test: HS v3 descriptor decoding with client authorization

Signed-off-by: David Goulet <dgoulet@torproject.org>

src/test/hs_test_helpers.c

@@ -226,6 +226,32 @@ hs_helper_desc_equal(const hs_descriptor_t *desc1,
    * encrypted blob. As contrast to the decoding process where we populate a
    * descriptor object. */
 
+  /* Superencrypted data section. */
+  tt_mem_op(desc1->superencrypted_data.auth_ephemeral_pubkey.public_key, OP_EQ,
+            desc2->superencrypted_data.auth_ephemeral_pubkey.public_key,
+            CURVE25519_PUBKEY_LEN);
+
+  /* Auth clients. */
+  {
+    tt_assert(desc1->superencrypted_data.clients);
+    tt_assert(desc2->superencrypted_data.clients);
+    tt_int_op(smartlist_len(desc1->superencrypted_data.clients), ==,
+              smartlist_len(desc2->superencrypted_data.clients));
+    for (int i=0;
+         i < smartlist_len(desc1->superencrypted_data.clients);
+         i++) {
+      hs_desc_authorized_client_t
+        *client1 = smartlist_get(desc1->superencrypted_data.clients, i),
+        *client2 = smartlist_get(desc2->superencrypted_data.clients, i);
+      tor_memeq(client1->client_id, client2->client_id,
+                sizeof(client1->client_id));
+      tor_memeq(client1->iv, client2->iv,
+                sizeof(client1->iv));
+      tor_memeq(client1->encrypted_cookie, client2->encrypted_cookie,
+                sizeof(client1->encrypted_cookie));
+    }
+  }
+
   /* Encrypted data section. */
   tt_uint_op(desc1->encrypted_data.create2_ntor, ==,
              desc2->encrypted_data.create2_ntor);

src/test/test_hs_descriptor.c

@@ -330,6 +330,7 @@ static void
 test_decode_descriptor(void *arg)
 {
   int ret;
+  int i;
   char *encoded = NULL;
   ed25519_keypair_t signing_kp;
   hs_descriptor_t *desc = NULL;
@@ -381,6 +382,75 @@ test_decode_descriptor(void *arg)
     tt_assert(decoded);
   }
 
+  /* Decode a descriptor with auth clients. */
+  {
+    uint8_t descriptor_cookie[HS_DESC_DESCRIPTOR_COOKIE_LEN];
+    curve25519_keypair_t auth_ephemeral_kp;
+    curve25519_keypair_t client_kp, invalid_client_kp;
+    smartlist_t *clients;
+    hs_desc_authorized_client_t *client, *fake_client;
+    client = tor_malloc_zero(sizeof(hs_desc_authorized_client_t));
+
+    /* Prepare all the keys needed to build the auth client. */
+    curve25519_keypair_generate(&auth_ephemeral_kp, 0);
+    curve25519_keypair_generate(&client_kp, 0);
+    curve25519_keypair_generate(&invalid_client_kp, 0);
+    crypto_strongest_rand(descriptor_cookie, HS_DESC_DESCRIPTOR_COOKIE_LEN);
+
+    memcpy(&desc->superencrypted_data.auth_ephemeral_pubkey,
+           &auth_ephemeral_kp.pubkey, CURVE25519_PUBKEY_LEN);
+
+    /* Build and add the auth client to the descriptor. */
+    clients = desc->superencrypted_data.clients;
+    if (!clients) {
+      clients = smartlist_new();
+    }
+    hs_desc_build_authorized_client(&client_kp.pubkey,
+                                    &auth_ephemeral_kp.seckey,
+                                    descriptor_cookie, client);
+    smartlist_add(clients, client);
+
+    /* We need to add fake auth clients here. */
+    for (i=0; i < 15; ++i) {
+      fake_client = tor_malloc_zero(sizeof(hs_desc_authorized_client_t));
+      hs_desc_build_fake_authorized_client(fake_client);
+      smartlist_add(clients, fake_client);
+    }
+    desc->superencrypted_data.clients = clients;
+
+    /* Test the encoding/decoding in the following lines. */
+    hs_helper_get_subcred_from_identity_keypair(&signing_kp,
+                                                subcredential);
+    tor_free(encoded);
+    ret = hs_desc_encode_descriptor(desc, &signing_kp,
+                                    descriptor_cookie, &encoded);
+    tt_int_op(ret, OP_EQ, 0);
+    tt_assert(encoded);
+
+    /* If we do not have the client secret key, the decoding must fail. */
+    hs_descriptor_free(decoded);
+    ret = hs_desc_decode_descriptor(encoded, subcredential,
+                                    NULL, &decoded);
+    tt_int_op(ret, OP_LT, 0);
+    tt_assert(!decoded);
+
+    /* If we have an invalid client secret key, the decoding must fail. */
+    hs_descriptor_free(decoded);
+    ret = hs_desc_decode_descriptor(encoded, subcredential,
+                                    &invalid_client_kp.seckey, &decoded);
+    tt_int_op(ret, OP_LT, 0);
+    tt_assert(!decoded);
+
+    /* If we have the client secret key, the decoding must succeed and the
+     * decoded descriptor must be correct. */
+    ret = hs_desc_decode_descriptor(encoded, subcredential,
+                                    &client_kp.seckey, &decoded);
+    tt_int_op(ret, OP_EQ, 0);
+    tt_assert(decoded);
+
+    hs_helper_desc_equal(desc, decoded);
+  }
+
  done:
   hs_descriptor_free(desc);
   hs_descriptor_free(desc_no_ip);