crypto/md4.c

   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 <linux/init.h>
  24 #include <linux/crypto.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
  35 struct md4_ctx {
  36         u32 hash[MD4_HASH_WORDS];
  37         u32 block[MD4_BLOCK_WORDS];
  38         u64 byte_count;
  39 };
  40
  41 static inline u32 lshift(u32 x, unsigned int s)
  42 {
  43         x &= 0xFFFFFFFF;
  44         return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
  45 }
  46
  47 static inline u32 F(u32 x, u32 y, u32 z)
  48 {
  49         return (x & y) | ((~x) & z);
  50 }
  51
  52 static inline u32 G(u32 x, u32 y, u32 z)
  53 {
  54         return (x & y) | (x & z) | (y & z);
  55 }
  56
  57 static 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 */
  67 static 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
  75 static 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
  83 static 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
 149 static inline void md4_transform_helper(struct md4_ctx *ctx)
 150 {
 151         le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
 152         md4_transform(ctx->hash, ctx->block);
 153 }
 154
 155 static void md4_init(struct crypto_tfm *tfm)
 156 {
 157         struct md4_ctx *mctx = crypto_tfm_ctx(tfm);
 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
 166 static void md4_update(struct crypto_tfm *tfm, const u8 *data, unsigned int len)
 167 {
 168         struct md4_ctx *mctx = crypto_tfm_ctx(tfm);
 169         const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
 170
 171         mctx->byte_count += len;
 172
 173         if (avail > len) {
 174                 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 175                        data, len);
 176                 return;
 177         }
 178
 179         memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 180                data, avail);
 181
 182         md4_transform_helper(mctx);
 183         data += avail;
 184         len -= avail;
 185
 186         while (len >= sizeof(mctx->block)) {
 187                 memcpy(mctx->block, data, sizeof(mctx->block));
 188                 md4_transform_helper(mctx);
 189                 data += sizeof(mctx->block);
 190                 len -= sizeof(mctx->block);
 191         }
 192
 193         memcpy(mctx->block, data, len);
 194 }
 195
 196 static void md4_final(struct crypto_tfm *tfm, u8 *out)
 197 {
 198         struct md4_ctx *mctx = crypto_tfm_ctx(tfm);
 199         const unsigned int offset = mctx->byte_count & 0x3f;
 200         char *p = (char *)mctx->block + offset;
 201         int padding = 56 - (offset + 1);
 202
 203         *p++ = 0x80;
 204         if (padding < 0) {
 205                 memset(p, 0x00, padding + sizeof (u64));
 206                 md4_transform_helper(mctx);
 207                 p = (char *)mctx->block;
 208                 padding = 56;
 209         }
 210
 211         memset(p, 0, padding);
 212         mctx->block[14] = mctx->byte_count << 3;
 213         mctx->block[15] = mctx->byte_count >> 29;
 214         le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
 215                           sizeof(u64)) / sizeof(u32));
 216         md4_transform(mctx->hash, mctx->block);
 217         cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
 218         memcpy(out, mctx->hash, sizeof(mctx->hash));
 219         memset(mctx, 0, sizeof(*mctx));
 220 }
 221
 222 static struct crypto_alg alg = {
 223         .cra_name       =       "md4",
 224         .cra_flags      =       CRYPTO_ALG_TYPE_DIGEST,
 225         .cra_blocksize  =       MD4_HMAC_BLOCK_SIZE,
 226         .cra_ctxsize    =       sizeof(struct md4_ctx),
 227         .cra_module     =       THIS_MODULE,
 228         .cra_list       =       LIST_HEAD_INIT(alg.cra_list),
 229         .cra_u          =       { .digest = {
 230         .dia_digestsize =       MD4_DIGEST_SIZE,
 231         .dia_init       =       md4_init,
 232         .dia_update     =       md4_update,
 233         .dia_final      =       md4_final } }
 234 };
 235
 236 static int __init md4_mod_init(void)
 237 {
 238         return crypto_register_alg(&alg);
 239 }
 240
 241 static void __exit md4_mod_fini(void)
 242 {
 243         crypto_unregister_alg(&alg);
 244 }
 245
 246 module_init(md4_mod_init);
 247 module_exit(md4_mod_fini);
 248
 249 MODULE_LICENSE("GPL");
 250 MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
 251