使用 KeychainItemWrapper iPhone SDK 时收到 SIGABRT

Question

我正在编写一个应用程序，它使用“KeychainItemWrapper”类以安全的方式存储登录凭据。这是管理钥匙串对象的代码：

- (IBAction)saveFields {
wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"username" accessGroup:nil];
[wrapper setObject:[self.password text] forKey:(id)kSecAttrAccount];
[wrapper release];
wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"password" accessGroup:nil];
[wrapper setObject:[self.password text] forKey:(id)kSecAttrAccount];
[wrapper release];

[self dismissModalViewControllerAnimated:YES];
}

- (BOOL)isUserLogged {
wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"username" accessGroup:nil];
if ( [[wrapper objectForKey:(id)kSecAttrAccount] isEqualToString:@""] ) {
    return NO;
} else {
    username = [NSString stringWithString:[wrapper objectForKey:(id)kSecAttrAccount]];
    [wrapper release];
}
wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"password" accessGroup:nil];
if ( [[wrapper objectForKey:(id)kSecAttrAccount] isEqualToString:@""] ) {
    return NO;
} else {
    password = [NSString stringWithString:[wrapper objectForKey:(id)kSecValueData]];
    [wrapper release];
}

return YES;
}

当我尝试在钥匙串中写入凭据时，我收到 SIGABRT 错误，如下所示：

// KeychainItemWrapper.m
// - (void)writeToKeychain;
result = SecItemAdd( (CFDictionaryRef)[self dictionaryToSecItemFormat:keychainItemData], NULL );

Answer 1

显然，故障出在 NSAssert() 块上。评论该行解决了问题。