tor/src/feature/dirparse/routerparse.c

/* Copyright (c) 2001 Matej Pfajfar.
 * Copyright (c) 2001-2004, Roger Dingledine.
 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
 * Copyright (c) 2007-2018, The Tor Project, Inc. */
/* See LICENSE for licensing information */

/**
 * \file routerparse.c
 * \brief Code to parse and validate router descriptors, consenus directories,
 *   and similar objects.
 *
 * The objects parsed by this module use a common text-based metaformat,
 * documented in dir-spec.txt in torspec.git.  This module is itself divided
 * into two major kinds of function: code to handle the metaformat, and code
 * to convert from particular instances of the metaformat into the
 * objects that Tor uses.
 *
 * The generic parsing code works by calling a table-based tokenizer on the
 * input string.  Each token corresponds to a single line with a token, plus
 * optional arguments on that line, plus an optional base-64 encoded object
 * after that line.  Each token has a definition in a table of token_rule_t
 * entries that describes how many arguments it can take, whether it takes an
 * object, how many times it may appear, whether it must appear first, and so
 * on.
 *
 * The tokenizer function tokenize_string() converts its string input into a
 * smartlist full of instances of directory_token_t, according to a provided
 * table of token_rule_t.
 *
 * The generic parts of this module additionally include functions for
 * finding the start and end of signed information inside a signed object, and
 * computing the digest that will be signed.
 *
 * There are also functions for saving objects to disk that have caused
 * parsing to fail.
 *
 * The specific parts of this module describe conversions between
 * particular lists of directory_token_t and particular objects.  The
 * kinds of objects that can be parsed here are:
 *  <ul>
 *  <li>router descriptors (managed from routerlist.c)
 *  <li>extra-info documents (managed from routerlist.c)
 *  <li>microdescriptors (managed from microdesc.c)
 *  <li>vote and consensus networkstatus documents, and the routerstatus_t
 *    objects that they comprise (managed from networkstatus.c)
 *  <li>detached-signature objects used by authorities for gathering
 *    signatures on the networkstatus consensus (managed from dirvote.c)
 *  <li>authority key certificates (managed from routerlist.c)
 *  <li>hidden service descriptors (managed from rendcommon.c and rendcache.c)
 * </ul>
 **/

#define ROUTERPARSE_PRIVATE

#include "core/or/or.h"
#include "app/config/config.h"
#include "core/or/circuitstats.h"
#include "core/or/policies.h"
#include "core/or/protover.h"
#include "feature/client/entrynodes.h"
#include "feature/dirauth/shared_random.h"
#include "feature/dircommon/voting_schedule.h"
#include "feature/dirparse/parsecommon.h"
#include "feature/dirparse/routerparse.h"
#include "feature/hs_common/shared_random_client.h"
#include "feature/nodelist/authcert.h"
#include "feature/nodelist/describe.h"
#include "feature/nodelist/microdesc.h"
#include "feature/nodelist/networkstatus.h"
#include "feature/nodelist/nickname.h"
#include "feature/nodelist/routerinfo.h"
#include "feature/nodelist/routerlist.h"
#include "feature/nodelist/torcert.h"
#include "feature/relay/router.h"
#include "feature/relay/routerkeys.h"
#include "feature/rend/rendcommon.h"
#include "feature/stats/rephist.h"
#include "lib/crypt_ops/crypto_format.h"
#include "lib/crypt_ops/crypto_util.h"
#include "lib/memarea/memarea.h"
#include "lib/sandbox/sandbox.h"
#include "feature/dirparse/authcert_parse.h"
#include "feature/dirparse/sigcommon.h"
#include "feature/dirparse/unparseable.h"

#include "feature/dirauth/dirvote.h"

#include "core/or/addr_policy_st.h"
#include "feature/nodelist/authority_cert_st.h"
#include "feature/nodelist/document_signature_st.h"
#include "core/or/extend_info_st.h"
#include "feature/nodelist/extrainfo_st.h"
#include "feature/nodelist/microdesc_st.h"
#include "feature/nodelist/networkstatus_st.h"
#include "feature/nodelist/networkstatus_voter_info_st.h"
#include "feature/dirauth/ns_detached_signatures_st.h"
#include "feature/rend/rend_authorized_client_st.h"
#include "feature/rend/rend_intro_point_st.h"
#include "feature/rend/rend_service_descriptor_st.h"
#include "feature/nodelist/routerinfo_st.h"
#include "feature/nodelist/routerlist_st.h"
#include "core/or/tor_version_st.h"
#include "feature/dirauth/vote_microdesc_hash_st.h"
#include "feature/nodelist/vote_routerstatus_st.h"

#include "lib/container/bloomfilt.h"

#undef log
#include <math.h>

/****************************************************************************/

/** List of tokens recognized in router descriptors */
static token_rule_t routerdesc_token_table[] = {
  T0N("reject",              K_REJECT,              ARGS,    NO_OBJ ),
  T0N("accept",              K_ACCEPT,              ARGS,    NO_OBJ ),
  T0N("reject6",             K_REJECT6,             ARGS,    NO_OBJ ),
  T0N("accept6",             K_ACCEPT6,             ARGS,    NO_OBJ ),
  T1_START( "router",        K_ROUTER,              GE(5),   NO_OBJ ),
  T01("ipv6-policy",         K_IPV6_POLICY,         CONCAT_ARGS, NO_OBJ),
  T1( "signing-key",         K_SIGNING_KEY,         NO_ARGS, NEED_KEY_1024 ),
  T1( "onion-key",           K_ONION_KEY,           NO_ARGS, NEED_KEY_1024 ),
  T01("ntor-onion-key",      K_ONION_KEY_NTOR,      GE(1), NO_OBJ ),
  T1_END( "router-signature",    K_ROUTER_SIGNATURE,    NO_ARGS, NEED_OBJ ),
  T1( "published",           K_PUBLISHED,       CONCAT_ARGS, NO_OBJ ),
  T01("uptime",              K_UPTIME,              GE(1),   NO_OBJ ),
  T01("fingerprint",         K_FINGERPRINT,     CONCAT_ARGS, NO_OBJ ),
  T01("hibernating",         K_HIBERNATING,         GE(1),   NO_OBJ ),
  T01("platform",            K_PLATFORM,        CONCAT_ARGS, NO_OBJ ),
  T01("proto",               K_PROTO,           CONCAT_ARGS, NO_OBJ ),
  T01("contact",             K_CONTACT,         CONCAT_ARGS, NO_OBJ ),
  T01("read-history",        K_READ_HISTORY,        ARGS,    NO_OBJ ),
  T01("write-history",       K_WRITE_HISTORY,       ARGS,    NO_OBJ ),
  T01("extra-info-digest",   K_EXTRA_INFO_DIGEST,   GE(1),   NO_OBJ ),
  T01("hidden-service-dir",  K_HIDDEN_SERVICE_DIR,  NO_ARGS, NO_OBJ ),
  T01("identity-ed25519",    K_IDENTITY_ED25519,    NO_ARGS, NEED_OBJ ),
  T01("master-key-ed25519",  K_MASTER_KEY_ED25519,  GE(1),   NO_OBJ ),
  T01("router-sig-ed25519",  K_ROUTER_SIG_ED25519,  GE(1),   NO_OBJ ),
  T01("onion-key-crosscert", K_ONION_KEY_CROSSCERT, NO_ARGS, NEED_OBJ ),
  T01("ntor-onion-key-crosscert", K_NTOR_ONION_KEY_CROSSCERT,
                                                    EQ(1),   NEED_OBJ ),

  T01("allow-single-hop-exits",K_ALLOW_SINGLE_HOP_EXITS,    NO_ARGS, NO_OBJ ),

  T01("family",              K_FAMILY,              ARGS,    NO_OBJ ),
  T01("caches-extra-info",   K_CACHES_EXTRA_INFO,   NO_ARGS, NO_OBJ ),
  T0N("or-address",          K_OR_ADDRESS,          GE(1),   NO_OBJ ),

  T0N("opt",                 K_OPT,             CONCAT_ARGS, OBJ_OK ),
  T1( "bandwidth",           K_BANDWIDTH,           GE(3),   NO_OBJ ),
  A01("@purpose",            A_PURPOSE,             GE(1),   NO_OBJ ),
  T01("tunnelled-dir-server",K_DIR_TUNNELLED,       NO_ARGS, NO_OBJ ),

  END_OF_TABLE
};

/** List of tokens recognized in extra-info documents. */
static token_rule_t extrainfo_token_table[] = {
  T1_END( "router-signature",    K_ROUTER_SIGNATURE,    NO_ARGS, NEED_OBJ ),
  T1( "published",           K_PUBLISHED,       CONCAT_ARGS, NO_OBJ ),
  T01("identity-ed25519",    K_IDENTITY_ED25519,    NO_ARGS, NEED_OBJ ),
  T01("router-sig-ed25519",  K_ROUTER_SIG_ED25519,  GE(1),   NO_OBJ ),
  T0N("opt",                 K_OPT,             CONCAT_ARGS, OBJ_OK ),
  T01("read-history",        K_READ_HISTORY,        ARGS,    NO_OBJ ),
  T01("write-history",       K_WRITE_HISTORY,       ARGS,    NO_OBJ ),
  T01("dirreq-stats-end",    K_DIRREQ_END,          ARGS,    NO_OBJ ),
  T01("dirreq-v2-ips",       K_DIRREQ_V2_IPS,       ARGS,    NO_OBJ ),
  T01("dirreq-v3-ips",       K_DIRREQ_V3_IPS,       ARGS,    NO_OBJ ),
  T01("dirreq-v2-reqs",      K_DIRREQ_V2_REQS,      ARGS,    NO_OBJ ),
  T01("dirreq-v3-reqs",      K_DIRREQ_V3_REQS,      ARGS,    NO_OBJ ),
  T01("dirreq-v2-share",     K_DIRREQ_V2_SHARE,     ARGS,    NO_OBJ ),
  T01("dirreq-v3-share",     K_DIRREQ_V3_SHARE,     ARGS,    NO_OBJ ),
  T01("dirreq-v2-resp",      K_DIRREQ_V2_RESP,      ARGS,    NO_OBJ ),
  T01("dirreq-v3-resp",      K_DIRREQ_V3_RESP,      ARGS,    NO_OBJ ),
  T01("dirreq-v2-direct-dl", K_DIRREQ_V2_DIR,       ARGS,    NO_OBJ ),
  T01("dirreq-v3-direct-dl", K_DIRREQ_V3_DIR,       ARGS,    NO_OBJ ),
  T01("dirreq-v2-tunneled-dl", K_DIRREQ_V2_TUN,     ARGS,    NO_OBJ ),
  T01("dirreq-v3-tunneled-dl", K_DIRREQ_V3_TUN,     ARGS,    NO_OBJ ),
  T01("entry-stats-end",     K_ENTRY_END,           ARGS,    NO_OBJ ),
  T01("entry-ips",           K_ENTRY_IPS,           ARGS,    NO_OBJ ),
  T01("cell-stats-end",      K_CELL_END,            ARGS,    NO_OBJ ),
  T01("cell-processed-cells", K_CELL_PROCESSED,     ARGS,    NO_OBJ ),
  T01("cell-queued-cells",   K_CELL_QUEUED,         ARGS,    NO_OBJ ),
  T01("cell-time-in-queue",  K_CELL_TIME,           ARGS,    NO_OBJ ),
  T01("cell-circuits-per-decile", K_CELL_CIRCS,     ARGS,    NO_OBJ ),
  T01("exit-stats-end",      K_EXIT_END,            ARGS,    NO_OBJ ),
  T01("exit-kibibytes-written", K_EXIT_WRITTEN,     ARGS,    NO_OBJ ),
  T01("exit-kibibytes-read", K_EXIT_READ,           ARGS,    NO_OBJ ),
  T01("exit-streams-opened", K_EXIT_OPENED,         ARGS,    NO_OBJ ),

  T1_START( "extra-info",          K_EXTRA_INFO,          GE(2),   NO_OBJ ),

  END_OF_TABLE
};

/** List of tokens recognized in the body part of v3 networkstatus
 * documents. */
static token_rule_t rtrstatus_token_table[] = {
  T01("p",                   K_P,               CONCAT_ARGS, NO_OBJ ),
  T1( "r",                   K_R,                   GE(7),   NO_OBJ ),
  T0N("a",                   K_A,                   GE(1),   NO_OBJ ),
  T1( "s",                   K_S,                   ARGS,    NO_OBJ ),
  T01("v",                   K_V,               CONCAT_ARGS, NO_OBJ ),
  T01("w",                   K_W,                   ARGS,    NO_OBJ ),
  T0N("m",                   K_M,               CONCAT_ARGS, NO_OBJ ),
  T0N("id",                  K_ID,                  GE(2),   NO_OBJ ),
  T01("pr",                  K_PROTO,           CONCAT_ARGS, NO_OBJ ),
  T0N("opt",                 K_OPT,             CONCAT_ARGS, OBJ_OK ),
  END_OF_TABLE
};

/** List of tokens recognized in V3 networkstatus votes. */
static token_rule_t networkstatus_token_table[] = {
  T1_START("network-status-version", K_NETWORK_STATUS_VERSION,
                                                   GE(1),       NO_OBJ ),
  T1("vote-status",            K_VOTE_STATUS,      GE(1),       NO_OBJ ),
  T1("published",              K_PUBLISHED,        CONCAT_ARGS, NO_OBJ ),
  T1("valid-after",            K_VALID_AFTER,      CONCAT_ARGS, NO_OBJ ),
  T1("fresh-until",            K_FRESH_UNTIL,      CONCAT_ARGS, NO_OBJ ),
  T1("valid-until",            K_VALID_UNTIL,      CONCAT_ARGS, NO_OBJ ),
  T1("voting-delay",           K_VOTING_DELAY,     GE(2),       NO_OBJ ),
  T1("known-flags",            K_KNOWN_FLAGS,      ARGS,        NO_OBJ ),
  T01("params",                K_PARAMS,           ARGS,        NO_OBJ ),
  T( "fingerprint",            K_FINGERPRINT,      CONCAT_ARGS, NO_OBJ ),
  T01("signing-ed25519",       K_SIGNING_CERT_ED,  NO_ARGS ,    NEED_OBJ ),
  T01("shared-rand-participate",K_SR_FLAG,         NO_ARGS,     NO_OBJ ),
  T0N("shared-rand-commit",    K_COMMIT,           GE(3),       NO_OBJ ),
  T01("shared-rand-previous-value", K_PREVIOUS_SRV,EQ(2),       NO_OBJ ),
  T01("shared-rand-current-value",  K_CURRENT_SRV, EQ(2),       NO_OBJ ),
  T0N("package",               K_PACKAGE,          CONCAT_ARGS, NO_OBJ ),
  T01("recommended-client-protocols", K_RECOMMENDED_CLIENT_PROTOCOLS,
      CONCAT_ARGS, NO_OBJ ),
  T01("recommended-relay-protocols", K_RECOMMENDED_RELAY_PROTOCOLS,
      CONCAT_ARGS, NO_OBJ ),
  T01("required-client-protocols",    K_REQUIRED_CLIENT_PROTOCOLS,
      CONCAT_ARGS, NO_OBJ ),
  T01("required-relay-protocols",    K_REQUIRED_RELAY_PROTOCOLS,
      CONCAT_ARGS, NO_OBJ ),

#include "feature/dirparse/authcert_members.i"

  T0N("opt",                 K_OPT,             CONCAT_ARGS, OBJ_OK ),
  T1( "contact",             K_CONTACT,         CONCAT_ARGS, NO_OBJ ),
  T1( "dir-source",          K_DIR_SOURCE,      GE(6),       NO_OBJ ),
  T01("legacy-dir-key",      K_LEGACY_DIR_KEY,  GE(1),       NO_OBJ ),
  T1( "known-flags",         K_KNOWN_FLAGS,     CONCAT_ARGS, NO_OBJ ),
  T01("client-versions",     K_CLIENT_VERSIONS, CONCAT_ARGS, NO_OBJ ),
  T01("server-versions",     K_SERVER_VERSIONS, CONCAT_ARGS, NO_OBJ ),
  T1( "consensus-methods",   K_CONSENSUS_METHODS, GE(1),     NO_OBJ ),

  END_OF_TABLE
};

/** List of tokens recognized in V3 networkstatus consensuses. */
static token_rule_t networkstatus_consensus_token_table[] = {
  T1_START("network-status-version", K_NETWORK_STATUS_VERSION,
                                                   GE(1),       NO_OBJ ),
  T1("vote-status",            K_VOTE_STATUS,      GE(1),       NO_OBJ ),
  T1("valid-after",            K_VALID_AFTER,      CONCAT_ARGS, NO_OBJ ),
  T1("fresh-until",            K_FRESH_UNTIL,      CONCAT_ARGS, NO_OBJ ),
  T1("valid-until",            K_VALID_UNTIL,      CONCAT_ARGS, NO_OBJ ),
  T1("voting-delay",           K_VOTING_DELAY,     GE(2),       NO_OBJ ),

  T0N("opt",                 K_OPT,             CONCAT_ARGS, OBJ_OK ),

  T1N("dir-source",          K_DIR_SOURCE,          GE(6),   NO_OBJ ),
  T1N("contact",             K_CONTACT,         CONCAT_ARGS, NO_OBJ ),
  T1N("vote-digest",         K_VOTE_DIGEST,         GE(1),   NO_OBJ ),

  T1( "known-flags",         K_KNOWN_FLAGS,     CONCAT_ARGS, NO_OBJ ),

  T01("client-versions",     K_CLIENT_VERSIONS, CONCAT_ARGS, NO_OBJ ),
  T01("server-versions",     K_SERVER_VERSIONS, CONCAT_ARGS, NO_OBJ ),
  T01("consensus-method",    K_CONSENSUS_METHOD,    EQ(1),   NO_OBJ),
  T01("params",                K_PARAMS,           ARGS,        NO_OBJ ),

  T01("shared-rand-previous-value", K_PREVIOUS_SRV, EQ(2),   NO_OBJ ),
  T01("shared-rand-current-value",  K_CURRENT_SRV,  EQ(2),   NO_OBJ ),

  T01("recommended-client-protocols", K_RECOMMENDED_CLIENT_PROTOCOLS,
      CONCAT_ARGS, NO_OBJ ),
  T01("recommended-relay-protocols", K_RECOMMENDED_RELAY_PROTOCOLS,
      CONCAT_ARGS, NO_OBJ ),
  T01("required-client-protocols",    K_REQUIRED_CLIENT_PROTOCOLS,
      CONCAT_ARGS, NO_OBJ ),
  T01("required-relay-protocols",    K_REQUIRED_RELAY_PROTOCOLS,
      CONCAT_ARGS, NO_OBJ ),

  END_OF_TABLE
};

/** List of tokens recognized in the footer of v1 directory footers. */
static token_rule_t networkstatus_vote_footer_token_table[] = {
  T01("directory-footer",    K_DIRECTORY_FOOTER,    NO_ARGS,   NO_OBJ ),
  T01("bandwidth-weights",   K_BW_WEIGHTS,          ARGS,      NO_OBJ ),
  T(  "directory-signature", K_DIRECTORY_SIGNATURE, GE(2),     NEED_OBJ ),
  END_OF_TABLE
};

/** List of tokens recognized in detached networkstatus signature documents. */
static token_rule_t networkstatus_detached_signature_token_table[] = {
  T1_START("consensus-digest", K_CONSENSUS_DIGEST, GE(1),       NO_OBJ ),
  T("additional-digest",       K_ADDITIONAL_DIGEST,GE(3),       NO_OBJ ),
  T1("valid-after",            K_VALID_AFTER,      CONCAT_ARGS, NO_OBJ ),
  T1("fresh-until",            K_FRESH_UNTIL,      CONCAT_ARGS, NO_OBJ ),
  T1("valid-until",            K_VALID_UNTIL,      CONCAT_ARGS, NO_OBJ ),
  T("additional-signature",  K_ADDITIONAL_SIGNATURE, GE(4),   NEED_OBJ ),
  T1N("directory-signature", K_DIRECTORY_SIGNATURE,  GE(2),   NEED_OBJ ),
  END_OF_TABLE
};

#undef T

/* static function prototypes */
static int router_add_exit_policy(routerinfo_t *router,directory_token_t *tok);
static addr_policy_t *router_parse_addr_policy(directory_token_t *tok,
                                               unsigned fmt_flags);
static addr_policy_t *router_parse_addr_policy_private(directory_token_t *tok);

static smartlist_t *find_all_exitpolicy(smartlist_t *s);

/** Set <b>digest</b> to the SHA-1 digest of the hash of the first router in
 * <b>s</b>. Return 0 on success, -1 on failure.
 */
int
router_get_router_hash(const char *s, size_t s_len, char *digest)
{
  return router_get_hash_impl(s, s_len, digest,
                              "router ","\nrouter-signature", '\n',
                              DIGEST_SHA1);
}

/** Try to find the start and end of the signed portion of a networkstatus
 * document in <b>s</b>. On success, set <b>start_out</b> to the first
 * character of the document, and <b>end_out</b> to a position one after the
 * final character of the signed document, and return 0.  On failure, return
 * -1. */
int
router_get_networkstatus_v3_signed_boundaries(const char *s,
                                              const char **start_out,
                                              const char **end_out)
{
  return router_get_hash_impl_helper(s, strlen(s),
                                     "network-status-version",
                                     "\ndirectory-signature",
                                     ' ', LOG_INFO,
                                     start_out, end_out);
}

/** Set <b>digest_out</b> to the SHA3-256 digest of the signed portion of the
 * networkstatus vote in <b>s</b> -- or of the entirety of <b>s</b> if no
 * signed portion can be identified.  Return 0 on success, -1 on failure. */
int
router_get_networkstatus_v3_sha3_as_signed(uint8_t *digest_out,
                                           const char *s)
{
  const char *start, *end;
  if (router_get_networkstatus_v3_signed_boundaries(s, &start, &end) < 0) {
    start = s;
    end = s + strlen(s);
  }
  tor_assert(start);
  tor_assert(end);
  return crypto_digest256((char*)digest_out, start, end-start,
                          DIGEST_SHA3_256);
}

/** Set <b>digests</b> to all the digests of the consensus document in
 * <b>s</b> */
int
router_get_networkstatus_v3_hashes(const char *s, common_digests_t *digests)
{
  return router_get_hashes_impl(s,strlen(s),digests,
                                "network-status-version",
                                "\ndirectory-signature",
                                ' ');
}

/** Set <b>digest</b> to the SHA-1 digest of the hash of the <b>s_len</b>-byte
 * extrainfo string at <b>s</b>.  Return 0 on success, -1 on failure. */
int
router_get_extrainfo_hash(const char *s, size_t s_len, char *digest)
{
  return router_get_hash_impl(s, s_len, digest, "extra-info",
                              "\nrouter-signature",'\n', DIGEST_SHA1);
}

/** Helper: move *<b>s_ptr</b> ahead to the next router, the next extra-info,
 * or to the first of the annotations proceeding the next router or
 * extra-info---whichever comes first.  Set <b>is_extrainfo_out</b> to true if
 * we found an extrainfo, or false if found a router. Do not scan beyond
 * <b>eos</b>.  Return -1 if we found nothing; 0 if we found something. */
static int
find_start_of_next_router_or_extrainfo(const char **s_ptr,
                                       const char *eos,
                                       int *is_extrainfo_out)
{
  const char *annotations = NULL;
  const char *s = *s_ptr;

  s = eat_whitespace_eos(s, eos);

  while (s < eos-32) {  /* 32 gives enough room for a the first keyword. */
    /* We're at the start of a line. */
    tor_assert(*s != '\n');

    if (*s == '@' && !annotations) {
      annotations = s;
    } else if (*s == 'r' && !strcmpstart(s, "router ")) {
      *s_ptr = annotations ? annotations : s;
      *is_extrainfo_out = 0;
      return 0;
    } else if (*s == 'e' && !strcmpstart(s, "extra-info ")) {
      *s_ptr = annotations ? annotations : s;
      *is_extrainfo_out = 1;
      return 0;
    }

    if (!(s = memchr(s+1, '\n', eos-(s+1))))
      break;
    s = eat_whitespace_eos(s, eos);
  }
  return -1;
}

/** Given a string *<b>s</b> containing a concatenated sequence of router
 * descriptors (or extra-info documents if <b>want_extrainfo</b> is set),
 * parses them and stores the result in <b>dest</b>. All routers are marked
 * running and valid. Advances *s to a point immediately following the last
 * router entry. Ignore any trailing router entries that are not complete.
 *
 * If <b>saved_location</b> isn't SAVED_IN_CACHE, make a local copy of each
 * descriptor in the signed_descriptor_body field of each routerinfo_t.  If it
 * isn't SAVED_NOWHERE, remember the offset of each descriptor.
 *
 * Returns 0 on success and -1 on failure.  Adds a digest to
 * <b>invalid_digests_out</b> for every entry that was unparseable or
 * invalid. (This may cause duplicate entries.)
 */
int
router_parse_list_from_string(const char **s, const char *eos,
                              smartlist_t *dest,
                              saved_location_t saved_location,
                              int want_extrainfo,
                              int allow_annotations,
                              const char *prepend_annotations,
                              smartlist_t *invalid_digests_out)
{
  routerinfo_t *router;
  extrainfo_t *extrainfo;
  signed_descriptor_t *signed_desc = NULL;
  void *elt;
  const char *end, *start;
  int have_extrainfo;

  tor_assert(s);
  tor_assert(*s);
  tor_assert(dest);

  start = *s;
  if (!eos)
    eos = *s + strlen(*s);

  tor_assert(eos >= *s);

  while (1) {
    char raw_digest[DIGEST_LEN];
    int have_raw_digest = 0;
    int dl_again = 0;
    if (find_start_of_next_router_or_extrainfo(s, eos, &have_extrainfo) < 0)
      break;

    end = tor_memstr(*s, eos-*s, "\nrouter-signature");
    if (end)
      end = tor_memstr(end, eos-end, "\n-----END SIGNATURE-----\n");
    if (end)
      end += strlen("\n-----END SIGNATURE-----\n");

    if (!end)
      break;

    elt = NULL;

    if (have_extrainfo && want_extrainfo) {
      routerlist_t *rl = router_get_routerlist();
      have_raw_digest = router_get_extrainfo_hash(*s, end-*s, raw_digest) == 0;
      extrainfo = extrainfo_parse_entry_from_string(*s, end,
                                       saved_location != SAVED_IN_CACHE,
                                       rl->identity_map, &dl_again);
      if (extrainfo) {
        signed_desc = &extrainfo->cache_info;
        elt = extrainfo;
      }
    } else if (!have_extrainfo && !want_extrainfo) {
      have_raw_digest = router_get_router_hash(*s, end-*s, raw_digest) == 0;
      router = router_parse_entry_from_string(*s, end,
                                              saved_location != SAVED_IN_CACHE,
                                              allow_annotations,
                                              prepend_annotations, &dl_again);
      if (router) {
        log_debug(LD_DIR, "Read router '%s', purpose '%s'",
                  router_describe(router),
                  router_purpose_to_string(router->purpose));
        signed_desc = &router->cache_info;
        elt = router;
      }
    }
    if (! elt && ! dl_again && have_raw_digest && invalid_digests_out) {
      smartlist_add(invalid_digests_out, tor_memdup(raw_digest, DIGEST_LEN));
    }
    if (!elt) {
      *s = end;
      continue;
    }
    if (saved_location != SAVED_NOWHERE) {
      tor_assert(signed_desc);
      signed_desc->saved_location = saved_location;
      signed_desc->saved_offset = *s - start;
    }
    *s = end;
    smartlist_add(dest, elt);
  }

  return 0;
}

/** Try to find an IPv6 OR port in <b>list</b> of directory_token_t's
 * with at least one argument (use GE(1) in setup). If found, store
 * address and port number to <b>addr_out</b> and
 * <b>port_out</b>. Return number of OR ports found. */
int
find_single_ipv6_orport(const smartlist_t *list,
                        tor_addr_t *addr_out,
                        uint16_t *port_out)
{
  int ret = 0;
  tor_assert(list != NULL);
  tor_assert(addr_out != NULL);
  tor_assert(port_out != NULL);

  SMARTLIST_FOREACH_BEGIN(list, directory_token_t *, t) {
    tor_addr_t a;
    maskbits_t bits;
    uint16_t port_min, port_max;
    tor_assert(t->n_args >= 1);
    /* XXXX Prop186 the full spec allows much more than this. */
    if (tor_addr_parse_mask_ports(t->args[0], 0,
                                  &a, &bits, &port_min,
                                  &port_max) == AF_INET6 &&
        bits == 128 &&
        port_min == port_max) {
      /* Okay, this is one we can understand. Use it and ignore
         any potential more addresses in list. */
      tor_addr_copy(addr_out, &a);
      *port_out = port_min;
      ret = 1;
      break;
    }
  } SMARTLIST_FOREACH_END(t);

  return ret;
}

/** Helper function: reads a single router entry from *<b>s</b> ...
 * *<b>end</b>.  Mallocs a new router and returns it if all goes well, else
 * returns NULL.  If <b>cache_copy</b> is true, duplicate the contents of
 * s through end into the signed_descriptor_body of the resulting
 * routerinfo_t.
 *
 * If <b>end</b> is NULL, <b>s</b> must be properly NUL-terminated.
 *
 * If <b>allow_annotations</b>, it's okay to encounter annotations in <b>s</b>
 * before the router; if it's false, reject the router if it's annotated.  If
 * <b>prepend_annotations</b> is set, it should contain some annotations:
 * append them to the front of the router before parsing it, and keep them
 * around when caching the router.
 *
 * Only one of allow_annotations and prepend_annotations may be set.
 *
 * If <b>can_dl_again_out</b> is provided, set *<b>can_dl_again_out</b> to 1
 * if it's okay to try to download a descriptor with this same digest again,
 * and 0 if it isn't.  (It might not be okay to download it again if part of
 * the part covered by the digest is invalid.)
 */
routerinfo_t *
router_parse_entry_from_string(const char *s, const char *end,
                               int cache_copy, int allow_annotations,
                               const char *prepend_annotations,
                               int *can_dl_again_out)
{
  routerinfo_t *router = NULL;
  char digest[128];
  smartlist_t *tokens = NULL, *exit_policy_tokens = NULL;
  directory_token_t *tok;
  struct in_addr in;
  const char *start_of_annotations, *cp, *s_dup = s;
  size_t prepend_len = prepend_annotations ? strlen(prepend_annotations) : 0;
  int ok = 1;
  memarea_t *area = NULL;
  tor_cert_t *ntor_cc_cert = NULL;
  /* Do not set this to '1' until we have parsed everything that we intend to
   * parse that's covered by the hash. */
  int can_dl_again = 0;
  crypto_pk_t *rsa_pubkey = NULL;

  tor_assert(!allow_annotations || !prepend_annotations);

  if (!end) {
    end = s + strlen(s);
  }

  /* point 'end' to a point immediately after the final newline. */
  while (end > s+2 && *(end-1) == '\n' && *(end-2) == '\n')
    --end;

  area = memarea_new();
  tokens = smartlist_new();
  if (prepend_annotations) {
    if (tokenize_string(area,prepend_annotations,NULL,tokens,
                        routerdesc_token_table,TS_NOCHECK)) {
      log_warn(LD_DIR, "Error tokenizing router descriptor (annotations).");
      goto err;
    }
  }

  start_of_annotations = s;
  cp = tor_memstr(s, end-s, "\nrouter ");
  if (!cp) {
    if (end-s < 7 || strcmpstart(s, "router ")) {
      log_warn(LD_DIR, "No router keyword found.");
      goto err;
    }
  } else {
    s = cp+1;
  }

  if (start_of_annotations != s) { /* We have annotations */
    if (allow_annotations) {
      if (tokenize_string(area,start_of_annotations,s,tokens,
                          routerdesc_token_table,TS_NOCHECK)) {
        log_warn(LD_DIR, "Error tokenizing router descriptor (annotations).");
        goto err;
      }
    } else {
      log_warn(LD_DIR, "Found unexpected annotations on router descriptor not "
               "loaded from disk.  Dropping it.");
      goto err;
    }
  }

  if (router_get_router_hash(s, end - s, digest) < 0) {
    log_warn(LD_DIR, "Couldn't compute router hash.");
    goto err;
  }
  {
    int flags = 0;
    if (allow_annotations)
      flags |= TS_ANNOTATIONS_OK;
    if (prepend_annotations)
      flags |= TS_ANNOTATIONS_OK|TS_NO_NEW_ANNOTATIONS;

    if (tokenize_string(area,s,end,tokens,routerdesc_token_table, flags)) {
      log_warn(LD_DIR, "Error tokenizing router descriptor.");
      goto err;
    }
  }

  if (smartlist_len(tokens) < 2) {
    log_warn(LD_DIR, "Impossibly short router descriptor.");
    goto err;
  }

  tok = find_by_keyword(tokens, K_ROUTER);
  const int router_token_pos = smartlist_pos(tokens, tok);
  tor_assert(tok->n_args >= 5);

  router = tor_malloc_zero(sizeof(routerinfo_t));
  router->cert_expiration_time = TIME_MAX;
  router->cache_info.routerlist_index = -1;
  router->cache_info.annotations_len = s-start_of_annotations + prepend_len;
  router->cache_info.signed_descriptor_len = end-s;
  if (cache_copy) {
    size_t len = router->cache_info.signed_descriptor_len +
                 router->cache_info.annotations_len;
    char *signed_body =
      router->cache_info.signed_descriptor_body = tor_malloc(len+1);
    if (prepend_annotations) {
      memcpy(signed_body, prepend_annotations, prepend_len);
      signed_body += prepend_len;
    }
    /* This assertion will always succeed.
     * len == signed_desc_len + annotations_len
     *     == end-s + s-start_of_annotations + prepend_len
     *     == end-start_of_annotations + prepend_len
     * We already wrote prepend_len bytes into the buffer; now we're
     * writing end-start_of_annotations -NM. */
    tor_assert(signed_body+(end-start_of_annotations) ==
               router->cache_info.signed_descriptor_body+len);
    memcpy(signed_body, start_of_annotations, end-start_of_annotations);
    router->cache_info.signed_descriptor_body[len] = '\0';
    tor_assert(strlen(router->cache_info.signed_descriptor_body) == len);
  }
  memcpy(router->cache_info.signed_descriptor_digest, digest, DIGEST_LEN);

  router->nickname = tor_strdup(tok->args[0]);
  if (!is_legal_nickname(router->nickname)) {
    log_warn(LD_DIR,"Router nickname is invalid");
    goto err;
  }
  if (!tor_inet_aton(tok->args[1], &in)) {
    log_warn(LD_DIR,"Router address is not an IP address.");
    goto err;
  }
  router->addr = ntohl(in.s_addr);

  router->or_port =
    (uint16_t) tor_parse_long(tok->args[2],10,0,65535,&ok,NULL);
  if (!ok) {
    log_warn(LD_DIR,"Invalid OR port %s", escaped(tok->args[2]));
    goto err;
  }
  router->dir_port =
    (uint16_t) tor_parse_long(tok->args[4],10,0,65535,&ok,NULL);
  if (!ok) {
    log_warn(LD_DIR,"Invalid dir port %s", escaped(tok->args[4]));
    goto err;
  }

  tok = find_by_keyword(tokens, K_BANDWIDTH);
  tor_assert(tok->n_args >= 3);
  router->bandwidthrate = (int)
    tor_parse_long(tok->args[0],10,1,INT_MAX,&ok,NULL);

  if (!ok) {
    log_warn(LD_DIR, "bandwidthrate %s unreadable or 0. Failing.",
             escaped(tok->args[0]));
    goto err;
  }
  router->bandwidthburst =
    (int) tor_parse_long(tok->args[1],10,0,INT_MAX,&ok,NULL);
  if (!ok) {
    log_warn(LD_DIR, "Invalid bandwidthburst %s", escaped(tok->args[1]));
    goto err;
  }
  router->bandwidthcapacity = (int)
    tor_parse_long(tok->args[2],10,0,INT_MAX,&ok,NULL);
  if (!ok) {
    log_warn(LD_DIR, "Invalid bandwidthcapacity %s", escaped(tok->args[1]));
    goto err;
  }

  if ((tok = find_opt_by_keyword(tokens, A_PURPOSE))) {
    tor_assert(tok->n_args);
    router->purpose = router_purpose_from_string(tok->args[0]);
  } else {
    router->purpose = ROUTER_PURPOSE_GENERAL;
  }
  router->cache_info.send_unencrypted =
    (router->purpose == ROUTER_PURPOSE_GENERAL) ? 1 : 0;

  if ((tok = find_opt_by_keyword(tokens, K_UPTIME))) {
    tor_assert(tok->n_args >= 1);
    router->uptime = tor_parse_long(tok->args[0],10,0,LONG_MAX,&ok,NULL);
    if (!ok) {
      log_warn(LD_DIR, "Invalid uptime %s", escaped(tok->args[0]));
      goto err;
    }
  }

  if ((tok = find_opt_by_keyword(tokens, K_HIBERNATING))) {
    tor_assert(tok->n_args >= 1);
    router->is_hibernating
      = (tor_parse_long(tok->args[0],10,0,LONG_MAX,NULL,NULL) != 0);
  }

  tok = find_by_keyword(tokens, K_PUBLISHED);
  tor_assert(tok->n_args == 1);
  if (parse_iso_time(tok->args[0], &router->cache_info.published_on) < 0)
    goto err;

  tok = find_by_keyword(tokens, K_ONION_KEY);
  if (!crypto_pk_public_exponent_ok(tok->key)) {
    log_warn(LD_DIR,
             "Relay's onion key had invalid exponent.");
    goto err;
  }
  router_set_rsa_onion_pkey(tok->key, &router->onion_pkey,
                            &router->onion_pkey_len);
  crypto_pk_free(tok->key);

  if ((tok = find_opt_by_keyword(tokens, K_ONION_KEY_NTOR))) {
    curve25519_public_key_t k;
    tor_assert(tok->n_args >= 1);
    if (curve25519_public_from_base64(&k, tok->args[0]) < 0) {
      log_warn(LD_DIR, "Bogus ntor-onion-key in routerinfo");
      goto err;
    }
    router->onion_curve25519_pkey =
      tor_memdup(&k, sizeof(curve25519_public_key_t));
  }

  tok = find_by_keyword(tokens, K_SIGNING_KEY);
  router->identity_pkey = tok->key;
  tok->key = NULL; /* Prevent free */
  if (crypto_pk_get_digest(router->identity_pkey,
                           router->cache_info.identity_digest)) {
    log_warn(LD_DIR, "Couldn't calculate key digest"); goto err;
  }

  {
    directory_token_t *ed_sig_tok, *ed_cert_tok, *cc_tap_tok, *cc_ntor_tok,
      *master_key_tok;
    ed_sig_tok = find_opt_by_keyword(tokens, K_ROUTER_SIG_ED25519);
    ed_cert_tok = find_opt_by_keyword(tokens, K_IDENTITY_ED25519);
    master_key_tok = find_opt_by_keyword(tokens, K_MASTER_KEY_ED25519);
    cc_tap_tok = find_opt_by_keyword(tokens, K_ONION_KEY_CROSSCERT);
    cc_ntor_tok = find_opt_by_keyword(tokens, K_NTOR_ONION_KEY_CROSSCERT);
    int n_ed_toks = !!ed_sig_tok + !!ed_cert_tok +
      !!cc_tap_tok + !!cc_ntor_tok;
    if ((n_ed_toks != 0 && n_ed_toks != 4) ||
        (n_ed_toks == 4 && !router->onion_curve25519_pkey)) {
      log_warn(LD_DIR, "Router descriptor with only partial ed25519/"
               "cross-certification support");
      goto err;
    }
    if (master_key_tok && !ed_sig_tok) {
      log_warn(LD_DIR, "Router descriptor has ed25519 master key but no "
               "certificate");
      goto err;
    }
    if (ed_sig_tok) {
      tor_assert(ed_cert_tok && cc_tap_tok && cc_ntor_tok);
      const int ed_cert_token_pos = smartlist_pos(tokens, ed_cert_tok);
      if (ed_cert_token_pos == -1 || router_token_pos == -1 ||
          (ed_cert_token_pos != router_token_pos + 1 &&
           ed_cert_token_pos != router_token_pos - 1)) {
        log_warn(LD_DIR, "Ed25519 certificate in wrong position");
        goto err;
      }
      if (ed_sig_tok != smartlist_get(tokens, smartlist_len(tokens)-2)) {
        log_warn(LD_DIR, "Ed25519 signature in wrong position");
        goto err;
      }
      if (strcmp(ed_cert_tok->object_type, "ED25519 CERT")) {
        log_warn(LD_DIR, "Wrong object type on identity-ed25519 in decriptor");
        goto err;
      }
      if (strcmp(cc_ntor_tok->object_type, "ED25519 CERT")) {
        log_warn(LD_DIR, "Wrong object type on ntor-onion-key-crosscert "
                 "in decriptor");
        goto err;
      }
      if (strcmp(cc_tap_tok->object_type, "CROSSCERT")) {
        log_warn(LD_DIR, "Wrong object type on onion-key-crosscert "
                 "in decriptor");
        goto err;
      }
      if (strcmp(cc_ntor_tok->args[0], "0") &&
          strcmp(cc_ntor_tok->args[0], "1")) {
        log_warn(LD_DIR, "Bad sign bit on ntor-onion-key-crosscert");
        goto err;
      }
      int ntor_cc_sign_bit = !strcmp(cc_ntor_tok->args[0], "1");

      uint8_t d256[DIGEST256_LEN];
      const char *signed_start, *signed_end;
      tor_cert_t *cert = tor_cert_parse(
                       (const uint8_t*)ed_cert_tok->object_body,
                       ed_cert_tok->object_size);
      if (! cert) {
        log_warn(LD_DIR, "Couldn't parse ed25519 cert");
        goto err;
      }
      /* makes sure it gets freed. */
      router->cache_info.signing_key_cert = cert;

      if (cert->cert_type != CERT_TYPE_ID_SIGNING ||
          ! cert->signing_key_included) {
        log_warn(LD_DIR, "Invalid form for ed25519 cert");
        goto err;
      }

      if (master_key_tok) {
        /* This token is optional, but if it's present, it must match
         * the signature in the signing cert, or supplant it. */
        tor_assert(master_key_tok->n_args >= 1);
        ed25519_public_key_t pkey;
        if (ed25519_public_from_base64(&pkey, master_key_tok->args[0])<0) {
          log_warn(LD_DIR, "Can't parse ed25519 master key");
          goto err;
        }

        if (fast_memneq(&cert->signing_key.pubkey,
                        pkey.pubkey, ED25519_PUBKEY_LEN)) {
          log_warn(LD_DIR, "Ed25519 master key does not match "
                   "key in certificate");
          goto err;
        }
      }
      ntor_cc_cert = tor_cert_parse((const uint8_t*)cc_ntor_tok->object_body,
                                    cc_ntor_tok->object_size);
      if (!ntor_cc_cert) {
        log_warn(LD_DIR, "Couldn't parse ntor-onion-key-crosscert cert");
        goto err;
      }
      if (ntor_cc_cert->cert_type != CERT_TYPE_ONION_ID ||
          ! ed25519_pubkey_eq(&ntor_cc_cert->signed_key, &cert->signing_key)) {
        log_warn(LD_DIR, "Invalid contents for ntor-onion-key-crosscert cert");
        goto err;
      }

      ed25519_public_key_t ntor_cc_pk;
      if (ed25519_public_key_from_curve25519_public_key(&ntor_cc_pk,
                                            router->onion_curve25519_pkey,
                                            ntor_cc_sign_bit)<0) {
        log_warn(LD_DIR, "Error converting onion key to ed25519");
        goto err;
      }

      if (router_get_hash_impl_helper(s, end-s, "router ",
                                      "\nrouter-sig-ed25519",
                                      ' ', LOG_WARN,
                                      &signed_start, &signed_end) < 0) {
        log_warn(LD_DIR, "Can't find ed25519-signed portion of descriptor");
        goto err;
      }
      crypto_digest_t *d = crypto_digest256_new(DIGEST_SHA256);
      crypto_digest_add_bytes(d, ED_DESC_SIGNATURE_PREFIX,
        strlen(ED_DESC_SIGNATURE_PREFIX));
      crypto_digest_add_bytes(d, signed_start, signed_end-signed_start);
      crypto_digest_get_digest(d, (char*)d256, sizeof(d256));
      crypto_digest_free(d);

      ed25519_checkable_t check[3];
      int check_ok[3];
      time_t expires = TIME_MAX;
      if (tor_cert_get_checkable_sig(&check[0], cert, NULL, &expires) < 0) {
        log_err(LD_BUG, "Couldn't create 'checkable' for cert.");
        goto err;
      }
      if (tor_cert_get_checkable_sig(&check[1],
                               ntor_cc_cert, &ntor_cc_pk, &expires) < 0) {
        log_err(LD_BUG, "Couldn't create 'checkable' for ntor_cc_cert.");
        goto err;
      }

      if (ed25519_signature_from_base64(&check[2].signature,
                                        ed_sig_tok->args[0])<0) {
        log_warn(LD_DIR, "Couldn't decode ed25519 signature");
        goto err;
      }
      check[2].pubkey = &cert->signed_key;
      check[2].msg = d256;
      check[2].len = DIGEST256_LEN;

      if (ed25519_checksig_batch(check_ok, check, 3) < 0) {
        log_warn(LD_DIR, "Incorrect ed25519 signature(s)");
        goto err;
      }

      rsa_pubkey = router_get_rsa_onion_pkey(router->onion_pkey,
                                             router->onion_pkey_len);
      if (check_tap_onion_key_crosscert(
                      (const uint8_t*)cc_tap_tok->object_body,
                      (int)cc_tap_tok->object_size,
                      rsa_pubkey,
                      &cert->signing_key,
                      (const uint8_t*)router->cache_info.identity_digest)<0) {
        log_warn(LD_DIR, "Incorrect TAP cross-verification");
        goto err;
      }

      /* We check this before adding it to the routerlist. */
      router->cert_expiration_time = expires;
    }
  }

  if ((tok = find_opt_by_keyword(tokens, K_FINGERPRINT))) {
    /* If there's a fingerprint line, it must match the identity digest. */
    char d[DIGEST_LEN];
    tor_assert(tok->n_args == 1);
    tor_strstrip(tok->args[0], " ");
    if (base16_decode(d, DIGEST_LEN,
                      tok->args[0], strlen(tok->args[0])) != DIGEST_LEN) {
      log_warn(LD_DIR, "Couldn't decode router fingerprint %s",
               escaped(tok->args[0]));
      goto err;
    }
    if (tor_memneq(d,router->cache_info.identity_digest, DIGEST_LEN)) {
      log_warn(LD_DIR, "Fingerprint '%s' does not match identity digest.",
               tok->args[0]);
      goto err;
    }
  }

  {
    const char *version = NULL, *protocols = NULL;
    if ((tok = find_opt_by_keyword(tokens, K_PLATFORM))) {
      router->platform = tor_strdup(tok->args[0]);
      version = tok->args[0];
    }

    if ((tok = find_opt_by_keyword(tokens, K_PROTO))) {
      router->protocol_list = tor_strdup(tok->args[0]);
      protocols = tok->args[0];
    }

    summarize_protover_flags(&router->pv, protocols, version);
  }

  if ((tok = find_opt_by_keyword(tokens, K_CONTACT))) {
    router->contact_info = tor_strdup(tok->args[0]);
  }

  if (find_opt_by_keyword(tokens, K_REJECT6) ||
      find_opt_by_keyword(tokens, K_ACCEPT6)) {
    log_warn(LD_DIR, "Rejecting router with reject6/accept6 line: they crash "
             "older Tors.");
    goto err;
  }
  {
    smartlist_t *or_addresses = find_all_by_keyword(tokens, K_OR_ADDRESS);
    if (or_addresses) {
      find_single_ipv6_orport(or_addresses, &router->ipv6_addr,
                              &router->ipv6_orport);
      smartlist_free(or_addresses);
    }
  }
  exit_policy_tokens = find_all_exitpolicy(tokens);
  if (!smartlist_len(exit_policy_tokens)) {
    log_warn(LD_DIR, "No exit policy tokens in descriptor.");
    goto err;
  }
  SMARTLIST_FOREACH(exit_policy_tokens, directory_token_t *, t,
                    if (router_add_exit_policy(router,t)<0) {
                      log_warn(LD_DIR,"Error in exit policy");
                      goto err;
                    });
  policy_expand_private(&router->exit_policy);

  if ((tok = find_opt_by_keyword(tokens, K_IPV6_POLICY)) && tok->n_args) {
    router->ipv6_exit_policy = parse_short_policy(tok->args[0]);
    if (! router->ipv6_exit_policy) {
      log_warn(LD_DIR , "Error in ipv6-policy %s", escaped(tok->args[0]));
      goto err;
    }
  }

  if (policy_is_reject_star(router->exit_policy, AF_INET, 1) &&
      (!router->ipv6_exit_policy ||
       short_policy_is_reject_star(router->ipv6_exit_policy)))
    router->policy_is_reject_star = 1;

  if ((tok = find_opt_by_keyword(tokens, K_FAMILY)) && tok->n_args) {
    int i;
    router->declared_family = smartlist_new();
    for (i=0;i<tok->n_args;++i) {
      if (!is_legal_nickname_or_hexdigest(tok->args[i])) {
        log_warn(LD_DIR, "Illegal nickname %s in family line",
                 escaped(tok->args[i]));
        goto err;
      }
      smartlist_add_strdup(router->declared_family, tok->args[i]);
    }
  }

  if (find_opt_by_keyword(tokens, K_CACHES_EXTRA_INFO))
    router->caches_extra_info = 1;

  if (find_opt_by_keyword(tokens, K_ALLOW_SINGLE_HOP_EXITS))
    router->allow_single_hop_exits = 1;

  if ((tok = find_opt_by_keyword(tokens, K_EXTRA_INFO_DIGEST))) {
    tor_assert(tok->n_args >= 1);
    if (strlen(tok->args[0]) == HEX_DIGEST_LEN) {
      if (base16_decode(router->cache_info.extra_info_digest, DIGEST_LEN,
                        tok->args[0], HEX_DIGEST_LEN) != DIGEST_LEN) {
          log_warn(LD_DIR,"Invalid extra info digest");
      }
    } else {
      log_warn(LD_DIR, "Invalid extra info digest %s", escaped(tok->args[0]));
    }

    if (tok->n_args >= 2) {
      if (digest256_from_base64(router->cache_info.extra_info_digest256,
                                tok->args[1]) < 0) {
        log_warn(LD_DIR, "Invalid extra info digest256 %s",
                 escaped(tok->args[1]));
      }
    }
  }

  if (find_opt_by_keyword(tokens, K_HIDDEN_SERVICE_DIR)) {
    router->wants_to_be_hs_dir = 1;
  }

  /* This router accepts tunnelled directory requests via begindir if it has
   * an open dirport or it included "tunnelled-dir-server". */
  if (find_opt_by_keyword(tokens, K_DIR_TUNNELLED) || router->dir_port > 0) {
    router->supports_tunnelled_dir_requests = 1;
  }

  tok = find_by_keyword(tokens, K_ROUTER_SIGNATURE);

  if (!router->or_port) {
    log_warn(LD_DIR,"or_port unreadable or 0. Failing.");
    goto err;
  }

  /* We've checked everything that's covered by the hash. */
  can_dl_again = 1;
  if (check_signature_token(digest, DIGEST_LEN, tok, router->identity_pkey, 0,
                            "router descriptor") < 0)
    goto err;

  if (!router->platform) {
    router->platform = tor_strdup("<unknown>");
  }
  goto done;

 err:
  dump_desc(s_dup, "router descriptor");
  routerinfo_free(router);
  router = NULL;
 done:
  crypto_pk_free(rsa_pubkey);
  tor_cert_free(ntor_cc_cert);
  if (tokens) {
    SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
    smartlist_free(tokens);
  }
  smartlist_free(exit_policy_tokens);
  if (area) {
    DUMP_AREA(area, "routerinfo");
    memarea_drop_all(area);
  }
  if (can_dl_again_out)
    *can_dl_again_out = can_dl_again;
  return router;
}

/** Parse a single extrainfo entry from the string <b>s</b>, ending at
 * <b>end</b>.  (If <b>end</b> is NULL, parse up to the end of <b>s</b>.)  If
 * <b>cache_copy</b> is true, make a copy of the extra-info document in the
 * cache_info fields of the result.  If <b>routermap</b> is provided, use it
 * as a map from router identity to routerinfo_t when looking up signing keys.
 *
 * If <b>can_dl_again_out</b> is provided, set *<b>can_dl_again_out</b> to 1
 * if it's okay to try to download an extrainfo with this same digest again,
 * and 0 if it isn't.  (It might not be okay to download it again if part of
 * the part covered by the digest is invalid.)
 */
extrainfo_t *
extrainfo_parse_entry_from_string(const char *s, const char *end,
                            int cache_copy, struct digest_ri_map_t *routermap,
                            int *can_dl_again_out)
{
  extrainfo_t *extrainfo = NULL;
  char digest[128];
  smartlist_t *tokens = NULL;
  directory_token_t *tok;
  crypto_pk_t *key = NULL;
  routerinfo_t *router = NULL;
  memarea_t *area = NULL;
  const char *s_dup = s;
  /* Do not set this to '1' until we have parsed everything that we intend to
   * parse that's covered by the hash. */
  int can_dl_again = 0;

  if (BUG(s == NULL))
    return NULL;

  if (!end) {
    end = s + strlen(s);
  }

  /* point 'end' to a point immediately after the final newline. */
  while (end > s+2 && *(end-1) == '\n' && *(end-2) == '\n')
    --end;

  if (router_get_extrainfo_hash(s, end-s, digest) < 0) {
    log_warn(LD_DIR, "Couldn't compute router hash.");
    goto err;
  }
  tokens = smartlist_new();
  area = memarea_new();
  if (tokenize_string(area,s,end,tokens,extrainfo_token_table,0)) {
    log_warn(LD_DIR, "Error tokenizing extra-info document.");
    goto err;
  }

  if (smartlist_len(tokens) < 2) {
    log_warn(LD_DIR, "Impossibly short extra-info document.");
    goto err;
  }

  /* XXXX Accept this in position 1 too, and ed identity in position 0. */
  tok = smartlist_get(tokens,0);
  if (tok->tp != K_EXTRA_INFO) {
    log_warn(LD_DIR,"Entry does not start with \"extra-info\"");
    goto err;
  }

  extrainfo = tor_malloc_zero(sizeof(extrainfo_t));
  extrainfo->cache_info.is_extrainfo = 1;
  if (cache_copy)
    extrainfo->cache_info.signed_descriptor_body = tor_memdup_nulterm(s,end-s);
  extrainfo->cache_info.signed_descriptor_len = end-s;
  memcpy(extrainfo->cache_info.signed_descriptor_digest, digest, DIGEST_LEN);
  crypto_digest256((char*)extrainfo->digest256, s, end-s, DIGEST_SHA256);

  tor_assert(tok->n_args >= 2);
  if (!is_legal_nickname(tok->args[0])) {
    log_warn(LD_DIR,"Bad nickname %s on \"extra-info\"",escaped(tok->args[0]));
    goto err;
  }
  strlcpy(extrainfo->nickname, tok->args[0], sizeof(extrainfo->nickname));
  if (strlen(tok->args[1]) != HEX_DIGEST_LEN ||
      base16_decode(extrainfo->cache_info.identity_digest, DIGEST_LEN,
                    tok->args[1], HEX_DIGEST_LEN) != DIGEST_LEN) {
    log_warn(LD_DIR,"Invalid fingerprint %s on \"extra-info\"",
             escaped(tok->args[1]));
    goto err;
  }

  tok = find_by_keyword(tokens, K_PUBLISHED);
  if (parse_iso_time(tok->args[0], &extrainfo->cache_info.published_on)) {
    log_warn(LD_DIR,"Invalid published time %s on \"extra-info\"",
             escaped(tok->args[0]));
    goto err;
  }

  {
    directory_token_t *ed_sig_tok, *ed_cert_tok;
    ed_sig_tok = find_opt_by_keyword(tokens, K_ROUTER_SIG_ED25519);
    ed_cert_tok = find_opt_by_keyword(tokens, K_IDENTITY_ED25519);
    int n_ed_toks = !!ed_sig_tok + !!ed_cert_tok;
    if (n_ed_toks != 0 && n_ed_toks != 2) {
      log_warn(LD_DIR, "Router descriptor with only partial ed25519/"
               "cross-certification support");
      goto err;
    }
    if (ed_sig_tok) {
      tor_assert(ed_cert_tok);
      const int ed_cert_token_pos = smartlist_pos(tokens, ed_cert_tok);
      if (ed_cert_token_pos != 1) {
        /* Accept this in position 0 XXXX */
        log_warn(LD_DIR, "Ed25519 certificate in wrong position");
        goto err;
      }
      if (ed_sig_tok != smartlist_get(tokens, smartlist_len(tokens)-2)) {
        log_warn(LD_DIR, "Ed25519 signature in wrong position");
        goto err;
      }
      if (strcmp(ed_cert_tok->object_type, "ED25519 CERT")) {
        log_warn(LD_DIR, "Wrong object type on identity-ed25519 in decriptor");
        goto err;
      }

      uint8_t d256[DIGEST256_LEN];
      const char *signed_start, *signed_end;
      tor_cert_t *cert = tor_cert_parse(
                       (const uint8_t*)ed_cert_tok->object_body,
                       ed_cert_tok->object_size);
      if (! cert) {
        log_warn(LD_DIR, "Couldn't parse ed25519 cert");
        goto err;
      }
      /* makes sure it gets freed. */
      extrainfo->cache_info.signing_key_cert = cert;

      if (cert->cert_type != CERT_TYPE_ID_SIGNING ||
          ! cert->signing_key_included) {
        log_warn(LD_DIR, "Invalid form for ed25519 cert");
        goto err;
      }

      if (router_get_hash_impl_helper(s, end-s, "extra-info ",
                                      "\nrouter-sig-ed25519",
                                      ' ', LOG_WARN,
                                      &signed_start, &signed_end) < 0) {
        log_warn(LD_DIR, "Can't find ed25519-signed portion of extrainfo");
        goto err;
      }
      crypto_digest_t *d = crypto_digest256_new(DIGEST_SHA256);
      crypto_digest_add_bytes(d, ED_DESC_SIGNATURE_PREFIX,
        strlen(ED_DESC_SIGNATURE_PREFIX));
      crypto_digest_add_bytes(d, signed_start, signed_end-signed_start);
      crypto_digest_get_digest(d, (char*)d256, sizeof(d256));
      crypto_digest_free(d);

      ed25519_checkable_t check[2];
      int check_ok[2];
      if (tor_cert_get_checkable_sig(&check[0], cert, NULL, NULL) < 0) {
        log_err(LD_BUG, "Couldn't create 'checkable' for cert.");
        goto err;
      }

      if (ed25519_signature_from_base64(&check[1].signature,
                                        ed_sig_tok->args[0])<0) {
        log_warn(LD_DIR, "Couldn't decode ed25519 signature");
        goto err;
      }
      check[1].pubkey = &cert->signed_key;
      check[1].msg = d256;
      check[1].len = DIGEST256_LEN;

      if (ed25519_checksig_batch(check_ok, check, 2) < 0) {
        log_warn(LD_DIR, "Incorrect ed25519 signature(s)");
        goto err;
      }
      /* We don't check the certificate expiration time: checking that it
       * matches the cert in the router descriptor is adequate. */
    }
  }

  /* We've checked everything that's covered by the hash. */
  can_dl_again = 1;

  if (routermap &&
      (router = digestmap_get((digestmap_t*)routermap,
                              extrainfo->cache_info.identity_digest))) {
    key = router->identity_pkey;
  }

  tok = find_by_keyword(tokens, K_ROUTER_SIGNATURE);
  if (strcmp(tok->object_type, "SIGNATURE") ||
      tok->object_size < 128 || tok->object_size > 512) {
    log_warn(LD_DIR, "Bad object type or length on extra-info signature");
    goto err;
  }

  if (key) {
    if (check_signature_token(digest, DIGEST_LEN, tok, key, 0,
                              "extra-info") < 0)
      goto err;

    if (router)
      extrainfo->cache_info.send_unencrypted =
        router->cache_info.send_unencrypted;
  } else {
    extrainfo->pending_sig = tor_memdup(tok->object_body,
                                        tok->object_size);
    extrainfo->pending_sig_len = tok->object_size;
  }

  goto done;
 err:
  dump_desc(s_dup, "extra-info descriptor");
  extrainfo_free(extrainfo);
  extrainfo = NULL;
 done:
  if (tokens) {
    SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
    smartlist_free(tokens);
  }
  if (area) {
    DUMP_AREA(area, "extrainfo");
    memarea_drop_all(area);
  }
  if (can_dl_again_out)
    *can_dl_again_out = can_dl_again;
  return extrainfo;
}

/** Helper: given a string <b>s</b>, return the start of the next router-status
 * object (starting with "r " at the start of a line).  If none is found,
 * return the start of the directory footer, or the next directory signature.
 * If none is found, return the end of the string. */
static inline const char *
find_start_of_next_routerstatus(const char *s)
{
  const char *eos, *footer, *sig;
  if ((eos = strstr(s, "\nr ")))
    ++eos;
  else
    eos = s + strlen(s);

  footer = tor_memstr(s, eos-s, "\ndirectory-footer");
  sig = tor_memstr(s, eos-s, "\ndirectory-signature");

  if (footer && sig)
    return MIN(footer, sig) + 1;
  else if (footer)
    return footer+1;
  else if (sig)
    return sig+1;
  else
    return eos;
}

/** Parse the GuardFraction string from a consensus or vote.
 *
 *  If <b>vote</b> or <b>vote_rs</b> are set the document getting
 *  parsed is a vote routerstatus. Otherwise it's a consensus. This is
 *  the same semantic as in routerstatus_parse_entry_from_string(). */
STATIC int
routerstatus_parse_guardfraction(const char *guardfraction_str,
                                 networkstatus_t *vote,
                                 vote_routerstatus_t *vote_rs,
                                 routerstatus_t *rs)
{
  int ok;
  const char *end_of_header = NULL;
  int is_consensus = !vote_rs;
  uint32_t guardfraction;

  tor_assert(bool_eq(vote, vote_rs));

  /* If this info comes from a consensus, but we should't apply
     guardfraction, just exit. */
  if (is_consensus && !should_apply_guardfraction(NULL)) {
    return 0;
  }

  end_of_header = strchr(guardfraction_str, '=');
  if (!end_of_header) {
    return -1;
  }

  guardfraction = (uint32_t)tor_parse_ulong(end_of_header+1,
                                            10, 0, 100, &ok, NULL);
  if (!ok) {
    log_warn(LD_DIR, "Invalid GuardFraction %s", escaped(guardfraction_str));
    return -1;
  }

  log_debug(LD_GENERAL, "[*] Parsed %s guardfraction '%s' for '%s'.",
            is_consensus ? "consensus" : "vote",
            guardfraction_str, rs->nickname);

  if (!is_consensus) { /* We are parsing a vote */
    vote_rs->status.guardfraction_percentage = guardfraction;
    vote_rs->status.has_guardfraction = 1;
  } else {
    /* We are parsing a consensus. Only apply guardfraction to guards. */
    if (rs->is_possible_guard) {
      rs->guardfraction_percentage = guardfraction;
      rs->has_guardfraction = 1;
    } else {
      log_warn(LD_BUG, "Got GuardFraction for non-guard %s. "
               "This is not supposed to happen. Not applying. ", rs->nickname);
    }
  }

  return 0;
}

/** Summarize the protocols listed in <b>protocols</b> into <b>out</b>,
 * falling back or correcting them based on <b>version</b> as appropriate.
 */
STATIC void
summarize_protover_flags(protover_summary_flags_t *out,
                         const char *protocols,
                         const char *version)
{
  tor_assert(out);
  memset(out, 0, sizeof(*out));
  if (protocols) {
    out->protocols_known = 1;
    out->supports_extend2_cells =
      protocol_list_supports_protocol(protocols, PRT_RELAY, 2);
    out->supports_ed25519_link_handshake_compat =
      protocol_list_supports_protocol(protocols, PRT_LINKAUTH, 3);
    out->supports_ed25519_link_handshake_any =
      protocol_list_supports_protocol_or_later(protocols, PRT_LINKAUTH, 3);
    out->supports_ed25519_hs_intro =
      protocol_list_supports_protocol(protocols, PRT_HSINTRO, 4);
    out->supports_v3_hsdir =
      protocol_list_supports_protocol(protocols, PRT_HSDIR,
                                      PROTOVER_HSDIR_V3);
    out->supports_v3_rendezvous_point =
      protocol_list_supports_protocol(protocols, PRT_HSREND,
                                      PROTOVER_HS_RENDEZVOUS_POINT_V3);
  }
  if (version && !strcmpstart(version, "Tor ")) {
    if (!out->protocols_known) {
      /* The version is a "Tor" version, and where there is no
       * list of protocol versions that we should be looking at instead. */

      out->supports_extend2_cells =
        tor_version_as_new_as(version, "0.2.4.8-alpha");
      out->protocols_known = 1;
    } else {
      /* Bug #22447 forces us to filter on this version. */
      if (!tor_version_as_new_as(version, "0.3.0.8")) {
        out->supports_v3_hsdir = 0;
      }
    }
  }
}

/** Given a string at *<b>s</b>, containing a routerstatus object, and an
 * empty smartlist at <b>tokens</b>, parse and return the first router status
 * object in the string, and advance *<b>s</b> to just after the end of the
 * router status.  Return NULL and advance *<b>s</b> on error.
 *
 * If <b>vote</b> and <b>vote_rs</b> are provided, don't allocate a fresh
 * routerstatus but use <b>vote_rs</b> instead.
 *
 * If <b>consensus_method</b> is nonzero, this routerstatus is part of a
 * consensus, and we should parse it according to the method used to
 * make that consensus.
 *
 * Parse according to the syntax used by the consensus flavor <b>flav</b>.
 **/
STATIC routerstatus_t *
routerstatus_parse_entry_from_string(memarea_t *area,
                                     const char **s, smartlist_t *tokens,
                                     networkstatus_t *vote,
                                     vote_routerstatus_t *vote_rs,
                                     int consensus_method,
                                     consensus_flavor_t flav)
{
  const char *eos, *s_dup = *s;
  routerstatus_t *rs = NULL;
  directory_token_t *tok;
  char timebuf[ISO_TIME_LEN+1];
  struct in_addr in;
  int offset = 0;
  tor_assert(tokens);
  tor_assert(bool_eq(vote, vote_rs));

  if (!consensus_method)
    flav = FLAV_NS;
  tor_assert(flav == FLAV_NS || flav == FLAV_MICRODESC);

  eos = find_start_of_next_routerstatus(*s);

  if (tokenize_string(area,*s, eos, tokens, rtrstatus_token_table,0)) {
    log_warn(LD_DIR, "Error tokenizing router status");
    goto err;
  }
  if (smartlist_len(tokens) < 1) {
    log_warn(LD_DIR, "Impossibly short router status");
    goto err;
  }
  tok = find_by_keyword(tokens, K_R);
  tor_assert(tok->n_args >= 7); /* guaranteed by GE(7) in K_R setup */
  if (flav == FLAV_NS) {
    if (tok->n_args < 8) {
      log_warn(LD_DIR, "Too few arguments to r");
      goto err;
    }
  } else if (flav == FLAV_MICRODESC) {
    offset = -1; /* There is no descriptor digest in an md consensus r line */
  }

  if (vote_rs) {
    rs = &vote_rs->status;
  } else {
    rs = tor_malloc_zero(sizeof(routerstatus_t));
  }

  if (!is_legal_nickname(tok->args[0])) {
    log_warn(LD_DIR,
             "Invalid nickname %s in router status; skipping.",
             escaped(tok->args[0]));
    goto err;
  }
  strlcpy(rs->nickname, tok->args[0], sizeof(rs->nickname));

  if (digest_from_base64(rs->identity_digest, tok->args[1])) {
    log_warn(LD_DIR, "Error decoding identity digest %s",
             escaped(tok->args[1]));
    goto err;
  }

  if (flav == FLAV_NS) {
    if (digest_from_base64(rs->descriptor_digest, tok->args[2])) {
      log_warn(LD_DIR, "Error decoding descriptor digest %s",
               escaped(tok->args[2]));
      goto err;
    }
  }

  if (tor_snprintf(timebuf, sizeof(timebuf), "%s %s",
                   tok->args[3+offset], tok->args[4+offset]) < 0 ||
      parse_iso_time(timebuf, &rs->published_on)<0) {
    log_warn(LD_DIR, "Error parsing time '%s %s' [%d %d]",
             tok->args[3+offset], tok->args[4+offset],
             offset, (int)flav);
    goto err;
  }

  if (tor_inet_aton(tok->args[5+offset], &in) == 0) {
    log_warn(LD_DIR, "Error parsing router address in network-status %s",
             escaped(tok->args[5+offset]));
    goto err;
  }
  rs->addr = ntohl(in.s_addr);

  rs->or_port = (uint16_t) tor_parse_long(tok->args[6+offset],
                                         10,0,65535,NULL,NULL);
  rs->dir_port = (uint16_t) tor_parse_long(tok->args[7+offset],
                                           10,0,65535,NULL,NULL);

  {
    smartlist_t *a_lines = find_all_by_keyword(tokens, K_A);
    if (a_lines) {
      find_single_ipv6_orport(a_lines, &rs->ipv6_addr, &rs->ipv6_orport);
      smartlist_free(a_lines);
    }
  }

  tok = find_opt_by_keyword(tokens, K_S);
  if (tok && vote) {
    int i;
    vote_rs->flags = 0;
    for (i=0; i < tok->n_args; ++i) {
      int p = smartlist_string_pos(vote->known_flags, tok->args[i]);
      if (p >= 0) {
        vote_rs->flags |= (UINT64_C(1)<<p);
      } else {
        log_warn(LD_DIR, "Flags line had a flag %s not listed in known_flags.",
                 escaped(tok->args[i]));
        goto err;
      }
    }
  } else if (tok) {
    /* This is a consensus, not a vote. */
    int i;
    for (i=0; i < tok->n_args; ++i) {
      if (!strcmp(tok->args[i], "Exit"))
        rs->is_exit = 1;
      else if (!strcmp(tok->args[i], "Stable"))
        rs->is_stable = 1;
      else if (!strcmp(tok->args[i], "Fast"))
        rs->is_fast = 1;
      else if (!strcmp(tok->args[i], "Running"))
        rs->is_flagged_running = 1;
      else if (!strcmp(tok->args[i], "Named"))
        rs->is_named = 1;
      else if (!strcmp(tok->args[i], "Valid"))
        rs->is_valid = 1;
      else if (!strcmp(tok->args[i], "Guard"))
        rs->is_possible_guard = 1;
      else if (!strcmp(tok->args[i], "BadExit"))
        rs->is_bad_exit = 1;
      else if (!strcmp(tok->args[i], "Authority"))
        rs->is_authority = 1;
      else if (!strcmp(tok->args[i], "Unnamed") &&
               consensus_method >= 2) {
        /* Unnamed is computed right by consensus method 2 and later. */
        rs->is_unnamed = 1;
      } else if (!strcmp(tok->args[i], "HSDir")) {
        rs->is_hs_dir = 1;
      } else if (!strcmp(tok->args[i], "V2Dir")) {
        rs->is_v2_dir = 1;
      }
    }
    /* These are implied true by having been included in a consensus made
     * with a given method */
    rs->is_flagged_running = 1; /* Starting with consensus method 4. */
    rs->is_valid = 1; /* Starting with consensus method 24. */
  }
  {
    const char *protocols = NULL, *version = NULL;
    if ((tok = find_opt_by_keyword(tokens, K_PROTO))) {
      tor_assert(tok->n_args == 1);
      protocols = tok->args[0];
    }
    if ((tok = find_opt_by_keyword(tokens, K_V))) {
      tor_assert(tok->n_args == 1);
      version = tok->args[0];
      if (vote_rs) {
        vote_rs->version = tor_strdup(tok->args[0]);
      }
    }

    summarize_protover_flags(&rs->pv, protocols, version);
  }

  /* handle weighting/bandwidth info */
  if ((tok = find_opt_by_keyword(tokens, K_W))) {
    int i;
    for (i=0; i < tok->n_args; ++i) {
      if (!strcmpstart(tok->args[i], "Bandwidth=")) {
        int ok;
        rs->bandwidth_kb =
          (uint32_t)tor_parse_ulong(strchr(tok->args[i], '=')+1,
                                    10, 0, UINT32_MAX,
                                    &ok, NULL);
        if (!ok) {
          log_warn(LD_DIR, "Invalid Bandwidth %s", escaped(tok->args[i]));
          goto err;
        }
        rs->has_bandwidth = 1;
      } else if (!strcmpstart(tok->args[i], "Measured=") && vote_rs) {
        int ok;
        vote_rs->measured_bw_kb =
            (uint32_t)tor_parse_ulong(strchr(tok->args[i], '=')+1,
                                      10, 0, UINT32_MAX, &ok, NULL);
        if (!ok) {
          log_warn(LD_DIR, "Invalid Measured Bandwidth %s",
                   escaped(tok->args[i]));
          goto err;
        }
        vote_rs->has_measured_bw = 1;
        vote->has_measured_bws = 1;
      } else if (!strcmpstart(tok->args[i], "Unmeasured=1")) {
        rs->bw_is_unmeasured = 1;
      } else if (!strcmpstart(tok->args[i], "GuardFraction=")) {
        if (routerstatus_parse_guardfraction(tok->args[i],
                                             vote, vote_rs, rs) < 0) {
          goto err;
        }
      }
    }
  }

  /* parse exit policy summaries */
  if ((tok = find_opt_by_keyword(tokens, K_P))) {
    tor_assert(tok->n_args == 1);
    if (strcmpstart(tok->args[0], "accept ") &&
        strcmpstart(tok->args[0], "reject ")) {
      log_warn(LD_DIR, "Unknown exit policy summary type %s.",
               escaped(tok->args[0]));
      goto err;
    }
    /* XXX weasel: parse this into ports and represent them somehow smart,
     * maybe not here but somewhere on if we need it for the client.
     * we should still parse it here to check it's valid tho.
     */
    rs->exitsummary = tor_strdup(tok->args[0]);
    rs->has_exitsummary = 1;
  }

  if (vote_rs) {
    SMARTLIST_FOREACH_BEGIN(tokens, directory_token_t *, t) {
      if (t->tp == K_M && t->n_args) {
        vote_microdesc_hash_t *line =
          tor_malloc(sizeof(vote_microdesc_hash_t));
        line->next = vote_rs->microdesc;
        line->microdesc_hash_line = tor_strdup(t->args[0]);
        vote_rs->microdesc = line;
      }
      if (t->tp == K_ID) {
        tor_assert(t->n_args >= 2);
        if (!strcmp(t->args[0], "ed25519")) {
          vote_rs->has_ed25519_listing = 1;
          if (strcmp(t->args[1], "none") &&
              digest256_from_base64((char*)vote_rs->ed25519_id,
                                    t->args[1])<0) {
            log_warn(LD_DIR, "Bogus ed25519 key in networkstatus vote");
            goto err;
          }
        }
      }
      if (t->tp == K_PROTO) {
        tor_assert(t->n_args == 1);
        vote_rs->protocols = tor_strdup(t->args[0]);
      }
    } SMARTLIST_FOREACH_END(t);
  } else if (flav == FLAV_MICRODESC) {
    tok = find_opt_by_keyword(tokens, K_M);
    if (tok) {
      tor_assert(tok->n_args);
      if (digest256_from_base64(rs->descriptor_digest, tok->args[0])) {
        log_warn(LD_DIR, "Error decoding microdescriptor digest %s",
                 escaped(tok->args[0]));
        goto err;
      }
    } else {
      log_info(LD_BUG, "Found an entry in networkstatus with no "
               "microdescriptor digest. (Router %s ($%s) at %s:%d.)",
               rs->nickname, hex_str(rs->identity_digest, DIGEST_LEN),
               fmt_addr32(rs->addr), rs->or_port);
    }
  }

  if (!strcasecmp(rs->nickname, UNNAMED_ROUTER_NICKNAME))
    rs->is_named = 0;

  goto done;
 err:
  dump_desc(s_dup, "routerstatus entry");
  if (rs && !vote_rs)
    routerstatus_free(rs);
  rs = NULL;
 done:
  SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
  smartlist_clear(tokens);
  if (area) {
    DUMP_AREA(area, "routerstatus entry");
    memarea_clear(area);
  }
  *s = eos;

  return rs;
}

int
compare_vote_routerstatus_entries(const void **_a, const void **_b)
{
  const vote_routerstatus_t *a = *_a, *b = *_b;
  return fast_memcmp(a->status.identity_digest, b->status.identity_digest,
                     DIGEST_LEN);
}

/** Verify the bandwidth weights of a network status document */
int
networkstatus_verify_bw_weights(networkstatus_t *ns, int consensus_method)
{
  int64_t G=0, M=0, E=0, D=0, T=0;
  double Wgg, Wgm, Wgd, Wmg, Wmm, Wme, Wmd, Weg, Wem, Wee, Wed;
  double Gtotal=0, Mtotal=0, Etotal=0;
  const char *casename = NULL;
  int valid = 1;
  (void) consensus_method;

  const int64_t weight_scale = networkstatus_get_weight_scale_param(ns);
  tor_assert(weight_scale >= 1);
  Wgg = networkstatus_get_bw_weight(ns, "Wgg", -1);
  Wgm = networkstatus_get_bw_weight(ns, "Wgm", -1);
  Wgd = networkstatus_get_bw_weight(ns, "Wgd", -1);
  Wmg = networkstatus_get_bw_weight(ns, "Wmg", -1);
  Wmm = networkstatus_get_bw_weight(ns, "Wmm", -1);
  Wme = networkstatus_get_bw_weight(ns, "Wme", -1);
  Wmd = networkstatus_get_bw_weight(ns, "Wmd", -1);
  Weg = networkstatus_get_bw_weight(ns, "Weg", -1);
  Wem = networkstatus_get_bw_weight(ns, "Wem", -1);
  Wee = networkstatus_get_bw_weight(ns, "Wee", -1);
  Wed = networkstatus_get_bw_weight(ns, "Wed", -1);

  if (Wgg<0 || Wgm<0 || Wgd<0 || Wmg<0 || Wmm<0 || Wme<0 || Wmd<0 || Weg<0
          || Wem<0 || Wee<0 || Wed<0) {
    log_warn(LD_BUG, "No bandwidth weights produced in consensus!");
    return 0;
  }

  // First, sanity check basic summing properties that hold for all cases
  // We use > 1 as the check for these because they are computed as integers.
  // Sometimes there are rounding errors.
  if (fabs(Wmm - weight_scale) > 1) {
    log_warn(LD_BUG, "Wmm=%f != %"PRId64,
             Wmm, (weight_scale));
    valid = 0;
  }

  if (fabs(Wem - Wee) > 1) {
    log_warn(LD_BUG, "Wem=%f != Wee=%f", Wem, Wee);
    valid = 0;
  }

  if (fabs(Wgm - Wgg) > 1) {
    log_warn(LD_BUG, "Wgm=%f != Wgg=%f", Wgm, Wgg);
    valid = 0;
  }

  if (fabs(Weg - Wed) > 1) {
    log_warn(LD_BUG, "Wed=%f != Weg=%f", Wed, Weg);
    valid = 0;
  }

  if (fabs(Wgg + Wmg - weight_scale) > 0.001*weight_scale) {
    log_warn(LD_BUG, "Wgg=%f != %"PRId64" - Wmg=%f", Wgg,
             (weight_scale), Wmg);
    valid = 0;
  }

  if (fabs(Wee + Wme - weight_scale) > 0.001*weight_scale) {
    log_warn(LD_BUG, "Wee=%f != %"PRId64" - Wme=%f", Wee,
             (weight_scale), Wme);
    valid = 0;
  }

  if (fabs(Wgd + Wmd + Wed - weight_scale) > 0.001*weight_scale) {
    log_warn(LD_BUG, "Wgd=%f + Wmd=%f + Wed=%f != %"PRId64,
             Wgd, Wmd, Wed, (weight_scale));
    valid = 0;
  }

  Wgg /= weight_scale;
  Wgm /= weight_scale; (void) Wgm; // unused from here on.
  Wgd /= weight_scale;

  Wmg /= weight_scale;
  Wmm /= weight_scale;
  Wme /= weight_scale;
  Wmd /= weight_scale;

  Weg /= weight_scale; (void) Weg; // unused from here on.
  Wem /= weight_scale; (void) Wem; // unused from here on.
  Wee /= weight_scale;
  Wed /= weight_scale;

  // Then, gather G, M, E, D, T to determine case
  SMARTLIST_FOREACH_BEGIN(ns->routerstatus_list, routerstatus_t *, rs) {
    int is_exit = 0;
    /* Bug #2203: Don't count bad exits as exits for balancing */
    is_exit = rs->is_exit && !rs->is_bad_exit;
    if (rs->has_bandwidth) {
      T += rs->bandwidth_kb;
      if (is_exit && rs->is_possible_guard) {
        D += rs->bandwidth_kb;
        Gtotal += Wgd*rs->bandwidth_kb;
        Mtotal += Wmd*rs->bandwidth_kb;
        Etotal += Wed*rs->bandwidth_kb;
      } else if (is_exit) {
        E += rs->bandwidth_kb;
        Mtotal += Wme*rs->bandwidth_kb;
        Etotal += Wee*rs->bandwidth_kb;
      } else if (rs->is_possible_guard) {
        G += rs->bandwidth_kb;
        Gtotal += Wgg*rs->bandwidth_kb;
        Mtotal += Wmg*rs->bandwidth_kb;
      } else {
        M += rs->bandwidth_kb;
        Mtotal += Wmm*rs->bandwidth_kb;
      }
    } else {
      log_warn(LD_BUG, "Missing consensus bandwidth for router %s",
               routerstatus_describe(rs));
    }
  } SMARTLIST_FOREACH_END(rs);

  // Finally, check equality conditions depending upon case 1, 2 or 3
  // Full equality cases: 1, 3b
  // Partial equality cases: 2b (E=G), 3a (M=E)
  // Fully unknown: 2a
  if (3*E >= T && 3*G >= T) {
    // Case 1: Neither are scarce
    casename = "Case 1";
    if (fabs(Etotal-Mtotal) > 0.01*MAX(Etotal,Mtotal)) {
      log_warn(LD_DIR,
               "Bw Weight Failure for %s: Etotal %f != Mtotal %f. "
               "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
               " T=%"PRId64". "
               "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
               casename, Etotal, Mtotal,
               (G), (M), (E),
               (D), (T),
               Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
      valid = 0;
    }
    if (fabs(Etotal-Gtotal) > 0.01*MAX(Etotal,Gtotal)) {
      log_warn(LD_DIR,
               "Bw Weight Failure for %s: Etotal %f != Gtotal %f. "
               "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
               " T=%"PRId64". "
               "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
               casename, Etotal, Gtotal,
               (G), (M), (E),
               (D), (T),
               Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
      valid = 0;
    }
    if (fabs(Gtotal-Mtotal) > 0.01*MAX(Gtotal,Mtotal)) {
      log_warn(LD_DIR,
               "Bw Weight Failure for %s: Mtotal %f != Gtotal %f. "
               "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
               " T=%"PRId64". "
               "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
               casename, Mtotal, Gtotal,
               (G), (M), (E),
               (D), (T),
               Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
      valid = 0;
    }
  } else if (3*E < T && 3*G < T) {
    int64_t R = MIN(E, G);
    int64_t S = MAX(E, G);
    /*
     * Case 2: Both Guards and Exits are scarce
     * Balance D between E and G, depending upon
     * D capacity and scarcity. Devote no extra
     * bandwidth to middle nodes.
     */
    if (R+D < S) { // Subcase a
      double Rtotal, Stotal;
      if (E < G) {
        Rtotal = Etotal;
        Stotal = Gtotal;
      } else {
        Rtotal = Gtotal;
        Stotal = Etotal;
      }
      casename = "Case 2a";
      // Rtotal < Stotal
      if (Rtotal > Stotal) {
        log_warn(LD_DIR,
                   "Bw Weight Failure for %s: Rtotal %f > Stotal %f. "
                   "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                   " T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, Rtotal, Stotal,
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
        valid = 0;
      }
      // Rtotal < T/3
      if (3*Rtotal > T) {
        log_warn(LD_DIR,
                   "Bw Weight Failure for %s: 3*Rtotal %f > T "
                   "%"PRId64". G=%"PRId64" M=%"PRId64" E=%"PRId64
                   " D=%"PRId64" T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, Rtotal*3, (T),
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
        valid = 0;
      }
      // Stotal < T/3
      if (3*Stotal > T) {
        log_warn(LD_DIR,
                   "Bw Weight Failure for %s: 3*Stotal %f > T "
                   "%"PRId64". G=%"PRId64" M=%"PRId64" E=%"PRId64
                   " D=%"PRId64" T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, Stotal*3, (T),
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
        valid = 0;
      }
      // Mtotal > T/3
      if (3*Mtotal < T) {
        log_warn(LD_DIR,
                   "Bw Weight Failure for %s: 3*Mtotal %f < T "
                   "%"PRId64". "
                   "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                   " T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, Mtotal*3, (T),
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
        valid = 0;
      }
    } else { // Subcase b: R+D > S
      casename = "Case 2b";

      /* Check the rare-M redirect case. */
      if (D != 0 && 3*M < T) {
        casename = "Case 2b (balanced)";
        if (fabs(Etotal-Mtotal) > 0.01*MAX(Etotal,Mtotal)) {
          log_warn(LD_DIR,
                   "Bw Weight Failure for %s: Etotal %f != Mtotal %f. "
                   "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                   " T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, Etotal, Mtotal,
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
          valid = 0;
        }
        if (fabs(Etotal-Gtotal) > 0.01*MAX(Etotal,Gtotal)) {
          log_warn(LD_DIR,
                   "Bw Weight Failure for %s: Etotal %f != Gtotal %f. "
                   "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                   " T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, Etotal, Gtotal,
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
          valid = 0;
        }
        if (fabs(Gtotal-Mtotal) > 0.01*MAX(Gtotal,Mtotal)) {
          log_warn(LD_DIR,
                   "Bw Weight Failure for %s: Mtotal %f != Gtotal %f. "
                   "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                   " T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, Mtotal, Gtotal,
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
          valid = 0;
        }
      } else {
        if (fabs(Etotal-Gtotal) > 0.01*MAX(Etotal,Gtotal)) {
          log_warn(LD_DIR,
                   "Bw Weight Failure for %s: Etotal %f != Gtotal %f. "
                   "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                   " T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, Etotal, Gtotal,
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
          valid = 0;
        }
      }
    }
  } else { // if (E < T/3 || G < T/3) {
    int64_t S = MIN(E, G);
    int64_t NS = MAX(E, G);
    if (3*(S+D) < T) { // Subcase a:
      double Stotal;
      double NStotal;
      if (G < E) {
        casename = "Case 3a (G scarce)";
        Stotal = Gtotal;
        NStotal = Etotal;
      } else { // if (G >= E) {
        casename = "Case 3a (E scarce)";
        NStotal = Gtotal;
        Stotal = Etotal;
      }
      // Stotal < T/3
      if (3*Stotal > T) {
        log_warn(LD_DIR,
                   "Bw Weight Failure for %s: 3*Stotal %f > T "
                   "%"PRId64". G=%"PRId64" M=%"PRId64" E=%"PRId64
                   " D=%"PRId64" T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, Stotal*3, (T),
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
        valid = 0;
      }
      if (NS >= M) {
        if (fabs(NStotal-Mtotal) > 0.01*MAX(NStotal,Mtotal)) {
          log_warn(LD_DIR,
                   "Bw Weight Failure for %s: NStotal %f != Mtotal %f. "
                   "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                   " T=%"PRId64". "
                   "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                   casename, NStotal, Mtotal,
                   (G), (M), (E),
                   (D), (T),
                   Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
          valid = 0;
        }
      } else {
        // if NS < M, NStotal > T/3 because only one of G or E is scarce
        if (3*NStotal < T) {
          log_warn(LD_DIR,
                     "Bw Weight Failure for %s: 3*NStotal %f < T "
                     "%"PRId64". G=%"PRId64" M=%"PRId64
                     " E=%"PRId64" D=%"PRId64" T=%"PRId64". "
                     "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                     casename, NStotal*3, (T),
                     (G), (M), (E),
                     (D), (T),
                     Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
          valid = 0;
        }
      }
    } else { // Subcase b: S+D >= T/3
      casename = "Case 3b";
      if (fabs(Etotal-Mtotal) > 0.01*MAX(Etotal,Mtotal)) {
        log_warn(LD_DIR,
                 "Bw Weight Failure for %s: Etotal %f != Mtotal %f. "
                 "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                 " T=%"PRId64". "
                 "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                 casename, Etotal, Mtotal,
                 (G), (M), (E),
                 (D), (T),
                 Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
        valid = 0;
      }
      if (fabs(Etotal-Gtotal) > 0.01*MAX(Etotal,Gtotal)) {
        log_warn(LD_DIR,
                 "Bw Weight Failure for %s: Etotal %f != Gtotal %f. "
                 "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                 " T=%"PRId64". "
                 "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                 casename, Etotal, Gtotal,
                 (G), (M), (E),
                 (D), (T),
                 Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
        valid = 0;
      }
      if (fabs(Gtotal-Mtotal) > 0.01*MAX(Gtotal,Mtotal)) {
        log_warn(LD_DIR,
                 "Bw Weight Failure for %s: Mtotal %f != Gtotal %f. "
                 "G=%"PRId64" M=%"PRId64" E=%"PRId64" D=%"PRId64
                 " T=%"PRId64". "
                 "Wgg=%f Wgd=%f Wmg=%f Wme=%f Wmd=%f Wee=%f Wed=%f",
                 casename, Mtotal, Gtotal,
                 (G), (M), (E),
                 (D), (T),
                 Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed);
        valid = 0;
      }
    }
  }

  if (valid)
    log_notice(LD_DIR, "Bandwidth-weight %s is verified and valid.",
               casename);

  return valid;
}

/** Check if a shared random value of type <b>srv_type</b> is in
 *  <b>tokens</b>. If there is, parse it and set it to <b>srv_out</b>. Return
 *  -1 on failure, 0 on success. The resulting srv is allocated on the heap and
 *  it's the responsibility of the caller to free it. */
static int
extract_one_srv(smartlist_t *tokens, directory_keyword srv_type,
                sr_srv_t **srv_out)
{
  int ret = -1;
  directory_token_t *tok;
  sr_srv_t *srv = NULL;
  smartlist_t *chunks;

  tor_assert(tokens);

  chunks = smartlist_new();
  tok = find_opt_by_keyword(tokens, srv_type);
  if (!tok) {
    /* That's fine, no SRV is allowed. */
    ret = 0;
    goto end;
  }
  for (int i = 0; i < tok->n_args; i++) {
    smartlist_add(chunks, tok->args[i]);
  }
  srv = sr_parse_srv(chunks);
  if (srv == NULL) {
    log_warn(LD_DIR, "SR: Unparseable SRV %s", escaped(tok->object_body));
    goto end;
  }
  /* All is good. */
  *srv_out = srv;
  ret = 0;
 end:
  smartlist_free(chunks);
  return ret;
}

/** Extract any shared random values found in <b>tokens</b> and place them in
 *  the networkstatus <b>ns</b>. */
static void
extract_shared_random_srvs(networkstatus_t *ns, smartlist_t *tokens)
{
  const char *voter_identity;
  networkstatus_voter_info_t *voter;

  tor_assert(ns);
  tor_assert(tokens);
  /* Can be only one of them else code flow. */
  tor_assert(ns->type == NS_TYPE_VOTE || ns->type == NS_TYPE_CONSENSUS);

  if (ns->type == NS_TYPE_VOTE) {
    voter = smartlist_get(ns->voters, 0);
    tor_assert(voter);
    voter_identity = hex_str(voter->identity_digest,
                             sizeof(voter->identity_digest));
  } else {
    /* Consensus has multiple voters so no specific voter. */
    voter_identity = "consensus";
  }

  /* We extract both, and on error everything is stopped because it means
   * the vote is malformed for the shared random value(s). */
  if (extract_one_srv(tokens, K_PREVIOUS_SRV, &ns->sr_info.previous_srv) < 0) {
    log_warn(LD_DIR, "SR: Unable to parse previous SRV from %s",
             voter_identity);
    /* Maybe we have a chance with the current SRV so let's try it anyway. */
  }
  if (extract_one_srv(tokens, K_CURRENT_SRV, &ns->sr_info.current_srv) < 0) {
    log_warn(LD_DIR, "SR: Unable to parse current SRV from %s",
             voter_identity);
  }
}

/** Parse a v3 networkstatus vote, opinion, or consensus (depending on
 * ns_type), from <b>s</b>, and return the result.  Return NULL on failure. */
networkstatus_t *
networkstatus_parse_vote_from_string(const char *s, const char **eos_out,
                                     networkstatus_type_t ns_type)
{
  smartlist_t *tokens = smartlist_new();
  smartlist_t *rs_tokens = NULL, *footer_tokens = NULL;
  networkstatus_voter_info_t *voter = NULL;
  networkstatus_t *ns = NULL;
  common_digests_t ns_digests;
  uint8_t sha3_as_signed[DIGEST256_LEN];
  const char *cert, *end_of_header, *end_of_footer, *s_dup = s;
  directory_token_t *tok;
  struct in_addr in;
  int i, inorder, n_signatures = 0;
  memarea_t *area = NULL, *rs_area = NULL;
  consensus_flavor_t flav = FLAV_NS;
  char *last_kwd=NULL;

  tor_assert(s);

  if (eos_out)
    *eos_out = NULL;

  if (router_get_networkstatus_v3_hashes(s, &ns_digests) ||
      router_get_networkstatus_v3_sha3_as_signed(sha3_as_signed, s)<0) {
    log_warn(LD_DIR, "Unable to compute digest of network-status");
    goto err;
  }

  area = memarea_new();
  end_of_header = find_start_of_next_routerstatus(s);
  if (tokenize_string(area, s, end_of_header, tokens,
                      (ns_type == NS_TYPE_CONSENSUS) ?
                      networkstatus_consensus_token_table :
                      networkstatus_token_table, 0)) {
    log_warn(LD_DIR, "Error tokenizing network-status header");
    goto err;
  }

  ns = tor_malloc_zero(sizeof(networkstatus_t));
  memcpy(&ns->digests, &ns_digests, sizeof(ns_digests));
  memcpy(&ns->digest_sha3_as_signed, sha3_as_signed, sizeof(sha3_as_signed));

  tok = find_by_keyword(tokens, K_NETWORK_STATUS_VERSION);
  tor_assert(tok);
  if (tok->n_args > 1) {
    int flavor = networkstatus_parse_flavor_name(tok->args[1]);
    if (flavor < 0) {
      log_warn(LD_DIR, "Can't parse document with unknown flavor %s",
               escaped(tok->args[1]));
      goto err;
    }
    ns->flavor = flav = flavor;
  }
  if (flav != FLAV_NS && ns_type != NS_TYPE_CONSENSUS) {
    log_warn(LD_DIR, "Flavor found on non-consensus networkstatus.");
    goto err;
  }

  if (ns_type != NS_TYPE_CONSENSUS) {
    const char *end_of_cert = NULL;
    if (!(cert = strstr(s, "\ndir-key-certificate-version")))
      goto err;
    ++cert;
    ns->cert = authority_cert_parse_from_string(cert, &end_of_cert);
    if (!ns->cert || !end_of_cert || end_of_cert > end_of_header)
      goto err;
  }

  tok = find_by_keyword(tokens, K_VOTE_STATUS);
  tor_assert(tok->n_args);
  if (!strcmp(tok->args[0], "vote")) {
    ns->type = NS_TYPE_VOTE;
  } else if (!strcmp(tok->args[0], "consensus")) {
    ns->type = NS_TYPE_CONSENSUS;
  } else if (!strcmp(tok->args[0], "opinion")) {
    ns->type = NS_TYPE_OPINION;
  } else {
    log_warn(LD_DIR, "Unrecognized vote status %s in network-status",
             escaped(tok->args[0]));
    goto err;
  }
  if (ns_type != ns->type) {
    log_warn(LD_DIR, "Got the wrong kind of v3 networkstatus.");
    goto err;
  }

  if (ns->type == NS_TYPE_VOTE || ns->type == NS_TYPE_OPINION) {
    tok = find_by_keyword(tokens, K_PUBLISHED);
    if (parse_iso_time(tok->args[0], &ns->published))
      goto err;

    ns->supported_methods = smartlist_new();
    tok = find_opt_by_keyword(tokens, K_CONSENSUS_METHODS);
    if (tok) {
      for (i=0; i < tok->n_args; ++i)
        smartlist_add_strdup(ns->supported_methods, tok->args[i]);
    } else {
      smartlist_add_strdup(ns->supported_methods, "1");
    }
  } else {
    tok = find_opt_by_keyword(tokens, K_CONSENSUS_METHOD);
    if (tok) {
      int num_ok;
      ns->consensus_method = (int)tor_parse_long(tok->args[0], 10, 1, INT_MAX,
                                                 &num_ok, NULL);
      if (!num_ok)
        goto err;
    } else {
      ns->consensus_method = 1;
    }
  }

  if ((tok = find_opt_by_keyword(tokens, K_RECOMMENDED_CLIENT_PROTOCOLS)))
    ns->recommended_client_protocols = tor_strdup(tok->args[0]);
  if ((tok = find_opt_by_keyword(tokens, K_RECOMMENDED_RELAY_PROTOCOLS)))
    ns->recommended_relay_protocols = tor_strdup(tok->args[0]);
  if ((tok = find_opt_by_keyword(tokens, K_REQUIRED_CLIENT_PROTOCOLS)))
    ns->required_client_protocols = tor_strdup(tok->args[0]);
  if ((tok = find_opt_by_keyword(tokens, K_REQUIRED_RELAY_PROTOCOLS)))
    ns->required_relay_protocols = tor_strdup(tok->args[0]);

  tok = find_by_keyword(tokens, K_VALID_AFTER);
  if (parse_iso_time(tok->args[0], &ns->valid_after))
    goto err;

  tok = find_by_keyword(tokens, K_FRESH_UNTIL);
  if (parse_iso_time(tok->args[0], &ns->fresh_until))
    goto err;

  tok = find_by_keyword(tokens, K_VALID_UNTIL);
  if (parse_iso_time(tok->args[0], &ns->valid_until))
    goto err;

  tok = find_by_keyword(tokens, K_VOTING_DELAY);
  tor_assert(tok->n_args >= 2);
  {
    int ok;
    ns->vote_seconds =
      (int) tor_parse_long(tok->args[0], 10, 0, INT_MAX, &ok, NULL);
    if (!ok)
      goto err;
    ns->dist_seconds =
      (int) tor_parse_long(tok->args[1], 10, 0, INT_MAX, &ok, NULL);
    if (!ok)
      goto err;
  }
  if (ns->valid_after +
      (get_options()->TestingTorNetwork ?
       MIN_VOTE_INTERVAL_TESTING : MIN_VOTE_INTERVAL) > ns->fresh_until) {
    log_warn(LD_DIR, "Vote/consensus freshness interval is too short");
    goto err;
  }
  if (ns->valid_after +
      (get_options()->TestingTorNetwork ?
       MIN_VOTE_INTERVAL_TESTING : MIN_VOTE_INTERVAL)*2 > ns->valid_until) {
    log_warn(LD_DIR, "Vote/consensus liveness interval is too short");
    goto err;
  }
  if (ns->vote_seconds < MIN_VOTE_SECONDS) {
    log_warn(LD_DIR, "Vote seconds is too short");
    goto err;
  }
  if (ns->dist_seconds < MIN_DIST_SECONDS) {
    log_warn(LD_DIR, "Dist seconds is too short");
    goto err;
  }

  if ((tok = find_opt_by_keyword(tokens, K_CLIENT_VERSIONS))) {
    ns->client_versions = tor_strdup(tok->args[0]);
  }
  if ((tok = find_opt_by_keyword(tokens, K_SERVER_VERSIONS))) {
    ns->server_versions = tor_strdup(tok->args[0]);
  }

  {
    smartlist_t *package_lst = find_all_by_keyword(tokens, K_PACKAGE);
    ns->package_lines = smartlist_new();
    if (package_lst) {
      SMARTLIST_FOREACH(package_lst, directory_token_t *, t,
                    smartlist_add_strdup(ns->package_lines, t->args[0]));
    }
    smartlist_free(package_lst);
  }

  tok = find_by_keyword(tokens, K_KNOWN_FLAGS);
  ns->known_flags = smartlist_new();
  inorder = 1;
  for (i = 0; i < tok->n_args; ++i) {
    smartlist_add_strdup(ns->known_flags, tok->args[i]);
    if (i>0 && strcmp(tok->args[i-1], tok->args[i])>= 0) {
      log_warn(LD_DIR, "%s >= %s", tok->args[i-1], tok->args[i]);
      inorder = 0;
    }
  }
  if (!inorder) {
    log_warn(LD_DIR, "known-flags not in order");
    goto err;
  }
  if (ns->type != NS_TYPE_CONSENSUS &&
      smartlist_len(ns->known_flags) > MAX_KNOWN_FLAGS_IN_VOTE) {
    /* If we allowed more than 64 flags in votes, then parsing them would make
     * us invoke undefined behavior whenever we used 1<<flagnum to do a
     * bit-shift. This is only for votes and opinions: consensus users don't
     * care about flags they don't recognize, and so don't build a bitfield
     * for them. */
    log_warn(LD_DIR, "Too many known-flags in consensus vote or opinion");
    goto err;
  }

  tok = find_opt_by_keyword(tokens, K_PARAMS);
  if (tok) {
    int any_dups = 0;
    inorder = 1;
    ns->net_params = smartlist_new();
    for (i = 0; i < tok->n_args; ++i) {
      int ok=0;
      char *eq = strchr(tok->args[i], '=');
      size_t eq_pos;
      if (!eq) {
        log_warn(LD_DIR, "Bad element '%s' in params", escaped(tok->args[i]));
        goto err;
      }
      eq_pos = eq-tok->args[i];
      tor_parse_long(eq+1, 10, INT32_MIN, INT32_MAX, &ok, NULL);
      if (!ok) {
        log_warn(LD_DIR, "Bad element '%s' in params", escaped(tok->args[i]));
        goto err;
      }
      if (i > 0 && strcmp(tok->args[i-1], tok->args[i]) >= 0) {
        log_warn(LD_DIR, "%s >= %s", tok->args[i-1], tok->args[i]);
        inorder = 0;
      }
      if (last_kwd && eq_pos == strlen(last_kwd) &&
          fast_memeq(last_kwd, tok->args[i], eq_pos)) {
        log_warn(LD_DIR, "Duplicate value for %s parameter",
                 escaped(tok->args[i]));
        any_dups = 1;
      }
      tor_free(last_kwd);
      last_kwd = tor_strndup(tok->args[i], eq_pos);
      smartlist_add_strdup(ns->net_params, tok->args[i]);
    }
    if (!inorder) {
      log_warn(LD_DIR, "params not in order");
      goto err;
    }
    if (any_dups) {
      log_warn(LD_DIR, "Duplicate in parameters");
      goto err;
    }
  }

  ns->voters = smartlist_new();

  SMARTLIST_FOREACH_BEGIN(tokens, directory_token_t *, _tok) {
    tok = _tok;
    if (tok->tp == K_DIR_SOURCE) {
      tor_assert(tok->n_args >= 6);

      if (voter)
        smartlist_add(ns->voters, voter);
      voter = tor_malloc_zero(sizeof(networkstatus_voter_info_t));
      voter->sigs = smartlist_new();
      if (ns->type != NS_TYPE_CONSENSUS)
        memcpy(voter->vote_digest, ns_digests.d[DIGEST_SHA1], DIGEST_LEN);

      voter->nickname = tor_strdup(tok->args[0]);
      if (strlen(tok->args[1]) != HEX_DIGEST_LEN ||
          base16_decode(voter->identity_digest, sizeof(voter->identity_digest),
                        tok->args[1], HEX_DIGEST_LEN)
                        != sizeof(voter->identity_digest)) {
        log_warn(LD_DIR, "Error decoding identity digest %s in "
                 "network-status document.", escaped(tok->args[1]));
        goto err;
      }
      if (ns->type != NS_TYPE_CONSENSUS &&
          tor_memneq(ns->cert->cache_info.identity_digest,
                 voter->identity_digest, DIGEST_LEN)) {
        log_warn(LD_DIR,"Mismatch between identities in certificate and vote");
        goto err;
      }
      if (ns->type != NS_TYPE_CONSENSUS) {
        if (authority_cert_is_blacklisted(ns->cert)) {
          log_warn(LD_DIR, "Rejecting vote signature made with blacklisted "
                   "signing key %s",
                   hex_str(ns->cert->signing_key_digest, DIGEST_LEN));
          goto err;
        }
      }
      voter->address = tor_strdup(tok->args[2]);
      if (!tor_inet_aton(tok->args[3], &in)) {
        log_warn(LD_DIR, "Error decoding IP address %s in network-status.",
                 escaped(tok->args[3]));
        goto err;
      }
      voter->addr = ntohl(in.s_addr);
      int ok;
      voter->dir_port = (uint16_t)
        tor_parse_long(tok->args[4], 10, 0, 65535, &ok, NULL);
      if (!ok)
        goto err;
      voter->or_port = (uint16_t)
        tor_parse_long(tok->args[5], 10, 0, 65535, &ok, NULL);
      if (!ok)
        goto err;
    } else if (tok->tp == K_CONTACT) {
      if (!voter || voter->contact) {
        log_warn(LD_DIR, "contact element is out of place.");
        goto err;
      }
      voter->contact = tor_strdup(tok->args[0]);
    } else if (tok->tp == K_VOTE_DIGEST) {
      tor_assert(ns->type == NS_TYPE_CONSENSUS);
      tor_assert(tok->n_args >= 1);
      if (!voter || ! tor_digest_is_zero(voter->vote_digest)) {
        log_warn(LD_DIR, "vote-digest element is out of place.");
        goto err;
      }
      if (strlen(tok->args[0]) != HEX_DIGEST_LEN ||
        base16_decode(voter->vote_digest, sizeof(voter->vote_digest),
                      tok->args[0], HEX_DIGEST_LEN)
                      != sizeof(voter->vote_digest)) {
        log_warn(LD_DIR, "Error decoding vote digest %s in "
                 "network-status consensus.", escaped(tok->args[0]));
        goto err;
      }
    }
  } SMARTLIST_FOREACH_END(_tok);
  if (voter) {
    smartlist_add(ns->voters, voter);
    voter = NULL;
  }
  if (smartlist_len(ns->voters) == 0) {
    log_warn(LD_DIR, "Missing dir-source elements in a networkstatus.");
    goto err;
  } else if (ns->type != NS_TYPE_CONSENSUS && smartlist_len(ns->voters) != 1) {
    log_warn(LD_DIR, "Too many dir-source elements in a vote networkstatus.");
    goto err;
  }

  if (ns->type != NS_TYPE_CONSENSUS &&
      (tok = find_opt_by_keyword(tokens, K_LEGACY_DIR_KEY))) {
    int bad = 1;
    if (strlen(tok->args[0]) == HEX_DIGEST_LEN) {
      networkstatus_voter_info_t *voter_0 = smartlist_get(ns->voters, 0);
      if (base16_decode(voter_0->legacy_id_digest, DIGEST_LEN,
                        tok->args[0], HEX_DIGEST_LEN) != DIGEST_LEN)
        bad = 1;
      else
        bad = 0;
    }
    if (bad) {
      log_warn(LD_DIR, "Invalid legacy key digest %s on vote.",
               escaped(tok->args[0]));
    }
  }

  /* If this is a vote document, check if information about the shared
     randomness protocol is included, and extract it. */
  if (ns->type == NS_TYPE_VOTE) {
    dirvote_parse_sr_commits(ns, tokens);
  }
  /* For both a vote and consensus, extract the shared random values. */
  if (ns->type == NS_TYPE_VOTE || ns->type == NS_TYPE_CONSENSUS) {
    extract_shared_random_srvs(ns, tokens);
  }

  /* Parse routerstatus lines. */
  rs_tokens = smartlist_new();
  rs_area = memarea_new();
  s = end_of_header;
  ns->routerstatus_list = smartlist_new();

  while (!strcmpstart(s, "r ")) {
    if (ns->type != NS_TYPE_CONSENSUS) {
      vote_routerstatus_t *rs = tor_malloc_zero(sizeof(vote_routerstatus_t));
      if (routerstatus_parse_entry_from_string(rs_area, &s, rs_tokens, ns,
                                               rs, 0, 0)) {
        smartlist_add(ns->routerstatus_list, rs);
      } else {
        vote_routerstatus_free(rs);
      }
    } else {
      routerstatus_t *rs;
      if ((rs = routerstatus_parse_entry_from_string(rs_area, &s, rs_tokens,
                                                     NULL, NULL,
                                                     ns->consensus_method,
                                                     flav))) {
        /* Use exponential-backoff scheduling when downloading microdescs */
        smartlist_add(ns->routerstatus_list, rs);
      }
    }
  }
  for (i = 1; i < smartlist_len(ns->routerstatus_list); ++i) {
    routerstatus_t *rs1, *rs2;
    if (ns->type != NS_TYPE_CONSENSUS) {
      vote_routerstatus_t *a = smartlist_get(ns->routerstatus_list, i-1);
      vote_routerstatus_t *b = smartlist_get(ns->routerstatus_list, i);
      rs1 = &a->status; rs2 = &b->status;
    } else {
      rs1 = smartlist_get(ns->routerstatus_list, i-1);
      rs2 = smartlist_get(ns->routerstatus_list, i);
    }
    if (fast_memcmp(rs1->identity_digest, rs2->identity_digest, DIGEST_LEN)
        >= 0) {
      log_warn(LD_DIR, "Networkstatus entries not sorted by identity digest");
      goto err;
    }
  }
  if (ns_type != NS_TYPE_CONSENSUS) {
    digest256map_t *ed_id_map = digest256map_new();
    SMARTLIST_FOREACH_BEGIN(ns->routerstatus_list, vote_routerstatus_t *,
                            vrs) {
      if (! vrs->has_ed25519_listing ||
          tor_mem_is_zero((const char *)vrs->ed25519_id, DIGEST256_LEN))
        continue;
      if (digest256map_get(ed_id_map, vrs->ed25519_id) != NULL) {
        log_warn(LD_DIR, "Vote networkstatus ed25519 identities were not "
                 "unique");
        digest256map_free(ed_id_map, NULL);
        goto err;
      }
      digest256map_set(ed_id_map, vrs->ed25519_id, (void*)1);
    } SMARTLIST_FOREACH_END(vrs);
    digest256map_free(ed_id_map, NULL);
  }

  /* Parse footer; check signature. */
  footer_tokens = smartlist_new();
  if ((end_of_footer = strstr(s, "\nnetwork-status-version ")))
    ++end_of_footer;
  else
    end_of_footer = s + strlen(s);
  if (tokenize_string(area,s, end_of_footer, footer_tokens,
                      networkstatus_vote_footer_token_table, 0)) {
    log_warn(LD_DIR, "Error tokenizing network-status vote footer.");
    goto err;
  }

  {
    int found_sig = 0;
    SMARTLIST_FOREACH_BEGIN(footer_tokens, directory_token_t *, _tok) {
      tok = _tok;
      if (tok->tp == K_DIRECTORY_SIGNATURE)
        found_sig = 1;
      else if (found_sig) {
        log_warn(LD_DIR, "Extraneous token after first directory-signature");
        goto err;
      }
    } SMARTLIST_FOREACH_END(_tok);
  }

  if ((tok = find_opt_by_keyword(footer_tokens, K_DIRECTORY_FOOTER))) {
    if (tok != smartlist_get(footer_tokens, 0)) {
      log_warn(LD_DIR, "Misplaced directory-footer token");
      goto err;
    }
  }

  tok = find_opt_by_keyword(footer_tokens, K_BW_WEIGHTS);
  if (tok) {
    ns->weight_params = smartlist_new();
    for (i = 0; i < tok->n_args; ++i) {
      int ok=0;
      char *eq = strchr(tok->args[i], '=');
      if (!eq) {
        log_warn(LD_DIR, "Bad element '%s' in weight params",
                 escaped(tok->args[i]));
        goto err;
      }
      tor_parse_long(eq+1, 10, INT32_MIN, INT32_MAX, &ok, NULL);
      if (!ok) {
        log_warn(LD_DIR, "Bad element '%s' in params", escaped(tok->args[i]));
        goto err;
      }
      smartlist_add_strdup(ns->weight_params, tok->args[i]);
    }
  }

  SMARTLIST_FOREACH_BEGIN(footer_tokens, directory_token_t *, _tok) {
    char declared_identity[DIGEST_LEN];
    networkstatus_voter_info_t *v;
    document_signature_t *sig;
    const char *id_hexdigest = NULL;
    const char *sk_hexdigest = NULL;
    digest_algorithm_t alg = DIGEST_SHA1;
    tok = _tok;
    if (tok->tp != K_DIRECTORY_SIGNATURE)
      continue;
    tor_assert(tok->n_args >= 2);
    if (tok->n_args == 2) {
      id_hexdigest = tok->args[0];
      sk_hexdigest = tok->args[1];
    } else {
      const char *algname = tok->args[0];
      int a;
      id_hexdigest = tok->args[1];
      sk_hexdigest = tok->args[2];
      a = crypto_digest_algorithm_parse_name(algname);
      if (a<0) {
        log_warn(LD_DIR, "Unknown digest algorithm %s; skipping",
                 escaped(algname));
        continue;
      }
      alg = a;
    }

    if (!tok->object_type ||
        strcmp(tok->object_type, "SIGNATURE") ||
        tok->object_size < 128 || tok->object_size > 512) {
      log_warn(LD_DIR, "Bad object type or length on directory-signature");
      goto err;
    }

    if (strlen(id_hexdigest) != HEX_DIGEST_LEN ||
        base16_decode(declared_identity, sizeof(declared_identity),
                      id_hexdigest, HEX_DIGEST_LEN)
                      != sizeof(declared_identity)) {
      log_warn(LD_DIR, "Error decoding declared identity %s in "
               "network-status document.", escaped(id_hexdigest));
      goto err;
    }
    if (!(v = networkstatus_get_voter_by_id(ns, declared_identity))) {
      log_warn(LD_DIR, "ID on signature on network-status document does "
               "not match any declared directory source.");
      goto err;
    }
    sig = tor_malloc_zero(sizeof(document_signature_t));
    memcpy(sig->identity_digest, v->identity_digest, DIGEST_LEN);
    sig->alg = alg;
    if (strlen(sk_hexdigest) != HEX_DIGEST_LEN ||
        base16_decode(sig->signing_key_digest, sizeof(sig->signing_key_digest),
                      sk_hexdigest, HEX_DIGEST_LEN)
                      != sizeof(sig->signing_key_digest)) {
      log_warn(LD_DIR, "Error decoding declared signing key digest %s in "
               "network-status document.", escaped(sk_hexdigest));
      tor_free(sig);
      goto err;
    }

    if (ns->type != NS_TYPE_CONSENSUS) {
      if (tor_memneq(declared_identity, ns->cert->cache_info.identity_digest,
                 DIGEST_LEN)) {
        log_warn(LD_DIR, "Digest mismatch between declared and actual on "
                 "network-status vote.");
        tor_free(sig);
        goto err;
      }
    }

    if (networkstatus_get_voter_sig_by_alg(v, sig->alg)) {
      /* We already parsed a vote with this algorithm from this voter. Use the
         first one. */
      log_fn(LOG_PROTOCOL_WARN, LD_DIR, "We received a networkstatus "
             "that contains two signatures from the same voter with the same "
             "algorithm. Ignoring the second signature.");
      tor_free(sig);
      continue;
    }

    if (ns->type != NS_TYPE_CONSENSUS) {
      if (check_signature_token(ns_digests.d[DIGEST_SHA1], DIGEST_LEN,
                                tok, ns->cert->signing_key, 0,
                                "network-status document")) {
        tor_free(sig);
        goto err;
      }
      sig->good_signature = 1;
    } else {
      if (tok->object_size >= INT_MAX || tok->object_size >= SIZE_T_CEILING) {
        tor_free(sig);
        goto err;
      }
      sig->signature = tor_memdup(tok->object_body, tok->object_size);
      sig->signature_len = (int) tok->object_size;
    }
    smartlist_add(v->sigs, sig);

    ++n_signatures;
  } SMARTLIST_FOREACH_END(_tok);

  if (! n_signatures) {
    log_warn(LD_DIR, "No signatures on networkstatus document.");
    goto err;
  } else if (ns->type == NS_TYPE_VOTE && n_signatures != 1) {
    log_warn(LD_DIR, "Received more than one signature on a "
             "network-status vote.");
    goto err;
  }

  if (eos_out)
    *eos_out = end_of_footer;

  goto done;
 err:
  dump_desc(s_dup, "v3 networkstatus");
  networkstatus_vote_free(ns);
  ns = NULL;
 done:
  if (tokens) {
    SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
    smartlist_free(tokens);
  }
  if (voter) {
    if (voter->sigs) {
      SMARTLIST_FOREACH(voter->sigs, document_signature_t *, sig,
                        document_signature_free(sig));
      smartlist_free(voter->sigs);
    }
    tor_free(voter->nickname);
    tor_free(voter->address);
    tor_free(voter->contact);
    tor_free(voter);
  }
  if (rs_tokens) {
    SMARTLIST_FOREACH(rs_tokens, directory_token_t *, t, token_clear(t));
    smartlist_free(rs_tokens);
  }
  if (footer_tokens) {
    SMARTLIST_FOREACH(footer_tokens, directory_token_t *, t, token_clear(t));
    smartlist_free(footer_tokens);
  }
  if (area) {
    DUMP_AREA(area, "v3 networkstatus");
    memarea_drop_all(area);
  }
  if (rs_area)
    memarea_drop_all(rs_area);
  tor_free(last_kwd);

  return ns;
}

/** Return the common_digests_t that holds the digests of the
 * <b>flavor_name</b>-flavored networkstatus according to the detached
 * signatures document <b>sigs</b>, allocating a new common_digests_t as
 * needed. */
static common_digests_t *
detached_get_digests(ns_detached_signatures_t *sigs, const char *flavor_name)
{
  common_digests_t *d = strmap_get(sigs->digests, flavor_name);
  if (!d) {
    d = tor_malloc_zero(sizeof(common_digests_t));
    strmap_set(sigs->digests, flavor_name, d);
  }
  return d;
}

/** Return the list of signatures of the <b>flavor_name</b>-flavored
 * networkstatus according to the detached signatures document <b>sigs</b>,
 * allocating a new common_digests_t as needed. */
static smartlist_t *
detached_get_signatures(ns_detached_signatures_t *sigs,
                        const char *flavor_name)
{
  smartlist_t *sl = strmap_get(sigs->signatures, flavor_name);
  if (!sl) {
    sl = smartlist_new();
    strmap_set(sigs->signatures, flavor_name, sl);
  }
  return sl;
}

/** Parse a detached v3 networkstatus signature document between <b>s</b> and
 * <b>eos</b> and return the result.  Return -1 on failure. */
ns_detached_signatures_t *
networkstatus_parse_detached_signatures(const char *s, const char *eos)
{
  /* XXXX there is too much duplicate shared between this function and
   * networkstatus_parse_vote_from_string(). */
  directory_token_t *tok;
  memarea_t *area = NULL;
  common_digests_t *digests;

  smartlist_t *tokens = smartlist_new();
  ns_detached_signatures_t *sigs =
    tor_malloc_zero(sizeof(ns_detached_signatures_t));
  sigs->digests = strmap_new();
  sigs->signatures = strmap_new();

  if (!eos)
    eos = s + strlen(s);

  area = memarea_new();
  if (tokenize_string(area,s, eos, tokens,
                      networkstatus_detached_signature_token_table, 0)) {
    log_warn(LD_DIR, "Error tokenizing detached networkstatus signatures");
    goto err;
  }

  /* Grab all the digest-like tokens. */
  SMARTLIST_FOREACH_BEGIN(tokens, directory_token_t *, _tok) {
    const char *algname;
    digest_algorithm_t alg;
    const char *flavor;
    const char *hexdigest;
    size_t expected_length, digest_length;

    tok = _tok;

    if (tok->tp == K_CONSENSUS_DIGEST) {
      algname = "sha1";
      alg = DIGEST_SHA1;
      flavor = "ns";
      hexdigest = tok->args[0];
    } else if (tok->tp == K_ADDITIONAL_DIGEST) {
      int a = crypto_digest_algorithm_parse_name(tok->args[1]);
      if (a<0) {
        log_warn(LD_DIR, "Unrecognized algorithm name %s", tok->args[0]);
        continue;
      }
      alg = (digest_algorithm_t) a;
      flavor = tok->args[0];
      algname = tok->args[1];
      hexdigest = tok->args[2];
    } else {
      continue;
    }

    digest_length = crypto_digest_algorithm_get_length(alg);
    expected_length = digest_length * 2; /* hex encoding */

    if (strlen(hexdigest) != expected_length) {
      log_warn(LD_DIR, "Wrong length on consensus-digest in detached "
               "networkstatus signatures");
      goto err;
    }
    digests = detached_get_digests(sigs, flavor);
    tor_assert(digests);
    if (!tor_mem_is_zero(digests->d[alg], digest_length)) {
      log_warn(LD_DIR, "Multiple digests for %s with %s on detached "
               "signatures document", flavor, algname);
      continue;
    }
    if (base16_decode(digests->d[alg], digest_length,
                      hexdigest, strlen(hexdigest)) != (int) digest_length) {
      log_warn(LD_DIR, "Bad encoding on consensus-digest in detached "
               "networkstatus signatures");
      goto err;
    }
  } SMARTLIST_FOREACH_END(_tok);

  tok = find_by_keyword(tokens, K_VALID_AFTER);
  if (parse_iso_time(tok->args[0], &sigs->valid_after)) {
    log_warn(LD_DIR, "Bad valid-after in detached networkstatus signatures");
    goto err;
  }

  tok = find_by_keyword(tokens, K_FRESH_UNTIL);
  if (parse_iso_time(tok->args[0], &sigs->fresh_until)) {
    log_warn(LD_DIR, "Bad fresh-until in detached networkstatus signatures");
    goto err;
  }

  tok = find_by_keyword(tokens, K_VALID_UNTIL);
  if (parse_iso_time(tok->args[0], &sigs->valid_until)) {
    log_warn(LD_DIR, "Bad valid-until in detached networkstatus signatures");
    goto err;
  }

  SMARTLIST_FOREACH_BEGIN(tokens, directory_token_t *, _tok) {
    const char *id_hexdigest;
    const char *sk_hexdigest;
    const char *algname;
    const char *flavor;
    digest_algorithm_t alg;

    char id_digest[DIGEST_LEN];
    char sk_digest[DIGEST_LEN];
    smartlist_t *siglist;
    document_signature_t *sig;
    int is_duplicate;

    tok = _tok;
    if (tok->tp == K_DIRECTORY_SIGNATURE) {
      tor_assert(tok->n_args >= 2);
      flavor = "ns";
      algname = "sha1";
      id_hexdigest = tok->args[0];
      sk_hexdigest = tok->args[1];
    } else if (tok->tp == K_ADDITIONAL_SIGNATURE) {
      tor_assert(tok->n_args >= 4);
      flavor = tok->args[0];
      algname = tok->args[1];
      id_hexdigest = tok->args[2];
      sk_hexdigest = tok->args[3];
    } else {
      continue;
    }

    {
      int a = crypto_digest_algorithm_parse_name(algname);
      if (a<0) {
        log_warn(LD_DIR, "Unrecognized algorithm name %s", algname);
        continue;
      }
      alg = (digest_algorithm_t) a;
    }

    if (!tok->object_type ||
        strcmp(tok->object_type, "SIGNATURE") ||
        tok->object_size < 128 || tok->object_size > 512) {
      log_warn(LD_DIR, "Bad object type or length on directory-signature");
      goto err;
    }

    if (strlen(id_hexdigest) != HEX_DIGEST_LEN ||
        base16_decode(id_digest, sizeof(id_digest),
                      id_hexdigest, HEX_DIGEST_LEN) != sizeof(id_digest)) {
      log_warn(LD_DIR, "Error decoding declared identity %s in "
               "network-status vote.", escaped(id_hexdigest));
      goto err;
    }
    if (strlen(sk_hexdigest) != HEX_DIGEST_LEN ||
        base16_decode(sk_digest, sizeof(sk_digest),
                      sk_hexdigest, HEX_DIGEST_LEN) != sizeof(sk_digest)) {
      log_warn(LD_DIR, "Error decoding declared signing key digest %s in "
               "network-status vote.", escaped(sk_hexdigest));
      goto err;
    }

    siglist = detached_get_signatures(sigs, flavor);
    is_duplicate = 0;
    SMARTLIST_FOREACH(siglist, document_signature_t *, dsig, {
      if (dsig->alg == alg &&
          tor_memeq(id_digest, dsig->identity_digest, DIGEST_LEN) &&
          tor_memeq(sk_digest, dsig->signing_key_digest, DIGEST_LEN)) {
        is_duplicate = 1;
      }
    });
    if (is_duplicate) {
      log_warn(LD_DIR, "Two signatures with identical keys and algorithm "
               "found.");
      continue;
    }

    sig = tor_malloc_zero(sizeof(document_signature_t));
    sig->alg = alg;
    memcpy(sig->identity_digest, id_digest, DIGEST_LEN);
    memcpy(sig->signing_key_digest, sk_digest, DIGEST_LEN);
    if (tok->object_size >= INT_MAX || tok->object_size >= SIZE_T_CEILING) {
      tor_free(sig);
      goto err;
    }
    sig->signature = tor_memdup(tok->object_body, tok->object_size);
    sig->signature_len = (int) tok->object_size;

    smartlist_add(siglist, sig);
  } SMARTLIST_FOREACH_END(_tok);

  goto done;
 err:
  ns_detached_signatures_free(sigs);
  sigs = NULL;
 done:
  SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
  smartlist_free(tokens);
  if (area) {
    DUMP_AREA(area, "detached signatures");
    memarea_drop_all(area);
  }
  return sigs;
}

/** Parse the addr policy in the string <b>s</b> and return it.  If
 * assume_action is nonnegative, then insert its action (ADDR_POLICY_ACCEPT or
 * ADDR_POLICY_REJECT) for items that specify no action.
 *
 * Returns NULL on policy errors.
 *
 * Set *<b>malformed_list</b> to true if the entire policy list should be
 * discarded. Otherwise, set it to false, and only this item should be ignored
 * on error - the rest of the policy list can continue to be processed and
 * used.
 *
 * The addr_policy_t returned by this function can have its address set to
 * AF_UNSPEC for '*'.  Use policy_expand_unspec() to turn this into a pair
 * of AF_INET and AF_INET6 items.
 */
MOCK_IMPL(addr_policy_t *,
router_parse_addr_policy_item_from_string,(const char *s, int assume_action,
                                           int *malformed_list))
{
  directory_token_t *tok = NULL;
  const char *cp, *eos;
  /* Longest possible policy is
   * "accept6 [ffff:ffff:..255]/128:10000-65535",
   * which contains a max-length IPv6 address, plus 26 characters.
   * But note that there can be an arbitrary amount of space between the
   * accept and the address:mask/port element.
   * We don't need to multiply TOR_ADDR_BUF_LEN by 2, as there is only one
   * IPv6 address. But making the buffer shorter might cause valid long lines,
   * which parsed in previous versions, to fail to parse in new versions.
   * (These lines would have to have excessive amounts of whitespace.) */
  char line[TOR_ADDR_BUF_LEN*2 + 32];
  addr_policy_t *r;
  memarea_t *area = NULL;

  tor_assert(malformed_list);
  *malformed_list = 0;

  s = eat_whitespace(s);
  /* We can only do assume_action on []-quoted IPv6, as "a" (accept)
   * and ":" (port separator) are ambiguous */
  if ((*s == '*' || *s == '[' || TOR_ISDIGIT(*s)) && assume_action >= 0) {
    if (tor_snprintf(line, sizeof(line), "%s %s",
               assume_action == ADDR_POLICY_ACCEPT?"accept":"reject", s)<0) {
      log_warn(LD_DIR, "Policy %s is too long.", escaped(s));
      return NULL;
    }
    cp = line;
    tor_strlower(line);
  } else { /* assume an already well-formed address policy line */
    cp = s;
  }

  eos = cp + strlen(cp);
  area = memarea_new();
  tok = get_next_token(area, &cp, eos, routerdesc_token_table);
  if (tok->tp == ERR_) {
    log_warn(LD_DIR, "Error reading address policy: %s", tok->error);
    goto err;
  }
  if (tok->tp != K_ACCEPT && tok->tp != K_ACCEPT6 &&
      tok->tp != K_REJECT && tok->tp != K_REJECT6) {
    log_warn(LD_DIR, "Expected 'accept' or 'reject'.");
    goto err;
  }

  /* Use the extended interpretation of accept/reject *,
   * expanding it into an IPv4 wildcard and an IPv6 wildcard.
   * Also permit *4 and *6 for IPv4 and IPv6 only wildcards. */
  r = router_parse_addr_policy(tok, TAPMP_EXTENDED_STAR);
  if (!r) {
    goto err;
  }

  /* Ensure that accept6/reject6 fields are followed by IPv6 addresses.
   * AF_UNSPEC addresses are only permitted on the accept/reject field type.
   * Unlike descriptors, torrcs exit policy accept/reject can be followed by
   * either an IPv4 or IPv6 address. */
  if ((tok->tp == K_ACCEPT6 || tok->tp == K_REJECT6) &&
       tor_addr_family(&r->addr) != AF_INET6) {
    /* This is a non-fatal error, just ignore this one entry. */
    *malformed_list = 0;
    log_warn(LD_DIR, "IPv4 address '%s' with accept6/reject6 field type in "
             "exit policy. Ignoring, but continuing to parse rules. (Use "
             "accept/reject with IPv4 addresses.)",
             tok->n_args == 1 ? tok->args[0] : "");
    addr_policy_free(r);
    r = NULL;
    goto done;
  }

  goto done;
 err:
  *malformed_list = 1;
  r = NULL;
 done:
  token_clear(tok);
  if (area) {
    DUMP_AREA(area, "policy item");
    memarea_drop_all(area);
  }
  return r;
}

/** Add an exit policy stored in the token <b>tok</b> to the router info in
 * <b>router</b>.  Return 0 on success, -1 on failure. */
static int
router_add_exit_policy(routerinfo_t *router, directory_token_t *tok)
{
  addr_policy_t *newe;
  /* Use the standard interpretation of accept/reject *, an IPv4 wildcard. */
  newe = router_parse_addr_policy(tok, 0);
  if (!newe)
    return -1;
  if (! router->exit_policy)
    router->exit_policy = smartlist_new();

  /* Ensure that in descriptors, accept/reject fields are followed by
   * IPv4 addresses, and accept6/reject6 fields are followed by
   * IPv6 addresses. Unlike torrcs, descriptor exit policies do not permit
   * accept/reject followed by IPv6. */
  if (((tok->tp == K_ACCEPT6 || tok->tp == K_REJECT6) &&
       tor_addr_family(&newe->addr) == AF_INET)
      ||
      ((tok->tp == K_ACCEPT || tok->tp == K_REJECT) &&
       tor_addr_family(&newe->addr) == AF_INET6)) {
    /* There's nothing the user can do about other relays' descriptors,
     * so we don't provide usage advice here. */
    log_warn(LD_DIR, "Mismatch between field type and address type in exit "
             "policy '%s'. Discarding entire router descriptor.",
             tok->n_args == 1 ? tok->args[0] : "");
    addr_policy_free(newe);
    return -1;
  }

  smartlist_add(router->exit_policy, newe);

  return 0;
}

/** Given a K_ACCEPT[6] or K_REJECT[6] token and a router, create and return
 * a new exit_policy_t corresponding to the token. If TAPMP_EXTENDED_STAR
 * is set in fmt_flags, K_ACCEPT6 and K_REJECT6 tokens followed by *
 * expand to IPv6-only policies, otherwise they expand to IPv4 and IPv6
 * policies */
static addr_policy_t *
router_parse_addr_policy(directory_token_t *tok, unsigned fmt_flags)
{
  addr_policy_t newe;
  char *arg;

  tor_assert(tok->tp == K_REJECT || tok->tp == K_REJECT6 ||
             tok->tp == K_ACCEPT || tok->tp == K_ACCEPT6);

  if (tok->n_args != 1)
    return NULL;
  arg = tok->args[0];

  if (!strcmpstart(arg,"private"))
    return router_parse_addr_policy_private(tok);

  memset(&newe, 0, sizeof(newe));

  if (tok->tp == K_REJECT || tok->tp == K_REJECT6)
    newe.policy_type = ADDR_POLICY_REJECT;
  else
    newe.policy_type = ADDR_POLICY_ACCEPT;

  /* accept6/reject6 * produces an IPv6 wildcard address only.
   * (accept/reject * produces rules for IPv4 and IPv6 wildcard addresses.) */
  if ((fmt_flags & TAPMP_EXTENDED_STAR)
      && (tok->tp == K_ACCEPT6 || tok->tp == K_REJECT6)) {
    fmt_flags |= TAPMP_STAR_IPV6_ONLY;
  }

  if (tor_addr_parse_mask_ports(arg, fmt_flags, &newe.addr, &newe.maskbits,
                                &newe.prt_min, &newe.prt_max) < 0) {
    log_warn(LD_DIR,"Couldn't parse line %s. Dropping", escaped(arg));
    return NULL;
  }

  return addr_policy_get_canonical_entry(&newe);
}

/** Parse an exit policy line of the format "accept[6]/reject[6] private:...".
 * This didn't exist until Tor 0.1.1.15, so nobody should generate it in
 * router descriptors until earlier versions are obsolete.
 *
 * accept/reject and accept6/reject6 private all produce rules for both
 * IPv4 and IPv6 addresses.
 */
static addr_policy_t *
router_parse_addr_policy_private(directory_token_t *tok)
{
  const char *arg;
  uint16_t port_min, port_max;
  addr_policy_t result;

  arg = tok->args[0];
  if (strcmpstart(arg, "private"))
    return NULL;

  arg += strlen("private");
  arg = (char*) eat_whitespace(arg);
  if (!arg || *arg != ':')
    return NULL;

  if (parse_port_range(arg+1, &port_min, &port_max)<0)
    return NULL;

  memset(&result, 0, sizeof(result));
  if (tok->tp == K_REJECT || tok->tp == K_REJECT6)
    result.policy_type = ADDR_POLICY_REJECT;
  else
    result.policy_type = ADDR_POLICY_ACCEPT;
  result.is_private = 1;
  result.prt_min = port_min;
  result.prt_max = port_max;

  if (tok->tp == K_ACCEPT6 || tok->tp == K_REJECT6) {
    log_warn(LD_GENERAL,
             "'%s' expands into rules which apply to all private IPv4 and "
             "IPv6 addresses. (Use accept/reject private:* for IPv4 and "
             "IPv6.)", tok->n_args == 1 ? tok->args[0] : "");
  }

  return addr_policy_get_canonical_entry(&result);
}

/** Return a newly allocated smartlist of all accept or reject tokens in
 * <b>s</b>.
 */
static smartlist_t *
find_all_exitpolicy(smartlist_t *s)
{
  smartlist_t *out = smartlist_new();
  SMARTLIST_FOREACH(s, directory_token_t *, t,
      if (t->tp == K_ACCEPT || t->tp == K_ACCEPT6 ||
          t->tp == K_REJECT || t->tp == K_REJECT6)
        smartlist_add(out,t));
  return out;
}

/** Called on startup; right now we just handle scanning the unparseable
 * descriptor dumps, but hang anything else we might need to do in the
 * future here as well.
 */
void
routerparse_init(void)
{
  /*
   * Check both if the sandbox is active and whether it's configured; no
   * point in loading all that if we won't be able to use it after the
   * sandbox becomes active.
   */
  if (!(sandbox_is_active() || get_options()->Sandbox)) {
    dump_desc_init();
  }
}

/** Clean up all data structures used by routerparse.c at exit */
void
routerparse_free_all(void)
{
  dump_desc_fifo_cleanup();
}