core: Add support for AES-CMAC hashing function

Makefile.am

@@ -43,6 +43,7 @@ src_iwd_SOURCES = src/main.c linux/nl80211.h linux/kdbus.h \
 					src/kdbus.h src/kdbus.c \
 					src/netdev.h src/netdev.c \
 					src/wiphy.h src/wiphy.c \
+					src/aes.h src/aes.c \
 					src/md5.h src/md5.c \
 					src/sha1.h src/sha1.c \
 					src/sha256.h src/sha256.c \

src/aes.c

@@ -0,0 +1,130 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2013-2014  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
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/socket.h>
+
+#ifndef PF_ALG
+#include <linux/types.h>
+
+struct sockaddr_alg {
+	__u16   salg_family;
+	__u8    salg_type[14];
+	__u32   salg_feat;
+	__u32   salg_mask;
+	__u8    salg_name[64];
+};
+
+#define ALG_SET_KEY                     1
+
+#define PF_ALG		38	/* Algorithm sockets.  */
+#define AF_ALG		PF_ALG
+#else
+#include <linux/if_alg.h>
+#endif
+
+#ifndef SOL_ALG
+#define SOL_ALG		279
+#endif
+
+#include "src/aes.h"
+
+/* Maximum message length that can be passed to aes_cmac */
+#define CMAC_MSG_MAX	80
+
+static int cmac_aes_setup(void)
+{
+	struct sockaddr_alg salg;
+	int fd;
+
+	fd = socket(PF_ALG, SOCK_SEQPACKET | SOCK_CLOEXEC, 0);
+	if (fd < 0)
+		return -1;
+
+	memset(&salg, 0, sizeof(salg));
+	salg.salg_family = AF_ALG;
+	strcpy((char *) salg.salg_type, "hash");
+	strcpy((char *) salg.salg_name, "cmac(aes)");
+
+	if (bind(fd, (struct sockaddr *) &salg, sizeof(salg)) < 0) {
+		close(fd);
+		return -1;
+	}
+
+	return fd;
+}
+
+static int alg_new(int fd, const void *keyval, socklen_t keylen)
+{
+	if (setsockopt(fd, SOL_ALG, ALG_SET_KEY, keyval, keylen) < 0)
+		return -1;
+
+	return accept4(fd, NULL, 0, SOCK_CLOEXEC);
+}
+
+bool cmac_aes(const void *key, size_t key_len,
+		const void *msg, size_t msg_len, void *tag, size_t size)
+{
+	ssize_t len;
+	int fd, alg_fd;
+	bool result;
+
+	if (msg_len > CMAC_MSG_MAX)
+		return false;
+
+	alg_fd = cmac_aes_setup();
+	if (alg_fd < 0)
+		return false;
+
+	fd = alg_new(alg_fd, key, key_len);
+	if (fd < 0) {
+		close(alg_fd);
+		return false;
+	}
+
+	len = send(fd, msg, msg_len, 0);
+	if (len < 0) {
+		result = false;
+		goto done;
+	}
+
+	len = read(fd, tag, size);
+	if (len < 0) {
+		result = false;
+		goto done;
+	}
+
+	result = true;
+
+done:
+	close(fd);
+	close(alg_fd);
+
+	return result;
+}

src/aes.h

@@ -0,0 +1,26 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2013-2014  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
+ *
+ */
+
+#include <stdbool.h>
+
+bool cmac_aes(const void *key, size_t key_len,
+		const void *msg, size_t msg_len, void *tag, size_t size);