linux/crypto/hash.c
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   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 <crypto/internal/hash.h>
  13#include <linux/errno.h>
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/slab.h>
  17#include <linux/seq_file.h>
  18
  19#include "internal.h"
  20
  21static unsigned int crypto_hash_ctxsize(struct crypto_alg *alg, u32 type,
  22                                        u32 mask)
  23{
  24        return alg->cra_ctxsize;
  25}
  26
  27static int hash_setkey_unaligned(struct crypto_hash *crt, const u8 *key,
  28                                 unsigned int keylen)
  29{
  30        struct crypto_tfm *tfm = crypto_hash_tfm(crt);
  31        struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
  32        unsigned long alignmask = crypto_hash_alignmask(crt);
  33        int ret;
  34        u8 *buffer, *alignbuffer;
  35        unsigned long absize;
  36
  37        absize = keylen + alignmask;
  38        buffer = kmalloc(absize, GFP_ATOMIC);
  39        if (!buffer)
  40                return -ENOMEM;
  41
  42        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  43        memcpy(alignbuffer, key, keylen);
  44        ret = alg->setkey(crt, alignbuffer, keylen);
  45        memset(alignbuffer, 0, keylen);
  46        kfree(buffer);
  47        return ret;
  48}
  49
  50static int hash_setkey(struct crypto_hash *crt, const u8 *key,
  51                       unsigned int keylen)
  52{
  53        struct crypto_tfm *tfm = crypto_hash_tfm(crt);
  54        struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
  55        unsigned long alignmask = crypto_hash_alignmask(crt);
  56
  57        if ((unsigned long)key & alignmask)
  58                return hash_setkey_unaligned(crt, key, keylen);
  59
  60        return alg->setkey(crt, key, keylen);
  61}
  62
  63static int hash_async_setkey(struct crypto_ahash *tfm_async, const u8 *key,
  64                        unsigned int keylen)
  65{
  66        struct crypto_tfm  *tfm      = crypto_ahash_tfm(tfm_async);
  67        struct crypto_hash *tfm_hash = __crypto_hash_cast(tfm);
  68        struct hash_alg    *alg      = &tfm->__crt_alg->cra_hash;
  69
  70        return alg->setkey(tfm_hash, key, keylen);
  71}
  72
  73static int hash_async_init(struct ahash_request *req)
  74{
  75        struct crypto_tfm *tfm = req->base.tfm;
  76        struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
  77        struct hash_desc  desc = {
  78                .tfm = __crypto_hash_cast(tfm),
  79                .flags = req->base.flags,
  80        };
  81
  82        return alg->init(&desc);
  83}
  84
  85static int hash_async_update(struct ahash_request *req)
  86{
  87        struct crypto_tfm *tfm = req->base.tfm;
  88        struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
  89        struct hash_desc  desc = {
  90                .tfm = __crypto_hash_cast(tfm),
  91                .flags = req->base.flags,
  92        };
  93
  94        return alg->update(&desc, req->src, req->nbytes);
  95}
  96
  97static int hash_async_final(struct ahash_request *req)
  98{
  99        struct crypto_tfm *tfm = req->base.tfm;
 100        struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
 101        struct hash_desc  desc = {
 102                .tfm = __crypto_hash_cast(tfm),
 103                .flags = req->base.flags,
 104        };
 105
 106        return alg->final(&desc, req->result);
 107}
 108
 109static int hash_async_digest(struct ahash_request *req)
 110{
 111        struct crypto_tfm *tfm = req->base.tfm;
 112        struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
 113        struct hash_desc  desc = {
 114                .tfm = __crypto_hash_cast(tfm),
 115                .flags = req->base.flags,
 116        };
 117
 118        return alg->digest(&desc, req->src, req->nbytes, req->result);
 119}
 120
 121static int crypto_init_hash_ops_async(struct crypto_tfm *tfm)
 122{
 123        struct ahash_tfm *crt = &tfm->crt_ahash;
 124        struct hash_alg  *alg = &tfm->__crt_alg->cra_hash;
 125
 126        crt->init       = hash_async_init;
 127        crt->update     = hash_async_update;
 128        crt->final      = hash_async_final;
 129        crt->digest     = hash_async_digest;
 130        crt->setkey     = hash_async_setkey;
 131        crt->digestsize = alg->digestsize;
 132
 133        return 0;
 134}
 135
 136static int crypto_init_hash_ops_sync(struct crypto_tfm *tfm)
 137{
 138        struct hash_tfm *crt = &tfm->crt_hash;
 139        struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
 140
 141        crt->init       = alg->init;
 142        crt->update     = alg->update;
 143        crt->final      = alg->final;
 144        crt->digest     = alg->digest;
 145        crt->setkey     = hash_setkey;
 146        crt->digestsize = alg->digestsize;
 147
 148        return 0;
 149}
 150
 151static int crypto_init_hash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 152{
 153        struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
 154
 155        if (alg->digestsize > PAGE_SIZE / 8)
 156                return -EINVAL;
 157
 158        if ((mask & CRYPTO_ALG_TYPE_HASH_MASK) != CRYPTO_ALG_TYPE_HASH_MASK)
 159                return crypto_init_hash_ops_async(tfm);
 160        else
 161                return crypto_init_hash_ops_sync(tfm);
 162}
 163
 164static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
 165        __attribute__ ((unused));
 166static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
 167{
 168        seq_printf(m, "type         : hash\n");
 169        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 170        seq_printf(m, "digestsize   : %u\n", alg->cra_hash.digestsize);
 171}
 172
 173const struct crypto_type crypto_hash_type = {
 174        .ctxsize = crypto_hash_ctxsize,
 175        .init = crypto_init_hash_ops,
 176#ifdef CONFIG_PROC_FS
 177        .show = crypto_hash_show,
 178#endif
 179};
 180EXPORT_SYMBOL_GPL(crypto_hash_type);
 181
 182MODULE_LICENSE("GPL");
 183MODULE_DESCRIPTION("Generic cryptographic hash type");
 184