commit 8a33abcd65ebebf268750612d52684659f8df71d Author: David Goulet dgoulet@torproject.org Date: Mon Jan 9 11:33:05 2017 -0500

control: Add GETINFO command for the shared random values

Add the "sr/current" and "sr/previous" keys for the GETINFO command in order to get through the control port the shared random values from the consensus.

Closes #19925

Signed-off-by: David Goulet dgoulet@torproject.org --- src/or/control.c | 23 +++++++++++++++++++++++ src/or/shared_random.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ src/or/shared_random.h | 4 ++++ 3 files changed, 73 insertions(+)

diff --git a/src/or/control.c b/src/or/control.c index 248c780..9f342f1 100644 --- a/src/or/control.c +++ b/src/or/control.c @@ -71,6 +71,7 @@ #include "router.h" #include "routerlist.h" #include "routerparse.h" +#include "shared_random.h"

#ifndef _WIN32 #include <pwd.h> @@ -2870,6 +2871,26 @@ getinfo_helper_liveness(control_connection_t *control_conn, return 0; }

+/** Implementation helper for GETINFO: answers queries about shared random + * value. */ +static int +getinfo_helper_sr(control_connection_t *control_conn, + const char *question, char **answer, + const char **errmsg) +{ + (void) control_conn; + (void) errmsg; + + if (!strcmp(question, "sr/current")) { + *answer = sr_get_current_for_control(); + } else if(!strcmp(question, "sr/previous")) { + *answer = sr_get_previous_for_control(); + } + /* Else statement here is unrecognized key so do nothing. */ + + return 0; +} + /** Callback function for GETINFO: on a given control connection, try to * answer the question <b>q</b> and store the newly-allocated answer in * *<b>a</b>. If an internal error occurs, return -1 and optionally set @@ -3062,6 +3083,8 @@ static const getinfo_item_t getinfo_items[] = { "Onion services owned by the current control connection."), ITEM("onions/detached", onions, "Onion services detached from the control connection."), + ITEM("sr/current", sr, "Get current shared random value."), + ITEM("sr/previous", sr, "Get previous shared random value."), { NULL, NULL, NULL, 0 } };

diff --git a/src/or/shared_random.c b/src/or/shared_random.c index 0eb9338..f798a51 100644 --- a/src/or/shared_random.c +++ b/src/or/shared_random.c @@ -502,6 +502,20 @@ get_vote_line_from_commit(const sr_commit_t *commit, sr_phase_t phase) return vote_line; }

+/* Convert a given srv object to a string for the control port. This doesn't + * fail and the srv object MUST be valid. */ +static char * +srv_to_control_string(const sr_srv_t *srv) +{ + char *srv_str; + char srv_hash_encoded[SR_SRV_VALUE_BASE64_LEN + 1]; + tor_assert(srv); + + sr_srv_encode(srv_hash_encoded, sizeof(srv_hash_encoded), srv); + tor_asprintf(&srv_str, "%s", srv_hash_encoded); + return srv_str; +} + /* Return a heap allocated string that contains the given <b>srv</b> string * representation formatted for a networkstatus document using the * <b>key</b> as the start of the line. This doesn't return NULL. */ @@ -1348,6 +1362,38 @@ sr_save_and_cleanup(void) sr_cleanup(); }

+/* Return the current SRV string representation for the control port. Return a + * newly allocated string on success containing the value else "" if not found + * or if we don't have a valid consensus yet. */ +char * +sr_get_current_for_control(void) +{ + char *srv_str; + const networkstatus_t *c = networkstatus_get_latest_consensus(); + if (c && c->sr_info.current_srv) { + srv_str = srv_to_control_string(c->sr_info.current_srv); + } else { + srv_str = tor_strdup(""); + } + return srv_str; +} + +/* Return the previous SRV string representation for the control port. Return + * a newly allocated string on success containing the value else "" if not + * found or if we don't have a valid consensus yet. */ +char * +sr_get_previous_for_control(void) +{ + char *srv_str; + const networkstatus_t *c = networkstatus_get_latest_consensus(); + if (c && c->sr_info.previous_srv) { + srv_str = srv_to_control_string(c->sr_info.previous_srv); + } else { + srv_str = tor_strdup(""); + } + return srv_str; +} + #ifdef TOR_UNIT_TESTS

/* Set the global value of number of SRV agreements so the test can play diff --git a/src/or/shared_random.h b/src/or/shared_random.h index 9885934..dbb8eff 100644 --- a/src/or/shared_random.h +++ b/src/or/shared_random.h @@ -129,6 +129,10 @@ const char *sr_commit_get_rsa_fpr(const sr_commit_t *commit) void sr_compute_srv(void); sr_commit_t *sr_generate_our_commit(time_t timestamp, const authority_cert_t *my_rsa_cert); + +char *sr_get_current_for_control(void); +char *sr_get_previous_for_control(void); + #ifdef SHARED_RANDOM_PRIVATE

/* Encode */