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 <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
  21 static unsigned int crypto_hash_ctxsize(struct crypto_alg *alg, u32 type,
  22                                         u32 mask)
  23 {
  24         return alg->cra_ctxsize;
  25 }
  26
  27 static 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
  50 static 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
  63 static 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
  73 static 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
  85 static 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
  97 static 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
 109 static 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
 121 static 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
 136 static 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
 151 static 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
 164 static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
 165         __attribute__ ((unused));
 166 static 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
 173 const 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 };
 180 EXPORT_SYMBOL_GPL(crypto_hash_type);
 181
 182 MODULE_LICENSE("GPL");
 183 MODULE_DESCRIPTION("Generic cryptographic hash type");