Fix missing apu/apv IdentityPython/JWTConnect-Python-CryptoJWT#159

src/cryptojwt/jwe/jwe_ec.py

@@ -138,7 +138,7 @@ def dec_setup(self, token, key=None, **kwargs):
             raise Exception("Ephemeral Public Key Missing in ECDH-ES Computation")
 
         epubkey = ECKey(**self.headers["epk"])
-        apu = apv = ""
+        apu = apv = b""
         if "apu" in self.headers:
             apu = b64d(self.headers["apu"].encode())
         if "apv" in self.headers:

tests/test_07_jwe.py

@@ -443,6 +443,28 @@ def test_ecdh_encrypt_decrypt_direct_key():
     assert msg == plain
 
 
+def test_ecdh_encrypt_decrypt_direct_key_wo_apu_apv():
+    # Alice starts of
+    jwenc = JWE_EC(plain, alg="ECDH-ES", enc="A128GCM")
+
+    # Don't supply agreement party information.
+    cek, encrypted_key, iv, params, ret_epk = jwenc.enc_setup(plain, key=eck_bob, apu=b"", apv=b"")
+    # Assert they are not randomized
+    assert params["apv"] == b""
+    assert params["apu"] == b""
+
+    kwargs = {"params": params, "cek": cek, "iv": iv, "encrypted_key": encrypted_key}
+    jwt = jwenc.encrypt(**kwargs)
+
+    # Bob decrypts
+    ret_jwe = factory(jwt, alg="ECDH-ES", enc="A128GCM")
+    jwdec = JWE_EC()
+    jwdec.dec_setup(ret_jwe.jwt, key=bob)
+    msg = jwdec.decrypt(ret_jwe.jwt)
+
+    assert msg == plain
+
+
 def test_ecdh_encrypt_decrypt_keywrapped_key():
     jwenc = JWE_EC(plain, alg="ECDH-ES+A128KW", enc="A128GCM")
     cek, encrypted_key, iv, params, ret_epk = jwenc.enc_setup(plain, key=eck_bob)