                        [Update Removeobjectforkey: (__bridge_transfer ID) ksecclass];            Set the find condition, which is to find the keychain item according to this condition nsmutabledictionary* updateItem = [[Nsmutabledictionary alloc]init];            [UpdateItem setobject:[query Objectforkey: (__bridge_transfer ID) ksecclass] forkey: (__bridge_transfer ID) kSecClass];                        [UpdateItem setobject:_nametf.text Forkey: (__bridge_transfer ID) ksecattraccount]; Parameter one means to look for virtual, parameter two means the updated value osstatus status = Secitemupdate ((__bridge_retained cfdictionaryref) UpdateItem, (__bridge            _retained cfdictionaryref) update);        NSLog (@ "%d", status); }    }}

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

IOS Keychain Understanding and code examples