/*
* Copyright (C) 2006-2010 Vincent Hanquez <vincent@snarc.org>
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <string.h>
#include "cryptonite_skein.h"
#include "cryptonite_skein512.h"
#include "cryptonite_bitfn.h"
#include "cryptonite_align.h"
static const uint8_t K512_0[4] = { 46, 36, 19, 37, };
static const uint8_t K512_1[4] = { 33, 27, 14, 42, };
static const uint8_t K512_2[4] = { 17, 49, 36, 39, };
static const uint8_t K512_3[4] = { 44, 9, 54, 56, };
static const uint8_t K512_4[4] = { 39, 30, 34, 24, };
static const uint8_t K512_5[4] = { 13, 50, 10, 17, };
static const uint8_t K512_6[4] = { 25, 29, 39, 43, };
static const uint8_t K512_7[4] = { 8, 35, 56, 22, };
static inline void skein512_do_chunk(struct skein512_ctx *ctx, uint64_t *buf, uint32_t len)
{
uint64_t x[8];
uint64_t ts[3];
uint64_t ks[8+1];
ks[8] = 0x1bd11bdaa9fc1a22ULL;
ks[0] = ctx->h[0]; ks[8] ^= ctx->h[0];
ks[1] = ctx->h[1]; ks[8] ^= ctx->h[1];
ks[2] = ctx->h[2]; ks[8] ^= ctx->h[2];
ks[3] = ctx->h[3]; ks[8] ^= ctx->h[3];
ks[4] = ctx->h[4]; ks[8] ^= ctx->h[4];
ks[5] = ctx->h[5]; ks[8] ^= ctx->h[5];
ks[6] = ctx->h[6]; ks[8] ^= ctx->h[6];
ks[7] = ctx->h[7]; ks[8] ^= ctx->h[7];
ts[0] = ctx->t0;
ts[1] = ctx->t1;
ts[0] += len;
ts[2] = ts[0] ^ ts[1];
#define INJECTKEY(r) \
x[0] += ks[((r)+0) % (8+1)]; \
x[1] += ks[((r)+1) % (8+1)]; \
x[2] += ks[((r)+2) % (8+1)]; \
x[3] += ks[((r)+3) % (8+1)]; \
x[4] += ks[((r)+4) % (8+1)]; \
x[5] += ks[((r)+5) % (8+1)] + ts[((r)+0) % 3]; \
x[6] += ks[((r)+6) % (8+1)] + ts[((r)+1) % 3]; \
x[7] += ks[((r)+7) % (8+1)] + (r)
#define ROUND(a,b,c,d,e,f,g,h,k) \
x[a] += x[b]; x[b] = rol64(x[b],k[0]); x[b] ^= x[a]; \
x[c] += x[d]; x[d] = rol64(x[d],k[1]); x[d] ^= x[c]; \
x[e] += x[f]; x[f] = rol64(x[f],k[2]); x[f] ^= x[e]; \
x[g] += x[h]; x[h] = rol64(x[h],k[3]); x[h] ^= x[g];
#define PASS(i) \
ROUND(0,1,2,3,4,5,6,7,K512_0); \
ROUND(2,1,4,7,6,5,0,3,K512_1); \
ROUND(4,1,6,3,0,5,2,7,K512_2); \
ROUND(6,1,0,7,2,5,4,3,K512_3); \
INJECTKEY((i*2) + 1); \
ROUND(0,1,2,3,4,5,6,7,K512_4); \
ROUND(2,1,4,7,6,5,0,3,K512_5); \
ROUND(4,1,6,3,0,5,2,7,K512_6); \
ROUND(6,1,0,7,2,5,4,3,K512_7); \
INJECTKEY((i*2) + 2)
x[0] = le64_to_cpu(buf[0]) + ks[0];
x[1] = le64_to_cpu(buf[1]) + ks[1];
x[2] = le64_to_cpu(buf[2]) + ks[2];
x[3] = le64_to_cpu(buf[3]) + ks[3];
x[4] = le64_to_cpu(buf[4]) + ks[4];
x[5] = le64_to_cpu(buf[5]) + ks[5] + ts[0];
x[6] = le64_to_cpu(buf[6]) + ks[6] + ts[1];
x[7] = le64_to_cpu(buf[7]) + ks[7];
/* 9 pass of 8 rounds = 72 rounds */
PASS(0);
PASS(1);
PASS(2);
PASS(3);
PASS(4);
PASS(5);
PASS(6);
PASS(7);
PASS(8);
ts[1] &= ~FLAG_FIRST;
ctx->t0 = ts[0];
ctx->t1 = ts[1];
ctx->h[0] = x[0] ^ cpu_to_le64(buf[0]);
ctx->h[1] = x[1] ^ cpu_to_le64(buf[1]);
ctx->h[2] = x[2] ^ cpu_to_le64(buf[2]);
ctx->h[3] = x[3] ^ cpu_to_le64(buf[3]);
ctx->h[4] = x[4] ^ cpu_to_le64(buf[4]);
ctx->h[5] = x[5] ^ cpu_to_le64(buf[5]);
ctx->h[6] = x[6] ^ cpu_to_le64(buf[6]);
ctx->h[7] = x[7] ^ cpu_to_le64(buf[7]);
}
void cryptonite_skein512_init(struct skein512_ctx *ctx, uint32_t hashlen)
{
uint64_t buf[8];
memset(ctx, 0, sizeof(*ctx));
SET_TYPE(ctx, FLAG_FIRST | FLAG_FINAL | FLAG_TYPE(TYPE_CFG));
memset(buf, '\0', sizeof(buf));
buf[0] = cpu_to_le64((SKEIN_VERSION << 32) | SKEIN_IDSTRING);
buf[1] = cpu_to_le64(hashlen);
buf[2] = 0; /* tree info, not implemented */
skein512_do_chunk(ctx, buf, 4*8);
SET_TYPE(ctx, FLAG_FIRST | FLAG_TYPE(TYPE_MSG));
}
void cryptonite_skein512_update(struct skein512_ctx *ctx, const uint8_t *data, uint32_t len)
{
uint32_t to_fill;
if (!len)
return;
to_fill = 64 - ctx->bufindex;
if (ctx->bufindex == 64) {
skein512_do_chunk(ctx, (uint64_t *) ctx->buf, 64);
ctx->bufindex = 0;
}
/* process partial buffer if there's enough data to make a block
* and there's without doubt further blocks */
if (ctx->bufindex && len > to_fill) {
memcpy(ctx->buf + ctx->bufindex, data, to_fill);
skein512_do_chunk(ctx, (uint64_t *) ctx->buf, 64);
len -= to_fill;
data += to_fill;
ctx->bufindex = 0;
}
if (need_alignment(data, 8)) {
uint64_t tramp[8];
ASSERT_ALIGNMENT(tramp, 8);
for (; len > 64; len -= 64, data += 64) {
memcpy(tramp, data, 64);
skein512_do_chunk(ctx, tramp, 64);
}
} else {
/* process as much 64-block as possible except the last one in case we finalize */
for (; len > 64; len -= 64, data += 64)
skein512_do_chunk(ctx, (uint64_t *) data, 64);
}
/* append data into buf */
if (len) {
memcpy(ctx->buf + ctx->bufindex, data, len);
ctx->bufindex += len;
}
}
void cryptonite_skein512_finalize(struct skein512_ctx *ctx, uint32_t hashlen, uint8_t *out)
{
uint32_t outsize;
uint64_t *p = (uint64_t *) out;
uint64_t x[8];
int i, j, n;
ctx->t1 |= FLAG_FINAL;
/* if buf is not complete pad with 0 bytes */
if (ctx->bufindex < 64)
memset(ctx->buf + ctx->bufindex, '\0', 64 - ctx->bufindex);
skein512_do_chunk(ctx, (uint64_t *) ctx->buf, ctx->bufindex);
memset(ctx->buf, '\0', 64);
/* make sure we have a 8 bit rounded value */
outsize = (hashlen + 7) >> 3;
/* backup h[0--7] */
for (j = 0; j < 8; j++)
x[j] = ctx->h[j];
/* threefish in counter mode, 0 for 1st 64 bytes, 1 for 2nd 64 bytes, .. */
for (i = 0; i*64 < outsize; i++) {
uint64_t w[8];
*((uint64_t *) ctx->buf) = cpu_to_le64(i);
SET_TYPE(ctx, FLAG_FIRST | FLAG_FINAL | FLAG_TYPE(TYPE_OUT));
skein512_do_chunk(ctx, (uint64_t *) ctx->buf, sizeof(uint64_t));
n = outsize - i * 64;
if (n >= 64) n = 64;
cpu_to_le64_array(w, ctx->h, 8);
memcpy(out + i*64, w, n);
/* restore h[0--7] */
for (j = 0; j < 8; j++)
ctx->h[j] = x[j];
}
}