class Mailgun::OptInHandler

Public: Provides methods for creating and handling opt-in URLs,

particularlly for mailing lists.

See: github.com/mailgun/mailgun-ruby/blob/master/OptInHandler.md

Public Class Methods

generate_hash(mailing_list, secret_app_id, recipient_address) click to toggle source

Generates a hash that can be used to validate opt-in recipients. Encodes all the necessary data in the URL.

@param [String] mailing_list The mailing list the user should be subscribed to. @param [String] secret_app_id A secret passphrase used as a constant for the hash. @param [Hash] recipient_address The address of the user that should be subscribed. @return [String] A url encoded URL suffix hash.

# File lib/mailgun/lists/opt_in_handler.rb, line 20
def self.generate_hash(mailing_list, secret_app_id, recipient_address)
  inner_payload = { 'l' => mailing_list, 'r' => recipient_address }

  inner_payload_encoded = Base64.encode64(JSON.generate(inner_payload))

  sha1_digest = OpenSSL::Digest.new('sha1')
  digest = OpenSSL::HMAC.hexdigest(sha1_digest, secret_app_id, inner_payload_encoded)

  outer_payload = { 'h' => digest, 'p' => inner_payload_encoded }

  outer_payload_encoded = Base64.encode64(JSON.generate(outer_payload))

  CGI.escape(outer_payload_encoded)
end
validate_hash(secret_app_id, unique_hash) click to toggle source

Validates the hash provided from the generate_hash method.

@param [String] secret_app_id A secret passphrase used as a constant for the hash. @param [Hash] unique_hash The hash from the user. Likely via link click. @return [Hash or Boolean] A hash with 'recipient_address' and 'mailing_list', if validates. Otherwise, boolean false.

# File lib/mailgun/lists/opt_in_handler.rb, line 40
def self.validate_hash(secret_app_id, unique_hash)
  outer_payload = JSON.parse(Base64.decode64(CGI.unescape(unique_hash)))

  sha1_digest = OpenSSL::Digest.new('sha1')
  generated_hash = OpenSSL::HMAC.hexdigest(sha1_digest, secret_app_id, outer_payload['p'])

  inner_payload = JSON.parse(Base64.decode64(CGI.unescape(outer_payload['p'])))

  hash_provided = outer_payload['h']

  if generated_hash == hash_provided
    return { 'recipient_address' => inner_payload['r'], 'mailing_list' => inner_payload['l'] }
  end
  false
end