mirror of
https://gitlab.torproject.org/tpo/core/tor.git
synced 2024-11-10 13:13:44 +01:00
Refactor dirobj signature generation
Now we can compute the hash and signature of a dirobj before concatenating the smartlist, and we don't need to play silly games with sigbuf and realloc any more.
This commit is contained in:
parent
fd93622cc8
commit
cb75519bbf
@ -1631,6 +1631,29 @@ crypto_digest_assign(crypto_digest_t *into,
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memcpy(into,from,sizeof(crypto_digest_t));
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}
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/** Given a list of strings in <b>lst</b>, set the <b>len_out</b>-byte digest
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* at <b>digest_out</b> to the hash of the concatenation of those strings,
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* plus the optional string <b>append</b>, computed with the algorithm
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* <b>alg</b>. */
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void
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crypto_digest_smartlist(char *digest_out, size_t len_out,
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const smartlist_t *lst, const char *append,
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digest_algorithm_t alg)
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{
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crypto_digest_t *d;
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if (alg == DIGEST_SHA1)
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d = crypto_digest_new();
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else
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d = crypto_digest256_new(alg);
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SMARTLIST_FOREACH(lst, const char *, cp,
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crypto_digest_add_bytes(d, cp, strlen(cp)));
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if (append)
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crypto_digest_add_bytes(d, append, strlen(append));
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crypto_digest_get_digest(d, digest_out, len_out);
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crypto_digest_free(d);
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}
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/** Compute the HMAC-SHA-1 of the <b>msg_len</b> bytes in <b>msg</b>, using
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* the <b>key</b> of length <b>key_len</b>. Store the DIGEST_LEN-byte result
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* in <b>hmac_out</b>.
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@ -206,6 +206,10 @@ int crypto_digest(char *digest, const char *m, size_t len);
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int crypto_digest256(char *digest, const char *m, size_t len,
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digest_algorithm_t algorithm);
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int crypto_digest_all(digests_t *ds_out, const char *m, size_t len);
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struct smartlist_t;
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void crypto_digest_smartlist(char *digest_out, size_t len_out,
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const struct smartlist_t *lst, const char *append,
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digest_algorithm_t alg);
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const char *crypto_digest_algorithm_get_name(digest_algorithm_t alg);
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int crypto_digest_algorithm_parse_name(const char *name);
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crypto_digest_t *crypto_digest_new(void);
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@ -2911,7 +2911,6 @@ generate_v2_networkstatus_opinion(void)
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size_t identity_pkey_len;
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char *status = NULL, *client_versions = NULL, *server_versions = NULL,
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*identity_pkey = NULL, *hostname = NULL;
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size_t status_len;
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const or_options_t *options = get_options();
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char fingerprint[FINGERPRINT_LEN+1];
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char published[ISO_TIME_LEN+1];
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@ -3032,23 +3031,21 @@ generate_v2_networkstatus_opinion(void)
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smartlist_add_asprintf(chunks, "directory-signature %s\n",
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options->Nickname);
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status = smartlist_join_strings(chunks, "", 0, NULL);
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#define MAX_V2_OPINION_SIGNATURE_LEN 4096
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status_len = strlen(status) + MAX_V2_OPINION_SIGNATURE_LEN + 1;
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status = tor_realloc(status, status_len);
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if (router_get_networkstatus_v2_hash(status, digest)<0) {
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log_warn(LD_BUG, "Unable to hash network status");
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goto done;
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}
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crypto_digest_smartlist(digest, DIGEST_LEN, chunks, "", DIGEST_SHA1);
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note_crypto_pk_op(SIGN_DIR);
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if (router_append_dirobj_signature(status, status_len,digest,DIGEST_LEN,
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private_key)<0) {
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log_warn(LD_BUG, "Unable to sign router status.");
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goto done;
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{
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char *sig;
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if (!(sig = router_get_dirobj_signature(digest,DIGEST_LEN,
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private_key))) {
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log_warn(LD_BUG, "Unable to sign router status.");
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goto done;
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}
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smartlist_add(chunks, sig);
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}
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status = smartlist_join_strings(chunks, "", 0, NULL);
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{
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networkstatus_v2_t *ns;
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if (!(ns = networkstatus_v2_parse_from_string(status))) {
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@ -75,7 +75,6 @@ format_networkstatus_vote(crypto_pk_t *private_signing_key,
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char *client_versions_line = NULL, *server_versions_line = NULL;
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networkstatus_voter_info_t *voter;
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char *status = NULL;
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size_t status_len;
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tor_assert(private_signing_key);
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tor_assert(v3_ns->type == NS_TYPE_VOTE || v3_ns->type == NS_TYPE_OPINION);
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@ -185,6 +184,11 @@ format_networkstatus_vote(crypto_pk_t *private_signing_key,
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smartlist_add(chunks, tor_strdup("directory-footer\n"));
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/* The digest includes everything up through the space after
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* directory-signature. (Yuck.) */
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crypto_digest_smartlist(digest, DIGEST_LEN, chunks,
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"directory-signature ", DIGEST_SHA1);
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{
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char signing_key_fingerprint[FINGERPRINT_LEN+1];
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if (crypto_pk_get_fingerprint(private_signing_key,
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@ -197,22 +201,19 @@ format_networkstatus_vote(crypto_pk_t *private_signing_key,
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signing_key_fingerprint);
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}
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status = smartlist_join_strings(chunks, "", 0, NULL);
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#define MAX_VOTE_SIGNATURE_LEN 4096
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status_len = strlen(status) + MAX_VOTE_SIGNATURE_LEN + 1;
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status = tor_realloc(status, status_len);
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if (router_get_networkstatus_v3_hash(status, digest, DIGEST_SHA1)<0)
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goto err;
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note_crypto_pk_op(SIGN_DIR);
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if (router_append_dirobj_signature(status+strlen(status),
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status_len,
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digest, DIGEST_LEN,
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private_signing_key)<0) {
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log_warn(LD_BUG, "Unable to sign networkstatus vote.");
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goto err;
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{
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char *sig = router_get_dirobj_signature(digest, DIGEST_LEN,
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private_signing_key);
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if (!sig) {
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log_warn(LD_BUG, "Unable to sign networkstatus vote.");
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goto err;
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}
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smartlist_add(chunks, sig);
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}
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status = smartlist_join_strings(chunks, "", 0, NULL);
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{
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networkstatus_t *v;
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if (!(v = networkstatus_parse_vote_from_string(status, NULL,
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@ -479,24 +480,6 @@ compute_routerstatus_consensus(smartlist_t *votes, int consensus_method,
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return most;
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}
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/** Given a list of strings in <b>lst</b>, set the <b>len_out</b>-byte digest
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* at <b>digest_out</b> to the hash of the concatenation of those strings,
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* computed with the algorithm <b>alg</b>. */
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static void
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hash_list_members(char *digest_out, size_t len_out,
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smartlist_t *lst, digest_algorithm_t alg)
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{
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crypto_digest_t *d;
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if (alg == DIGEST_SHA1)
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d = crypto_digest_new();
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else
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d = crypto_digest256_new(alg);
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SMARTLIST_FOREACH(lst, const char *, cp,
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crypto_digest_add_bytes(d, cp, strlen(cp)));
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crypto_digest_get_digest(d, digest_out, len_out);
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crypto_digest_free(d);
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}
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/** Sorting helper: compare two strings based on their values as base-ten
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* positive integers. (Non-integers are treated as prior to all integers, and
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* compared lexically.) */
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@ -2095,12 +2078,12 @@ networkstatus_compute_consensus(smartlist_t *votes,
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size_t digest_len =
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flavor == FLAV_NS ? DIGEST_LEN : DIGEST256_LEN;
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const char *algname = crypto_digest_algorithm_get_name(digest_alg);
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char sigbuf[4096];
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char *signature;
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smartlist_add(chunks, tor_strdup("directory-signature "));
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/* Compute the hash of the chunks. */
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hash_list_members(digest, digest_len, chunks, digest_alg);
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crypto_digest_smartlist(digest, digest_len, chunks, "", digest_alg);
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/* Get the fingerprints */
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crypto_pk_get_fingerprint(identity_key, fingerprint, 0);
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@ -2116,14 +2099,12 @@ networkstatus_compute_consensus(smartlist_t *votes,
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signing_key_fingerprint);
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}
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/* And the signature. */
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sigbuf[0] = '\0';
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if (router_append_dirobj_signature(sigbuf, sizeof(sigbuf),
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digest, digest_len,
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signing_key)) {
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if (!(signature = router_get_dirobj_signature(digest, digest_len,
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signing_key))) {
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log_warn(LD_BUG, "Couldn't sign consensus networkstatus.");
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goto done;
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}
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smartlist_add(chunks, tor_strdup(sigbuf));
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smartlist_add(chunks, signature);
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if (legacy_id_key_digest && legacy_signing_key && consensus_method >= 3) {
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smartlist_add(chunks, tor_strdup("directory-signature "));
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@ -2139,14 +2120,13 @@ networkstatus_compute_consensus(smartlist_t *votes,
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algname, fingerprint,
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signing_key_fingerprint);
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}
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sigbuf[0] = '\0';
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if (router_append_dirobj_signature(sigbuf, sizeof(sigbuf),
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digest, digest_len,
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legacy_signing_key)) {
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if (!(signature = router_get_dirobj_signature(digest, digest_len,
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legacy_signing_key))) {
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log_warn(LD_BUG, "Couldn't sign consensus networkstatus.");
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goto done;
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}
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smartlist_add(chunks, tor_strdup(sigbuf));
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smartlist_add(chunks, signature);
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}
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}
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@ -2248,7 +2248,6 @@ router_dump_router_to_string(routerinfo_t *router,
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const or_options_t *options = get_options();
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smartlist_t *chunks = NULL;
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char *output = NULL;
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size_t output_len;
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/* Make sure the identity key matches the one in the routerinfo. */
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if (!crypto_pk_eq_keys(ident_key, router->identity_pkey)) {
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@ -2395,24 +2394,22 @@ router_dump_router_to_string(routerinfo_t *router,
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/* Sign the descriptor */
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smartlist_add(chunks, tor_strdup("router-signature\n"));
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output = smartlist_join_strings(chunks, "", 0, NULL);
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#define MAX_DESC_SIGNATURE_LEN 4096
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output_len = strlen(output) + MAX_DESC_SIGNATURE_LEN + 1;
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output = tor_realloc(output, output_len);
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if (router_get_router_hash(output, strlen(output), digest) < 0) {
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goto err;
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}
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crypto_digest_smartlist(digest, DIGEST_LEN, chunks, "", DIGEST_SHA1);
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note_crypto_pk_op(SIGN_RTR);
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if (router_append_dirobj_signature(output, output_len,
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digest,DIGEST_LEN,ident_key)<0) {
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log_warn(LD_BUG, "Couldn't sign router descriptor");
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goto err;
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{
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char *sig;
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if (!(sig = router_get_dirobj_signature(digest, DIGEST_LEN, ident_key))) {
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log_warn(LD_BUG, "Couldn't sign router descriptor");
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goto err;
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}
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smartlist_add(chunks, sig);
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}
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/* include a last '\n' */
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strlcat(output, "\n", output_len);
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smartlist_add(chunks, tor_strdup("\n"));
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output = smartlist_join_strings(chunks, "", 0, NULL);
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#ifdef DEBUG_ROUTER_DUMP_ROUTER_TO_STRING
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{
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@ -683,20 +683,19 @@ router_get_extrainfo_hash(const char *s, size_t s_len, char *digest)
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"\nrouter-signature",'\n', DIGEST_SHA1);
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}
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/** Helper: used to generate signatures for routers, directories and
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* network-status objects. Given a digest in <b>digest</b> and a secret
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* <b>private_key</b>, generate an PKCS1-padded signature, BASE64-encode it,
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* surround it with -----BEGIN/END----- pairs, and write it to the
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* <b>buf_len</b>-byte buffer at <b>buf</b>. Return 0 on success, -1 on
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* failure.
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*/
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int
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router_append_dirobj_signature(char *buf, size_t buf_len, const char *digest,
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size_t digest_len, crypto_pk_t *private_key)
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/** DOCDOC */
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char *
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router_get_dirobj_signature(const char *digest,
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size_t digest_len,
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crypto_pk_t *private_key)
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{
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char *signature;
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size_t i, keysize;
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int siglen;
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char *buf = NULL;
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size_t buf_len;
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/* overestimate of BEGIN/END lines total len. */
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#define BEGIN_END_OVERHEAD_LEN 64
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keysize = crypto_pk_keysize(private_key);
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signature = tor_malloc(keysize);
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@ -706,7 +705,12 @@ router_append_dirobj_signature(char *buf, size_t buf_len, const char *digest,
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log_warn(LD_BUG,"Couldn't sign digest.");
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goto err;
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}
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if (strlcat(buf, "-----BEGIN SIGNATURE-----\n", buf_len) >= buf_len)
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/* The *2 here is a ridiculous overestimate of base-64 overhead. */
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buf_len = (siglen * 2) + BEGIN_END_OVERHEAD_LEN;
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buf = tor_malloc(buf_len);
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if (strlcpy(buf, "-----BEGIN SIGNATURE-----\n", buf_len) >= buf_len)
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goto truncated;
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i = strlen(buf);
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@ -719,13 +723,42 @@ router_append_dirobj_signature(char *buf, size_t buf_len, const char *digest,
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goto truncated;
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tor_free(signature);
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return 0;
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return buf;
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truncated:
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log_warn(LD_BUG,"tried to exceed string length.");
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err:
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tor_free(signature);
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return -1;
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tor_free(buf);
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return NULL;
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}
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/** Helper: used to generate signatures for routers, directories and
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* network-status objects. Given a digest in <b>digest</b> and a secret
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* <b>private_key</b>, generate an PKCS1-padded signature, BASE64-encode it,
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* surround it with -----BEGIN/END----- pairs, and write it to the
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* <b>buf_len</b>-byte buffer at <b>buf</b>. Return 0 on success, -1 on
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* failure.
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*/
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int
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router_append_dirobj_signature(char *buf, size_t buf_len, const char *digest,
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size_t digest_len, crypto_pk_t *private_key)
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{
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size_t sig_len, s_len;
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char *sig = router_get_dirobj_signature(digest, digest_len, private_key);
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if (!sig) {
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log_warn(LD_BUG, "No signature generated");
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return -1;
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}
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sig_len = strlen(sig);
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s_len = strlen(buf);
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if (sig_len + s_len + 1 > buf_len) {
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log_warn(LD_BUG, "Not enough room for signature");
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tor_free(sig);
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return -1;
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}
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memcpy(buf+s_len, sig, sig_len+1);
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return 0;
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}
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/** Return VS_RECOMMENDED if <b>myversion</b> is contained in
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@ -21,6 +21,9 @@ int router_get_networkstatus_v3_hash(const char *s, char *digest,
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int router_get_networkstatus_v3_hashes(const char *s, digests_t *digests);
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int router_get_extrainfo_hash(const char *s, size_t s_len, char *digest);
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#define DIROBJ_MAX_SIG_LEN 256
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char *router_get_dirobj_signature(const char *digest,
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size_t digest_len,
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crypto_pk_t *private_key);
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int router_append_dirobj_signature(char *buf, size_t buf_len,
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const char *digest,
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size_t digest_len,
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