89 lines
3.4 KiB
C
89 lines
3.4 KiB
C
/****************************************************************************
|
|
* libc/misc/lib_tea_encrypt.c
|
|
* Tiny Encryption Algorithm - Encryption support
|
|
*
|
|
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
*
|
|
* https://en.wikipedia.org/wiki/Tiny_Encryption_Algorithm: "Following is
|
|
* an adaptation of the reference encryption and decryption routines in C,
|
|
* released into the public domain by David Wheeler and Roger Needham."
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* 3. Neither the name NuttX nor the names of its contributors may be
|
|
* used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <stdint.h>
|
|
#include <nuttx/crypto/tea.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define TEA_KEY_SCHEDULE_CONSTANT 0x9e3779b9
|
|
#define TEA_SUM_SETUP_CONSTANT 0xc6ef3720
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: tea_encrypt
|
|
*
|
|
* Input Parameters:
|
|
* value = 2 x 32-bit value (input/output)
|
|
* key = 4 x 32-bit Cache key (input)
|
|
*
|
|
****************************************************************************/
|
|
|
|
void tea_encrypt(FAR uint32_t *value, FAR const uint32_t *key)
|
|
{
|
|
uint32_t v0 = value[0];
|
|
uint32_t v1 = value[1];
|
|
uint32_t sum = 0;
|
|
int i;
|
|
|
|
/* Basic cycle start */
|
|
|
|
for (i = 0; i < 32; i++)
|
|
{
|
|
sum += TEA_KEY_SCHEDULE_CONSTANT;
|
|
v0 += ((v1 << 4) + key[0]) ^ (v1 + sum) ^ ((v1 >> 5) + key[1]);
|
|
v1 += ((v0 << 4) + key[2]) ^ (v0 + sum) ^ ((v0 >> 5) + key[3]);
|
|
}
|
|
|
|
/* End cycle */
|
|
|
|
value[0] = v0;
|
|
value[1] = v1;
|
|
}
|