From 94c458d11dc2322a3e90eebbbe9a123220440a69 Mon Sep 17 00:00:00 2001 From: Florian Dold Date: Fri, 11 Dec 2015 19:19:47 +0000 Subject: Proper salting for set union. --- src/set/gnunet-service-set_protocol.h | 21 ++++++++ src/set/gnunet-service-set_union.c | 90 ++++++++++++++++++++++++++--------- 2 files changed, 88 insertions(+), 23 deletions(-) diff --git a/src/set/gnunet-service-set_protocol.h b/src/set/gnunet-service-set_protocol.h index eee0dc5ae..b96ea0889 100644 --- a/src/set/gnunet-service-set_protocol.h +++ b/src/set/gnunet-service-set_protocol.h @@ -96,6 +96,27 @@ struct IBFMessage }; +struct InquiryMessage +{ + /** + * Type: #GNUNET_MESSAGE_TYPE_SET_UNION_P2P_IBF + */ + struct GNUNET_MessageHeader header; + + /** + * Salt used when hashing elements for this inquiry. + */ + uint32_t salt GNUNET_PACKED; + + /** + * Reserved, set to 0. + */ + uint32_t reserved GNUNET_PACKED; + + /* rest: inquiry IBF keys */ +}; + + /** * During intersection, the first (and possibly second) message * send it the number of elements in the set, to allow the peers diff --git a/src/set/gnunet-service-set_union.c b/src/set/gnunet-service-set_union.c index 4cba00eb0..c8f3ba24b 100644 --- a/src/set/gnunet-service-set_union.c +++ b/src/set/gnunet-service-set_union.c @@ -172,6 +172,16 @@ struct OperationState * Hashes for elements that we have demanded from the other peer. */ struct GNUNET_CONTAINER_MultiHashMap *demanded_hashes; + + /** + * Salt that we're using for sending IBFs + */ + uint32_t salt_send; + + /** + * Salt for the IBF we've received and that we're currently decoding. + */ + uint32_t salt_receive; }; @@ -334,18 +344,13 @@ fail_union_operation (struct Operation *op) * a salt. * * @param src the hash code - * @param salt salt to use * @return the derived IBF key */ static struct IBF_Key -get_ibf_key (const struct GNUNET_HashCode *src, - uint16_t salt) +get_ibf_key (const struct GNUNET_HashCode *src) { struct IBF_Key key; - - /* FIXME: Ensure that the salt is handled correctly. - This is a quick fix so that consensus works for now. */ - salt = 0; + uint16_t salt = 0; GNUNET_CRYPTO_kdf (&key, sizeof (key), src, sizeof *src, @@ -396,7 +401,7 @@ op_has_element (struct Operation *op, int ret; struct IBF_Key ibf_key; - ibf_key = get_ibf_key (element_hash, op->spec->salt); + ibf_key = get_ibf_key (element_hash); ret = GNUNET_CONTAINER_multihashmap32_get_multiple (op->state->key_to_element, (uint32_t) ibf_key.key_val, op_has_element_iterator, @@ -429,7 +434,7 @@ op_register_element (struct Operation *op, struct IBF_Key ibf_key; struct KeyEntry *k; - ibf_key = get_ibf_key (&ee->element_hash, op->spec->salt); + ibf_key = get_ibf_key (&ee->element_hash); k = GNUNET_new (struct KeyEntry); k->element = ee; k->ibf_key = ibf_key; @@ -441,6 +446,30 @@ op_register_element (struct Operation *op, } +static void +salt_key (const struct IBF_Key *k_in, + uint32_t salt, + struct IBF_Key *k_out) +{ + int s = salt % 64; + uint64_t x = k_in->key_val; + x = (x >> s) | (x << (64 - s)); + k_out->key_val = x; +} + + +static void +unsalt_key (const struct IBF_Key *k_in, + uint32_t salt, + struct IBF_Key *k_out) +{ + int s = -(salt % 64); + uint64_t x = k_in->key_val; + x = (x >> s) | (x << (64 - s)); + k_out->key_val = x; +} + + /** * Insert a key into an ibf. * @@ -455,13 +484,15 @@ prepare_ibf_iterator (void *cls, { struct Operation *op = cls; struct KeyEntry *ke = value; + struct IBF_Key salted_key; LOG (GNUNET_ERROR_TYPE_DEBUG, "[OP %x] inserting %lx (hash %s) into ibf\n", (void *) op, (unsigned long) ke->ibf_key.key_val, GNUNET_h2s (&ke->element->element_hash)); - ibf_insert (op->state->local_ibf, ke->ibf_key); + salt_key (&ke->ibf_key, op->state->salt_send, &salted_key); + ibf_insert (op->state->local_ibf, salted_key); return GNUNET_YES; } @@ -585,6 +616,7 @@ send_ibf (struct Operation *op, msg->reserved = 0; msg->order = ibf_order; msg->offset = htons (buckets_sent); + msg->salt = htonl (op->state->salt_send); ibf_write_slice (ibf, buckets_sent, buckets_in_message, &msg[1]); buckets_sent += buckets_in_message; @@ -879,6 +911,7 @@ decode_and_send (struct Operation *op) "# of IBF retries", 1, GNUNET_NO); + op->state->salt_send++; if (GNUNET_OK != send_ibf (op, next_order)) { @@ -920,19 +953,21 @@ decode_and_send (struct Operation *op) } if (1 == side) { - send_offers_for_key (op, key); + struct IBF_Key unsalted_key; + unsalt_key (&key, op->state->salt_receive, &unsalted_key); + send_offers_for_key (op, unsalted_key); } else if (-1 == side) { struct GNUNET_MQ_Envelope *ev; - struct GNUNET_MessageHeader *msg; + struct InquiryMessage *msg; /* It may be nice to merge multiple requests, but with CADET's corking it is not worth * the effort additional complexity. */ - ev = GNUNET_MQ_msg_header_extra (msg, - sizeof (struct IBF_Key), - GNUNET_MESSAGE_TYPE_SET_UNION_P2P_INQUIRY); - + ev = GNUNET_MQ_msg_extra (msg, + sizeof (struct IBF_Key), + GNUNET_MESSAGE_TYPE_SET_UNION_P2P_INQUIRY); + msg->salt = htonl (op->state->salt_receive); memcpy (&msg[1], &key, sizeof (struct IBF_Key)); @@ -986,6 +1021,7 @@ handle_p2p_ibf (void *cls, "Creating new ibf of size %u\n", 1 << msg->order); op->state->remote_ibf = ibf_create (1<order, SE_IBF_HASH_NUM); + op->state->salt_receive = ntohl (msg->salt); if (NULL == op->state->remote_ibf) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, @@ -1004,7 +1040,8 @@ handle_p2p_ibf (void *cls, else if (op->state->phase == PHASE_EXPECT_IBF_CONT) { if ( (ntohs (msg->offset) != op->state->ibf_buckets_received) || - (1<order != op->state->remote_ibf->size) ) + (1<order != op->state->remote_ibf->size) || + (ntohl (msg->salt) != op->state->salt_receive)) { GNUNET_break_op (0); fail_union_operation (op); @@ -1268,6 +1305,7 @@ handle_p2p_inquiry (void *cls, struct Operation *op = cls; const struct IBF_Key *ibf_key; unsigned int num_keys; + struct InquiryMessage *msg; /* look up elements and send them */ if (op->state->phase != PHASE_INVENTORY_PASSIVE) @@ -1276,9 +1314,9 @@ handle_p2p_inquiry (void *cls, fail_union_operation (op); return; } - num_keys = (ntohs (mh->size) - sizeof (struct GNUNET_MessageHeader)) + num_keys = (ntohs (mh->size) - sizeof (struct InquiryMessage)) / sizeof (struct IBF_Key); - if ((ntohs (mh->size) - sizeof (struct GNUNET_MessageHeader)) + if ((ntohs (mh->size) - sizeof (struct InquiryMessage)) != num_keys * sizeof (struct IBF_Key)) { GNUNET_break_op (0); @@ -1286,10 +1324,14 @@ handle_p2p_inquiry (void *cls, return; } - ibf_key = (const struct IBF_Key *) &mh[1]; + msg = (struct InquiryMessage *) mh; + + ibf_key = (const struct IBF_Key *) &msg[1]; while (0 != num_keys--) { - send_offers_for_key (op, *ibf_key); + struct IBF_Key unsalted_key; + unsalt_key (ibf_key, ntohl (msg->salt), &unsalted_key); + send_offers_for_key (op, unsalted_key); ibf_key++; } } @@ -1517,6 +1559,7 @@ union_evaluate (struct Operation *op, op->state->se = strata_estimator_dup (op->spec->set->state->se); /* we started the operation, thus we have to send the operation request */ op->state->phase = PHASE_EXPECT_SE; + op->state->salt_receive = op->state->salt_send = 42; LOG (GNUNET_ERROR_TYPE_DEBUG, "Initiating union operation evaluation\n"); GNUNET_STATISTICS_update (_GSS_statistics, @@ -1576,6 +1619,7 @@ union_accept (struct Operation *op) op->state = GNUNET_new (struct OperationState); op->state->se = strata_estimator_dup (op->spec->set->state->se); op->state->demanded_hashes = GNUNET_CONTAINER_multihashmap_create (32, GNUNET_NO); + op->state->salt_receive = op->state->salt_send = 42; /* kick off the operation */ send_strata_estimator (op); } @@ -1620,7 +1664,7 @@ static void union_add (struct SetState *set_state, struct ElementEntry *ee) { strata_estimator_insert (set_state->se, - get_ibf_key (&ee->element_hash, 0)); + get_ibf_key (&ee->element_hash)); } @@ -1635,7 +1679,7 @@ static void union_remove (struct SetState *set_state, struct ElementEntry *ee) { strata_estimator_remove (set_state->se, - get_ibf_key (&ee->element_hash, 0)); + get_ibf_key (&ee->element_hash)); } -- cgit v1.2.3