LXR linux/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
  24static 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
  46static 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
  63static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
  64                                              u32 mask)
  65{
  66        return alg->cra_ctxsize;
  67}
  68
  69static 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
  86static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
  87        __attribute__ ((unused));
  88static 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
  99const 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};
 106EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
 107
 108MODULE_LICENSE("GPL");
 109MODULE_DESCRIPTION("Asynchronous block chaining cipher type");
 110