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
  20 static unsigned int crypto_hash_ctxsize(struct crypto_alg *alg, u32 type,
  21                                         u32 mask)
  22 {
  23         return alg->cra_ctxsize;
  24 }
  25
  26 static 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
  49 static 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
  62 static int hash_async_setkey(struct crypto_ahash *tfm_async, const u8 *key,
  63                         unsigned int keylen)
  64 {
  65         struct crypto_tfm  *tfm      = crypto_ahash_tfm(tfm_async);
  66         struct crypto_hash *tfm_hash = __crypto_hash_cast(tfm);
  67         struct hash_alg    *alg      = &tfm->__crt_alg->cra_hash;
  68
  69         return alg->setkey(tfm_hash, key, keylen);
  70 }
  71
  72 static int hash_async_init(struct ahash_request *req)
  73 {
  74         struct crypto_tfm *tfm = req->base.tfm;
  75         struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
  76         struct hash_desc  desc = {
  77                 .tfm = __crypto_hash_cast(tfm),
  78                 .flags = req->base.flags,
  79         };
  80
  81         return alg->init(&desc);
  82 }
  83
  84 static int hash_async_update(struct ahash_request *req)
  85 {
  86         struct crypto_tfm *tfm = req->base.tfm;
  87         struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
  88         struct hash_desc  desc = {
  89                 .tfm = __crypto_hash_cast(tfm),
  90                 .flags = req->base.flags,
  91         };
  92
  93         return alg->update(&desc, req->src, req->nbytes);
  94 }
  95
  96 static int hash_async_final(struct ahash_request *req)
  97 {
  98         struct crypto_tfm *tfm = req->base.tfm;
  99         struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
 100         struct hash_desc  desc = {
 101                 .tfm = __crypto_hash_cast(tfm),
 102                 .flags = req->base.flags,
 103         };
 104
 105         return alg->final(&desc, req->result);
 106 }
 107
 108 static int hash_async_digest(struct ahash_request *req)
 109 {
 110         struct crypto_tfm *tfm = req->base.tfm;
 111         struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
 112         struct hash_desc  desc = {
 113                 .tfm = __crypto_hash_cast(tfm),
 114                 .flags = req->base.flags,
 115         };
 116
 117         return alg->digest(&desc, req->src, req->nbytes, req->result);
 118 }
 119
 120 static int crypto_init_hash_ops_async(struct crypto_tfm *tfm)
 121 {
 122         struct ahash_tfm *crt = &tfm->crt_ahash;
 123         struct hash_alg  *alg = &tfm->__crt_alg->cra_hash;
 124
 125         crt->init       = hash_async_init;
 126         crt->update     = hash_async_update;
 127         crt->final      = hash_async_final;
 128         crt->digest     = hash_async_digest;
 129         crt->setkey     = hash_async_setkey;
 130         crt->digestsize = alg->digestsize;
 131
 132         return 0;
 133 }
 134
 135 static int crypto_init_hash_ops_sync(struct crypto_tfm *tfm)
 136 {
 137         struct hash_tfm *crt = &tfm->crt_hash;
 138         struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
 139
 140         crt->init       = alg->init;
 141         crt->update     = alg->update;
 142         crt->final      = alg->final;
 143         crt->digest     = alg->digest;
 144         crt->setkey     = hash_setkey;
 145         crt->digestsize = alg->digestsize;
 146
 147         return 0;
 148 }
 149
 150 static int crypto_init_hash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 151 {
 152         struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
 153
 154         if (alg->digestsize > PAGE_SIZE / 8)
 155                 return -EINVAL;
 156
 157         if ((mask & CRYPTO_ALG_TYPE_HASH_MASK) != CRYPTO_ALG_TYPE_HASH_MASK)
 158                 return crypto_init_hash_ops_async(tfm);
 159         else
 160                 return crypto_init_hash_ops_sync(tfm);
 161 }
 162
 163 static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
 164         __attribute__ ((unused));
 165 static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
 166 {
 167         seq_printf(m, "type         : hash\n");
 168         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 169         seq_printf(m, "digestsize   : %u\n", alg->cra_hash.digestsize);
 170 }
 171
 172 const struct crypto_type crypto_hash_type = {
 173         .ctxsize = crypto_hash_ctxsize,
 174         .init = crypto_init_hash_ops,
 175 #ifdef CONFIG_PROC_FS
 176         .show = crypto_hash_show,
 177 #endif
 178 };
 179 EXPORT_SYMBOL_GPL(crypto_hash_type);
 180
 181 MODULE_LICENSE("GPL");
 182 MODULE_DESCRIPTION("Generic cryptographic hash type");