Module: MosEisley::SlackEvent

Defined in:
lib/slack.rb

Class Method Summary collapse

Class Method Details

.parse_http_body(b, t) ⇒ Object 



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# File 'lib/slack.rb', line 28

def self.parse_http_body(b, t)
  case t
  when 'application/json'
    b
  when 'application/x-www-form-urlencoded'
    JSON.fast_generate(URI.decode_www_form(b).to_h)
  when 'application/xml'
    require 'rexml/document'
    REXML::Document.new(b)
  else
    b
  end
end

.validate(e) ⇒ Hash

Validate incoming Slack request, decodes the body then into JSON

Parameters:

  • e (Hash) —

    original AWS API GW event object

Returns:

  • (Hash) —

    [Bool], msg: [String], json: [String], event: [Hash]



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# File 'lib/slack.rb', line 10

def self.validate(e)
  t = e.dig('headers', 'x-slack-request-timestamp')
  return {valid?: false, msg: 'Invalid request.'} if t.nil?
  if (Time.new - Time.at(t.to_i)).abs > 300
    return {valid?: false, msg: 'Request too old.'}
  end
  b = e['isBase64Encoded'] ? Base64.decode64(e['body']) : e['body']
  s = "v0:#{t}:#{b}"
  k = ENV['SLACK_SIGNING_SECRET']
  sig = "v0=#{OpenSSL::HMAC.hexdigest('sha256', k, s)}"
  if e.dig('headers', 'x-slack-signature') != sig
    return {valid?: false, msg: 'Invalid signature.'}
  end
  b = SlackEvent.parse_http_body(b, e.dig('headers', 'content-type'))
  h = JSON.parse(b, {symbolize_names: true})
  {valid?: true, msg: 'Validated.', json: b, event: h}
end