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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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},
67 { NULL, -1, 0, NULL, NULL } /* end the list */
72 * TODO: Check for the type of key exchange * like conf->dh_key
74 static int load_dh_params(SSL_CTX *ctx, char *file)
79 if ((bio = BIO_new_file(file, "r")) == NULL) {
80 radlog(L_ERR, "rlm_eap_tls: Unable to open DH file - %s", file);
84 dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
86 if (SSL_CTX_set_tmp_dh(ctx, dh) < 0) {
87 radlog(L_ERR, "rlm_eap_tls: Unable to set DH parameters");
97 * Generte ephemeral RSA keys.
99 static int generate_eph_rsa_key(SSL_CTX *ctx)
103 rsa = RSA_generate_key(512, RSA_F4, NULL, NULL);
105 if (!SSL_CTX_set_tmp_rsa(ctx, rsa)) {
106 radlog(L_ERR, "rlm_eap_tls: Couldn't set RSA key");
116 * Create Global context SSL and use it in every new session
118 * - Load the trusted CAs
119 * - Load the Private key & the certificate
120 * - Set the Context options & Verify options
122 static SSL_CTX *init_tls_ctx(EAP_TLS_CONF *conf)
126 X509_STORE *certstore;
132 * Add all the default ciphers and message digests
133 * Create our context.
136 SSL_load_error_strings();
138 meth = TLSv1_method();
139 ctx = SSL_CTX_new(meth);
142 * Identify the type of certificates that needs to be loaded
144 if (conf->file_type) {
145 type = SSL_FILETYPE_PEM;
147 type = SSL_FILETYPE_ASN1;
151 * Set the password to load private key
153 if (conf->private_key_password) {
154 SSL_CTX_set_default_passwd_cb_userdata(ctx, conf->private_key_password);
155 SSL_CTX_set_default_passwd_cb(ctx, cbtls_password);
159 * Load our keys and certificates
161 * If certificates are of type PEM then we can make use
162 * of cert chain authentication using openssl api call
163 * SSL_CTX_use_certificate_chain_file. Please see how
164 * the cert chain needs to be given in PEM from
167 if (type == SSL_FILETYPE_PEM) {
168 radlog(L_INFO, "rlm_eap_tls: Loading the certificate file as a chain");
169 if (!(SSL_CTX_use_certificate_chain_file(ctx, conf->certificate_file))) {
170 ERR_print_errors_fp(stderr);
171 radlog(L_ERR, "rlm_eap_tls: Error reading certificate file");
175 } else if (!(SSL_CTX_use_certificate_file(ctx, conf->certificate_file, type))) {
176 ERR_print_errors_fp(stderr);
177 radlog(L_ERR, "rlm_eap_tls: Error reading certificate file");
182 /* Load the CAs we trust */
183 if (!SSL_CTX_load_verify_locations(ctx, conf->ca_file, conf->ca_path)) {
184 ERR_print_errors_fp(stderr);
185 radlog(L_ERR, "rlm_eap_tls: Error reading Trusted root CA list");
188 SSL_CTX_set_client_CA_list(ctx, SSL_load_client_CA_file(conf->ca_file));
190 if (!(SSL_CTX_use_PrivateKey_file(ctx, conf->private_key_file, type))) {
191 ERR_print_errors_fp(stderr);
192 radlog(L_ERR, "rlm_eap_tls: Error reading private key file");
197 * Check if the loaded private key is the right one
199 if (!SSL_CTX_check_private_key(ctx)) {
200 radlog(L_ERR, "rlm_eap_tls: Private key does not match the certificate public key");
207 ctx_options |= SSL_OP_NO_SSLv2;
208 ctx_options |= SSL_OP_NO_SSLv3;
211 * SSL_OP_SINGLE_DH_USE must be used in order to prevent
212 * small subgroup attacks and forward secrecy. Always
215 * SSL_OP_SINGLE_DH_USE has an impact on the computer
216 * time needed during negotiation, but it is not very
219 ctx_options |= SSL_OP_SINGLE_DH_USE;
220 SSL_CTX_set_options(ctx, ctx_options);
223 * TODO: Set the RSA & DH
224 * SSL_CTX_set_tmp_rsa_callback(ctx, cbtls_rsa);
225 * SSL_CTX_set_tmp_dh_callback(ctx, cbtls_dh);
229 * set the message callback to identify the type of
230 * message. For every new session, there can be a
231 * different callback argument.
233 * SSL_CTX_set_msg_callback(ctx, cbtls_msg);
236 /* Set Info callback */
237 SSL_CTX_set_info_callback(ctx, cbtls_info);
240 * Check the certificates for revocation.
242 #ifdef X509_V_FLAG_CRL_CHECK
243 if (conf->check_crl) {
244 certstore = SSL_CTX_get_cert_store(ctx);
245 if (certstore == NULL) {
246 ERR_print_errors_fp(stderr);
247 radlog(L_ERR, "rlm_eap_tls: Error reading Certificate Store");
250 X509_STORE_set_flags(certstore, X509_V_FLAG_CRL_CHECK);
256 * Always verify the peer certificate
258 verify_mode |= SSL_VERIFY_PEER;
259 verify_mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
260 verify_mode |= SSL_VERIFY_CLIENT_ONCE;
261 SSL_CTX_set_verify(ctx, verify_mode, cbtls_verify);
263 if (conf->verify_depth) {
264 SSL_CTX_set_verify_depth(ctx, conf->verify_depth);
267 /* Load randomness */
268 if (!(RAND_load_file(conf->random_file, 1024*1024))) {
269 ERR_print_errors_fp(stderr);
270 radlog(L_ERR, "rlm_eap_tls: Error loading randomness");
279 * Detach the EAP-TLS module.
281 static int eaptls_detach(void *arg)
286 inst = (eap_tls_t *) arg;
290 if (conf->dh_file) free(conf->dh_file);
291 conf->dh_file = NULL;
292 if (conf->certificate_file) free(conf->certificate_file);
293 conf->certificate_file = NULL;
294 if (conf->private_key_file) free(conf->private_key_file);
295 conf->private_key_file = NULL;
296 if (conf->private_key_password) free(conf->private_key_password);
297 conf->private_key_password = NULL;
298 if (conf->random_file) free(conf->random_file);
299 conf->random_file = NULL;
305 if (inst->ctx) SSL_CTX_free(inst->ctx);
315 * Attach the EAP-TLS module.
317 static int eaptls_attach(CONF_SECTION *cs, void **instance)
322 /* Store all these values in the data structure for later references */
323 inst = (eap_tls_t *)malloc(sizeof(*inst));
325 radlog(L_ERR, "rlm_eap_tls: out of memory");
328 memset(inst, 0, sizeof(*inst));
331 * Parse the config file & get all the configured values
333 conf = (EAP_TLS_CONF *)malloc(sizeof(*conf));
335 radlog(L_ERR, "rlm_eap_tls: out of memory");
338 memset(conf, 0, sizeof(*conf));
341 if (cf_section_parse(cs, conf, module_config) < 0) {
350 inst->ctx = init_tls_ctx(conf);
351 if (inst->ctx == NULL) {
356 if (load_dh_params(inst->ctx, conf->dh_file) < 0) {
360 if (generate_eph_rsa_key(inst->ctx) < 0) {
372 * Send an initial eap-tls request to the peer.
374 * Frame eap reply packet.
375 * len = header + type + tls_typedata
376 * tls_typedata = flags(Start (S) bit set, and no data)
378 * Once having received the peer's Identity, the EAP server MUST
379 * respond with an EAP-TLS/Start packet, which is an
380 * EAP-Request packet with EAP-Type=EAP-TLS, the Start (S) bit
381 * set, and no data. The EAP-TLS conversation will then begin,
382 * with the peer sending an EAP-Response packet with
383 * EAP-Type = EAP-TLS. The data field of that packet will
386 * Fragment length is Framed-MTU - 4.
388 * http://mail.frascone.com/pipermail/public/eap/2003-July/001426.html
390 static int eaptls_initiate(void *type_arg, EAP_HANDLER *handler)
396 int client_cert = TRUE;
398 inst = (eap_tls_t *)type_arg;
401 * If we're TTLS or PEAP, then do NOT require a client
404 * FIXME: This should be more configurable.
406 if (handler->eap_type != PW_EAP_TLS) {
407 vp = pairfind(handler->request->config_items,
408 PW_EAP_TLS_REQUIRE_CLIENT_CERT);
412 client_cert = vp->lvalue;
417 * Every new session is started only from EAP-TLS-START.
418 * Before Sending EAP-TLS-START, open a new SSL session.
419 * Create all the required data structures & store them
420 * in Opaque. So that we can use these data structures
421 * when we get the response
423 ssn = eaptls_new_session(inst->ctx, client_cert);
429 * Create a structure for all the items required to be
430 * verified for each client and set that as opaque data
433 * NOTE: If we want to set each item sepearately then
434 * this index should be global.
436 SSL_set_ex_data(ssn->ssl, 0, (void *)handler);
437 SSL_set_ex_data(ssn->ssl, 1, (void *)inst->conf);
439 ssn->length_flag = inst->conf->include_length;
442 * We set a default fragment size, unless the Framed-MTU
443 * tells us it's too big.
445 ssn->offset = inst->conf->fragment_size;
446 vp = pairfind(handler->request->packet->vps, PW_FRAMED_MTU);
447 if (vp && ((vp->lvalue - 4) < ssn->offset)) {
448 ssn->offset = vp->lvalue - 4;
451 handler->opaque = ((void *)ssn);
452 handler->free_opaque = session_free;
454 DEBUG2(" rlm_eap_tls: Initiate");
457 * PEAP-specific breakage.
459 if (handler->eap_type == PW_EAP_PEAP) {
461 * As it is a poorly designed protocol, PEAP uses
462 * bits in the TLS header to indicate PEAP
463 * version numbers. For now, we only support
464 * PEAP version 0, so it doesn't matter too much.
465 * However, if we support later versions of PEAP,
466 * we will need this flag to indicate which
467 * version we're currently dealing with.
469 ssn->peap_flag = 0x00;
472 * PEAP version 0 requires 'include_length = no',
473 * so rather than hoping the user figures it out,
476 ssn->length_flag = 0;
480 * TLS session initialization is over. Now handle TLS
481 * related handshaking or application data.
483 status = eaptls_start(handler->eap_ds, ssn->peap_flag);
484 DEBUG2(" rlm_eap_tls: Start returned %d", status);
489 * The next stage to process the packet.
491 handler->stage = AUTHENTICATE;
497 * Do authentication, by letting EAP-TLS do most of the work.
499 static int eaptls_authenticate(void *arg UNUSED, EAP_HANDLER *handler)
501 eaptls_status_t status;
502 tls_session_t *tls_session = (tls_session_t *) handler->opaque;
504 DEBUG2(" rlm_eap_tls: Authenticate");
506 status = eaptls_process(handler);
507 DEBUG2(" eaptls_process returned %d\n", status);
510 * EAP-TLS handshake was successful, return an
511 * EAP-TLS-Success packet here.
517 * The TLS code is still working on the TLS
518 * exchange, and it's a valid TLS request.
525 * Handshake is done, proceed with decoding tunneled
529 DEBUG2(" rlm_eap_tls: Received unexpected tunneled data after successful handshake.");
531 if (debug_flag > 2) {
533 unsigned int data_len;
534 unsigned char buffer[1024];
536 data_len = (tls_session->record_minus)(&tls_session->dirty_in,
537 buffer, sizeof(buffer));
538 log_debug(" Tunneled data (%u bytes)\n", data_len);
539 for (i = 0; i < data_len; i++) {
540 if ((i & 0x0f) == 0x00) printf(" %x: ", i);
541 if ((i & 0x0f) == 0x0f) printf("\n");
543 printf("%02x ", buffer[i]);
549 eaptls_fail(handler->eap_ds, 0);
554 * Anything else: fail.
561 * Success: Return MPPE keys.
563 eaptls_success(handler->eap_ds, 0);
564 eaptls_gen_mppe_keys(&handler->request->reply->vps,
566 "client EAP encryption");
571 * The module name should be the only globally exported symbol.
572 * That is, everything else should be 'static'.
574 EAP_TYPE rlm_eap_tls = {
576 eaptls_attach, /* attach */
577 eaptls_initiate, /* Start the initial request */
578 NULL, /* authorization */
579 eaptls_authenticate, /* authentication */
580 eaptls_detach /* detach */