Merge pull request #374 from alecostard/feat/hs-error-message

handle non binary hmac sha key error

lib/joken/error.ex

@@ -92,6 +92,13 @@ defmodule Joken.Error do
     See `Joken.Config.validate/2` for more information on Context
     """
 
+  def message(%__MODULE__{reason: :algorithm_needs_binary_key}),
+    do: """
+    Couldn't create a signer because key is not binary.
+
+    HMAC SHA algorithms need a binary key.
+    """
+
   def message(%__MODULE__{reason: :wrong_key_parameters}),
     do: """
     Couldn't create a signer because there are missing parameters.

lib/joken/signer.ex

@@ -80,6 +80,9 @@ defmodule Joken.Signer do
     )
   end
 
+  def create(alg, _key, _headers) when alg in @hs_algorithms,
+    do: raise(Joken.Error, :algorithm_needs_binary_key)
+
   def create(alg, %{"pem" => pem}, headers) when alg in @map_key_algorithms do
     raw_create(
       alg,

test/joken_signer_test.exs

@@ -81,6 +81,12 @@ defmodule Joken.Signer.Test do
     end
   end
 
+  test "raise when key is invalid" do
+    assert_raise Error, Error.message(%Error{reason: :algorithm_needs_binary_key}), fn ->
+      Signer.create("HS256", %{})
+    end
+  end
+
   test "raise when parsing invalid algorithm from configuration" do
     assert_raise Error, Error.message(%Error{reason: :unrecognized_algorithm}), fn ->
       Signer.parse_config(:bad_algorithm)