/*

* Cryptographic API.

*

* 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.

* Copyright (c) 2002 David S. Miller (davem@redhat.com)

* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>

*

* 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.

*

*/

#include <crypto/internal/hash.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/string.h>

#include <linux/types.h>

#include <asm/byteorder.h>

#define MD4_DIGEST_SIZE 16

#define MD4_HMAC_BLOCK_SIZE 64

#define MD4_BLOCK_WORDS 16

#define MD4_HASH_WORDS 4

struct md4_ctx {

};

static inline u32 lshift(u32 x, unsigned int s)

{

x &= 0xFFFFFFFF;

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

}

static inline u32 F(u32 x, u32 y, u32 z)

{

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

}

static inline u32 G(u32 x, u32 y, u32 z)

{

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

}

static inline u32 H(u32 x, u32 y, u32 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 + (u32)0x5A827999,s))

#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (u32)0x6ED9EBA1,s))

/* XXX: this stuff can be optimized */

static inline void le32_to_cpu_array(u32 *buf, unsigned int words)

{

while (words--) {

__le32_to_cpus(buf);

buf++;

}

}

static inline void cpu_to_le32_array(u32 *buf, unsigned int words)

{

while (words--) {

__cpu_to_le32s(buf);

buf++;

}

}

static void md4_transform(u32 *hash, u32 const *in)

{

u32 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_ctx *ctx)

{

le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));

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

}

static int md4_init(struct shash_desc *desc)

{

struct md4_ctx *mctx = shash_desc_ctx(desc);

mctx->hash[0] = 0x67452301;

mctx->hash[1] = 0xefcdab89;

mctx->hash[2] = 0x98badcfe;

mctx->hash[3] = 0x10325476;

mctx->byte_count = 0;

return 0;

}

static int md4_update(struct shash_desc *desc, const u8 *data, unsigned int len)

{

struct md4_ctx *mctx = shash_desc_ctx(desc);

const u32 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 0;

}

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);

return 0;

}

static int md4_final(struct shash_desc *desc, u8 *out)

{

struct md4_ctx *mctx = shash_desc_ctx(desc);

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

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

int padding = 56 - (offset + 1);

*p++ = 0x80;

if (padding < 0) {

memset(p, 0x00, padding + sizeof (u64));

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(u64)) / sizeof(u32));

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

cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));

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

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

return 0;

}

static struct shash_alg alg = {

.digestsize = MD4_DIGEST_SIZE,

.init = md4_init,

.update = md4_update,

.final = md4_final,

.descsize = sizeof(struct md4_ctx),

.base = {

.cra_name = "md4",

.cra_flags = CRYPTO_ALG_TYPE_SHASH,

.cra_blocksize = MD4_HMAC_BLOCK_SIZE,

.cra_module = THIS_MODULE,

}

};

static int __init md4_mod_init(void)

{

return crypto_register_shash(&alg);

}

static void __exit md4_mod_fini(void)

{

crypto_unregister_shash(&alg);

}

module_init(md4_mod_init);

module_exit(md4_mod_fini);

MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("MD4 Message Digest Algorithm");

MODULE_ALIAS_CRYPTO("md4");