2 * rlm_eap_tls.c contains the interfaces that are called from eap
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.
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.
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
20 * Copyright 2001 hereUare Communications, Inc. <raghud@hereuare.com>
21 * Copyright 2003 Alan DeKok <aland@freeradius.org>
24 #include <freeradius-devel/autoconf.h>
27 #ifdef HAVE_OPENSSL_RAND_H
28 #include <openssl/rand.h>
31 static CONF_PARSER module_config[] = {
32 { "rsa_key_exchange", PW_TYPE_BOOLEAN,
33 offsetof(EAP_TLS_CONF, rsa_key), NULL, "no" },
34 { "dh_key_exchange", PW_TYPE_BOOLEAN,
35 offsetof(EAP_TLS_CONF, dh_key), NULL, "yes" },
36 { "rsa_key_length", PW_TYPE_INTEGER,
37 offsetof(EAP_TLS_CONF, rsa_key_length), NULL, "512" },
38 { "dh_key_length", PW_TYPE_INTEGER,
39 offsetof(EAP_TLS_CONF, dh_key_length), NULL, "512" },
40 { "verify_depth", PW_TYPE_INTEGER,
41 offsetof(EAP_TLS_CONF, verify_depth), NULL, "0" },
42 { "CA_path", PW_TYPE_FILENAME,
43 offsetof(EAP_TLS_CONF, ca_path), NULL, NULL },
44 { "pem_file_type", PW_TYPE_BOOLEAN,
45 offsetof(EAP_TLS_CONF, file_type), NULL, "yes" },
46 { "private_key_file", PW_TYPE_FILENAME,
47 offsetof(EAP_TLS_CONF, private_key_file), NULL, NULL },
48 { "certificate_file", PW_TYPE_FILENAME,
49 offsetof(EAP_TLS_CONF, certificate_file), NULL, NULL },
50 { "CA_file", PW_TYPE_FILENAME,
51 offsetof(EAP_TLS_CONF, ca_file), NULL, NULL },
52 { "private_key_password", PW_TYPE_STRING_PTR,
53 offsetof(EAP_TLS_CONF, private_key_password), NULL, NULL },
54 { "dh_file", PW_TYPE_STRING_PTR,
55 offsetof(EAP_TLS_CONF, dh_file), NULL, NULL },
56 { "random_file", PW_TYPE_STRING_PTR,
57 offsetof(EAP_TLS_CONF, random_file), NULL, NULL },
58 { "fragment_size", PW_TYPE_INTEGER,
59 offsetof(EAP_TLS_CONF, fragment_size), NULL, "1024" },
60 { "include_length", PW_TYPE_BOOLEAN,
61 offsetof(EAP_TLS_CONF, include_length), NULL, "yes" },
62 { "check_crl", PW_TYPE_BOOLEAN,
63 offsetof(EAP_TLS_CONF, check_crl), NULL, "no"},
64 { "check_cert_cn", PW_TYPE_STRING_PTR,
65 offsetof(EAP_TLS_CONF, check_cert_cn), NULL, NULL},
66 { "cipher_list", PW_TYPE_STRING_PTR,
67 offsetof(EAP_TLS_CONF, cipher_list), NULL, NULL},
69 { NULL, -1, 0, NULL, NULL } /* end the list */
74 * TODO: Check for the type of key exchange * like conf->dh_key
76 static int load_dh_params(SSL_CTX *ctx, char *file)
81 if ((bio = BIO_new_file(file, "r")) == NULL) {
82 radlog(L_ERR, "rlm_eap_tls: Unable to open DH file - %s", file);
86 dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
88 if (SSL_CTX_set_tmp_dh(ctx, dh) < 0) {
89 radlog(L_ERR, "rlm_eap_tls: Unable to set DH parameters");
99 * Generte ephemeral RSA keys.
101 static int generate_eph_rsa_key(SSL_CTX *ctx)
105 rsa = RSA_generate_key(512, RSA_F4, NULL, NULL);
107 if (!SSL_CTX_set_tmp_rsa(ctx, rsa)) {
108 radlog(L_ERR, "rlm_eap_tls: Couldn't set RSA key");
118 * Create Global context SSL and use it in every new session
120 * - Load the trusted CAs
121 * - Load the Private key & the certificate
122 * - Set the Context options & Verify options
124 static SSL_CTX *init_tls_ctx(EAP_TLS_CONF *conf)
128 X509_STORE *certstore;
134 * Add all the default ciphers and message digests
135 * Create our context.
138 SSL_load_error_strings();
140 meth = TLSv1_method();
141 ctx = SSL_CTX_new(meth);
144 * Identify the type of certificates that needs to be loaded
146 if (conf->file_type) {
147 type = SSL_FILETYPE_PEM;
149 type = SSL_FILETYPE_ASN1;
153 * Set the password to load private key
155 if (conf->private_key_password) {
156 SSL_CTX_set_default_passwd_cb_userdata(ctx, conf->private_key_password);
157 SSL_CTX_set_default_passwd_cb(ctx, cbtls_password);
161 * Load our keys and certificates
163 * If certificates are of type PEM then we can make use
164 * of cert chain authentication using openssl api call
165 * SSL_CTX_use_certificate_chain_file. Please see how
166 * the cert chain needs to be given in PEM from
169 if (type == SSL_FILETYPE_PEM) {
170 radlog(L_INFO, "rlm_eap_tls: Loading the certificate file as a chain");
171 if (!(SSL_CTX_use_certificate_chain_file(ctx, conf->certificate_file))) {
172 ERR_print_errors_fp(stderr);
173 radlog(L_ERR, "rlm_eap_tls: Error reading certificate file");
177 } else if (!(SSL_CTX_use_certificate_file(ctx, conf->certificate_file, type))) {
178 ERR_print_errors_fp(stderr);
179 radlog(L_ERR, "rlm_eap_tls: Error reading certificate file");
184 /* Load the CAs we trust */
185 if (!SSL_CTX_load_verify_locations(ctx, conf->ca_file, conf->ca_path)) {
186 ERR_print_errors_fp(stderr);
187 radlog(L_ERR, "rlm_eap_tls: Error reading Trusted root CA list");
190 SSL_CTX_set_client_CA_list(ctx, SSL_load_client_CA_file(conf->ca_file));
193 if (!(SSL_CTX_use_PrivateKey_file(ctx, conf->private_key_file, type))) {
194 ERR_print_errors_fp(stderr);
195 radlog(L_ERR, "rlm_eap_tls: Error reading private key file");
200 * Check if the loaded private key is the right one
202 if (!SSL_CTX_check_private_key(ctx)) {
203 radlog(L_ERR, "rlm_eap_tls: Private key does not match the certificate public key");
210 ctx_options |= SSL_OP_NO_SSLv2;
211 ctx_options |= SSL_OP_NO_SSLv3;
214 * SSL_OP_SINGLE_DH_USE must be used in order to prevent
215 * small subgroup attacks and forward secrecy. Always
218 * SSL_OP_SINGLE_DH_USE has an impact on the computer
219 * time needed during negotiation, but it is not very
222 ctx_options |= SSL_OP_SINGLE_DH_USE;
223 SSL_CTX_set_options(ctx, ctx_options);
226 * TODO: Set the RSA & DH
227 * SSL_CTX_set_tmp_rsa_callback(ctx, cbtls_rsa);
228 * SSL_CTX_set_tmp_dh_callback(ctx, cbtls_dh);
232 * set the message callback to identify the type of
233 * message. For every new session, there can be a
234 * different callback argument.
236 * SSL_CTX_set_msg_callback(ctx, cbtls_msg);
239 /* Set Info callback */
240 SSL_CTX_set_info_callback(ctx, cbtls_info);
243 * Check the certificates for revocation.
245 #ifdef X509_V_FLAG_CRL_CHECK
246 if (conf->check_crl) {
247 certstore = SSL_CTX_get_cert_store(ctx);
248 if (certstore == NULL) {
249 ERR_print_errors_fp(stderr);
250 radlog(L_ERR, "rlm_eap_tls: Error reading Certificate Store");
253 X509_STORE_set_flags(certstore, X509_V_FLAG_CRL_CHECK);
259 * Always verify the peer certificate
261 verify_mode |= SSL_VERIFY_PEER;
262 verify_mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
263 verify_mode |= SSL_VERIFY_CLIENT_ONCE;
264 SSL_CTX_set_verify(ctx, verify_mode, cbtls_verify);
266 if (conf->verify_depth) {
267 SSL_CTX_set_verify_depth(ctx, conf->verify_depth);
270 /* Load randomness */
271 if (!(RAND_load_file(conf->random_file, 1024*1024))) {
272 ERR_print_errors_fp(stderr);
273 radlog(L_ERR, "rlm_eap_tls: Error loading randomness");
278 * Set the cipher list if we were told to
280 if (conf->cipher_list) {
281 if (!SSL_CTX_set_cipher_list(ctx, conf->cipher_list)) {
282 radlog(L_ERR, "rlm_eap_tls: Error setting cipher list");
291 * Detach the EAP-TLS module.
293 static int eaptls_detach(void *arg)
298 inst = (eap_tls_t *) arg;
302 if (conf->dh_file) free(conf->dh_file);
303 conf->dh_file = NULL;
304 if (conf->certificate_file) free(conf->certificate_file);
305 conf->certificate_file = NULL;
306 if (conf->private_key_file) free(conf->private_key_file);
307 conf->private_key_file = NULL;
308 if (conf->private_key_password) free(conf->private_key_password);
309 conf->private_key_password = NULL;
310 if (conf->random_file) free(conf->random_file);
311 conf->random_file = NULL;
317 if (inst->ctx) SSL_CTX_free(inst->ctx);
327 * Attach the EAP-TLS module.
329 static int eaptls_attach(CONF_SECTION *cs, void **instance)
334 /* Store all these values in the data structure for later references */
335 inst = (eap_tls_t *)malloc(sizeof(*inst));
337 radlog(L_ERR, "rlm_eap_tls: out of memory");
340 memset(inst, 0, sizeof(*inst));
343 * Parse the config file & get all the configured values
345 conf = (EAP_TLS_CONF *)malloc(sizeof(*conf));
347 radlog(L_ERR, "rlm_eap_tls: out of memory");
350 memset(conf, 0, sizeof(*conf));
353 if (cf_section_parse(cs, conf, module_config) < 0) {
362 inst->ctx = init_tls_ctx(conf);
363 if (inst->ctx == NULL) {
368 if (load_dh_params(inst->ctx, conf->dh_file) < 0) {
372 if (generate_eph_rsa_key(inst->ctx) < 0) {
384 * Send an initial eap-tls request to the peer.
386 * Frame eap reply packet.
387 * len = header + type + tls_typedata
388 * tls_typedata = flags(Start (S) bit set, and no data)
390 * Once having received the peer's Identity, the EAP server MUST
391 * respond with an EAP-TLS/Start packet, which is an
392 * EAP-Request packet with EAP-Type=EAP-TLS, the Start (S) bit
393 * set, and no data. The EAP-TLS conversation will then begin,
394 * with the peer sending an EAP-Response packet with
395 * EAP-Type = EAP-TLS. The data field of that packet will
398 * Fragment length is Framed-MTU - 4.
400 * http://mail.frascone.com/pipermail/public/eap/2003-July/001426.html
402 static int eaptls_initiate(void *type_arg, EAP_HANDLER *handler)
408 int client_cert = TRUE;
410 inst = (eap_tls_t *)type_arg;
413 * If we're TTLS or PEAP, then do NOT require a client
416 * FIXME: This should be more configurable.
418 if (handler->eap_type != PW_EAP_TLS) {
419 vp = pairfind(handler->request->config_items,
420 PW_EAP_TLS_REQUIRE_CLIENT_CERT);
424 client_cert = vp->lvalue;
429 * Every new session is started only from EAP-TLS-START.
430 * Before Sending EAP-TLS-START, open a new SSL session.
431 * Create all the required data structures & store them
432 * in Opaque. So that we can use these data structures
433 * when we get the response
435 ssn = eaptls_new_session(inst->ctx, client_cert);
441 * Create a structure for all the items required to be
442 * verified for each client and set that as opaque data
445 * NOTE: If we want to set each item sepearately then
446 * this index should be global.
448 SSL_set_ex_data(ssn->ssl, 0, (void *)handler);
449 SSL_set_ex_data(ssn->ssl, 1, (void *)inst->conf);
451 ssn->length_flag = inst->conf->include_length;
454 * We set a default fragment size, unless the Framed-MTU
455 * tells us it's too big.
457 ssn->offset = inst->conf->fragment_size;
458 vp = pairfind(handler->request->packet->vps, PW_FRAMED_MTU);
459 if (vp && ((vp->lvalue - 4) < ssn->offset)) {
460 ssn->offset = vp->lvalue - 4;
463 handler->opaque = ((void *)ssn);
464 handler->free_opaque = session_free;
466 DEBUG2(" rlm_eap_tls: Initiate");
469 * PEAP-specific breakage.
471 if (handler->eap_type == PW_EAP_PEAP) {
473 * As it is a poorly designed protocol, PEAP uses
474 * bits in the TLS header to indicate PEAP
475 * version numbers. For now, we only support
476 * PEAP version 0, so it doesn't matter too much.
477 * However, if we support later versions of PEAP,
478 * we will need this flag to indicate which
479 * version we're currently dealing with.
481 ssn->peap_flag = 0x00;
484 * PEAP version 0 requires 'include_length = no',
485 * so rather than hoping the user figures it out,
488 ssn->length_flag = 0;
492 * TLS session initialization is over. Now handle TLS
493 * related handshaking or application data.
495 status = eaptls_start(handler->eap_ds, ssn->peap_flag);
496 DEBUG2(" rlm_eap_tls: Start returned %d", status);
501 * The next stage to process the packet.
503 handler->stage = AUTHENTICATE;
509 * Do authentication, by letting EAP-TLS do most of the work.
511 static int eaptls_authenticate(void *arg UNUSED, EAP_HANDLER *handler)
513 eaptls_status_t status;
514 tls_session_t *tls_session = (tls_session_t *) handler->opaque;
516 DEBUG2(" rlm_eap_tls: Authenticate");
518 status = eaptls_process(handler);
519 DEBUG2(" eaptls_process returned %d\n", status);
522 * EAP-TLS handshake was successful, return an
523 * EAP-TLS-Success packet here.
529 * The TLS code is still working on the TLS
530 * exchange, and it's a valid TLS request.
537 * Handshake is done, proceed with decoding tunneled
541 DEBUG2(" rlm_eap_tls: Received unexpected tunneled data after successful handshake.");
543 if (debug_flag > 2) {
545 unsigned int data_len;
546 unsigned char buffer[1024];
548 data_len = (tls_session->record_minus)(&tls_session->dirty_in,
549 buffer, sizeof(buffer));
550 log_debug(" Tunneled data (%u bytes)\n", data_len);
551 for (i = 0; i < data_len; i++) {
552 if ((i & 0x0f) == 0x00) printf(" %x: ", i);
553 if ((i & 0x0f) == 0x0f) printf("\n");
555 printf("%02x ", buffer[i]);
561 eaptls_fail(handler->eap_ds, 0);
566 * Anything else: fail.
573 * Success: Return MPPE keys.
575 eaptls_success(handler->eap_ds, 0);
576 eaptls_gen_mppe_keys(&handler->request->reply->vps,
578 "client EAP encryption");
583 * The module name should be the only globally exported symbol.
584 * That is, everything else should be 'static'.
586 EAP_TYPE rlm_eap_tls = {
588 eaptls_attach, /* attach */
589 eaptls_initiate, /* Start the initial request */
590 NULL, /* authorization */
591 eaptls_authenticate, /* authentication */
592 eaptls_detach /* detach */