Use chunks, not buffers, for router descriptors

This commit is contained in:
Nick Mathewson 2013-02-22 12:17:23 -05:00
parent 1186628fa9
commit fd93622cc8
3 changed files with 67 additions and 92 deletions

View File

@ -1927,9 +1927,8 @@ router_rebuild_descriptor(int force)
/* ri was allocated with tor_malloc_zero, so there is no need to
* zero ri->cache_info.extra_info_digest here. */
}
ri->cache_info.signed_descriptor_body = tor_malloc(8192);
if (router_dump_router_to_string(ri->cache_info.signed_descriptor_body, 8192,
ri, get_server_identity_key()) < 0) {
if (! (ri->cache_info.signed_descriptor_body = router_dump_router_to_string(
ri, get_server_identity_key()))) {
log_warn(LD_BUG, "Couldn't generate router descriptor.");
routerinfo_free(ri);
extrainfo_free(ei);
@ -2229,54 +2228,53 @@ get_platform_str(char *platform, size_t len)
#define DEBUG_ROUTER_DUMP_ROUTER_TO_STRING
/** OR only: Given a routerinfo for this router, and an identity key to sign
* with, encode the routerinfo as a signed server descriptor and write the
* result into <b>s</b>, using at most <b>maxlen</b> bytes. Return -1 on
* failure, and the number of bytes used on success.
* with, encode the routerinfo as a signed server descriptor and return a new
* string encoding the result, or NULL on failure.
*/
int
router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router,
char *
router_dump_router_to_string(routerinfo_t *router,
crypto_pk_t *ident_key)
{
char *onion_pkey; /* Onion key, PEM-encoded. */
char *identity_pkey; /* Identity key, PEM-encoded. */
char *onion_pkey = NULL; /* Onion key, PEM-encoded. */
char *identity_pkey = NULL; /* Identity key, PEM-encoded. */
char digest[DIGEST_LEN];
char published[ISO_TIME_LEN+1];
char fingerprint[FINGERPRINT_LEN+1];
int has_extra_info_digest;
char extra_info_digest[HEX_DIGEST_LEN+1];
size_t onion_pkeylen, identity_pkeylen;
size_t written;
int result=0;
char *family_line;
char *family_line = NULL;
char *extra_or_address = NULL;
const or_options_t *options = get_options();
smartlist_t *chunks = NULL;
char *output = NULL;
size_t output_len;
/* Make sure the identity key matches the one in the routerinfo. */
if (!crypto_pk_eq_keys(ident_key, router->identity_pkey)) {
log_warn(LD_BUG,"Tried to sign a router with a private key that didn't "
"match router's public key!");
return -1;
goto err;
}
/* record our fingerprint, so we can include it in the descriptor */
if (crypto_pk_get_fingerprint(router->identity_pkey, fingerprint, 1)<0) {
log_err(LD_BUG,"Error computing fingerprint");
return -1;
goto err;
}
/* PEM-encode the onion key */
if (crypto_pk_write_public_key_to_string(router->onion_pkey,
&onion_pkey,&onion_pkeylen)<0) {
log_warn(LD_BUG,"write onion_pkey to string failed!");
return -1;
goto err;
}
/* PEM-encode the identity key */
if (crypto_pk_write_public_key_to_string(router->identity_pkey,
&identity_pkey,&identity_pkeylen)<0) {
log_warn(LD_BUG,"write identity_pkey to string failed!");
tor_free(onion_pkey);
return -1;
goto err;
}
/* Encode the publication time. */
@ -2311,8 +2309,9 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router,
}
}
chunks = smartlist_new();
/* Generate the easy portion of the router descriptor. */
result = tor_snprintf(s, maxlen,
smartlist_add_asprintf(chunks,
"router %s %s %d 0 %d\n"
"%s"
"platform %s\n"
@ -2347,28 +2346,11 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router,
options->HidServDirectoryV2 ? "hidden-service-dir\n" : "",
options->AllowSingleHopExits ? "allow-single-hop-exits\n" : "");
tor_free(family_line);
tor_free(onion_pkey);
tor_free(identity_pkey);
tor_free(extra_or_address);
if (result < 0) {
log_warn(LD_BUG,"descriptor snprintf #1 ran out of room!");
return -1;
}
/* From now on, we use 'written' to remember the current length of 's'. */
written = result;
if (options->ContactInfo && strlen(options->ContactInfo)) {
const char *ci = options->ContactInfo;
if (strchr(ci, '\n') || strchr(ci, '\r'))
ci = escaped(ci);
result = tor_snprintf(s+written,maxlen-written, "contact %s\n", ci);
if (result<0) {
log_warn(LD_BUG,"descriptor snprintf #2 ran out of room!");
return -1;
}
written += result;
smartlist_add_asprintf(chunks, "contact %s\n", ci);
}
#ifdef CURVE25519_ENABLED
@ -2377,105 +2359,94 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router,
base64_encode(kbuf, sizeof(kbuf),
(const char *)router->onion_curve25519_pkey->public_key,
CURVE25519_PUBKEY_LEN);
result = tor_snprintf(s+written,maxlen-written, "ntor-onion-key %s",
kbuf);
if (result<0) {
log_warn(LD_BUG,"descriptor snprintf ran out of room!");
return -1;
}
written += result;
smartlist_add_asprintf(chunks, "ntor-onion-key %s", kbuf);
}
#endif
/* Write the exit policy to the end of 's'. */
if (!router->exit_policy || !smartlist_len(router->exit_policy)) {
strlcat(s+written, "reject *:*\n", maxlen-written);
written += strlen("reject *:*\n");
smartlist_add(chunks, tor_strdup("reject *:*\n"));
} else if (router->exit_policy) {
int i;
for (i = 0; i < smartlist_len(router->exit_policy); ++i) {
char pbuf[POLICY_BUF_LEN];
addr_policy_t *tmpe = smartlist_get(router->exit_policy, i);
int result;
if (tor_addr_family(&tmpe->addr) == AF_INET6)
continue; /* Don't include IPv6 parts of address policy */
result = policy_write_item(s+written, maxlen-written, tmpe, 1);
result = policy_write_item(pbuf, POLICY_BUF_LEN, tmpe, 1);
if (result < 0) {
log_warn(LD_BUG,"descriptor policy_write_item ran out of room!");
return -1;
goto err;
}
tor_assert(result == (int)strlen(s+written));
written += result;
if (written+2 > maxlen) {
log_warn(LD_BUG,"descriptor policy_write_item ran out of room (2)!");
return -1;
}
s[written++] = '\n';
smartlist_add_asprintf(chunks, "%s\n", pbuf);
}
}
if (router->ipv6_exit_policy) {
char *p6 = write_short_policy(router->ipv6_exit_policy);
if (p6 && strcmp(p6, "reject 1-65535")) {
result = tor_snprintf(s+written, maxlen-written,
smartlist_add_asprintf(chunks,
"ipv6-policy %s\n", p6);
if (result<0) {
log_warn(LD_BUG,"Descriptor printf of policy ran out of room");
tor_free(p6);
return -1;
}
written += result;
}
tor_free(p6);
}
if (written + DIROBJ_MAX_SIG_LEN > maxlen) {
/* Not enough room for signature. */
log_warn(LD_BUG,"not enough room left in descriptor for signature!");
return -1;
}
/* Sign the descriptor */
strlcpy(s+written, "router-signature\n", maxlen-written);
written += strlen(s+written);
s[written] = '\0';
if (router_get_router_hash(s, strlen(s), digest) < 0) {
return -1;
smartlist_add(chunks, tor_strdup("router-signature\n"));
output = smartlist_join_strings(chunks, "", 0, NULL);
#define MAX_DESC_SIGNATURE_LEN 4096
output_len = strlen(output) + MAX_DESC_SIGNATURE_LEN + 1;
output = tor_realloc(output, output_len);
if (router_get_router_hash(output, strlen(output), digest) < 0) {
goto err;
}
note_crypto_pk_op(SIGN_RTR);
if (router_append_dirobj_signature(s+written,maxlen-written,
if (router_append_dirobj_signature(output, output_len,
digest,DIGEST_LEN,ident_key)<0) {
log_warn(LD_BUG, "Couldn't sign router descriptor");
return -1;
goto err;
}
written += strlen(s+written);
if (written+2 > maxlen) {
log_warn(LD_BUG,"Not enough room to finish descriptor.");
return -1;
}
/* include a last '\n' */
s[written] = '\n';
s[written+1] = 0;
strlcat(output, "\n", output_len);
#ifdef DEBUG_ROUTER_DUMP_ROUTER_TO_STRING
{
char *s_dup;
const char *cp;
routerinfo_t *ri_tmp;
cp = s_dup = tor_strdup(s);
cp = s_dup = tor_strdup(output);
ri_tmp = router_parse_entry_from_string(cp, NULL, 1, 0, NULL);
if (!ri_tmp) {
log_err(LD_BUG,
"We just generated a router descriptor we can't parse.");
log_err(LD_BUG, "Descriptor was: <<%s>>", s);
return -1;
log_err(LD_BUG, "Descriptor was: <<%s>>", output);
goto err;
}
tor_free(s_dup);
routerinfo_free(ri_tmp);
}
#endif
return (int)written+1;
goto done;
err:
tor_free(output); /* sets output to NULL */
done:
if (chunks) {
SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp));
smartlist_free(chunks);
}
tor_free(family_line);
tor_free(onion_pkey);
tor_free(identity_pkey);
tor_free(extra_or_address);
return output;
}
/** Copy the primary (IPv4) OR port (IP address and TCP port) for

View File

@ -90,8 +90,8 @@ int router_is_me(const routerinfo_t *router);
int router_fingerprint_is_me(const char *fp);
int router_pick_published_address(const or_options_t *options, uint32_t *addr);
int router_rebuild_descriptor(int force);
int router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router,
crypto_pk_t *ident_key);
char *router_dump_router_to_string(routerinfo_t *router,
crypto_pk_t *ident_key);
void router_get_prim_orport(const routerinfo_t *router,
tor_addr_port_t *addr_port_out);
void router_get_pref_orport(const routerinfo_t *router,

View File

@ -73,7 +73,8 @@ test_dir_nicknames(void)
static void
test_dir_formats(void)
{
char buf[8192], buf2[8192];
char *buf = NULL;
char buf2[8192];
char platform[256];
char fingerprint[FINGERPRINT_LEN+1];
char *pk1_str = NULL, *pk2_str = NULL, *pk3_str = NULL, *cp;
@ -142,8 +143,8 @@ test_dir_formats(void)
test_assert(!crypto_pk_write_public_key_to_string(pk3 , &pk3_str,
&pk3_str_len));
memset(buf, 0, 2048);
test_assert(router_dump_router_to_string(buf, 2048, r1, pk2)>0);
buf = router_dump_router_to_string(r1, pk2);
test_assert(buf);
strlcpy(buf2, "router Magri 18.244.0.1 9000 0 9003\n"
"or-address [1:2:3:4::]:9999\n"
@ -170,8 +171,10 @@ test_dir_formats(void)
* twice */
test_streq(buf, buf2);
tor_free(buf);
test_assert(router_dump_router_to_string(buf, 2048, r1, pk2)>0);
buf = router_dump_router_to_string(r1, pk2);
test_assert(buf);
cp = buf;
rp1 = router_parse_entry_from_string((const char*)cp,NULL,1,0,NULL);
test_assert(rp1);
@ -232,6 +235,7 @@ test_dir_formats(void)
if (r2)
routerinfo_free(r2);
tor_free(buf);
tor_free(pk1_str);
tor_free(pk2_str);
tor_free(pk3_str);