* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
- *
+ *
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
* USA
*
- * $Id: gnutls.c 25793 2008-07-29 14:47:48Z androsyn $
+ * $Id: gnutls.c 26296 2008-12-13 03:36:00Z androsyn $
*/
#include <libratbox_config.h>
#ifdef HAVE_GNUTLS
#include <gnutls/gnutls.h>
-#include <gcrypt.h>
-
-static gnutls_certificate_credentials x509;
-static gnutls_dh_params dh_params;
-
-
+#include <gnutls/x509.h>
+
+#if (GNUTLS_VERSION_MAJOR < 3)
+# include <gcrypt.h>
+#else
+# include <gnutls/crypto.h>
+#endif
+
+static gnutls_certificate_credentials_t x509;
+static gnutls_dh_params_t dh_params;
+static gnutls_priority_t default_priority;
+
+/* These are all used for getting GnuTLS to supply a client cert. */
+#define MAX_CERTS 6
+static unsigned int x509_cert_count;
+static gnutls_x509_crt_t x509_cert[MAX_CERTS];
+static gnutls_x509_privkey_t x509_key;
+#if GNUTLS_VERSION_MAJOR < 3
+static int cert_callback(gnutls_session_t session, const gnutls_datum_t *req_ca_rdn, int nreqs,
+ const gnutls_pk_algorithm_t *sign_algos, int sign_algos_len, gnutls_retr_st *st);
+#else
+static int cert_callback(gnutls_session_t session, const gnutls_datum_t *req_ca_rdn, int nreqs,
+ const gnutls_pk_algorithm_t *sign_algos, int sign_algos_len, gnutls_retr2_st *st);
+#endif
#define SSL_P(x) *((gnutls_session_t *)F->ssl)
void
-rb_ssl_shutdown(rb_fde_t * F)
+rb_ssl_shutdown(rb_fde_t *F)
{
int i;
if(F == NULL || F->ssl == NULL)
return;
- for (i = 0; i < 4; i++)
+ for(i = 0; i < 4; i++)
{
if(gnutls_bye(SSL_P(F), GNUTLS_SHUT_RDWR) == GNUTLS_E_SUCCESS)
break;
}
static void
-rb_ssl_timeout(rb_fde_t * F, void *notused)
+rb_ssl_timeout(rb_fde_t *F, void *notused)
{
lrb_assert(F->accept != NULL);
F->accept->callback(F, RB_ERR_TIMEOUT, NULL, 0, F->accept->data);
}
-static int do_ssl_handshake(rb_fde_t *F, PF *callback)
+static int
+do_ssl_handshake(rb_fde_t *F, PF * callback, void *data)
{
int ret;
- int flags;
+ int flags;
ret = gnutls_handshake(SSL_P(F));
if(ret < 0)
flags = RB_SELECT_READ;
else
flags = RB_SELECT_WRITE;
- rb_setselect(F, flags, callback, NULL);
+ rb_setselect(F, flags, callback, data);
return 0;
}
F->ssl_errno = ret;
return -1;
- }
- return 1; /* handshake is finished..go about life */
+ }
+ return 1; /* handshake is finished..go about life */
}
static void
-rb_ssl_tryaccept(rb_fde_t * F, void *data)
+rb_ssl_tryaccept(rb_fde_t *F, void *data)
{
int ret;
struct acceptdata *ad;
lrb_assert(F->accept != NULL);
- ret = do_ssl_handshake(F, rb_ssl_tryaccept);
-
- switch(ret)
- {
- case -1:
- F->accept->callback(F, RB_ERROR_SSL, NULL, 0, F->accept->data);
- break;
- case 0:
- /* do_ssl_handshake does the rb_setselect stuff */
- return;
- default:
- break;
-
-
- }
- rb_settimeout(F, 0, NULL, NULL);
- rb_setselect(F, RB_SELECT_READ | RB_SELECT_WRITE, NULL, NULL);
-
+ ret = do_ssl_handshake(F, rb_ssl_tryaccept, NULL);
+
+ /* do_ssl_handshake does the rb_setselect */
+ if(ret == 0)
+ return;
+
ad = F->accept;
F->accept = NULL;
- ad->callback(F, RB_OK, (struct sockaddr *) &ad->S, ad->addrlen,
- ad->data);
- rb_free(ad);
+ rb_settimeout(F, 0, NULL, NULL);
+ rb_setselect(F, RB_SELECT_READ | RB_SELECT_WRITE, NULL, NULL);
+ if(ret > 0)
+ ad->callback(F, RB_OK, (struct sockaddr *)&ad->S, ad->addrlen, ad->data);
+ else
+ ad->callback(F, RB_ERROR_SSL, NULL, 0, ad->data);
+
+ rb_free(ad);
}
void
-rb_ssl_start_accepted(rb_fde_t * new_F, ACCB * cb, void *data, int timeout)
+rb_ssl_start_accepted(rb_fde_t *new_F, ACCB * cb, void *data, int timeout)
{
gnutls_session_t *ssl;
new_F->type |= RB_FD_SSL;
ssl = new_F->ssl = rb_malloc(sizeof(gnutls_session_t));
new_F->accept = rb_malloc(sizeof(struct acceptdata));
-
+
new_F->accept->callback = cb;
new_F->accept->data = data;
rb_settimeout(new_F, timeout, rb_ssl_timeout, NULL);
new_F->accept->addrlen = 0;
- gnutls_init(ssl, GNUTLS_SERVER);
+ gnutls_init(ssl, GNUTLS_SERVER);
gnutls_set_default_priority(*ssl);
gnutls_credentials_set(*ssl, GNUTLS_CRD_CERTIFICATE, x509);
gnutls_dh_set_prime_bits(*ssl, 1024);
gnutls_transport_set_ptr(*ssl, (gnutls_transport_ptr_t) (long int)new_F->fd);
- if(do_ssl_handshake(new_F, rb_ssl_tryaccept))
+ gnutls_certificate_server_set_request(*ssl, GNUTLS_CERT_REQUEST);
+ gnutls_priority_set(*ssl, default_priority);
+
+ if(do_ssl_handshake(new_F, rb_ssl_tryaccept, NULL))
{
struct acceptdata *ad = new_F->accept;
new_F->accept = NULL;
- ad->callback(new_F, RB_OK, (struct sockaddr *) &ad->S, ad->addrlen, ad->data);
- rb_free(ad);
+ ad->callback(new_F, RB_OK, (struct sockaddr *)&ad->S, ad->addrlen, ad->data);
+ rb_free(ad);
}
}
void
-rb_ssl_accept_setup(rb_fde_t * F, rb_fde_t *new_F, struct sockaddr *st, int addrlen)
+rb_ssl_accept_setup(rb_fde_t *F, rb_fde_t *new_F, struct sockaddr *st, int addrlen)
{
new_F->type |= RB_FD_SSL;
new_F->ssl = rb_malloc(sizeof(gnutls_session_t));
memcpy(&new_F->accept->S, st, addrlen);
new_F->accept->addrlen = addrlen;
- gnutls_init((gnutls_session_t *)new_F->ssl, GNUTLS_SERVER);
+ gnutls_init((gnutls_session_t *) new_F->ssl, GNUTLS_SERVER);
gnutls_set_default_priority(SSL_P(new_F));
gnutls_credentials_set(SSL_P(new_F), GNUTLS_CRD_CERTIFICATE, x509);
gnutls_dh_set_prime_bits(SSL_P(new_F), 1024);
gnutls_transport_set_ptr(SSL_P(new_F), (gnutls_transport_ptr_t) (long int)rb_get_fd(new_F));
- if(do_ssl_handshake(F, rb_ssl_tryaccept))
+ gnutls_certificate_server_set_request(SSL_P(new_F), GNUTLS_CERT_REQUEST);
+ gnutls_priority_set(SSL_P(F), default_priority);
+
+ if(do_ssl_handshake(F, rb_ssl_tryaccept, NULL))
{
struct acceptdata *ad = F->accept;
F->accept = NULL;
- ad->callback(F, RB_OK, (struct sockaddr *) &ad->S, ad->addrlen, ad->data);
- rb_free(ad);
+ ad->callback(F, RB_OK, (struct sockaddr *)&ad->S, ad->addrlen, ad->data);
+ rb_free(ad);
}
}
static ssize_t
-rb_ssl_read_or_write(int r_or_w, rb_fde_t * F, void *rbuf, const void *wbuf, size_t count)
+rb_ssl_read_or_write(int r_or_w, rb_fde_t *F, void *rbuf, const void *wbuf, size_t count)
{
ssize_t ret;
gnutls_session_t *ssl = F->ssl;
if(ret < 0)
{
- switch(ret)
+ switch (ret)
{
case GNUTLS_E_AGAIN:
case GNUTLS_E_INTERRUPTED:
}
ssize_t
-rb_ssl_read(rb_fde_t * F, void *buf, size_t count)
+rb_ssl_read(rb_fde_t *F, void *buf, size_t count)
{
return rb_ssl_read_or_write(0, F, buf, NULL, count);
}
ssize_t
-rb_ssl_write(rb_fde_t * F, const void *buf, size_t count)
+rb_ssl_write(rb_fde_t *F, const void *buf, size_t count)
{
return rb_ssl_read_or_write(1, F, NULL, buf, count);
}
+#if (GNUTLS_VERSION_MAJOR < 3)
static void
rb_gcry_random_seed(void *unused)
{
gcry_fast_random_poll();
}
+#endif
int
rb_init_ssl(void)
{
gnutls_global_init();
-
+
if(gnutls_certificate_allocate_credentials(&x509) != GNUTLS_E_SUCCESS)
{
rb_lib_log("rb_init_ssl: Unable to allocate SSL/TLS certificate credentials");
return 0;
}
+
+#if GNUTLS_VERSION_MAJOR < 3
+ gnutls_certificate_client_set_retrieve_function(x509, cert_callback);
+#else
+ gnutls_certificate_set_retrieve_function(x509, cert_callback);
+#endif
+
+#if (GNUTLS_VERSION_MAJOR < 3)
rb_event_addish("rb_gcry_random_seed", rb_gcry_random_seed, NULL, 300);
+#endif
+
return 1;
}
+/* We only have one certificate to authenticate with, as both client and server. Unfortunately,
+ * GnuTLS tries to be clever, and as client, will attempt to use a certificate that the server
+ * will trust. We usually use self-signed certs, though, so the result of this search is always
+ * nothing. Therefore, it uses no certificate to authenticate as a client. This is undesirable
+ * as it breaks fingerprint auth. Thus, we use this callback to force GnuTLS to always
+ * authenticate with our certificate at all times.
+ */
+#if GNUTLS_VERSION_MAJOR < 3
+static int
+cert_callback(gnutls_session_t session, const gnutls_datum_t *req_ca_rdn, int nreqs,
+ const gnutls_pk_algorithm_t *sign_algos, int sign_algos_len, gnutls_retr_st *st)
+#else
+static int
+cert_callback(gnutls_session_t session, const gnutls_datum_t *req_ca_rdn, int nreqs,
+ const gnutls_pk_algorithm_t *sign_algos, int sign_algos_len, gnutls_retr2_st *st)
+#endif
+{
+ /* XXX - ugly hack. Tell GnuTLS to use the first (only) certificate we have for auth. */
+#if (GNUTLS_VERSION_MAJOR < 3)
+ st->type = GNUTLS_CRT_X509;
+#else
+ st->cert_type = GNUTLS_CRT_X509;
+ st->key_type = GNUTLS_PRIVKEY_X509;
+#endif
+ st->ncerts = x509_cert_count;
+ st->cert.x509 = x509_cert;
+ st->key.x509 = x509_key;
+ st->deinit_all = 0;
+
+ return 0;
+}
+
static void
-rb_free_datum_t(gnutls_datum_t *d)
+rb_free_datum_t(gnutls_datum_t * d)
{
rb_free(d->data);
rb_free(d);
datum = rb_malloc(sizeof(gnutls_datum_t));
- if(fileinfo.st_size > 131072) /* deal with retards */
+ if(fileinfo.st_size > 131072) /* deal with retards */
datum->size = 131072;
else
- datum->size = fileinfo.st_size;
-
+ datum->size = fileinfo.st_size;
+
datum->data = rb_malloc(datum->size + 1);
fread(datum->data, datum->size, 1, f);
fclose(f);
- return datum;
+ return datum;
}
int
-rb_setup_ssl_server(const char *cert, const char *keyfile, const char *dhfile)
+rb_setup_ssl_server(const char *cert, const char *keyfile, const char *dhfile, const char *cipher_list)
{
int ret;
+ const char *err;
gnutls_datum_t *d_cert, *d_key;
if(cert == NULL)
{
rb_lib_log("rb_setup_ssl_server: Error loading key: %s", strerror(errno));
return 0;
}
-
-
- if((ret = gnutls_certificate_set_x509_key_mem(x509, d_cert, d_key, GNUTLS_X509_FMT_PEM)) != GNUTLS_E_SUCCESS)
+
+ /* In addition to creating the certificate set, we also need to store our cert elsewhere
+ * so we can force GnuTLS to identify with it when acting as a client.
+ */
+ gnutls_x509_privkey_init(&x509_key);
+ if ((ret = gnutls_x509_privkey_import(x509_key, d_key, GNUTLS_X509_FMT_PEM)) != GNUTLS_E_SUCCESS)
{
- rb_lib_log("rb_setup_ssl_server: Error loading certificate or key file: %s", gnutls_strerror(ret));
+ rb_lib_log("rb_setup_ssl_server: Error loading key file: %s", gnutls_strerror(ret));
return 0;
}
+
+ x509_cert_count = MAX_CERTS;
+ if ((ret = gnutls_x509_crt_list_import(x509_cert, &x509_cert_count, d_cert, GNUTLS_X509_FMT_PEM,
+ GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED)) < 0)
+ {
+ rb_lib_log("rb_setup_ssl_server: Error loading certificate: %s", gnutls_strerror(ret));
+ return 0;
+ }
+ x509_cert_count = ret;
+
+ if((ret =
+ gnutls_certificate_set_x509_key_mem(x509, d_cert, d_key,
+ GNUTLS_X509_FMT_PEM)) != GNUTLS_E_SUCCESS)
+ {
+ rb_lib_log("rb_setup_ssl_server: Error loading certificate or key file: %s",
+ gnutls_strerror(ret));
+ return 0;
+ }
+
rb_free_datum_t(d_cert);
rb_free_datum_t(d_key);
-
+
if(dhfile != NULL)
{
if(gnutls_dh_params_init(&dh_params) == GNUTLS_E_SUCCESS)
data = rb_load_file_into_datum_t(dhfile);
if(data != NULL)
{
- xret = gnutls_dh_params_import_pkcs3(dh_params, data, GNUTLS_X509_FMT_PEM);
+ xret = gnutls_dh_params_import_pkcs3(dh_params, data,
+ GNUTLS_X509_FMT_PEM);
if(xret < 0)
- rb_lib_log("rb_setup_ssl_server: Error parsing DH file: %s\n", gnutls_strerror(xret));
+ rb_lib_log
+ ("rb_setup_ssl_server: Error parsing DH file: %s\n",
+ gnutls_strerror(xret));
rb_free_datum_t(data);
}
gnutls_certificate_set_dh_params(x509, dh_params);
- } else
+ }
+ else
rb_lib_log("rb_setup_ssl_server: Unable to setup DH parameters");
}
+
+ ret = gnutls_priority_init(&default_priority, cipher_list, &err);
+ if (ret < 0)
+ {
+ rb_lib_log("rb_setup_ssl_server: syntax error (using defaults instead) in ssl cipher list at: %s", err);
+ gnutls_priority_init(&default_priority, NULL, &err);
+ return 1;
+ }
+
return 1;
}
int
-rb_ssl_listen(rb_fde_t * F, int backlog)
+rb_ssl_listen(rb_fde_t *F, int backlog, int defer_accept)
{
+ int result;
+
+ result = rb_listen(F, backlog, defer_accept);
F->type = RB_FD_SOCKET | RB_FD_LISTEN | RB_FD_SSL;
- return listen(F->fd, backlog);
+
+ return result;
}
struct ssl_connect
};
static void
-rb_ssl_connect_realcb(rb_fde_t * F, int status, struct ssl_connect *sconn)
+rb_ssl_connect_realcb(rb_fde_t *F, int status, struct ssl_connect *sconn)
{
F->connect->callback = sconn->callback;
F->connect->data = sconn->data;
}
static void
-rb_ssl_tryconn_timeout_cb(rb_fde_t * F, void *data)
+rb_ssl_tryconn_timeout_cb(rb_fde_t *F, void *data)
{
rb_ssl_connect_realcb(F, RB_ERR_TIMEOUT, data);
}
static void
-rb_ssl_tryconn_cb(rb_fde_t * F, void *data)
+rb_ssl_tryconn_cb(rb_fde_t *F, void *data)
{
struct ssl_connect *sconn = data;
int ret;
- ret = do_ssl_handshake(F, rb_ssl_tryconn_cb);
-
- switch(ret)
- {
- case -1:
- rb_ssl_connect_realcb(F, RB_ERROR_SSL, sconn);
- break;
- case 0:
- /* do_ssl_handshake does the rb_setselect stuff */
- return;
- default:
- break;
-
-
- }
+ ret = do_ssl_handshake(F, rb_ssl_tryconn_cb, (void *)sconn);
+
+ switch (ret)
+ {
+ case -1:
+ rb_ssl_connect_realcb(F, RB_ERROR_SSL, sconn);
+ break;
+ case 0:
+ /* do_ssl_handshake does the rb_setselect stuff */
+ return;
+ default:
+ break;
+
+
+ }
rb_ssl_connect_realcb(F, RB_OK, sconn);
}
static void
-rb_ssl_tryconn(rb_fde_t * F, int status, void *data)
+rb_ssl_tryconn(rb_fde_t *F, int status, void *data)
{
struct ssl_connect *sconn = data;
if(status != RB_OK)
F->type |= RB_FD_SSL;
-
+
rb_settimeout(F, sconn->timeout, rb_ssl_tryconn_timeout_cb, sconn);
F->ssl = rb_malloc(sizeof(gnutls_session_t));
- gnutls_init(F->ssl, GNUTLS_CLIENT);
- gnutls_set_default_priority(SSL_P(F));
+ gnutls_init(F->ssl, GNUTLS_CLIENT);
+ gnutls_set_default_priority(SSL_P(F));
+ gnutls_credentials_set(SSL_P(F), GNUTLS_CRD_CERTIFICATE, x509);
gnutls_dh_set_prime_bits(SSL_P(F), 1024);
gnutls_transport_set_ptr(SSL_P(F), (gnutls_transport_ptr_t) (long int)F->fd);
+ gnutls_priority_set(SSL_P(F), default_priority);
- if(do_ssl_handshake(F, rb_ssl_tryconn_cb))
- {
- rb_ssl_connect_realcb(F, RB_OK, sconn);
- }
+ do_ssl_handshake(F, rb_ssl_tryconn_cb, (void *)sconn);
}
void
-rb_connect_tcp_ssl(rb_fde_t * F, struct sockaddr *dest,
+rb_connect_tcp_ssl(rb_fde_t *F, struct sockaddr *dest,
struct sockaddr *clocal, int socklen, CNCB * callback, void *data, int timeout)
{
struct ssl_connect *sconn;
}
void
-rb_ssl_start_connected(rb_fde_t * F, CNCB * callback, void *data, int timeout)
+rb_ssl_start_connected(rb_fde_t *F, CNCB * callback, void *data, int timeout)
{
struct ssl_connect *sconn;
if(F == NULL)
F->connect->data = data;
F->type |= RB_FD_SSL;
F->ssl = rb_malloc(sizeof(gnutls_session_t));
-
- gnutls_init(F->ssl, GNUTLS_CLIENT);
- gnutls_set_default_priority(SSL_P(F));
+
+ gnutls_init(F->ssl, GNUTLS_CLIENT);
+ gnutls_set_default_priority(SSL_P(F));
+ gnutls_credentials_set(SSL_P(F), GNUTLS_CRD_CERTIFICATE, x509);
gnutls_dh_set_prime_bits(SSL_P(F), 1024);
gnutls_transport_set_ptr(SSL_P(F), (gnutls_transport_ptr_t) (long int)F->fd);
-
+ gnutls_priority_set(SSL_P(F), default_priority);
+
rb_settimeout(F, sconn->timeout, rb_ssl_tryconn_timeout_cb, sconn);
- if(do_ssl_handshake(F, rb_ssl_tryconn_cb))
- {
- rb_ssl_connect_realcb(F, RB_OK, sconn);
- }
+ do_ssl_handshake(F, rb_ssl_tryconn_cb, (void *)sconn);
}
int
rb_init_prng(const char *path, prng_seed_t seed_type)
{
+#if GNUTLS_VERSION_MAJOR < 3
gcry_fast_random_poll();
+#endif
return 1;
}
int
rb_get_random(void *buf, size_t length)
{
+#if GNUTLS_VERSION_MAJOR < 3
gcry_randomize(buf, length, GCRY_STRONG_RANDOM);
+#else
+ gnutls_rnd(GNUTLS_RND_KEY, buf, length);
+#endif
return 1;
}
-int
-rb_get_pseudo_random(void *buf, size_t length)
+const char *
+rb_get_ssl_strerror(rb_fde_t *F)
{
- gcry_randomize(buf, length, GCRY_WEAK_RANDOM);
- return 1;
+ return gnutls_strerror(F->ssl_errno);
}
-const char *
-rb_get_ssl_strerror(rb_fde_t * F)
+int
+rb_get_ssl_certfp(rb_fde_t *F, uint8_t certfp[RB_SSL_CERTFP_LEN], int method)
{
- return gnutls_strerror(F->ssl_errno);
+ gnutls_x509_crt_t cert;
+ gnutls_digest_algorithm_t algo;
+ unsigned int cert_list_size;
+ const gnutls_datum_t *cert_list;
+ uint8_t digest[RB_SSL_CERTFP_LEN * 2];
+ size_t digest_size;
+ int len;
+
+ if (gnutls_certificate_type_get(SSL_P(F)) != GNUTLS_CRT_X509)
+ return 0;
+
+ if (gnutls_x509_crt_init(&cert) < 0)
+ return 0;
+
+ cert_list_size = 0;
+ cert_list = gnutls_certificate_get_peers(SSL_P(F), &cert_list_size);
+ if (cert_list == NULL)
+ {
+ gnutls_x509_crt_deinit(cert);
+ return 0;
+ }
+
+ if (gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER) < 0)
+ {
+ gnutls_x509_crt_deinit(cert);
+ return 0;
+ }
+
+ switch(method)
+ {
+ case RB_SSL_CERTFP_METH_SHA1:
+ algo = GNUTLS_DIG_SHA1;
+ len = RB_SSL_CERTFP_LEN_SHA1;
+ break;
+ case RB_SSL_CERTFP_METH_SHA256:
+ algo = GNUTLS_DIG_SHA256;
+ len = RB_SSL_CERTFP_LEN_SHA256;
+ break;
+ case RB_SSL_CERTFP_METH_SHA512:
+ algo = GNUTLS_DIG_SHA512;
+ len = RB_SSL_CERTFP_LEN_SHA512;
+ break;
+ default:
+ return 0;
+ }
+
+ if (gnutls_x509_crt_get_fingerprint(cert, algo, digest, &digest_size) < 0)
+ {
+ gnutls_x509_crt_deinit(cert);
+ return 0;
+ }
+
+ memcpy(certfp, digest, len);
+
+ gnutls_x509_crt_deinit(cert);
+ return len;
}
int
return 1;
}
+void
+rb_get_ssl_info(char *buf, size_t len)
+{
+ snprintf(buf, len, "GNUTLS: compiled (%s), library(%s)",
+ LIBGNUTLS_VERSION, gnutls_check_version(NULL));
+}
+
+const char *
+rb_ssl_get_cipher(rb_fde_t *F)
+{
+ static char buf[1024];
+
+ snprintf(buf, sizeof(buf), "%s-%s-%s-%s",
+ gnutls_protocol_get_name(gnutls_protocol_get_version(SSL_P(F))),
+ gnutls_kx_get_name(gnutls_kx_get(SSL_P(F))),
+ gnutls_cipher_get_name(gnutls_cipher_get(SSL_P(F))),
+ gnutls_mac_get_name(gnutls_mac_get(SSL_P(F))));
+
+ return buf;
+}
+
#endif /* HAVE_GNUTLS */
projects / solanum.git / blobdiff