On v3 link handshake, send the correct link certificate

Previously we'd send the _current_ link certificate, which would
cause a handshaking failure when the TLS context rotated.
This commit is contained in:
Nick Mathewson 2017-05-31 19:12:32 -04:00
parent ec61ae59a5
commit 50facb40bb
3 changed files with 37 additions and 12 deletions

View File

@ -2021,6 +2021,24 @@ tor_tls_get_peer_cert,(tor_tls_t *tls))
return tor_x509_cert_new(cert);
}
/** Return the cerficate we used on the connection, or NULL if somehow
* we didn't use one. */
tor_x509_cert_t *
tor_tls_get_own_cert(tor_tls_t *tls)
{
X509 *cert = SSL_get_certificate(tls->ssl);
tls_log_errors(tls, LOG_WARN, LD_HANDSHAKE,
"getting own-connection certificate");
if (!cert)
return NULL;
/* Fun inconsistency: SSL_get_peer_certificate increments the reference
* count, but SSL_get_certificate does not. */
X509 *duplicate = X509_dup(cert);
if (BUG(duplicate == NULL))
return NULL;
return tor_x509_cert_new(duplicate);
}
/** Warn that a certificate lifetime extends through a certain range. */
static void
log_cert_lifetime(int severity, const X509 *cert, const char *problem)

View File

@ -198,6 +198,7 @@ int tor_tls_is_server(tor_tls_t *tls);
void tor_tls_free(tor_tls_t *tls);
int tor_tls_peer_has_cert(tor_tls_t *tls);
MOCK_DECL(tor_x509_cert_t *,tor_tls_get_peer_cert,(tor_tls_t *tls));
tor_x509_cert_t *tor_tls_get_own_cert(tor_tls_t *tls);
int tor_tls_verify(int severity, tor_tls_t *tls, crypto_pk_t **identity);
int tor_tls_check_lifetime(int severity,
tor_tls_t *tls, int past_tolerance,

View File

@ -2137,7 +2137,9 @@ connection_or_send_netinfo,(or_connection_t *conn))
int
connection_or_send_certs_cell(or_connection_t *conn)
{
const tor_x509_cert_t *link_cert = NULL, *id_cert = NULL;
const tor_x509_cert_t *global_link_cert = NULL, *id_cert = NULL,
*using_link_cert = NULL;
tor_x509_cert_t *own_link_cert = NULL;
const uint8_t *link_encoded = NULL, *id_encoded = NULL;
size_t link_len, id_len;
var_cell_t *cell;
@ -2149,9 +2151,15 @@ connection_or_send_certs_cell(or_connection_t *conn)
if (! conn->handshake_state)
return -1;
const int conn_in_server_mode = ! conn->handshake_state->started_here;
if (tor_tls_get_my_certs(conn_in_server_mode, &link_cert, &id_cert) < 0)
if (tor_tls_get_my_certs(conn_in_server_mode,
&global_link_cert, &id_cert) < 0)
return -1;
tor_x509_cert_get_der(link_cert, &link_encoded, &link_len);
if (conn_in_server_mode) {
using_link_cert = own_link_cert = tor_tls_get_own_cert(conn->tls);
} else {
using_link_cert = global_link_cert;
}
tor_x509_cert_get_der(using_link_cert, &link_encoded, &link_len);
tor_x509_cert_get_der(id_cert, &id_encoded, &id_len);
cell_len = 1 /* 1 byte: num certs in cell */ +
@ -2179,6 +2187,7 @@ connection_or_send_certs_cell(or_connection_t *conn)
connection_or_write_var_cell_to_buf(cell, conn);
var_cell_free(cell);
tor_x509_cert_free(own_link_cert);
return 0;
}
@ -2258,10 +2267,10 @@ connection_or_compute_authenticate_cell_body(or_connection_t *conn,
memcpy(auth1_getarray_type(auth), "AUTH0001", 8);
{
const tor_x509_cert_t *id_cert=NULL, *link_cert=NULL;
const tor_x509_cert_t *id_cert=NULL;
const common_digests_t *my_digests, *their_digests;
const uint8_t *my_id, *their_id, *client_id, *server_id;
if (tor_tls_get_my_certs(server, &link_cert, &id_cert))
if (tor_tls_get_my_certs(server, NULL, &id_cert))
goto err;
my_digests = tor_x509_cert_get_id_digests(id_cert);
their_digests =
@ -2300,13 +2309,11 @@ connection_or_compute_authenticate_cell_body(or_connection_t *conn,
{
/* Digest of cert used on TLS link : 32 octets. */
const tor_x509_cert_t *cert = NULL;
tor_x509_cert_t *freecert = NULL;
tor_x509_cert_t *cert = NULL;
if (server) {
tor_tls_get_my_certs(1, &cert, NULL);
cert = tor_tls_get_own_cert(conn->tls);
} else {
freecert = tor_tls_get_peer_cert(conn->tls);
cert = freecert;
cert = tor_tls_get_peer_cert(conn->tls);
}
if (!cert) {
log_warn(LD_OR, "Unable to find cert when making AUTH1 data.");
@ -2316,8 +2323,7 @@ connection_or_compute_authenticate_cell_body(or_connection_t *conn,
memcpy(auth->scert,
tor_x509_cert_get_cert_digests(cert)->d[DIGEST_SHA256], 32);
if (freecert)
tor_x509_cert_free(freecert);
tor_x509_cert_free(cert);
}
/* HMAC of clientrandom and serverrandom using master key : 32 octets */