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* The MD2 hash function, described in RFC 1319.
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*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2003 Niels Mller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The nettle library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the nettle library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
/* This code originates from the Python Cryptography Toolkit, version 1.0.1.
Further hacked by Andreas Sigfridsson and Niels Mller */
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <assert.h>
#include <string.h>
#include "md2.h"
#include "macros.h"
static const uint8_t
S[256] = {
41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
31, 26, 219, 153, 141, 51, 159, 17, 131, 20
};
static void
md2_transform(struct md2_ctx *ctx, const uint8_t *data)
{
unsigned i;
uint8_t t;
memcpy(ctx->X + 16, data, MD2_DATA_SIZE);
for (i = 0, t = ctx->C[15];
i<MD2_DATA_SIZE; i++)
{
ctx->X[2 * MD2_DATA_SIZE + i]
= ctx->X[i] ^ ctx->X[MD2_DATA_SIZE + i];
t = (ctx->C[i] ^= S[data[i]^t]);
}
for (i = t = 0;
i< MD2_DATA_SIZE + 2;
t = (t + i) & 0xff, i++)
{
unsigned j;
for (j = 0; j < 3 * MD2_DATA_SIZE; j++)
t = (ctx->X[j] ^= S[t]);
}
}
#if 0
static void
md2_final(struct md2_ctx *ctx)
{
unsigned left = MD2_DATA_SIZE - ctx->index;
memset(ctx->block + ctx->index, left, left);
md2_transform(ctx, ctx->block);
}
#endif
void
md2_init(struct md2_ctx *ctx)
{
memset(ctx, 0, sizeof(*ctx));
}
void
md2_update(struct md2_ctx *ctx,
unsigned length,
const uint8_t *data)
{
if (ctx->index)
{
/* Try to fill partial block */
unsigned left = MD2_DATA_SIZE - ctx->index;
if (length < left)
{
memcpy(ctx->block + ctx->index, data, length);
ctx->index += length;
return; /* Finished */
}
else
{
memcpy(ctx->block + ctx->index, data, left);
md2_transform(ctx, ctx->block);
data += left;
length -= left;
}
}
while (length >= MD2_DATA_SIZE)
{
md2_transform(ctx, data);
data += MD2_DATA_SIZE;
length -= MD2_DATA_SIZE;
}
if ((ctx->index = length)) /* This assignment is intended */
/* Buffer leftovers */
memcpy(ctx->block, data, length);
}
void
md2_digest(struct md2_ctx *ctx,
unsigned length,
uint8_t *digest)
{
unsigned left;
assert(length <= MD2_DIGEST_SIZE);
left = MD2_DATA_SIZE - ctx->index;
memset(ctx->block + ctx->index, left, left);
md2_transform(ctx, ctx->block);
md2_transform(ctx, ctx->C);
memcpy(digest, ctx->X, length);
md2_init(ctx);
}