nihilist/tor
1
0
Fork 0
mirror of https://gitlab.torproject.org/tpo/core/tor.git synced 2024-11-10 21:23:58 +01:00
Code Issues Packages Projects Releases Wiki Activity

Implement consensus method 12 (proposal 178)

Browse Source
This commit is contained in:
Sebastian Hahn 2011-02-20 21:05:17 -05:00 committed by Nick Mathewson
parent 40a87c4c08
commit e5e4bfd167
4 changed files with 104 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
changes/proposal178 Normal file
View File

@ -0,0 +1,6 @@
o Major features:
- Implement a more secure consensus parameter voting algorithm that
ensures that at least three directory authorities or a majority of
them voted on a given parameter before including it in the
consensus. Implements proposal 178.

32
src/or/dirvote.c
View File

@ -50,7 +50,7 @@ static int dirvote_publish_consensus(void);
static char *make_consensus_method_list(int low, int high, const char *sep);
/** The highest consensus method that we currently support. */
#define MAX_SUPPORTED_CONSENSUS_METHOD 11
#define MAX_SUPPORTED_CONSENSUS_METHOD 12
/** Lowest consensus method that contains a 'directory-footer' marker */
#define MIN_METHOD_FOR_FOOTER 9
@ -64,6 +64,10 @@ static char *make_consensus_method_list(int low, int high, const char *sep);
/** Lowest consensus method that generates microdescriptors */
#define MIN_METHOD_FOR_MICRODESC 8
/** Lowest consensus method that ensures a majority of authorities voted
* for a param. */
#define MIN_METHOD_FOR_MAJORITY_PARAMS 12
/* =====
* Voting
* =====*/
@ -608,11 +612,16 @@ compute_consensus_versions_list(smartlist_t *lst, int n_versioning)
return result;
}
/** Minimum number of directory authorities voting for a parameter to
* include it in the consensus, if consensus method 12 or later is to be
* used. See proposal 178 for details. */
#define MIN_VOTES_FOR_PARAM 3
/** Helper: given a list of valid networkstatus_t, return a new string
* containing the contents of the consensus network parameter set.
*/
/* private */ char *
dirvote_compute_params(smartlist_t *votes)
dirvote_compute_params(smartlist_t *votes, int method, int total_authorities)
{
int i;
int32_t *vals;
@ -669,11 +678,17 @@ dirvote_compute_params(smartlist_t *votes)
next_param = smartlist_get(param_list, param_sl_idx+1);
if (!next_param || strncmp(next_param, param, cur_param_len)) {
/* We've reached the end of a series. */
int32_t median = median_int32(vals, i);
char *out_string = tor_malloc(64+cur_param_len);
memcpy(out_string, param, cur_param_len);
tor_snprintf(out_string+cur_param_len,64, "%ld", (long)median);
smartlist_add(output, out_string);
/* Make sure enough authorities voted on this param, unless the
* the consensus method we use is too old for that. */
if (method < MIN_METHOD_FOR_MAJORITY_PARAMS ||
i > total_authorities/2 ||
i >= MIN_VOTES_FOR_PARAM) {
int32_t median = median_int32(vals, i);
char *out_string = tor_malloc(64+cur_param_len);
memcpy(out_string, param, cur_param_len);
tor_snprintf(out_string+cur_param_len,64, "%ld", (long)median);
smartlist_add(output, out_string);
}
i = 0;
if (next_param) {
@ -1496,7 +1511,8 @@ networkstatus_compute_consensus(smartlist_t *votes,
}
if (consensus_method >= MIN_METHOD_FOR_PARAMS) {
params = dirvote_compute_params(votes);
params = dirvote_compute_params(votes, consensus_method,
total_authorities);
if (params) {
smartlist_add(chunks, tor_strdup("params "));
smartlist_add(chunks, params);

3
src/or/dirvote.h
View File

@ -84,7 +84,8 @@ document_signature_t *voter_get_sig_by_algorithm(
#ifdef DIRVOTE_PRIVATE
char *format_networkstatus_vote(crypto_pk_env_t *private_key,
networkstatus_t *v3_ns);
char *dirvote_compute_params(smartlist_t *votes);
char *dirvote_compute_params(smartlist_t *votes, int method,
int total_authorities);
#endif
#endif

76
src/test/test_dir.c
View File

@ -620,13 +620,81 @@ test_dir_param_voting(void)
test_eq(0, networkstatus_get_param(&vote4, "foobar", 0, -100, 8));
smartlist_add(votes, &vote1);
/* Do the first tests without adding all the other votes, for
* networks without many dirauths. */
res = dirvote_compute_params(votes, 11, 6);
test_streq(res, "ab=90 abcd=20 cw=50 x-yz=-99");
tor_free(res);
res = dirvote_compute_params(votes, 12, 2);
test_streq(res, "");
tor_free(res);
res = dirvote_compute_params(votes, 12, 1);
test_streq(res, "ab=90 abcd=20 cw=50 x-yz=-99");
tor_free(res);
smartlist_add(votes, &vote2);
res = dirvote_compute_params(votes, 11, 2);
test_streq(res, "ab=27 abcd=20 cw=5 x-yz=-99");
tor_free(res);
res = dirvote_compute_params(votes, 12, 2);
test_streq(res, "ab=27 cw=5 x-yz=-99");
tor_free(res);
res = dirvote_compute_params(votes, 12, 3);
test_streq(res, "ab=27 cw=5 x-yz=-99");
tor_free(res);
res = dirvote_compute_params(votes, 12, 6);
test_streq(res, "");
tor_free(res);
smartlist_add(votes, &vote3);
res = dirvote_compute_params(votes, 11, 3);
test_streq(res, "ab=27 abcd=20 c=60 cw=50 x-yz=-9 zzzzz=101");
tor_free(res);
res = dirvote_compute_params(votes, 12, 3);
test_streq(res, "ab=27 abcd=20 cw=50 x-yz=-9");
tor_free(res);
res = dirvote_compute_params(votes, 12, 5);
test_streq(res, "cw=50 x-yz=-9");
tor_free(res);
res = dirvote_compute_params(votes, 12, 9);
test_streq(res, "cw=50 x-yz=-9");
tor_free(res);
smartlist_add(votes, &vote4);
res = dirvote_compute_params(votes);
test_streq(res,
"ab=90 abcd=20 c=1 cw=50 x-yz=-9 zzzzz=101");
res = dirvote_compute_params(votes, 11, 4);
test_streq(res, "ab=90 abcd=20 c=1 cw=50 x-yz=-9 zzzzz=101");
tor_free(res);
res = dirvote_compute_params(votes, 12, 4);
test_streq(res, "ab=90 abcd=20 cw=50 x-yz=-9");
tor_free(res);
res = dirvote_compute_params(votes, 12, 5);
test_streq(res, "ab=90 abcd=20 cw=50 x-yz=-9");
tor_free(res);
/* Test that the special-cased "at least three dirauths voted for
* this param" logic works as expected. */
res = dirvote_compute_params(votes, 12, 6);
test_streq(res, "ab=90 abcd=20 cw=50 x-yz=-9");
tor_free(res);
res = dirvote_compute_params(votes, 12, 10);
test_streq(res, "ab=90 abcd=20 cw=50 x-yz=-9");
tor_free(res);
done:
tor_free(res);
@ -1049,7 +1117,7 @@ test_dir_v3_networkstatus(void)
"Running:Stable:V2Dir:Valid");
tor_free(cp);
cp = smartlist_join_strings(con->net_params, ":", 0, NULL);
test_streq(cp, "bar=2000000000:circuitwindow=80:foo=660");
test_streq(cp, "circuitwindow=80:foo=660");
tor_free(cp);
test_eq(4, smartlist_len(con->voters)); /*3 voters, 1 legacy key.*/