[tor-commits] [tor/maint-0.4.0] Merge branch 'maint-0.3.4' into maint-0.3.5
teor at torproject.org
teor at torproject.org
Tue Mar 19 23:48:41 UTC 2019
commit 41cd05562f68c23f8c3d95472e20a86165f6dc20
Merge: 6bf9078ce d7a5fdcb7
Author: teor <teor at torproject.org>
Date: Wed Mar 20 09:48:03 2019 +1000
Merge branch 'maint-0.3.4' into maint-0.3.5
changes/bug29706_minimal | 4 ++++
src/feature/dirauth/shared_random_state.c | 4 ++--
src/feature/dirauth/shared_random_state.h | 2 ++
src/test/test_shared_random.c | 17 ++++++++++++++---
4 files changed, 22 insertions(+), 5 deletions(-)
diff --cc src/feature/dirauth/shared_random_state.c
index 2bc030f4a,000000000..b3e4a4ef9
mode 100644,000000..100644
--- a/src/feature/dirauth/shared_random_state.c
+++ b/src/feature/dirauth/shared_random_state.c
@@@ -1,1340 -1,0 +1,1340 @@@
+/* Copyright (c) 2016-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file shared_random_state.c
+ *
+ * \brief Functions and data structures for the state of the random protocol
+ * as defined in proposal #250.
+ **/
+
+#define SHARED_RANDOM_STATE_PRIVATE
+
+#include "core/or/or.h"
+#include "app/config/config.h"
+#include "app/config/confparse.h"
+#include "lib/crypt_ops/crypto_util.h"
+#include "feature/dirauth/dirvote.h"
+#include "feature/nodelist/networkstatus.h"
+#include "feature/relay/router.h"
+#include "feature/dirauth/shared_random.h"
+#include "feature/hs_common/shared_random_client.h"
+#include "feature/dirauth/shared_random_state.h"
+#include "feature/dircommon/voting_schedule.h"
+#include "lib/encoding/confline.h"
+
+#include "app/config/or_state_st.h"
+
+/* Default filename of the shared random state on disk. */
+static const char default_fname[] = "sr-state";
+
+/* String representation of a protocol phase. */
+static const char *phase_str[] = { "unknown", "commit", "reveal" };
+
+/* Our shared random protocol state. There is only one possible state per
+ * protocol run so this is the global state which is reset at every run once
+ * the shared random value has been computed. */
+static sr_state_t *sr_state = NULL;
+
+/* Representation of our persistent state on disk. The sr_state above
+ * contains the data parsed from this state. When we save to disk, we
+ * translate the sr_state to this sr_disk_state. */
+static sr_disk_state_t *sr_disk_state = NULL;
+
+/* Disk state file keys. */
+static const char dstate_commit_key[] = "Commit";
+static const char dstate_prev_srv_key[] = "SharedRandPreviousValue";
+static const char dstate_cur_srv_key[] = "SharedRandCurrentValue";
+
+/** dummy instance of sr_disk_state_t, used for type-checking its
+ * members with CONF_CHECK_VAR_TYPE. */
+DUMMY_TYPECHECK_INSTANCE(sr_disk_state_t);
+
+/* These next two are duplicates or near-duplicates from config.c */
+#define VAR(name, conftype, member, initvalue) \
+ { name, CONFIG_TYPE_ ## conftype, offsetof(sr_disk_state_t, member), \
+ initvalue CONF_TEST_MEMBERS(sr_disk_state_t, conftype, member) }
+/* As VAR, but the option name and member name are the same. */
+#define V(member, conftype, initvalue) \
+ VAR(#member, conftype, member, initvalue)
+/* Our persistent state magic number. */
+#define SR_DISK_STATE_MAGIC 0x98AB1254
+
+static int
+disk_state_validate_cb(void *old_state, void *state, void *default_state,
+ int from_setconf, char **msg);
+static void disk_state_free_cb(void *);
+
+/* Array of variables that are saved to disk as a persistent state. */
+static config_var_t state_vars[] = {
+ V(Version, UINT, "0"),
+ V(TorVersion, STRING, NULL),
+ V(ValidAfter, ISOTIME, NULL),
+ V(ValidUntil, ISOTIME, NULL),
+
+ V(Commit, LINELIST, NULL),
+
+ V(SharedRandValues, LINELIST_V, NULL),
+ VAR("SharedRandPreviousValue",LINELIST_S, SharedRandValues, NULL),
+ VAR("SharedRandCurrentValue", LINELIST_S, SharedRandValues, NULL),
+ END_OF_CONFIG_VARS
+};
+
+/* "Extra" variable in the state that receives lines we can't parse. This
+ * lets us preserve options from versions of Tor newer than us. */
+static config_var_t state_extra_var = {
+ "__extra", CONFIG_TYPE_LINELIST,
+ offsetof(sr_disk_state_t, ExtraLines), NULL
+ CONF_TEST_MEMBERS(sr_disk_state_t, LINELIST, ExtraLines)
+};
+
+/* Configuration format of sr_disk_state_t. */
+static const config_format_t state_format = {
+ sizeof(sr_disk_state_t),
+ SR_DISK_STATE_MAGIC,
+ offsetof(sr_disk_state_t, magic_),
+ NULL,
+ NULL,
+ state_vars,
+ disk_state_validate_cb,
+ disk_state_free_cb,
+ &state_extra_var,
+};
+
+/* Return a string representation of a protocol phase. */
+STATIC const char *
+get_phase_str(sr_phase_t phase)
+{
+ const char *the_string = NULL;
+
+ switch (phase) {
+ case SR_PHASE_COMMIT:
+ case SR_PHASE_REVEAL:
+ the_string = phase_str[phase];
+ break;
+ default:
+ /* Unknown phase shouldn't be possible. */
+ tor_assert(0);
+ }
+
+ return the_string;
+}
+/* Return the time we should expire the state file created at <b>now</b>.
+ * We expire the state file in the beginning of the next protocol run. */
+STATIC time_t
+get_state_valid_until_time(time_t now)
+{
+ int total_rounds = SHARED_RANDOM_N_ROUNDS * SHARED_RANDOM_N_PHASES;
+ int current_round, voting_interval, rounds_left;
+ time_t valid_until, beginning_of_current_round;
+
+ voting_interval = get_voting_interval();
+ /* Find the time the current round started. */
+ beginning_of_current_round = get_start_time_of_current_round();
+
+ /* Find how many rounds are left till the end of the protocol run */
+ current_round = (now / voting_interval) % total_rounds;
+ rounds_left = total_rounds - current_round;
+
+ /* To find the valid-until time now, take the start time of the current
+ * round and add to it the time it takes for the leftover rounds to
+ * complete. */
+ valid_until = beginning_of_current_round + (rounds_left * voting_interval);
+
+ { /* Logging */
+ char tbuf[ISO_TIME_LEN + 1];
+ format_iso_time(tbuf, valid_until);
+ log_debug(LD_DIR, "SR: Valid until time for state set to %s.", tbuf);
+ }
+
+ return valid_until;
+}
+
+/* Given the consensus 'valid-after' time, return the protocol phase we should
+ * be in. */
+STATIC sr_phase_t
+get_sr_protocol_phase(time_t valid_after)
+{
+ /* Shared random protocol has two phases, commit and reveal. */
+ int total_periods = SHARED_RANDOM_N_ROUNDS * SHARED_RANDOM_N_PHASES;
+ int current_slot;
+
+ /* Split time into slots of size 'voting_interval'. See which slot we are
+ * currently into, and find which phase it corresponds to. */
+ current_slot = (valid_after / get_voting_interval()) % total_periods;
+
+ if (current_slot < SHARED_RANDOM_N_ROUNDS) {
+ return SR_PHASE_COMMIT;
+ } else {
+ return SR_PHASE_REVEAL;
+ }
+}
+
+/* Add the given <b>commit</b> to <b>state</b>. It MUST be a valid commit
+ * and there shouldn't be a commit from the same authority in the state
+ * already else verification hasn't been done prior. This takes ownership of
+ * the commit once in our state. */
+static void
+commit_add_to_state(sr_commit_t *commit, sr_state_t *state)
+{
+ sr_commit_t *saved_commit;
+
+ tor_assert(commit);
+ tor_assert(state);
+
+ saved_commit = digestmap_set(state->commits, commit->rsa_identity,
+ commit);
+ if (saved_commit != NULL) {
+ /* This means we already have that commit in our state so adding twice
+ * the same commit is either a code flow error, a corrupted disk state
+ * or some new unknown issue. */
+ log_warn(LD_DIR, "SR: Commit from %s exists in our state while "
+ "adding it: '%s'", sr_commit_get_rsa_fpr(commit),
+ commit->encoded_commit);
+ sr_commit_free(saved_commit);
+ }
+}
+
+/* Helper: deallocate a commit object. (Used with digestmap_free(), which
+ * requires a function pointer whose argument is void *). */
+static void
+commit_free_(void *p)
+{
+ sr_commit_free_(p);
+}
+
+#define state_free(val) \
+ FREE_AND_NULL(sr_state_t, state_free_, (val))
+
+/* Free a state that was allocated with state_new(). */
+static void
+state_free_(sr_state_t *state)
+{
+ if (state == NULL) {
+ return;
+ }
+ tor_free(state->fname);
+ digestmap_free(state->commits, commit_free_);
+ tor_free(state->current_srv);
+ tor_free(state->previous_srv);
+ tor_free(state);
+}
+
+/* Allocate an sr_state_t object and returns it. If no <b>fname</b>, the
+ * default file name is used. This function does NOT initialize the state
+ * timestamp, phase or shared random value. NULL is never returned. */
+static sr_state_t *
+state_new(const char *fname, time_t now)
+{
+ sr_state_t *new_state = tor_malloc_zero(sizeof(*new_state));
+ /* If file name is not provided, use default. */
+ if (fname == NULL) {
+ fname = default_fname;
+ }
+ new_state->fname = tor_strdup(fname);
+ new_state->version = SR_PROTO_VERSION;
+ new_state->commits = digestmap_new();
+ new_state->phase = get_sr_protocol_phase(now);
+ new_state->valid_until = get_state_valid_until_time(now);
+ return new_state;
+}
+
+/* Set our global state pointer with the one given. */
+static void
+state_set(sr_state_t *state)
+{
+ tor_assert(state);
+ if (sr_state != NULL) {
+ state_free(sr_state);
+ }
+ sr_state = state;
+}
+
+#define disk_state_free(val) \
+ FREE_AND_NULL(sr_disk_state_t, disk_state_free_, (val))
+
+/* Free an allocated disk state. */
+static void
+disk_state_free_(sr_disk_state_t *state)
+{
+ if (state == NULL) {
+ return;
+ }
+ config_free(&state_format, state);
+}
+
+/* Allocate a new disk state, initialize it and return it. */
+static sr_disk_state_t *
+disk_state_new(time_t now)
+{
+ sr_disk_state_t *new_state = tor_malloc_zero(sizeof(*new_state));
+
+ new_state->magic_ = SR_DISK_STATE_MAGIC;
+ new_state->Version = SR_PROTO_VERSION;
+ new_state->TorVersion = tor_strdup(get_version());
+ new_state->ValidUntil = get_state_valid_until_time(now);
+ new_state->ValidAfter = now;
+
+ /* Init config format. */
+ config_init(&state_format, new_state);
+ return new_state;
+}
+
+/* Set our global disk state with the given state. */
+static void
+disk_state_set(sr_disk_state_t *state)
+{
+ tor_assert(state);
+ if (sr_disk_state != NULL) {
+ disk_state_free(sr_disk_state);
+ }
+ sr_disk_state = state;
+}
+
+/* Return -1 if the disk state is invalid (something in there that we can't or
+ * shouldn't use). Return 0 if everything checks out. */
+static int
+disk_state_validate(const sr_disk_state_t *state)
+{
+ time_t now;
+
+ tor_assert(state);
+
+ /* Do we support the protocol version in the state or is it 0 meaning
+ * Version wasn't found in the state file or bad anyway ? */
+ if (state->Version == 0 || state->Version > SR_PROTO_VERSION) {
+ goto invalid;
+ }
+
+ /* If the valid until time is before now, we shouldn't use that state. */
+ now = time(NULL);
+ if (state->ValidUntil < now) {
+ log_info(LD_DIR, "SR: Disk state has expired. Ignoring it.");
+ goto invalid;
+ }
+
+ /* Make sure we don't have a valid after time that is earlier than a valid
+ * until time which would make things not work well. */
+ if (state->ValidAfter >= state->ValidUntil) {
+ log_info(LD_DIR, "SR: Disk state valid after/until times are invalid.");
+ goto invalid;
+ }
+
+ return 0;
+
+ invalid:
+ return -1;
+}
+
+/* Validate the disk state (NOP for now). */
+static int
+disk_state_validate_cb(void *old_state, void *state, void *default_state,
+ int from_setconf, char **msg)
+{
+ /* We don't use these; only options do. */
+ (void) from_setconf;
+ (void) default_state;
+ (void) old_state;
+
+ /* This is called by config_dump which is just before we are about to
+ * write it to disk. At that point, our global memory state has been
+ * copied to the disk state so it's fair to assume it's trustable. */
+ (void) state;
+ (void) msg;
+ return 0;
+}
+
+static void
+disk_state_free_cb(void *state)
+{
+ disk_state_free_(state);
+}
+
+/* Parse the Commit line(s) in the disk state and translate them to the
+ * the memory state. Return 0 on success else -1 on error. */
+static int
+disk_state_parse_commits(sr_state_t *state,
+ const sr_disk_state_t *disk_state)
+{
+ config_line_t *line;
+ smartlist_t *args = NULL;
+
+ tor_assert(state);
+ tor_assert(disk_state);
+
+ for (line = disk_state->Commit; line; line = line->next) {
+ sr_commit_t *commit = NULL;
+
+ /* Extra safety. */
+ if (strcasecmp(line->key, dstate_commit_key) ||
+ line->value == NULL) {
+ /* Ignore any lines that are not commits. */
+ tor_fragile_assert();
+ continue;
+ }
+ args = smartlist_new();
+ smartlist_split_string(args, line->value, " ",
+ SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
+ if (smartlist_len(args) < 3) {
+ log_warn(LD_BUG, "SR: Too few arguments in Commit Line: %s",
+ escaped(line->value));
+ goto error;
+ }
+ commit = sr_parse_commit(args);
+ if (commit == NULL) {
+ /* Ignore badly formed commit. It could also be a authority
+ * fingerprint that we don't know about so it shouldn't be used. */
+ smartlist_free(args);
+ continue;
+ }
+ /* We consider parseable commit from our disk state to be valid because
+ * they need to be in the first place to get in there. */
+ commit->valid = 1;
+ /* Add commit to our state pointer. */
+ commit_add_to_state(commit, state);
+
+ SMARTLIST_FOREACH(args, char *, cp, tor_free(cp));
+ smartlist_free(args);
+ }
+
+ return 0;
+
+ error:
+ SMARTLIST_FOREACH(args, char *, cp, tor_free(cp));
+ smartlist_free(args);
+ return -1;
+}
+
+/* Parse a share random value line from the disk state and save it to dst
+ * which is an allocated srv object. Return 0 on success else -1. */
+static int
+disk_state_parse_srv(const char *value, sr_srv_t *dst)
+{
+ int ret = -1;
+ smartlist_t *args;
+ sr_srv_t *srv;
+
+ tor_assert(value);
+ tor_assert(dst);
+
+ args = smartlist_new();
+ smartlist_split_string(args, value, " ",
+ SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
+ if (smartlist_len(args) < 2) {
+ log_warn(LD_BUG, "SR: Too few arguments in shared random value. "
+ "Line: %s", escaped(value));
+ goto error;
+ }
+ srv = sr_parse_srv(args);
+ if (srv == NULL) {
+ goto error;
+ }
+ dst->num_reveals = srv->num_reveals;
+ memcpy(dst->value, srv->value, sizeof(dst->value));
+ tor_free(srv);
+ ret = 0;
+
+ error:
+ SMARTLIST_FOREACH(args, char *, s, tor_free(s));
+ smartlist_free(args);
+ return ret;
+}
+
+/* Parse both SharedRandCurrentValue and SharedRandPreviousValue line from
+ * the state. Return 0 on success else -1. */
+static int
+disk_state_parse_sr_values(sr_state_t *state,
+ const sr_disk_state_t *disk_state)
+{
+ /* Only one value per type (current or previous) is allowed so we keep
+ * track of it with these flag. */
+ unsigned int seen_previous = 0, seen_current = 0;
+ config_line_t *line;
+ sr_srv_t *srv = NULL;
+
+ tor_assert(state);
+ tor_assert(disk_state);
+
+ for (line = disk_state->SharedRandValues; line; line = line->next) {
+ if (line->value == NULL) {
+ continue;
+ }
+ srv = tor_malloc_zero(sizeof(*srv));
+ if (disk_state_parse_srv(line->value, srv) < 0) {
+ log_warn(LD_BUG, "SR: Broken current SRV line in state %s",
+ escaped(line->value));
+ goto bad;
+ }
+ if (!strcasecmp(line->key, dstate_prev_srv_key)) {
+ if (seen_previous) {
+ log_warn(LD_DIR, "SR: Second previous SRV value seen. Bad state");
+ goto bad;
+ }
+ state->previous_srv = srv;
+ seen_previous = 1;
+ } else if (!strcasecmp(line->key, dstate_cur_srv_key)) {
+ if (seen_current) {
+ log_warn(LD_DIR, "SR: Second current SRV value seen. Bad state");
+ goto bad;
+ }
+ state->current_srv = srv;
+ seen_current = 1;
+ } else {
+ /* Unknown key. Ignoring. */
+ tor_free(srv);
+ }
+ }
+
+ return 0;
+ bad:
+ tor_free(srv);
+ return -1;
+}
+
+/* Parse the given disk state and set a newly allocated state. On success,
+ * return that state else NULL. */
+static sr_state_t *
+disk_state_parse(const sr_disk_state_t *new_disk_state)
+{
+ sr_state_t *new_state = state_new(default_fname, time(NULL));
+
+ tor_assert(new_disk_state);
+
+ new_state->version = new_disk_state->Version;
+ new_state->valid_until = new_disk_state->ValidUntil;
+ new_state->valid_after = new_disk_state->ValidAfter;
+
+ /* Set our current phase according to the valid-after time in our disk
+ * state. The disk state we are parsing contains everything for the phase
+ * starting at valid_after so make sure our phase reflects that. */
+ new_state->phase = get_sr_protocol_phase(new_state->valid_after);
+
+ /* Parse the shared random values. */
+ if (disk_state_parse_sr_values(new_state, new_disk_state) < 0) {
+ goto error;
+ }
+ /* Parse the commits. */
+ if (disk_state_parse_commits(new_state, new_disk_state) < 0) {
+ goto error;
+ }
+ /* Great! This new state contains everything we had on disk. */
+ return new_state;
+
+ error:
+ state_free(new_state);
+ return NULL;
+}
+
+/* From a valid commit object and an allocated config line, set the line's
+ * value to the state string representation of a commit. */
+static void
+disk_state_put_commit_line(const sr_commit_t *commit, config_line_t *line)
+{
+ char *reveal_str = NULL;
+
+ tor_assert(commit);
+ tor_assert(line);
+
+ if (!tor_mem_is_zero(commit->encoded_reveal,
+ sizeof(commit->encoded_reveal))) {
+ /* Add extra whitespace so we can format the line correctly. */
+ tor_asprintf(&reveal_str, " %s", commit->encoded_reveal);
+ }
+ tor_asprintf(&line->value, "%u %s %s %s%s",
+ SR_PROTO_VERSION,
+ crypto_digest_algorithm_get_name(commit->alg),
+ sr_commit_get_rsa_fpr(commit),
+ commit->encoded_commit,
+ reveal_str != NULL ? reveal_str : "");
+ if (reveal_str != NULL) {
+ memwipe(reveal_str, 0, strlen(reveal_str));
+ tor_free(reveal_str);
+ }
+}
+
+/* From a valid srv object and an allocated config line, set the line's
+ * value to the state string representation of a shared random value. */
+static void
+disk_state_put_srv_line(const sr_srv_t *srv, config_line_t *line)
+{
+ char encoded[SR_SRV_VALUE_BASE64_LEN + 1];
+
+ tor_assert(line);
+
+ /* No SRV value thus don't add the line. This is possible since we might
+ * not have a current or previous SRV value in our state. */
+ if (srv == NULL) {
+ return;
+ }
+ sr_srv_encode(encoded, sizeof(encoded), srv);
+ tor_asprintf(&line->value, "%" PRIu64 " %s", srv->num_reveals, encoded);
+}
+
+/* Reset disk state that is free allocated memory and zeroed the object. */
+static void
+disk_state_reset(void)
+{
+ /* Free allocated memory */
+ config_free_lines(sr_disk_state->Commit);
+ config_free_lines(sr_disk_state->SharedRandValues);
+ config_free_lines(sr_disk_state->ExtraLines);
+ tor_free(sr_disk_state->TorVersion);
+
+ /* Clean up the struct */
+ memset(sr_disk_state, 0, sizeof(*sr_disk_state));
+
+ /* Reset it with useful data */
+ sr_disk_state->magic_ = SR_DISK_STATE_MAGIC;
+ sr_disk_state->TorVersion = tor_strdup(get_version());
+}
+
+/* Update our disk state based on our global SR state. */
+static void
+disk_state_update(void)
+{
+ config_line_t **next, *line;
+
+ if (BUG(!sr_disk_state))
+ return;
+ if (BUG(!sr_state))
+ return;
+
+ /* Reset current disk state. */
+ disk_state_reset();
+
+ /* First, update elements that we don't need to do a construction. */
+ sr_disk_state->Version = sr_state->version;
+ sr_disk_state->ValidUntil = sr_state->valid_until;
+ sr_disk_state->ValidAfter = sr_state->valid_after;
+
+ /* Shared random values. */
+ next = &sr_disk_state->SharedRandValues;
+ if (sr_state->previous_srv != NULL) {
+ *next = line = tor_malloc_zero(sizeof(config_line_t));
+ line->key = tor_strdup(dstate_prev_srv_key);
+ disk_state_put_srv_line(sr_state->previous_srv, line);
+ /* Go to the next shared random value. */
+ next = &(line->next);
+ }
+ if (sr_state->current_srv != NULL) {
+ *next = line = tor_malloc_zero(sizeof(*line));
+ line->key = tor_strdup(dstate_cur_srv_key);
+ disk_state_put_srv_line(sr_state->current_srv, line);
+ }
+
+ /* Parse the commits and construct config line(s). */
+ next = &sr_disk_state->Commit;
+ DIGESTMAP_FOREACH(sr_state->commits, key, sr_commit_t *, commit) {
+ *next = line = tor_malloc_zero(sizeof(*line));
+ line->key = tor_strdup(dstate_commit_key);
+ disk_state_put_commit_line(commit, line);
+ next = &(line->next);
+ } DIGESTMAP_FOREACH_END;
+}
+
+/* Load state from disk and put it into our disk state. If the state passes
+ * validation, our global state will be updated with it. Return 0 on
+ * success. On error, -EINVAL is returned if the state on disk did contained
+ * something malformed or is unreadable. -ENOENT is returned indicating that
+ * the state file is either empty of non existing. */
+static int
+disk_state_load_from_disk(void)
+{
+ int ret;
+ char *fname;
+
+ fname = get_datadir_fname(default_fname);
+ ret = disk_state_load_from_disk_impl(fname);
+ tor_free(fname);
+
+ return ret;
+}
+
+/* Helper for disk_state_load_from_disk(). */
+STATIC int
+disk_state_load_from_disk_impl(const char *fname)
+{
+ int ret;
+ char *content = NULL;
+ sr_state_t *parsed_state = NULL;
+ sr_disk_state_t *disk_state = NULL;
+
+ /* Read content of file so we can parse it. */
+ if ((content = read_file_to_str(fname, 0, NULL)) == NULL) {
+ log_warn(LD_FS, "SR: Unable to read SR state file %s",
+ escaped(fname));
+ ret = -errno;
+ goto error;
+ }
+
+ {
+ config_line_t *lines = NULL;
+ char *errmsg = NULL;
+
+ /* Every error in this code path will return EINVAL. */
+ ret = -EINVAL;
+ if (config_get_lines(content, &lines, 0) < 0) {
+ config_free_lines(lines);
+ goto error;
+ }
+
+ disk_state = disk_state_new(time(NULL));
+ config_assign(&state_format, disk_state, lines, 0, &errmsg);
+ config_free_lines(lines);
+ if (errmsg) {
+ log_warn(LD_DIR, "SR: Reading state error: %s", errmsg);
+ tor_free(errmsg);
+ goto error;
+ }
+ }
+
+ /* So far so good, we've loaded our state file into our disk state. Let's
+ * validate it and then parse it. */
+ if (disk_state_validate(disk_state) < 0) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ parsed_state = disk_state_parse(disk_state);
+ if (parsed_state == NULL) {
+ ret = -EINVAL;
+ goto error;
+ }
+ state_set(parsed_state);
+ disk_state_set(disk_state);
+ tor_free(content);
+ log_info(LD_DIR, "SR: State loaded successfully from file %s", fname);
+ return 0;
+
+ error:
+ disk_state_free(disk_state);
+ tor_free(content);
+ return ret;
+}
+
+/* Save the disk state to disk but before that update it from the current
+ * state so we always have the latest. Return 0 on success else -1. */
+static int
+disk_state_save_to_disk(void)
+{
+ int ret;
+ char *state, *content = NULL, *fname = NULL;
+ char tbuf[ISO_TIME_LEN + 1];
+ time_t now = time(NULL);
+
+ /* If we didn't have the opportunity to setup an internal disk state,
+ * don't bother saving something to disk. */
+ if (sr_disk_state == NULL) {
+ ret = 0;
+ goto done;
+ }
+
+ /* Make sure that our disk state is up to date with our memory state
+ * before saving it to disk. */
+ disk_state_update();
+ state = config_dump(&state_format, NULL, sr_disk_state, 0, 0);
+ format_local_iso_time(tbuf, now);
+ tor_asprintf(&content,
+ "# Tor shared random state file last generated on %s "
+ "local time\n"
+ "# Other times below are in UTC\n"
+ "# Please *do not* edit this file.\n\n%s",
+ tbuf, state);
+ tor_free(state);
+ fname = get_datadir_fname(default_fname);
+ if (write_str_to_file(fname, content, 0) < 0) {
+ log_warn(LD_FS, "SR: Unable to write SR state to file %s", fname);
+ ret = -1;
+ goto done;
+ }
+ ret = 0;
+ log_debug(LD_DIR, "SR: Saved state to file %s", fname);
+
+ done:
+ tor_free(fname);
+ tor_free(content);
+ return ret;
+}
+
+/* Reset our state to prepare for a new protocol run. Once this returns, all
+ * commits in the state will be removed and freed. */
+STATIC void
+reset_state_for_new_protocol_run(time_t valid_after)
+{
+ if (BUG(!sr_state))
+ return;
+
+ /* Keep counters in track */
+ sr_state->n_reveal_rounds = 0;
+ sr_state->n_commit_rounds = 0;
+ sr_state->n_protocol_runs++;
+
+ /* Reset valid-until */
+ sr_state->valid_until = get_state_valid_until_time(valid_after);
+ sr_state->valid_after = valid_after;
+
+ /* We are in a new protocol run so cleanup commits. */
+ sr_state_delete_commits();
+}
+
+/* This is the first round of the new protocol run starting at
+ * <b>valid_after</b>. Do the necessary housekeeping. */
+STATIC void
+new_protocol_run(time_t valid_after)
+{
+ sr_commit_t *our_commitment = NULL;
+
+ /* Only compute the srv at the end of the reveal phase. */
+ if (sr_state->phase == SR_PHASE_REVEAL) {
+ /* We are about to compute a new shared random value that will be set in
+ * our state as the current value so rotate values. */
+ state_rotate_srv();
+ /* Compute the shared randomness value of the day. */
+ sr_compute_srv();
+ }
+
+ /* Prepare for the new protocol run by reseting the state */
+ reset_state_for_new_protocol_run(valid_after);
+
+ /* Do some logging */
+ log_info(LD_DIR, "SR: Protocol run #%" PRIu64 " starting!",
+ sr_state->n_protocol_runs);
+
+ /* Generate fresh commitments for this protocol run */
+ our_commitment = sr_generate_our_commit(valid_after,
+ get_my_v3_authority_cert());
+ if (our_commitment) {
+ /* Add our commitment to our state. In case we are unable to create one
+ * (highly unlikely), we won't vote for this protocol run since our
+ * commitment won't be in our state. */
+ sr_state_add_commit(our_commitment);
+ }
+}
+
+/* Return 1 iff the <b>next_phase</b> is a phase transition from the current
+ * phase that is it's different. */
+STATIC int
+is_phase_transition(sr_phase_t next_phase)
+{
+ return sr_state->phase != next_phase;
+}
+
+/* Helper function: return a commit using the RSA fingerprint of the
+ * authority or NULL if no such commit is known. */
+static sr_commit_t *
+state_query_get_commit(const char *rsa_fpr)
+{
+ tor_assert(rsa_fpr);
+ return digestmap_get(sr_state->commits, rsa_fpr);
+}
+
+/* Helper function: This handles the GET state action using an
+ * <b>obj_type</b> and <b>data</b> needed for the action. */
+static void *
+state_query_get_(sr_state_object_t obj_type, const void *data)
+{
+ void *obj = NULL;
+
+ switch (obj_type) {
+ case SR_STATE_OBJ_COMMIT:
+ {
+ obj = state_query_get_commit(data);
+ break;
+ }
+ case SR_STATE_OBJ_COMMITS:
+ obj = sr_state->commits;
+ break;
+ case SR_STATE_OBJ_CURSRV:
+ obj = sr_state->current_srv;
+ break;
+ case SR_STATE_OBJ_PREVSRV:
+ obj = sr_state->previous_srv;
+ break;
+ case SR_STATE_OBJ_PHASE:
+ obj = &sr_state->phase;
+ break;
+ case SR_STATE_OBJ_VALID_AFTER:
+ default:
+ tor_assert(0);
+ }
+ return obj;
+}
+
+/* Helper function: This handles the PUT state action using an
+ * <b>obj_type</b> and <b>data</b> needed for the action. */
+static void
+state_query_put_(sr_state_object_t obj_type, void *data)
+{
+ switch (obj_type) {
+ case SR_STATE_OBJ_COMMIT:
+ {
+ sr_commit_t *commit = data;
+ tor_assert(commit);
+ commit_add_to_state(commit, sr_state);
+ break;
+ }
+ case SR_STATE_OBJ_CURSRV:
+ sr_state->current_srv = (sr_srv_t *) data;
+ break;
+ case SR_STATE_OBJ_PREVSRV:
+ sr_state->previous_srv = (sr_srv_t *) data;
+ break;
+ case SR_STATE_OBJ_VALID_AFTER:
+ sr_state->valid_after = *((time_t *) data);
+ break;
+ /* It's not allowed to change the phase nor the full commitments map from
+ * the state. The phase is decided during a strict process post voting and
+ * the commits should be put individually. */
+ case SR_STATE_OBJ_PHASE:
+ case SR_STATE_OBJ_COMMITS:
+ default:
+ tor_assert(0);
+ }
+}
+
+/* Helper function: This handles the DEL_ALL state action using an
+ * <b>obj_type</b> and <b>data</b> needed for the action. */
+static void
+state_query_del_all_(sr_state_object_t obj_type)
+{
+ switch (obj_type) {
+ case SR_STATE_OBJ_COMMIT:
+ {
+ /* We are in a new protocol run so cleanup commitments. */
+ DIGESTMAP_FOREACH_MODIFY(sr_state->commits, key, sr_commit_t *, c) {
+ sr_commit_free(c);
+ MAP_DEL_CURRENT(key);
+ } DIGESTMAP_FOREACH_END;
+ break;
+ }
+ /* The following object are _NOT_ suppose to be removed. */
+ case SR_STATE_OBJ_CURSRV:
+ case SR_STATE_OBJ_PREVSRV:
+ case SR_STATE_OBJ_PHASE:
+ case SR_STATE_OBJ_COMMITS:
+ case SR_STATE_OBJ_VALID_AFTER:
+ default:
+ tor_assert(0);
+ }
+}
+
+/* Helper function: This handles the DEL state action using an
+ * <b>obj_type</b> and <b>data</b> needed for the action. */
+static void
+state_query_del_(sr_state_object_t obj_type, void *data)
+{
+ (void) data;
+
+ switch (obj_type) {
+ case SR_STATE_OBJ_PREVSRV:
+ tor_free(sr_state->previous_srv);
+ break;
+ case SR_STATE_OBJ_CURSRV:
+ tor_free(sr_state->current_srv);
+ break;
+ case SR_STATE_OBJ_COMMIT:
+ case SR_STATE_OBJ_COMMITS:
+ case SR_STATE_OBJ_PHASE:
+ case SR_STATE_OBJ_VALID_AFTER:
+ default:
+ tor_assert(0);
+ }
+}
+
+/* Query state using an <b>action</b> for an object type <b>obj_type</b>.
+ * The <b>data</b> pointer needs to point to an object that the action needs
+ * to use and if anything is required to be returned, it is stored in
+ * <b>out</b>.
+ *
+ * This mechanism exists so we have one single point where we synchronized
+ * our memory state with our disk state for every actions that changes it.
+ * We then trigger a write on disk immediately.
+ *
+ * This should be the only entry point to our memory state. It's used by all
+ * our state accessors and should be in the future. */
+static void
+state_query(sr_state_action_t action, sr_state_object_t obj_type,
+ void *data, void **out)
+{
+ switch (action) {
+ case SR_STATE_ACTION_GET:
+ *out = state_query_get_(obj_type, data);
+ break;
+ case SR_STATE_ACTION_PUT:
+ state_query_put_(obj_type, data);
+ break;
+ case SR_STATE_ACTION_DEL:
+ state_query_del_(obj_type, data);
+ break;
+ case SR_STATE_ACTION_DEL_ALL:
+ state_query_del_all_(obj_type);
+ break;
+ case SR_STATE_ACTION_SAVE:
+ /* Only trigger a disk state save. */
+ break;
+ default:
+ tor_assert(0);
+ }
+
+ /* If the action actually changes the state, immediately save it to disk.
+ * The following will sync the state -> disk state and then save it. */
+ if (action != SR_STATE_ACTION_GET) {
+ disk_state_save_to_disk();
+ }
+}
+
+/* Delete the current SRV value from the state freeing it and the value is set
+ * to NULL meaning empty. */
- static void
++STATIC void
+state_del_current_srv(void)
+{
+ state_query(SR_STATE_ACTION_DEL, SR_STATE_OBJ_CURSRV, NULL, NULL);
+}
+
+/* Delete the previous SRV value from the state freeing it and the value is
+ * set to NULL meaning empty. */
- static void
++STATIC void
+state_del_previous_srv(void)
+{
+ state_query(SR_STATE_ACTION_DEL, SR_STATE_OBJ_PREVSRV, NULL, NULL);
+}
+
+/* Rotate SRV value by freeing the previous value, assigning the current
+ * value to the previous one and nullifying the current one. */
+STATIC void
+state_rotate_srv(void)
+{
+ /* First delete previous SRV from the state. Object will be freed. */
+ state_del_previous_srv();
+ /* Set previous SRV with the current one. */
+ sr_state_set_previous_srv(sr_state_get_current_srv());
+ /* Nullify the current srv. */
+ sr_state_set_current_srv(NULL);
+}
+
+/* Set valid after time in the our state. */
+void
+sr_state_set_valid_after(time_t valid_after)
+{
+ state_query(SR_STATE_ACTION_PUT, SR_STATE_OBJ_VALID_AFTER,
+ (void *) &valid_after, NULL);
+}
+
+/* Return the phase we are currently in according to our state. */
+sr_phase_t
+sr_state_get_phase(void)
+{
+ void *ptr;
+ state_query(SR_STATE_ACTION_GET, SR_STATE_OBJ_PHASE, NULL, &ptr);
+ return *(sr_phase_t *) ptr;
+}
+
+/* Return the previous SRV value from our state. Value CAN be NULL. */
+const sr_srv_t *
+sr_state_get_previous_srv(void)
+{
+ const sr_srv_t *srv;
+ state_query(SR_STATE_ACTION_GET, SR_STATE_OBJ_PREVSRV, NULL,
+ (void *) &srv);
+ return srv;
+}
+
+/* Set the current SRV value from our state. Value CAN be NULL. The srv
+ * object ownership is transferred to the state object. */
+void
+sr_state_set_previous_srv(const sr_srv_t *srv)
+{
+ state_query(SR_STATE_ACTION_PUT, SR_STATE_OBJ_PREVSRV, (void *) srv,
+ NULL);
+}
+
+/* Return the current SRV value from our state. Value CAN be NULL. */
+const sr_srv_t *
+sr_state_get_current_srv(void)
+{
+ const sr_srv_t *srv;
+ state_query(SR_STATE_ACTION_GET, SR_STATE_OBJ_CURSRV, NULL,
+ (void *) &srv);
+ return srv;
+}
+
+/* Set the current SRV value from our state. Value CAN be NULL. The srv
+ * object ownership is transferred to the state object. */
+void
+sr_state_set_current_srv(const sr_srv_t *srv)
+{
+ state_query(SR_STATE_ACTION_PUT, SR_STATE_OBJ_CURSRV, (void *) srv,
+ NULL);
+}
+
+/* Clean all the SRVs in our state. */
+void
+sr_state_clean_srvs(void)
+{
+ /* Remove SRVs from state. They will be set to NULL as "empty". */
+ state_del_previous_srv();
+ state_del_current_srv();
+}
+
+/* Return a pointer to the commits map from our state. CANNOT be NULL. */
+digestmap_t *
+sr_state_get_commits(void)
+{
+ digestmap_t *commits;
+ state_query(SR_STATE_ACTION_GET, SR_STATE_OBJ_COMMITS,
+ NULL, (void *) &commits);
+ tor_assert(commits);
+ return commits;
+}
+
+/* Update the current SR state as needed for the upcoming voting round at
+ * <b>valid_after</b>. */
+void
+sr_state_update(time_t valid_after)
+{
+ sr_phase_t next_phase;
+
+ if (BUG(!sr_state))
+ return;
+
+ /* Don't call this function twice in the same voting period. */
+ if (valid_after <= sr_state->valid_after) {
+ log_info(LD_DIR, "SR: Asked to update state twice. Ignoring.");
+ return;
+ }
+
+ /* Get phase of upcoming round. */
+ next_phase = get_sr_protocol_phase(valid_after);
+
+ /* If we are transitioning to a new protocol phase, prepare the stage. */
+ if (is_phase_transition(next_phase)) {
+ if (next_phase == SR_PHASE_COMMIT) {
+ /* Going into commit phase means we are starting a new protocol run. */
+ new_protocol_run(valid_after);
+ }
+ /* Set the new phase for this round */
+ sr_state->phase = next_phase;
+ } else if (sr_state->phase == SR_PHASE_COMMIT &&
+ digestmap_size(sr_state->commits) == 0) {
+ /* We are _NOT_ in a transition phase so if we are in the commit phase
+ * and have no commit, generate one. Chances are that we are booting up
+ * so let's have a commit in our state for the next voting period. */
+ sr_commit_t *our_commit =
+ sr_generate_our_commit(valid_after, get_my_v3_authority_cert());
+ if (our_commit) {
+ /* Add our commitment to our state. In case we are unable to create one
+ * (highly unlikely), we won't vote for this protocol run since our
+ * commitment won't be in our state. */
+ sr_state_add_commit(our_commit);
+ }
+ }
+
+ sr_state_set_valid_after(valid_after);
+
+ /* Count the current round */
+ if (sr_state->phase == SR_PHASE_COMMIT) {
+ /* invariant check: we've not entered reveal phase yet */
+ if (BUG(sr_state->n_reveal_rounds != 0))
+ return;
+ sr_state->n_commit_rounds++;
+ } else {
+ sr_state->n_reveal_rounds++;
+ }
+
+ { /* Debugging. */
+ char tbuf[ISO_TIME_LEN + 1];
+ format_iso_time(tbuf, valid_after);
+ log_info(LD_DIR, "SR: State prepared for upcoming voting period (%s). "
+ "Upcoming phase is %s (counters: %d commit & %d reveal rounds).",
+ tbuf, get_phase_str(sr_state->phase),
+ sr_state->n_commit_rounds, sr_state->n_reveal_rounds);
+ }
+}
+
+/* Return commit object from the given authority digest <b>rsa_identity</b>.
+ * Return NULL if not found. */
+sr_commit_t *
+sr_state_get_commit(const char *rsa_identity)
+{
+ sr_commit_t *commit;
+
+ tor_assert(rsa_identity);
+
+ state_query(SR_STATE_ACTION_GET, SR_STATE_OBJ_COMMIT,
+ (void *) rsa_identity, (void *) &commit);
+ return commit;
+}
+
+/* Add <b>commit</b> to the permanent state. The commit object ownership is
+ * transferred to the state so the caller MUST not free it. */
+void
+sr_state_add_commit(sr_commit_t *commit)
+{
+ tor_assert(commit);
+
+ /* Put the commit to the global state. */
+ state_query(SR_STATE_ACTION_PUT, SR_STATE_OBJ_COMMIT,
+ (void *) commit, NULL);
+
+ log_debug(LD_DIR, "SR: Commit from %s has been added to our state.",
+ sr_commit_get_rsa_fpr(commit));
+}
+
+/* Remove all commits from our state. */
+void
+sr_state_delete_commits(void)
+{
+ state_query(SR_STATE_ACTION_DEL_ALL, SR_STATE_OBJ_COMMIT, NULL, NULL);
+}
+
+/* Copy the reveal information from <b>commit</b> into <b>saved_commit</b>.
+ * This <b>saved_commit</b> MUST come from our current SR state. Once modified,
+ * the disk state is updated. */
+void
+sr_state_copy_reveal_info(sr_commit_t *saved_commit, const sr_commit_t *commit)
+{
+ tor_assert(saved_commit);
+ tor_assert(commit);
+
+ saved_commit->reveal_ts = commit->reveal_ts;
+ memcpy(saved_commit->random_number, commit->random_number,
+ sizeof(saved_commit->random_number));
+
+ strlcpy(saved_commit->encoded_reveal, commit->encoded_reveal,
+ sizeof(saved_commit->encoded_reveal));
+ state_query(SR_STATE_ACTION_SAVE, 0, NULL, NULL);
+ log_debug(LD_DIR, "SR: Reveal value learned %s (for commit %s) from %s",
+ saved_commit->encoded_reveal, saved_commit->encoded_commit,
+ sr_commit_get_rsa_fpr(saved_commit));
+}
+
+/* Set the fresh SRV flag from our state. This doesn't need to trigger a
+ * disk state synchronization so we directly change the state. */
+void
+sr_state_set_fresh_srv(void)
+{
+ sr_state->is_srv_fresh = 1;
+}
+
+/* Unset the fresh SRV flag from our state. This doesn't need to trigger a
+ * disk state synchronization so we directly change the state. */
+void
+sr_state_unset_fresh_srv(void)
+{
+ sr_state->is_srv_fresh = 0;
+}
+
+/* Return the value of the fresh SRV flag. */
+unsigned int
+sr_state_srv_is_fresh(void)
+{
+ return sr_state->is_srv_fresh;
+}
+
+/* Cleanup and free our disk and memory state. */
+void
+sr_state_free_all(void)
+{
+ state_free(sr_state);
+ disk_state_free(sr_disk_state);
+ /* Nullify our global state. */
+ sr_state = NULL;
+ sr_disk_state = NULL;
+}
+
+/* Save our current state in memory to disk. */
+void
+sr_state_save(void)
+{
+ /* Query a SAVE action on our current state so it's synced and saved. */
+ state_query(SR_STATE_ACTION_SAVE, 0, NULL, NULL);
+}
+
+/* Return 1 iff the state has been initialized that is it exists in memory.
+ * Return 0 otherwise. */
+int
+sr_state_is_initialized(void)
+{
+ return sr_state == NULL ? 0 : 1;
+}
+
+/* Initialize the disk and memory state.
+ *
+ * If save_to_disk is set to 1, the state is immediately saved to disk after
+ * creation else it's not thus only kept in memory.
+ * If read_from_disk is set to 1, we try to load the state from the disk and
+ * if not found, a new state is created.
+ *
+ * Return 0 on success else a negative value on error. */
+int
+sr_state_init(int save_to_disk, int read_from_disk)
+{
+ int ret = -ENOENT;
+ time_t now = time(NULL);
+
+ /* We shouldn't have those assigned. */
+ tor_assert(sr_disk_state == NULL);
+ tor_assert(sr_state == NULL);
+
+ /* First, try to load the state from disk. */
+ if (read_from_disk) {
+ ret = disk_state_load_from_disk();
+ }
+
+ if (ret < 0) {
+ switch (-ret) {
+ case EINVAL:
+ /* We have a state on disk but it contains something we couldn't parse
+ * or an invalid entry in the state file. Let's remove it since it's
+ * obviously unusable and replace it by an new fresh state below. */
+ case ENOENT:
+ {
+ /* No state on disk so allocate our states for the first time. */
+ sr_state_t *new_state = state_new(default_fname, now);
+ sr_disk_state_t *new_disk_state = disk_state_new(now);
+ state_set(new_state);
+ /* It's important to set our disk state pointer since the save call
+ * below uses it to synchronized it with our memory state. */
+ disk_state_set(new_disk_state);
+ /* No entry, let's save our new state to disk. */
+ if (save_to_disk && disk_state_save_to_disk() < 0) {
+ goto error;
+ }
+ break;
+ }
+ default:
+ /* Big problem. Not possible. */
+ tor_assert(0);
+ }
+ }
+ /* We have a state in memory, let's make sure it's updated for the current
+ * and next voting round. */
+ {
+ time_t valid_after = voting_schedule_get_next_valid_after_time();
+ sr_state_update(valid_after);
+ }
+ return 0;
+
+ error:
+ return -1;
+}
+
+#ifdef TOR_UNIT_TESTS
+
+/* Set the current phase of the protocol. Used only by unit tests. */
+void
+set_sr_phase(sr_phase_t phase)
+{
+ if (BUG(!sr_state))
+ return;
+ sr_state->phase = phase;
+}
+
+/* Get the SR state. Used only by unit tests */
+sr_state_t *
+get_sr_state(void)
+{
+ return sr_state;
+}
+
+#endif /* defined(TOR_UNIT_TESTS) */
diff --cc src/feature/dirauth/shared_random_state.h
index 35626be3f,000000000..08f999f9d
mode 100644,000000..100644
--- a/src/feature/dirauth/shared_random_state.h
+++ b/src/feature/dirauth/shared_random_state.h
@@@ -1,146 -1,0 +1,148 @@@
+/* Copyright (c) 2016-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef TOR_SHARED_RANDOM_STATE_H
+#define TOR_SHARED_RANDOM_STATE_H
+
+#include "feature/dirauth/shared_random.h"
+
+/* Action that can be performed on the state for any objects. */
+typedef enum {
+ SR_STATE_ACTION_GET = 1,
+ SR_STATE_ACTION_PUT = 2,
+ SR_STATE_ACTION_DEL = 3,
+ SR_STATE_ACTION_DEL_ALL = 4,
+ SR_STATE_ACTION_SAVE = 5,
+} sr_state_action_t;
+
+/* Object in the state that can be queried through the state API. */
+typedef enum {
+ /* Will return a single commit using an authority identity key. */
+ SR_STATE_OBJ_COMMIT,
+ /* Returns the entire list of commits from the state. */
+ SR_STATE_OBJ_COMMITS,
+ /* Return the current SRV object pointer. */
+ SR_STATE_OBJ_CURSRV,
+ /* Return the previous SRV object pointer. */
+ SR_STATE_OBJ_PREVSRV,
+ /* Return the phase. */
+ SR_STATE_OBJ_PHASE,
+ /* Get or Put the valid after time. */
+ SR_STATE_OBJ_VALID_AFTER,
+} sr_state_object_t;
+
+/* State of the protocol. It's also saved on disk in fname. This data
+ * structure MUST be synchronized at all time with the one on disk. */
+typedef struct sr_state_t {
+ /* Filename of the state file on disk. */
+ char *fname;
+ /* Version of the protocol. */
+ uint32_t version;
+ /* The valid-after of the voting period we have prepared the state for. */
+ time_t valid_after;
+ /* Until when is this state valid? */
+ time_t valid_until;
+ /* Protocol phase. */
+ sr_phase_t phase;
+
+ /* Number of runs completed. */
+ uint64_t n_protocol_runs;
+ /* The number of commitment rounds we've performed in this protocol run. */
+ unsigned int n_commit_rounds;
+ /* The number of reveal rounds we've performed in this protocol run. */
+ unsigned int n_reveal_rounds;
+
+ /* A map of all the received commitments for this protocol run. This is
+ * indexed by authority RSA identity digest. */
+ digestmap_t *commits;
+
+ /* Current and previous shared random value. */
+ sr_srv_t *previous_srv;
+ sr_srv_t *current_srv;
+
+ /* Indicate if the state contains an SRV that was _just_ generated. This is
+ * used during voting so that we know whether to use the super majority rule
+ * or not when deciding on keeping it for the consensus. It is _always_ set
+ * to 0 post consensus.
+ *
+ * EDGE CASE: if an authority computes a new SRV then immediately reboots
+ * and, once back up, votes for the current round, it won't know if the
+ * SRV is fresh or not ultimately making it _NOT_ use the super majority
+ * when deciding to put or not the SRV in the consensus. This is for now
+ * an acceptable very rare edge case. */
+ unsigned int is_srv_fresh:1;
+} sr_state_t;
+
+/* Persistent state of the protocol, as saved to disk. */
+typedef struct sr_disk_state_t {
+ uint32_t magic_;
+ /* Version of the protocol. */
+ int Version;
+ /* Version of our running tor. */
+ char *TorVersion;
+ /* Creation time of this state */
+ time_t ValidAfter;
+ /* State valid until? */
+ time_t ValidUntil;
+ /* All commits seen that are valid. */
+ struct config_line_t *Commit;
+ /* Previous and current shared random value. */
+ struct config_line_t *SharedRandValues;
+ /* Extra Lines for configuration we might not know. */
+ struct config_line_t *ExtraLines;
+} sr_disk_state_t;
+
+/* API */
+
+/* Public methods: */
+
+void sr_state_update(time_t valid_after);
+
+/* Private methods (only used by shared-random.c): */
+
+void sr_state_set_valid_after(time_t valid_after);
+sr_phase_t sr_state_get_phase(void);
+const sr_srv_t *sr_state_get_previous_srv(void);
+const sr_srv_t *sr_state_get_current_srv(void);
+void sr_state_set_previous_srv(const sr_srv_t *srv);
+void sr_state_set_current_srv(const sr_srv_t *srv);
+void sr_state_clean_srvs(void);
+digestmap_t *sr_state_get_commits(void);
+sr_commit_t *sr_state_get_commit(const char *rsa_fpr);
+void sr_state_add_commit(sr_commit_t *commit);
+void sr_state_delete_commits(void);
+void sr_state_copy_reveal_info(sr_commit_t *saved_commit,
+ const sr_commit_t *commit);
+unsigned int sr_state_srv_is_fresh(void);
+void sr_state_set_fresh_srv(void);
+void sr_state_unset_fresh_srv(void);
+int sr_state_init(int save_to_disk, int read_from_disk);
+int sr_state_is_initialized(void);
+void sr_state_save(void);
+void sr_state_free_all(void);
+
+#ifdef SHARED_RANDOM_STATE_PRIVATE
+
+STATIC int disk_state_load_from_disk_impl(const char *fname);
+
+STATIC sr_phase_t get_sr_protocol_phase(time_t valid_after);
+
+STATIC time_t get_state_valid_until_time(time_t now);
+STATIC const char *get_phase_str(sr_phase_t phase);
+STATIC void reset_state_for_new_protocol_run(time_t valid_after);
+STATIC void new_protocol_run(time_t valid_after);
+STATIC void state_rotate_srv(void);
+STATIC int is_phase_transition(sr_phase_t next_phase);
+
+#endif /* defined(SHARED_RANDOM_STATE_PRIVATE) */
+
+#ifdef TOR_UNIT_TESTS
+
+STATIC void set_sr_phase(sr_phase_t phase);
+STATIC sr_state_t *get_sr_state(void);
++STATIC void state_del_previous_srv(void);
++STATIC void state_del_current_srv(void);
+
+#endif /* defined(TOR_UNIT_TESTS) */
+
+#endif /* !defined(TOR_SHARED_RANDOM_STATE_H) */
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