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>
22 * Copyright 2006 The FreeRADIUS server project
26 #include <freeradius-devel/ident.h>
29 #include <freeradius-devel/autoconf.h>
31 #ifdef HAVE_OPENSSL_RAND_H
32 #include <openssl/rand.h>
35 #ifdef HAVE_OPENSSL_EVP_H
36 #include <openssl/evp.h>
39 #include "rlm_eap_tls.h"
42 #ifdef HAVE_SYS_STAT_H
46 static CONF_PARSER cache_config[] = {
47 { "enable", PW_TYPE_BOOLEAN,
48 offsetof(EAP_TLS_CONF, session_cache_enable), NULL, "no" },
49 { "lifetime", PW_TYPE_INTEGER,
50 offsetof(EAP_TLS_CONF, session_timeout), NULL, "24" },
51 { "max_entries", PW_TYPE_INTEGER,
52 offsetof(EAP_TLS_CONF, session_cache_size), NULL, "255" },
53 { "name", PW_TYPE_STRING_PTR,
54 offsetof(EAP_TLS_CONF, session_id_name), NULL, NULL},
55 { NULL, -1, 0, NULL, NULL } /* end the list */
58 static CONF_PARSER verify_config[] = {
59 { "tmpdir", PW_TYPE_STRING_PTR,
60 offsetof(EAP_TLS_CONF, verify_tmp_dir), NULL, NULL},
61 { "client", PW_TYPE_STRING_PTR,
62 offsetof(EAP_TLS_CONF, verify_client_cert_cmd), NULL, NULL},
63 { NULL, -1, 0, NULL, NULL } /* end the list */
66 static CONF_PARSER module_config[] = {
67 { "rsa_key_exchange", PW_TYPE_BOOLEAN,
68 offsetof(EAP_TLS_CONF, rsa_key), NULL, "no" },
69 { "dh_key_exchange", PW_TYPE_BOOLEAN,
70 offsetof(EAP_TLS_CONF, dh_key), NULL, "yes" },
71 { "rsa_key_length", PW_TYPE_INTEGER,
72 offsetof(EAP_TLS_CONF, rsa_key_length), NULL, "512" },
73 { "dh_key_length", PW_TYPE_INTEGER,
74 offsetof(EAP_TLS_CONF, dh_key_length), NULL, "512" },
75 { "verify_depth", PW_TYPE_INTEGER,
76 offsetof(EAP_TLS_CONF, verify_depth), NULL, "0" },
77 { "CA_path", PW_TYPE_FILENAME,
78 offsetof(EAP_TLS_CONF, ca_path), NULL, NULL },
79 { "pem_file_type", PW_TYPE_BOOLEAN,
80 offsetof(EAP_TLS_CONF, file_type), NULL, "yes" },
81 { "private_key_file", PW_TYPE_FILENAME,
82 offsetof(EAP_TLS_CONF, private_key_file), NULL, NULL },
83 { "certificate_file", PW_TYPE_FILENAME,
84 offsetof(EAP_TLS_CONF, certificate_file), NULL, NULL },
85 { "CA_file", PW_TYPE_FILENAME,
86 offsetof(EAP_TLS_CONF, ca_file), NULL, NULL },
87 { "private_key_password", PW_TYPE_STRING_PTR,
88 offsetof(EAP_TLS_CONF, private_key_password), NULL, NULL },
89 { "dh_file", PW_TYPE_STRING_PTR,
90 offsetof(EAP_TLS_CONF, dh_file), NULL, NULL },
91 { "random_file", PW_TYPE_STRING_PTR,
92 offsetof(EAP_TLS_CONF, random_file), NULL, NULL },
93 { "fragment_size", PW_TYPE_INTEGER,
94 offsetof(EAP_TLS_CONF, fragment_size), NULL, "1024" },
95 { "include_length", PW_TYPE_BOOLEAN,
96 offsetof(EAP_TLS_CONF, include_length), NULL, "yes" },
97 { "check_crl", PW_TYPE_BOOLEAN,
98 offsetof(EAP_TLS_CONF, check_crl), NULL, "no"},
99 { "check_cert_cn", PW_TYPE_STRING_PTR,
100 offsetof(EAP_TLS_CONF, check_cert_cn), NULL, NULL},
101 { "cipher_list", PW_TYPE_STRING_PTR,
102 offsetof(EAP_TLS_CONF, cipher_list), NULL, NULL},
103 { "check_cert_issuer", PW_TYPE_STRING_PTR,
104 offsetof(EAP_TLS_CONF, check_cert_issuer), NULL, NULL},
105 { "make_cert_command", PW_TYPE_STRING_PTR,
106 offsetof(EAP_TLS_CONF, make_cert_command), NULL, NULL},
108 { "cache", PW_TYPE_SUBSECTION, 0, NULL, (const void *) cache_config },
110 { "verify", PW_TYPE_SUBSECTION, 0, NULL, (const void *) verify_config },
112 { NULL, -1, 0, NULL, NULL } /* end the list */
117 * TODO: Check for the type of key exchange * like conf->dh_key
119 static int load_dh_params(SSL_CTX *ctx, char *file)
124 if ((bio = BIO_new_file(file, "r")) == NULL) {
125 radlog(L_ERR, "rlm_eap_tls: Unable to open DH file - %s", file);
129 dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
132 DEBUG2("WARNING: rlm_eap_tls: Unable to set DH parameters. DH cipher suites may not work!");
133 DEBUG2("WARNING: Fix this by running the OpenSSL command listed in eap.conf");
137 if (SSL_CTX_set_tmp_dh(ctx, dh) < 0) {
138 radlog(L_ERR, "rlm_eap_tls: Unable to set DH parameters");
149 * Generate ephemeral RSA keys.
151 static int generate_eph_rsa_key(SSL_CTX *ctx)
155 rsa = RSA_generate_key(512, RSA_F4, NULL, NULL);
157 if (!SSL_CTX_set_tmp_rsa(ctx, rsa)) {
158 radlog(L_ERR, "rlm_eap_tls: Couldn't set ephemeral RSA key");
168 * These functions don't do anything other than print debugging
171 * FIXME: Write sessions to some long-term storage, so that
172 * session resumption can still occur after the server
175 #define MAX_SESSION_SIZE (256)
177 static void cbtls_remove_session(UNUSED SSL_CTX *ctx, SSL_SESSION *sess)
180 char buffer[2 * MAX_SESSION_SIZE + 1];
182 size = sess->session_id_length;
183 if (size > MAX_SESSION_SIZE) size = MAX_SESSION_SIZE;
185 fr_bin2hex(sess->session_id, buffer, size);
187 DEBUG2(" SSL: Removing session %s from the cache", buffer);
188 SSL_SESSION_free(sess);
193 static int cbtls_new_session(UNUSED SSL *s, SSL_SESSION *sess)
196 char buffer[2 * MAX_SESSION_SIZE + 1];
198 size = sess->session_id_length;
199 if (size > MAX_SESSION_SIZE) size = MAX_SESSION_SIZE;
201 fr_bin2hex(sess->session_id, buffer, size);
203 DEBUG2(" SSL: adding session %s to cache", buffer);
208 static SSL_SESSION *cbtls_get_session(UNUSED SSL *s,
209 unsigned char *data, int len,
213 char buffer[2 * MAX_SESSION_SIZE + 1];
216 if (size > MAX_SESSION_SIZE) size = MAX_SESSION_SIZE;
218 fr_bin2hex(data, buffer, size);
220 DEBUG2(" SSL: Client requested nonexistent cached session %s",
227 * For creating certificate attributes.
229 static const char *cert_attr_names[5][2] = {
230 { "TLS-Client-Cert-Serial", "TLS-Cert-Serial" },
231 { "TLS-Client-Cert-Expiration", "TLS-Cert-Expiraton" },
232 { "TLS-Client-Cert-Issuer", "TLS-Cert-Issuer" },
233 { "TLS-Client-Cert-Subject", "TLS-Cert-Subject" },
234 { "TLS-Client-Cert-Common-Name", "TLS-Cert-Common-Name" }
239 * Before trusting a certificate, you must make sure that the
240 * certificate is 'valid'. There are several steps that your
241 * application can take in determining if a certificate is
242 * valid. Commonly used steps are:
244 * 1.Verifying the certificate's signature, and verifying that
245 * the certificate has been issued by a trusted Certificate
248 * 2.Verifying that the certificate is valid for the present date
249 * (i.e. it is being presented within its validity dates).
251 * 3.Verifying that the certificate has not been revoked by its
252 * issuing Certificate Authority, by checking with respect to a
253 * Certificate Revocation List (CRL).
255 * 4.Verifying that the credentials presented by the certificate
256 * fulfill additional requirements specific to the application,
257 * such as with respect to access control lists or with respect
258 * to OCSP (Online Certificate Status Processing).
260 * NOTE: This callback will be called multiple times based on the
261 * depth of the root certificate chain
263 static int cbtls_verify(int ok, X509_STORE_CTX *ctx)
265 char subject[1024]; /* Used for the subject name */
266 char issuer[1024]; /* Used for the issuer name */
267 char common_name[1024];
270 EAP_HANDLER *handler = NULL;
273 int err, depth, lookup;
277 ASN1_INTEGER *sn = NULL;
278 ASN1_TIME *asn_time = NULL;
280 client_cert = X509_STORE_CTX_get_current_cert(ctx);
281 err = X509_STORE_CTX_get_error(ctx);
282 depth = X509_STORE_CTX_get_error_depth(ctx);
285 if (lookup > 1) lookup = 1;
288 * Retrieve the pointer to the SSL of the connection currently treated
289 * and the application specific data stored into the SSL object.
291 ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx());
292 handler = (EAP_HANDLER *)SSL_get_ex_data(ssl, 0);
293 request = handler->request;
294 conf = (EAP_TLS_CONF *)SSL_get_ex_data(ssl, 1);
297 * Get the Serial Number
300 sn = X509_get_serialNumber(client_cert);
301 if (sn && (sn->length < (sizeof(buf) / 2))) {
305 for (i = 0; i < sn->length; i++) {
306 sprintf(buf, "%02x", (unsigned int)sn->data[i]);
309 pairadd(&handler->certs,
310 pairmake(cert_attr_names[0][lookup], buf, T_OP_SET));
315 * Get the Expiration Date
318 asn_time = X509_get_notAfter(client_cert);
319 if (asn_time && (asn_time->length < MAX_STRING_LEN)) {
320 memcpy(buf, (char*) asn_time->data, asn_time->length);
321 buf[asn_time->length] = '\0';
322 pairadd(&handler->certs,
323 pairmake(cert_attr_names[1][lookup], buf, T_OP_SET));
327 * Get the Subject & Issuer
329 subject[0] = issuer[0] = '\0';
330 X509_NAME_oneline(X509_get_subject_name(client_cert), subject,
332 subject[sizeof(subject) - 1] = '\0';
333 if (subject[0] && (strlen(subject) < MAX_STRING_LEN)) {
334 pairadd(&handler->certs,
335 pairmake(cert_attr_names[2][lookup], subject, T_OP_SET));
338 X509_NAME_oneline(X509_get_issuer_name(ctx->current_cert), issuer,
340 issuer[sizeof(issuer) - 1] = '\0';
341 if (issuer[0] && (strlen(issuer) < MAX_STRING_LEN)) {
342 pairadd(&handler->certs,
343 pairmake(cert_attr_names[3][lookup], issuer, T_OP_SET));
347 * Get the Common Name
349 X509_NAME_get_text_by_NID(X509_get_subject_name(client_cert),
350 NID_commonName, common_name, sizeof(common_name));
351 common_name[sizeof(common_name) - 1] = '\0';
352 if (common_name[0] && (strlen(common_name) < MAX_STRING_LEN)) {
353 pairadd(&handler->certs,
354 pairmake(cert_attr_names[4][lookup], common_name, T_OP_SET));
358 const char *p = X509_verify_cert_error_string(err);
359 radlog(L_ERR,"--> verify error:num=%d:%s\n",err, p);
360 radius_pairmake(request, &request->packet->vps,
361 "Module-Failure-Message", p, T_OP_SET);
365 switch (ctx->error) {
367 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
368 radlog(L_ERR, "issuer= %s\n", issuer);
370 case X509_V_ERR_CERT_NOT_YET_VALID:
371 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
372 radlog(L_ERR, "notBefore=");
374 ASN1_TIME_print(bio_err, X509_get_notBefore(ctx->current_cert));
377 case X509_V_ERR_CERT_HAS_EXPIRED:
378 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
379 radlog(L_ERR, "notAfter=");
381 ASN1_TIME_print(bio_err, X509_get_notAfter(ctx->current_cert));
387 * If we're at the actual client cert, apply additional
392 * If the conf tells us to, check cert issuer
393 * against the specified value and fail
394 * verification if they don't match.
396 if (conf->check_cert_issuer &&
397 (strcmp(issuer, conf->check_cert_issuer) != 0)) {
398 radlog(L_AUTH, "rlm_eap_tls: Certificate issuer (%s) does not match specified value (%s)!", issuer, conf->check_cert_issuer);
403 * If the conf tells us to, check the CN in the
404 * cert against xlat'ed value, but only if the
405 * previous checks passed.
407 if (my_ok && conf->check_cert_cn) {
408 if (!radius_xlat(cn_str, sizeof(cn_str), conf->check_cert_cn, handler->request, NULL)) {
409 radlog(L_ERR, "rlm_eap_tls (%s): xlat failed.",
410 conf->check_cert_cn);
411 /* if this fails, fail the verification */
414 RDEBUG2("checking certificate CN (%s) with xlat'ed value (%s)", common_name, cn_str);
415 if (strcmp(cn_str, common_name) != 0) {
416 radlog(L_AUTH, "rlm_eap_tls: Certificate CN (%s) does not match specified value (%s)!", common_name, cn_str);
420 } /* check_cert_cn */
422 while (conf->verify_client_cert_cmd) {
426 snprintf(filename, sizeof(filename), "%s/%s.client.XXXXXXXX",
427 conf->verify_tmp_dir, progname);
428 if (mkstemp(filename) < 0) {
429 RDEBUG("Failed creating file in %s: %s",
430 conf->verify_tmp_dir, strerror(errno));
434 fp = fopen(filename, "w");
436 RDEBUG("Failed opening file %s: %s",
437 filename, strerror(errno));
441 if (!PEM_write_X509(fp, client_cert)) {
443 RDEBUG("Failed writing certificate to file");
448 if (!radius_pairmake(request, &request->packet->vps,
449 "TLS-Client-Cert-Filename",
450 filename, T_OP_SET)) {
451 RDEBUG("Failed creating TLS-Client-Cert-Filename");
456 RDEBUG("Verifying client certificate: %s",
457 conf->verify_client_cert_cmd);
458 if (radius_exec_program(conf->verify_client_cert_cmd,
460 request->packet->vps,
462 radlog(L_AUTH, "rlm_eap_tls: Certificate CN (%s) fails external verification!", common_name);
465 RDEBUG("Client certificate CN %s passed external validation", common_name);
476 if (debug_flag > 0) {
477 RDEBUG2("chain-depth=%d, ", depth);
478 RDEBUG2("error=%d", err);
480 RDEBUG2("--> User-Name = %s", handler->identity);
481 RDEBUG2("--> BUF-Name = %s", common_name);
482 RDEBUG2("--> subject = %s", subject);
483 RDEBUG2("--> issuer = %s", issuer);
484 RDEBUG2("--> verify return:%d", my_ok);
491 * Free cached session data, which is always a list of VALUE_PAIRs
493 static void eaptls_session_free(UNUSED void *parent, void *data_ptr,
494 UNUSED CRYPTO_EX_DATA *ad, UNUSED int idx,
495 UNUSED long argl, UNUSED void *argp)
497 VALUE_PAIR *vp = data_ptr;
498 if (!data_ptr) return;
505 * Create Global context SSL and use it in every new session
507 * - Load the trusted CAs
508 * - Load the Private key & the certificate
509 * - Set the Context options & Verify options
511 static SSL_CTX *init_tls_ctx(EAP_TLS_CONF *conf)
515 X509_STORE *certstore;
516 int verify_mode = SSL_VERIFY_NONE;
521 * Add all the default ciphers and message digests
522 * Create our context.
525 SSL_load_error_strings();
528 * SHA256 is in all versions of OpenSSL, but isn't
529 * initialized by default. It's needed for WiMAX
532 #ifdef HAVE_OPENSSL_EVP_SHA256
533 EVP_add_digest(EVP_sha256());
536 meth = TLSv1_method();
537 ctx = SSL_CTX_new(meth);
540 * Identify the type of certificates that needs to be loaded
542 if (conf->file_type) {
543 type = SSL_FILETYPE_PEM;
545 type = SSL_FILETYPE_ASN1;
549 * Set the password to load private key
551 if (conf->private_key_password) {
554 * We don't want to put the private key password in eap.conf, so check
555 * for our special string which indicates we should get the password
558 const char* special_string = "Apple:UseCertAdmin";
559 if (strncmp(conf->private_key_password,
561 strlen(special_string)) == 0)
564 const long max_password_len = 128;
565 snprintf(cmd, sizeof(cmd) - 1,
566 "/usr/sbin/certadmin --get-private-key-passphrase \"%s\"",
567 conf->private_key_file);
569 DEBUG2("rlm_eap: Getting private key passphrase using command \"%s\"", cmd);
571 FILE* cmd_pipe = popen(cmd, "r");
573 radlog(L_ERR, "rlm_eap: %s command failed. Unable to get private_key_password", cmd);
574 radlog(L_ERR, "rlm_eap: Error reading private_key_file %s", conf->private_key_file);
578 free(conf->private_key_password);
579 conf->private_key_password = malloc(max_password_len * sizeof(char));
580 if (!conf->private_key_password) {
581 radlog(L_ERR, "rlm_eap: Can't malloc space for private_key_password");
582 radlog(L_ERR, "rlm_eap: Error reading private_key_file %s", conf->private_key_file);
587 fgets(conf->private_key_password, max_password_len, cmd_pipe);
590 /* Get rid of newline at end of password. */
591 conf->private_key_password[strlen(conf->private_key_password) - 1] = '\0';
592 DEBUG2("rlm_eap: Password from command = \"%s\"", conf->private_key_password);
595 SSL_CTX_set_default_passwd_cb_userdata(ctx, conf->private_key_password);
596 SSL_CTX_set_default_passwd_cb(ctx, cbtls_password);
600 * Load our keys and certificates
602 * If certificates are of type PEM then we can make use
603 * of cert chain authentication using openssl api call
604 * SSL_CTX_use_certificate_chain_file. Please see how
605 * the cert chain needs to be given in PEM from
608 if (type == SSL_FILETYPE_PEM) {
609 if (!(SSL_CTX_use_certificate_chain_file(ctx, conf->certificate_file))) {
610 radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
611 radlog(L_ERR, "rlm_eap_tls: Error reading certificate file %s", conf->certificate_file);
615 } else if (!(SSL_CTX_use_certificate_file(ctx, conf->certificate_file, type))) {
616 radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
617 radlog(L_ERR, "rlm_eap_tls: Error reading certificate file %s", conf->certificate_file);
621 /* Load the CAs we trust */
622 if (conf->ca_file || conf->ca_path) {
623 if (!SSL_CTX_load_verify_locations(ctx, conf->ca_file, conf->ca_path)) {
624 radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
625 radlog(L_ERR, "rlm_eap_tls: Error reading Trusted root CA list %s",conf->ca_file );
629 if (conf->ca_file && *conf->ca_file) SSL_CTX_set_client_CA_list(ctx, SSL_load_client_CA_file(conf->ca_file));
630 if (!(SSL_CTX_use_PrivateKey_file(ctx, conf->private_key_file, type))) {
631 radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
632 radlog(L_ERR, "rlm_eap_tls: Error reading private key file %s", conf->private_key_file);
637 * Check if the loaded private key is the right one
639 if (!SSL_CTX_check_private_key(ctx)) {
640 radlog(L_ERR, "rlm_eap_tls: Private key does not match the certificate public key");
647 ctx_options |= SSL_OP_NO_SSLv2;
648 ctx_options |= SSL_OP_NO_SSLv3;
649 #ifdef SSL_OP_NO_TICKET
650 ctx_options |= SSL_OP_NO_TICKET ;
654 * SSL_OP_SINGLE_DH_USE must be used in order to prevent
655 * small subgroup attacks and forward secrecy. Always
658 * SSL_OP_SINGLE_DH_USE has an impact on the computer
659 * time needed during negotiation, but it is not very
662 ctx_options |= SSL_OP_SINGLE_DH_USE;
665 * SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS to work around issues
666 * in Windows Vista client.
667 * http://www.openssl.org/~bodo/tls-cbc.txt
668 * http://www.nabble.com/(RADIATOR)-Radiator-Version-3.16-released-t2600070.html
670 ctx_options |= SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;
672 SSL_CTX_set_options(ctx, ctx_options);
675 * TODO: Set the RSA & DH
676 * SSL_CTX_set_tmp_rsa_callback(ctx, cbtls_rsa);
677 * SSL_CTX_set_tmp_dh_callback(ctx, cbtls_dh);
681 * set the message callback to identify the type of
682 * message. For every new session, there can be a
683 * different callback argument.
685 * SSL_CTX_set_msg_callback(ctx, cbtls_msg);
688 /* Set Info callback */
689 SSL_CTX_set_info_callback(ctx, cbtls_info);
692 * Callbacks, etc. for session resumption.
694 if (conf->session_cache_enable) {
695 SSL_CTX_sess_set_new_cb(ctx, cbtls_new_session);
696 SSL_CTX_sess_set_get_cb(ctx, cbtls_get_session);
697 SSL_CTX_sess_set_remove_cb(ctx, cbtls_remove_session);
699 SSL_CTX_set_quiet_shutdown(ctx, 1);
703 * Check the certificates for revocation.
705 #ifdef X509_V_FLAG_CRL_CHECK
706 if (conf->check_crl) {
707 certstore = SSL_CTX_get_cert_store(ctx);
708 if (certstore == NULL) {
709 radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
710 radlog(L_ERR, "rlm_eap_tls: Error reading Certificate Store");
713 X509_STORE_set_flags(certstore, X509_V_FLAG_CRL_CHECK);
719 * Always verify the peer certificate
721 verify_mode |= SSL_VERIFY_PEER;
722 verify_mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
723 verify_mode |= SSL_VERIFY_CLIENT_ONCE;
724 SSL_CTX_set_verify(ctx, verify_mode, cbtls_verify);
726 if (conf->verify_depth) {
727 SSL_CTX_set_verify_depth(ctx, conf->verify_depth);
730 /* Load randomness */
731 if (!(RAND_load_file(conf->random_file, 1024*1024))) {
732 radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
733 radlog(L_ERR, "rlm_eap_tls: Error loading randomness");
738 * Set the cipher list if we were told to
740 if (conf->cipher_list) {
741 if (!SSL_CTX_set_cipher_list(ctx, conf->cipher_list)) {
742 radlog(L_ERR, "rlm_eap_tls: Error setting cipher list");
748 * Setup session caching
750 if (conf->session_cache_enable) {
752 * Create a unique context Id per EAP-TLS configuration.
754 if (conf->session_id_name) {
755 snprintf(conf->session_context_id,
756 sizeof(conf->session_context_id),
757 "FreeRADIUS EAP-TLS %s",
758 conf->session_id_name);
760 snprintf(conf->session_context_id,
761 sizeof(conf->session_context_id),
762 "FreeRADIUS EAP-TLS %p", conf);
766 * Cache it, and DON'T auto-clear it.
768 SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_SERVER | SSL_SESS_CACHE_NO_AUTO_CLEAR);
770 SSL_CTX_set_session_id_context(ctx,
771 (unsigned char *) conf->session_context_id,
772 (unsigned int) strlen(conf->session_context_id));
775 * Our timeout is in hours, this is in seconds.
777 SSL_CTX_set_timeout(ctx, conf->session_timeout * 3600);
780 * Set the maximum number of entries in the
783 SSL_CTX_sess_set_cache_size(ctx, conf->session_cache_size);
786 SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
790 * Register the application indices. We can't use
791 * hard-coded "0" and "1" as before, because we need to
792 * set up a "free" handler for the cached session
795 if (eaptls_handle_idx < 0) {
796 eaptls_handle_idx = SSL_get_ex_new_index(0, "eaptls_handle_idx",
800 if (eaptls_conf_idx < 0) {
801 eaptls_conf_idx = SSL_get_ex_new_index(0, "eaptls_conf_idx",
805 if (eaptls_session_idx < 0) {
806 eaptls_session_idx = SSL_get_ex_new_index(0, "eaptls_session_idx",
808 eaptls_session_free);
816 * Detach the EAP-TLS module.
818 static int eaptls_detach(void *arg)
823 inst = (eap_tls_t *) arg;
827 memset(conf, 0, sizeof(*conf));
832 if (inst->ctx) SSL_CTX_free(inst->ctx);
842 * Attach the EAP-TLS module.
844 static int eaptls_attach(CONF_SECTION *cs, void **instance)
849 /* Store all these values in the data structure for later references */
850 inst = (eap_tls_t *)malloc(sizeof(*inst));
852 radlog(L_ERR, "rlm_eap_tls: out of memory");
855 memset(inst, 0, sizeof(*inst));
858 * Parse the config file & get all the configured values
860 conf = (EAP_TLS_CONF *)malloc(sizeof(*conf));
863 radlog(L_ERR, "rlm_eap_tls: out of memory");
866 memset(conf, 0, sizeof(*conf));
869 if (cf_section_parse(cs, conf, module_config) < 0) {
875 * The EAP RFC's say 1020, but we're less picky.
877 if (conf->fragment_size < 100) {
878 radlog(L_ERR, "rlm_eap_tls: Fragment size is too small.");
884 * The maximum size for a RADIUS packet is 4096,
885 * minus the header (20), Message-Authenticator (18),
886 * and State (18), etc. results in about 4000 bytes of data
887 * that can be devoted *solely* to EAP.
889 if (conf->fragment_size > 4000) {
890 radlog(L_ERR, "rlm_eap_tls: Fragment size is too large.");
896 * Account for the EAP header (4), and the EAP-TLS header
897 * (6), as per Section 4.2 of RFC 2716. What's left is
898 * the maximum amount of data we read from a TLS buffer.
900 conf->fragment_size -= 10;
903 * This magic makes the administrators life HUGELY easier
904 * on initial deployments.
906 * If the server starts up in debugging mode, AND the
907 * bootstrap command is configured, AND it exists, AND
908 * there is no server certificate
910 if (conf->make_cert_command && (debug_flag >= 2)) {
913 if ((stat(conf->make_cert_command, &buf) == 0) &&
914 (stat(conf->certificate_file, &buf) < 0) &&
916 (radius_exec_program(conf->make_cert_command, NULL, 1,
917 NULL, 0, NULL, NULL, 0) != 0)) {
927 inst->ctx = init_tls_ctx(conf);
928 if (inst->ctx == NULL) {
933 if (load_dh_params(inst->ctx, conf->dh_file) < 0) {
938 if (generate_eph_rsa_key(inst->ctx) < 0) {
943 if (conf->verify_tmp_dir) {
946 if (chmod(conf->verify_tmp_dir, S_IRWXU) < 0) {
947 radlog(L_ERR, "rlm_eap_tls: Failed changing permissions on %s: %s", conf->verify_tmp_dir, strerror(errno));
953 if (conf->verify_client_cert_cmd && !conf->verify_tmp_dir) {
954 radlog(L_ERR, "rlm_eap_tls: You MUST set the verify directory in order to use verify_client_cmd");
966 * Send an initial eap-tls request to the peer.
968 * Frame eap reply packet.
969 * len = header + type + tls_typedata
970 * tls_typedata = flags(Start (S) bit set, and no data)
972 * Once having received the peer's Identity, the EAP server MUST
973 * respond with an EAP-TLS/Start packet, which is an
974 * EAP-Request packet with EAP-Type=EAP-TLS, the Start (S) bit
975 * set, and no data. The EAP-TLS conversation will then begin,
976 * with the peer sending an EAP-Response packet with
977 * EAP-Type = EAP-TLS. The data field of that packet will
980 * Fragment length is Framed-MTU - 4.
982 * http://mail.frascone.com/pipermail/public/eap/2003-July/001426.html
984 static int eaptls_initiate(void *type_arg, EAP_HANDLER *handler)
990 int client_cert = TRUE;
992 REQUEST *request = handler->request;
994 inst = (eap_tls_t *)type_arg;
997 handler->finished = FALSE;
1000 * Manually flush the sessions every so often. If HALF
1001 * of the session lifetime has passed since we last
1002 * flushed, then flush it again.
1004 * FIXME: Also do it every N sessions?
1006 if (inst->conf->session_cache_enable &&
1007 ((inst->conf->session_last_flushed + (inst->conf->session_timeout * 1800)) <= request->timestamp)) {
1008 RDEBUG2("Flushing SSL sessions (of #%ld)",
1009 SSL_CTX_sess_number(inst->ctx));
1011 SSL_CTX_flush_sessions(inst->ctx, request->timestamp);
1012 inst->conf->session_last_flushed = request->timestamp;
1016 * If we're TTLS or PEAP, then do NOT require a client
1019 * FIXME: This should be more configurable.
1021 if (handler->eap_type != PW_EAP_TLS) {
1022 vp = pairfind(handler->request->config_items,
1023 PW_EAP_TLS_REQUIRE_CLIENT_CERT, 0);
1025 client_cert = FALSE;
1027 client_cert = vp->vp_integer;
1032 * Every new session is started only from EAP-TLS-START.
1033 * Before Sending EAP-TLS-START, open a new SSL session.
1034 * Create all the required data structures & store them
1035 * in Opaque. So that we can use these data structures
1036 * when we get the response
1038 ssn = eaptls_new_session(inst->ctx, client_cert);
1044 * Verify the peer certificate, if asked.
1047 RDEBUG2("Requiring client certificate");
1048 verify_mode = SSL_VERIFY_PEER;
1049 verify_mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
1050 verify_mode |= SSL_VERIFY_CLIENT_ONCE;
1052 SSL_set_verify(ssn->ssl, verify_mode, cbtls_verify);
1055 * Create a structure for all the items required to be
1056 * verified for each client and set that as opaque data
1059 * NOTE: If we want to set each item sepearately then
1060 * this index should be global.
1062 SSL_set_ex_data(ssn->ssl, 0, (void *)handler);
1063 SSL_set_ex_data(ssn->ssl, 1, (void *)inst->conf);
1065 ssn->length_flag = inst->conf->include_length;
1068 * We use default fragment size, unless the Framed-MTU
1069 * tells us it's too big. Note that we do NOT account
1070 * for the EAP-TLS headers if conf->fragment_size is
1071 * large, because that config item looks to be confusing.
1073 * i.e. it should REALLY be called MTU, and the code here
1074 * should figure out what that means for TLS fragment size.
1075 * asking the administrator to know the internal details
1076 * of EAP-TLS in order to calculate fragment sizes is
1079 ssn->offset = inst->conf->fragment_size;
1080 vp = pairfind(handler->request->packet->vps, PW_FRAMED_MTU, 0);
1081 if (vp && ((vp->vp_integer - 14) < ssn->offset)) {
1083 * Discount the Framed-MTU by:
1085 * 4 : EAP header (code + id + length)
1086 * 1 : EAP type == EAP-TLS
1088 * 4 : EAP-TLS Message length
1089 * (even if conf->include_length == 0,
1094 ssn->offset = vp->vp_integer - 14;
1097 handler->opaque = ((void *)ssn);
1098 handler->free_opaque = session_free;
1100 RDEBUG2("Initiate");
1103 * Set up type-specific information.
1105 switch (handler->eap_type) {
1108 ssn->prf_label = "client EAP encryption";
1112 ssn->prf_label = "ttls keying material";
1116 * PEAP-specific breakage.
1120 * As it is a poorly designed protocol, PEAP uses
1121 * bits in the TLS header to indicate PEAP
1122 * version numbers. For now, we only support
1123 * PEAP version 0, so it doesn't matter too much.
1124 * However, if we support later versions of PEAP,
1125 * we will need this flag to indicate which
1126 * version we're currently dealing with.
1128 ssn->peap_flag = 0x00;
1131 * PEAP version 0 requires 'include_length = no',
1132 * so rather than hoping the user figures it out,
1135 ssn->length_flag = 0;
1137 ssn->prf_label = "client EAP encryption";
1141 if (inst->conf->session_cache_enable) {
1142 ssn->allow_session_resumption = 1; /* otherwise it's zero */
1146 * TLS session initialization is over. Now handle TLS
1147 * related handshaking or application data.
1149 status = eaptls_start(handler->eap_ds, ssn->peap_flag);
1150 RDEBUG2("Start returned %d", status);
1155 * The next stage to process the packet.
1157 handler->stage = AUTHENTICATE;
1163 * Do authentication, by letting EAP-TLS do most of the work.
1165 static int eaptls_authenticate(void *arg, EAP_HANDLER *handler)
1167 eaptls_status_t status;
1168 tls_session_t *tls_session = (tls_session_t *) handler->opaque;
1169 REQUEST *request = handler->request;
1170 eap_tls_t *inst = (eap_tls_t *) arg;
1172 RDEBUG2("Authenticate");
1174 status = eaptls_process(handler);
1175 RDEBUG2("eaptls_process returned %d\n", status);
1178 * EAP-TLS handshake was successful, return an
1179 * EAP-TLS-Success packet here.
1181 case EAPTLS_SUCCESS:
1185 * The TLS code is still working on the TLS
1186 * exchange, and it's a valid TLS request.
1189 case EAPTLS_HANDLED:
1193 * Handshake is done, proceed with decoding tunneled
1197 RDEBUG2("Received unexpected tunneled data after successful handshake.");
1199 if ((debug_flag > 2) && fr_log_fp) {
1201 unsigned int data_len;
1202 unsigned char buffer[1024];
1204 data_len = (tls_session->record_minus)(&tls_session->dirty_in,
1205 buffer, sizeof(buffer));
1206 log_debug(" Tunneled data (%u bytes)\n", data_len);
1207 for (i = 0; i < data_len; i++) {
1208 if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, " %x: ", i);
1209 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1211 fprintf(fr_log_fp, "%02x ", buffer[i]);
1213 fprintf(fr_log_fp, "\n");
1217 eaptls_fail(handler, 0);
1222 * Anything else: fail.
1224 * Also, remove the session from the cache so that
1225 * the client can't re-use it.
1228 if (inst->conf->session_cache_enable) {
1229 SSL_CTX_remove_session(inst->ctx,
1230 tls_session->ssl->session);
1237 * New sessions cause some additional information to be
1240 if (!SSL_session_reused(tls_session->ssl)) {
1242 * FIXME: Store miscellaneous data.
1244 RDEBUG2("Adding user data to cached session");
1247 SSL_SESSION_set_ex_data(tls_session->ssl->session,
1248 ssl_session_idx_user_session, session_data);
1252 * FIXME: Retrieve miscellaneous data.
1255 data = SSL_SESSION_get_ex_data(tls_session->ssl->session,
1256 ssl_session_idx_user_session);
1258 if (!session_data) {
1259 radlog_request(L_ERR, 0, request,
1260 "No user session data in cached session - "
1266 RDEBUG2("Retrieved session data from cached session");
1270 * Success: Automatically return MPPE keys.
1272 return eaptls_success(handler, 0);
1276 * The module name should be the only globally exported symbol.
1277 * That is, everything else should be 'static'.
1279 EAP_TYPE rlm_eap_tls = {
1281 eaptls_attach, /* attach */
1282 eaptls_initiate, /* Start the initial request */
1283 NULL, /* authorization */
1284 eaptls_authenticate, /* authentication */
1285 eaptls_detach /* detach */