--- /dev/null
+/*
+ * eap_chbind.c
+ *
+ * Version: $Id$
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * 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 St, Fifth Floor, Boston, MA 02110-1301, USA
+ *
+ * Copyright 2014 Network RADIUS SARL
+ * Copyright 2014 The FreeRADIUS server project
+ */
+
+
+RCSID("$Id$")
+
+#include "eap_chbind.h"
+
+#define MAX_PACKET_LEN 4096
+
+static bool chbind_build_response(REQUEST *request, CHBIND_REQ *chbind)
+{
+ size_t length, total;
+ uint8_t *ptr, *end;
+ VALUE_PAIR const *vp;
+ vp_cursor_t cursor;
+
+ total = 0;
+ for (vp = fr_cursor_init(&cursor, &request->reply->vps);
+ vp != NULL;
+ vp = fr_cursor_next(&cursor)) {
+ /*
+ * Skip things which shouldn't be in channel bindings.
+ */
+ if (vp->da->flags.encrypt != FLAG_ENCRYPT_NONE) continue;
+ if (!vp->da->vendor && (vp->da->attr == PW_MESSAGE_AUTHENTICATOR)) continue;
+
+ total = 2 + vp->length;
+ }
+
+ /*
+ * No attributes: just send a 1-byte response code.
+ */
+ if (!total) {
+ ptr = talloc_zero_array(chbind, uint8_t, 1);
+ } else {
+ ptr = talloc_zero_array(chbind, uint8_t, total + 4);
+ }
+ if (!ptr) return false;
+ chbind->response = (chbind_packet_t *) ptr;
+
+ /*
+ * Set the response code. Default to "fail" if none was
+ * specified.
+ */
+ vp = pairfind(request->config_items, PW_CHBIND_RESPONSE_CODE, 0, TAG_ANY);
+ if (vp) {
+ ptr[0] = vp->vp_integer;
+ } else {
+ ptr[0] = CHBIND_CODE_FAILURE;
+ }
+
+ if (!total) return true; /* nothing to encode */
+
+ /* Write the length field into the header */
+ ptr[1] = (total >> 8) & 0xff;
+ ptr[2] = total & 0xff;
+ ptr[3] = CHBIND_NSID_RADIUS;
+
+ if ((debug_flag > 0) && fr_log_fp) {
+ RDEBUG("Sending chbind response: code %i", (int )(ptr[0]));
+ debug_pair_list(request->reply->vps);
+ }
+
+ /* Encode the chbind attributes into the response */
+ ptr += 4;
+ end = ptr + total;
+ for (vp = fr_cursor_init(&cursor, &request->reply->vps);
+ vp != NULL;
+ vp = fr_cursor_next(&cursor)) {
+ length = rad_vp2attr(NULL, NULL, NULL, &vp, ptr, end - ptr);
+ ptr += length;
+ }
+
+ return true;
+}
+
+
+/*
+ * Parse channel binding packet to obtain data for a specific
+ * NSID.
+ *
+ * See:
+ * http://tools.ietf.org/html/draft-ietf-emu-chbind-13#section-5.3.2
+ */
+static size_t chbind_get_data(chbind_packet_t const *packet,
+ int desired_nsid,
+ uint8_t const **data)
+{
+ uint8_t const *ptr;
+ uint8_t const *end;
+
+ if (packet->code != CHBIND_CODE_REQUEST) {
+ return 0;
+ }
+
+ ptr = (uint8_t const *) packet;
+ end = ptr + talloc_array_length(packet);
+
+ ptr++; /* skip the code at the start of the packet */
+ while (ptr < end) {
+ uint8_t nsid;
+ size_t length;
+
+ /*
+ * Need room for length(2) + NSID + data.
+ */
+ if ((end - ptr) < 4) return 0;
+
+ length = (ptr[0] << 8) | ptr[1];
+ if (length == 0) return 0;
+
+ if ((ptr + length + 3) > end) return 0;
+
+ nsid = ptr[2];
+ if (nsid == desired_nsid) {
+ ptr += 3;
+ *data = ptr;
+ return length;
+ }
+
+ ptr += 3 + length;
+ }
+
+ return 0;
+}
+
+
+PW_CODE chbind_process(REQUEST *request, CHBIND_REQ *chbind)
+{
+ PW_CODE rcode;
+ REQUEST *fake = NULL;
+ VALUE_PAIR *vp = NULL;
+ uint8_t const *attr_data;
+ size_t data_len = 0;
+
+ /* check input parameters */
+ rad_assert((request != NULL) &&
+ (chbind != NULL) &&
+ (chbind->request != NULL) &&
+ (chbind->response == NULL));
+
+ /* Set-up the fake request */
+ fake = request_alloc_fake(request);
+ pairmake_packet("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
+
+ /* Add the username to the fake request */
+ if (chbind->username) {
+ vp = paircopyvp(fake->packet, chbind->username);
+ pairadd(&fake->packet->vps, vp);
+ fake->username = vp;
+ }
+
+ /*
+ * Maybe copy the State over, too?
+ */
+
+ /* Add the channel binding attributes to the fake packet */
+ data_len = chbind_get_data(chbind->request, CHBIND_NSID_RADIUS, &attr_data);
+ if (data_len) {
+ while (data_len > 0) {
+ int attr_len = rad_attr2vp(fake->packet, NULL, NULL, NULL, attr_data, data_len, &vp);
+ if (attr_len <= 0) {
+ /* If radaddr2vp fails, return NULL string for
+ channel binding response */
+ talloc_free(fake);
+ return PW_CODE_ACCESS_ACCEPT;
+ }
+ if (vp) {
+ pairadd(&fake->packet->vps, vp);
+ }
+ attr_data += attr_len;
+ data_len -= attr_len;
+ }
+ }
+
+ /*
+ * Set virtual server based on configuration for channel
+ * bindings, this is hard-coded for now.
+ */
+ fake->server = "channel_bindings";
+ fake->packet->code = PW_CODE_ACCESS_REQUEST;
+
+ rcode = rad_virtual_server(fake);
+
+ switch (rcode) {
+ /* If rad_authenticate succeeded, build a reply */
+ case RLM_MODULE_OK:
+ case RLM_MODULE_HANDLED:
+ if (chbind_build_response(fake, chbind)) {
+ rcode = PW_CODE_ACCESS_ACCEPT;
+ break;
+ }
+ /* FALL-THROUGH */
+
+ /* If we got any other response from rad_authenticate, it maps to a reject */
+ default:
+ rcode = PW_CODE_ACCESS_REJECT;
+ break;
+ }
+
+ talloc_free(fake);
+
+ return rcode;
+}
+
+/*
+ * Handles multiple EAP-channel-binding Message attrs
+ * ie concatenates all to get the complete EAP-channel-binding packet.
+ */
+chbind_packet_t *eap_chbind_vp2packet(TALLOC_CTX *ctx, VALUE_PAIR *vps)
+{
+ size_t length;
+ uint8_t *ptr;
+ VALUE_PAIR *first, *vp;
+ chbind_packet_t *packet;
+ vp_cursor_t cursor;
+
+ first = pairfind(vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, TAG_ANY);
+ if (!first) return NULL;
+
+ /*
+ * Compute the total length of the channel binding data.
+ */
+ length = 0;
+ for (vp =fr_cursor_init(&cursor, first);
+ vp != NULL;
+ vp = fr_cursor_next_by_num(&cursor, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, TAG_ANY)) {
+ length += vp->length;
+ }
+
+ if (length < 4) {
+ DEBUG("Invalid length %u for channel binding data", (unsigned int) length);
+ return NULL;
+ }
+
+ /*
+ * Now that we know the length, allocate memory for the packet.
+ */
+ ptr = talloc_zero_array(ctx, uint8_t, length);
+ if (!ptr) return NULL;
+
+ /*
+ * Copy the data over to our packet.
+ */
+ packet = (chbind_packet_t *) ptr;
+ for (vp = fr_cursor_init(&cursor, first);
+ vp != NULL;
+ vp = fr_cursor_next_by_num(&cursor, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, TAG_ANY)) {
+ memcpy(ptr, vp->vp_octets, vp->length);
+ ptr += vp->length;
+ }
+
+ return packet;
+}
+
+VALUE_PAIR *eap_chbind_packet2vp(REQUEST *request, const chbind_packet_t *packet)
+{
+ VALUE_PAIR *vp;
+
+ if (!packet) return NULL; /* don't produce garbage */
+
+ vp = paircreate(request->packet, PW_UKERNA_CHBIND, VENDORPEC_UKERNA);
+ if (!vp) return NULL;
+ pairmemcpy(vp, (const uint8_t *) packet, talloc_array_length(packet));
+
+ return vp;
+}
--- /dev/null
+/*
+ * eap_chbind.c
+ *
+ * Version: $Id$
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * 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 St, Fifth Floor, Boston, MA 02110-1301, USA
+ *
+ * Copyright 2014 Network RADIUS SARL
+ * Copyright 2014 The FreeRADIUS server project
+ */
+
+#ifndef _EAP_CHBIND_H
+#define _EAP_CHBIND_H
+
+RCSIDH(eap_chbind_h, "$Id$")
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <ctype.h>
+
+#include <freeradius-devel/radiusd.h>
+
+#include "eap.h"
+
+/* Structure to represent eap channel binding packet format */
+typedef struct chbind_packet_t {
+ uint8_t code;
+ uint8_t data[1];
+} chbind_packet_t;
+
+/* Structure to hold channel bindings req/resp information */
+typedef struct CHBIND_REQ {
+ VALUE_PAIR *username; /* the username */
+ chbind_packet_t *request; /* channel binding request buffer */
+ chbind_packet_t *response; /* channel binding response buffer */
+} CHBIND_REQ;
+
+/* Protocol constants */
+#define CHBIND_NSID_RADIUS 1
+
+#define CHBIND_CODE_REQUEST 1
+#define CHBIND_CODE_SUCCESS 2
+#define CHBIND_CODE_FAILURE 3
+
+/* Channel binding function prototypes */
+PW_CODE chbind_process(REQUEST *request, CHBIND_REQ *chbind_req);
+
+extern VALUE_PAIR *eap_chbind_packet2vp(REQUEST *request, const chbind_packet_t *packet);
+extern chbind_packet_t *eap_chbind_vp2packet(TALLOC_CTX *ctx, VALUE_PAIR *vps);
+
+#endif /*_EAP_CHBIND_H*/
projects / freeradius.git / commitdiff