Sometimes when I run an application on device from Xcode I would try to access the keychain but fail due to error -34018. This doesn't match any of the documented keychain error codes and can't be consistently reproduced. (happens maybe 30% of the time, and it's not clear to me why it happens). What makes debugging this problem very difficult is the total lack of documentation. Any idea what causes this and how to fix it? I'm using Xcode 5 and running iOS 7.0.4 on device.
There is an open issue about this here: https://github.com/soffes/sskeychain/issues/52
EDIT: Adding keychain access code per request
I'm using the SSKeychain library for interfacing with keychain. Here's the snippet.
#define SERVICE @"default"
@implementation SSKeychain (EXT)
+ (void)setValue:(NSString *)value forKey:(NSString *)key {
NSError *error = nil;
BOOL success = NO;
if (value) {
success = [self setPassword:value forService:SERVICE account:key error:&error];
} else {
success = [self deletePasswordForService:SERVICE account:key error:&error];
}
NSAssert(success, @"Unable to set keychain value %@ for key %@ error %@", value, key, error);
if (!success) {
LogError(@"Unable to set value to keychain %@", error);
}
LogTrace(@"Will set keychain account %@. is to nil? %d", key, value == nil);
if (value == nil)
LogWarn(@"Setting keychain %@ to nil!!!", key);
}
+ (NSString *)valueForKey:(NSString *)key {
NSError *error = nil;
NSString *value = [self passwordForService:SERVICE account:key error:&error];
if (error && error.code != errSecItemNotFound) {
NSAssert(!error, @"Unable to retrieve keychain value for key %@ error %@", key, error);
LogError(@"Unable to retrieve keychain value for key %@ error %@", key, error);
}
return value;
}
+ (BOOL)removeAllValues {
LogInfo(@"Completely Reseting Keychain");
return [[self accountsForService:SERVICE] all:^BOOL(NSDictionary *accountInfo) {
return [self deletePasswordForService:SERVICE account:accountInfo[@"acct"]];
}];
}
@end
Vast majority of the time it's just fine. Sometimes I'll hit the assertion failures where I'm unable to either write to or read from keychain, causing critical assertion failure.
After inspecting the source code. I have noticed that the keychain features are accessed through a security daemon that runs in its own process (separated from the app process).
Your app and the securityd process 'talk' together through a technology called XPC.
If necessary, the securityd is launched via the well-known launchd command by XPC. You can probably check that the daemon is running in the Activity Monitor App (if running in Simulator of course) and that its parent process is launchd.
My guess here is that it is possible that for any unknown reason the security daemon fails to start or do it too slowly and is not ready when you try to use it.
Maybe you could think on how to pre-launch the daemon.
I apologize for not being more precise. I hope it could help you to go a bite further in your investigations.