hmacauth

HTTP middleware in Go for Rails-compatible HMAC authentication

Share a secret key and authenticate rails clients in go

**Rails Side

require 'active_support/all'
class JSONSerializer
  class << self
    def dump(value)
      ActiveSupport::JSON.encode(value)
    end

    def load(value)
      ActiveSupport::JSON.decode(value)
    end
  end
end
verifier = ActiveSupport::MessageVerifier.new('testkey', :serializer => JSONSerializer)
expiry_time = (Time.now + 1.hour).to_i
user_id = 12345
# expiry epoch must be first field in token
# all entries in token array must be integers
# put whatever else you want in the token to validate the credentials (like a matching username)
token = verifier.generate([expiry_time, user_id])
params[:token] = token

Go side

hmacauth.Authenticate takes the message verifier key, the URL param from which to pull out the HMAC token, and the protected HTTP handler function that takes an extra parameter: the original decoded token as a string. In this case the token would need to be JSON decoded still.

handler := hmacauth.Authenticate("testkey", "token", func(response http.ResponseWriter, request *http.Request, token string) {
  response.Write([]byte(token))
})