hs: Refactor rend_data_t for multi version support

In order to implement proposal 224, we need the data structure rend_data_t to
be able to accomodate versionning that is the current version of hidden
service (2) and the new version (3) and future version.

For that, we implement a series of accessors and a downcast function to get
the v2 data structure. rend_data_t becomes a top level generic place holder.

The entire rend_data_t API has been moved to hs_common.{c|h} in order to
seperate code that is shared from between HS versions and unshared code (in
rendcommon.c).

Closes #19024

Signed-off-by: David Goulet <dgoulet@torproject.org>
Signed-off-by: George Kadianakis <desnacked@riseup.net>

1 files changed, 29 insertions, 118 deletions

diff --git a/src/or/rendcommon.c b/src/or/rendcommon.c
index 01b0766cf0..e6a7bbc28c 100644
--- a/src/or/rendcommon.c
+++ b/src/or/rendcommon.c
@@ -12,6 +12,7 @@
 #include "circuitbuild.h"
 #include "config.h"
 #include "control.h"
+#include "hs_common.h"
 #include "rendclient.h"
 #include "rendcommon.h"
 #include "rendmid.h"
@@ -804,124 +805,6 @@ rend_process_relay_cell(circuit_t *circ, const crypt_path_t *layer_hint,
              command);
 }
 
-/** Allocate and return a new rend_data_t with the same
- * contents as <b>query</b>. */
-rend_data_t *
-rend_data_dup(const rend_data_t *data)
-{
-  rend_data_t *data_dup;
-  tor_assert(data);
-  data_dup = tor_memdup(data, sizeof(rend_data_t));
-  data_dup->hsdirs_fp = smartlist_new();
-  SMARTLIST_FOREACH(data->hsdirs_fp, char *, fp,
-                    smartlist_add(data_dup->hsdirs_fp,
-                                  tor_memdup(fp, DIGEST_LEN)));
-  return data_dup;
-}
-
-/** Compute descriptor ID for each replicas and save them. A valid onion
- * address must be present in the <b>rend_data</b>.
- *
- * Return 0 on success else -1. */
-static int
-compute_desc_id(rend_data_t *rend_data)
-{
-  int ret = 0;
-  unsigned replica;
-  time_t now = time(NULL);
-
-  tor_assert(rend_data);
-
-  /* Compute descriptor ID for each replicas. */
-  for (replica = 0; replica < ARRAY_LENGTH(rend_data->descriptor_id);
-       replica++) {
-    ret = rend_compute_v2_desc_id(rend_data->descriptor_id[replica],
-                                  rend_data->onion_address,
-                                  rend_data->descriptor_cookie,
-                                  now, replica);
-    if (ret < 0) {
-      goto end;
-    }
-  }
-
- end:
-  return ret;
-}
-
-/** Allocate and initialize a rend_data_t object for a service using the
- * given arguments. Only the <b>onion_address</b> is not optional.
- *
- * Return a valid rend_data_t pointer. */
-rend_data_t *
-rend_data_service_create(const char *onion_address, const char *pk_digest,
-                         const uint8_t *cookie, rend_auth_type_t auth_type)
-{
-  rend_data_t *rend_data = tor_malloc_zero(sizeof(*rend_data));
-
-  /* We need at least one else the call is wrong. */
-  tor_assert(onion_address != NULL);
-
-  if (pk_digest) {
-    memcpy(rend_data->rend_pk_digest, pk_digest,
-           sizeof(rend_data->rend_pk_digest));
-  }
-  if (cookie) {
-    memcpy(rend_data->rend_cookie, cookie,
-           sizeof(rend_data->rend_cookie));
-  }
-
-  strlcpy(rend_data->onion_address, onion_address,
-          sizeof(rend_data->onion_address));
-  rend_data->auth_type = auth_type;
-  /* Won't be used but still need to initialize it for rend_data dup and
-   * free. */
-  rend_data->hsdirs_fp = smartlist_new();
-
-  return rend_data;
-}
-
-/** Allocate and initialize a rend_data_t object for a client request using
- * the given arguments.  Either an onion address or a descriptor ID is
- * needed. Both can be given but only the onion address will be used to make
- * the descriptor fetch.
- *
- * Return a valid rend_data_t pointer or NULL on error meaning the
- * descriptor IDs couldn't be computed from the given data. */
-rend_data_t *
-rend_data_client_create(const char *onion_address, const char *desc_id,
-                        const char *cookie, rend_auth_type_t auth_type)
-{
-  rend_data_t *rend_data = tor_malloc_zero(sizeof(*rend_data));
-
-  /* We need at least one else the call is wrong. */
-  tor_assert(onion_address != NULL || desc_id != NULL);
-
-  if (cookie) {
-    memcpy(rend_data->descriptor_cookie, cookie,
-           sizeof(rend_data->descriptor_cookie));
-  }
-  if (desc_id) {
-    memcpy(rend_data->desc_id_fetch, desc_id,
-           sizeof(rend_data->desc_id_fetch));
-  }
-  if (onion_address) {
-    strlcpy(rend_data->onion_address, onion_address,
-            sizeof(rend_data->onion_address));
-    if (compute_desc_id(rend_data) < 0) {
-      goto error;
-    }
-  }
-
-  rend_data->auth_type = auth_type;
-  rend_data->hsdirs_fp = smartlist_new();
-
-  return rend_data;
-
- error:
-  rend_data_free(rend_data);
-  return NULL;
-}
-
 /** Determine the routers that are responsible for <b>id</b> (binary) and
  * add pointers to those routers' routerstatus_t to <b>responsible_dirs</b>.
  * Return -1 if we're returning an empty smartlist, else return 0.
@@ -1067,3 +950,31 @@ rend_auth_decode_cookie(const char *cookie_in, uint8_t *cookie_out,
   return res;
 }
 
+/* Return 1 iff the given <b>digest</b> of a permenanent hidden service key is
+ * equal to the digest in the origin circuit <b>ocirc</b> of its rend data .
+ * If the rend data doesn't exist, 0 is returned. This function is agnostic to
+ * the rend data version. */
+int
+rend_circuit_pk_digest_eq(const origin_circuit_t *ocirc,
+                          const uint8_t *digest)
+{
+  size_t rend_pk_digest_len;
+  const uint8_t *rend_pk_digest;
+
+  tor_assert(ocirc);
+  tor_assert(digest);
+
+  if (ocirc->rend_data == NULL) {
+    goto no_match;
+  }
+
+  rend_pk_digest = rend_data_get_pk_digest(ocirc->rend_data,
+                                           &rend_pk_digest_len);
+  if (tor_memeq(rend_pk_digest, digest, rend_pk_digest_len)) {
+    goto match;
+  }
+ no_match:
+  return 0;
+ match:
+  return 1;
+}