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/kernel.h>
  19 #include <linux/slab.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/cryptouser.h>
  22 #include <linux/compiler.h>
  23 #include <net/netlink.h>
  24
  25 #include <crypto/scatterwalk.h>
  26
  27 #include "internal.h"
  28
  29 struct ablkcipher_buffer {
  30         struct list_head        entry;
  31         struct scatter_walk     dst;
  32         unsigned int            len;
  33         void                    *data;
  34 };
  35
  36 enum {
  37         ABLKCIPHER_WALK_SLOW = 1 << 0,
  38 };
  39
  40 static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
  41 {
  42         scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
  43 }
  44
  45 void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
  46 {
  47         struct ablkcipher_buffer *p, *tmp;
  48
  49         list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
  50                 ablkcipher_buffer_write(p);
  51                 list_del(&p->entry);
  52                 kfree(p);
  53         }
  54 }
  55 EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
  56
  57 static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
  58                                           struct ablkcipher_buffer *p)
  59 {
  60         p->dst = walk->out;
  61         list_add_tail(&p->entry, &walk->buffers);
  62 }
  63
  64 /* Get a spot of the specified length that does not straddle a page.
  65  * The caller needs to ensure that there is enough space for this operation.
  66  */
  67 static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
  68 {
  69         u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
  70
  71         return max(start, end_page);
  72 }
  73
  74 static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
  75                                                 unsigned int bsize)
  76 {
  77         unsigned int n = bsize;
  78
  79         for (;;) {
  80                 unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
  81
  82                 if (len_this_page > n)
  83                         len_this_page = n;
  84                 scatterwalk_advance(&walk->out, n);
  85                 if (n == len_this_page)
  86                         break;
  87                 n -= len_this_page;
  88                 scatterwalk_start(&walk->out, sg_next(walk->out.sg));
  89         }
  90
  91         return bsize;
  92 }
  93
  94 static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
  95                                                 unsigned int n)
  96 {
  97         scatterwalk_advance(&walk->in, n);
  98         scatterwalk_advance(&walk->out, n);
  99
 100         return n;
 101 }
 102
 103 static int ablkcipher_walk_next(struct ablkcipher_request *req,
 104                                 struct ablkcipher_walk *walk);
 105
 106 int ablkcipher_walk_done(struct ablkcipher_request *req,
 107                          struct ablkcipher_walk *walk, int err)
 108 {
 109         struct crypto_tfm *tfm = req->base.tfm;
 110         unsigned int nbytes = 0;
 111
 112         if (likely(err >= 0)) {
 113                 unsigned int n = walk->nbytes - err;
 114
 115                 if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
 116                         n = ablkcipher_done_fast(walk, n);
 117                 else if (WARN_ON(err)) {
 118                         err = -EINVAL;
 119                         goto err;
 120                 } else
 121                         n = ablkcipher_done_slow(walk, n);
 122
 123                 nbytes = walk->total - n;
 124                 err = 0;
 125         }
 126
 127         scatterwalk_done(&walk->in, 0, nbytes);
 128         scatterwalk_done(&walk->out, 1, nbytes);
 129
 130 err:
 131         walk->total = nbytes;
 132         walk->nbytes = nbytes;
 133
 134         if (nbytes) {
 135                 crypto_yield(req->base.flags);
 136                 return ablkcipher_walk_next(req, walk);
 137         }
 138
 139         if (walk->iv != req->info)
 140                 memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
 141         kfree(walk->iv_buffer);
 142
 143         return err;
 144 }
 145 EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
 146
 147 static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
 148                                        struct ablkcipher_walk *walk,
 149                                        unsigned int bsize,
 150                                        unsigned int alignmask,
 151                                        void **src_p, void **dst_p)
 152 {
 153         unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
 154         struct ablkcipher_buffer *p;
 155         void *src, *dst, *base;
 156         unsigned int n;
 157
 158         n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
 159         n += (aligned_bsize * 3 - (alignmask + 1) +
 160               (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
 161
 162         p = kmalloc(n, GFP_ATOMIC);
 163         if (!p)
 164                 return ablkcipher_walk_done(req, walk, -ENOMEM);
 165
 166         base = p + 1;
 167
 168         dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
 169         src = dst = ablkcipher_get_spot(dst, bsize);
 170
 171         p->len = bsize;
 172         p->data = dst;
 173
 174         scatterwalk_copychunks(src, &walk->in, bsize, 0);
 175
 176         ablkcipher_queue_write(walk, p);
 177
 178         walk->nbytes = bsize;
 179         walk->flags |= ABLKCIPHER_WALK_SLOW;
 180
 181         *src_p = src;
 182         *dst_p = dst;
 183
 184         return 0;
 185 }
 186
 187 static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
 188                                      struct crypto_tfm *tfm,
 189                                      unsigned int alignmask)
 190 {
 191         unsigned bs = walk->blocksize;
 192         unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
 193         unsigned aligned_bs = ALIGN(bs, alignmask + 1);
 194         unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
 195                             (alignmask + 1);
 196         u8 *iv;
 197
 198         size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
 199         walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
 200         if (!walk->iv_buffer)
 201                 return -ENOMEM;
 202
 203         iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
 204         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
 205         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
 206         iv = ablkcipher_get_spot(iv, ivsize);
 207
 208         walk->iv = memcpy(iv, walk->iv, ivsize);
 209         return 0;
 210 }
 211
 212 static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
 213                                        struct ablkcipher_walk *walk)
 214 {
 215         walk->src.page = scatterwalk_page(&walk->in);
 216         walk->src.offset = offset_in_page(walk->in.offset);
 217         walk->dst.page = scatterwalk_page(&walk->out);
 218         walk->dst.offset = offset_in_page(walk->out.offset);
 219
 220         return 0;
 221 }
 222
 223 static int ablkcipher_walk_next(struct ablkcipher_request *req,
 224                                 struct ablkcipher_walk *walk)
 225 {
 226         struct crypto_tfm *tfm = req->base.tfm;
 227         unsigned int alignmask, bsize, n;
 228         void *src, *dst;
 229         int err;
 230
 231         alignmask = crypto_tfm_alg_alignmask(tfm);
 232         n = walk->total;
 233         if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
 234                 req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
 235                 return ablkcipher_walk_done(req, walk, -EINVAL);
 236         }
 237
 238         walk->flags &= ~ABLKCIPHER_WALK_SLOW;
 239         src = dst = NULL;
 240
 241         bsize = min(walk->blocksize, n);
 242         n = scatterwalk_clamp(&walk->in, n);
 243         n = scatterwalk_clamp(&walk->out, n);
 244
 245         if (n < bsize ||
 246             !scatterwalk_aligned(&walk->in, alignmask) ||
 247             !scatterwalk_aligned(&walk->out, alignmask)) {
 248                 err = ablkcipher_next_slow(req, walk, bsize, alignmask,
 249                                            &src, &dst);
 250                 goto set_phys_lowmem;
 251         }
 252
 253         walk->nbytes = n;
 254
 255         return ablkcipher_next_fast(req, walk);
 256
 257 set_phys_lowmem:
 258         if (err >= 0) {
 259                 walk->src.page = virt_to_page(src);
 260                 walk->dst.page = virt_to_page(dst);
 261                 walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
 262                 walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
 263         }
 264
 265         return err;
 266 }
 267
 268 static int ablkcipher_walk_first(struct ablkcipher_request *req,
 269                                  struct ablkcipher_walk *walk)
 270 {
 271         struct crypto_tfm *tfm = req->base.tfm;
 272         unsigned int alignmask;
 273
 274         alignmask = crypto_tfm_alg_alignmask(tfm);
 275         if (WARN_ON_ONCE(in_irq()))
 276                 return -EDEADLK;
 277
 278         walk->iv = req->info;
 279         walk->nbytes = walk->total;
 280         if (unlikely(!walk->total))
 281                 return 0;
 282
 283         walk->iv_buffer = NULL;
 284         if (unlikely(((unsigned long)walk->iv & alignmask))) {
 285                 int err = ablkcipher_copy_iv(walk, tfm, alignmask);
 286
 287                 if (err)
 288                         return err;
 289         }
 290
 291         scatterwalk_start(&walk->in, walk->in.sg);
 292         scatterwalk_start(&walk->out, walk->out.sg);
 293
 294         return ablkcipher_walk_next(req, walk);
 295 }
 296
 297 int ablkcipher_walk_phys(struct ablkcipher_request *req,
 298                          struct ablkcipher_walk *walk)
 299 {
 300         walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
 301         return ablkcipher_walk_first(req, walk);
 302 }
 303 EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
 304
 305 static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
 306                             unsigned int keylen)
 307 {
 308         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
 309         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
 310         int ret;
 311         u8 *buffer, *alignbuffer;
 312         unsigned long absize;
 313
 314         absize = keylen + alignmask;
 315         buffer = kmalloc(absize, GFP_ATOMIC);
 316         if (!buffer)
 317                 return -ENOMEM;
 318
 319         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 320         memcpy(alignbuffer, key, keylen);
 321         ret = cipher->setkey(tfm, alignbuffer, keylen);
 322         memset(alignbuffer, 0, keylen);
 323         kfree(buffer);
 324         return ret;
 325 }
 326
 327 static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
 328                   unsigned int keylen)
 329 {
 330         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
 331         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
 332
 333         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 334                 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 335                 return -EINVAL;
 336         }
 337
 338         if ((unsigned long)key & alignmask)
 339                 return setkey_unaligned(tfm, key, keylen);
 340
 341         return cipher->setkey(tfm, key, keylen);
 342 }
 343
 344 static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
 345                                               u32 mask)
 346 {
 347         return alg->cra_ctxsize;
 348 }
 349
 350 static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
 351                                       u32 mask)
 352 {
 353         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 354         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 355
 356         if (alg->ivsize > PAGE_SIZE / 8)
 357                 return -EINVAL;
 358
 359         crt->setkey = setkey;
 360         crt->encrypt = alg->encrypt;
 361         crt->decrypt = alg->decrypt;
 362         crt->base = __crypto_ablkcipher_cast(tfm);
 363         crt->ivsize = alg->ivsize;
 364
 365         return 0;
 366 }
 367
 368 #ifdef CONFIG_NET
 369 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 370 {
 371         struct crypto_report_blkcipher rblkcipher;
 372
 373         strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
 374         strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
 375                 sizeof(rblkcipher.geniv));
 376
 377         rblkcipher.blocksize = alg->cra_blocksize;
 378         rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
 379         rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
 380         rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
 381
 382         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 383                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 384                 goto nla_put_failure;
 385         return 0;
 386
 387 nla_put_failure:
 388         return -EMSGSIZE;
 389 }
 390 #else
 391 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 392 {
 393         return -ENOSYS;
 394 }
 395 #endif
 396
 397 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 398         __maybe_unused;
 399 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 400 {
 401         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 402
 403         seq_printf(m, "type         : ablkcipher\n");
 404         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 405                                              "yes" : "no");
 406         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 407         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 408         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 409         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 410         seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
 411 }
 412
 413 const struct crypto_type crypto_ablkcipher_type = {
 414         .ctxsize = crypto_ablkcipher_ctxsize,
 415         .init = crypto_init_ablkcipher_ops,
 416 #ifdef CONFIG_PROC_FS
 417         .show = crypto_ablkcipher_show,
 418 #endif
 419         .report = crypto_ablkcipher_report,
 420 };
 421 EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
 422
 423 static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
 424                                       u32 mask)
 425 {
 426         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 427         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 428
 429         if (alg->ivsize > PAGE_SIZE / 8)
 430                 return -EINVAL;
 431
 432         crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
 433                       alg->setkey : setkey;
 434         crt->encrypt = alg->encrypt;
 435         crt->decrypt = alg->decrypt;
 436         crt->base = __crypto_ablkcipher_cast(tfm);
 437         crt->ivsize = alg->ivsize;
 438
 439         return 0;
 440 }
 441
 442 #ifdef CONFIG_NET
 443 static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 444 {
 445         struct crypto_report_blkcipher rblkcipher;
 446
 447         strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
 448         strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
 449                 sizeof(rblkcipher.geniv));
 450
 451         rblkcipher.blocksize = alg->cra_blocksize;
 452         rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
 453         rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
 454         rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
 455
 456         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 457                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 458                 goto nla_put_failure;
 459         return 0;
 460
 461 nla_put_failure:
 462         return -EMSGSIZE;
 463 }
 464 #else
 465 static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 466 {
 467         return -ENOSYS;
 468 }
 469 #endif
 470
 471 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 472         __maybe_unused;
 473 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 474 {
 475         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 476
 477         seq_printf(m, "type         : givcipher\n");
 478         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 479                                              "yes" : "no");
 480         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 481         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 482         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 483         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 484         seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
 485 }
 486
 487 const struct crypto_type crypto_givcipher_type = {
 488         .ctxsize = crypto_ablkcipher_ctxsize,
 489         .init = crypto_init_givcipher_ops,
 490 #ifdef CONFIG_PROC_FS
 491         .show = crypto_givcipher_show,
 492 #endif
 493         .report = crypto_givcipher_report,
 494 };
 495 EXPORT_SYMBOL_GPL(crypto_givcipher_type);