src/modules/rlm_eap/types/rlm_eap_tls/rlm_eap_tls.c

   1 /*
   2  * rlm_eap_tls.c  contains the interfaces that are called from eap
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * Copyright 2001  hereUare Communications, Inc. <raghud@hereuare.com>
  21  * Copyright 2003  Alan DeKok <aland@freeradius.org>
  22  * Copyright 2006  The FreeRADIUS server project
  23  *
  24  */
  25
  26 RCSID("$Id$")
  27 USES_APPLE_DEPRECATED_API       /* OpenSSL API has been deprecated by Apple */
  28
  29 #ifdef HAVE_OPENSSL_RAND_H
  30 #include <openssl/rand.h>
  31 #endif
  32
  33 #ifdef HAVE_OPENSSL_EVP_H
  34 #include <openssl/evp.h>
  35 #endif
  36
  37 #include "rlm_eap_tls.h"
  38
  39 #ifdef HAVE_SYS_STAT_H
  40 #include <sys/stat.h>
  41 #endif
  42
  43 static CONF_PARSER module_config[] = {
  44         { "tls", PW_TYPE_STRING_PTR,
  45           offsetof(rlm_eap_tls_t, tls_conf_name), NULL, NULL },
  46
  47         { "virtual_server", PW_TYPE_STRING_PTR,
  48           offsetof(rlm_eap_tls_t, virtual_server), NULL, NULL },
  49
  50         { NULL, -1, 0, NULL, NULL }        /* end the list */
  51 };
  52
  53
  54 /*
  55  *      Attach the EAP-TLS module.
  56  */
  57 static int eaptls_attach(CONF_SECTION *cs, void **instance)
  58 {
  59         rlm_eap_tls_t           *inst;
  60
  61         /*
  62          *      Parse the config file & get all the configured values
  63          */
  64         *instance = inst = talloc_zero(cs, rlm_eap_tls_t);
  65         if (!inst) return -1;
  66
  67         if (cf_section_parse(cs, inst, module_config) < 0) {
  68                 return -1;
  69         }
  70
  71         inst->tls_conf = eaptls_conf_parse(cs, "tls");
  72
  73         if (!inst->tls_conf) {
  74                 ERROR("rlm_eap_tls: Failed initializing SSL context");
  75                 return -1;
  76         }
  77
  78         return 0;
  79 }
  80
  81
  82 /*
  83  *      Send an initial eap-tls request to the peer, using the libeap functions.
  84  */
  85 static int eaptls_initiate(void *type_arg, eap_handler_t *handler)
  86 {
  87         int             status;
  88         tls_session_t   *ssn;
  89         rlm_eap_tls_t   *inst;
  90         REQUEST         *request = handler->request;
  91
  92         inst = type_arg;
  93
  94         handler->tls = true;
  95         handler->finished = false;
  96
  97         /*
  98          *      EAP-TLS always requires a client certificate.
  99          */
 100         ssn = eaptls_session(inst->tls_conf, handler, true);
 101         if (!ssn) {
 102                 return 0;
 103         }
 104
 105         handler->opaque = ((void *)ssn);
 106         handler->free_opaque = session_free;
 107
 108         /*
 109          *      Set up type-specific information.
 110          */
 111         ssn->prf_label = "client EAP encryption";
 112
 113         /*
 114          *      TLS session initialization is over.  Now handle TLS
 115          *      related handshaking or application data.
 116          */
 117         status = eaptls_start(handler->eap_ds, ssn->peap_flag);
 118         RDEBUG2("Start returned %d", status);
 119         if (status == 0) {
 120                 return 0;
 121         }
 122
 123         /*
 124          *      The next stage to process the packet.
 125          */
 126         handler->stage = AUTHENTICATE;
 127
 128         return 1;
 129 }
 130
 131 /*
 132  *      Do authentication, by letting EAP-TLS do most of the work.
 133  */
 134 static int mod_authenticate(void *type_arg, eap_handler_t *handler)
 135 {
 136         fr_tls_status_t status;
 137         tls_session_t *tls_session = (tls_session_t *) handler->opaque;
 138         REQUEST *request = handler->request;
 139         rlm_eap_tls_t *inst;
 140
 141         inst = type_arg;
 142
 143         RDEBUG2("Authenticate");
 144
 145         status = eaptls_process(handler);
 146         RDEBUG2("eaptls_process returned %d\n", status);
 147         switch (status) {
 148                 /*
 149                  *      EAP-TLS handshake was successful, return an
 150                  *      EAP-TLS-Success packet here.
 151                  *
 152                  *      If a virtual server was configured, check that
 153                  *      it accepts the certificates, too.
 154                  */
 155         case FR_TLS_SUCCESS:
 156                 if (inst->virtual_server) {
 157                         VALUE_PAIR *vp;
 158                         REQUEST *fake;
 159
 160                         /* create a fake request */
 161                         fake = request_alloc_fake(request);
 162                         rad_assert(!fake->packet->vps);
 163
 164                         fake->packet->vps = paircopy(fake->packet, request->packet->vps);
 165
 166                         /* set the virtual server to use */
 167                         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) {
 168                                 fake->server = vp->vp_strvalue;
 169                         } else {
 170                                 fake->server = inst->virtual_server;
 171                         }
 172
 173                         RDEBUG("Processing EAP-TLS Certificate check:");
 174                         debug_pair_list(fake->packet->vps);
 175
 176                         RDEBUG("server %s {", fake->server);
 177
 178                         rad_virtual_server(fake);
 179
 180                         RDEBUG("} # server %s", fake->server);
 181
 182                         /* copy the reply vps back to our reply */
 183                         pairfilter(request->reply, &request->reply->vps,
 184                                   &fake->reply->vps, 0, 0, TAG_ANY);
 185
 186                         /* reject if virtual server didn't return accept */
 187                         if (fake->reply->code != PW_AUTHENTICATION_ACK) {
 188                                 RDEBUG2("Certificates were rejected by the virtual server");
 189                                 request_free(&fake);
 190                                 eaptls_fail(handler, 0);
 191                                 return 0;
 192                         }
 193
 194                         request_free(&fake);
 195                         /* success */
 196                 }
 197                 break;
 198
 199                 /*
 200                  *      The TLS code is still working on the TLS
 201                  *      exchange, and it's a valid TLS request.
 202                  *      do nothing.
 203                  */
 204         case FR_TLS_HANDLED:
 205                 return 1;
 206
 207                 /*
 208                  *      Handshake is done, proceed with decoding tunneled
 209                  *      data.
 210                  */
 211         case FR_TLS_OK:
 212                 RDEBUG2("Received unexpected tunneled data after successful handshake.");
 213 #ifndef NDEBUG
 214                 if ((debug_flag > 2) && fr_log_fp) {
 215                         unsigned int i;
 216                         unsigned int data_len;
 217                         unsigned char buffer[1024];
 218
 219                         data_len = (tls_session->record_minus)(&tls_session->dirty_in,
 220                                                 buffer, sizeof(buffer));
 221                         DEBUG("  Tunneled data (%u bytes)", data_len);
 222                         for (i = 0; i < data_len; i++) {
 223                                 if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "  %x: ", i);
 224                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 225
 226                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 227                         }
 228                         fprintf(fr_log_fp, "\n");
 229                 }
 230 #endif
 231
 232                 eaptls_fail(handler, 0);
 233                 return 0;
 234                 break;
 235
 236                 /*
 237                  *      Anything else: fail.
 238                  *
 239                  *      Also, remove the session from the cache so that
 240                  *      the client can't re-use it.
 241                  */
 242         default:
 243                 tls_fail(tls_session);
 244
 245                 return 0;
 246         }
 247
 248         /*
 249          *      Success: Automatically return MPPE keys.
 250          */
 251         return eaptls_success(handler, 0);
 252 }
 253
 254 /*
 255  *      The module name should be the only globally exported symbol.
 256  *      That is, everything else should be 'static'.
 257  */
 258 rlm_eap_module_t rlm_eap_tls = {
 259         "eap_tls",
 260         eaptls_attach,                  /* attach */
 261         eaptls_initiate,                /* Start the initial request */
 262         NULL,                           /* authorization */
 263         mod_authenticate,               /* authentication */
 264         NULL                            /* detach */
 265 };