[tor-commits] [tor/master] prop289: Use a 20 bytes digest instead of 4
asn at torproject.org
asn at torproject.org
Thu May 2 15:16:20 UTC 2019
commit 504e05b02999afb6a58ebe4af5770ca8dc136233
Author: David Goulet <dgoulet at torproject.org>
Date: Thu Mar 7 11:20:23 2019 -0500
prop289: Use a 20 bytes digest instead of 4
To achieve such, this commit also changes the trunnel declaration to use a
union instead of a seperate object for the v1 data.
A constant is added for the digest length so we can use it within the SENDME
code giving us a single reference.
Part of #26288
Signed-off-by: David Goulet <dgoulet at torproject.org>
---
src/core/or/sendme.c | 41 ++----
src/test/test_sendme.c | 6 +-
src/trunnel/sendme.c | 349 +++++++++++++--------------------------------
src/trunnel/sendme.h | 107 +++-----------
src/trunnel/sendme.trunnel | 19 +--
5 files changed, 146 insertions(+), 376 deletions(-)
diff --git a/src/core/or/sendme.c b/src/core/or/sendme.c
index 980684c82..a333b02b6 100644
--- a/src/core/or/sendme.c
+++ b/src/core/or/sendme.c
@@ -59,7 +59,8 @@ get_accept_min_version(void)
SENDME_ACCEPT_MIN_VERSION_MAX);
}
-/* Return true iff the given decoded SENDME version 1 cell is valid.
+/* Return true iff the given decoded SENDME version 1 cell is valid and
+ * matches the expected digest on the circuit.
*
* Validation is done by comparing the digest in the cell from the previous
* cell we saw which tells us that the other side has in fact seen that cell.
@@ -67,14 +68,12 @@ get_accept_min_version(void)
static bool
cell_v1_is_valid(const sendme_cell_t *cell, const circuit_t *circ)
{
- sendme_data_v1_t *data = NULL;
+ const uint8_t *cell_digest = NULL;
tor_assert(cell);
+ tor_assert(circ);
- if (sendme_data_v1_parse(&data, sendme_cell_getconstarray_data(cell),
- sendme_cell_getlen_data(cell)) < 0) {
- goto invalid;
- }
+ cell_digest = sendme_cell_getconstarray_data_v1_digest(cell);
/* We shouldn't have received this SENDME if we have no digests. Log at
* protocol warning because it can be tricked by sending many SENDMEs
@@ -94,8 +93,7 @@ cell_v1_is_valid(const sendme_cell_t *cell, const circuit_t *circ)
/* Compare the digest with the one in the SENDME. This cell is invalid
* without a perfect match. */
- if (tor_memcmp(digest, sendme_data_v1_getconstarray_digest(data),
- sendme_data_v1_getlen_digest(data))) {
+ if (tor_memcmp(digest, cell_digest, TRUNNEL_SENDME_V1_DIGEST_LEN)) {
tor_free(digest);
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"SENDME v1 cell digest do not match.");
@@ -105,10 +103,8 @@ cell_v1_is_valid(const sendme_cell_t *cell, const circuit_t *circ)
}
/* Validated SENDME v1 cell. */
- sendme_data_v1_free(data);
return 1;
invalid:
- sendme_data_v1_free(data);
return 0;
}
@@ -213,39 +209,26 @@ build_cell_payload_v1(crypto_digest_t *cell_digest, uint8_t *payload)
{
ssize_t len = -1;
sendme_cell_t *cell = NULL;
- sendme_data_v1_t *data = NULL;
tor_assert(cell_digest);
tor_assert(payload);
cell = sendme_cell_new();
- data = sendme_data_v1_new();
/* Building a payload for version 1. */
sendme_cell_set_version(cell, 0x01);
+ /* Set the data length field for v1. */
+ sendme_cell_set_data_len(cell, TRUNNEL_SENDME_V1_DIGEST_LEN);
/* Copy the digest into the data payload. */
crypto_digest_get_digest(cell_digest,
- (char *) sendme_data_v1_getarray_digest(data),
- sendme_data_v1_getlen_digest(data));
-
- /* Set the length of the data in the cell payload. It is the encoded length
- * of the v1 data object. */
- sendme_cell_setlen_data(cell, sendme_data_v1_encoded_len(data));
- /* Encode into the cell's data field using its current length just set. */
- if (sendme_data_v1_encode(sendme_cell_getarray_data(cell),
- sendme_cell_getlen_data(cell), data) < 0) {
- goto end;
- }
- /* Set the DATA_LEN field to what we've just encoded. */
- sendme_cell_set_data_len(cell, sendme_cell_getlen_data(cell));
+ (char *) sendme_cell_getarray_data_v1_digest(cell),
+ sendme_cell_get_data_len(cell));
/* Finally, encode the cell into the payload. */
len = sendme_cell_encode(payload, RELAY_PAYLOAD_SIZE, cell);
- end:
sendme_cell_free(cell);
- sendme_data_v1_free(data);
return len;
}
@@ -566,9 +549,9 @@ sendme_note_cell_digest(circuit_t *circ)
* recorded. It should never happen in theory as we always record the last
* digest for the v1 SENDME. */
if (TO_OR_CIRCUIT(circ)->crypto.sendme_digest) {
- digest = tor_malloc_zero(4);
+ digest = tor_malloc_zero(TRUNNEL_SENDME_V1_DIGEST_LEN);
crypto_digest_get_digest(TO_OR_CIRCUIT(circ)->crypto.sendme_digest,
- (char *) digest, 4);
+ (char *) digest, TRUNNEL_SENDME_V1_DIGEST_LEN);
if (circ->sendme_last_digests == NULL) {
circ->sendme_last_digests = smartlist_new();
}
diff --git a/src/test/test_sendme.c b/src/test/test_sendme.c
index ad6aac6c0..92f478df0 100644
--- a/src/test/test_sendme.c
+++ b/src/test/test_sendme.c
@@ -156,12 +156,12 @@ test_v1_build_cell(void *arg)
circ = TO_CIRCUIT(or_circ);
cell_digest = crypto_digest_new();
- crypto_digest_add_bytes(cell_digest, "AAAA", 4);
+ crypto_digest_add_bytes(cell_digest, "AAAAAAAAAAAAAAAAAAAA", 20);
tt_assert(cell_digest);
- /* SENDME v1 payload is 7 bytes. See spec. */
+ /* SENDME v1 payload is 3 bytes + 20 bytes digest. See spec. */
ret = build_cell_payload_v1(cell_digest, payload);
- tt_int_op(ret, OP_EQ, 7);
+ tt_int_op(ret, OP_EQ, 23);
/* Validation. */
diff --git a/src/trunnel/sendme.c b/src/trunnel/sendme.c
index 08f9ed5e9..262b91523 100644
--- a/src/trunnel/sendme.c
+++ b/src/trunnel/sendme.c
@@ -43,8 +43,6 @@ static void
sendme_cell_clear(sendme_cell_t *obj)
{
(void) obj;
- TRUNNEL_DYNARRAY_WIPE(&obj->data);
- TRUNNEL_DYNARRAY_CLEAR(&obj->data);
}
void
@@ -84,71 +82,40 @@ sendme_cell_set_data_len(sendme_cell_t *inp, uint16_t val)
return 0;
}
size_t
-sendme_cell_getlen_data(const sendme_cell_t *inp)
+sendme_cell_getlen_data_v1_digest(const sendme_cell_t *inp)
{
- return TRUNNEL_DYNARRAY_LEN(&inp->data);
+ (void)inp; return TRUNNEL_SENDME_V1_DIGEST_LEN;
}
uint8_t
-sendme_cell_get_data(sendme_cell_t *inp, size_t idx)
+sendme_cell_get_data_v1_digest(sendme_cell_t *inp, size_t idx)
{
- return TRUNNEL_DYNARRAY_GET(&inp->data, idx);
+ trunnel_assert(idx < TRUNNEL_SENDME_V1_DIGEST_LEN);
+ return inp->data_v1_digest[idx];
}
uint8_t
-sendme_cell_getconst_data(const sendme_cell_t *inp, size_t idx)
+sendme_cell_getconst_data_v1_digest(const sendme_cell_t *inp, size_t idx)
{
- return sendme_cell_get_data((sendme_cell_t*)inp, idx);
+ return sendme_cell_get_data_v1_digest((sendme_cell_t*)inp, idx);
}
int
-sendme_cell_set_data(sendme_cell_t *inp, size_t idx, uint8_t elt)
+sendme_cell_set_data_v1_digest(sendme_cell_t *inp, size_t idx, uint8_t elt)
{
- TRUNNEL_DYNARRAY_SET(&inp->data, idx, elt);
+ trunnel_assert(idx < TRUNNEL_SENDME_V1_DIGEST_LEN);
+ inp->data_v1_digest[idx] = elt;
return 0;
}
-int
-sendme_cell_add_data(sendme_cell_t *inp, uint8_t elt)
-{
-#if SIZE_MAX >= UINT16_MAX
- if (inp->data.n_ == UINT16_MAX)
- goto trunnel_alloc_failed;
-#endif
- TRUNNEL_DYNARRAY_ADD(uint8_t, &inp->data, elt, {});
- return 0;
- trunnel_alloc_failed:
- TRUNNEL_SET_ERROR_CODE(inp);
- return -1;
-}
uint8_t *
-sendme_cell_getarray_data(sendme_cell_t *inp)
+sendme_cell_getarray_data_v1_digest(sendme_cell_t *inp)
{
- return inp->data.elts_;
+ return inp->data_v1_digest;
}
const uint8_t *
-sendme_cell_getconstarray_data(const sendme_cell_t *inp)
+sendme_cell_getconstarray_data_v1_digest(const sendme_cell_t *inp)
{
- return (const uint8_t *)sendme_cell_getarray_data((sendme_cell_t*)inp);
-}
-int
-sendme_cell_setlen_data(sendme_cell_t *inp, size_t newlen)
-{
- uint8_t *newptr;
-#if UINT16_MAX < SIZE_MAX
- if (newlen > UINT16_MAX)
- goto trunnel_alloc_failed;
-#endif
- newptr = trunnel_dynarray_setlen(&inp->data.allocated_,
- &inp->data.n_, inp->data.elts_, newlen,
- sizeof(inp->data.elts_[0]), (trunnel_free_fn_t) NULL,
- &inp->trunnel_error_code_);
- if (newlen != 0 && newptr == NULL)
- goto trunnel_alloc_failed;
- inp->data.elts_ = newptr;
- return 0;
- trunnel_alloc_failed:
- TRUNNEL_SET_ERROR_CODE(inp);
- return -1;
+ return (const uint8_t *)sendme_cell_getarray_data_v1_digest((sendme_cell_t*)inp);
}
const char *
sendme_cell_check(const sendme_cell_t *obj)
@@ -159,8 +126,18 @@ sendme_cell_check(const sendme_cell_t *obj)
return "A set function failed on this object";
if (! (obj->version == 0 || obj->version == 1))
return "Integer out of bounds";
- if (TRUNNEL_DYNARRAY_LEN(&obj->data) != obj->data_len)
- return "Length mismatch for data";
+ switch (obj->version) {
+
+ case 0:
+ break;
+
+ case 1:
+ break;
+
+ default:
+ return "Bad tag for union";
+ break;
+ }
return NULL;
}
@@ -178,9 +155,21 @@ sendme_cell_encoded_len(const sendme_cell_t *obj)
/* Length of u16 data_len */
result += 2;
+ switch (obj->version) {
- /* Length of u8 data[data_len] */
- result += TRUNNEL_DYNARRAY_LEN(&obj->data);
+ case 0:
+ break;
+
+ case 1:
+
+ /* Length of u8 data_v1_digest[TRUNNEL_SENDME_V1_DIGEST_LEN] */
+ result += TRUNNEL_SENDME_V1_DIGEST_LEN;
+ break;
+
+ default:
+ trunnel_assert(0);
+ break;
+ }
return result;
}
int
@@ -201,6 +190,8 @@ sendme_cell_encode(uint8_t *output, const size_t avail, const sendme_cell_t *obj
const ssize_t encoded_len = sendme_cell_encoded_len(obj);
#endif
+ uint8_t *backptr_data_len = NULL;
+
if (NULL != (msg = sendme_cell_check(obj)))
goto check_failed;
@@ -216,22 +207,43 @@ sendme_cell_encode(uint8_t *output, const size_t avail, const sendme_cell_t *obj
written += 1; ptr += 1;
/* Encode u16 data_len */
+ backptr_data_len = ptr;
trunnel_assert(written <= avail);
if (avail - written < 2)
goto truncated;
trunnel_set_uint16(ptr, trunnel_htons(obj->data_len));
written += 2; ptr += 2;
-
- /* Encode u8 data[data_len] */
{
- size_t elt_len = TRUNNEL_DYNARRAY_LEN(&obj->data);
- trunnel_assert(obj->data_len == elt_len);
+ size_t written_before_union = written;
+
+ /* Encode union data[version] */
trunnel_assert(written <= avail);
- if (avail - written < elt_len)
- goto truncated;
- if (elt_len)
- memcpy(ptr, obj->data.elts_, elt_len);
- written += elt_len; ptr += elt_len;
+ switch (obj->version) {
+
+ case 0:
+ break;
+
+ case 1:
+
+ /* Encode u8 data_v1_digest[TRUNNEL_SENDME_V1_DIGEST_LEN] */
+ trunnel_assert(written <= avail);
+ if (avail - written < TRUNNEL_SENDME_V1_DIGEST_LEN)
+ goto truncated;
+ memcpy(ptr, obj->data_v1_digest, TRUNNEL_SENDME_V1_DIGEST_LEN);
+ written += TRUNNEL_SENDME_V1_DIGEST_LEN; ptr += TRUNNEL_SENDME_V1_DIGEST_LEN;
+ break;
+
+ default:
+ trunnel_assert(0);
+ break;
+ }
+ /* Write the length field back to data_len */
+ trunnel_assert(written >= written_before_union);
+#if UINT16_MAX < SIZE_MAX
+ if (written - written_before_union > UINT16_MAX)
+ goto check_failed;
+#endif
+ trunnel_set_uint16(backptr_data_len, trunnel_htons(written - written_before_union));
}
@@ -279,21 +291,41 @@ sendme_cell_parse_into(sendme_cell_t *obj, const uint8_t *input, const size_t le
CHECK_REMAINING(2, truncated);
obj->data_len = trunnel_ntohs(trunnel_get_uint16(ptr));
remaining -= 2; ptr += 2;
-
- /* Parse u8 data[data_len] */
- CHECK_REMAINING(obj->data_len, truncated);
- TRUNNEL_DYNARRAY_EXPAND(uint8_t, &obj->data, obj->data_len, {});
- obj->data.n_ = obj->data_len;
- if (obj->data_len)
- memcpy(obj->data.elts_, ptr, obj->data_len);
- ptr += obj->data_len; remaining -= obj->data_len;
+ {
+ size_t remaining_after;
+ CHECK_REMAINING(obj->data_len, truncated);
+ remaining_after = remaining - obj->data_len;
+ remaining = obj->data_len;
+
+ /* Parse union data[version] */
+ switch (obj->version) {
+
+ case 0:
+ /* Skip to end of union */
+ ptr += remaining; remaining = 0;
+ break;
+
+ case 1:
+
+ /* Parse u8 data_v1_digest[TRUNNEL_SENDME_V1_DIGEST_LEN] */
+ CHECK_REMAINING(TRUNNEL_SENDME_V1_DIGEST_LEN, fail);
+ memcpy(obj->data_v1_digest, ptr, TRUNNEL_SENDME_V1_DIGEST_LEN);
+ remaining -= TRUNNEL_SENDME_V1_DIGEST_LEN; ptr += TRUNNEL_SENDME_V1_DIGEST_LEN;
+ break;
+
+ default:
+ goto fail;
+ break;
+ }
+ if (remaining != 0)
+ goto fail;
+ remaining = remaining_after;
+ }
trunnel_assert(ptr + remaining == input + len_in);
return len_in - remaining;
truncated:
return -2;
- trunnel_alloc_failed:
- return -1;
fail:
result = -1;
return result;
@@ -313,180 +345,3 @@ sendme_cell_parse(sendme_cell_t **output, const uint8_t *input, const size_t len
}
return result;
}
-sendme_data_v1_t *
-sendme_data_v1_new(void)
-{
- sendme_data_v1_t *val = trunnel_calloc(1, sizeof(sendme_data_v1_t));
- if (NULL == val)
- return NULL;
- return val;
-}
-
-/** Release all storage held inside 'obj', but do not free 'obj'.
- */
-static void
-sendme_data_v1_clear(sendme_data_v1_t *obj)
-{
- (void) obj;
-}
-
-void
-sendme_data_v1_free(sendme_data_v1_t *obj)
-{
- if (obj == NULL)
- return;
- sendme_data_v1_clear(obj);
- trunnel_memwipe(obj, sizeof(sendme_data_v1_t));
- trunnel_free_(obj);
-}
-
-size_t
-sendme_data_v1_getlen_digest(const sendme_data_v1_t *inp)
-{
- (void)inp; return 4;
-}
-
-uint8_t
-sendme_data_v1_get_digest(sendme_data_v1_t *inp, size_t idx)
-{
- trunnel_assert(idx < 4);
- return inp->digest[idx];
-}
-
-uint8_t
-sendme_data_v1_getconst_digest(const sendme_data_v1_t *inp, size_t idx)
-{
- return sendme_data_v1_get_digest((sendme_data_v1_t*)inp, idx);
-}
-int
-sendme_data_v1_set_digest(sendme_data_v1_t *inp, size_t idx, uint8_t elt)
-{
- trunnel_assert(idx < 4);
- inp->digest[idx] = elt;
- return 0;
-}
-
-uint8_t *
-sendme_data_v1_getarray_digest(sendme_data_v1_t *inp)
-{
- return inp->digest;
-}
-const uint8_t *
-sendme_data_v1_getconstarray_digest(const sendme_data_v1_t *inp)
-{
- return (const uint8_t *)sendme_data_v1_getarray_digest((sendme_data_v1_t*)inp);
-}
-const char *
-sendme_data_v1_check(const sendme_data_v1_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
-sendme_data_v1_encoded_len(const sendme_data_v1_t *obj)
-{
- ssize_t result = 0;
-
- if (NULL != sendme_data_v1_check(obj))
- return -1;
-
-
- /* Length of u8 digest[4] */
- result += 4;
- return result;
-}
-int
-sendme_data_v1_clear_errors(sendme_data_v1_t *obj)
-{
- int r = obj->trunnel_error_code_;
- obj->trunnel_error_code_ = 0;
- return r;
-}
-ssize_t
-sendme_data_v1_encode(uint8_t *output, const size_t avail, const sendme_data_v1_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 = sendme_data_v1_encoded_len(obj);
-#endif
-
- if (NULL != (msg = sendme_data_v1_check(obj)))
- goto check_failed;
-
-#ifdef TRUNNEL_CHECK_ENCODED_LEN
- trunnel_assert(encoded_len >= 0);
-#endif
-
- /* Encode u8 digest[4] */
- trunnel_assert(written <= avail);
- if (avail - written < 4)
- goto truncated;
- memcpy(ptr, obj->digest, 4);
- written += 4; ptr += 4;
-
-
- 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 sendme_data_v1_parse(), but do not allocate the output object.
- */
-static ssize_t
-sendme_data_v1_parse_into(sendme_data_v1_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 digest[4] */
- CHECK_REMAINING(4, truncated);
- memcpy(obj->digest, ptr, 4);
- remaining -= 4; ptr += 4;
- trunnel_assert(ptr + remaining == input + len_in);
- return len_in - remaining;
-
- truncated:
- return -2;
-}
-
-ssize_t
-sendme_data_v1_parse(sendme_data_v1_t **output, const uint8_t *input, const size_t len_in)
-{
- ssize_t result;
- *output = sendme_data_v1_new();
- if (NULL == *output)
- return -1;
- result = sendme_data_v1_parse_into(*output, input, len_in);
- if (result < 0) {
- sendme_data_v1_free(*output);
- *output = NULL;
- }
- return result;
-}
diff --git a/src/trunnel/sendme.h b/src/trunnel/sendme.h
index 8207cb56f..f3c3dd78c 100644
--- a/src/trunnel/sendme.h
+++ b/src/trunnel/sendme.h
@@ -8,22 +8,16 @@
#include <stdint.h>
#include "trunnel.h"
+#define TRUNNEL_SENDME_V1_DIGEST_LEN 20
#if !defined(TRUNNEL_OPAQUE) && !defined(TRUNNEL_OPAQUE_SENDME_CELL)
struct sendme_cell_st {
uint8_t version;
uint16_t data_len;
- TRUNNEL_DYNARRAY_HEAD(, uint8_t) data;
+ uint8_t data_v1_digest[TRUNNEL_SENDME_V1_DIGEST_LEN];
uint8_t trunnel_error_code_;
};
#endif
typedef struct sendme_cell_st sendme_cell_t;
-#if !defined(TRUNNEL_OPAQUE) && !defined(TRUNNEL_OPAQUE_SENDME_DATA_V1)
-struct sendme_data_v1_st {
- uint8_t digest[4];
- uint8_t trunnel_error_code_;
-};
-#endif
-typedef struct sendme_data_v1_st sendme_data_v1_t;
/** Return a newly allocated sendme_cell with all elements set to
* zero.
*/
@@ -77,94 +71,31 @@ uint16_t sendme_cell_get_data_len(const sendme_cell_t *inp);
* 'inp' on failure.
*/
int sendme_cell_set_data_len(sendme_cell_t *inp, uint16_t val);
-/** Return the length of the dynamic array holding the data field of
- * the sendme_cell_t in 'inp'.
- */
-size_t sendme_cell_getlen_data(const sendme_cell_t *inp);
-/** Return the element at position 'idx' of the dynamic array field
- * data of the sendme_cell_t in 'inp'.
- */
-uint8_t sendme_cell_get_data(sendme_cell_t *inp, size_t idx);
-/** As sendme_cell_get_data, but take and return a const pointer
- */
-uint8_t sendme_cell_getconst_data(const sendme_cell_t *inp, size_t idx);
-/** Change the element at position 'idx' of the dynamic array field
- * data of the sendme_cell_t in 'inp', so that it will hold the value
- * 'elt'.
- */
-int sendme_cell_set_data(sendme_cell_t *inp, size_t idx, uint8_t elt);
-/** Append a new element 'elt' to the dynamic array field data of the
- * sendme_cell_t in 'inp'.
- */
-int sendme_cell_add_data(sendme_cell_t *inp, uint8_t elt);
-/** Return a pointer to the variable-length array field data of 'inp'.
- */
-uint8_t * sendme_cell_getarray_data(sendme_cell_t *inp);
-/** As sendme_cell_get_data, but take and return a const pointer
- */
-const uint8_t * sendme_cell_getconstarray_data(const sendme_cell_t *inp);
-/** Change the length of the variable-length array field data of 'inp'
- * to 'newlen'.Fill extra elements with 0. Return 0 on success; return
- * -1 and set the error code on 'inp' on failure.
- */
-int sendme_cell_setlen_data(sendme_cell_t *inp, size_t newlen);
-/** Return a newly allocated sendme_data_v1 with all elements set to
- * zero.
- */
-sendme_data_v1_t *sendme_data_v1_new(void);
-/** Release all storage held by the sendme_data_v1 in 'victim'. (Do
- * nothing if 'victim' is NULL.)
- */
-void sendme_data_v1_free(sendme_data_v1_t *victim);
-/** Try to parse a sendme_data_v1 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
- * sendme_data_v1_t. On failure, return -2 if the input appears
- * truncated, and -1 if the input is otherwise invalid.
- */
-ssize_t sendme_data_v1_parse(sendme_data_v1_t **output, const uint8_t *input, const size_t len_in);
-/** Return the number of bytes we expect to need to encode the
- * sendme_data_v1 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 sendme_data_v1_encoded_len(const sendme_data_v1_t *obj);
-/** Try to encode the sendme_data_v1 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 sendme_data_v1_encode(uint8_t *output, size_t avail, const sendme_data_v1_t *input);
-/** Check whether the internal state of the sendme_data_v1 in 'obj' is
- * consistent. Return NULL if it is, and a short message if it is not.
- */
-const char *sendme_data_v1_check(const sendme_data_v1_t *obj);
-/** Clear any errors that were set on the object 'obj' by its setter
- * functions. Return true iff errors were cleared.
- */
-int sendme_data_v1_clear_errors(sendme_data_v1_t *obj);
-/** Return the (constant) length of the array holding the digest field
- * of the sendme_data_v1_t in 'inp'.
+/** Return the (constant) length of the array holding the
+ * data_v1_digest field of the sendme_cell_t in 'inp'.
*/
-size_t sendme_data_v1_getlen_digest(const sendme_data_v1_t *inp);
+size_t sendme_cell_getlen_data_v1_digest(const sendme_cell_t *inp);
/** Return the element at position 'idx' of the fixed array field
- * digest of the sendme_data_v1_t in 'inp'.
+ * data_v1_digest of the sendme_cell_t in 'inp'.
*/
-uint8_t sendme_data_v1_get_digest(sendme_data_v1_t *inp, size_t idx);
-/** As sendme_data_v1_get_digest, but take and return a const pointer
+uint8_t sendme_cell_get_data_v1_digest(sendme_cell_t *inp, size_t idx);
+/** As sendme_cell_get_data_v1_digest, but take and return a const
+ * pointer
*/
-uint8_t sendme_data_v1_getconst_digest(const sendme_data_v1_t *inp, size_t idx);
+uint8_t sendme_cell_getconst_data_v1_digest(const sendme_cell_t *inp, size_t idx);
/** Change the element at position 'idx' of the fixed array field
- * digest of the sendme_data_v1_t in 'inp', so that it will hold the
- * value 'elt'.
+ * data_v1_digest of the sendme_cell_t in 'inp', so that it will hold
+ * the value 'elt'.
*/
-int sendme_data_v1_set_digest(sendme_data_v1_t *inp, size_t idx, uint8_t elt);
-/** Return a pointer to the 4-element array field digest of 'inp'.
+int sendme_cell_set_data_v1_digest(sendme_cell_t *inp, size_t idx, uint8_t elt);
+/** Return a pointer to the TRUNNEL_SENDME_V1_DIGEST_LEN-element array
+ * field data_v1_digest of 'inp'.
*/
-uint8_t * sendme_data_v1_getarray_digest(sendme_data_v1_t *inp);
-/** As sendme_data_v1_get_digest, but take and return a const pointer
+uint8_t * sendme_cell_getarray_data_v1_digest(sendme_cell_t *inp);
+/** As sendme_cell_get_data_v1_digest, but take and return a const
+ * pointer
*/
-const uint8_t * sendme_data_v1_getconstarray_digest(const sendme_data_v1_t *inp);
+const uint8_t * sendme_cell_getconstarray_data_v1_digest(const sendme_cell_t *inp);
#endif
diff --git a/src/trunnel/sendme.trunnel b/src/trunnel/sendme.trunnel
index 7294a09b4..300963e67 100644
--- a/src/trunnel/sendme.trunnel
+++ b/src/trunnel/sendme.trunnel
@@ -1,18 +1,19 @@
/* This file contains the SENDME cell definition. */
+/* v1 digest length in bytes. */
+const TRUNNEL_SENDME_V1_DIGEST_LEN = 20;
+
+/* SENDME cell declaration. */
struct sendme_cell {
/* Version field. */
u8 version IN [0x00, 0x01];
- /* The data content depends on the version. */
+ /* Length of data contained in this cell. */
u16 data_len;
- u8 data[data_len];
-}
-/* SENDME version 0. No data. */
-
-/* SENDME version 1. Authenticated with digest. */
-struct sendme_data_v1 {
- /* A 4 bytes digest. */
- u8 digest[4];
+ /* The data content depends on the version. */
+ union data[version] with length data_len {
+ 0x00: ignore;
+ 0x01: u8 v1_digest[TRUNNEL_SENDME_V1_DIGEST_LEN];
+ };
}
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