linux/crypto/md4.c
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   1/* 
   2 * Cryptographic API.
   3 *
   4 * MD4 Message Digest Algorithm (RFC1320).
   5 *
   6 * Implementation derived from Andrew Tridgell and Steve French's
   7 * CIFS MD4 implementation, and the cryptoapi implementation
   8 * originally based on the public domain implementation written
   9 * by Colin Plumb in 1993.
  10 *
  11 * Copyright (c) Andrew Tridgell 1997-1998.
  12 * Modified by Steve French (sfrench@us.ibm.com) 2002
  13 * Copyright (c) Cryptoapi developers.
  14 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
  15 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  16 *
  17 * This program is free software; you can redistribute it and/or modify
  18 * it under the terms of the GNU General Public License as published by
  19 * the Free Software Foundation; either version 2 of the License, or
  20 * (at your option) any later version.
  21 *
  22 */
  23#include <crypto/internal/hash.h>
  24#include <linux/init.h>
  25#include <linux/kernel.h>
  26#include <linux/string.h>
  27#include <linux/types.h>
  28#include <asm/byteorder.h>
  29
  30#define MD4_DIGEST_SIZE         16
  31#define MD4_HMAC_BLOCK_SIZE     64
  32#define MD4_BLOCK_WORDS         16
  33#define MD4_HASH_WORDS          4
  34
  35struct md4_ctx {
  36        u32 hash[MD4_HASH_WORDS];
  37        u32 block[MD4_BLOCK_WORDS];
  38        u64 byte_count;
  39};
  40
  41static inline u32 lshift(u32 x, unsigned int s)
  42{
  43        x &= 0xFFFFFFFF;
  44        return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
  45}
  46
  47static inline u32 F(u32 x, u32 y, u32 z)
  48{
  49        return (x & y) | ((~x) & z);
  50}
  51
  52static inline u32 G(u32 x, u32 y, u32 z)
  53{
  54        return (x & y) | (x & z) | (y & z);
  55}
  56
  57static inline u32 H(u32 x, u32 y, u32 z)
  58{
  59        return x ^ y ^ z;
  60}
  61
  62#define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
  63#define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (u32)0x5A827999,s))
  64#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (u32)0x6ED9EBA1,s))
  65
  66/* XXX: this stuff can be optimized */
  67static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
  68{
  69        while (words--) {
  70                __le32_to_cpus(buf);
  71                buf++;
  72        }
  73}
  74
  75static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
  76{
  77        while (words--) {
  78                __cpu_to_le32s(buf);
  79                buf++;
  80        }
  81}
  82
  83static void md4_transform(u32 *hash, u32 const *in)
  84{
  85        u32 a, b, c, d;
  86
  87        a = hash[0];
  88        b = hash[1];
  89        c = hash[2];
  90        d = hash[3];
  91
  92        ROUND1(a, b, c, d, in[0], 3);
  93        ROUND1(d, a, b, c, in[1], 7);
  94        ROUND1(c, d, a, b, in[2], 11);
  95        ROUND1(b, c, d, a, in[3], 19);
  96        ROUND1(a, b, c, d, in[4], 3);
  97        ROUND1(d, a, b, c, in[5], 7);
  98        ROUND1(c, d, a, b, in[6], 11);
  99        ROUND1(b, c, d, a, in[7], 19);
 100        ROUND1(a, b, c, d, in[8], 3);
 101        ROUND1(d, a, b, c, in[9], 7);
 102        ROUND1(c, d, a, b, in[10], 11);
 103        ROUND1(b, c, d, a, in[11], 19);
 104        ROUND1(a, b, c, d, in[12], 3);
 105        ROUND1(d, a, b, c, in[13], 7);
 106        ROUND1(c, d, a, b, in[14], 11);
 107        ROUND1(b, c, d, a, in[15], 19);
 108
 109        ROUND2(a, b, c, d,in[ 0], 3);
 110        ROUND2(d, a, b, c, in[4], 5);
 111        ROUND2(c, d, a, b, in[8], 9);
 112        ROUND2(b, c, d, a, in[12], 13);
 113        ROUND2(a, b, c, d, in[1], 3);
 114        ROUND2(d, a, b, c, in[5], 5);
 115        ROUND2(c, d, a, b, in[9], 9);
 116        ROUND2(b, c, d, a, in[13], 13);
 117        ROUND2(a, b, c, d, in[2], 3);
 118        ROUND2(d, a, b, c, in[6], 5);
 119        ROUND2(c, d, a, b, in[10], 9);
 120        ROUND2(b, c, d, a, in[14], 13);
 121        ROUND2(a, b, c, d, in[3], 3);
 122        ROUND2(d, a, b, c, in[7], 5);
 123        ROUND2(c, d, a, b, in[11], 9);
 124        ROUND2(b, c, d, a, in[15], 13);
 125
 126        ROUND3(a, b, c, d,in[ 0], 3);
 127        ROUND3(d, a, b, c, in[8], 9);
 128        ROUND3(c, d, a, b, in[4], 11);
 129        ROUND3(b, c, d, a, in[12], 15);
 130        ROUND3(a, b, c, d, in[2], 3);
 131        ROUND3(d, a, b, c, in[10], 9);
 132        ROUND3(c, d, a, b, in[6], 11);
 133        ROUND3(b, c, d, a, in[14], 15);
 134        ROUND3(a, b, c, d, in[1], 3);
 135        ROUND3(d, a, b, c, in[9], 9);
 136        ROUND3(c, d, a, b, in[5], 11);
 137        ROUND3(b, c, d, a, in[13], 15);
 138        ROUND3(a, b, c, d, in[3], 3);
 139        ROUND3(d, a, b, c, in[11], 9);
 140        ROUND3(c, d, a, b, in[7], 11);
 141        ROUND3(b, c, d, a, in[15], 15);
 142
 143        hash[0] += a;
 144        hash[1] += b;
 145        hash[2] += c;
 146        hash[3] += d;
 147}
 148
 149static inline void md4_transform_helper(struct md4_ctx *ctx)
 150{
 151        le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
 152        md4_transform(ctx->hash, ctx->block);
 153}
 154
 155static int md4_init(struct shash_desc *desc)
 156{
 157        struct md4_ctx *mctx = shash_desc_ctx(desc);
 158
 159        mctx->hash[0] = 0x67452301;
 160        mctx->hash[1] = 0xefcdab89;
 161        mctx->hash[2] = 0x98badcfe;
 162        mctx->hash[3] = 0x10325476;
 163        mctx->byte_count = 0;
 164
 165        return 0;
 166}
 167
 168static int md4_update(struct shash_desc *desc, const u8 *data, unsigned int len)
 169{
 170        struct md4_ctx *mctx = shash_desc_ctx(desc);
 171        const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
 172
 173        mctx->byte_count += len;
 174
 175        if (avail > len) {
 176                memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 177                       data, len);
 178                return 0;
 179        }
 180
 181        memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 182               data, avail);
 183
 184        md4_transform_helper(mctx);
 185        data += avail;
 186        len -= avail;
 187
 188        while (len >= sizeof(mctx->block)) {
 189                memcpy(mctx->block, data, sizeof(mctx->block));
 190                md4_transform_helper(mctx);
 191                data += sizeof(mctx->block);
 192                len -= sizeof(mctx->block);
 193        }
 194
 195        memcpy(mctx->block, data, len);
 196
 197        return 0;
 198}
 199
 200static int md4_final(struct shash_desc *desc, u8 *out)
 201{
 202        struct md4_ctx *mctx = shash_desc_ctx(desc);
 203        const unsigned int offset = mctx->byte_count & 0x3f;
 204        char *p = (char *)mctx->block + offset;
 205        int padding = 56 - (offset + 1);
 206
 207        *p++ = 0x80;
 208        if (padding < 0) {
 209                memset(p, 0x00, padding + sizeof (u64));
 210                md4_transform_helper(mctx);
 211                p = (char *)mctx->block;
 212                padding = 56;
 213        }
 214
 215        memset(p, 0, padding);
 216        mctx->block[14] = mctx->byte_count << 3;
 217        mctx->block[15] = mctx->byte_count >> 29;
 218        le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
 219                          sizeof(u64)) / sizeof(u32));
 220        md4_transform(mctx->hash, mctx->block);
 221        cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
 222        memcpy(out, mctx->hash, sizeof(mctx->hash));
 223        memset(mctx, 0, sizeof(*mctx));
 224
 225        return 0;
 226}
 227
 228static struct shash_alg alg = {
 229        .digestsize     =       MD4_DIGEST_SIZE,
 230        .init           =       md4_init,
 231        .update         =       md4_update,
 232        .final          =       md4_final,
 233        .descsize       =       sizeof(struct md4_ctx),
 234        .base           =       {
 235                .cra_name       =       "md4",
 236                .cra_flags      =       CRYPTO_ALG_TYPE_SHASH,
 237                .cra_blocksize  =       MD4_HMAC_BLOCK_SIZE,
 238                .cra_module     =       THIS_MODULE,
 239        }
 240};
 241
 242static int __init md4_mod_init(void)
 243{
 244        return crypto_register_shash(&alg);
 245}
 246
 247static void __exit md4_mod_fini(void)
 248{
 249        crypto_unregister_shash(&alg);
 250}
 251
 252module_init(md4_mod_init);
 253module_exit(md4_mod_fini);
 254
 255MODULE_LICENSE("GPL");
 256MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
 257
 258
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