int
_gnutls_parse_extensions(gnutls_session_t session,
gnutls_ext_parse_type_t parse_type,
const uint8_t * data, int data_size)
{
int next, ret;
int pos = 0;
uint16_t type;
const uint8_t *sdata;
gnutls_ext_recv_func ext_recv;
uint16_t size;
#ifdef DEBUG
int i;
if (session->security_parameters.entity == GNUTLS_CLIENT)
for (i = 0; i < session->internals.extensions_sent_size;
i++) {
_gnutls_handshake_log
("EXT[%d]: expecting extension '%s'\n",
session,
_gnutls_extension_get_name(session->internals.
extensions_sent
[i]));
}
#endif
DECR_LENGTH_RET(data_size, 2, 0);
next = _gnutls_read_uint16(data);
pos += 2;
DECR_LENGTH_RET(data_size, next, 0);
do {
DECR_LENGTH_RET(next, 2, 0);
type = _gnutls_read_uint16(&data[pos]);
pos += 2;
if ((ret =
_gnutls_extension_list_check(session, type)) < 0) {
gnutls_assert();
return ret;
}
DECR_LENGTH_RET(next, 2, 0);
size = _gnutls_read_uint16(&data[pos]);
pos += 2;
DECR_LENGTH_RET(next, size, 0);
sdata = &data[pos];
pos += size;
ext_recv = _gnutls_ext_func_recv(type, parse_type);
if (ext_recv == NULL) {
_gnutls_handshake_log
("EXT[%p]: Found extension '%s/%d'\n", session,
_gnutls_extension_get_name(type), type);
continue;
}
_gnutls_handshake_log
("EXT[%p]: Parsing extension '%s/%d' (%d bytes)\n",
session, _gnutls_extension_get_name(type), type,
size);
if ((ret = ext_recv(session, sdata, size)) < 0) {
gnutls_assert();
return ret;
}
}
while (next > 2);
return 0;
}
int
_gnutls_gen_extensions(gnutls_session_t session,
gnutls_buffer_st * extdata,
gnutls_ext_parse_type_t parse_type)
{
int size;
int pos, size_pos, ret;
size_t i, init_size = extdata->length;
pos = extdata->length; /* we will store length later on */
ret = _gnutls_buffer_append_prefix(extdata, 16, 0);
if (ret < 0)
return gnutls_assert_val(ret);
for (i = 0; i < extfunc_size; i++) {
extension_entry_st *p = &extfunc[i];
if (p->send_func == NULL)
continue;
if (parse_type != GNUTLS_EXT_ANY
&& p->parse_type != parse_type)
continue;
/* ensure we are sending only what we received */
if (session->security_parameters.entity == GNUTLS_SERVER) {
if ((ret =
_gnutls_extension_list_check(session, p->type)) < 0) {
continue;
}
}
ret = _gnutls_buffer_append_prefix(extdata, 16, p->type);
if (ret < 0)
return gnutls_assert_val(ret);
size_pos = extdata->length;
ret = _gnutls_buffer_append_prefix(extdata, 16, 0);
if (ret < 0)
return gnutls_assert_val(ret);
size = p->send_func(session, extdata);
/* returning GNUTLS_E_INT_RET_0 means to send an empty
* extension of this type.
*/
if (size > 0 || size == GNUTLS_E_INT_RET_0) {
if (size == GNUTLS_E_INT_RET_0)
size = 0;
/* write the real size */
_gnutls_write_uint16(size,
&extdata->data[size_pos]);
/* add this extension to the extension list
*/
if (session->security_parameters.entity == GNUTLS_CLIENT)
_gnutls_extension_list_add(session, p->type);
_gnutls_handshake_log
("EXT[%p]: Sending extension %s (%d bytes)\n",
session, p->name, size);
} else if (size < 0) {
gnutls_assert();
return size;
} else if (size == 0)
extdata->length -= 4; /* reset type and size */
}
/* remove any initial data, and the size of the header */
size = extdata->length - init_size - 2;
if (size > 0)
_gnutls_write_uint16(size, &extdata->data[pos]);
else if (size == 0)
extdata->length -= 2; /* the length bytes */
return size;
}
