Merge branch 'tor-github/pr/1309' (99f75373) · Commits · David Goulet / Tor

changes/ticket31675

0 → 100644

+3 −0

Original line number	Diff line number	Diff line
		o Code simplification and refactoring:
		- Refactor the microdescs_parse_from_string() function into smaller
		pieces, for better comprehensibility. Closes ticket 31675.

scripts/maint/practracker/exceptions.txt

+0 −1

Original line number	Diff line number	Diff line
		@@ -227,7 +227,6 @@ problem function-size /src/feature/dirclient/dirclient.c:handle_response_fetch_c
		problem function-size /src/feature/dircommon/consdiff.c:gen_ed_diff() 203
		problem function-size /src/feature/dircommon/consdiff.c:apply_ed_diff() 158
		problem function-size /src/feature/dirparse/authcert_parse.c:authority_cert_parse_from_string() 181
		problem function-size /src/feature/dirparse/microdesc_parse.c:microdescs_parse_from_string() 166
		problem function-size /src/feature/dirparse/ns_parse.c:routerstatus_parse_entry_from_string() 280
		problem function-size /src/feature/dirparse/ns_parse.c:networkstatus_verify_bw_weights() 389
		problem function-size /src/feature/dirparse/ns_parse.c:networkstatus_parse_vote_from_string() 635

src/feature/dirparse/microdesc_parse.c

+192 −128

Original line number	Diff line number	Diff line
		@@ -98,54 +98,53 @@ policy_is_reject_star_or_null(struct short_policy_t *policy)
		return !policy \|\| short_policy_is_reject_star(policy);
		}

		/** 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)
		/**
		* 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)
		{
		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();
		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;
		}

		while (s < eos) {
		int okay = 0;
		/**
		* 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);

		start_of_next_microdesc = find_start_of_next_microdesc(s, eos);
		if (!start_of_next_microdesc)
		start_of_next_microdesc = eos;
		const char *cp = tor_memstr(s, start_of_next_microdesc-s, "onion-key");

		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);
		const bool no_onion_key = (cp == NULL);
		if (no_onion_key) {
		cp = s; /* So that we have some junk to put in the body */
		}
		@@ -157,38 +156,44 @@ microdescs_parse_from_string(const char s, const char eos,
		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;
		}

		return no_onion_key ? -1 : 0;
		}

		/**
		* Parse a microdescriptor which begins at <b>s</b> and ends at
		* <b>start_of_next_microdesc. 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)) {
		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;
		}
		log_warn(LD_DIR, "Unparseable microdescriptor found in %s", location);
		goto next;
		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 next;
		goto err;
		}
		}

		@@ -196,7 +201,7 @@ microdescs_parse_from_string(const char s, const char eos,
		if (!crypto_pk_public_exponent_ok(tok->key)) {
		log_warn(LD_DIR,
		"Relay's onion key had invalid exponent.");
		goto next;
		goto err;
		}
		md->onion_pkey = tor_memdup(tok->object_body, tok->object_size);
		md->onion_pkey_len = tok->object_size;
		@@ -207,7 +212,7 @@ microdescs_parse_from_string(const char s, const char eos,
		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;
		goto err;
		}
		md->onion_curve25519_pkey =
		tor_memdup(&k, sizeof(curve25519_public_key_t));
		@@ -221,13 +226,13 @@ microdescs_parse_from_string(const char s, const char eos,
		if (md->ed25519_identity_pkey) {
		log_warn(LD_DIR, "Extra ed25519 key in microdesc");
		smartlist_free(id_lines);
		goto next;
		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 next;
		goto err;
		}
		md->ed25519_identity_pkey = tor_memdup(&k, sizeof(k));
		}
		@@ -261,27 +266,86 @@ microdescs_parse_from_string(const char s, const char eos,
		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.
		*
		* 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 *result;
		microdesc_t *md = NULL;
		memarea_t *area;
		const char *start = s;
		const char *start_of_next_microdesc;

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

		s = eat_whitespace_eos(s, eos);
		area = memarea_new();
		result = smartlist_new();

		while (s < eos) {
		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 bool body_not_found =
		microdesc_extract_body(md, start, s,
		start_of_next_microdesc,
		where) < 0;

		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 (microdesc_parse_fields(md, area, s, start_of_next_microdesc,
		allow_annotations, where) == 0) {
		smartlist_add(result, md);
		okay = 1;
		md = NULL; // prevent free
		okay = true;
		}

		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;
		}

src/test/test_microdesc.c

+76 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@
		#include "feature/nodelist/routerstatus_st.h"

		#include "test/test.h"
		#include "test/log_test_helpers.h"

		#ifdef HAVE_SYS_STAT_H
		#include <sys/stat.h>
		@@ -770,6 +771,80 @@ test_md_parse(void *arg)
		tor_free(mem_op_hex_tmp);
		}

		static void
		test_md_parse_id_ed25519(void *arg)
		{
		(void)arg;

		/* A correct MD with an ed25519 ID ... and an unspecified ID type,
		* which is permitted. */
		const char GOOD_MD[] =
		"onion-key\n"
		"-----BEGIN RSA PUBLIC KEY-----\n"
		"MIGJAoGBAM7uUtq5F6h63QNYIvC+4NcWaD0DjtnrOORZMkdpJhinXUOwce3cD5Dj\n"
		"sgdN1wJpWpTQMXJ2DssfSgmOVXETP7qJuZyRprxalQhaEATMDNJA/66Ml1jSO9mZ\n"
		"+8Xb7m/4q778lNtkSbsvMaYD2Dq6k2QQ3kMhr9z8oUtX0XA23+pfAgMBAAE=\n"
		"-----END RSA PUBLIC KEY-----\n"
		"id ed25519 VGhpcyBpc24ndCBhY3R1YWxseSBhIHB1YmxpYyBrZXk\n"
		"id wumpus dodecahedron\n";

		smartlist_t *mds = NULL;
		const microdesc_t *md;

		mds = microdescs_parse_from_string(GOOD_MD,
		NULL, 1, SAVED_NOWHERE, NULL);
		tt_assert(mds);
		tt_int_op(smartlist_len(mds), OP_EQ, 1);
		md = smartlist_get(mds, 0);
		tt_mem_op(md->ed25519_identity_pkey, OP_EQ,
		"This isn't actually a public key", ED25519_PUBKEY_LEN);
		SMARTLIST_FOREACH(mds, microdesc_t *, m, microdesc_free(m));
		smartlist_free(mds);

		/* As above, but ed25519 ID key appears twice. */
		const char DUPLICATE_KEY[] =
		"onion-key\n"
		"-----BEGIN RSA PUBLIC KEY-----\n"
		"MIGJAoGBAM7uUtq5F6h63QNYIvC+4NcWaD0DjtnrOORZMkdpJhinXUOwce3cD5Dj\n"
		"sgdN1wJpWpTQMXJ2DssfSgmOVXETP7qJuZyRprxalQhaEATMDNJA/66Ml1jSO9mZ\n"
		"+8Xb7m/4q778lNtkSbsvMaYD2Dq6k2QQ3kMhr9z8oUtX0XA23+pfAgMBAAE=\n"
		"-----END RSA PUBLIC KEY-----\n"
		"id ed25519 VGhpcyBpc24ndCBhY3R1YWxseSBhIHB1YmxpYyBrZXk\n"
		"id ed25519 VGhpcyBpc24ndCBhY3R1YWxseSBhIHB1YmxpYyBrZXk\n";

		setup_capture_of_logs(LOG_WARN);
		mds = microdescs_parse_from_string(DUPLICATE_KEY,
		NULL, 1, SAVED_NOWHERE, NULL);
		tt_assert(mds);
		tt_int_op(smartlist_len(mds), OP_EQ, 0); // no entries.
		expect_single_log_msg_containing("Extra ed25519 key");
		mock_clean_saved_logs();
		smartlist_free(mds);

		/* As above, but ed25519 ID key is invalid. */
		const char BOGUS_KEY[] =
		"onion-key\n"
		"-----BEGIN RSA PUBLIC KEY-----\n"
		"MIGJAoGBAM7uUtq5F6h63QNYIvC+4NcWaD0DjtnrOORZMkdpJhinXUOwce3cD5Dj\n"
		"sgdN1wJpWpTQMXJ2DssfSgmOVXETP7qJuZyRprxalQhaEATMDNJA/66Ml1jSO9mZ\n"
		"+8Xb7m/4q778lNtkSbsvMaYD2Dq6k2QQ3kMhr9z8oUtX0XA23+pfAgMBAAE=\n"
		"-----END RSA PUBLIC KEY-----\n"
		"id ed25519 VGhpcyBpc24ndCBhY3R1YWxseSBhIHB1YmxpYyZZZZZZZZZZZ\n";

		mds = microdescs_parse_from_string(BOGUS_KEY,
		NULL, 1, SAVED_NOWHERE, NULL);
		tt_assert(mds);
		tt_int_op(smartlist_len(mds), OP_EQ, 0); // no entries.
		expect_single_log_msg_containing("Bogus ed25519 key");

		done:
		if (mds) {
		SMARTLIST_FOREACH(mds, microdesc_t *, m, microdesc_free(m));
		smartlist_free(mds);
		}
		teardown_capture_of_logs();
		}

		static int mock_rgsbd_called = 0;
		static routerstatus_t *mock_rgsbd_val_a = NULL;
		static routerstatus_t *mock_rgsbd_val_b = NULL;
		@@ -903,6 +978,7 @@ struct testcase_t microdesc_tests[] = {
		{ "broken_cache", test_md_cache_broken, TT_FORK, NULL, NULL },
		{ "generate", test_md_generate, 0, NULL, NULL },
		{ "parse", test_md_parse, 0, NULL, NULL },
		{ "parse_id_ed25519", test_md_parse_id_ed25519, 0, NULL, NULL },
		{ "reject_cache", test_md_reject_cache, TT_FORK, NULL, NULL },
		{ "corrupt_desc", test_md_corrupt_desc, TT_FORK, NULL, NULL },
		END_OF_TESTCASES