trunnel: Move ESTABLISH_INTRO cell sig_len after the end_sig_fields

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

src/trunnel/hs/cell_establish_intro.c

@@ -231,6 +231,11 @@ hs_cell_establish_intro_getconstarray_handshake_mac(const hs_cell_establish_intr
 {
   return (const uint8_t  *)hs_cell_establish_intro_getarray_handshake_mac((hs_cell_establish_intro_t*)inp);
 }
+const uint8_t *
+hs_cell_establish_intro_get_end_sig_fields(const hs_cell_establish_intro_t *inp)
+{
+  return inp->end_sig_fields;
+}
 uint16_t
 hs_cell_establish_intro_get_sig_len(const hs_cell_establish_intro_t *inp)
 {
@@ -242,11 +247,6 @@ hs_cell_establish_intro_set_sig_len(hs_cell_establish_intro_t *inp, uint16_t val
   inp->sig_len = val;
   return 0;
 }
-const uint8_t *
-hs_cell_establish_intro_get_end_sig_fields(const hs_cell_establish_intro_t *inp)
-{
-  return inp->end_sig_fields;
-}
 size_t
 hs_cell_establish_intro_getlen_sig(const hs_cell_establish_intro_t *inp)
 {
@@ -518,12 +518,12 @@ hs_cell_establish_intro_parse_into(hs_cell_establish_intro_t *obj, const uint8_t
   CHECK_REMAINING(TRUNNEL_SHA3_256_LEN, truncated);
   memcpy(obj->handshake_mac, ptr, TRUNNEL_SHA3_256_LEN);
   remaining -= TRUNNEL_SHA3_256_LEN; ptr += TRUNNEL_SHA3_256_LEN;
+  obj->end_sig_fields = ptr;
 
   /* Parse u16 sig_len */
   CHECK_REMAINING(2, truncated);
   obj->sig_len = trunnel_ntohs(trunnel_get_uint16(ptr));
   remaining -= 2; ptr += 2;
-  obj->end_sig_fields = ptr;
 
   /* Parse u8 sig[sig_len] */
   CHECK_REMAINING(obj->sig_len, truncated);

src/trunnel/hs/cell_establish_intro.h

@@ -19,8 +19,8 @@ struct hs_cell_establish_intro_st {
   struct cell_extension_st *extensions;
   const uint8_t *end_mac_fields;
   uint8_t handshake_mac[TRUNNEL_SHA3_256_LEN];
-  uint16_t sig_len;
   const uint8_t *end_sig_fields;
+  uint16_t sig_len;
   TRUNNEL_DYNARRAY_HEAD(, uint8_t) sig;
   uint8_t trunnel_error_code_;
 };
@@ -170,6 +170,9 @@ uint8_t * hs_cell_establish_intro_getarray_handshake_mac(hs_cell_establish_intro
  * a const pointer
  */
 const uint8_t  * hs_cell_establish_intro_getconstarray_handshake_mac(const hs_cell_establish_intro_t *inp);
+/** Return the position for end_sig_fields when we parsed this object
+ */
+const uint8_t * hs_cell_establish_intro_get_end_sig_fields(const hs_cell_establish_intro_t *inp);
 /** Return the value of the sig_len field of the
  * hs_cell_establish_intro_t in 'inp'
  */
@@ -179,9 +182,6 @@ uint16_t hs_cell_establish_intro_get_sig_len(const hs_cell_establish_intro_t *in
  * return -1 and set the error code on 'inp' on failure.
  */
 int hs_cell_establish_intro_set_sig_len(hs_cell_establish_intro_t *inp, uint16_t val);
-/** Return the position for end_sig_fields when we parsed this object
- */
-const uint8_t * hs_cell_establish_intro_get_end_sig_fields(const hs_cell_establish_intro_t *inp);
 /** Return the length of the dynamic array holding the sig field of
  * the hs_cell_establish_intro_t in 'inp'.
  */

src/trunnel/hs/cell_establish_intro.trunnel

@@ -26,9 +26,9 @@ struct hs_cell_establish_intro {
   u8 handshake_mac[TRUNNEL_SHA3_256_LEN];
 
   /* Signature */
-  u16 sig_len;
   /* Indicate the end of the handshake authentication data. */
   @ptr end_sig_fields;
+  u16 sig_len;
   u8 sig[sig_len];
 };