diff options
Diffstat (limited to 'src/modules/rlm_eap/types/rlm_eap_ttls/ttls.c')
| -rw-r--r-- | src/modules/rlm_eap/types/rlm_eap_ttls/ttls.c | 1321 |
1 files changed, 1321 insertions, 0 deletions
diff --git a/src/modules/rlm_eap/types/rlm_eap_ttls/ttls.c b/src/modules/rlm_eap/types/rlm_eap_ttls/ttls.c new file mode 100644 index 0000000..cbe4239 --- /dev/null +++ b/src/modules/rlm_eap/types/rlm_eap_ttls/ttls.c @@ -0,0 +1,1321 @@ +/* + * rlm_eap_ttls.c contains the interfaces that are called from eap + * + * 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 2003 Alan DeKok <aland@freeradius.org> + * Copyright 2006 The FreeRADIUS server project + */ + +RCSID("$Id$") + +#include "eap_ttls.h" +#include "eap_chbind.h" + +/* + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | AVP Code | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |V M r r r r r r| AVP Length | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Vendor-ID (opt) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Data ... + * +-+-+-+-+-+-+-+-+ + */ + +/* + * Verify that the diameter packet is valid. + */ +static int diameter_verify(REQUEST *request, uint8_t const *data, unsigned int data_len) +{ + uint32_t attr; + uint32_t length; + unsigned int hdr_len; + unsigned int remaining = data_len; + + while (remaining > 0) { + hdr_len = 12; + + if (remaining < hdr_len) { + RDEBUG2("Diameter attribute is too small (%u) to contain a Diameter header", remaining); + return 0; + } + + memcpy(&attr, data, sizeof(attr)); + attr = ntohl(attr); + memcpy(&length, data + 4, sizeof(length)); + length = ntohl(length); + + if ((data[4] & 0x80) != 0) { + if (remaining < 16) { + RDEBUG2("Diameter attribute is too small to contain a Diameter header with Vendor-Id"); + return 0; + } + + hdr_len = 16; + } + + /* + * Get the length. If it's too big, die. + */ + length &= 0x00ffffff; + + /* + * Too short or too long is bad. + */ + if (length <= (hdr_len - 4)) { + RDEBUG2("Tunneled attribute %u is too short (%u < %u) to contain anything useful.", attr, + length, hdr_len); + return 0; + } + + if (length > remaining) { + RDEBUG2("Tunneled attribute %u is longer than room remaining in the packet (%u > %u).", attr, + length, remaining); + return 0; + } + + /* + * Check for broken implementations, which don't + * pad the AVP to a 4-octet boundary. + */ + if (remaining == length) break; + + /* + * The length does NOT include the padding, so + * we've got to account for it here by rounding up + * to the nearest 4-byte boundary. + */ + length += 0x03; + length &= ~0x03; + + /* + * If the rest of the diameter packet is larger than + * this attribute, continue. + * + * Otherwise, if the attribute over-flows the end + * of the packet, die. + */ + if (remaining < length) { + REDEBUG2("Diameter attribute overflows packet!"); + return 0; + } + + /* + * remaining > length, continue. + */ + remaining -= length; + data += length; + } + + /* + * We got this far. It looks OK. + */ + return 1; +} + + +/* + * Convert diameter attributes to our VALUE_PAIR's + */ +static VALUE_PAIR *diameter2vp(REQUEST *request, REQUEST *fake, SSL *ssl, + uint8_t const *data, size_t data_len) +{ + uint32_t attr; + uint32_t vendor; + uint32_t length; + size_t offset; + size_t size; + size_t data_left = data_len; + VALUE_PAIR *first = NULL; + VALUE_PAIR *vp = NULL; + RADIUS_PACKET *packet = fake->packet; /* FIXME: api issues */ + vp_cursor_t out; + DICT_ATTR const *da; + + fr_cursor_init(&out, &first); + + /* + * Parse while there's still data. + */ + while (data_left >= 9) { + size_t attr_len; + + rad_assert(data_left <= data_len); + memcpy(&attr, data, sizeof(attr)); + data += 4; + attr = ntohl(attr); + vendor = 0; + + memcpy(&length, data, sizeof(length)); + data += 4; + length = ntohl(length); + + /* + * Length is *value* length. The actual + * attributes are aligned on 4 octets. + */ + attr_len = length & 0x00ffffff; + attr_len += 0x03; + attr_len &= ~(uint32_t) 0x03; + + /* + * A "vendor" flag, with a vendor ID of zero, + * is equivalent to no vendor. This is stupid. + */ + offset = 8; + if ((length & ((uint32_t)1 << 31)) != 0) { + memcpy(&vendor, data, sizeof(vendor)); + vendor = ntohl(vendor); + + data += 4; /* skip the vendor field, it's zero */ + offset += 4; /* offset to value field */ + + if (attr > 65535) { + DEBUG("Skipping Diameter attribute %08x", attr); + goto next_attr; + } + if (vendor > FR_MAX_VENDOR) { + DEBUG("Skipping large vendor ID %08x", vendor); + goto next_attr; + } + } + + /* + * FIXME: Handle the M bit. For now, we assume that + * some other module takes care of any attribute + * with the M bit set. + */ + + /* + * Get the length. + */ + length &= 0x00ffffff; + + /* + * Get the size of the value portion of the + * attribute. + */ + size = length - offset; + + /* + * Vendor attributes can be larger than 255. + * Normal attributes cannot be. + */ + if ((attr > 255) && (vendor == 0)) { + RWDEBUG2("Skipping Diameter attribute %u", attr); + goto next_attr; + } + + /* + * EAP-Message AVPs can be larger than 253 octets. + * + * For now, we rely on the main decoder in + * src/lib/radius to decode data into VPs. This + * means putting the data into a RADIUS attribute + * format. It also means that we can't handle + * "extended" attributes in the Diameter space. Oh well... + */ + if ((size > 253) && !((vendor == 0) && (attr == PW_EAP_MESSAGE))) { + RWDEBUG2("diameter2vp skipping long attribute %u", attr); + goto next_attr; + } + + /* + * RADIUS VSAs are handled as Diameter attributes + * with Vendor-Id == 0, and the VSA data packed + * into the "String" field as per normal. + * + * EXCEPT for the MS-CHAP attributes. + */ + if ((vendor == 0) && (attr == PW_VENDOR_SPECIFIC)) { + ssize_t decoded; + uint8_t buffer[256]; + + buffer[0] = PW_VENDOR_SPECIFIC; + buffer[1] = size + 2; + memcpy(buffer + 2, data, size); + + vp = NULL; + decoded = rad_attr2vp(packet, NULL, NULL, NULL, + buffer, size + 2, &vp); + if (decoded < 0) { + REDEBUG2("diameter2vp failed decoding attr: %s", + fr_strerror()); + goto raw; + } + + if ((size_t) decoded != size + 2) { + REDEBUG2("diameter2vp failed to entirely decode VSA"); + fr_pair_list_free(&vp); + goto raw; + } + + fr_cursor_merge(&out, vp); + + goto next_attr; + } + + /* + * Create it. If this fails, it's because we're OOM. + */ + da = dict_attrbyvalue(attr, vendor); + if (!da) goto raw; + + vp = fr_pair_afrom_da(packet, da); + if (!vp) { + RDEBUG2("Failure in creating VP"); + fr_pair_list_free(&first); + return NULL; + } + + /* + * If it's a type from our dictionary, then + * we need to put the data in a relevant place. + * + * @todo: Export the lib/radius.c decoder, and use it here! + */ + switch (vp->da->type) { + case PW_TYPE_INTEGER: + case PW_TYPE_DATE: + if (size != vp->vp_length) { + /* + * Bad format. Create a "raw" + * attribute. + */ + raw: + if (vp) fr_pair_list_free(&vp); + da = dict_unknown_afrom_fields(packet, attr, vendor); + if (!da) return NULL; + vp = fr_pair_afrom_da(packet, da); + if (!vp) return NULL; + fr_pair_value_memcpy(vp, data, size); + break; + } + memcpy(&vp->vp_integer, data, vp->vp_length); + + /* + * Stored in host byte order: change it. + */ + vp->vp_integer = ntohl(vp->vp_integer); + break; + + case PW_TYPE_INTEGER64: + if (size != vp->vp_length) goto raw; + memcpy(&vp->vp_integer64, data, vp->vp_length); + + /* + * Stored in host byte order: change it. + */ + vp->vp_integer64 = ntohll(vp->vp_integer64); + break; + + case PW_TYPE_IPV4_ADDR: + if (size != vp->vp_length) { + RDEBUG2("Invalid length attribute %d", + attr); + fr_pair_list_free(&first); + fr_pair_list_free(&vp); + return NULL; + } + memcpy(&vp->vp_ipaddr, data, vp->vp_length); + + /* + * Stored in network byte order: don't change it. + */ + break; + + case PW_TYPE_BYTE: + if (size != vp->vp_length) goto raw; + vp->vp_byte = data[0]; + break; + + case PW_TYPE_SHORT: + if (size != vp->vp_length) goto raw; + vp->vp_short = (data[0] * 256) + data[1]; + break; + + case PW_TYPE_SIGNED: + if (size != vp->vp_length) goto raw; + memcpy(&vp->vp_signed, data, vp->vp_length); + vp->vp_signed = ntohl(vp->vp_signed); + break; + + case PW_TYPE_IPV6_ADDR: + if (size != vp->vp_length) goto raw; + memcpy(&vp->vp_ipv6addr, data, vp->vp_length); + break; + + case PW_TYPE_IPV6_PREFIX: + if (size != vp->vp_length) goto raw; + memcpy(vp->vp_ipv6prefix, data, vp->vp_length); + break; + + case PW_TYPE_STRING: + fr_pair_value_bstrncpy(vp, data, size); + vp->vp_length = strlen(vp->vp_strvalue); /* embedded zeros are NOT allowed */ + break; + + /* + * Copy it over verbatim. + */ + case PW_TYPE_OCTETS: + default: + fr_pair_value_memcpy(vp, data, size); + break; + } + + /* + * Ensure that the client is using the + * correct challenge. This weirdness is + * to protect against against replay + * attacks, where anyone observing the + * CHAP exchange could pose as that user, + * by simply choosing to use the same + * challenge. + * + * By using a challenge based on + * information from the current session, + * we can guarantee that the client is + * not *choosing* a challenge. + * + * We're a little forgiving in that we + * have loose checks on the length, and + * we do NOT check the Id (first octet of + * the response to the challenge) + * + * But if the client gets the challenge correct, + * we're not too worried about the Id. + */ + if (((vp->da->vendor == 0) && (vp->da->attr == PW_CHAP_CHALLENGE)) || + ((vp->da->vendor == VENDORPEC_MICROSOFT) && (vp->da->attr == PW_MSCHAP_CHALLENGE))) { + uint8_t challenge[17]; + + if ((vp->vp_length < 8) || + (vp->vp_length > 16)) { + RDEBUG("Tunneled challenge has invalid length"); + fr_pair_list_free(&first); + fr_pair_list_free(&vp); + return NULL; + } + + /* + * TLSv1.3 exports a different key depending on the length + * requested so ask for *exactly* what the spec requires + */ + eapttls_gen_challenge(ssl, challenge, vp->vp_length + 1); + + if (memcmp(challenge, vp->vp_octets, + vp->vp_length) != 0) { + RDEBUG("Tunneled challenge is incorrect"); + fr_pair_list_free(&first); + fr_pair_list_free(&vp); + return NULL; + } + } + + /* + * Update the list. + */ + fr_cursor_insert(&out, vp); + + next_attr: + if (data_left <= attr_len) break; + + data_left -= attr_len; + data += (attr_len - offset); + } + + /* + * We got this far. It looks OK. + */ + return first; +} + +/* + * Convert VALUE_PAIR's to diameter attributes, and write them + * to an SSL session. + * + * The ONLY VALUE_PAIR's which may be passed to this function + * are ones which can go inside of a RADIUS (i.e. diameter) + * packet. So no server-configuration attributes, or the like. + */ +static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first) +{ + /* + * RADIUS packets are no more than 4k in size, so if + * we've got more than 4k of data to write, it's very + * bad. + */ + uint8_t buffer[4096]; + uint8_t *p; + uint32_t attr; + uint32_t length; + uint32_t vendor; + size_t total; + uint64_t attr64; + VALUE_PAIR *vp; + vp_cursor_t cursor; + + p = buffer; + total = 0; + + for (vp = fr_cursor_init(&cursor, &first); vp; vp = fr_cursor_next(&cursor)) { + /* + * Too much data: die. + */ + if ((total + vp->vp_length + 12) >= sizeof(buffer)) { + RDEBUG2("output buffer is full!"); + return 0; + } + + /* + * Hmm... we don't group multiple EAP-Messages + * together. Maybe we should... + */ + + length = vp->vp_length; + vendor = vp->da->vendor; + if (vendor != 0) { + attr = vp->da->attr & 0xffff; + length |= ((uint32_t)1 << 31); + } else { + attr = vp->da->attr; + } + + /* + * Hmm... set the M bit for all attributes? + */ + length |= (1 << 30); + + attr = ntohl(attr); + + memcpy(p, &attr, sizeof(attr)); + p += 4; + total += 4; + + length += 8; /* includes 8 bytes of attr & length */ + + if (vendor != 0) { + length += 4; /* include 4 bytes of vendor */ + + length = ntohl(length); + memcpy(p, &length, sizeof(length)); + p += 4; + total += 4; + + vendor = ntohl(vendor); + memcpy(p, &vendor, sizeof(vendor)); + p += 4; + total += 4; + } else { + length = ntohl(length); + memcpy(p, &length, sizeof(length)); + p += 4; + total += 4; + } + + switch (vp->da->type) { + case PW_TYPE_INTEGER: + case PW_TYPE_DATE: + attr = htonl(vp->vp_integer); /* stored in host order */ + memcpy(p, &attr, sizeof(attr)); + length = 4; + break; + + case PW_TYPE_INTEGER64: + attr64 = htonll(vp->vp_integer64); /* stored in host order */ + memcpy(p, &attr64, sizeof(attr64)); + length = 8; + break; + + case PW_TYPE_IPV4_ADDR: + memcpy(p, &vp->vp_ipaddr, 4); /* network order */ + length = 4; + break; + + case PW_TYPE_STRING: + case PW_TYPE_OCTETS: + default: + memcpy(p, vp->vp_strvalue, vp->vp_length); + length = vp->vp_length; + break; + } + + /* + * Skip to the end of the data. + */ + p += length; + total += length; + + /* + * Align the data to a multiple of 4 bytes. + */ + if ((total & 0x03) != 0) { + size_t i; + + length = 4 - (total & 0x03); + for (i = 0; i < length; i++) { + *p = '\0'; + p++; + total++; + } + } + } /* loop over the VP's to write. */ + + /* + * Write the data in the buffer to the SSL session. + */ + if (total > 0) { +#ifndef NDEBUG + size_t i; + + if ((rad_debug_lvl > 2) && fr_log_fp) { + for (i = 0; i < total; i++) { + if ((i & 0x0f) == 0) fprintf(fr_log_fp, " TTLS tunnel data out %04x: ", (int) i); + + fprintf(fr_log_fp, "%02x ", buffer[i]); + + if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n"); + } + if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n"); + } +#endif + + (tls_session->record_plus)(&tls_session->clean_in, buffer, total); + + /* + * FIXME: Check the return code. + */ + tls_handshake_send(request, tls_session); + } + + /* + * Everything's OK. + */ + return 1; +} + +/* + * Use a reply packet to determine what to do. + */ +static rlm_rcode_t CC_HINT(nonnull) process_reply(eap_handler_t *handler, tls_session_t *tls_session, + REQUEST *request, RADIUS_PACKET *reply) +{ + rlm_rcode_t rcode = RLM_MODULE_REJECT; + VALUE_PAIR *vp; + ttls_tunnel_t *t = tls_session->opaque; + + rad_assert(handler->request == request); + + /* + * If the response packet was Access-Accept, then + * we're OK. If not, die horribly. + * + * FIXME: Take MS-CHAP2-Success attribute, and + * tunnel it back to the client, to authenticate + * ourselves to the client. + * + * FIXME: If we have an Access-Challenge, then + * the Reply-Message is tunneled back to the client. + * + * FIXME: If we have an EAP-Message, then that message + * must be tunneled back to the client. + * + * FIXME: If we have an Access-Challenge with a State + * attribute, then do we tunnel that to the client, or + * keep track of it ourselves? + * + * FIXME: EAP-Messages can only start with 'identity', + * NOT 'eap start', so we should check for that.... + */ + switch (reply->code) { + case PW_CODE_ACCESS_ACCEPT: + tls_session->authentication_success = true; + RDEBUG("Got tunneled Access-Accept"); + + rcode = RLM_MODULE_OK; + + /* + * Always delete MPPE keys & encryption policy + * from the tunneled reply. These never get sent + * back to the user. + */ + fr_pair_delete_by_num(&reply->vps, 7, VENDORPEC_MICROSOFT, TAG_ANY); + fr_pair_delete_by_num(&reply->vps, 8, VENDORPEC_MICROSOFT, TAG_ANY); + fr_pair_delete_by_num(&reply->vps, 16, VENDORPEC_MICROSOFT, TAG_ANY); + fr_pair_delete_by_num(&reply->vps, 17, VENDORPEC_MICROSOFT, TAG_ANY); + + /* + * MS-CHAP2-Success means that we do NOT return + * an Access-Accept, but instead tunnel that + * attribute to the client, and keep going with + * the TTLS session. Once the client accepts + * our identity, it will respond with an empty + * packet, and we will send EAP-Success. + */ + vp = NULL; + fr_pair_list_mcopy_by_num(tls_session, &vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT, TAG_ANY); + if (vp) { + RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge"); + rcode = RLM_MODULE_HANDLED; + t->authenticated = true; + + /* + * Use the tunneled reply, but not now. + */ + if (t->use_tunneled_reply) { + rad_assert(!t->accept_vps); + fr_pair_list_mcopy_by_num(t, &t->accept_vps, &reply->vps, + 0, 0, TAG_ANY); + rad_assert(!reply->vps); + } + + } else { /* no MS-CHAP2-Success */ + /* + * Can only have EAP-Message if there's + * no MS-CHAP2-Success. + * + * We also do NOT tunnel the EAP-Success + * attribute back to the client, as the client + * can figure it out, from the non-tunneled + * EAP-Success packet. + */ + fr_pair_list_mcopy_by_num(tls_session, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY); + fr_pair_list_free(&vp); + } + + /* move channel binding responses; we need to send them */ + fr_pair_list_mcopy_by_num(tls_session, &vp, &reply->vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, TAG_ANY); + if (fr_pair_find_by_num(vp, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, TAG_ANY) != NULL) { + t->authenticated = true; + /* + * Use the tunneled reply, but not now. + */ + if (t->use_tunneled_reply) { + rad_assert(!t->accept_vps); + fr_pair_list_mcopy_by_num(t, &t->accept_vps, &reply->vps, + 0, 0, TAG_ANY); + rad_assert(!reply->vps); + } + rcode = RLM_MODULE_HANDLED; + } + + /* + * Handle the ACK, by tunneling any necessary reply + * VP's back to the client. + */ + if (vp) { + RDEBUG("Sending tunneled reply attributes"); + rdebug_pair_list(L_DBG_LVL_1, request, vp, NULL); + + vp2diameter(request, tls_session, vp); + fr_pair_list_free(&vp); + } + + /* + * If we've been told to use the attributes from + * the reply, then do so. + * + * WARNING: This may leak information about the + * tunneled user! + */ + if (t->use_tunneled_reply) { + fr_pair_delete_by_num(&reply->vps, PW_PROXY_STATE, 0, TAG_ANY); + fr_pair_list_mcopy_by_num(request->reply, &request->reply->vps, + &reply->vps, 0, 0, TAG_ANY); + } + break; + + + case PW_CODE_ACCESS_REJECT: + RDEBUG("Got tunneled Access-Reject"); + rcode = RLM_MODULE_REJECT; + break; + + /* + * Handle Access-Challenge, but only if we + * send tunneled reply data. This is because + * an Access-Challenge means that we MUST tunnel + * a Reply-Message to the client. + */ + case PW_CODE_ACCESS_CHALLENGE: + RDEBUG("Got tunneled Access-Challenge"); + + /* + * Keep the State attribute, if necessary. + * + * Get rid of the old State, too. + */ + fr_pair_list_free(&t->state); + fr_pair_list_mcopy_by_num(t, &t->state, &reply->vps, PW_STATE, 0, TAG_ANY); + + /* + * We should really be a bit smarter about this, + * and move over only those attributes which + * are relevant to the authentication request, + * but that's a lot more work, and this "dumb" + * method works in 99.9% of the situations. + */ + vp = NULL; + fr_pair_list_mcopy_by_num(t, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY); + + /* + * There MUST be a Reply-Message in the challenge, + * which we tunnel back to the client. + * + * If there isn't one in the reply VP's, then + * we MUST create one, with an empty string as + * it's value. + */ + fr_pair_list_mcopy_by_num(t, &vp, &reply->vps, PW_REPLY_MESSAGE, 0, TAG_ANY); + + /* also move chbind messages, if any */ + fr_pair_list_mcopy_by_num(t, &vp, &reply->vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, + TAG_ANY); + + /* + * Handle the ACK, by tunneling any necessary reply + * VP's back to the client. + */ + if (vp) { + vp2diameter(request, tls_session, vp); + fr_pair_list_free(&vp); + } + rcode = RLM_MODULE_HANDLED; + break; + + default: + RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code); + rcode = RLM_MODULE_INVALID; + break; + } + + return rcode; +} + + +#ifdef WITH_PROXY +/* + * Do post-proxy processing, + */ +static int CC_HINT(nonnull) eapttls_postproxy(eap_handler_t *handler, void *data) +{ + int rcode; + tls_session_t *tls_session = (tls_session_t *) data; + REQUEST *fake, *request = handler->request; + + RDEBUG("Passing reply from proxy back into the tunnel"); + + /* + * If there was a fake request associated with the proxied + * request, do more processing of it. + */ + fake = (REQUEST *) request_data_get(handler->request, + handler->request->proxy, + REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK); + + /* + * Do the callback, if it exists, and if it was a success. + */ + if (fake && (handler->request->proxy_reply->code == PW_CODE_ACCESS_ACCEPT)) { + /* + * Terrible hacks. + */ + rad_assert(!fake->packet); + fake->packet = talloc_steal(fake, request->proxy); + fake->packet->src_ipaddr = request->packet->src_ipaddr; + request->proxy = NULL; + + rad_assert(!fake->reply); + fake->reply = talloc_steal(fake, request->proxy_reply); + request->proxy_reply = NULL; + + if ((rad_debug_lvl > 0) && fr_log_fp) { + fprintf(fr_log_fp, "server %s {\n", + (!fake->server) ? "" : fake->server); + } + + /* + * Perform a post-auth stage for the tunneled + * session. + */ + fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP; + rcode = rad_postauth(fake); + RDEBUG2("post-auth returns %d", rcode); + + if ((rad_debug_lvl > 0) && fr_log_fp) { + fprintf(fr_log_fp, "} # server %s\n", + (!fake->server) ? "" : fake->server); + + RDEBUG("Final reply from tunneled session code %d", fake->reply->code); + rdebug_pair_list(L_DBG_LVL_1, request, fake->reply->vps, NULL); + } + + /* + * Terrible hacks. + */ + request->proxy = talloc_steal(request, fake->packet); + fake->packet = NULL; + request->proxy_reply = talloc_steal(request, fake->reply); + fake->reply = NULL; + + /* + * And we're done with this request. + */ + + switch (rcode) { + case RLM_MODULE_FAIL: + talloc_free(fake); + eaptls_fail(handler, 0); + return 0; + + default: /* Don't Do Anything */ + RDEBUG2("Got reply %d", + request->proxy_reply->code); + break; + } + } + talloc_free(fake); /* robust if !fake */ + + /* + * Process the reply from the home server. + */ + rcode = process_reply(handler, tls_session, handler->request, handler->request->proxy_reply); + + /* + * The proxy code uses the reply from the home server as + * the basis for the reply to the NAS. We don't want that, + * so we toss it, after we've had our way with it. + */ + fr_pair_list_free(&handler->request->proxy_reply->vps); + + switch (rcode) { + case RLM_MODULE_REJECT: + RDEBUG("Reply was rejected"); + break; + + case RLM_MODULE_HANDLED: + RDEBUG("Reply was handled"); + eaptls_request(handler->eap_ds, tls_session); + request->proxy_reply->code = PW_CODE_ACCESS_CHALLENGE; + return 1; + + case RLM_MODULE_OK: + RDEBUG("Reply was OK"); + + /* + * Success: Automatically return MPPE keys. + */ + return eaptls_success(handler, 0); + + default: + RDEBUG("Reply was unknown"); + break; + } + + eaptls_fail(handler, 0); + return 0; +} + +#endif /* WITH_PROXY */ + +/* + * Process the "diameter" contents of the tunneled data. + */ +int eapttls_process(eap_handler_t *handler, tls_session_t *tls_session) +{ + PW_CODE code = PW_CODE_ACCESS_REJECT; + rlm_rcode_t rcode; + REQUEST *fake; + VALUE_PAIR *vp; + ttls_tunnel_t *t; + uint8_t const *data; + size_t data_len; + REQUEST *request = handler->request; + chbind_packet_t *chbind; + + /* + * Just look at the buffer directly, without doing + * record_minus. + */ + data_len = tls_session->clean_out.used; + tls_session->clean_out.used = 0; + data = tls_session->clean_out.data; + + t = (ttls_tunnel_t *) tls_session->opaque; + + /* + * If there's no data, maybe this is an ACK to an + * MS-CHAP2-Success. + */ + if (data_len == 0) { + if (t->authenticated) { + RDEBUG("Got ACK, and the user was already authenticated"); + return PW_CODE_ACCESS_ACCEPT; + } /* else no session, no data, die. */ + + /* + * FIXME: Call SSL_get_error() to see what went + * wrong. + */ + RDEBUG2("SSL_read Error"); + return PW_CODE_ACCESS_REJECT; + } + +#ifndef NDEBUG + if ((rad_debug_lvl > 2) && fr_log_fp) { + size_t i; + + for (i = 0; i < data_len; i++) { + if ((i & 0x0f) == 0) fprintf(fr_log_fp, " TTLS tunnel data in %04x: ", (int) i); + + fprintf(fr_log_fp, "%02x ", data[i]); + + if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n"); + } + if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n"); + } +#endif + + if (!diameter_verify(request, data, data_len)) { + return PW_CODE_ACCESS_REJECT; + } + + /* + * Allocate a fake REQUEST structure. + */ + fake = request_alloc_fake(request); + + rad_assert(!fake->packet->vps); + + /* + * Add the tunneled attributes to the fake request. + */ + fake->packet->vps = diameter2vp(request, fake, tls_session->ssl, data, data_len); + if (!fake->packet->vps) { + talloc_free(fake); + return PW_CODE_ACCESS_REJECT; + } + + /* + * Tell the request that it's a fake one. + */ + fr_pair_make(fake->packet, &fake->packet->vps, "Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ); + + RDEBUG("Got tunneled request"); + rdebug_pair_list(L_DBG_LVL_1, request, fake->packet->vps, NULL); + + /* + * Update other items in the REQUEST data structure. + */ + fake->username = fr_pair_find_by_num(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY); + fake->password = fr_pair_find_by_num(fake->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY); + + /* + * No User-Name, try to create one from stored data. + */ + if (!fake->username) { + /* + * No User-Name in the stored data, look for + * an EAP-Identity, and pull it out of there. + */ + if (!t->username) { + vp = fr_pair_find_by_num(fake->packet->vps, PW_EAP_MESSAGE, 0, TAG_ANY); + if (vp && + (vp->vp_length >= EAP_HEADER_LEN + 2) && + (vp->vp_strvalue[0] == PW_EAP_RESPONSE) && + (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) && + (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) { + /* + * Create & remember a User-Name + */ + t->username = fr_pair_make(t, NULL, "User-Name", NULL, T_OP_EQ); + rad_assert(t->username != NULL); + + fr_pair_value_bstrncpy(t->username, vp->vp_octets + 5, vp->vp_length - 5); + + RDEBUG("Got tunneled identity of %s", + t->username->vp_strvalue); + + /* + * If there's a default EAP type, + * set it here. + */ + if (t->default_method != 0) { + RDEBUG("Setting default EAP type for tunneled EAP session"); + vp = fr_pair_afrom_num(fake, PW_EAP_TYPE, 0); + rad_assert(vp != NULL); + vp->vp_integer = t->default_method; + fr_pair_add(&fake->config, vp); + } + + } else { + /* + * Don't reject the request outright, + * as it's permitted to do EAP without + * user-name. + */ + RWDEBUG2("No EAP-Identity found to start EAP conversation"); + } + } /* else there WAS a t->username */ + + if (t->username) { + vp = fr_pair_list_copy(fake->packet, t->username); + fr_pair_add(&fake->packet->vps, vp); + fake->username = fr_pair_find_by_num(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY); + } + } /* else the request ALREADY had a User-Name */ + + /* + * Add the State attribute, too, if it exists. + */ + if (t->state) { + vp = fr_pair_list_copy(fake->packet, t->state); + if (vp) fr_pair_add(&fake->packet->vps, vp); + } + + /* + * If this is set, we copy SOME of the request attributes + * from outside of the tunnel to inside of the tunnel. + * + * We copy ONLY those attributes which do NOT already + * exist in the tunneled request. + */ + if (t->copy_request_to_tunnel) { + VALUE_PAIR *copy; + vp_cursor_t cursor; + + for (vp = fr_cursor_init(&cursor, &request->packet->vps); vp; vp = fr_cursor_next(&cursor)) { + /* + * The attribute is a server-side thingy, + * don't copy it. + */ + if ((vp->da->attr > 255) && + (vp->da->vendor == 0)) { + continue; + } + + /* + * The outside attribute is already in the + * tunnel, don't copy it. + * + * This works for BOTH attributes which + * are originally in the tunneled request, + * AND attributes which are copied there + * from below. + */ + if (fr_pair_find_by_da(fake->packet->vps, vp->da, TAG_ANY)) { + continue; + } + + /* + * Some attributes are handled specially. + */ + if (!vp->da->vendor) switch (vp->da->attr) { + /* + * NEVER copy Message-Authenticator, + * EAP-Message, or State. They're + * only for outside of the tunnel. + */ + case PW_USER_NAME: + case PW_USER_PASSWORD: + case PW_CHAP_PASSWORD: + case PW_CHAP_CHALLENGE: + case PW_PROXY_STATE: + case PW_MESSAGE_AUTHENTICATOR: + case PW_EAP_MESSAGE: + case PW_STATE: + continue; + + /* + * By default, copy it over. + */ + default: + break; + } + + /* + * Don't copy from the head, we've already + * checked it. + */ + copy = fr_pair_list_copy_by_num(fake->packet, vp, vp->da->attr, vp->da->vendor, TAG_ANY); + fr_pair_add(&fake->packet->vps, copy); + } + } + + if ((vp = fr_pair_find_by_num(request->config, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) { + fake->server = vp->vp_strvalue; + + } else if (t->virtual_server) { + fake->server = t->virtual_server; + + } /* else fake->server == request->server */ + + + if ((rad_debug_lvl > 0) && fr_log_fp) { + RDEBUG("Sending tunneled request"); + } + + /* + * Process channel binding. + */ + chbind = eap_chbind_vp2packet(fake, fake->packet->vps); + if (chbind) { + PW_CODE chbind_code; + CHBIND_REQ *req = talloc_zero(fake, CHBIND_REQ); + + RDEBUG("received chbind request"); + req->request = chbind; + if (fake->username) { + req->username = fake->username; + } else { + req->username = NULL; + } + chbind_code = chbind_process(request, req); + + /* encapsulate response here */ + if (req->response) { + RDEBUG("sending chbind response"); + fr_pair_add(&fake->reply->vps, + eap_chbind_packet2vp(fake->reply, req->response)); + } else { + RDEBUG("no chbind response"); + } + + /* clean up chbind req */ + talloc_free(req); + + if (chbind_code != PW_CODE_ACCESS_ACCEPT) { + return chbind_code; + } + } + + /* + * Call authentication recursively, which will + * do PAP, CHAP, MS-CHAP, etc. + */ + rad_virtual_server(fake); + + /* + * Decide what to do with the reply. + */ + switch (fake->reply->code) { + case 0: /* No reply code, must be proxied... */ +#ifdef WITH_PROXY + vp = fr_pair_find_by_num(fake->config, PW_PROXY_TO_REALM, 0, TAG_ANY); + if (vp) { + eap_tunnel_data_t *tunnel; + RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue); + + /* + * Tell the original request that it's going + * to be proxied. + */ + fr_pair_list_mcopy_by_num(request, &request->config, + &fake->config, + PW_PROXY_TO_REALM, 0, TAG_ANY); + + /* + * Seed the proxy packet with the + * tunneled request. + */ + rad_assert(!request->proxy); + request->proxy = talloc_steal(request, fake->packet); + memset(&request->proxy->src_ipaddr, 0, + sizeof(request->proxy->src_ipaddr)); + memset(&request->proxy->src_ipaddr, 0, + sizeof(request->proxy->src_ipaddr)); + request->proxy->src_port = 0; + request->proxy->dst_port = 0; + fake->packet = NULL; + rad_free(&fake->reply); + fake->reply = NULL; + + /* + * Set up the callbacks for the tunnel + */ + tunnel = talloc_zero(request, eap_tunnel_data_t); + tunnel->tls_session = tls_session; + tunnel->callback = eapttls_postproxy; + + /* + * Associate the callback with the request. + */ + code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_TUNNEL_CALLBACK, + tunnel, false); + rad_assert(code == 0); + + /* + * rlm_eap.c has taken care of associating + * the handler with the fake request. + * + * So we associate the fake request with + * this request. + */ + code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK, + fake, true); + rad_assert(code == 0); + fake = NULL; + + /* + * Didn't authenticate the packet, but + * we're proxying it. + */ + code = PW_CODE_STATUS_CLIENT; + + } else +#endif /* WITH_PROXY */ + { + RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.", + request->number); + code = PW_CODE_ACCESS_REJECT; + } + break; + + default: + /* + * Returns RLM_MODULE_FOO, and we want to return PW_FOO + */ + rcode = process_reply(handler, tls_session, request, fake->reply); + switch (rcode) { + case RLM_MODULE_REJECT: + code = PW_CODE_ACCESS_REJECT; + break; + + case RLM_MODULE_HANDLED: + code = PW_CODE_ACCESS_CHALLENGE; + break; + + case RLM_MODULE_OK: + code = PW_CODE_ACCESS_ACCEPT; + break; + + default: + code = PW_CODE_ACCESS_REJECT; + break; + } + break; + } + + talloc_free(fake); + + return code; +} |