LXR linux-old/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
  21static void init(struct crypto_tfm *tfm)
  22{
  23        tfm->__crt_alg->cra_digest.dia_init(crypto_tfm_ctx(tfm));
  24}
  25
  26static 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
  33                struct page *pg = sg[i].page;
  34                unsigned int offset = sg[i].offset;
  35                unsigned int l = sg[i].length;
  36
  37                do {
  38                        unsigned int bytes_from_page = min(l, ((unsigned int)
  39                                                           (PAGE_SIZE)) - 
  40                                                           offset);
  41                        char *p = crypto_kmap(pg, 0) + offset;
  42
  43                        tfm->__crt_alg->cra_digest.dia_update
  44                                        (crypto_tfm_ctx(tfm), p,
  45                                         bytes_from_page);
  46                        crypto_kunmap(p, 0);
  47                        crypto_yield(tfm);
  48                        offset = 0;
  49                        pg++;
  50                        l -= bytes_from_page;
  51                } while (l > 0);
  52        }
  53}
  54
  55static void final(struct crypto_tfm *tfm, u8 *out)
  56{
  57        tfm->__crt_alg->cra_digest.dia_final(crypto_tfm_ctx(tfm), out);
  58}
  59
  60static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
  61{
  62        u32 flags;
  63        if (tfm->__crt_alg->cra_digest.dia_setkey == NULL)
  64                return -ENOSYS;
  65        return tfm->__crt_alg->cra_digest.dia_setkey(crypto_tfm_ctx(tfm),
  66                                                     key, keylen, &flags);
  67}
  68
  69static void digest(struct crypto_tfm *tfm,
  70                   struct scatterlist *sg, unsigned int nsg, u8 *out)
  71{
  72        unsigned int i;
  73
  74        tfm->crt_digest.dit_init(tfm);
  75                
  76        for (i = 0; i < nsg; i++) {
  77                char *p = crypto_kmap(sg[i].page, 0) + sg[i].offset;
  78                tfm->__crt_alg->cra_digest.dia_update(crypto_tfm_ctx(tfm),
  79                                                      p, sg[i].length);
  80                crypto_kunmap(p, 0);
  81                crypto_yield(tfm);
  82        }
  83        crypto_digest_final(tfm, out);
  84}
  85
  86int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)
  87{
  88        return flags ? -EINVAL : 0;
  89}
  90
  91int crypto_init_digest_ops(struct crypto_tfm *tfm)
  92{
  93        struct digest_tfm *ops = &tfm->crt_digest;
  94        
  95        ops->dit_init   = init;
  96        ops->dit_update = update;
  97        ops->dit_final  = final;
  98        ops->dit_digest = digest;
  99        ops->dit_setkey = setkey;
 100        
 101        return crypto_alloc_hmac_block(tfm);
 102}
 103
 104void crypto_exit_digest_ops(struct crypto_tfm *tfm)
 105{
 106        crypto_free_hmac_block(tfm);
 107}
 108