fs/smb/common/cifs_md4.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Cryptographic API.
   4  *
   5  * MD4 Message Digest Algorithm (RFC1320).
   6  *
   7  * Implementation derived from Andrew Tridgell and Steve French's
   8  * CIFS MD4 implementation, and the cryptoapi implementation
   9  * originally based on the public domain implementation written
  10  * by Colin Plumb in 1993.
  11  *
  12  * Copyright (c) Andrew Tridgell 1997-1998.
  13  * Modified by Steve French (sfrench@us.ibm.com) 2002
  14  * Copyright (c) Cryptoapi developers.
  15  * Copyright (c) 2002 David S. Miller (davem@redhat.com)
  16  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  17  *
  18  */
  19 #include <linux/init.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/string.h>
  23 #include <linux/types.h>
  24 #include <asm/byteorder.h>
  25 #include "md4.h"
  26
  27 MODULE_DESCRIPTION("MD4 Message Digest Algorithm (RFC1320)");
  28 MODULE_LICENSE("GPL");
  29
  30 static inline u32 lshift(u32 x, unsigned int s)
  31 {
  32         x &= 0xFFFFFFFF;
  33         return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
  34 }
  35
  36 static inline u32 F(u32 x, u32 y, u32 z)
  37 {
  38         return (x & y) | ((~x) & z);
  39 }
  40
  41 static inline u32 G(u32 x, u32 y, u32 z)
  42 {
  43         return (x & y) | (x & z) | (y & z);
  44 }
  45
  46 static inline u32 H(u32 x, u32 y, u32 z)
  47 {
  48         return x ^ y ^ z;
  49 }
  50
  51 #define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
  52 #define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (u32)0x5A827999,s))
  53 #define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (u32)0x6ED9EBA1,s))
  54
  55 static void md4_transform(u32 *hash, u32 const *in)
  56 {
  57         u32 a, b, c, d;
  58
  59         a = hash[0];
  60         b = hash[1];
  61         c = hash[2];
  62         d = hash[3];
  63
  64         ROUND1(a, b, c, d, in[0], 3);
  65         ROUND1(d, a, b, c, in[1], 7);
  66         ROUND1(c, d, a, b, in[2], 11);
  67         ROUND1(b, c, d, a, in[3], 19);
  68         ROUND1(a, b, c, d, in[4], 3);
  69         ROUND1(d, a, b, c, in[5], 7);
  70         ROUND1(c, d, a, b, in[6], 11);
  71         ROUND1(b, c, d, a, in[7], 19);
  72         ROUND1(a, b, c, d, in[8], 3);
  73         ROUND1(d, a, b, c, in[9], 7);
  74         ROUND1(c, d, a, b, in[10], 11);
  75         ROUND1(b, c, d, a, in[11], 19);
  76         ROUND1(a, b, c, d, in[12], 3);
  77         ROUND1(d, a, b, c, in[13], 7);
  78         ROUND1(c, d, a, b, in[14], 11);
  79         ROUND1(b, c, d, a, in[15], 19);
  80
  81         ROUND2(a, b, c, d, in[0], 3);
  82         ROUND2(d, a, b, c, in[4], 5);
  83         ROUND2(c, d, a, b, in[8], 9);
  84         ROUND2(b, c, d, a, in[12], 13);
  85         ROUND2(a, b, c, d, in[1], 3);
  86         ROUND2(d, a, b, c, in[5], 5);
  87         ROUND2(c, d, a, b, in[9], 9);
  88         ROUND2(b, c, d, a, in[13], 13);
  89         ROUND2(a, b, c, d, in[2], 3);
  90         ROUND2(d, a, b, c, in[6], 5);
  91         ROUND2(c, d, a, b, in[10], 9);
  92         ROUND2(b, c, d, a, in[14], 13);
  93         ROUND2(a, b, c, d, in[3], 3);
  94         ROUND2(d, a, b, c, in[7], 5);
  95         ROUND2(c, d, a, b, in[11], 9);
  96         ROUND2(b, c, d, a, in[15], 13);
  97
  98         ROUND3(a, b, c, d, in[0], 3);
  99         ROUND3(d, a, b, c, in[8], 9);
 100         ROUND3(c, d, a, b, in[4], 11);
 101         ROUND3(b, c, d, a, in[12], 15);
 102         ROUND3(a, b, c, d, in[2], 3);
 103         ROUND3(d, a, b, c, in[10], 9);
 104         ROUND3(c, d, a, b, in[6], 11);
 105         ROUND3(b, c, d, a, in[14], 15);
 106         ROUND3(a, b, c, d, in[1], 3);
 107         ROUND3(d, a, b, c, in[9], 9);
 108         ROUND3(c, d, a, b, in[5], 11);
 109         ROUND3(b, c, d, a, in[13], 15);
 110         ROUND3(a, b, c, d, in[3], 3);
 111         ROUND3(d, a, b, c, in[11], 9);
 112         ROUND3(c, d, a, b, in[7], 11);
 113         ROUND3(b, c, d, a, in[15], 15);
 114
 115         hash[0] += a;
 116         hash[1] += b;
 117         hash[2] += c;
 118         hash[3] += d;
 119 }
 120
 121 static inline void md4_transform_helper(struct md4_ctx *ctx)
 122 {
 123         le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
 124         md4_transform(ctx->hash, ctx->block);
 125 }
 126
 127 int cifs_md4_init(struct md4_ctx *mctx)
 128 {
 129         memset(mctx, 0, sizeof(struct md4_ctx));
 130         mctx->hash[0] = 0x67452301;
 131         mctx->hash[1] = 0xefcdab89;
 132         mctx->hash[2] = 0x98badcfe;
 133         mctx->hash[3] = 0x10325476;
 134         mctx->byte_count = 0;
 135
 136         return 0;
 137 }
 138 EXPORT_SYMBOL_GPL(cifs_md4_init);
 139
 140 int cifs_md4_update(struct md4_ctx *mctx, const u8 *data, unsigned int len)
 141 {
 142         const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
 143
 144         mctx->byte_count += len;
 145
 146         if (avail > len) {
 147                 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 148                        data, len);
 149                 return 0;
 150         }
 151
 152         memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
 153                data, avail);
 154
 155         md4_transform_helper(mctx);
 156         data += avail;
 157         len -= avail;
 158
 159         while (len >= sizeof(mctx->block)) {
 160                 memcpy(mctx->block, data, sizeof(mctx->block));
 161                 md4_transform_helper(mctx);
 162                 data += sizeof(mctx->block);
 163                 len -= sizeof(mctx->block);
 164         }
 165
 166         memcpy(mctx->block, data, len);
 167
 168         return 0;
 169 }
 170 EXPORT_SYMBOL_GPL(cifs_md4_update);
 171
 172 int cifs_md4_final(struct md4_ctx *mctx, u8 *out)
 173 {
 174         const unsigned int offset = mctx->byte_count & 0x3f;
 175         char *p = (char *)mctx->block + offset;
 176         int padding = 56 - (offset + 1);
 177
 178         *p++ = 0x80;
 179         if (padding < 0) {
 180                 memset(p, 0x00, padding + sizeof(u64));
 181                 md4_transform_helper(mctx);
 182                 p = (char *)mctx->block;
 183                 padding = 56;
 184         }
 185
 186         memset(p, 0, padding);
 187         mctx->block[14] = mctx->byte_count << 3;
 188         mctx->block[15] = mctx->byte_count >> 29;
 189         le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
 190                           sizeof(u64)) / sizeof(u32));
 191         md4_transform(mctx->hash, mctx->block);
 192         cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
 193         memcpy(out, mctx->hash, sizeof(mctx->hash));
 194         memset(mctx, 0, sizeof(*mctx));
 195
 196         return 0;
 197 }
 198 EXPORT_SYMBOL_GPL(cifs_md4_final);