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 #include <linux/crypto.h>
  15 #include <linux/mm.h>
  16 #include <linux/errno.h>
  17 #include <linux/highmem.h>
  18 #include <asm/scatterlist.h>
  19 #include "internal.h"
  20
  21 static void init(struct crypto_tfm *tfm)
  22 {
  23         tfm->__crt_alg->cra_digest.dia_init(crypto_tfm_ctx(tfm));
  24 }
  25
  26 static void update(struct crypto_tfm *tfm,
  27                    struct scatterlist *sg, unsigned int nsg)
  28 {
  29         unsigned int i;
  30
  31         for (i = 0; i < nsg; i++) {
  32                 char *p = crypto_kmap(sg[i].page, 0) + sg[i].offset;
  33                 tfm->__crt_alg->cra_digest.dia_update(crypto_tfm_ctx(tfm),
  34                                                       p, sg[i].length);
  35                 crypto_kunmap(p, 0);
  36                 crypto_yield(tfm);
  37         }
  38 }
  39
  40 static void final(struct crypto_tfm *tfm, u8 *out)
  41 {
  42         tfm->__crt_alg->cra_digest.dia_final(crypto_tfm_ctx(tfm), out);
  43 }
  44
  45 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
  46 {
  47         u32 flags;
  48         if (tfm->__crt_alg->cra_digest.dia_setkey == NULL)
  49                 return -ENOSYS;
  50         return tfm->__crt_alg->cra_digest.dia_setkey(crypto_tfm_ctx(tfm),
  51                                                      key, keylen, &flags);
  52 }
  53
  54 static void digest(struct crypto_tfm *tfm,
  55                    struct scatterlist *sg, unsigned int nsg, u8 *out)
  56 {
  57         unsigned int i;
  58
  59         tfm->crt_digest.dit_init(tfm);
  60
  61         for (i = 0; i < nsg; i++) {
  62                 char *p = crypto_kmap(sg[i].page, 0) + sg[i].offset;
  63                 tfm->__crt_alg->cra_digest.dia_update(crypto_tfm_ctx(tfm),
  64                                                       p, sg[i].length);
  65                 crypto_kunmap(p, 0);
  66                 crypto_yield(tfm);
  67         }
  68         crypto_digest_final(tfm, out);
  69 }
  70
  71 int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)
  72 {
  73         return flags ? -EINVAL : 0;
  74 }
  75
  76 int crypto_init_digest_ops(struct crypto_tfm *tfm)
  77 {
  78         struct digest_tfm *ops = &tfm->crt_digest;
  79
  80         ops->dit_init   = init;
  81         ops->dit_update = update;
  82         ops->dit_final  = final;
  83         ops->dit_digest = digest;
  84         ops->dit_setkey = setkey;
  85
  86         return crypto_alloc_hmac_block(tfm);
  87 }
  88
  89 void crypto_exit_digest_ops(struct crypto_tfm *tfm)
  90 {
  91         crypto_free_hmac_block(tfm);
  92 }