Implement proposal 228: cross-certification with onion keys

Routers now use TAP and ntor onion keys to sign their identity keys,
and put these signatures in their descriptors.  That allows other
parties to be confident that the onion keys are indeed controlled by
the router that generated the descriptor.

1 files changed, 70 insertions, 0 deletions

diff --git a/src/test/test_routerkeys.c b/src/test/test_routerkeys.c
index 8780213a29..2434255b63 100644
--- a/src/test/test_routerkeys.c
+++ b/src/test/test_routerkeys.c
@@ -514,6 +514,74 @@ test_routerkeys_ed_keys_init_all(void *arg)
   routerkeys_free_all();
 }
 
+static void
+test_routerkeys_cross_certify_ntor(void *args)
+{
+  (void) args;
+
+  tor_cert_t *cert = NULL;
+  curve25519_keypair_t onion_keys;
+  ed25519_public_key_t master_key;
+  ed25519_public_key_t onion_check_key;
+  time_t now = time(NULL);
+  int sign;
+
+  tt_int_op(0, ==, ed25519_public_from_base64(&master_key,
+                               "IamwritingthesetestsOnARainyAfternoonin2014"));
+  tt_int_op(0, ==, curve25519_keypair_generate(&onion_keys, 0));
+  cert = make_ntor_onion_key_crosscert(&onion_keys,
+                                       &master_key,
+                                       now, 10000,
+                                       &sign);
+  tt_assert(cert);
+  tt_assert(sign == 0 || sign == 1);
+  tt_int_op(cert->cert_type, ==, CERT_TYPE_ONION_ID);
+  tt_int_op(1, ==, ed25519_pubkey_eq(&cert->signed_key, &master_key));
+  tt_int_op(0, ==, ed25519_public_key_from_curve25519_public_key(
+                               &onion_check_key, &onion_keys.pubkey, sign));
+  tt_int_op(0, ==, tor_cert_checksig(cert, &onion_check_key, now));
+
+ done:
+  tor_cert_free(cert);
+}
+
+static void
+test_routerkeys_cross_certify_tap(void *args)
+{
+  (void)args;
+  uint8_t *cc = NULL;
+  int cc_len;
+  ed25519_public_key_t master_key;
+  crypto_pk_t *onion_key = pk_generate(2), *id_key = pk_generate(1);
+  char digest[20];
+  char buf[128];
+  int n;
+
+  tt_int_op(0, ==, ed25519_public_from_base64(&master_key,
+                               "IAlreadyWroteTestsForRouterdescsUsingTheseX"));
+
+  cc = make_tap_onion_key_crosscert(onion_key,
+                                    &master_key,
+                                    id_key, &cc_len);
+  tt_assert(cc);
+  tt_assert(cc_len);
+
+  n = crypto_pk_public_checksig(onion_key, buf, sizeof(buf),
+                                (char*)cc, cc_len);
+  tt_int_op(n,>,0);
+  tt_int_op(n,==,52);
+
+  crypto_pk_get_digest(id_key, digest);
+  tt_mem_op(buf,==,digest,20);
+  tt_mem_op(buf+20,==,master_key.pubkey,32);
+
+  tt_int_op(0, ==, check_tap_onion_key_crosscert(cc, cc_len,
+                                    onion_key, &master_key, (uint8_t*)digest));
+
+ done:
+  tor_free(cc);
+}
+
 #define TEST(name, flags)                                       \
   { #name , test_routerkeys_ ## name, (flags), NULL, NULL }
 
@@ -524,6 +592,8 @@ struct testcase_t routerkeys_tests[] = {
   TEST(ed_key_init_basic, TT_FORK),
   TEST(ed_key_init_split, TT_FORK),
   TEST(ed_keys_init_all, TT_FORK),
+  TEST(cross_certify_ntor, 0),
+  TEST(cross_certify_tap, 0),
   END_OF_TESTCASES
 };