From: Martin Willi <martin@revosec.ch>
Date: Wed, 25 Mar 2015 13:31:24 +0000 (+0100)
Subject: aesni: Add a common key schedule class for AES
X-Git-Tag: 5.3.1dr1~17^2~24
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=431f452ed4551099da26f904929da7c077f2590f;p=thirdparty%2Fstrongswan.git

aesni: Add a common key schedule class for AES
---

diff --git a/src/libstrongswan/plugins/aesni/Makefile.am b/src/libstrongswan/plugins/aesni/Makefile.am
index 92310a7c14..817afa40ae 100644
--- a/src/libstrongswan/plugins/aesni/Makefile.am
+++ b/src/libstrongswan/plugins/aesni/Makefile.am
@@ -2,6 +2,7 @@ AM_CPPFLAGS = \
 	-I$(top_srcdir)/src/libstrongswan
 
 AM_CFLAGS = \
+	-maes \
 	$(PLUGIN_CFLAGS)
 
 if MONOLITHIC
@@ -11,6 +12,7 @@ plugin_LTLIBRARIES = libstrongswan-aesni.la
 endif
 
 libstrongswan_aesni_la_SOURCES = \
+	aesni_key.h aesni_key.c \
 	aesni_plugin.h aesni_plugin.c
 
 libstrongswan_aesni_la_LDFLAGS = -module -avoid-version
diff --git a/src/libstrongswan/plugins/aesni/aesni_key.c b/src/libstrongswan/plugins/aesni/aesni_key.c
new file mode 100644
index 0000000000..6345dd2601
--- /dev/null
+++ b/src/libstrongswan/plugins/aesni/aesni_key.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2015 Martin Willi
+ * Copyright (C) 2015 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include "aesni_key.h"
+
+/**
+ * Rounds used for each AES key size
+ */
+#define AES128_ROUNDS 10
+
+typedef struct private_aesni_key_t private_aesni_key_t;
+
+/**
+ * Private data of an aesni_key_t object.
+ */
+struct private_aesni_key_t {
+
+	/**
+	 * Public aesni_key_t interface.
+	 */
+	aesni_key_t public;
+};
+
+/**
+ * Invert round encryption keys to get a decryption key schedule
+ */
+static void reverse_key(aesni_key_t *this)
+{
+	__m128i t[this->rounds + 1];
+	int i;
+
+	for (i = 0; i <= this->rounds; i++)
+	{
+		t[i] = this->schedule[i];
+	}
+	this->schedule[this->rounds] = t[0];
+	for (i = 1; i < this->rounds; i++)
+	{
+		this->schedule[this->rounds - i] = _mm_aesimc_si128(t[i]);
+	}
+	this->schedule[0] = t[this->rounds];
+
+	memwipe(t, sizeof(t));
+}
+
+METHOD(aesni_key_t, destroy, void,
+	private_aesni_key_t *this)
+{
+	memwipe(this, sizeof(*this) + (this->public.rounds + 1) * AES_BLOCK_SIZE);
+	free(this);
+}
+
+/**
+ * See header
+ */
+aesni_key_t *aesni_key_create(bool encrypt, chunk_t key)
+{
+	private_aesni_key_t *this;
+	int rounds;
+
+	switch (key.len)
+	{
+		default:
+			return NULL;
+	}
+
+	INIT_EXTRA(this, (rounds + 1) * AES_BLOCK_SIZE,
+		.public = {
+			.destroy = _destroy,
+			.rounds = rounds,
+		},
+	);
+
+	switch (key.len)
+	{
+		default:
+			break;
+	}
+
+	if (!encrypt)
+	{
+		reverse_key(&this->public);
+	}
+
+	return &this->public;
+}
diff --git a/src/libstrongswan/plugins/aesni/aesni_key.h b/src/libstrongswan/plugins/aesni/aesni_key.h
new file mode 100644
index 0000000000..12dcd221d5
--- /dev/null
+++ b/src/libstrongswan/plugins/aesni/aesni_key.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2015 Martin Willi
+ * Copyright (C) 2015 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+/**
+ * @defgroup aesni_key aesni_key
+ * @{ @ingroup aesni
+ */
+
+#ifndef AESNI_KEY_H_
+#define AESNI_KEY_H_
+
+#include <library.h>
+
+#include <wmmintrin.h>
+
+/**
+ * AES block size, in bytes
+ */
+#define AES_BLOCK_SIZE 16
+
+typedef struct aesni_key_t aesni_key_t;
+
+/**
+ * Key schedule for encryption/decryption using on AES-NI.
+ */
+struct aesni_key_t {
+
+	/**
+	 * Destroy a aesni_key_t.
+	 */
+	void (*destroy)(aesni_key_t *this);
+
+	/**
+	 * Number of AES rounds (10, 12, 14)
+	 */
+	int rounds;
+
+	/**
+	 * Key schedule, for each round + the round 0 (whitening)
+	 */
+	__attribute__((aligned(sizeof(__m128i)))) __m128i schedule[];
+};
+
+/**
+ * Create a AESNI key schedule instance.
+ *
+ * @param encrypt		TRUE for encryption schedule, FALSE for decryption
+ * @param key			non-expanded crypto key, 16, 24 or 32 bytes
+ * @return				key schedule, NULL on invalid key size
+ */
+aesni_key_t *aesni_key_create(bool encrypt, chunk_t key);
+
+#endif /** AESNI_KEY_H_ @}*/