release/src-rt-6.x/linux/linux-2.6/crypto/digest.c

   1 /*
   2  * Cryptographic API.
   3  *
   4  * Digest operations.
   5  *
   6  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  */
  14
  15 #include <linux/mm.h>
  16 #include <linux/errno.h>
  17 #include <linux/hardirq.h>
  18 #include <linux/highmem.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/scatterlist.h>
  22
  23 #include "internal.h"
  24 #include "scatterwalk.h"
  25
  26 void crypto_digest_init(struct crypto_tfm *tfm)
  27 {
  28         struct crypto_hash *hash = crypto_hash_cast(tfm);
  29         struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
  30
  31         crypto_hash_init(&desc);
  32 }
  33 EXPORT_SYMBOL_GPL(crypto_digest_init);
  34
  35 void crypto_digest_update(struct crypto_tfm *tfm,
  36                           struct scatterlist *sg, unsigned int nsg)
  37 {
  38         struct crypto_hash *hash = crypto_hash_cast(tfm);
  39         struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
  40         unsigned int nbytes = 0;
  41         unsigned int i;
  42
  43         for (i = 0; i < nsg; i++)
  44                 nbytes += sg[i].length;
  45
  46         crypto_hash_update(&desc, sg, nbytes);
  47 }
  48 EXPORT_SYMBOL_GPL(crypto_digest_update);
  49
  50 void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
  51 {
  52         struct crypto_hash *hash = crypto_hash_cast(tfm);
  53         struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
  54
  55         crypto_hash_final(&desc, out);
  56 }
  57 EXPORT_SYMBOL_GPL(crypto_digest_final);
  58
  59 void crypto_digest_digest(struct crypto_tfm *tfm,
  60                           struct scatterlist *sg, unsigned int nsg, u8 *out)
  61 {
  62         struct crypto_hash *hash = crypto_hash_cast(tfm);
  63         struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
  64         unsigned int nbytes = 0;
  65         unsigned int i;
  66
  67         for (i = 0; i < nsg; i++)
  68                 nbytes += sg[i].length;
  69
  70         crypto_hash_digest(&desc, sg, nbytes, out);
  71 }
  72 EXPORT_SYMBOL_GPL(crypto_digest_digest);
  73
  74 static int init(struct hash_desc *desc)
  75 {
  76         struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
  77
  78         tfm->__crt_alg->cra_digest.dia_init(tfm);
  79         return 0;
  80 }
  81
  82 static int update2(struct hash_desc *desc,
  83                    struct scatterlist *sg, unsigned int nbytes)
  84 {
  85         struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
  86         unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
  87
  88         if (!nbytes)
  89                 return 0;
  90
  91         for (;;) {
  92                 struct page *pg = sg->page;
  93                 unsigned int offset = sg->offset;
  94                 unsigned int l = sg->length;
  95
  96                 if (unlikely(l > nbytes))
  97                         l = nbytes;
  98                 nbytes -= l;
  99
 100                 do {
 101                         unsigned int bytes_from_page = min(l, ((unsigned int)
 102                                                            (PAGE_SIZE)) -
 103                                                            offset);
 104                         char *src = crypto_kmap(pg, 0);
 105                         char *p = src + offset;
 106
 107                         if (unlikely(offset & alignmask)) {
 108                                 unsigned int bytes =
 109                                         alignmask + 1 - (offset & alignmask);
 110                                 bytes = min(bytes, bytes_from_page);
 111                                 tfm->__crt_alg->cra_digest.dia_update(tfm, p,
 112                                                                       bytes);
 113                                 p += bytes;
 114                                 bytes_from_page -= bytes;
 115                                 l -= bytes;
 116                         }
 117                         tfm->__crt_alg->cra_digest.dia_update(tfm, p,
 118                                                               bytes_from_page);
 119                         crypto_kunmap(src, 0);
 120                         crypto_yield(desc->flags);
 121                         offset = 0;
 122                         pg++;
 123                         l -= bytes_from_page;
 124                 } while (l > 0);
 125
 126                 if (!nbytes)
 127                         break;
 128                 sg = scatterwalk_sg_next(sg);
 129         }
 130
 131         return 0;
 132 }
 133
 134 static int update(struct hash_desc *desc,
 135                   struct scatterlist *sg, unsigned int nbytes)
 136 {
 137         if (WARN_ON_ONCE(in_irq()))
 138                 return -EDEADLK;
 139         return update2(desc, sg, nbytes);
 140 }
 141
 142 static int final(struct hash_desc *desc, u8 *out)
 143 {
 144         struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
 145         unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 146         struct digest_alg *digest = &tfm->__crt_alg->cra_digest;
 147
 148         if (unlikely((unsigned long)out & alignmask)) {
 149                 unsigned long align = alignmask + 1;
 150                 unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
 151                 u8 *dst = (u8 *)ALIGN(addr, align) +
 152                           ALIGN(tfm->__crt_alg->cra_ctxsize, align);
 153
 154                 digest->dia_final(tfm, dst);
 155                 memcpy(out, dst, digest->dia_digestsize);
 156         } else
 157                 digest->dia_final(tfm, out);
 158
 159         return 0;
 160 }
 161
 162 static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen)
 163 {
 164         crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
 165         return -ENOSYS;
 166 }
 167
 168 static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen)
 169 {
 170         struct crypto_tfm *tfm = crypto_hash_tfm(hash);
 171
 172         crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK);
 173         return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
 174 }
 175
 176 static int digest(struct hash_desc *desc,
 177                   struct scatterlist *sg, unsigned int nbytes, u8 *out)
 178 {
 179         if (WARN_ON_ONCE(in_irq()))
 180                 return -EDEADLK;
 181
 182         init(desc);
 183         update2(desc, sg, nbytes);
 184         return final(desc, out);
 185 }
 186
 187 int crypto_init_digest_ops(struct crypto_tfm *tfm)
 188 {
 189         struct hash_tfm *ops = &tfm->crt_hash;
 190         struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;
 191
 192         if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm))
 193                 return -EINVAL;
 194
 195         ops->init       = init;
 196         ops->update     = update;
 197         ops->final      = final;
 198         ops->digest     = digest;
 199         ops->setkey     = dalg->dia_setkey ? setkey : nosetkey;
 200         ops->digestsize = dalg->dia_digestsize;
 201
 202         return 0;
 203 }
 204
 205 void crypto_exit_digest_ops(struct crypto_tfm *tfm)
 206 {
 207 }