crypto/ablkcipher.c

   1 /*
   2  * Asynchronous block chaining cipher operations.
   3  *
   4  * This is the asynchronous version of blkcipher.c indicating completion
   5  * via a callback.
   6  *
   7  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the Free
  11  * Software Foundation; either version 2 of the License, or (at your option)
  12  * any later version.
  13  *
  14  */
  15
  16 #include <crypto/algapi.h>
  17 #include <linux/errno.h>
  18 #include <linux/init.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/slab.h>
  22 #include <linux/seq_file.h>
  23
  24 static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
  25                             unsigned int keylen)
  26 {
  27         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
  28         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
  29         int ret;
  30         u8 *buffer, *alignbuffer;
  31         unsigned long absize;
  32
  33         absize = keylen + alignmask;
  34         buffer = kmalloc(absize, GFP_ATOMIC);
  35         if (!buffer)
  36                 return -ENOMEM;
  37
  38         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  39         memcpy(alignbuffer, key, keylen);
  40         ret = cipher->setkey(tfm, alignbuffer, keylen);
  41         memset(alignbuffer, 0, keylen);
  42         kfree(buffer);
  43         return ret;
  44 }
  45
  46 static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
  47                   unsigned int keylen)
  48 {
  49         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
  50         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
  51
  52         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
  53                 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
  54                 return -EINVAL;
  55         }
  56
  57         if ((unsigned long)key & alignmask)
  58                 return setkey_unaligned(tfm, key, keylen);
  59
  60         return cipher->setkey(tfm, key, keylen);
  61 }
  62
  63 static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
  64                                               u32 mask)
  65 {
  66         return alg->cra_ctxsize;
  67 }
  68
  69 static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
  70                                       u32 mask)
  71 {
  72         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
  73         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
  74
  75         if (alg->ivsize > PAGE_SIZE / 8)
  76                 return -EINVAL;
  77
  78         crt->setkey = setkey;
  79         crt->encrypt = alg->encrypt;
  80         crt->decrypt = alg->decrypt;
  81         crt->ivsize = alg->ivsize;
  82
  83         return 0;
  84 }
  85
  86 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
  87         __attribute__ ((unused));
  88 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
  89 {
  90         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
  91
  92         seq_printf(m, "type         : ablkcipher\n");
  93         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
  94         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
  95         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
  96         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
  97 }
  98
  99 const struct crypto_type crypto_ablkcipher_type = {
 100         .ctxsize = crypto_ablkcipher_ctxsize,
 101         .init = crypto_init_ablkcipher_ops,
 102 #ifdef CONFIG_PROC_FS
 103         .show = crypto_ablkcipher_show,
 104 #endif
 105 };
 106 EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
 107
 108 MODULE_LICENSE("GPL");
 109 MODULE_DESCRIPTION("Asynchronous block chaining cipher type");