commit a9be768959c189846178723d5fe44d3b59b0d983
Author: Nick Mathewson <nickm(a)torproject.org>
Date: Wed May 31 18:33:38 2017 -0400
Bugfix: Regenerate more certificates when appropriate
Previously we could sometimes change our signing key, but not
regenerate the certificates (signing->link and signing->auth) that
were signed with it. Also, we would regularly replace our TLS x.509
link certificate (by rotating our TLS context) but not replace our
signing->link ed25519 certificate. In both cases, the resulting
inconsistency would make other relays reject our link handshakes.
Fixes two cases of bug 22460; bugfix on 0.3.0.1-alpha.
---
changes/bug22460_case1 | 10 ++++++++++
src/or/main.c | 17 ++++++++++++-----
src/or/router.c | 5 +++--
src/or/routerkeys.c | 37 +++++++++++++++++++++++++++++++------
src/or/routerkeys.h | 2 +-
src/test/test_routerkeys.c | 20 ++++++++++----------
src/test/test_shared_random.c | 4 ++--
7 files changed, 69 insertions(+), 26 deletions(-)
diff --git a/changes/bug22460_case1 b/changes/bug22460_case1
new file mode 100644
index 0000000..9aef46b
--- /dev/null
+++ b/changes/bug22460_case1
@@ -0,0 +1,10 @@
+ o Major bugfixes (relays, key management):
+ - Regenerate link and authentication certificates whenever the key that
+ signs them changes; also, regenerate link certificates whenever the
+ signed key changes. Previously, these processes were only weakly
+ coupled, and we relays could (for minutes to hours) wind up with an
+ inconsistent set of keys and certificates, which other relays
+ would not accept. Fixes two cases of bug 22460; bugfix on
+ 0.3.0.1-alpha.
+
+
diff --git a/src/or/main.c b/src/or/main.c
index bc7b3db..3139381 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -1506,8 +1506,9 @@ check_ed_keys_callback(time_t now, const or_options_t *options)
{
if (server_mode(options)) {
if (should_make_new_ed_keys(options, now)) {
- if (load_ed_keys(options, now) < 0 ||
- generate_ed_link_cert(options, now)) {
+ int new_signing_key = load_ed_keys(options, now);
+ if (new_signing_key < 0 ||
+ generate_ed_link_cert(options, now, new_signing_key > 0)) {
log_err(LD_OR, "Unable to update Ed25519 keys! Exiting.");
tor_cleanup();
exit(0);
@@ -1559,6 +1560,11 @@ rotate_x509_certificate_callback(time_t now, const or_options_t *options)
log_err(LD_BUG, "Error reinitializing TLS context");
tor_assert_unreached();
}
+ if (generate_ed_link_cert(options, now, 1)) {
+ log_err(LD_OR, "Unable to update Ed25519->TLS link certificate for "
+ "new TLS context.");
+ tor_assert_unreached();
+ }
/* We also make sure to rotate the TLS connections themselves if they've
* been up for too long -- but that's done via is_bad_for_new_circs in
@@ -2298,8 +2304,9 @@ do_hup(void)
/* Maybe we've been given a new ed25519 key or certificate?
*/
time_t now = approx_time();
- if (load_ed_keys(options, now) < 0 ||
- generate_ed_link_cert(options, now)) {
+ int new_signing_key = load_ed_keys(options, now);
+ if (new_signing_key < 0 ||
+ generate_ed_link_cert(options, now, new_signing_key > 0)) {
log_warn(LD_OR, "Problem reloading Ed25519 keys; still using old keys.");
}
@@ -3627,7 +3634,7 @@ tor_main(int argc, char *argv[])
result = do_main_loop();
break;
case CMD_KEYGEN:
- result = load_ed_keys(get_options(), time(NULL));
+ result = load_ed_keys(get_options(), time(NULL)) < 0;
break;
case CMD_LIST_FINGERPRINT:
result = do_list_fingerprint();
diff --git a/src/or/router.c b/src/or/router.c
index e4fa72a..f6b03cd 100644
--- a/src/or/router.c
+++ b/src/or/router.c
@@ -906,7 +906,8 @@ init_keys(void)
}
/* 1d. Load all ed25519 keys */
- if (load_ed_keys(options,now) < 0)
+ const int new_signing_key = load_ed_keys(options,now);
+ if (new_signing_key < 0)
return -1;
/* 2. Read onion key. Make it if none is found. */
@@ -976,7 +977,7 @@ init_keys(void)
/* 3b. Get an ed25519 link certificate. Note that we need to do this
* after we set up the TLS context */
- if (generate_ed_link_cert(options, now) < 0) {
+ if (generate_ed_link_cert(options, now, new_signing_key > 0) < 0) {
log_err(LD_GENERAL,"Couldn't make link cert");
return -1;
}
diff --git a/src/or/routerkeys.c b/src/or/routerkeys.c
index 6259e3f..1f0f82a 100644
--- a/src/or/routerkeys.c
+++ b/src/or/routerkeys.c
@@ -672,6 +672,9 @@ static size_t rsa_ed_crosscert_len = 0;
/**
* Running as a server: load, reload, or refresh our ed25519 keys and
* certificates, creating and saving new ones as needed.
+ *
+ * Return -1 on failure; 0 on success if the signing key was not replaced;
+ * and 1 on success if the signing key was replaced.
*/
int
load_ed_keys(const or_options_t *options, time_t now)
@@ -684,6 +687,7 @@ load_ed_keys(const or_options_t *options, time_t now)
const tor_cert_t *check_signing_cert = NULL;
tor_cert_t *sign_cert = NULL;
tor_cert_t *auth_cert = NULL;
+ int signing_key_changed = 0;
#define FAIL(msg) do { \
log_warn(LD_OR, (msg)); \
@@ -719,7 +723,23 @@ load_ed_keys(const or_options_t *options, time_t now)
use_signing = sign;
}
+ if (use_signing) {
+ /* We loaded a signing key with its certificate. */
+ if (! master_signing_key) {
+ /* We didn't know one before! */
+ signing_key_changed = 1;
+ } else if (! ed25519_pubkey_eq(&use_signing->pubkey,
+ &master_signing_key->pubkey) ||
+ ! tor_memeq(use_signing->seckey.seckey,
+ master_signing_key->seckey.seckey,
+ ED25519_SECKEY_LEN)) {
+ /* We loaded a different signing key than the one we knew before. */
+ signing_key_changed = 1;
+ }
+ }
+
if (!use_signing && master_signing_key) {
+ /* We couldn't load a signing key, but we already had one loaded */
check_signing_cert = signing_key_cert;
use_signing = master_signing_key;
}
@@ -879,6 +899,7 @@ load_ed_keys(const or_options_t *options, time_t now)
if (!sign)
FAIL("Missing signing key");
use_signing = sign;
+ signing_key_changed = 1;
tor_assert(sign_cert->signing_key_included);
tor_assert(ed25519_pubkey_eq(&sign_cert->signing_key, &id->pubkey));
@@ -910,6 +931,7 @@ load_ed_keys(const or_options_t *options, time_t now)
}
if (!current_auth_key ||
+ signing_key_changed ||
EXPIRES_SOON(auth_key_cert, options->TestingAuthKeySlop)) {
auth = ed_key_new(use_signing, INIT_ED_KEY_NEEDCERT,
now,
@@ -937,7 +959,7 @@ load_ed_keys(const or_options_t *options, time_t now)
SET_CERT(auth_key_cert, auth_cert);
}
- return 0;
+ return signing_key_changed;
err:
ed25519_keypair_free(id);
ed25519_keypair_free(sign);
@@ -951,16 +973,18 @@ load_ed_keys(const or_options_t *options, time_t now)
* Retrieve our currently-in-use Ed25519 link certificate and id certificate,
* and, if they would expire soon (based on the time <b>now</b>, generate new
* certificates (without embedding the public part of the signing key inside).
+ * If <b>force</b> is true, always generate a new certificate.
*
- * The signed_key from the expiring certificate will be used to sign the new
- * key within newly generated X509 certificate.
+ * The signed_key from the current id->signing certificate will be used to
+ * sign the new key within newly generated X509 certificate.
*
* Returns -1 upon error. Otherwise, returns 0 upon success (either when the
* current certificate is still valid, or when a new certificate was
* successfully generated).
*/
int
-generate_ed_link_cert(const or_options_t *options, time_t now)
+generate_ed_link_cert(const or_options_t *options, time_t now,
+ int force)
{
const tor_x509_cert_t *link_ = NULL, *id = NULL;
tor_cert_t *link_cert = NULL;
@@ -972,7 +996,8 @@ generate_ed_link_cert(const or_options_t *options, time_t now)
const common_digests_t *digests = tor_x509_cert_get_cert_digests(link_);
- if (link_cert_cert &&
+ if (force == 0 &&
+ link_cert_cert &&
! EXPIRES_SOON(link_cert_cert, options->TestingLinkKeySlop) &&
fast_memeq(digests->d[DIGEST_SHA256], link_cert_cert->signed_key.pubkey,
DIGEST256_LEN)) {
@@ -1073,7 +1098,7 @@ init_mock_ed_keys(const crypto_pk_t *rsa_identity_key)
MAKECERT(auth_key_cert,
master_signing_key, current_auth_key, CERT_TYPE_SIGNING_AUTH, 0);
- if (generate_ed_link_cert(get_options(), time(NULL)) < 0) {
+ if (generate_ed_link_cert(get_options(), time(NULL), 0) < 0) {
log_warn(LD_BUG, "Couldn't make link certificate");
goto err;
}
diff --git a/src/or/routerkeys.h b/src/or/routerkeys.h
index d2027f4..845abb4 100644
--- a/src/or/routerkeys.h
+++ b/src/or/routerkeys.h
@@ -66,7 +66,7 @@ MOCK_DECL(int, check_tap_onion_key_crosscert,(const uint8_t *crosscert,
int load_ed_keys(const or_options_t *options, time_t now);
int should_make_new_ed_keys(const or_options_t *options, const time_t now);
-int generate_ed_link_cert(const or_options_t *options, time_t now);
+int generate_ed_link_cert(const or_options_t *options, time_t now, int force);
int read_encrypted_secret_key(ed25519_secret_key_t *out,
const char *fname);
diff --git a/src/test/test_routerkeys.c b/src/test/test_routerkeys.c
index 64692d2..1305926 100644
--- a/src/test/test_routerkeys.c
+++ b/src/test/test_routerkeys.c
@@ -450,8 +450,8 @@ test_routerkeys_ed_keys_init_all(void *arg)
options->DataDirectory = dir;
- tt_int_op(0, ==, load_ed_keys(options, now));
- tt_int_op(0, ==, generate_ed_link_cert(options, now));
+ tt_int_op(1, ==, load_ed_keys(options, now));
+ tt_int_op(0, ==, generate_ed_link_cert(options, now, 0));
tt_assert(get_master_identity_key());
tt_assert(get_master_identity_key());
tt_assert(get_master_signing_keypair());
@@ -466,7 +466,7 @@ test_routerkeys_ed_keys_init_all(void *arg)
/* Call load_ed_keys again, but nothing has changed. */
tt_int_op(0, ==, load_ed_keys(options, now));
- tt_int_op(0, ==, generate_ed_link_cert(options, now));
+ tt_int_op(0, ==, generate_ed_link_cert(options, now, 0));
tt_mem_op(&id, ==, get_master_identity_key(), sizeof(id));
tt_mem_op(&sign, ==, get_master_signing_keypair(), sizeof(sign));
tt_mem_op(&auth, ==, get_current_auth_keypair(), sizeof(auth));
@@ -474,8 +474,8 @@ test_routerkeys_ed_keys_init_all(void *arg)
/* Force a reload: we make new link/auth keys. */
routerkeys_free_all();
- tt_int_op(0, ==, load_ed_keys(options, now));
- tt_int_op(0, ==, generate_ed_link_cert(options, now));
+ tt_int_op(1, ==, load_ed_keys(options, now));
+ tt_int_op(0, ==, generate_ed_link_cert(options, now, 0));
tt_mem_op(&id, ==, get_master_identity_key(), sizeof(id));
tt_mem_op(&sign, ==, get_master_signing_keypair(), sizeof(sign));
tt_assert(tor_cert_eq(link_cert, get_current_link_cert_cert()));
@@ -489,7 +489,7 @@ test_routerkeys_ed_keys_init_all(void *arg)
/* Force a link/auth-key regeneration by advancing time. */
tt_int_op(0, ==, load_ed_keys(options, now+3*86400));
- tt_int_op(0, ==, generate_ed_link_cert(options, now+3*86400));
+ tt_int_op(0, ==, generate_ed_link_cert(options, now+3*86400, 0));
tt_mem_op(&id, ==, get_master_identity_key(), sizeof(id));
tt_mem_op(&sign, ==, get_master_signing_keypair(), sizeof(sign));
tt_assert(! tor_cert_eq(link_cert, get_current_link_cert_cert()));
@@ -502,8 +502,8 @@ test_routerkeys_ed_keys_init_all(void *arg)
memcpy(&auth, get_current_auth_keypair(), sizeof(auth));
/* Force a signing-key regeneration by advancing time. */
- tt_int_op(0, ==, load_ed_keys(options, now+100*86400));
- tt_int_op(0, ==, generate_ed_link_cert(options, now+100*86400));
+ tt_int_op(1, ==, load_ed_keys(options, now+100*86400));
+ tt_int_op(0, ==, generate_ed_link_cert(options, now+100*86400, 0));
tt_mem_op(&id, ==, get_master_identity_key(), sizeof(id));
tt_mem_op(&sign, !=, get_master_signing_keypair(), sizeof(sign));
tt_assert(! tor_cert_eq(link_cert, get_current_link_cert_cert()));
@@ -520,8 +520,8 @@ test_routerkeys_ed_keys_init_all(void *arg)
routerkeys_free_all();
unlink(get_fname("test_ed_keys_init_all/keys/"
"ed25519_master_id_secret_key"));
- tt_int_op(0, ==, load_ed_keys(options, now));
- tt_int_op(0, ==, generate_ed_link_cert(options, now));
+ tt_int_op(1, ==, load_ed_keys(options, now));
+ tt_int_op(0, ==, generate_ed_link_cert(options, now, 0));
tt_mem_op(&id, ==, get_master_identity_key(), sizeof(id));
tt_mem_op(&sign, ==, get_master_signing_keypair(), sizeof(sign));
tt_assert(! tor_cert_eq(link_cert, get_current_link_cert_cert()));
diff --git a/src/test/test_shared_random.c b/src/test/test_shared_random.c
index d511f16..026a0f3 100644
--- a/src/test/test_shared_random.c
+++ b/src/test/test_shared_random.c
@@ -48,7 +48,7 @@ init_authority_state(void)
mock_cert = authority_cert_parse_from_string(AUTHORITY_CERT_1, NULL);
tt_assert(mock_cert);
options->AuthoritativeDir = 1;
- tt_int_op(0, ==, load_ed_keys(options, time(NULL)));
+ tt_int_op(load_ed_keys(options, time(NULL)), OP_GE, 0);
sr_state_init(0, 0);
/* It's possible a commit has been generated in our state depending on
* the phase we are currently in which uses "now" as the starting
@@ -286,7 +286,7 @@ test_sr_commit(void *arg)
tt_assert(auth_cert);
options->AuthoritativeDir = 1;
- tt_int_op(0, ==, load_ed_keys(options, now));
+ tt_int_op(load_ed_keys(options, time(NULL)), OP_GE, 0);
}
/* Generate our commit object and validate it has the appropriate field