mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-04-24 15:31:56 -04:00
252 lines
6 KiB
C
252 lines
6 KiB
C
/* chacha.c
|
|
*
|
|
* Copyright (C) 2006-2015 wolfSSL Inc.
|
|
*
|
|
* This file is part of wolfSSL. (formerly known as CyaSSL)
|
|
*
|
|
* wolfSSL 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.
|
|
*
|
|
* wolfSSL 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 Street, Fifth Floor, Boston, MA 02110-1301, USA
|
|
*
|
|
* based from
|
|
* chacha-ref.c version 20080118
|
|
* D. J. Bernstein
|
|
* Public domain.
|
|
*/
|
|
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include <config.h>
|
|
#endif
|
|
|
|
#include <wolfssl/wolfcrypt/settings.h>
|
|
|
|
#ifdef HAVE_CHACHA
|
|
|
|
#include <wolfssl/wolfcrypt/chacha.h>
|
|
#include <wolfssl/wolfcrypt/error-crypt.h>
|
|
#include <wolfssl/wolfcrypt/logging.h>
|
|
#ifdef NO_INLINE
|
|
#include <wolfssl/wolfcrypt/misc.h>
|
|
#else
|
|
#include <wolfcrypt/src/misc.c>
|
|
#endif
|
|
|
|
#ifdef CHACHA_AEAD_TEST
|
|
#include <stdio.h>
|
|
#endif
|
|
|
|
#ifdef BIG_ENDIAN_ORDER
|
|
#define LITTLE32(x) ByteReverseWord32(x)
|
|
#else
|
|
#define LITTLE32(x) (x)
|
|
#endif
|
|
|
|
/* Number of rounds */
|
|
#define ROUNDS 20
|
|
|
|
#define U32C(v) (v##U)
|
|
#define U32V(v) ((word32)(v) & U32C(0xFFFFFFFF))
|
|
#define U8TO32_LITTLE(p) LITTLE32(((word32*)(p))[0])
|
|
|
|
#define ROTATE(v,c) rotlFixed(v, c)
|
|
#define XOR(v,w) ((v) ^ (w))
|
|
#define PLUS(v,w) (U32V((v) + (w)))
|
|
#define PLUSONE(v) (PLUS((v),1))
|
|
|
|
#define QUARTERROUND(a,b,c,d) \
|
|
x[a] = PLUS(x[a],x[b]); x[d] = ROTATE(XOR(x[d],x[a]),16); \
|
|
x[c] = PLUS(x[c],x[d]); x[b] = ROTATE(XOR(x[b],x[c]),12); \
|
|
x[a] = PLUS(x[a],x[b]); x[d] = ROTATE(XOR(x[d],x[a]), 8); \
|
|
x[c] = PLUS(x[c],x[d]); x[b] = ROTATE(XOR(x[b],x[c]), 7);
|
|
|
|
|
|
/**
|
|
* Set up iv(nonce). Earlier versions used 64 bits instead of 96, this version
|
|
* uses the typical AEAD 96 bit nonce and can do record sizes of 256 GB.
|
|
*/
|
|
int wc_Chacha_SetIV(ChaCha* ctx, const byte* inIv, word32 counter)
|
|
{
|
|
word32 temp[3]; /* used for alignment of memory */
|
|
|
|
#ifdef CHACHA_AEAD_TEST
|
|
word32 i;
|
|
printf("NONCE : ");
|
|
for (i = 0; i < 12; i++) {
|
|
printf("%02x", inIv[i]);
|
|
}
|
|
printf("\n\n");
|
|
#endif
|
|
|
|
if (ctx == NULL)
|
|
return BAD_FUNC_ARG;
|
|
|
|
XMEMCPY(temp, inIv, 12);
|
|
|
|
ctx->X[12] = LITTLE32(counter); /* block counter */
|
|
ctx->X[13] = LITTLE32(temp[0]); /* fixed variable from nonce */
|
|
ctx->X[14] = LITTLE32(temp[1]); /* counter from nonce */
|
|
ctx->X[15] = LITTLE32(temp[2]); /* counter from nonce */
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* "expand 32-byte k" as unsigned 32 byte */
|
|
static const word32 sigma[4] = {0x61707865, 0x3320646e, 0x79622d32, 0x6b206574};
|
|
/* "expand 16-byte k" as unsigned 16 byte */
|
|
static const word32 tau[4] = {0x61707865, 0x3120646e, 0x79622d36, 0x6b206574};
|
|
|
|
/**
|
|
* Key setup. 8 word iv (nonce)
|
|
*/
|
|
int wc_Chacha_SetKey(ChaCha* ctx, const byte* key, word32 keySz)
|
|
{
|
|
const word32* constants;
|
|
const byte* k;
|
|
|
|
#ifdef XSTREAM_ALIGN
|
|
word32 alignKey[8];
|
|
#endif
|
|
|
|
if (ctx == NULL)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (keySz != 16 && keySz != 32)
|
|
return BAD_FUNC_ARG;
|
|
|
|
#ifdef XSTREAM_ALIGN
|
|
if ((wolfssl_word)key % 4) {
|
|
WOLFSSL_MSG("wc_ChachaSetKey unaligned key");
|
|
XMEMCPY(alignKey, key, keySz);
|
|
k = (byte*)alignKey;
|
|
}
|
|
else {
|
|
k = key;
|
|
}
|
|
#else
|
|
k = key;
|
|
#endif /* XSTREAM_ALIGN */
|
|
|
|
#ifdef CHACHA_AEAD_TEST
|
|
word32 i;
|
|
printf("ChaCha key used :\n");
|
|
for (i = 0; i < keySz; i++) {
|
|
printf("%02x", key[i]);
|
|
if ((i + 1) % 8 == 0)
|
|
printf("\n");
|
|
}
|
|
printf("\n\n");
|
|
#endif
|
|
|
|
ctx->X[4] = U8TO32_LITTLE(k + 0);
|
|
ctx->X[5] = U8TO32_LITTLE(k + 4);
|
|
ctx->X[6] = U8TO32_LITTLE(k + 8);
|
|
ctx->X[7] = U8TO32_LITTLE(k + 12);
|
|
if (keySz == 32) {
|
|
k += 16;
|
|
constants = sigma;
|
|
}
|
|
else {
|
|
constants = tau;
|
|
}
|
|
ctx->X[ 8] = U8TO32_LITTLE(k + 0);
|
|
ctx->X[ 9] = U8TO32_LITTLE(k + 4);
|
|
ctx->X[10] = U8TO32_LITTLE(k + 8);
|
|
ctx->X[11] = U8TO32_LITTLE(k + 12);
|
|
ctx->X[ 0] = constants[0];
|
|
ctx->X[ 1] = constants[1];
|
|
ctx->X[ 2] = constants[2];
|
|
ctx->X[ 3] = constants[3];
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Converts word into bytes with rotations having been done.
|
|
*/
|
|
static INLINE void wc_Chacha_wordtobyte(word32 output[16], const word32 input[16])
|
|
{
|
|
word32 x[16];
|
|
word32 i;
|
|
|
|
for (i = 0; i < 16; i++) {
|
|
x[i] = input[i];
|
|
}
|
|
|
|
for (i = (ROUNDS); i > 0; i -= 2) {
|
|
QUARTERROUND(0, 4, 8, 12)
|
|
QUARTERROUND(1, 5, 9, 13)
|
|
QUARTERROUND(2, 6, 10, 14)
|
|
QUARTERROUND(3, 7, 11, 15)
|
|
QUARTERROUND(0, 5, 10, 15)
|
|
QUARTERROUND(1, 6, 11, 12)
|
|
QUARTERROUND(2, 7, 8, 13)
|
|
QUARTERROUND(3, 4, 9, 14)
|
|
}
|
|
|
|
for (i = 0; i < 16; i++) {
|
|
x[i] = PLUS(x[i], input[i]);
|
|
}
|
|
|
|
for (i = 0; i < 16; i++) {
|
|
output[i] = LITTLE32(x[i]);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Encrypt a stream of bytes
|
|
*/
|
|
static void wc_Chacha_encrypt_bytes(ChaCha* ctx, const byte* m, byte* c,
|
|
word32 bytes)
|
|
{
|
|
byte* output;
|
|
word32 temp[16]; /* used to make sure aligned */
|
|
word32 i;
|
|
|
|
output = (byte*)temp;
|
|
|
|
if (!bytes) return;
|
|
for (;;) {
|
|
wc_Chacha_wordtobyte(temp, ctx->X);
|
|
ctx->X[12] = PLUSONE(ctx->X[12]);
|
|
if (bytes <= 64) {
|
|
for (i = 0; i < bytes; ++i) {
|
|
c[i] = m[i] ^ output[i];
|
|
}
|
|
return;
|
|
}
|
|
for (i = 0; i < 64; ++i) {
|
|
c[i] = m[i] ^ output[i];
|
|
}
|
|
bytes -= 64;
|
|
c += 64;
|
|
m += 64;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* API to encrypt/decrypt a message of any size.
|
|
*/
|
|
int wc_Chacha_Process(ChaCha* ctx, byte* output, const byte* input, word32 msglen)
|
|
{
|
|
if (ctx == NULL)
|
|
return BAD_FUNC_ARG;
|
|
|
|
wc_Chacha_encrypt_bytes(ctx, input, output, msglen);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif /* HAVE_CHACHA*/
|
|
|