LXR linux/crypto/hash.c

   1/*
   2 * Cryptographic Hash operations.
   3 * 
   4 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms of the GNU General Public License as published by the Free
   8 * Software Foundation; either version 2 of the License, or (at your option) 
   9 * any later version.
  10 */
  11
  12#include <linux/errno.h>
  13#include <linux/kernel.h>
  14#include <linux/module.h>
  15#include <linux/slab.h>
  16#include <linux/seq_file.h>
  17
  18#include "internal.h"
  19
  20static unsigned int crypto_hash_ctxsize(struct crypto_alg *alg, u32 type,
  21                                        u32 mask)
  22{
  23        return alg->cra_ctxsize;
  24}
  25
  26static int hash_setkey_unaligned(struct crypto_hash *crt, const u8 *key,
  27                                 unsigned int keylen)
  28{
  29        struct crypto_tfm *tfm = crypto_hash_tfm(crt);
  30        struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
  31        unsigned long alignmask = crypto_hash_alignmask(crt);
  32        int ret;
  33        u8 *buffer, *alignbuffer;
  34        unsigned long absize;
  35
  36        absize = keylen + alignmask;
  37        buffer = kmalloc(absize, GFP_ATOMIC);
  38        if (!buffer)
  39                return -ENOMEM;
  40
  41        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  42        memcpy(alignbuffer, key, keylen);
  43        ret = alg->setkey(crt, alignbuffer, keylen);
  44        memset(alignbuffer, 0, keylen);
  45        kfree(buffer);
  46        return ret;
  47}
  48
  49static int hash_setkey(struct crypto_hash *crt, const u8 *key,
  50                       unsigned int keylen)
  51{
  52        struct crypto_tfm *tfm = crypto_hash_tfm(crt);
  53        struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
  54        unsigned long alignmask = crypto_hash_alignmask(crt);
  55
  56        if ((unsigned long)key & alignmask)
  57                return hash_setkey_unaligned(crt, key, keylen);
  58
  59        return alg->setkey(crt, key, keylen);
  60}
  61
  62static int crypto_init_hash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
  63{
  64        struct hash_tfm *crt = &tfm->crt_hash;
  65        struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
  66
  67        if (alg->digestsize > crypto_tfm_alg_blocksize(tfm))
  68                return -EINVAL;
  69
  70        crt->init = alg->init;
  71        crt->update = alg->update;
  72        crt->final = alg->final;
  73        crt->digest = alg->digest;
  74        crt->setkey = hash_setkey;
  75        crt->digestsize = alg->digestsize;
  76
  77        return 0;
  78}
  79
  80static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
  81        __attribute__ ((unused));
  82static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
  83{
  84        seq_printf(m, "type         : hash\n");
  85        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
  86        seq_printf(m, "digestsize   : %u\n", alg->cra_hash.digestsize);
  87}
  88
  89const struct crypto_type crypto_hash_type = {
  90        .ctxsize = crypto_hash_ctxsize,
  91        .init = crypto_init_hash_ops,
  92#ifdef CONFIG_PROC_FS
  93        .show = crypto_hash_show,
  94#endif
  95};
  96EXPORT_SYMBOL_GPL(crypto_hash_type);
  97
  98MODULE_LICENSE("GPL");
  99MODULE_DESCRIPTION("Generic cryptographic hash type");
 100