Keychain错误：如何使用Objective C从MAC应用程序在SYSTEM Keychain中存储密码

Question

我正在尝试从我的MAC应用程序创建VPN连接，为此我需要在SYSTEM Keychain中存储VPN共享密钥和VPN密码。

我尝试使用MACOSVPN Code中的Keychain Class，但它返回错误代码-61说您没有写入权限。

这是我的代码。如果我在某个地方出错，请纠正我。

// A generic method to create Keychain Items holding Network service passwords
+ (int) createItem:(NSString*)label withService:(NSString*)service account:(NSString*)account description:(NSString*)description andPassword:(NSString*)password {

// This variable will hold all sorts of operation status responses
  OSStatus status;

  // Converting the NSStrings to char* variables which we will need later
  const char *labelUTF8 = [label UTF8String];
  const char *serviceUTF8 = [service UTF8String];
  const char *accountUTF8 = [account UTF8String];
  const char *descriptionUTF8 = [description UTF8String];
  const char *passwordUTF8 = [password UTF8String];

  // This variable is soon to hold the System Keychain
  SecKeychainRef keychain = NULL;

  status = SecKeychainCopyDomainDefault(kSecPreferencesDomainSystem, &keychain);
  if (status == errSecSuccess) {
    NSLog(@"Succeeded opening System Keychain");
  } else {
    NSLog(@"Could not obtain System Keychain: %@", SecCopyErrorMessageString(status, NULL));
    return 60;
  }

  NSLog(@"Unlocking System Keychain");
  status = SecKeychainUnlock(keychain, 0, NULL, FALSE);
  if (status == errSecSuccess) {
    NSLog(@"Succeeded unlocking System Keychain");
  } else {
    NSLog(@"Could not unlock System Keychain: %@", SecCopyErrorMessageString(status, NULL));
    return 61;
  }

  // This variable is going to hold our new Keychain Item
  SecKeychainItemRef item = nil;

    SecAccessRef access = nil;
  status = SecAccessCreate(CFSTR("Some VPN Test"), (__bridge CFArrayRef)(self.trustedApps), &access);

  if(status == noErr) {
    NSLog(@"Created empty Keychain access object");
  } else {
    NSLog(@"Could not unlock System Keychain: %@", SecCopyErrorMessageString(status, NULL));
    return 62;
  }

  // Putting together the configuration options
  SecKeychainAttribute attrs[] = {
{kSecLabelItemAttr, (int)strlen(labelUTF8), (char *)labelUTF8},
{kSecAccountItemAttr, (int)strlen(accountUTF8), (char *)accountUTF8},
{kSecServiceItemAttr, (int)strlen(serviceUTF8), (char *)serviceUTF8},
{kSecDescriptionItemAttr, (int)strlen(descriptionUTF8), (char *)descriptionUTF8},
  };

  SecKeychainAttributeList attributes = {sizeof(attrs) / sizeof(attrs[0]), attrs};


  status = SecKeychainItemCreateFromContent(kSecGenericPasswordItemClass, &attributes, (int)strlen(passwordUTF8), passwordUTF8, keychain, access, &item);

  if(status == noErr) {
    NSLog(@"Successfully created Keychain Item");
  } else {
    //----------- ERROR ---------//
    // Here i got error with error code -61 Saying You do not have write access 
    //---------------------------//
    NSLog(@"Creating Keychain item failed: %@", SecCopyErrorMessageString(status, NULL));
    return 63;
  }
  return 0;
}

+ (NSArray*) trustedApps {
  NSMutableArray *apps = [NSMutableArray array];
  SecTrustedApplicationRef app;
  OSStatus err;

  for (int i = 0; i < (sizeof(trustedAppPaths) / sizeof(*trustedAppPaths)); i++) {
    err = SecTrustedApplicationCreateFromPath(trustedAppPaths[i], &app);
    if (err == errSecSuccess) {
      //NSLog(@"SecTrustedApplicationCreateFromPath succeeded: %@", SecCopyErrorMessageString(err, NULL));
    } else {
      NSLog(@"SecTrustedApplicationCreateFromPath failed: %@", SecCopyErrorMessageString(err, NULL));
    }

    [apps addObject:(__bridge id)app];
  }

  return apps;
}