sae: implementation

SAE (Simultaneous Authentication of Equals) takes place during
authentication, and followed by EAPoL/4-way handshake. This
module handles the entire SAE commit/confirm exchange. This was
done similar to eapol.

SAE begins when sae_register is called. At this point a commit
message will be created and sent out which kicks off the SAE
authentication procedure.

The commit/confirm exchange is very similar to EAP-PWD, so all
the ecc utility functions could be re-used as-is. A few new ecc
utility functions were added to conform to the 80211 'blinding'
technique for computing the password element.

Makefile.am

@@ -111,6 +111,7 @@ src_iwd_SOURCES = src/main.c linux/nl80211.h \
 					src/eap-pwd.c \
 					src/ecc.h src/ecc.c \
 					src/adhoc.h src/adhoc.c \
+					src/sae.h src/sae.c \
 					$(builtin_sources)
 
 src_iwd_LDADD = ell/libell-internal.la -ldl

src/sae.h

@@ -0,0 +1,39 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2018  Intel Corporation. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+struct sae_sm;
+struct handshake_state;
+
+typedef int (*sae_tx_packet_func_t)(const uint8_t *dest, const uint8_t *frame,
+					size_t len, void *user_data);
+
+typedef void (*sae_complete_func_t)(uint16_t status, void *user_data);
+
+struct sae_sm *sae_sm_new(struct handshake_state *hs, sae_tx_packet_func_t tx,
+				sae_complete_func_t complete, void *user_data);
+void sae_sm_free(struct sae_sm *sm);
+
+void sae_rx_packet(struct sae_sm *sm, const uint8_t *src,
+				const uint8_t *frame, size_t len);
+void sae_timeout(struct sae_sm *sm);
+
+void sae_start(struct sae_sm *sm);