cpp-jwt: ES256/384 signature verification fails

Starting from this test, I’m trying to get my stuff working. However, I failed at verifying the signature from the tests as a starting example. Something is wrong. I need ECC because it’s more efficient than RSA. In this test that I got from the code:

TEST (ESAlgo, ES384EncodingDecodingTest)
{
  using namespace jwt::params;

  std::string key = read_from_file(EC384_PRIV_KEY);
  ASSERT_TRUE (key.length());

  jwt::jwt_object obj{algorithm("ES384"), secret(key)};

  obj.add_claim("iss", "arun.muralidharan")
     .add_claim("aud", "all")
     .add_claim("exp", 1513862371)
     ;

  auto enc_str = obj.signature();

  key = read_from_file(EC384_PUB_KEY);
  ASSERT_TRUE (key.length());

  auto dec_obj = jwt::decode(enc_str, algorithms({"es384"}), verify(false), secret(key));

  EXPECT_EQ (dec_obj.header().algo(), jwt::algorithm::ES384);

  std::cout << enc_str << std::endl;

}

I added that cout statement, then went to jwt.io, and it fails at verifying the signature. Something is wrong there.

I also tried using my own key that I generated in OpenSSL using:

CURVE=secp384r1
openssl ecparam -name ${CURVE} -out curve.pem
openssl ecparam -name ${CURVE} -genkey -noout -out privkey.pem
openssl ec -in privkey.pem -pubout -out pubkey.pem

But my key fails too. Also 256 bit fail the same.

Unfortunately the library is not usable in this state. Can you please take a look and see why this is happening?