diff options
Diffstat (limited to 'src/feature/dirparse/microdesc_parse.c')
-rw-r--r-- | src/feature/dirparse/microdesc_parse.c | 320 |
1 files changed, 203 insertions, 117 deletions
diff --git a/src/feature/dirparse/microdesc_parse.c b/src/feature/dirparse/microdesc_parse.c index 5a75af3994..9231080aaa 100644 --- a/src/feature/dirparse/microdesc_parse.c +++ b/src/feature/dirparse/microdesc_parse.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -18,6 +18,7 @@ #include "feature/dirparse/routerparse.h" #include "feature/nodelist/microdesc.h" #include "feature/nodelist/nickname.h" +#include "feature/nodelist/nodefamily.h" #include "feature/relay/router.h" #include "lib/crypt_ops/crypto_curve25519.h" #include "lib/crypt_ops/crypto_ed25519.h" @@ -27,17 +28,19 @@ #include "feature/nodelist/microdesc_st.h" /** List of tokens recognized in microdescriptors */ +// clang-format off 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("family", K_FAMILY, CONCAT_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 }; +// clang-format on /** Assuming that s starts with a microdesc, return the start of the * *NEXT* one. Return NULL on "not found." */ @@ -91,6 +94,190 @@ find_start_of_next_microdesc(const char *s, const char *eos) #undef NEXT_LINE } +static inline int +policy_is_reject_star_or_null(struct short_policy_t *policy) +{ + return !policy || short_policy_is_reject_star(policy); +} + +/** + * Return a human-readable description of a given saved_location_t. + * Never returns NULL. + **/ +static const char * +saved_location_to_string(saved_location_t where) +{ + const char *location; + switch (where) { + case SAVED_NOWHERE: + location = "download or generated string"; + break; + case SAVED_IN_CACHE: + location = "cache"; + break; + case SAVED_IN_JOURNAL: + location = "journal"; + break; + default: + location = "unknown location"; + break; + } + return location; +} + +/** + * Given a microdescriptor stored in <b>where</b> which starts at <b>s</b>, + * which ends at <b>start_of_next_microdescriptor</b>, and which is located + * within a larger document beginning at <b>start</b>: Fill in the body, + * bodylen, bodylen, saved_location, off, and digest fields of <b>md</b> as + * appropriate. + * + * The body field will be an alias within <b>s</b> if <b>saved_location</b> + * is SAVED_IN_CACHE, and will be copied into body and nul-terminated + * otherwise. + **/ +static int +microdesc_extract_body(microdesc_t *md, + const char *start, + const char *s, const char *start_of_next_microdesc, + saved_location_t where) +{ + const bool copy_body = (where != SAVED_IN_CACHE); + + const char *cp = tor_memstr(s, start_of_next_microdesc-s, "onion-key"); + + const bool 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); + + return no_onion_key ? -1 : 0; +} + +/** + * Parse a microdescriptor which begins at <b>s</b> and ends at + * <b>start_of_next_microdesc</b>. Store its fields into <b>md</b>. Use + * <b>where</b> for generating log information. If <b>allow_annotations</b> + * is true, then one or more annotations may precede the microdescriptor body + * proper. Use <b>area</b> for memory management, clearing it when done. + * + * On success, return 0; otherwise return -1. + **/ +static int +microdesc_parse_fields(microdesc_t *md, + memarea_t *area, + const char *s, const char *start_of_next_microdesc, + int allow_annotations, + saved_location_t where) +{ + smartlist_t *tokens = smartlist_new(); + int rv = -1; + int flags = allow_annotations ? TS_ANNOTATIONS_OK : 0; + directory_token_t *tok; + + if (tokenize_string(area, s, start_of_next_microdesc, tokens, + microdesc_token_table, flags)) { + log_warn(LD_DIR, "Unparseable microdescriptor found in %s", + saved_location_to_string(where)); + goto err; + } + + 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 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; + } + md->onion_pkey = tor_memdup(tok->object_body, tok->object_size); + md->onion_pkey_len = tok->object_size; + 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 err; + } + 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 err; + } + 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 err; + } + 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))) { + md->family = nodefamily_parse(tok->args[0], + NULL, + NF_WARN_MALFORMED); + } + + 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]); + } + + if (policy_is_reject_star_or_null(md->exit_policy) && + policy_is_reject_star_or_null(md->ipv6_exit_policy)) { + md->policy_is_reject_star = 1; + } + + rv = 0; + err: + + SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t)); + memarea_clear(area); + smartlist_free(tokens); + + return rv; +} + /** 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. @@ -108,16 +295,11 @@ microdescs_parse_from_string(const char *s, const char *eos, 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); @@ -125,143 +307,47 @@ microdescs_parse_from_string(const char *s, const char *eos, s = eat_whitespace_eos(s, eos); area = memarea_new(); result = smartlist_new(); - tokens = smartlist_new(); while (s < eos) { - int okay = 0; + bool okay = false; 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)); + uint8_t md_digest[DIGEST256_LEN]; { - 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 */ - } + const bool body_not_found = + microdesc_extract_body(md, start, s, + start_of_next_microdesc, + where) < 0; - 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) { + memcpy(md_digest, md->digest, DIGEST256_LEN); + if (body_not_found) { 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 (microdesc_parse_fields(md, area, s, start_of_next_microdesc, + allow_annotations, where) == 0) { + smartlist_add(result, md); + md = NULL; // prevent free + okay = true; } - 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)); + 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; } |