1 files changed, 392 insertions, 0 deletions
diff --git a/src/modules/rlm_eap/types/rlm_eap_ttls/rlm_eap_ttls.c b/src/modules/rlm_eap/types/rlm_eap_ttls/rlm_eap_ttls.c
new file mode 100644
index 0000000..4e53c92
--- /dev/null
+++ b/src/modules/rlm_eap/types/rlm_eap_ttls/rlm_eap_ttls.c
@@ -0,0 +1,392 @@
+/*
+ * 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("$Id$")
+USES_APPLE_DEPRECATED_API	/* OpenSSL API has been deprecated by Apple */
+
+#include "eap_ttls.h"
+
+typedef struct rlm_eap_ttls_t {
+	/*
+	 *	TLS configuration
+	 */
+	char const *tls_conf_name;
+	fr_tls_server_conf_t *tls_conf;
+
+	/*
+	 *	Default tunneled EAP type
+	 */
+	char const *default_method_name;
+	int default_method;
+
+	/*
+	 *	Use the reply attributes from the tunneled session in
+	 *	the non-tunneled reply to the client.
+	 */
+	bool use_tunneled_reply;
+
+	/*
+	 *	Use SOME of the request attributes from outside of the
+	 *	tunneled session in the tunneled request
+	 */
+	bool copy_request_to_tunnel;
+
+	/*
+	 *	RFC 5281 (TTLS) says that the length field MUST NOT be
+	 *	in fragments after the first one.  However, we've done
+	 *	it that way for years, and no one has complained.
+	 *
+	 *	In the interests of allowing the server to follow the
+	 *	RFC, we add the option here.  If set to "no", it sends
+	 *	the length field in ONLY the first fragment.
+	 */
+	bool include_length;
+
+	/*
+	 *	Virtual server for inner tunnel session.
+	 */
+	char const *virtual_server;
+
+	/*
+	 * 	Do we do require a client cert?
+	 */
+	bool req_client_cert;
+} rlm_eap_ttls_t;
+
+
+static CONF_PARSER module_config[] = {
+	{ "tls", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_eap_ttls_t, tls_conf_name), NULL },
+	{ "default_eap_type", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_eap_ttls_t, default_method_name), "md5" },
+	{ "copy_request_to_tunnel", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_eap_ttls_t, copy_request_to_tunnel), "no" },
+	{ "use_tunneled_reply", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_eap_ttls_t, use_tunneled_reply), "no" },
+	{ "virtual_server", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_eap_ttls_t, virtual_server), NULL },
+	{ "include_length", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_eap_ttls_t, include_length), "yes" },
+	{ "require_client_cert", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_eap_ttls_t, req_client_cert), "no" },
+	CONF_PARSER_TERMINATOR
+};
+
+
+/*
+ *	Attach the module.
+ */
+static int mod_instantiate(CONF_SECTION *cs, void **instance)
+{
+	rlm_eap_ttls_t		*inst;
+
+	*instance = inst = talloc_zero(cs, rlm_eap_ttls_t);
+	if (!inst) return -1;
+
+	/*
+	 *	Parse the configuration attributes.
+	 */
+	if (cf_section_parse(cs, inst, module_config) < 0) {
+		return -1;
+	}
+
+	if (!inst->virtual_server) {
+		ERROR("rlm_eap_ttls: A 'virtual_server' MUST be defined for security");
+		return -1;
+	}
+
+	/*
+	 *	Convert the name to an integer, to make it easier to
+	 *	handle.
+	 */
+	inst->default_method = eap_name2type(inst->default_method_name);
+	if (inst->default_method < 0) {
+		ERROR("rlm_eap_ttls: Unknown EAP type %s",
+		       inst->default_method_name);
+		return -1;
+	}
+
+	/*
+	 *	Read tls configuration, either from group given by 'tls'
+	 *	option, or from the eap-tls configuration.
+	 */
+	inst->tls_conf = eaptls_conf_parse(cs, "tls");
+
+	if (!inst->tls_conf) {
+		ERROR("rlm_eap_ttls: Failed initializing SSL context");
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ *	Allocate the TTLS per-session data
+ */
+static ttls_tunnel_t *ttls_alloc(TALLOC_CTX *ctx, rlm_eap_ttls_t *inst)
+{
+	ttls_tunnel_t *t;
+
+	t = talloc_zero(ctx, ttls_tunnel_t);
+
+	t->default_method = inst->default_method;
+	t->copy_request_to_tunnel = inst->copy_request_to_tunnel;
+	t->use_tunneled_reply = inst->use_tunneled_reply;
+	t->virtual_server = inst->virtual_server;
+	return t;
+}
+
+
+/*
+ *	Send an initial eap-tls request to the peer, using the libeap functions.
+ */
+static int mod_session_init(void *type_arg, eap_handler_t *handler)
+{
+	int		status;
+	tls_session_t	*ssn;
+	rlm_eap_ttls_t	*inst;
+	VALUE_PAIR	*vp;
+	bool		client_cert;
+	REQUEST		*request = handler->request;
+
+	inst = type_arg;
+
+	handler->tls = true;
+
+	/*
+	 *	Check if we need a client certificate.
+	 */
+
+	/*
+	 * EAP-TLS-Require-Client-Cert attribute will override
+	 * the require_client_cert configuration option.
+	 */
+	vp = fr_pair_find_by_num(handler->request->config, PW_EAP_TLS_REQUIRE_CLIENT_CERT, 0, TAG_ANY);
+	if (vp) {
+		client_cert = vp->vp_integer ? true : false;
+	} else {
+		client_cert = inst->req_client_cert;
+	}
+
+	/*
+	 *	Allow TLS 1.3, it works.
+	 */
+	ssn = eaptls_session(handler, inst->tls_conf, client_cert, true);
+	if (!ssn) {
+		return 0;
+	}
+
+	handler->opaque = ((void *)ssn);
+
+	/*
+	 *	Set the label to a fixed string.  For TLS 1.3, the
+	 *	label is the same for all TLS-based EAP methods.  If
+	 *	the client is using TLS 1.3, then eaptls_success()
+	 *	will over-ride this label with the correct label for
+	 *	TLS 1.3.
+	 */
+	ssn->label = "ttls keying material";
+
+	/*
+	 *	TLS session initialization is over.  Now handle TLS
+	 *	related handshaking or application data.
+	 */
+	status = eaptls_start(handler->eap_ds, ssn->peap_flag);
+	if ((status == FR_TLS_INVALID) || (status == FR_TLS_FAIL)) {
+		REDEBUG("[eaptls start] = %s", fr_int2str(fr_tls_status_table, status, "<INVALID>"));
+	} else {
+		RDEBUG3("[eaptls start] = %s", fr_int2str(fr_tls_status_table, status, "<INVALID>"));
+	}
+	if (status == 0) return 0;
+
+	/*
+	 *	The next stage to process the packet.
+	 */
+	handler->stage = PROCESS;
+
+	return 1;
+}
+
+
+/*
+ *	Do authentication, by letting EAP-TLS do most of the work.
+ */
+static int mod_process(void *arg, eap_handler_t *handler)
+{
+	int rcode;
+	int ret = 0;
+	fr_tls_status_t	status;
+	rlm_eap_ttls_t *inst = (rlm_eap_ttls_t *) arg;
+	tls_session_t *tls_session = (tls_session_t *) handler->opaque;
+	ttls_tunnel_t *t = (ttls_tunnel_t *) tls_session->opaque;
+	REQUEST *request = handler->request;
+
+	RDEBUG2("Authenticate");
+
+	tls_session->length_flag = inst->include_length;
+
+	/*
+	 *	Process TLS layer until done.
+	 */
+	status = eaptls_process(handler);
+	if ((status == FR_TLS_INVALID) || (status == FR_TLS_FAIL)) {
+		REDEBUG("[eaptls process] = %s", fr_int2str(fr_tls_status_table, status, "<INVALID>"));
+	} else {
+		RDEBUG3("[eaptls process] = %s", fr_int2str(fr_tls_status_table, status, "<INVALID>"));
+	}
+
+	/*
+	 *	Make request available to any SSL callbacks
+	 */
+	SSL_set_ex_data(tls_session->ssl, FR_TLS_EX_INDEX_REQUEST, request);
+	switch (status) {
+	/*
+	 *	EAP-TLS handshake was successful, tell the
+	 *	client to keep talking.
+	 *
+	 *	If this was EAP-TLS, we would just return
+	 *	an EAP-TLS-Success packet here.
+	 */
+	case FR_TLS_SUCCESS:
+		if (SSL_session_reused(tls_session->ssl)) {
+			RDEBUG("Skipping Phase2 due to session resumption");
+			goto do_keys;
+		}
+
+		if (t && t->authenticated) {
+			if (t->accept_vps) {
+				RDEBUG2("Using saved attributes from the original Access-Accept");
+				rdebug_pair_list(L_DBG_LVL_2, request, t->accept_vps, NULL);
+				fr_pair_list_mcopy_by_num(handler->request->reply,
+					   &handler->request->reply->vps,
+					   &t->accept_vps, 0, 0, TAG_ANY);
+			} else if (t->use_tunneled_reply) {
+				RDEBUG2("No saved attributes in the original Access-Accept");
+			}
+
+		do_keys:
+			/*
+			 *	Success: Automatically return MPPE keys.
+			 */
+			ret = eaptls_success(handler, 0);
+			goto done;
+		} else {
+			eaptls_request(handler->eap_ds, tls_session);
+		}
+		ret = 1;
+		goto done;
+
+	/*
+	 *	The TLS code is still working on the TLS
+	 *	exchange, and it's a valid TLS request.
+	 *	do nothing.
+	 */
+	case FR_TLS_HANDLED:
+		ret = 1;
+		goto done;
+
+	/*
+	 *	Handshake is done, proceed with decoding tunneled
+	 *	data.
+	 */
+	case FR_TLS_OK:
+		break;
+
+	/*
+	 *	Anything else: fail.
+	 */
+	default:
+		ret = 0;
+		goto done;
+	}
+
+	/*
+	 *	Session is established, proceed with decoding
+	 *	tunneled data.
+	 */
+	RDEBUG2("Session established.  Proceeding to decode tunneled attributes");
+
+	/*
+	 *	We may need TTLS data associated with the session, so
+	 *	allocate it here, if it wasn't already alloacted.
+	 */
+	if (!tls_session->opaque) {
+		tls_session->opaque = ttls_alloc(tls_session, inst);
+	}
+
+	/*
+	 *	Process the TTLS portion of the request.
+	 */
+	rcode = eapttls_process(handler, tls_session);
+	switch (rcode) {
+	case PW_CODE_ACCESS_REJECT:
+		eaptls_fail(handler, 0);
+		ret = 0;
+		goto done;
+
+		/*
+		 *	Access-Challenge, continue tunneled conversation.
+		 */
+	case PW_CODE_ACCESS_CHALLENGE:
+		eaptls_request(handler->eap_ds, tls_session);
+		ret = 1;
+		goto done;
+
+		/*
+		 *	Success: Automatically return MPPE keys.
+		 */
+	case PW_CODE_ACCESS_ACCEPT:
+		goto do_keys;
+
+		/*
+		 *	No response packet, MUST be proxying it.
+		 *	The main EAP module will take care of discovering
+		 *	that the request now has a "proxy" packet, and
+		 *	will proxy it, rather than returning an EAP packet.
+		 */
+	case PW_CODE_STATUS_CLIENT:
+#ifdef WITH_PROXY
+		rad_assert(handler->request->proxy != NULL);
+#endif
+		ret = 1;
+		goto done;
+
+	default:
+		break;
+	}
+
+	/*
+	 *	Something we don't understand: Reject it.
+	 */
+	eaptls_fail(handler, 0);
+
+done:
+	SSL_set_ex_data(tls_session->ssl, FR_TLS_EX_INDEX_REQUEST, NULL);
+
+	return ret;
+}
+
+/*
+ *	The module name should be the only globally exported symbol.
+ *	That is, everything else should be 'static'.
+ */
+extern rlm_eap_module_t rlm_eap_ttls;
+rlm_eap_module_t rlm_eap_ttls = {
+	.name		= "eap_ttls",
+	.instantiate	= mod_instantiate,	/* Create new submodule instance */
+	.session_init	= mod_session_init,	/* Initialise a new EAP session */
+	.process	= mod_process		/* Process next round of EAP method */
+};