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/cpumask.h>
  18 #include <linux/err.h>
  19 #include <linux/init.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/rtnetlink.h>
  23 #include <linux/sched.h>
  24 #include <linux/slab.h>
  25 #include <linux/seq_file.h>
  26
  27 #include "internal.h"
  28
  29 static const char *skcipher_default_geniv __read_mostly;
  30
  31 static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
  32                             unsigned int keylen)
  33 {
  34         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
  35         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
  36         int ret;
  37         u8 *buffer, *alignbuffer;
  38         unsigned long absize;
  39
  40         absize = keylen + alignmask;
  41         buffer = kmalloc(absize, GFP_ATOMIC);
  42         if (!buffer)
  43                 return -ENOMEM;
  44
  45         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  46         memcpy(alignbuffer, key, keylen);
  47         ret = cipher->setkey(tfm, alignbuffer, keylen);
  48         memset(alignbuffer, 0, keylen);
  49         kfree(buffer);
  50         return ret;
  51 }
  52
  53 static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
  54                   unsigned int keylen)
  55 {
  56         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
  57         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
  58
  59         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
  60                 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
  61                 return -EINVAL;
  62         }
  63
  64         if ((unsigned long)key & alignmask)
  65                 return setkey_unaligned(tfm, key, keylen);
  66
  67         return cipher->setkey(tfm, key, keylen);
  68 }
  69
  70 static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
  71                                               u32 mask)
  72 {
  73         return alg->cra_ctxsize;
  74 }
  75
  76 int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
  77 {
  78         return crypto_ablkcipher_encrypt(&req->creq);
  79 }
  80
  81 int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
  82 {
  83         return crypto_ablkcipher_decrypt(&req->creq);
  84 }
  85
  86 static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
  87                                       u32 mask)
  88 {
  89         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
  90         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
  91
  92         if (alg->ivsize > PAGE_SIZE / 8)
  93                 return -EINVAL;
  94
  95         crt->setkey = setkey;
  96         crt->encrypt = alg->encrypt;
  97         crt->decrypt = alg->decrypt;
  98         if (!alg->ivsize) {
  99                 crt->givencrypt = skcipher_null_givencrypt;
 100                 crt->givdecrypt = skcipher_null_givdecrypt;
 101         }
 102         crt->base = __crypto_ablkcipher_cast(tfm);
 103         crt->ivsize = alg->ivsize;
 104
 105         return 0;
 106 }
 107
 108 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 109         __attribute__ ((unused));
 110 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 111 {
 112         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 113
 114         seq_printf(m, "type         : ablkcipher\n");
 115         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 116                                              "yes" : "no");
 117         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 118         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 119         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 120         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 121         seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
 122 }
 123
 124 const struct crypto_type crypto_ablkcipher_type = {
 125         .ctxsize = crypto_ablkcipher_ctxsize,
 126         .init = crypto_init_ablkcipher_ops,
 127 #ifdef CONFIG_PROC_FS
 128         .show = crypto_ablkcipher_show,
 129 #endif
 130 };
 131 EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
 132
 133 static int no_givdecrypt(struct skcipher_givcrypt_request *req)
 134 {
 135         return -ENOSYS;
 136 }
 137
 138 static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
 139                                       u32 mask)
 140 {
 141         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 142         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 143
 144         if (alg->ivsize > PAGE_SIZE / 8)
 145                 return -EINVAL;
 146
 147         crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
 148                       alg->setkey : setkey;
 149         crt->encrypt = alg->encrypt;
 150         crt->decrypt = alg->decrypt;
 151         crt->givencrypt = alg->givencrypt;
 152         crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
 153         crt->base = __crypto_ablkcipher_cast(tfm);
 154         crt->ivsize = alg->ivsize;
 155
 156         return 0;
 157 }
 158
 159 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 160         __attribute__ ((unused));
 161 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 162 {
 163         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 164
 165         seq_printf(m, "type         : givcipher\n");
 166         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 167                                              "yes" : "no");
 168         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 169         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 170         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 171         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 172         seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
 173 }
 174
 175 const struct crypto_type crypto_givcipher_type = {
 176         .ctxsize = crypto_ablkcipher_ctxsize,
 177         .init = crypto_init_givcipher_ops,
 178 #ifdef CONFIG_PROC_FS
 179         .show = crypto_givcipher_show,
 180 #endif
 181 };
 182 EXPORT_SYMBOL_GPL(crypto_givcipher_type);
 183
 184 const char *crypto_default_geniv(const struct crypto_alg *alg)
 185 {
 186         if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 187              CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 188                                          alg->cra_ablkcipher.ivsize) !=
 189             alg->cra_blocksize)
 190                 return "chainiv";
 191
 192         return alg->cra_flags & CRYPTO_ALG_ASYNC ?
 193                "eseqiv" : skcipher_default_geniv;
 194 }
 195
 196 static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
 197 {
 198         struct rtattr *tb[3];
 199         struct {
 200                 struct rtattr attr;
 201                 struct crypto_attr_type data;
 202         } ptype;
 203         struct {
 204                 struct rtattr attr;
 205                 struct crypto_attr_alg data;
 206         } palg;
 207         struct crypto_template *tmpl;
 208         struct crypto_instance *inst;
 209         struct crypto_alg *larval;
 210         const char *geniv;
 211         int err;
 212
 213         larval = crypto_larval_lookup(alg->cra_driver_name,
 214                                       (type & ~CRYPTO_ALG_TYPE_MASK) |
 215                                       CRYPTO_ALG_TYPE_GIVCIPHER,
 216                                       mask | CRYPTO_ALG_TYPE_MASK);
 217         err = PTR_ERR(larval);
 218         if (IS_ERR(larval))
 219                 goto out;
 220
 221         err = -EAGAIN;
 222         if (!crypto_is_larval(larval))
 223                 goto drop_larval;
 224
 225         ptype.attr.rta_len = sizeof(ptype);
 226         ptype.attr.rta_type = CRYPTOA_TYPE;
 227         ptype.data.type = type | CRYPTO_ALG_GENIV;
 228         /* GENIV tells the template that we're making a default geniv. */
 229         ptype.data.mask = mask | CRYPTO_ALG_GENIV;
 230         tb[0] = &ptype.attr;
 231
 232         palg.attr.rta_len = sizeof(palg);
 233         palg.attr.rta_type = CRYPTOA_ALG;
 234         /* Must use the exact name to locate ourselves. */
 235         memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
 236         tb[1] = &palg.attr;
 237
 238         tb[2] = NULL;
 239
 240         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 241             CRYPTO_ALG_TYPE_BLKCIPHER)
 242                 geniv = alg->cra_blkcipher.geniv;
 243         else
 244                 geniv = alg->cra_ablkcipher.geniv;
 245
 246         if (!geniv)
 247                 geniv = crypto_default_geniv(alg);
 248
 249         tmpl = crypto_lookup_template(geniv);
 250         err = -ENOENT;
 251         if (!tmpl)
 252                 goto kill_larval;
 253
 254         inst = tmpl->alloc(tb);
 255         err = PTR_ERR(inst);
 256         if (IS_ERR(inst))
 257                 goto put_tmpl;
 258
 259         if ((err = crypto_register_instance(tmpl, inst))) {
 260                 tmpl->free(inst);
 261                 goto put_tmpl;
 262         }
 263
 264         /* Redo the lookup to use the instance we just registered. */
 265         err = -EAGAIN;
 266
 267 put_tmpl:
 268         crypto_tmpl_put(tmpl);
 269 kill_larval:
 270         crypto_larval_kill(larval);
 271 drop_larval:
 272         crypto_mod_put(larval);
 273 out:
 274         crypto_mod_put(alg);
 275         return err;
 276 }
 277
 278 static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
 279                                                  u32 mask)
 280 {
 281         struct crypto_alg *alg;
 282
 283         alg = crypto_alg_mod_lookup(name, type, mask);
 284         if (IS_ERR(alg))
 285                 return alg;
 286
 287         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 288             CRYPTO_ALG_TYPE_GIVCIPHER)
 289                 return alg;
 290
 291         if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 292               CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 293                                           alg->cra_ablkcipher.ivsize))
 294                 return alg;
 295
 296         crypto_mod_put(alg);
 297         alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
 298                                     mask & ~CRYPTO_ALG_TESTED);
 299         if (IS_ERR(alg))
 300                 return alg;
 301
 302         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 303             CRYPTO_ALG_TYPE_GIVCIPHER) {
 304                 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
 305                         crypto_mod_put(alg);
 306                         alg = ERR_PTR(-ENOENT);
 307                 }
 308                 return alg;
 309         }
 310
 311         BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 312                  CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 313                                              alg->cra_ablkcipher.ivsize));
 314
 315         return ERR_PTR(crypto_givcipher_default(alg, type, mask));
 316 }
 317
 318 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
 319                          u32 type, u32 mask)
 320 {
 321         struct crypto_alg *alg;
 322         int err;
 323
 324         type = crypto_skcipher_type(type);
 325         mask = crypto_skcipher_mask(mask);
 326
 327         alg = crypto_lookup_skcipher(name, type, mask);
 328         if (IS_ERR(alg))
 329                 return PTR_ERR(alg);
 330
 331         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 332         crypto_mod_put(alg);
 333         return err;
 334 }
 335 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 336
 337 struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
 338                                                   u32 type, u32 mask)
 339 {
 340         struct crypto_tfm *tfm;
 341         int err;
 342
 343         type = crypto_skcipher_type(type);
 344         mask = crypto_skcipher_mask(mask);
 345
 346         for (;;) {
 347                 struct crypto_alg *alg;
 348
 349                 alg = crypto_lookup_skcipher(alg_name, type, mask);
 350                 if (IS_ERR(alg)) {
 351                         err = PTR_ERR(alg);
 352                         goto err;
 353                 }
 354
 355                 tfm = __crypto_alloc_tfm(alg, type, mask);
 356                 if (!IS_ERR(tfm))
 357                         return __crypto_ablkcipher_cast(tfm);
 358
 359                 crypto_mod_put(alg);
 360                 err = PTR_ERR(tfm);
 361
 362 err:
 363                 if (err != -EAGAIN)
 364                         break;
 365                 if (signal_pending(current)) {
 366                         err = -EINTR;
 367                         break;
 368                 }
 369         }
 370
 371         return ERR_PTR(err);
 372 }
 373 EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
 374
 375 static int __init skcipher_module_init(void)
 376 {
 377         skcipher_default_geniv = num_possible_cpus() > 1 ?
 378                                  "eseqiv" : "chainiv";
 379         return 0;
 380 }
 381
 382 static void skcipher_module_exit(void)
 383 {
 384 }
 385
 386 module_init(skcipher_module_init);
 387 module_exit(skcipher_module_exit);