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 <crypto/scatterwalk.h>
  16 #include <linux/mm.h>
  17 #include <linux/errno.h>
  18 #include <linux/hardirq.h>
  19 #include <linux/highmem.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/scatterlist.h>
  23
  24 <<<<<<< HEAD:crypto/digest.c
  25 =======
  26 #include "internal.h"
  27
  28 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:crypto/digest.c
  29 static int init(struct hash_desc *desc)
  30 {
  31         struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
  32
  33         tfm->__crt_alg->cra_digest.dia_init(tfm);
  34         return 0;
  35 }
  36
  37 static int update2(struct hash_desc *desc,
  38                    struct scatterlist *sg, unsigned int nbytes)
  39 {
  40         struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
  41         unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
  42
  43         if (!nbytes)
  44                 return 0;
  45
  46         for (;;) {
  47                 struct page *pg = sg_page(sg);
  48                 unsigned int offset = sg->offset;
  49                 unsigned int l = sg->length;
  50
  51                 if (unlikely(l > nbytes))
  52                         l = nbytes;
  53                 nbytes -= l;
  54
  55                 do {
  56                         unsigned int bytes_from_page = min(l, ((unsigned int)
  57                                                            (PAGE_SIZE)) -
  58                                                            offset);
  59                         char *src = crypto_kmap(pg, 0);
  60                         char *p = src + offset;
  61
  62                         if (unlikely(offset & alignmask)) {
  63                                 unsigned int bytes =
  64                                         alignmask + 1 - (offset & alignmask);
  65                                 bytes = min(bytes, bytes_from_page);
  66                                 tfm->__crt_alg->cra_digest.dia_update(tfm, p,
  67                                                                       bytes);
  68                                 p += bytes;
  69                                 bytes_from_page -= bytes;
  70                                 l -= bytes;
  71                         }
  72                         tfm->__crt_alg->cra_digest.dia_update(tfm, p,
  73                                                               bytes_from_page);
  74                         crypto_kunmap(src, 0);
  75                         crypto_yield(desc->flags);
  76                         offset = 0;
  77                         pg++;
  78                         l -= bytes_from_page;
  79                 } while (l > 0);
  80
  81                 if (!nbytes)
  82                         break;
  83                 sg = scatterwalk_sg_next(sg);
  84         }
  85
  86         return 0;
  87 }
  88
  89 static int update(struct hash_desc *desc,
  90                   struct scatterlist *sg, unsigned int nbytes)
  91 {
  92         if (WARN_ON_ONCE(in_irq()))
  93                 return -EDEADLK;
  94         return update2(desc, sg, nbytes);
  95 }
  96
  97 static int final(struct hash_desc *desc, u8 *out)
  98 {
  99         struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
 100         unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 101         struct digest_alg *digest = &tfm->__crt_alg->cra_digest;
 102
 103         if (unlikely((unsigned long)out & alignmask)) {
 104                 unsigned long align = alignmask + 1;
 105                 unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
 106                 u8 *dst = (u8 *)ALIGN(addr, align) +
 107                           ALIGN(tfm->__crt_alg->cra_ctxsize, align);
 108
 109                 digest->dia_final(tfm, dst);
 110                 memcpy(out, dst, digest->dia_digestsize);
 111         } else
 112                 digest->dia_final(tfm, out);
 113
 114         return 0;
 115 }
 116
 117 static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen)
 118 {
 119         crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
 120         return -ENOSYS;
 121 }
 122
 123 static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen)
 124 {
 125         struct crypto_tfm *tfm = crypto_hash_tfm(hash);
 126
 127         crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK);
 128         return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
 129 }
 130
 131 static int digest(struct hash_desc *desc,
 132                   struct scatterlist *sg, unsigned int nbytes, u8 *out)
 133 {
 134         if (WARN_ON_ONCE(in_irq()))
 135                 return -EDEADLK;
 136
 137         init(desc);
 138         update2(desc, sg, nbytes);
 139         return final(desc, out);
 140 }
 141
 142 int crypto_init_digest_ops(struct crypto_tfm *tfm)
 143 {
 144         struct hash_tfm *ops = &tfm->crt_hash;
 145         struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;
 146
 147         if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm))
 148                 return -EINVAL;
 149
 150         ops->init       = init;
 151         ops->update     = update;
 152         ops->final      = final;
 153         ops->digest     = digest;
 154         ops->setkey     = dalg->dia_setkey ? setkey : nosetkey;
 155         ops->digestsize = dalg->dia_digestsize;
 156
 157         return 0;
 158 }
 159
 160 void crypto_exit_digest_ops(struct crypto_tfm *tfm)
 161 {
 162 }