trunnel: Add RENDEZVOUS2 cell definition

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

3 files changed, 259 insertions, 1 deletions

diff --git a/src/trunnel/hs/cell_rendezvous.c b/src/trunnel/hs/cell_rendezvous.c
index e961cd09d4..e4d3244bd1 100644
--- a/src/trunnel/hs/cell_rendezvous.c
+++ b/src/trunnel/hs/cell_rendezvous.c
@@ -290,3 +290,181 @@ trn_cell_rendezvous1_parse(trn_cell_rendezvous1_t **output, const uint8_t *input
   }
   return result;
 }
+trn_cell_rendezvous2_t *
+trn_cell_rendezvous2_new(void)
+{
+  trn_cell_rendezvous2_t *val = trunnel_calloc(1, sizeof(trn_cell_rendezvous2_t));
+  if (NULL == val)
+    return NULL;
+  return val;
+}
+
+/** Release all storage held inside 'obj', but do not free 'obj'.
+ */
+static void
+trn_cell_rendezvous2_clear(trn_cell_rendezvous2_t *obj)
+{
+  (void) obj;
+}
+
+void
+trn_cell_rendezvous2_free(trn_cell_rendezvous2_t *obj)
+{
+  if (obj == NULL)
+    return;
+  trn_cell_rendezvous2_clear(obj);
+  trunnel_memwipe(obj, sizeof(trn_cell_rendezvous2_t));
+  trunnel_free_(obj);
+}
+
+size_t
+trn_cell_rendezvous2_getlen_handshake_info(const trn_cell_rendezvous2_t *inp)
+{
+  (void)inp;  return TRUNNEL_HANDSHAKE_INFO_LEN;
+}
+
+uint8_t
+trn_cell_rendezvous2_get_handshake_info(trn_cell_rendezvous2_t *inp, size_t idx)
+{
+  trunnel_assert(idx < TRUNNEL_HANDSHAKE_INFO_LEN);
+  return inp->handshake_info[idx];
+}
+
+uint8_t
+trn_cell_rendezvous2_getconst_handshake_info(const trn_cell_rendezvous2_t *inp, size_t idx)
+{
+  return trn_cell_rendezvous2_get_handshake_info((trn_cell_rendezvous2_t*)inp, idx);
+}
+int
+trn_cell_rendezvous2_set_handshake_info(trn_cell_rendezvous2_t *inp, size_t idx, uint8_t elt)
+{
+  trunnel_assert(idx < TRUNNEL_HANDSHAKE_INFO_LEN);
+  inp->handshake_info[idx] = elt;
+  return 0;
+}
+
+uint8_t *
+trn_cell_rendezvous2_getarray_handshake_info(trn_cell_rendezvous2_t *inp)
+{
+  return inp->handshake_info;
+}
+const uint8_t  *
+trn_cell_rendezvous2_getconstarray_handshake_info(const trn_cell_rendezvous2_t *inp)
+{
+  return (const uint8_t  *)trn_cell_rendezvous2_getarray_handshake_info((trn_cell_rendezvous2_t*)inp);
+}
+const char *
+trn_cell_rendezvous2_check(const trn_cell_rendezvous2_t *obj)
+{
+  if (obj == NULL)
+    return "Object was NULL";
+  if (obj->trunnel_error_code_)
+    return "A set function failed on this object";
+  return NULL;
+}
+
+ssize_t
+trn_cell_rendezvous2_encoded_len(const trn_cell_rendezvous2_t *obj)
+{
+  ssize_t result = 0;
+
+  if (NULL != trn_cell_rendezvous2_check(obj))
+     return -1;
+
+
+  /* Length of u8 handshake_info[TRUNNEL_HANDSHAKE_INFO_LEN] */
+  result += TRUNNEL_HANDSHAKE_INFO_LEN;
+  return result;
+}
+int
+trn_cell_rendezvous2_clear_errors(trn_cell_rendezvous2_t *obj)
+{
+  int r = obj->trunnel_error_code_;
+  obj->trunnel_error_code_ = 0;
+  return r;
+}
+ssize_t
+trn_cell_rendezvous2_encode(uint8_t *output, const size_t avail, const trn_cell_rendezvous2_t *obj)
+{
+  ssize_t result = 0;
+  size_t written = 0;
+  uint8_t *ptr = output;
+  const char *msg;
+#ifdef TRUNNEL_CHECK_ENCODED_LEN
+  const ssize_t encoded_len = trn_cell_rendezvous2_encoded_len(obj);
+#endif
+
+  if (NULL != (msg = trn_cell_rendezvous2_check(obj)))
+    goto check_failed;
+
+#ifdef TRUNNEL_CHECK_ENCODED_LEN
+  trunnel_assert(encoded_len >= 0);
+#endif
+
+  /* Encode u8 handshake_info[TRUNNEL_HANDSHAKE_INFO_LEN] */
+  trunnel_assert(written <= avail);
+  if (avail - written < TRUNNEL_HANDSHAKE_INFO_LEN)
+    goto truncated;
+  memcpy(ptr, obj->handshake_info, TRUNNEL_HANDSHAKE_INFO_LEN);
+  written += TRUNNEL_HANDSHAKE_INFO_LEN; ptr += TRUNNEL_HANDSHAKE_INFO_LEN;
+
+
+  trunnel_assert(ptr == output + written);
+#ifdef TRUNNEL_CHECK_ENCODED_LEN
+  {
+    trunnel_assert(encoded_len >= 0);
+    trunnel_assert((size_t)encoded_len == written);
+  }
+
+#endif
+
+  return written;
+
+ truncated:
+  result = -2;
+  goto fail;
+ check_failed:
+  (void)msg;
+  result = -1;
+  goto fail;
+ fail:
+  trunnel_assert(result < 0);
+  return result;
+}
+
+/** As trn_cell_rendezvous2_parse(), but do not allocate the output
+ * object.
+ */
+static ssize_t
+trn_cell_rendezvous2_parse_into(trn_cell_rendezvous2_t *obj, const uint8_t *input, const size_t len_in)
+{
+  const uint8_t *ptr = input;
+  size_t remaining = len_in;
+  ssize_t result = 0;
+  (void)result;
+
+  /* Parse u8 handshake_info[TRUNNEL_HANDSHAKE_INFO_LEN] */
+  CHECK_REMAINING(TRUNNEL_HANDSHAKE_INFO_LEN, truncated);
+  memcpy(obj->handshake_info, ptr, TRUNNEL_HANDSHAKE_INFO_LEN);
+  remaining -= TRUNNEL_HANDSHAKE_INFO_LEN; ptr += TRUNNEL_HANDSHAKE_INFO_LEN;
+  trunnel_assert(ptr + remaining == input + len_in);
+  return len_in - remaining;
+
+ truncated:
+  return -2;
+}
+
+ssize_t
+trn_cell_rendezvous2_parse(trn_cell_rendezvous2_t **output, const uint8_t *input, const size_t len_in)
+{
+  ssize_t result;
+  *output = trn_cell_rendezvous2_new();
+  if (NULL == *output)
+    return -1;
+  result = trn_cell_rendezvous2_parse_into(*output, input, len_in);
+  if (result < 0) {
+    trn_cell_rendezvous2_free(*output);
+    *output = NULL;
+  }
+  return result;
+}
diff --git a/src/trunnel/hs/cell_rendezvous.h b/src/trunnel/hs/cell_rendezvous.h
index 2387d77f4f..5dcc6539b6 100644
--- a/src/trunnel/hs/cell_rendezvous.h
+++ b/src/trunnel/hs/cell_rendezvous.h
@@ -9,6 +9,7 @@
 #include "trunnel.h"
 
 #define TRUNNEL_REND_COOKIE_LEN 20
+#define TRUNNEL_HANDSHAKE_INFO_LEN 64
 #if !defined(TRUNNEL_OPAQUE) && !defined(TRUNNEL_OPAQUE_TRN_CELL_RENDEZVOUS1)
 struct trn_cell_rendezvous1_st {
   uint8_t rendezvous_cookie[TRUNNEL_REND_COOKIE_LEN];
@@ -17,6 +18,13 @@ struct trn_cell_rendezvous1_st {
 };
 #endif
 typedef struct trn_cell_rendezvous1_st trn_cell_rendezvous1_t;
+#if !defined(TRUNNEL_OPAQUE) && !defined(TRUNNEL_OPAQUE_TRN_CELL_RENDEZVOUS2)
+struct trn_cell_rendezvous2_st {
+  uint8_t handshake_info[TRUNNEL_HANDSHAKE_INFO_LEN];
+  uint8_t trunnel_error_code_;
+};
+#endif
+typedef struct trn_cell_rendezvous2_st trn_cell_rendezvous2_t;
 /** Return a newly allocated trn_cell_rendezvous1 with all elements
  * set to zero.
  */
@@ -113,6 +121,67 @@ const uint8_t  * trn_cell_rendezvous1_getconstarray_handshake_info(const trn_cel
  * failure.
  */
 int trn_cell_rendezvous1_setlen_handshake_info(trn_cell_rendezvous1_t *inp, size_t newlen);
+/** Return a newly allocated trn_cell_rendezvous2 with all elements
+ * set to zero.
+ */
+trn_cell_rendezvous2_t *trn_cell_rendezvous2_new(void);
+/** Release all storage held by the trn_cell_rendezvous2 in 'victim'.
+ * (Do nothing if 'victim' is NULL.)
+ */
+void trn_cell_rendezvous2_free(trn_cell_rendezvous2_t *victim);
+/** Try to parse a trn_cell_rendezvous2 from the buffer in 'input',
+ * using up to 'len_in' bytes from the input buffer. On success,
+ * return the number of bytes consumed and set *output to the newly
+ * allocated trn_cell_rendezvous2_t. On failure, return -2 if the
+ * input appears truncated, and -1 if the input is otherwise invalid.
+ */
+ssize_t trn_cell_rendezvous2_parse(trn_cell_rendezvous2_t **output, const uint8_t *input, const size_t len_in);
+/** Return the number of bytes we expect to need to encode the
+ * trn_cell_rendezvous2 in 'obj'. On failure, return a negative value.
+ * Note that this value may be an overestimate, and can even be an
+ * underestimate for certain unencodeable objects.
+ */
+ssize_t trn_cell_rendezvous2_encoded_len(const trn_cell_rendezvous2_t *obj);
+/** Try to encode the trn_cell_rendezvous2 from 'input' into the
+ * buffer at 'output', using up to 'avail' bytes of the output buffer.
+ * On success, return the number of bytes used. On failure, return -2
+ * if the buffer was not long enough, and -1 if the input was invalid.
+ */
+ssize_t trn_cell_rendezvous2_encode(uint8_t *output, size_t avail, const trn_cell_rendezvous2_t *input);
+/** Check whether the internal state of the trn_cell_rendezvous2 in
+ * 'obj' is consistent. Return NULL if it is, and a short message if
+ * it is not.
+ */
+const char *trn_cell_rendezvous2_check(const trn_cell_rendezvous2_t *obj);
+/** Clear any errors that were set on the object 'obj' by its setter
+ * functions. Return true iff errors were cleared.
+ */
+int trn_cell_rendezvous2_clear_errors(trn_cell_rendezvous2_t *obj);
+/** Return the (constant) length of the array holding the
+ * handshake_info field of the trn_cell_rendezvous2_t in 'inp'.
+ */
+size_t trn_cell_rendezvous2_getlen_handshake_info(const trn_cell_rendezvous2_t *inp);
+/** Return the element at position 'idx' of the fixed array field
+ * handshake_info of the trn_cell_rendezvous2_t in 'inp'.
+ */
+uint8_t trn_cell_rendezvous2_get_handshake_info(trn_cell_rendezvous2_t *inp, size_t idx);
+/** As trn_cell_rendezvous2_get_handshake_info, but take and return a
+ * const pointer
+ */
+uint8_t trn_cell_rendezvous2_getconst_handshake_info(const trn_cell_rendezvous2_t *inp, size_t idx);
+/** Change the element at position 'idx' of the fixed array field
+ * handshake_info of the trn_cell_rendezvous2_t in 'inp', so that it
+ * will hold the value 'elt'.
+ */
+int trn_cell_rendezvous2_set_handshake_info(trn_cell_rendezvous2_t *inp, size_t idx, uint8_t elt);
+/** Return a pointer to the TRUNNEL_HANDSHAKE_INFO_LEN-element array
+ * field handshake_info of 'inp'.
+ */
+uint8_t * trn_cell_rendezvous2_getarray_handshake_info(trn_cell_rendezvous2_t *inp);
+/** As trn_cell_rendezvous2_get_handshake_info, but take and return a
+ * const pointer
+ */
+const uint8_t  * trn_cell_rendezvous2_getconstarray_handshake_info(const trn_cell_rendezvous2_t *inp);
 
 
 #endif
diff --git a/src/trunnel/hs/cell_rendezvous.trunnel b/src/trunnel/hs/cell_rendezvous.trunnel
index 27f1728b4a..2128b4d126 100644
--- a/src/trunnel/hs/cell_rendezvous.trunnel
+++ b/src/trunnel/hs/cell_rendezvous.trunnel
@@ -1,11 +1,16 @@
 /*
- * This contains the definition of the RENDEZVOUS1 cell for onion service
+ * This contains the definition of the RENDEZVOUS1/2 cell for onion service
  * version 3 and onward. The following format is specified in proposal 224
  * section 4.2.
  */
 
 /* Rendezvous cookie length. */
 const TRUNNEL_REND_COOKIE_LEN = 20;
+/* The HANDSHAKE_INFO field layout is as follow:
+ *    SERVER_PK   [PK_PUBKEY_LEN bytes]
+ *    AUTH        [MAC_LEN bytes]
+ * This means, the size is 32 bytes + 32 bytes. */
+const TRUNNEL_HANDSHAKE_INFO_LEN = 64;
 
 /* RENDEZVOUS1 payload. See details in section 4.2. */
 struct trn_cell_rendezvous1 {
@@ -16,3 +21,9 @@ struct trn_cell_rendezvous1 {
    * handshake type used. */
   u8 handshake_info[];
 };
+
+/* RENDEZVOUS2 payload. See details in section 4.2. */
+struct trn_cell_rendezvous2 {
+  /* The HANDSHAKE_INFO field. */
+  u8 handshake_info[TRUNNEL_HANDSHAKE_INFO_LEN];
+};