refactor: make pubkey optional for decoded_json in keystore in decode_str! function

lib/keystore.ex

@@ -24,10 +24,14 @@ defmodule Keystore do
 
     privkey = decrypt!(decoded_json["crypto"], password)
 
-    pubkey = Map.fetch!(decoded_json, "pubkey") |> parse_binary!()
-
     {:ok, derived_pubkey} = Bls.derive_pubkey(privkey)
 
+    pubkey =
+      case Map.has_key?(decoded_json, "pubkey") do
+        true -> Map.get(decoded_json, "pubkey") |> parse_binary!()
+        false -> derived_pubkey
+      end
+
     if derived_pubkey != pubkey do
       raise("Keystore secret and public keys don't form a valid pair")
     end

test/unit/keystore_test.exs

@@ -92,4 +92,36 @@ defmodule Unit.KeystoreTest do
     {:ok, signature} = Bls.sign(privkey, digest)
     assert Bls.valid?(pubkey, digest, signature)
   end
+
+  test "eip scrypt without pubkey test vector" do
+    scrypt_json =
+      Jason.decode!(@pbkdf2_json)
+      |> Map.delete("pubkey")
+      |> Jason.encode!()
+
+    {pubkey, privkey} = Keystore.decode_str!(scrypt_json, @eip_password)
+
+    assert privkey == @eip_secret
+    assert pubkey == @pubkey
+
+    digest = :crypto.hash(:sha256, "test message")
+    {:ok, signature} = Bls.sign(privkey, digest)
+    assert Bls.valid?(pubkey, digest, signature)
+  end
+
+  test "eip pbkdf2 without pubkey test vector" do
+    pbkdf2_json =
+      Jason.decode!(@pbkdf2_json)
+      |> Map.delete("pubkey")
+      |> Jason.encode!()
+
+    {pubkey, privkey} = Keystore.decode_str!(pbkdf2_json, @eip_password)
+
+    assert privkey == @eip_secret
+    assert pubkey == @pubkey
+
+    digest = :crypto.hash(:sha256, "test message")
+    {:ok, signature} = Bls.sign(privkey, digest)
+    assert Bls.valid?(pubkey, digest, signature)
+  end
 end