From 1693246bbcc6381e53a1cbfae1aa5322363d731e Mon Sep 17 00:00:00 2001
From: rasky <rasky@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Wed, 29 Sep 2010 13:38:54 +0000
Subject: [PATCH] SEC: Add symmetric ciphers generic interface.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4346 38d2e660-2303-0410-9eaa-f027e97ec537
---
 bertos/sec/cipher.c |  82 ++++++++++++++++++++++
 bertos/sec/cipher.h | 161 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 243 insertions(+)
 create mode 100644 bertos/sec/cipher.c
 create mode 100644 bertos/sec/cipher.h

diff --git a/bertos/sec/cipher.c b/bertos/sec/cipher.c
new file mode 100644
index 00000000..22bebe60
--- /dev/null
+++ b/bertos/sec/cipher.c
@@ -0,0 +1,82 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos 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
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \brief Generic interface for symmetric block ciphers.
+ * \author Giovanni Bajo <rasky@develer.com>
+ *
+ */
+
+#include "cipher.h"
+#include <sec/util.h>
+
+void cipher_cbc_encrypt(BlockCipher *c, void *block)
+{
+	xor_block(c->buf, c->buf, block, c->block_len);
+	c->enc_block(c, c->buf);
+	memcpy(block, c->buf, c->block_len);
+}
+
+void cipher_cbc_decrypt(BlockCipher *c, void *block)
+{
+	uint8_t temp[c->block_len];
+	memcpy(temp, block, c->block_len);
+
+	c->dec_block(c, block);
+	xor_block(block, block, c->buf, c->block_len);
+
+	memcpy(c->buf, temp, c->block_len);
+}
+
+static void ctr_increment(void *buf, size_t len)
+{
+	uint8_t *data = (uint8_t*)buf;
+	while (len--)
+		if (LIKELY(++data[len] != 0))
+			return;
+}
+
+void cipher_ctr_encrypt(BlockCipher *c, void *block)
+{
+	uint8_t temp[c->block_len];
+
+	memcpy(temp, c->buf, c->block_len);
+	c->enc_block(c, temp);
+	xor_block(block, block, temp, c->block_len);
+
+	PURGE(temp);
+	ctr_increment(c->buf, c->block_len);
+}
+
+void cipher_ctr_decrypt(BlockCipher *c, void *block)
+{
+	cipher_ctr_encrypt(c, block);
+}
diff --git a/bertos/sec/cipher.h b/bertos/sec/cipher.h
new file mode 100644
index 00000000..f7aee505
--- /dev/null
+++ b/bertos/sec/cipher.h
@@ -0,0 +1,161 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos 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
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \brief Generic interface for symmetric block ciphers.
+ * \author Giovanni Bajo <rasky@develer.com>
+ *
+ */
+
+#ifndef SEC_CIPHER_H
+#define SEC_CIPHER_H
+
+#include <cfg/compiler.h>
+#include <cfg/debug.h>
+
+typedef struct BlockCipher
+{
+	void (*set_key)(struct BlockCipher *c, const void *key);
+	void (*enc_block)(struct BlockCipher *c, void *block);
+	void (*dec_block)(struct BlockCipher *c, void *block);
+
+	void *buf;
+	uint8_t key_len;
+	uint8_t block_len;
+} BlockCipher;
+
+
+/**
+ * Return the key length (in bytes)
+ */
+INLINE size_t cipher_key_len(BlockCipher *c)
+{
+	return c->key_len;
+}
+
+/**
+ * Return the block length (in bytes)
+ */
+INLINE size_t cipher_block_len(BlockCipher *c)
+{
+	return c->block_len;
+}
+
+/**
+ * Set the current key used by the cipher.
+ *
+ * \note the buffer pointed by \a key is not modified and it is
+ * not needed anymore after this call returns.
+ */
+INLINE void cipher_set_key(BlockCipher *c, const void *key)
+{
+	ASSERT(c->set_key);
+	c->set_key(c, key);
+}
+
+/*********************************************************************************/
+/* ECB mode                                                                      */
+/*********************************************************************************/
+
+/**
+ * Encrypt a block (in-place) using the current key in ECB mode.
+ */
+INLINE void cipher_ecb_encrypt(BlockCipher *c, void *block)
+{
+	ASSERT(c->enc_block);
+	c->enc_block(c, block);
+}
+
+/**
+ * Decrypt a block (in-place) using the current key in ECB mode.
+ */
+INLINE void cipher_ecb_decrypt(BlockCipher *c, void *block)
+{
+	ASSERT(c->dec_block);
+	c->dec_block(c, block);
+}
+
+
+/*********************************************************************************/
+/* CBC mode                                                                      */
+/*********************************************************************************/
+
+/**
+ * Initialize CBC by setting the IV.
+ *
+ * \note the memory pointed by \a iv will be used and modified by the CBC
+ * functions. It is caller's responsibility to keep it available until there is
+ * no more CBC work to do.
+ */
+INLINE void cipher_cbc_begin(BlockCipher *c, void *iv)
+{
+	c->buf = ivbuf;
+}
+
+/**
+ * Encrypt a block (in-place) using the current key in CBC mode.
+ */
+void cipher_cbc_encrypt(BlockCipher *c, void *block);
+
+/**
+ * Decrypt a block (in-place) using the current key in CBC mode.
+ */
+void cipher_cbc_decrypt(BlockCipher *c, void *block);
+
+
+
+/*********************************************************************************/
+/* CTR mode                                                                      */
+/*********************************************************************************/
+
+/**
+ * Initialize CTR by setting the counter.
+ *
+ * \note the memory pointed by \a counter will be used and modified (incremented)
+ * by the CTR functions. It is caller's responsibility to keep it available until
+ * there is no more CTR work to do.
+ */
+INLINE void cipher_ctr_begin(BlockCipher *c, void *counter)
+{
+	c->buf = counter;
+}
+
+/**
+ * Encrypt a block (in-place) using the current key in CBC mode.
+ */
+void cipher_ctr_encrypt(BlockCipher *c, void *block);
+
+/**
+ * Decrypt a block (in-place) using the current key in CBC mode.
+ */
+void cipher_ctr_decrypt(BlockCipher *c, void *block);
+
+#endif /* SEC_CIPHER_H */
-- 
2.25.1