[or-cvs] r12396: Parse CERT cells and act correctly when we get them. (in tor/trunk: . doc src/common src/or)
nickm at seul.org
nickm at seul.org
Tue Nov 6 18:00:07 UTC 2007
Author: nickm
Date: 2007-11-06 13:00:07 -0500 (Tue, 06 Nov 2007)
New Revision: 12396
Modified:
tor/trunk/
tor/trunk/doc/TODO
tor/trunk/src/common/crypto.c
tor/trunk/src/common/crypto.h
tor/trunk/src/common/tortls.c
tor/trunk/src/common/tortls.h
tor/trunk/src/or/command.c
tor/trunk/src/or/connection_or.c
Log:
r16455 at catbus: nickm | 2007-11-06 12:48:00 -0500
Parse CERT cells and act correctly when we get them.
Property changes on: tor/trunk
___________________________________________________________________
svk:merge ticket from /tor/trunk [r16455] on 8246c3cf-6607-4228-993b-4d95d33730f1
Modified: tor/trunk/doc/TODO
===================================================================
--- tor/trunk/doc/TODO 2007-11-06 14:21:08 UTC (rev 12395)
+++ tor/trunk/doc/TODO 2007-11-06 18:00:07 UTC (rev 12396)
@@ -34,16 +34,16 @@
o Add parse logic
o Make CERT variable.
o Make VERSIONS variable.
- - CERT cells
- - functions to parse x509 certs
- - functions to validate a single x509 cert against a TLS connection
- - functions to validate a chain of x509 certs, and extract a PK.
+ o CERT cells
+ o functions to parse x509 certs
+ o functions to validate a single x509 cert against a TLS connection
+ o functions to validate a chain of x509 certs, and extract a PK.
o function to encode x509 certs
o Parse CERT cells
o Generate CERT cells
o Keep copies of X509 certs around, not necessarily associated with
connection.
- - LINK_AUTH cells
+ . LINK_AUTH cells
o Code to generate
o Remember certificate digests from TLS
o Code to parse and check
Modified: tor/trunk/src/common/crypto.c
===================================================================
--- tor/trunk/src/common/crypto.c 2007-11-06 14:21:08 UTC (rev 12395)
+++ tor/trunk/src/common/crypto.c 2007-11-06 18:00:07 UTC (rev 12396)
@@ -246,6 +246,17 @@
return env;
}
+/** used by tortls.c: wrap the RSA from an evp_pkey in a crypto_pk_env_t.
+ * returns NULL if this isn't an RSA key. */
+crypto_pk_env_t *
+_crypto_new_pk_env_evp_pkey(EVP_PKEY *pkey)
+{
+ RSA *rsa;
+ if (!(rsa = EVP_PKEY_get1_RSA(pkey)))
+ return NULL;
+ return _crypto_new_pk_env_rsa(rsa);
+}
+
/** used by tortls.c: get an equivalent EVP_PKEY* for a crypto_pk_env_t. Iff
* private is set, include the private-key portion of the key. */
EVP_PKEY *
Modified: tor/trunk/src/common/crypto.h
===================================================================
--- tor/trunk/src/common/crypto.h 2007-11-06 14:21:08 UTC (rev 12395)
+++ tor/trunk/src/common/crypto.h 2007-11-06 18:00:07 UTC (rev 12396)
@@ -195,6 +195,7 @@
struct evp_pkey_st;
struct dh_st;
crypto_pk_env_t *_crypto_new_pk_env_rsa(struct rsa_st *rsa);
+crypto_pk_env_t *_crypto_new_pk_env_evp_pkey(struct evp_pkey_st *pkey);
struct evp_pkey_st *_crypto_pk_env_get_evp_pkey(crypto_pk_env_t *env,
int private);
struct dh_st *_crypto_dh_env_get_dh(crypto_dh_env_t *dh);
Modified: tor/trunk/src/common/tortls.c
===================================================================
--- tor/trunk/src/common/tortls.c 2007-11-06 14:21:08 UTC (rev 12395)
+++ tor/trunk/src/common/tortls.c 2007-11-06 18:00:07 UTC (rev 12396)
@@ -815,27 +815,22 @@
tor_free(s2);
}
-/** If the provided tls connection is authenticated and has a
- * certificate that is currently valid and signed, then set
- * *<b>identity_key</b> to the identity certificate's key and return
- * 0. Else, return -1 and log complaints with log-level <b>severity</b>.
- */
-int
-tor_tls_verify_v1(int severity, tor_tls_t *tls, crypto_pk_env_t **identity_key)
+/** DOCDOC helper.
+ * cert_out needs to be freed. id_cert_out doesn't. */
+static void
+try_to_extract_certs_from_tls(int severity, tor_tls_t *tls,
+ X509 **cert_out, X509 **id_cert_out)
{
X509 *cert = NULL, *id_cert = NULL;
STACK_OF(X509) *chain = NULL;
- EVP_PKEY *id_pkey = NULL;
- RSA *rsa;
- int num_in_chain;
- int r = -1, i;
+ int num_in_chain, i;
+ *cert_out = *id_cert_out = NULL;
- *identity_key = NULL;
-
if (!(cert = SSL_get_peer_certificate(tls->ssl)))
- goto done;
+ return;
+ *cert_out = cert;
if (!(chain = SSL_get_peer_cert_chain(tls->ssl)))
- goto done;
+ return;
num_in_chain = sk_X509_num(chain);
/* 1 means we're receiving (server-side), and it's just the id_cert.
* 2 means we're connecting (client-side), and it's both the link
@@ -845,18 +840,38 @@
log_fn(severity,LD_PROTOCOL,
"Unexpected number of certificates in chain (%d)",
num_in_chain);
- goto done;
+ return;
}
for (i=0; i<num_in_chain; ++i) {
id_cert = sk_X509_value(chain, i);
if (X509_cmp(id_cert, cert) != 0)
break;
}
+ *id_cert_out = id_cert;
+}
+
+/** If the provided tls connection is authenticated and has a
+ * certificate that is currently valid and signed, then set
+ * *<b>identity_key</b> to the identity certificate's key and return
+ * 0. Else, return -1 and log complaints with log-level <b>severity</b>.
+ */
+int
+tor_tls_verify_v1(int severity, tor_tls_t *tls, crypto_pk_env_t **identity_key)
+{
+ X509 *cert = NULL, *id_cert = NULL;
+ EVP_PKEY *id_pkey = NULL;
+ RSA *rsa;
+ int r = -1;
+
+ *identity_key = NULL;
+
+ try_to_extract_certs_from_tls(severity, tls, &cert, &id_cert);
+ if (!cert)
+ goto done;
if (!id_cert) {
log_fn(severity,LD_PROTOCOL,"No distinct identity certificate found");
goto done;
}
-
if (!(id_pkey = X509_get_pubkey(id_cert)) ||
X509_verify(cert, id_pkey) <= 0) {
log_fn(severity,LD_PROTOCOL,"X509_verify on cert and pkey returned <= 0");
@@ -884,6 +899,111 @@
return r;
}
+/** DOCDOC
+ *
+ * Returns 1 on "verification is done", 0 on "still need LINK_AUTH."
+ */
+int
+tor_tls_verify_certs_v2(int severity, tor_tls_t *tls,
+ const char *cert_str, size_t cert_len,
+ const char *id_cert_str, size_t id_cert_len,
+ crypto_pk_env_t **cert_key_out,
+ char *conn_cert_digest_out,
+ char *id_digest_out)
+{
+ X509 *cert = NULL, *id_cert = NULL;
+ EVP_PKEY *id_pkey = NULL, *cert_pkey = NULL;
+ int free_id_cert = 0, peer_used_tls_cert = 0;
+ int r = -1;
+
+ tor_assert(cert_key_out);
+ tor_assert(conn_cert_digest_out);
+ tor_assert(id_digest_out);
+
+ *cert_key_out = NULL;
+
+ if (cert_str && cert_len) {
+ /*XXXX020 warn on error. */
+ const unsigned char *cp = (const unsigned char*) cert_str;
+ cert = d2i_X509(NULL, &cp, cert_len);
+ }
+ if (id_cert_str && id_cert_len) {
+ /*XXXX020 warn on error. */
+ const unsigned char *cp = (const unsigned char*) id_cert_str;
+ id_cert = d2i_X509(NULL, &cp, id_cert_len);
+ if (id_cert)
+ free_id_cert = 1;
+ }
+
+ if (cert) {
+ int cmp = 0;
+ X509 *cert_tmp = SSL_get_peer_certificate(tls->ssl);
+ if (cert_tmp) {
+ peer_used_tls_cert = 1;
+ cmp = X509_cmp(cert, cert_tmp);
+ X509_free(cert_tmp);
+ }
+ if (cmp != 0) {
+ log_fn(severity, LD_PROTOCOL,
+ "Certificate in CERT cell didn't match TLS cert.");
+ goto done;
+ }
+ }
+
+ if (!cert || !id_cert) {
+ X509 *c=NULL, *id=NULL;
+ try_to_extract_certs_from_tls(severity, tls, &c, &id);
+ if (c) {
+ if (!cert)
+ cert = c;
+ else
+ X509_free(c);
+ }
+ if (id && !id_cert)
+ id_cert = id;
+ }
+ if (!id_cert || !cert)
+ goto done;
+
+ if (!(id_pkey = X509_get_pubkey(id_cert)) ||
+ X509_verify(cert, id_pkey) <= 0) {
+ log_fn(severity,LD_PROTOCOL,"X509_verify on cert and pkey returned <= 0");
+ tls_log_errors(severity,"verifying certificate");
+ goto done;
+ }
+
+ {
+ crypto_pk_env_t *i = _crypto_new_pk_env_evp_pkey(id_pkey);
+ if (!i)
+ goto done;
+ crypto_pk_get_digest(i, id_digest_out);
+ crypto_free_pk_env(i);
+ }
+ if (!(cert_pkey = X509_get_pubkey(cert)))
+ goto done;
+ if (!(*cert_key_out = _crypto_new_pk_env_evp_pkey(cert_pkey)))
+ goto done;
+
+ {
+ unsigned int len = 0;
+ X509_digest(cert, EVP_sha1(), (unsigned char*)conn_cert_digest_out, &len);
+ tor_assert(len == DIGEST_LEN);
+ }
+
+ r = peer_used_tls_cert ? 1 : 0;
+ done:
+ if (cert)
+ X509_free(cert);
+ if (id_cert && free_id_cert)
+ X509_free(id_cert);
+ if (id_pkey)
+ EVP_PKEY_free(id_pkey);
+ if (cert_pkey)
+ EVP_PKEY_free(cert_pkey);
+
+ return r;
+}
+
/** Check whether the certificate set on the connection <b>tls</b> is
* expired or not-yet-valid, give or take <b>tolerance</b>
* seconds. Return 0 for valid, -1 for failure.
Modified: tor/trunk/src/common/tortls.h
===================================================================
--- tor/trunk/src/common/tortls.h 2007-11-06 14:21:08 UTC (rev 12395)
+++ tor/trunk/src/common/tortls.h 2007-11-06 18:00:07 UTC (rev 12396)
@@ -60,6 +60,12 @@
crypto_pk_env_t *tor_tls_dup_private_key(tor_tls_t *tls);
int tor_tls_verify_v1(int severity, tor_tls_t *tls,
crypto_pk_env_t **identity);
+int tor_tls_verify_certs_v2(int severity, tor_tls_t *tls,
+ const char *cert_str, size_t cert_len,
+ const char *id_cert_str, size_t id_cert_len,
+ crypto_pk_env_t **cert_key_out,
+ char *conn_cert_digest_out,
+ char *id_digest_out);
int tor_tls_check_lifetime(tor_tls_t *tls, int tolerance);
int tor_tls_read(tor_tls_t *tls, char *cp, size_t len);
int tor_tls_write(tor_tls_t *tls, const char *cp, size_t n);
Modified: tor/trunk/src/or/command.c
===================================================================
--- tor/trunk/src/or/command.c 2007-11-06 14:21:08 UTC (rev 12395)
+++ tor/trunk/src/or/command.c 2007-11-06 18:00:07 UTC (rev 12396)
@@ -608,9 +608,10 @@
command_process_cert_cell(var_cell_t *cell, or_connection_t *conn)
{
int n_certs = 0;
- uint16_t conn_cert_len, id_cert_len;
+ uint16_t conn_cert_len = 0, id_cert_len = 0;
const char *conn_cert = NULL, *id_cert = NULL;
const char *cp, *end;
+ int authenticated = 0;
/*XXXX020 log messages*/
if (conn->_base.state != OR_CONN_STATE_OR_HANDSHAKING)
@@ -633,9 +634,11 @@
if (end-cp < len)
goto err;
if (n_certs == 0) {
- conn_cert = cp;
- conn_cert_len = len;
+ id_cert = cp;
+ id_cert_len = len;
} else if (n_certs == 1) {
+ conn_cert = id_cert;
+ conn_cert_len = id_cert_len;
id_cert = cp;
id_cert_len = len;
} else {
@@ -646,20 +649,34 @@
}
/* Now we have 0, 1, or 2 certs. */
+ if (n_certs == 0) {
+ /* The other side is unauthenticated. */
+ } else {
+ int r;
+ r = tor_tls_verify_certs_v2(LOG_PROTOCOL_WARN, conn->tls,
+ conn_cert, conn_cert_len,
+ id_cert, id_cert_len,
+ &conn->handshake_state->signing_key,
+ (conn->handshake_state->started_here ?
+ conn->handshake_state->server_cert_digest :
+ conn->handshake_state->client_cert_digest),
+ conn->handshake_state->cert_id_digest);
+ if (r < 0)
+ goto err;
+ if (r == 1)
+ authenticated = 1;
+ }
+ conn->handshake_state->received_certs = 1;
+ if (authenticated) {
+ /* XXXX020 make the connection open. */
+ }
+ if (! conn->handshake_state->signing_key)
+ goto err;
- /* Verify that identity cert has signed peer cert in SSL, or
- * peer cert in the cell. */
- /* Verify that identity cert is self-signed. */
- /* Learn ID digest. */
- /* Learn cert digests. */
- /* Remember peer cert public key. */
- /* set received_certs. */
-
- conn->handshake_state->received_certs = 1;
return;
err:
- ;
+ /*XXXX020 close the connection */;
}
#define LINK_AUTH_STRING "Tor initiator certificate verification"
@@ -732,7 +749,7 @@
/* Okay, we're authenticated. */
s->authenticated = 1;
- /* XXXX020 act on being authenticated: */
+ /* XXXX020 act on being authenticated: Open the connection. */
return;
err:
Modified: tor/trunk/src/or/connection_or.c
===================================================================
--- tor/trunk/src/or/connection_or.c 2007-11-06 14:21:08 UTC (rev 12395)
+++ tor/trunk/src/or/connection_or.c 2007-11-06 18:00:07 UTC (rev 12396)
@@ -633,8 +633,9 @@
* this guy; and note that this guy is reachable.
*/
static int
-connection_or_check_valid_handshake(or_connection_t *conn, int started_here,
- char *digest_rcvd)
+connection_or_check_valid_tls_handshake(or_connection_t *conn,
+ int started_here,
+ char *digest_rcvd_out)
{
crypto_pk_env_t *identity_rcvd=NULL;
or_options_t *options = get_options();
@@ -677,7 +678,7 @@
if (identity_rcvd) {
has_identity=1;
- crypto_pk_get_digest(identity_rcvd, digest_rcvd);
+ crypto_pk_get_digest(identity_rcvd, digest_rcvd_out);
if (crypto_pk_cmp_keys(get_identity_key(), identity_rcvd)<0) {
conn->circ_id_type = CIRC_ID_TYPE_LOWER;
@@ -686,12 +687,12 @@
}
crypto_free_pk_env(identity_rcvd);
} else {
- memset(digest_rcvd, 0, DIGEST_LEN);
+ memset(digest_rcvd_out, 0, DIGEST_LEN);
conn->circ_id_type = CIRC_ID_TYPE_NEITHER;
}
if (started_here && tor_digest_is_zero(conn->identity_digest)) {
- memcpy(conn->identity_digest, digest_rcvd, DIGEST_LEN);
+ memcpy(conn->identity_digest, digest_rcvd_out, DIGEST_LEN);
tor_free(conn->nickname);
conn->nickname = tor_malloc(HEX_DIGEST_LEN+2);
conn->nickname[0] = '$';
@@ -706,11 +707,11 @@
int as_advertised = 1;
tor_assert(has_cert);
tor_assert(has_identity);
- if (memcmp(digest_rcvd, conn->identity_digest, DIGEST_LEN)) {
+ if (memcmp(digest_rcvd_out, conn->identity_digest, DIGEST_LEN)) {
/* I was aiming for a particular digest. I didn't get it! */
char seen[HEX_DIGEST_LEN+1];
char expected[HEX_DIGEST_LEN+1];
- base16_encode(seen, sizeof(seen), digest_rcvd, DIGEST_LEN);
+ base16_encode(seen, sizeof(seen), digest_rcvd_out, DIGEST_LEN);
base16_encode(expected, sizeof(expected), conn->identity_digest,
DIGEST_LEN);
log_fn(severity, LD_OR,
@@ -728,7 +729,7 @@
* with the same address:port and a different key.
*/
dirserv_orconn_tls_done(conn->_base.address, conn->_base.port,
- digest_rcvd, as_advertised);
+ digest_rcvd_out, as_advertised);
}
if (!as_advertised)
return -1;
@@ -755,7 +756,8 @@
log_debug(LD_OR,"tls handshake done. verifying.");
/* V1 only XXXX020 */
- if (connection_or_check_valid_handshake(conn, started_here, digest_rcvd) < 0)
+ if (connection_or_check_valid_tls_handshake(conn, started_here,
+ digest_rcvd) < 0)
return -1;
if (!started_here) { /* V1 only XXXX020 */
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