HGKeeper

* purple

* Purple is the legal property of its developers, whose names are too numerous

* to list here. Please refer to the COPYRIGHT file distributed with this

* source distribution.

* Original md4 taken from linux kernel

* MD4 Message Digest Algorithm (RFC1320).

* Implementation derived from Andrew Tridgell and Steve French's

* CIFS MD4 implementation, and the cryptoapi implementation

* originally based on the public domain implementation written

* by Colin Plumb in 1993.

* Copyright (c) Andrew Tridgell 1997-1998.

* Modified by Steve French (sfrench@us.ibm.com) 2002

* Copyright (c) Cryptoapi developers.

* This program 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 Street, Fifth Floor, Boston, MA 02111-1301 USA

#include <cipher.h>

#define MD4_DIGEST_SIZE 16

#define MD4_HMAC_BLOCK_SIZE 64

#define MD4_BLOCK_WORDS 16

#define MD4_HASH_WORDS 4

struct MD4_Context {

guint32 hash[MD4_HASH_WORDS];

guint32 block[MD4_BLOCK_WORDS];

guint64 byte_count;

};

static inline guint32 lshift(guint32 x, unsigned int s)

{

x &= 0xFFFFFFFF;

return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));

}

static inline guint32 F(guint32 x, guint32 y, guint32 z)

{

return (x & y) | ((~x) & z);

}

static inline guint32 G(guint32 x, guint32 y, guint32 z)

{

return (x & y) | (x & z) | (y & z);

}

static inline guint32 H(guint32 x, guint32 y, guint32 z)

{

return x ^ y ^ z;

}

#define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))

#define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (guint32)0x5A827999,s))

#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (guint32)0x6ED9EBA1,s))

static inline void le32_to_cpu_array(guint32 *buf, unsigned int words)

{

while (words--) {

*buf=GUINT_FROM_LE(*buf);

buf++;

}

static inline void cpu_to_le32_array(guint32 *buf, unsigned int words)

{

while (words--) {

*buf=GUINT_TO_LE(*buf);

buf++;

}

static void md4_transform(guint32 *hash, guint32 const *in)

{

guint32 a, b, c, d;

a = hash[0];

b = hash[1];

c = hash[2];

d = hash[3];

ROUND1(a, b, c, d, in[0], 3);

ROUND1(d, a, b, c, in[1], 7);

ROUND1(c, d, a, b, in[2], 11);

ROUND1(b, c, d, a, in[3], 19);

ROUND1(a, b, c, d, in[4], 3);

ROUND1(d, a, b, c, in[5], 7);

ROUND1(c, d, a, b, in[6], 11);

ROUND1(b, c, d, a, in[7], 19);

ROUND1(a, b, c, d, in[8], 3);

ROUND1(d, a, b, c, in[9], 7);

ROUND1(c, d, a, b, in[10], 11);

ROUND1(b, c, d, a, in[11], 19);

ROUND1(a, b, c, d, in[12], 3);

ROUND1(d, a, b, c, in[13], 7);

ROUND1(c, d, a, b, in[14], 11);

ROUND1(b, c, d, a, in[15], 19);

ROUND2(a, b, c, d,in[ 0], 3);

ROUND2(d, a, b, c, in[4], 5);

ROUND2(c, d, a, b, in[8], 9);

ROUND2(b, c, d, a, in[12], 13);

ROUND2(a, b, c, d, in[1], 3);

ROUND2(d, a, b, c, in[5], 5);

ROUND2(c, d, a, b, in[9], 9);

ROUND2(b, c, d, a, in[13], 13);

ROUND2(a, b, c, d, in[2], 3);

ROUND2(d, a, b, c, in[6], 5);

ROUND2(c, d, a, b, in[10], 9);

ROUND2(b, c, d, a, in[14], 13);

ROUND2(a, b, c, d, in[3], 3);

ROUND2(d, a, b, c, in[7], 5);

ROUND2(c, d, a, b, in[11], 9);

ROUND2(b, c, d, a, in[15], 13);

ROUND3(a, b, c, d,in[ 0], 3);

ROUND3(d, a, b, c, in[8], 9);

ROUND3(c, d, a, b, in[4], 11);

ROUND3(b, c, d, a, in[12], 15);

ROUND3(a, b, c, d, in[2], 3);

ROUND3(d, a, b, c, in[10], 9);

ROUND3(c, d, a, b, in[6], 11);

ROUND3(b, c, d, a, in[14], 15);

ROUND3(a, b, c, d, in[1], 3);

ROUND3(d, a, b, c, in[9], 9);

ROUND3(c, d, a, b, in[5], 11);

ROUND3(b, c, d, a, in[13], 15);

ROUND3(a, b, c, d, in[3], 3);

ROUND3(d, a, b, c, in[11], 9);

ROUND3(c, d, a, b, in[7], 11);

ROUND3(b, c, d, a, in[15], 15);

hash[0] += a;

hash[1] += b;

hash[2] += c;

hash[3] += d;

}

static inline void md4_transform_helper(struct MD4_Context *ctx)

{

le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(guint32));

md4_transform(ctx->hash, ctx->block);

}

static void

md4_init(PurpleCipherContext *context, gpointer extra) {

struct MD4_Context *mctx;

mctx = g_new0(struct MD4_Context, 1);

purple_cipher_context_set_data(context, mctx);

purple_cipher_context_reset(context, extra);

mctx->hash[0] = 0x67452301;

mctx->hash[1] = 0xefcdab89;

mctx->hash[2] = 0x98badcfe;

mctx->hash[3] = 0x10325476;

mctx->byte_count = 0;

}

static void

md4_reset(PurpleCipherContext *context, gpointer extra) {

struct MD4_Context *mctx;

mctx = purple_cipher_context_get_data(context);

mctx->hash[0] = 0x67452301;

mctx->hash[1] = 0xefcdab89;

mctx->hash[2] = 0x98badcfe;

mctx->hash[3] = 0x10325476;

mctx->byte_count = 0;

}

static void

md4_append(PurpleCipherContext *context, const guchar *data, size_t len)

{

struct MD4_Context *mctx = purple_cipher_context_get_data(context);

const guint32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);

mctx->byte_count += len;

if (avail > len) {

memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),

data, len);

return;

}

memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),

data, avail);

md4_transform_helper(mctx);

data += avail;

len -= avail;

while (len >= sizeof(mctx->block)) {

memcpy(mctx->block, data, sizeof(mctx->block));

md4_transform_helper(mctx);

data += sizeof(mctx->block);

len -= sizeof(mctx->block);

}

memcpy(mctx->block, data, len);

}

static gboolean

md4_digest(PurpleCipherContext *context, size_t in_len, guchar *out,

size_t *out_len)

{

struct MD4_Context *mctx = purple_cipher_context_get_data(context);

const unsigned int offset = mctx->byte_count & 0x3f;

char *p = (char *)mctx->block + offset;

int padding = 56 - (offset + 1);

if(in_len<16) return FALSE;

if(out_len) *out_len = 16;

*p++ = 0x80;

if (padding < 0) {

memset(p, 0x00, padding + sizeof (guint64));

md4_transform_helper(mctx);

p = (char *)mctx->block;

padding = 56;

}

memset(p, 0, padding);

mctx->block[14] = mctx->byte_count << 3;

mctx->block[15] = mctx->byte_count >> 29;

le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -

sizeof(guint64)) / sizeof(guint32));

md4_transform(mctx->hash, mctx->block);

cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(guint32));

memcpy(out, mctx->hash, sizeof(mctx->hash));

memset(mctx, 0, sizeof(*mctx));

return TRUE;

}

static void

md4_uninit(PurpleCipherContext *context) {

struct MD4_Context *md4_context;

purple_cipher_context_reset(context, NULL);

md4_context = purple_cipher_context_get_data(context);

memset(md4_context, 0, sizeof(*md4_context));

g_free(md4_context);

md4_context = NULL;

}

static size_t

md4_get_block_size(PurpleCipherContext *context)

{

/* This does not change (in this case) */

return MD4_HMAC_BLOCK_SIZE;

}

static PurpleCipherOps MD4Ops = {

NULL, /* Set option */

NULL, /* Get option */

md4_init, /* init */

md4_reset, /* reset */

md4_uninit, /* uninit */

NULL, /* set iv */

md4_append, /* append */

md4_digest, /* digest */

NULL, /* encrypt */

NULL, /* decrypt */

NULL, /* set salt */

NULL, /* get salt size */

NULL, /* set key */

NULL, /* get key size */

NULL, /* set batch mode */

NULL, /* get batch mode */

md4_get_block_size, /* get block size */

NULL /* set key with len */

};

PurpleCipherOps *

purple_md4_cipher_get_ops(void) {

return &MD4Ops;

}

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