orta/cocoapods-keys

A key value store for enviroment and application keys.

Its good security practice to keep production keys out of developer hands. CocoaPods-keys makes it easy to have per-user config settings stored securely in the developer's keychain, and not in the application source. It is a plugin that once installed will run on every pod install or pod update.

Alternatives

CocoaPods Keys has had a great run since its creation in 2014, and still works perfectly fine today. If you're interested in a fresh re-think of the concept, check out https://github.com/rogerluan/arkana

Requirements

Requires CocoaPods 0.36+

Installation

$ gem install cocoapods-keys

How it works

Key names are stored in ~/.cocoapods/keys/ and key values in the OS X keychain. When you run pod install or pod update, an Objective-C class is created with scrambled versions of the keys, making it difficult to just dump the contents of the decrypted binary and extract the keys. At runtime, the keys are unscrambled for use in your app.

The generated Objective-C classes are stored in the Pods/CocoaPodsKeys directory, so if you're checking in your Pods folder, just add Pods/CocoaPodsKeys to your .gitignore file. CocoaPods-Keys supports integration in Swift or Objective-C projects.

Usage

Using the new Plugin API in CocoaPods we can automate a lot of the fiddly bits away. You define what keys you want inside your Podfile and Keys will detect what keys are not yet set. If you need to specify a different project name from the target name, use the key :target to specify it.

plugin 'cocoapods-keys', {
  :project => "Eidolon",
  :keys => [
    "ArtsyAPIClientSecret",
    "ArtsyAPIClientKey",
    "HockeyProductionSecret",
    "HockeyBetaSecret",
    "MixpanelProductionAPIClientKey",
    ...
  ]}

Please do not use dash in key names (Reason why here in this issue #197).

For example convert any key like this WRONGLY-DEFINED-KEY to CorrectlyDefinedKey.

Then running pod install will prompt for the keys not yet set and you can ensure everyone has the same setup.

Alternative Usage

You can save keys on a per-project basis by running the command:

$ bundle exec pod keys set KEY VALUE

You can list all known keys by running:

$ bundle exec pod keys

For example:

  $ cd MyApplication
  $ bundle exec pod keys set "NetworkAPIToken" "AH2ZMiraGQbyUd9GkNTNfWEdxlwXcmHciEOH"
  Saved NetworkAPIToken to MyApplication.

  $ bundle exec pod keys set "AnalyticsToken" "6TYKGVCn7sBSBFpwfSUCclzDoSBtEXw7"
  Saved AnalyticsToken to MyApplication.

  $ bundle exec pod keys
  Keys for MyApplication
   ├  NetworkAPIToken - AH2ZMiraGQbyUd9GkNTNfWEdxlwXcmHciEOH
   └  AnalyticsToken - 6TYKGVCn7sBSBFpwfSUCclzDoSBtEXw7

  GIFs - /Users/orta/dev/mac/GIFs
   └ redditAPIToken & mixpanelAPIToken

After the next pod install or pod update keys will add a new Keys pod to your Pods project, supporting both static libraries and frameworks. Note you have to include plugin 'cocoapods-keys' in the Podfile for Keys to register that it should work. This provides an API to your keys from Cocoa code. For example the application code above would look like:

#import "ORAppDelegate.h"
#import <Keys/MyApplicationKeys.h>
#import <ARAnalytics/ARAnalytics.h>

@implementation ORAppDelegate

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    MyApplicationKeys *keys = [[MyApplicationKeys alloc] init];
    [ARAnalytics setupWithAnalytics:@{
        ARGoogleAnalyticsID : keys.analyticsToken;
    }];
}

@end

Some documentation is also available to use cocoapods-keys in Swift projects.

Other commands

CocoaPods-keys has 3 other commands:

• bundle exec pod keys get [key] [optional project] Which will output the value of the key to STDOUT, useful for scripting.

• bundle exec pod keys rm [key] [optional project] Will remove a key from a project.

  If Wildcards are included, it will remove the keys matching the pattern. E.g.: bundle exec pod keys rm "G*og*" will remove all the keys that begin with 'G', have 'og' in the middle and end with anything. To nuke all the keys, run either bundle exec pod keys rm "*" or bundle exec pod keys rm --all

• bundle exec pod keys generate [optional project] Will generate the obfuscated Objective-C keys class (mainly used internally).

Continuous Integration

It's rarely a good idea to mess around with the keychain in your CI, so keys will look for an environment var with the same string before looking in the keychain. Also you could create a .env file in your project folder.

Maintainance State

CocoaPods Keys is effectively "done" software from Artsy's perspective. It has done everything we've needed for years. So, I wouldn't recommend making issues requesting new features, simply because we won't be building them ourselves. We'll definitely continue making sure it works etc though, we use it in production.

Security

Key security is difficult. Right now even the biggest apps get their keys leaked. This is neatly summed up by John Adams of the Twitter Security Team on Quora.

Putting this in the context of, "should you be storing keys in software", is more appropriate. Many companies do this. It's never a good idea.

When developers do that, other developers can use debuggers and string searching commands to extract those keys from the running application. There are numerous talks on how to do that, but leave that as an exercise to the reader to find those talks.

Many people believe that obfuscating these keys in code will help. It usually won't because you can just run a debugger and find the fully functional keys.

So in summary, the ideal way to store keys is to not store keys. In reality though most Apps embed keys, and this does that and adds some rudimentary obfuscation to the keys. A well motivated app cracker could probably extract this within a few minutes however.

Thanks

This was built with a lot of help from @segiddins, @ashfurrow and @marcelofabri.