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Rename handshake_digest to rend_circ_nonce

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The handshake_digest field was never meaningfully a digest *of* the
handshake, but rather is a digest *from* the handshake that we exapted
to prevent replays of ESTABLISH_INTRO cells.  The ntor handshake will
generate it as more key material rather than taking it from any part
of the circuit handshake reply..
This commit is contained in:
Nick Mathewson 2012-12-04 21:39:54 -05:00
parent f58d4dfcd6
commit 18c7d3f157
4 changed files with 11 additions and 12 deletions
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6
src/or/circuitbuild.c
View File

@ -1409,7 +1409,7 @@ circuit_finish_handshake(origin_circuit_t *circ, uint8_t reply_type,
&hop->handshake_state,
reply,
(uint8_t*)keys, sizeof(keys),
(uint8_t*)hop->handshake_digest) < 0) {
(uint8_t*)hop->rend_circ_nonce) < 0) {
log_warn(LD_CIRC,"onion_skin_client_handshake failed.");
return -END_CIRC_REASON_TORPROTOCOL;
}
@ -1517,9 +1517,9 @@ onionskin_answer(or_circuit_t *circ, uint8_t cell_type, const char *payload,
/* XXXX Move responsibility for extracting this. */
if (cell_type == CELL_CREATED)
memcpy(circ->handshake_digest, cell.payload+DH_KEY_LEN, DIGEST_LEN);
memcpy(circ->rend_circ_nonce, cell.payload+DH_KEY_LEN, DIGEST_LEN);
else
memcpy(circ->handshake_digest, cell.payload+DIGEST_LEN, DIGEST_LEN);
memcpy(circ->rend_circ_nonce, cell.payload+DIGEST_LEN, DIGEST_LEN);
circ->is_first_hop = (cell_type == CELL_CREATED_FAST);

7
src/or/or.h
View File

@ -2568,8 +2568,7 @@ typedef struct crypt_path_t {
crypto_dh_t *rend_dh_handshake_state;
/** Negotiated key material shared with the OR at this step. */
/* XXXX RENAME */
char handshake_digest[DIGEST_LEN];/* KH in tor-spec.txt */
char rend_circ_nonce[DIGEST_LEN];/* KH in tor-spec.txt */
/** Information to extend to the OR at this step. */
extend_info_t *extend_info;
@ -2978,8 +2977,8 @@ typedef struct or_circuit_t {
char rend_token[REND_TOKEN_LEN];
/* ???? move to a subtype or adjunct structure? Wastes 20 bytes -NM */
/* XXXX rename this. */
char handshake_digest[DIGEST_LEN]; /**< Stores KH for the handshake. */
/** Stores KH for the handshake. */
char rend_circ_nonce[DIGEST_LEN];/* KH in tor-spec.txt */
/** How many more relay_early cells can we send on this circuit, according
* to the specification? */

4
src/or/rendmid.c
View File

@ -56,8 +56,8 @@ rend_mid_establish_intro(or_circuit_t *circ, const uint8_t *request,
goto err;
}
/* Next 20 bytes: Hash of handshake_digest | "INTRODUCE" */
memcpy(buf, circ->handshake_digest, DIGEST_LEN);
/* Next 20 bytes: Hash of rend_circ_nonce | "INTRODUCE" */
memcpy(buf, circ->rend_circ_nonce, DIGEST_LEN);
memcpy(buf+DIGEST_LEN, "INTRODUCE", 9);
if (crypto_digest(expected_digest, buf, DIGEST_LEN+9) < 0) {
log_warn(LD_BUG, "Internal error computing digest.");

6
src/or/rendservice.c
View File

@ -1382,7 +1382,7 @@ rend_service_introduce(origin_circuit_t *circuit, const uint8_t *request,
dh = NULL;
if (circuit_init_cpath_crypto(cpath,keys+DIGEST_LEN,1)<0)
goto err;
memcpy(cpath->handshake_digest, keys, DIGEST_LEN);
memcpy(cpath->rend_circ_nonce, keys, DIGEST_LEN);
goto done;
@ -2483,7 +2483,7 @@ rend_service_intro_has_opened(origin_circuit_t *circuit)
len = r;
set_uint16(buf, htons((uint16_t)len));
len += 2;
memcpy(auth, circuit->cpath->prev->handshake_digest, DIGEST_LEN);
memcpy(auth, circuit->cpath->prev->rend_circ_nonce, DIGEST_LEN);
memcpy(auth+DIGEST_LEN, "INTRODUCE", 9);
if (crypto_digest(buf+len, auth, DIGEST_LEN+9))
goto err;
@ -2630,7 +2630,7 @@ rend_service_rendezvous_has_opened(origin_circuit_t *circuit)
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
memcpy(buf+REND_COOKIE_LEN+DH_KEY_LEN, hop->handshake_digest,
memcpy(buf+REND_COOKIE_LEN+DH_KEY_LEN, hop->rend_circ_nonce,
DIGEST_LEN);
/* Send the cell */