Send secure messages in Slack

A Slack slash command that sends a secure message in slack channels.

It uses sharelock.io to encrypt the message so that it can only be read by the people in the Slack channel that the message was posted in.

• Slack api to create the slash command.
• Webtask - Cool serverless architecture.
• Sharelock - Uses an unofficial and undocumented api to create a link to a message that can only be read by the people in the slack channel the message was created in.
• OAuth - Used to create the "Add to slack" button.

You can just add the app to slack and use it right away in Slack:

/secret [some-secret]

Or you can host your own webtask instance and run this yourself. To do that, you first need to create a webtask account and use the webtask CLI to create a new app.

Then to push changes to the app you need to

$ npm run build
$ npm run deploy

The build step inlines all local files into the one entry file and also runs the code through Babel to make it work with the Node runtime version in webtask.

Note: there's a way to make webtask bundle other files in the project, but it bundles all external modules as well which results in a very big file that the webtask uploader rejects. See auth0/wt-cli#121

Once you deploy to webtask, there are also two secret variables that need to be set:

1. SLACK_VERIFICATION - Slack verification code to match the incoming message.
2. SLACK_SECRET - The app's secret. You can get them both from the Slack api dashboard.

The app requests the following Slack permissions:

1. commands - To be able to install itself in your team.
2. channels:read - To get a list of users in the channel the message was posted in.
3. groups:read - To get a list of users in the group the message was posted in.
4. im:read - In case of direct message, get the other user.
5. users:read - Get the email addresses of the users.
6. users:read.email - Email needs to be asked explicitly.