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
  67/* XXX: this stuff can be optimized */
  68static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
  69{
  70        while (words--) {
  71                __le32_to_cpus(buf);
  72                buf++;
  73        }
  74}
  75
  76static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
  77{
  78        while (words--) {
  79                __cpu_to_le32s(buf);
  80                buf++;
  81        }
  82}
  83
  84static void md4_transform(u32 *hash, u32 const *in)
  85{
  86        u32 a, b, c, d;
  87
  88        a = hash[0];
  89        b = hash[1];
  90        c = hash[2];
  91        d = hash[3];
  92
  93        ROUND1(a, b, c, d, in[0], 3);
  94        ROUND1(d, a, b, c, in[1], 7);
  95        ROUND1(c, d, a, b, in[2], 11);
  96        ROUND1(b, c, d, a, in[3], 19);
  97        ROUND1(a, b, c, d, in[4], 3);
  98        ROUND1(d, a, b, c, in[5], 7);
  99        ROUND1(c, d, a, b, in[6], 11);
 100        ROUND1(b, c, d, a, in[7], 19);
 101        ROUND1(a, b, c, d, in[8], 3);
 102        ROUND1(d, a, b, c, in[9], 7);
 103        ROUND1(c, d, a, b, in[10], 11);
 104        ROUND1(b, c, d, a, in[11], 19);
 105        ROUND1(a, b, c, d, in[12], 3);
 106        ROUND1(d, a, b, c, in[13], 7);
 107        ROUND1(c, d, a, b, in[14], 11);
 108        ROUND1(b, c, d, a, in[15], 19);
 109
 110        ROUND2(a, b, c, d,in[ 0], 3);
 111        ROUND2(d, a, b, c, in[4], 5);
 112        ROUND2(c, d, a, b, in[8], 9);
 113        ROUND2(b, c, d, a, in[12], 13);
 114        ROUND2(a, b, c, d, in[1], 3);
 115        ROUND2(d, a, b, c, in[5], 5);
 116        ROUND2(c, d, a, b, in[9], 9);
 117        ROUND2(b, c, d, a, in[13], 13);
 118        ROUND2(a, b, c, d, in[2], 3);
 119        ROUND2(d, a, b, c, in[6], 5);
 120        ROUND2(c, d, a, b, in[10], 9);
 121        ROUND2(b, c, d, a, in[14], 13);
 122        ROUND2(a, b, c, d, in[3], 3);
 123        ROUND2(d, a, b, c, in[7], 5);
 124        ROUND2(c, d, a, b, in[11], 9);
 125        ROUND2(b, c, d, a, in[15], 13);
 126
 127        ROUND3(a, b, c, d,in[ 0], 3);
 128        ROUND3(d, a, b, c, in[8], 9);
 129        ROUND3(c, d, a, b, in[4], 11);
 130        ROUND3(b, c, d, a, in[12], 15);
 131        ROUND3(a, b, c, d, in[2], 3);
 132        ROUND3(d, a, b, c, in[10], 9);
 133        ROUND3(c, d, a, b, in[6], 11);
 134        ROUND3(b, c, d, a, in[14], 15);
 135        ROUND3(a, b, c, d, in[1], 3);
 136        ROUND3(d, a, b, c, in[9], 9);
 137        ROUND3(c, d, a, b, in[5], 11);
 138        ROUND3(b, c, d, a, in[13], 15);
 139        ROUND3(a, b, c, d, in[3], 3);
 140        ROUND3(d, a, b, c, in[11], 9);
 141        ROUND3(c, d, a, b, in[7], 11);
 142        ROUND3(b, c, d, a, in[15], 15);
 143
 144        hash[0] += a;
 145        hash[1] += b;
 146        hash[2] += c;
 147        hash[3] += d;
 148}
 149
 150static inline void md4_transform_helper(struct md4_ctx *ctx)
 151{
 152        le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
 153        md4_transform(ctx->hash, ctx->block);
 154}
 155
 156static int md4_init(struct shash_desc *desc)
 157{
 158        struct md4_ctx *mctx = shash_desc_ctx(desc);
 159
 160        mctx->hash[0] = 0x67452301;
 161        mctx->hash[1] = 0xefcdab89;
 162        mctx->hash[2] = 0x98badcfe;
 163        mctx->hash[3] = 0x10325476;
 164        mctx->byte_count = 0;
 165
 166        return 0;
 167}
 168
 169static int md4_update(struct shash_desc *desc, const u8 *data, unsigned int len)
 170{
 171        struct md4_ctx *mctx = shash_desc_ctx(desc);
 172        const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
 173
 174        mctx->byte_count += len;
 175
 176        if (avail > len) {
 177                memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 178                       data, len);
 179                return 0;
 180        }
 181
 182        memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 183               data, avail);
 184
 185        md4_transform_helper(mctx);
 186        data += avail;
 187        len -= avail;
 188
 189        while (len >= sizeof(mctx->block)) {
 190                memcpy(mctx->block, data, sizeof(mctx->block));
 191                md4_transform_helper(mctx);
 192                data += sizeof(mctx->block);
 193                len -= sizeof(mctx->block);
 194        }
 195
 196        memcpy(mctx->block, data, len);
 197
 198        return 0;
 199}
 200
 201static int md4_final(struct shash_desc *desc, u8 *out)
 202{
 203        struct md4_ctx *mctx = shash_desc_ctx(desc);
 204        const unsigned int offset = mctx->byte_count & 0x3f;
 205        char *p = (char *)mctx->block + offset;
 206        int padding = 56 - (offset + 1);
 207
 208        *p++ = 0x80;
 209        if (padding < 0) {
 210                memset(p, 0x00, padding + sizeof (u64));
 211                md4_transform_helper(mctx);
 212                p = (char *)mctx->block;
 213                padding = 56;
 214        }
 215
 216        memset(p, 0, padding);
 217        mctx->block[14] = mctx->byte_count << 3;
 218        mctx->block[15] = mctx->byte_count >> 29;
 219        le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
 220                          sizeof(u64)) / sizeof(u32));
 221        md4_transform(mctx->hash, mctx->block);
 222        cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
 223        memcpy(out, mctx->hash, sizeof(mctx->hash));
 224        memset(mctx, 0, sizeof(*mctx));
 225
 226        return 0;
 227}
 228
 229static struct shash_alg alg = {
 230        .digestsize     =       MD4_DIGEST_SIZE,
 231        .init           =       md4_init,
 232        .update         =       md4_update,
 233        .final          =       md4_final,
 234        .descsize       =       sizeof(struct md4_ctx),
 235        .base           =       {
 236                .cra_name       =       "md4",
 237                .cra_flags      =       CRYPTO_ALG_TYPE_SHASH,
 238                .cra_blocksize  =       MD4_HMAC_BLOCK_SIZE,
 239                .cra_module     =       THIS_MODULE,
 240        }
 241};
 242
 243static int __init md4_mod_init(void)
 244{
 245        return crypto_register_shash(&alg);
 246}
 247
 248static void __exit md4_mod_fini(void)
 249{
 250        crypto_unregister_shash(&alg);
 251}
 252
 253module_init(md4_mod_init);
 254module_exit(md4_mod_fini);
 255
 256MODULE_LICENSE("GPL");
 257MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
 258
 259
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