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/internal/skcipher.h>
  17 #include <linux/err.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 #include "internal.h"
  25
  26 static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
  27                             unsigned int keylen)
  28 {
  29         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
  30         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
  31         int ret;
  32         u8 *buffer, *alignbuffer;
  33         unsigned long absize;
  34
  35         absize = keylen + alignmask;
  36         buffer = kmalloc(absize, GFP_ATOMIC);
  37         if (!buffer)
  38                 return -ENOMEM;
  39
  40         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  41         memcpy(alignbuffer, key, keylen);
  42         ret = cipher->setkey(tfm, alignbuffer, keylen);
  43         memset(alignbuffer, 0, keylen);
  44         kfree(buffer);
  45         return ret;
  46 }
  47
  48 static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
  49                   unsigned int keylen)
  50 {
  51         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
  52         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
  53
  54         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
  55                 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
  56                 return -EINVAL;
  57         }
  58
  59         if ((unsigned long)key & alignmask)
  60                 return setkey_unaligned(tfm, key, keylen);
  61
  62         return cipher->setkey(tfm, key, keylen);
  63 }
  64
  65 static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
  66                                               u32 mask)
  67 {
  68         return alg->cra_ctxsize;
  69 }
  70
  71 static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
  72                                       u32 mask)
  73 {
  74         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
  75         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
  76
  77         if (alg->ivsize > PAGE_SIZE / 8)
  78                 return -EINVAL;
  79
  80         crt->setkey = setkey;
  81         crt->encrypt = alg->encrypt;
  82         crt->decrypt = alg->decrypt;
  83         crt->ivsize = alg->ivsize;
  84
  85         return 0;
  86 }
  87
  88 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
  89         __attribute__ ((unused));
  90 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
  91 {
  92         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
  93
  94         seq_printf(m, "type         : ablkcipher\n");
  95         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
  96         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
  97         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
  98         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
  99 }
 100
 101 const struct crypto_type crypto_ablkcipher_type = {
 102         .ctxsize = crypto_ablkcipher_ctxsize,
 103         .init = crypto_init_ablkcipher_ops,
 104 #ifdef CONFIG_PROC_FS
 105         .show = crypto_ablkcipher_show,
 106 #endif
 107 };
 108 EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
 109
 110 static int no_givdecrypt(struct skcipher_givcrypt_request *req)
 111 {
 112         return -ENOSYS;
 113 }
 114
 115 static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
 116                                       u32 mask)
 117 {
 118         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 119         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 120
 121         if (alg->ivsize > PAGE_SIZE / 8)
 122                 return -EINVAL;
 123
 124         crt->setkey = setkey;
 125         crt->encrypt = alg->encrypt;
 126         crt->decrypt = alg->decrypt;
 127         crt->givencrypt = alg->givencrypt;
 128         crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
 129         crt->ivsize = alg->ivsize;
 130
 131         return 0;
 132 }
 133
 134 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 135         __attribute__ ((unused));
 136 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 137 {
 138         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 139
 140         seq_printf(m, "type         : givcipher\n");
 141         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 142         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 143         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 144         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 145 }
 146
 147 const struct crypto_type crypto_givcipher_type = {
 148         .ctxsize = crypto_ablkcipher_ctxsize,
 149         .init = crypto_init_givcipher_ops,
 150 #ifdef CONFIG_PROC_FS
 151         .show = crypto_givcipher_show,
 152 #endif
 153 };
 154 EXPORT_SYMBOL_GPL(crypto_givcipher_type);
 155
 156 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
 157                          u32 type, u32 mask)
 158 {
 159         struct crypto_alg *alg;
 160         int err;
 161
 162         type = crypto_skcipher_type(type);
 163         mask = crypto_skcipher_mask(mask);
 164
 165         alg = crypto_alg_mod_lookup(name, type, mask);
 166         if (IS_ERR(alg))
 167                 return PTR_ERR(alg);
 168
 169         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 170         crypto_mod_put(alg);
 171         return err;
 172 }
 173 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 174
 175 MODULE_LICENSE("GPL");
 176 MODULE_DESCRIPTION("Asynchronous block chaining cipher type");