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/module.h>
  27#include <linux/string.h>
  28#include <linux/types.h>
  29#include <asm/byteorder.h>
  30
  31#define MD4_DIGEST_SIZE         16
  32#define MD4_HMAC_BLOCK_SIZE     64
  33#define MD4_BLOCK_WORDS         16
  34#define MD4_HASH_WORDS          4
  35
  36struct md4_ctx {
  37        u32 hash[MD4_HASH_WORDS];
  38        u32 block[MD4_BLOCK_WORDS];
  39        u64 byte_count;
  40};
  41
  42static inline u32 lshift(u32 x, unsigned int s)
  43{
  44        x &= 0xFFFFFFFF;
  45        return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
  46}
  47
  48static inline u32 F(u32 x, u32 y, u32 z)
  49{
  50        return (x & y) | ((~x) & z);
  51}
  52
  53static inline u32 G(u32 x, u32 y, u32 z)
  54{
  55        return (x & y) | (x & z) | (y & z);
  56}
  57
  58static inline u32 H(u32 x, u32 y, u32 z)
  59{
  60        return x ^ y ^ z;
  61}
  62
  63#define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
  64#define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (u32)0x5A827999,s))
  65#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (u32)0x6ED9EBA1,s))
  66
  67static void md4_transform(u32 *hash, u32 const *in)
  68{
  69        u32 a, b, c, d;
  70
  71        a = hash[0];
  72        b = hash[1];
  73        c = hash[2];
  74        d = hash[3];
  75
  76        ROUND1(a, b, c, d, in[0], 3);
  77        ROUND1(d, a, b, c, in[1], 7);
  78        ROUND1(c, d, a, b, in[2], 11);
  79        ROUND1(b, c, d, a, in[3], 19);
  80        ROUND1(a, b, c, d, in[4], 3);
  81        ROUND1(d, a, b, c, in[5], 7);
  82        ROUND1(c, d, a, b, in[6], 11);
  83        ROUND1(b, c, d, a, in[7], 19);
  84        ROUND1(a, b, c, d, in[8], 3);
  85        ROUND1(d, a, b, c, in[9], 7);
  86        ROUND1(c, d, a, b, in[10], 11);
  87        ROUND1(b, c, d, a, in[11], 19);
  88        ROUND1(a, b, c, d, in[12], 3);
  89        ROUND1(d, a, b, c, in[13], 7);
  90        ROUND1(c, d, a, b, in[14], 11);
  91        ROUND1(b, c, d, a, in[15], 19);
  92
  93        ROUND2(a, b, c, d,in[ 0], 3);
  94        ROUND2(d, a, b, c, in[4], 5);
  95        ROUND2(c, d, a, b, in[8], 9);
  96        ROUND2(b, c, d, a, in[12], 13);
  97        ROUND2(a, b, c, d, in[1], 3);
  98        ROUND2(d, a, b, c, in[5], 5);
  99        ROUND2(c, d, a, b, in[9], 9);
 100        ROUND2(b, c, d, a, in[13], 13);
 101        ROUND2(a, b, c, d, in[2], 3);
 102        ROUND2(d, a, b, c, in[6], 5);
 103        ROUND2(c, d, a, b, in[10], 9);
 104        ROUND2(b, c, d, a, in[14], 13);
 105        ROUND2(a, b, c, d, in[3], 3);
 106        ROUND2(d, a, b, c, in[7], 5);
 107        ROUND2(c, d, a, b, in[11], 9);
 108        ROUND2(b, c, d, a, in[15], 13);
 109
 110        ROUND3(a, b, c, d,in[ 0], 3);
 111        ROUND3(d, a, b, c, in[8], 9);
 112        ROUND3(c, d, a, b, in[4], 11);
 113        ROUND3(b, c, d, a, in[12], 15);
 114        ROUND3(a, b, c, d, in[2], 3);
 115        ROUND3(d, a, b, c, in[10], 9);
 116        ROUND3(c, d, a, b, in[6], 11);
 117        ROUND3(b, c, d, a, in[14], 15);
 118        ROUND3(a, b, c, d, in[1], 3);
 119        ROUND3(d, a, b, c, in[9], 9);
 120        ROUND3(c, d, a, b, in[5], 11);
 121        ROUND3(b, c, d, a, in[13], 15);
 122        ROUND3(a, b, c, d, in[3], 3);
 123        ROUND3(d, a, b, c, in[11], 9);
 124        ROUND3(c, d, a, b, in[7], 11);
 125        ROUND3(b, c, d, a, in[15], 15);
 126
 127        hash[0] += a;
 128        hash[1] += b;
 129        hash[2] += c;
 130        hash[3] += d;
 131}
 132
 133static inline void md4_transform_helper(struct md4_ctx *ctx)
 134{
 135        le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
 136        md4_transform(ctx->hash, ctx->block);
 137}
 138
 139static int md4_init(struct shash_desc *desc)
 140{
 141        struct md4_ctx *mctx = shash_desc_ctx(desc);
 142
 143        mctx->hash[0] = 0x67452301;
 144        mctx->hash[1] = 0xefcdab89;
 145        mctx->hash[2] = 0x98badcfe;
 146        mctx->hash[3] = 0x10325476;
 147        mctx->byte_count = 0;
 148
 149        return 0;
 150}
 151
 152static int md4_update(struct shash_desc *desc, const u8 *data, unsigned int len)
 153{
 154        struct md4_ctx *mctx = shash_desc_ctx(desc);
 155        const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
 156
 157        mctx->byte_count += len;
 158
 159        if (avail > len) {
 160                memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 161                       data, len);
 162                return 0;
 163        }
 164
 165        memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 166               data, avail);
 167
 168        md4_transform_helper(mctx);
 169        data += avail;
 170        len -= avail;
 171
 172        while (len >= sizeof(mctx->block)) {
 173                memcpy(mctx->block, data, sizeof(mctx->block));
 174                md4_transform_helper(mctx);
 175                data += sizeof(mctx->block);
 176                len -= sizeof(mctx->block);
 177        }
 178
 179        memcpy(mctx->block, data, len);
 180
 181        return 0;
 182}
 183
 184static int md4_final(struct shash_desc *desc, u8 *out)
 185{
 186        struct md4_ctx *mctx = shash_desc_ctx(desc);
 187        const unsigned int offset = mctx->byte_count & 0x3f;
 188        char *p = (char *)mctx->block + offset;
 189        int padding = 56 - (offset + 1);
 190
 191        *p++ = 0x80;
 192        if (padding < 0) {
 193                memset(p, 0x00, padding + sizeof (u64));
 194                md4_transform_helper(mctx);
 195                p = (char *)mctx->block;
 196                padding = 56;
 197        }
 198
 199        memset(p, 0, padding);
 200        mctx->block[14] = mctx->byte_count << 3;
 201        mctx->block[15] = mctx->byte_count >> 29;
 202        le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
 203                          sizeof(u64)) / sizeof(u32));
 204        md4_transform(mctx->hash, mctx->block);
 205        cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
 206        memcpy(out, mctx->hash, sizeof(mctx->hash));
 207        memset(mctx, 0, sizeof(*mctx));
 208
 209        return 0;
 210}
 211
 212static struct shash_alg alg = {
 213        .digestsize     =       MD4_DIGEST_SIZE,
 214        .init           =       md4_init,
 215        .update         =       md4_update,
 216        .final          =       md4_final,
 217        .descsize       =       sizeof(struct md4_ctx),
 218        .base           =       {
 219                .cra_name        =      "md4",
 220                .cra_driver_name =      "md4-generic",
 221                .cra_blocksize   =      MD4_HMAC_BLOCK_SIZE,
 222                .cra_module      =      THIS_MODULE,
 223        }
 224};
 225
 226static int __init md4_mod_init(void)
 227{
 228        return crypto_register_shash(&alg);
 229}
 230
 231static void __exit md4_mod_fini(void)
 232{
 233        crypto_unregister_shash(&alg);
 234}
 235
 236subsys_initcall(md4_mod_init);
 237module_exit(md4_mod_fini);
 238
 239MODULE_LICENSE("GPL");
 240MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
 241MODULE_ALIAS_CRYPTO("md4");
 242
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