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+/* Copyright (c) 2001 Matej Pfajfar.
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+ * Copyright (c) 2001-2004, Roger Dingledine.
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+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
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+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
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+/* See LICENSE for licensing information */
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+
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+/**
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+ * \file microdesc_parse.c
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+ * \brief Code to parse and validate microdescriptors.
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+ **/
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+
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+#include "core/or/or.h"
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+
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+#include "app/config/config.h"
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+#include "core/or/policies.h"
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+#include "feature/dirparse/microdesc_parse.h"
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+#include "feature/dirparse/parsecommon.h"
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+#include "feature/dirparse/routerparse.h"
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+#include "feature/nodelist/microdesc.h"
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+#include "feature/nodelist/nickname.h"
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+#include "feature/relay/router.h"
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+#include "lib/crypt_ops/crypto_curve25519.h"
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+#include "lib/crypt_ops/crypto_ed25519.h"
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+#include "lib/crypt_ops/crypto_format.h"
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+#include "lib/memarea/memarea.h"
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+
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+#include "feature/nodelist/microdesc_st.h"
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+
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+/** List of tokens recognized in microdescriptors */
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+static token_rule_t microdesc_token_table[] = {
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+ T1_START("onion-key", K_ONION_KEY, NO_ARGS, NEED_KEY_1024),
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+ T01("ntor-onion-key", K_ONION_KEY_NTOR, GE(1), NO_OBJ ),
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+ T0N("id", K_ID, GE(2), NO_OBJ ),
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+ T0N("a", K_A, GE(1), NO_OBJ ),
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+ T01("family", K_FAMILY, ARGS, NO_OBJ ),
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+ T01("p", K_P, CONCAT_ARGS, NO_OBJ ),
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+ T01("p6", K_P6, CONCAT_ARGS, NO_OBJ ),
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+ A01("@last-listed", A_LAST_LISTED, CONCAT_ARGS, NO_OBJ ),
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+ END_OF_TABLE
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+};
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+
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+/** Assuming that s starts with a microdesc, return the start of the
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+ * *NEXT* one. Return NULL on "not found." */
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+static const char *
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+find_start_of_next_microdesc(const char *s, const char *eos)
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+{
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+ int started_with_annotations;
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+ s = eat_whitespace_eos(s, eos);
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+ if (!s)
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+ return NULL;
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+
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+#define CHECK_LENGTH() STMT_BEGIN \
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+ if (s+32 > eos) \
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+ return NULL; \
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+ STMT_END
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+
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+#define NEXT_LINE() STMT_BEGIN \
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+ s = memchr(s, '\n', eos-s); \
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+ if (!s || s+1 >= eos) \
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+ return NULL; \
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+ s++; \
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+ STMT_END
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+
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+ CHECK_LENGTH();
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+
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+ started_with_annotations = (*s == '@');
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+
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+ if (started_with_annotations) {
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+ /* Start by advancing to the first non-annotation line. */
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+ while (*s == '@')
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+ NEXT_LINE();
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+ }
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+ CHECK_LENGTH();
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+
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+ /* Now we should be pointed at an onion-key line. If we are, then skip
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+ * it. */
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+ if (!strcmpstart(s, "onion-key"))
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+ NEXT_LINE();
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+
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+ /* Okay, now we're pointed at the first line of the microdescriptor which is
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+ not an annotation or onion-key. The next line that _is_ an annotation or
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+ onion-key is the start of the next microdescriptor. */
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+ while (s+32 < eos) {
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+ if (*s == '@' || !strcmpstart(s, "onion-key"))
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+ return s;
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+ NEXT_LINE();
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+ }
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+ return NULL;
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+
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+#undef CHECK_LENGTH
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+#undef NEXT_LINE
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+}
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+
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+/** Parse as many microdescriptors as are found from the string starting at
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+ * <b>s</b> and ending at <b>eos</b>. If allow_annotations is set, read any
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+ * annotations we recognize and ignore ones we don't.
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+ *
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+ * If <b>saved_location</b> isn't SAVED_IN_CACHE, make a local copy of each
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+ * descriptor in the body field of each microdesc_t.
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+ *
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+ * Return all newly parsed microdescriptors in a newly allocated
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+ * smartlist_t. If <b>invalid_disgests_out</b> is provided, add a SHA256
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+ * microdesc digest to it for every microdesc that we found to be badly
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+ * formed. (This may cause duplicates) */
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+smartlist_t *
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+microdescs_parse_from_string(const char *s, const char *eos,
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+ int allow_annotations,
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+ saved_location_t where,
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+ smartlist_t *invalid_digests_out)
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+{
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+ smartlist_t *tokens;
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+ smartlist_t *result;
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+ microdesc_t *md = NULL;
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+ memarea_t *area;
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+ const char *start = s;
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+ const char *start_of_next_microdesc;
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+ int flags = allow_annotations ? TS_ANNOTATIONS_OK : 0;
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+ const int copy_body = (where != SAVED_IN_CACHE);
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+
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+ directory_token_t *tok;
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+
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+ if (!eos)
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+ eos = s + strlen(s);
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+
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+ s = eat_whitespace_eos(s, eos);
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+ area = memarea_new();
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+ result = smartlist_new();
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+ tokens = smartlist_new();
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+
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+ while (s < eos) {
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+ int okay = 0;
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+
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+ start_of_next_microdesc = find_start_of_next_microdesc(s, eos);
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+ if (!start_of_next_microdesc)
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+ start_of_next_microdesc = eos;
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+
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+ md = tor_malloc_zero(sizeof(microdesc_t));
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+ {
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+ const char *cp = tor_memstr(s, start_of_next_microdesc-s,
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+ "onion-key");
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+ const int no_onion_key = (cp == NULL);
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+ if (no_onion_key) {
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+ cp = s; /* So that we have *some* junk to put in the body */
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+ }
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+
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+ md->bodylen = start_of_next_microdesc - cp;
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+ md->saved_location = where;
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+ if (copy_body)
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+ md->body = tor_memdup_nulterm(cp, md->bodylen);
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+ else
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+ md->body = (char*)cp;
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+ md->off = cp - start;
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+ crypto_digest256(md->digest, md->body, md->bodylen, DIGEST_SHA256);
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+ if (no_onion_key) {
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+ log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Malformed or truncated descriptor");
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+ goto next;
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+ }
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+ }
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+
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+ if (tokenize_string(area, s, start_of_next_microdesc, tokens,
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+ microdesc_token_table, flags)) {
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+ log_warn(LD_DIR, "Unparseable microdescriptor");
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+ goto next;
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+ }
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+
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+ if ((tok = find_opt_by_keyword(tokens, A_LAST_LISTED))) {
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+ if (parse_iso_time(tok->args[0], &md->last_listed)) {
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+ log_warn(LD_DIR, "Bad last-listed time in microdescriptor");
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+ goto next;
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+ }
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+ }
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+
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+ tok = find_by_keyword(tokens, K_ONION_KEY);
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+ if (!crypto_pk_public_exponent_ok(tok->key)) {
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+ log_warn(LD_DIR,
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+ "Relay's onion key had invalid exponent.");
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+ goto next;
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+ }
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+ router_set_rsa_onion_pkey(tok->key, &md->onion_pkey,
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+ &md->onion_pkey_len);
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+ crypto_pk_free(tok->key);
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+
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+ if ((tok = find_opt_by_keyword(tokens, K_ONION_KEY_NTOR))) {
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+ curve25519_public_key_t k;
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+ tor_assert(tok->n_args >= 1);
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+ if (curve25519_public_from_base64(&k, tok->args[0]) < 0) {
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+ log_warn(LD_DIR, "Bogus ntor-onion-key in microdesc");
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+ goto next;
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+ }
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+ md->onion_curve25519_pkey =
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+ tor_memdup(&k, sizeof(curve25519_public_key_t));
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+ }
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+
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+ smartlist_t *id_lines = find_all_by_keyword(tokens, K_ID);
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+ if (id_lines) {
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+ SMARTLIST_FOREACH_BEGIN(id_lines, directory_token_t *, t) {
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+ tor_assert(t->n_args >= 2);
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+ if (!strcmp(t->args[0], "ed25519")) {
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+ if (md->ed25519_identity_pkey) {
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+ log_warn(LD_DIR, "Extra ed25519 key in microdesc");
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+ smartlist_free(id_lines);
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+ goto next;
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+ }
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+ ed25519_public_key_t k;
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+ if (ed25519_public_from_base64(&k, t->args[1])<0) {
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+ log_warn(LD_DIR, "Bogus ed25519 key in microdesc");
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+ smartlist_free(id_lines);
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+ goto next;
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+ }
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+ md->ed25519_identity_pkey = tor_memdup(&k, sizeof(k));
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+ }
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+ } SMARTLIST_FOREACH_END(t);
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+ smartlist_free(id_lines);
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+ }
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+
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+ {
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+ smartlist_t *a_lines = find_all_by_keyword(tokens, K_A);
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+ if (a_lines) {
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+ find_single_ipv6_orport(a_lines, &md->ipv6_addr, &md->ipv6_orport);
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+ smartlist_free(a_lines);
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+ }
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+ }
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+
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+ if ((tok = find_opt_by_keyword(tokens, K_FAMILY))) {
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+ int i;
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+ md->family = smartlist_new();
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+ for (i=0;i<tok->n_args;++i) {
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+ if (!is_legal_nickname_or_hexdigest(tok->args[i])) {
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+ log_warn(LD_DIR, "Illegal nickname %s in family line",
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+ escaped(tok->args[i]));
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+ goto next;
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+ }
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+ smartlist_add_strdup(md->family, tok->args[i]);
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+ }
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+ }
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+
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+ if ((tok = find_opt_by_keyword(tokens, K_P))) {
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+ md->exit_policy = parse_short_policy(tok->args[0]);
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+ }
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+ if ((tok = find_opt_by_keyword(tokens, K_P6))) {
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+ md->ipv6_exit_policy = parse_short_policy(tok->args[0]);
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+ }
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+
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+ smartlist_add(result, md);
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+ okay = 1;
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+
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+ md = NULL;
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+ next:
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+ if (! okay && invalid_digests_out) {
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+ smartlist_add(invalid_digests_out,
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+ tor_memdup(md->digest, DIGEST256_LEN));
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+ }
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+ microdesc_free(md);
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+ md = NULL;
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+
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+ SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
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+ memarea_clear(area);
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+ smartlist_clear(tokens);
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+ s = start_of_next_microdesc;
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+ }
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+
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+ SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
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+ memarea_drop_all(area);
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+ smartlist_free(tokens);
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+
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+ return result;
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+}
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Nick Mathewson