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- /* 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 microdesc_parse.c
- * \brief Code to parse and validate microdescriptors.
- **/
- #include "core/or/or.h"
- #include "app/config/config.h"
- #include "core/or/policies.h"
- #include "feature/dirparse/microdesc_parse.h"
- #include "feature/dirparse/parsecommon.h"
- #include "feature/dirparse/routerparse.h"
- #include "feature/nodelist/microdesc.h"
- #include "feature/nodelist/nickname.h"
- #include "feature/relay/router.h"
- #include "lib/crypt_ops/crypto_curve25519.h"
- #include "lib/crypt_ops/crypto_ed25519.h"
- #include "lib/crypt_ops/crypto_format.h"
- #include "lib/memarea/memarea.h"
- #include "feature/nodelist/microdesc_st.h"
- /** List of tokens recognized in microdescriptors */
- static token_rule_t microdesc_token_table[] = {
- T1_START("onion-key", K_ONION_KEY, NO_ARGS, NEED_KEY_1024),
- T01("ntor-onion-key", K_ONION_KEY_NTOR, GE(1), NO_OBJ ),
- T0N("id", K_ID, GE(2), NO_OBJ ),
- T0N("a", K_A, GE(1), NO_OBJ ),
- T01("family", K_FAMILY, ARGS, NO_OBJ ),
- T01("p", K_P, CONCAT_ARGS, NO_OBJ ),
- T01("p6", K_P6, CONCAT_ARGS, NO_OBJ ),
- A01("@last-listed", A_LAST_LISTED, CONCAT_ARGS, NO_OBJ ),
- END_OF_TABLE
- };
- /** Assuming that s starts with a microdesc, return the start of the
- * *NEXT* one. Return NULL on "not found." */
- static const char *
- find_start_of_next_microdesc(const char *s, const char *eos)
- {
- int started_with_annotations;
- s = eat_whitespace_eos(s, eos);
- if (!s)
- return NULL;
- #define CHECK_LENGTH() STMT_BEGIN \
- if (eos - s < 32) \
- return NULL; \
- STMT_END
- #define NEXT_LINE() STMT_BEGIN \
- s = memchr(s, '\n', eos-s); \
- if (!s || eos - s <= 1) \
- return NULL; \
- s++; \
- STMT_END
- CHECK_LENGTH();
- started_with_annotations = (*s == '@');
- if (started_with_annotations) {
- /* Start by advancing to the first non-annotation line. */
- while (*s == '@')
- NEXT_LINE();
- }
- CHECK_LENGTH();
- /* Now we should be pointed at an onion-key line. If we are, then skip
- * it. */
- if (!strcmpstart(s, "onion-key"))
- NEXT_LINE();
- /* Okay, now we're pointed at the first line of the microdescriptor which is
- not an annotation or onion-key. The next line that _is_ an annotation or
- onion-key is the start of the next microdescriptor. */
- while (eos - s > 32) {
- if (*s == '@' || !strcmpstart(s, "onion-key"))
- return s;
- NEXT_LINE();
- }
- return NULL;
- #undef CHECK_LENGTH
- #undef NEXT_LINE
- }
- /** Parse as many microdescriptors as are found from the string starting at
- * <b>s</b> and ending at <b>eos</b>. If allow_annotations is set, read any
- * annotations we recognize and ignore ones we don't.
- *
- * If <b>saved_location</b> isn't SAVED_IN_CACHE, make a local copy of each
- * descriptor in the body field of each microdesc_t.
- *
- * Return all newly parsed microdescriptors in a newly allocated
- * smartlist_t. If <b>invalid_disgests_out</b> is provided, add a SHA256
- * microdesc digest to it for every microdesc that we found to be badly
- * formed. (This may cause duplicates) */
- smartlist_t *
- microdescs_parse_from_string(const char *s, const char *eos,
- int allow_annotations,
- saved_location_t where,
- smartlist_t *invalid_digests_out)
- {
- smartlist_t *tokens;
- smartlist_t *result;
- microdesc_t *md = NULL;
- memarea_t *area;
- const char *start = s;
- const char *start_of_next_microdesc;
- int flags = allow_annotations ? TS_ANNOTATIONS_OK : 0;
- const int copy_body = (where != SAVED_IN_CACHE);
- directory_token_t *tok;
- if (!eos)
- eos = s + strlen(s);
- s = eat_whitespace_eos(s, eos);
- area = memarea_new();
- result = smartlist_new();
- tokens = smartlist_new();
- while (s < eos) {
- int okay = 0;
- start_of_next_microdesc = find_start_of_next_microdesc(s, eos);
- if (!start_of_next_microdesc)
- start_of_next_microdesc = eos;
- md = tor_malloc_zero(sizeof(microdesc_t));
- {
- const char *cp = tor_memstr(s, start_of_next_microdesc-s,
- "onion-key");
- const int no_onion_key = (cp == NULL);
- if (no_onion_key) {
- cp = s; /* So that we have *some* junk to put in the body */
- }
- md->bodylen = start_of_next_microdesc - cp;
- md->saved_location = where;
- if (copy_body)
- md->body = tor_memdup_nulterm(cp, md->bodylen);
- else
- md->body = (char*)cp;
- md->off = cp - start;
- crypto_digest256(md->digest, md->body, md->bodylen, DIGEST_SHA256);
- if (no_onion_key) {
- log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Malformed or truncated descriptor");
- goto next;
- }
- }
- if (tokenize_string(area, s, start_of_next_microdesc, tokens,
- microdesc_token_table, flags)) {
- log_warn(LD_DIR, "Unparseable microdescriptor");
- goto next;
- }
- if ((tok = find_opt_by_keyword(tokens, A_LAST_LISTED))) {
- if (parse_iso_time(tok->args[0], &md->last_listed)) {
- log_warn(LD_DIR, "Bad last-listed time in microdescriptor");
- goto next;
- }
- }
- 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 next;
- }
- router_set_rsa_onion_pkey(tok->key, &md->onion_pkey,
- &md->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 microdesc");
- goto next;
- }
- md->onion_curve25519_pkey =
- tor_memdup(&k, sizeof(curve25519_public_key_t));
- }
- smartlist_t *id_lines = find_all_by_keyword(tokens, K_ID);
- if (id_lines) {
- SMARTLIST_FOREACH_BEGIN(id_lines, directory_token_t *, t) {
- tor_assert(t->n_args >= 2);
- if (!strcmp(t->args[0], "ed25519")) {
- if (md->ed25519_identity_pkey) {
- log_warn(LD_DIR, "Extra ed25519 key in microdesc");
- smartlist_free(id_lines);
- goto next;
- }
- ed25519_public_key_t k;
- if (ed25519_public_from_base64(&k, t->args[1])<0) {
- log_warn(LD_DIR, "Bogus ed25519 key in microdesc");
- smartlist_free(id_lines);
- goto next;
- }
- md->ed25519_identity_pkey = tor_memdup(&k, sizeof(k));
- }
- } SMARTLIST_FOREACH_END(t);
- smartlist_free(id_lines);
- }
- {
- smartlist_t *a_lines = find_all_by_keyword(tokens, K_A);
- if (a_lines) {
- find_single_ipv6_orport(a_lines, &md->ipv6_addr, &md->ipv6_orport);
- smartlist_free(a_lines);
- }
- }
- if ((tok = find_opt_by_keyword(tokens, K_FAMILY))) {
- int i;
- md->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 next;
- }
- smartlist_add_strdup(md->family, tok->args[i]);
- }
- }
- if ((tok = find_opt_by_keyword(tokens, K_P))) {
- md->exit_policy = parse_short_policy(tok->args[0]);
- }
- if ((tok = find_opt_by_keyword(tokens, K_P6))) {
- md->ipv6_exit_policy = parse_short_policy(tok->args[0]);
- }
- smartlist_add(result, md);
- okay = 1;
- md = NULL;
- next:
- if (! okay && invalid_digests_out) {
- smartlist_add(invalid_digests_out,
- tor_memdup(md->digest, DIGEST256_LEN));
- }
- microdesc_free(md);
- md = NULL;
- SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
- memarea_clear(area);
- smartlist_clear(tokens);
- s = start_of_next_microdesc;
- }
- SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
- memarea_drop_all(area);
- smartlist_free(tokens);
- return result;
- }
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