blkcipher.c

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    1 /*
    2  * Block chaining cipher operations.
    3  * 
    4  * Generic encrypt/decrypt wrapper for ciphers, handles operations across
    5  * multiple page boundaries by using temporary blocks.  In user context,
    6  * the kernel is given a chance to schedule us once per page.
    7  *
    8  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
    9  *
   10  * This program is free software; you can redistribute it and/or modify it
   11  * under the terms of the GNU General Public License as published by the Free
   12  * Software Foundation; either version 2 of the License, or (at your option) 
   13  * any later version.
   14  *
   15  */
   16 
   17 #include <crypto/internal/skcipher.h>
   18 #include <crypto/scatterwalk.h>
   19 #include <linux/errno.h>
   20 #include <linux/hardirq.h>
   21 #include <linux/kernel.h>
   22 #include <linux/module.h>
   23 #include <linux/scatterlist.h>
   24 #include <linux/seq_file.h>
   25 #include <linux/slab.h>
   26 #include <linux/string.h>
   27 #include <linux/cryptouser.h>
   28 #include <net/netlink.h>
   29 
   30 #include "internal.h"
   31 
   32 enum {
   33         BLKCIPHER_WALK_PHYS = 1 << 0,
   34         BLKCIPHER_WALK_SLOW = 1 << 1,
   35         BLKCIPHER_WALK_COPY = 1 << 2,
   36         BLKCIPHER_WALK_DIFF = 1 << 3,
   37 };
   38 
   39 static int blkcipher_walk_next(struct blkcipher_desc *desc,
   40                                struct blkcipher_walk *walk);
   41 static int blkcipher_walk_first(struct blkcipher_desc *desc,
   42                                 struct blkcipher_walk *walk);
   43 
   44 static inline void blkcipher_map_src(struct blkcipher_walk *walk)
   45 {
   46         walk->src.virt.addr = scatterwalk_map(&walk->in);
   47 }
   48 
   49 static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
   50 {
   51         walk->dst.virt.addr = scatterwalk_map(&walk->out);
   52 }
   53 
   54 static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
   55 {
   56         scatterwalk_unmap(walk->src.virt.addr);
   57 }
   58 
   59 static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
   60 {
   61         scatterwalk_unmap(walk->dst.virt.addr);
   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 *blkcipher_get_spot(u8 *start, unsigned int len)
   68 {
   69         u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
   70         return max(start, end_page);
   71 }
   72 
   73 static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
   74                                                struct blkcipher_walk *walk,
   75                                                unsigned int bsize)
   76 {
   77         u8 *addr;
   78         unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
   79 
   80         addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
   81         addr = blkcipher_get_spot(addr, bsize);
   82         scatterwalk_copychunks(addr, &walk->out, bsize, 1);
   83         return bsize;
   84 }
   85 
   86 static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
   87                                                unsigned int n)
   88 {
   89         if (walk->flags & BLKCIPHER_WALK_COPY) {
   90                 blkcipher_map_dst(walk);
   91                 memcpy(walk->dst.virt.addr, walk->page, n);
   92                 blkcipher_unmap_dst(walk);
   93         } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
   94                 if (walk->flags & BLKCIPHER_WALK_DIFF)
   95                         blkcipher_unmap_dst(walk);
   96                 blkcipher_unmap_src(walk);
   97         }
   98 
   99         scatterwalk_advance(&walk->in, n);
  100         scatterwalk_advance(&walk->out, n);
  101 
  102         return n;
  103 }
  104 
  105 int blkcipher_walk_done(struct blkcipher_desc *desc,
  106                         struct blkcipher_walk *walk, int err)
  107 {
  108         struct crypto_blkcipher *tfm = desc->tfm;
  109         unsigned int nbytes = 0;
  110 
  111         if (likely(err >= 0)) {
  112                 unsigned int n = walk->nbytes - err;
  113 
  114                 if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
  115                         n = blkcipher_done_fast(walk, n);
  116                 else if (WARN_ON(err)) {
  117                         err = -EINVAL;
  118                         goto err;
  119                 } else
  120                         n = blkcipher_done_slow(tfm, walk, n);
  121 
  122                 nbytes = walk->total - n;
  123                 err = 0;
  124         }
  125 
  126         scatterwalk_done(&walk->in, 0, nbytes);
  127         scatterwalk_done(&walk->out, 1, nbytes);
  128 
  129 err:
  130         walk->total = nbytes;
  131         walk->nbytes = nbytes;
  132 
  133         if (nbytes) {
  134                 crypto_yield(desc->flags);
  135                 return blkcipher_walk_next(desc, walk);
  136         }
  137 
  138         if (walk->iv != desc->info)
  139                 memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
  140         if (walk->buffer != walk->page)
  141                 kfree(walk->buffer);
  142         if (walk->page)
  143                 free_page((unsigned long)walk->page);
  144 
  145         return err;
  146 }
  147 EXPORT_SYMBOL_GPL(blkcipher_walk_done);
  148 
  149 static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
  150                                       struct blkcipher_walk *walk,
  151                                       unsigned int bsize,
  152                                       unsigned int alignmask)
  153 {
  154         unsigned int n;
  155         unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
  156 
  157         if (walk->buffer)
  158                 goto ok;
  159 
  160         walk->buffer = walk->page;
  161         if (walk->buffer)
  162                 goto ok;
  163 
  164         n = aligned_bsize * 3 - (alignmask + 1) +
  165             (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
  166         walk->buffer = kmalloc(n, GFP_ATOMIC);
  167         if (!walk->buffer)
  168                 return blkcipher_walk_done(desc, walk, -ENOMEM);
  169 
  170 ok:
  171         walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
  172                                           alignmask + 1);
  173         walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
  174         walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
  175                                                  aligned_bsize, bsize);
  176 
  177         scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
  178 
  179         walk->nbytes = bsize;
  180         walk->flags |= BLKCIPHER_WALK_SLOW;
  181 
  182         return 0;
  183 }
  184 
  185 static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
  186 {
  187         u8 *tmp = walk->page;
  188 
  189         blkcipher_map_src(walk);
  190         memcpy(tmp, walk->src.virt.addr, walk->nbytes);
  191         blkcipher_unmap_src(walk);
  192 
  193         walk->src.virt.addr = tmp;
  194         walk->dst.virt.addr = tmp;
  195 
  196         return 0;
  197 }
  198 
  199 static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
  200                                       struct blkcipher_walk *walk)
  201 {
  202         unsigned long diff;
  203 
  204         walk->src.phys.page = scatterwalk_page(&walk->in);
  205         walk->src.phys.offset = offset_in_page(walk->in.offset);
  206         walk->dst.phys.page = scatterwalk_page(&walk->out);
  207         walk->dst.phys.offset = offset_in_page(walk->out.offset);
  208 
  209         if (walk->flags & BLKCIPHER_WALK_PHYS)
  210                 return 0;
  211 
  212         diff = walk->src.phys.offset - walk->dst.phys.offset;
  213         diff |= walk->src.virt.page - walk->dst.virt.page;
  214 
  215         blkcipher_map_src(walk);
  216         walk->dst.virt.addr = walk->src.virt.addr;
  217 
  218         if (diff) {
  219                 walk->flags |= BLKCIPHER_WALK_DIFF;
  220                 blkcipher_map_dst(walk);
  221         }
  222 
  223         return 0;
  224 }
  225 
  226 static int blkcipher_walk_next(struct blkcipher_desc *desc,
  227                                struct blkcipher_walk *walk)
  228 {
  229         struct crypto_blkcipher *tfm = desc->tfm;
  230         unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
  231         unsigned int bsize;
  232         unsigned int n;
  233         int err;
  234 
  235         n = walk->total;
  236         if (unlikely(n < crypto_blkcipher_blocksize(tfm))) {
  237                 desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
  238                 return blkcipher_walk_done(desc, walk, -EINVAL);
  239         }
  240 
  241         walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
  242                          BLKCIPHER_WALK_DIFF);
  243         if (!scatterwalk_aligned(&walk->in, alignmask) ||
  244             !scatterwalk_aligned(&walk->out, alignmask)) {
  245                 walk->flags |= BLKCIPHER_WALK_COPY;
  246                 if (!walk->page) {
  247                         walk->page = (void *)__get_free_page(GFP_ATOMIC);
  248                         if (!walk->page)
  249                                 n = 0;
  250                 }
  251         }
  252 
  253         bsize = min(walk->blocksize, n);
  254         n = scatterwalk_clamp(&walk->in, n);
  255         n = scatterwalk_clamp(&walk->out, n);
  256 
  257         if (unlikely(n < bsize)) {
  258                 err = blkcipher_next_slow(desc, walk, bsize, alignmask);
  259                 goto set_phys_lowmem;
  260         }
  261 
  262         walk->nbytes = n;
  263         if (walk->flags & BLKCIPHER_WALK_COPY) {
  264                 err = blkcipher_next_copy(walk);
  265                 goto set_phys_lowmem;
  266         }
  267 
  268         return blkcipher_next_fast(desc, walk);
  269 
  270 set_phys_lowmem:
  271         if (walk->flags & BLKCIPHER_WALK_PHYS) {
  272                 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
  273                 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
  274                 walk->src.phys.offset &= PAGE_SIZE - 1;
  275                 walk->dst.phys.offset &= PAGE_SIZE - 1;
  276         }
  277         return err;
  278 }
  279 
  280 static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
  281                                     struct crypto_blkcipher *tfm,
  282                                     unsigned int alignmask)
  283 {
  284         unsigned bs = walk->blocksize;
  285         unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
  286         unsigned aligned_bs = ALIGN(bs, alignmask + 1);
  287         unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
  288                             (alignmask + 1);
  289         u8 *iv;
  290 
  291         size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
  292         walk->buffer = kmalloc(size, GFP_ATOMIC);
  293         if (!walk->buffer)
  294                 return -ENOMEM;
  295 
  296         iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
  297         iv = blkcipher_get_spot(iv, bs) + aligned_bs;
  298         iv = blkcipher_get_spot(iv, bs) + aligned_bs;
  299         iv = blkcipher_get_spot(iv, ivsize);
  300 
  301         walk->iv = memcpy(iv, walk->iv, ivsize);
  302         return 0;
  303 }
  304 
  305 int blkcipher_walk_virt(struct blkcipher_desc *desc,
  306                         struct blkcipher_walk *walk)
  307 {
  308         walk->flags &= ~BLKCIPHER_WALK_PHYS;
  309         walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
  310         return blkcipher_walk_first(desc, walk);
  311 }
  312 EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
  313 
  314 int blkcipher_walk_phys(struct blkcipher_desc *desc,
  315                         struct blkcipher_walk *walk)
  316 {
  317         walk->flags |= BLKCIPHER_WALK_PHYS;
  318         walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
  319         return blkcipher_walk_first(desc, walk);
  320 }
  321 EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
  322 
  323 static int blkcipher_walk_first(struct blkcipher_desc *desc,
  324                                 struct blkcipher_walk *walk)
  325 {
  326         struct crypto_blkcipher *tfm = desc->tfm;
  327         unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
  328 
  329         if (WARN_ON_ONCE(in_irq()))
  330                 return -EDEADLK;
  331 
  332         walk->nbytes = walk->total;
  333         if (unlikely(!walk->total))
  334                 return 0;
  335 
  336         walk->buffer = NULL;
  337         walk->iv = desc->info;
  338         if (unlikely(((unsigned long)walk->iv & alignmask))) {
  339                 int err = blkcipher_copy_iv(walk, tfm, alignmask);
  340                 if (err)
  341                         return err;
  342         }
  343 
  344         scatterwalk_start(&walk->in, walk->in.sg);
  345         scatterwalk_start(&walk->out, walk->out.sg);
  346         walk->page = NULL;
  347 
  348         return blkcipher_walk_next(desc, walk);
  349 }
  350 
  351 int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
  352                               struct blkcipher_walk *walk,
  353                               unsigned int blocksize)
  354 {
  355         walk->flags &= ~BLKCIPHER_WALK_PHYS;
  356         walk->blocksize = blocksize;
  357         return blkcipher_walk_first(desc, walk);
  358 }
  359 EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
  360 
  361 static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
  362                             unsigned int keylen)
  363 {
  364         struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
  365         unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
  366         int ret;
  367         u8 *buffer, *alignbuffer;
  368         unsigned long absize;
  369 
  370         absize = keylen + alignmask;
  371         buffer = kmalloc(absize, GFP_ATOMIC);
  372         if (!buffer)
  373                 return -ENOMEM;
  374 
  375         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  376         memcpy(alignbuffer, key, keylen);
  377         ret = cipher->setkey(tfm, alignbuffer, keylen);
  378         memset(alignbuffer, 0, keylen);
  379         kfree(buffer);
  380         return ret;
  381 }
  382 
  383 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
  384 {
  385         struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
  386         unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
  387 
  388         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
  389                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
  390                 return -EINVAL;
  391         }
  392 
  393         if ((unsigned long)key & alignmask)
  394                 return setkey_unaligned(tfm, key, keylen);
  395 
  396         return cipher->setkey(tfm, key, keylen);
  397 }
  398 
  399 static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
  400                         unsigned int keylen)
  401 {
  402         return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
  403 }
  404 
  405 static int async_encrypt(struct ablkcipher_request *req)
  406 {
  407         struct crypto_tfm *tfm = req->base.tfm;
  408         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
  409         struct blkcipher_desc desc = {
  410                 .tfm = __crypto_blkcipher_cast(tfm),
  411                 .info = req->info,
  412                 .flags = req->base.flags,
  413         };
  414 
  415 
  416         return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
  417 }
  418 
  419 static int async_decrypt(struct ablkcipher_request *req)
  420 {
  421         struct crypto_tfm *tfm = req->base.tfm;
  422         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
  423         struct blkcipher_desc desc = {
  424                 .tfm = __crypto_blkcipher_cast(tfm),
  425                 .info = req->info,
  426                 .flags = req->base.flags,
  427         };
  428 
  429         return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
  430 }
  431 
  432 static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
  433                                              u32 mask)
  434 {
  435         struct blkcipher_alg *cipher = &alg->cra_blkcipher;
  436         unsigned int len = alg->cra_ctxsize;
  437 
  438         if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
  439             cipher->ivsize) {
  440                 len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
  441                 len += cipher->ivsize;
  442         }
  443 
  444         return len;
  445 }
  446 
  447 static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
  448 {
  449         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
  450         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
  451 
  452         crt->setkey = async_setkey;
  453         crt->encrypt = async_encrypt;
  454         crt->decrypt = async_decrypt;
  455         if (!alg->ivsize) {
  456                 crt->givencrypt = skcipher_null_givencrypt;
  457                 crt->givdecrypt = skcipher_null_givdecrypt;
  458         }
  459         crt->base = __crypto_ablkcipher_cast(tfm);
  460         crt->ivsize = alg->ivsize;
  461 
  462         return 0;
  463 }
  464 
  465 static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
  466 {
  467         struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
  468         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
  469         unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
  470         unsigned long addr;
  471 
  472         crt->setkey = setkey;
  473         crt->encrypt = alg->encrypt;
  474         crt->decrypt = alg->decrypt;
  475 
  476         addr = (unsigned long)crypto_tfm_ctx(tfm);
  477         addr = ALIGN(addr, align);
  478         addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
  479         crt->iv = (void *)addr;
  480 
  481         return 0;
  482 }
  483 
  484 static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
  485 {
  486         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
  487 
  488         if (alg->ivsize > PAGE_SIZE / 8)
  489                 return -EINVAL;
  490 
  491         if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
  492                 return crypto_init_blkcipher_ops_sync(tfm);
  493         else
  494                 return crypto_init_blkcipher_ops_async(tfm);
  495 }
  496 
  497 #ifdef CONFIG_NET
  498 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
  499 {
  500         struct crypto_report_blkcipher rblkcipher;
  501 
  502         snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "blkcipher");
  503         snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s",
  504                  alg->cra_blkcipher.geniv ?: "<default>");
  505 
  506         rblkcipher.blocksize = alg->cra_blocksize;
  507         rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
  508         rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
  509         rblkcipher.ivsize = alg->cra_blkcipher.ivsize;
  510 
  511         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
  512                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
  513                 goto nla_put_failure;
  514         return 0;
  515 
  516 nla_put_failure:
  517         return -EMSGSIZE;
  518 }
  519 #else
  520 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
  521 {
  522         return -ENOSYS;
  523 }
  524 #endif
  525 
  526 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
  527         __attribute__ ((unused));
  528 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
  529 {
  530         seq_printf(m, "type         : blkcipher\n");
  531         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
  532         seq_printf(m, "min keysize  : %u\n", alg->cra_blkcipher.min_keysize);
  533         seq_printf(m, "max keysize  : %u\n", alg->cra_blkcipher.max_keysize);
  534         seq_printf(m, "ivsize       : %u\n", alg->cra_blkcipher.ivsize);
  535         seq_printf(m, "geniv        : %s\n", alg->cra_blkcipher.geniv ?:
  536                                              "<default>");
  537 }
  538 
  539 const struct crypto_type crypto_blkcipher_type = {
  540         .ctxsize = crypto_blkcipher_ctxsize,
  541         .init = crypto_init_blkcipher_ops,
  542 #ifdef CONFIG_PROC_FS
  543         .show = crypto_blkcipher_show,
  544 #endif
  545         .report = crypto_blkcipher_report,
  546 };
  547 EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
  548 
  549 static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
  550                                 const char *name, u32 type, u32 mask)
  551 {
  552         struct crypto_alg *alg;
  553         int err;
  554 
  555         type = crypto_skcipher_type(type);
  556         mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;
  557 
  558         alg = crypto_alg_mod_lookup(name, type, mask);
  559         if (IS_ERR(alg))
  560                 return PTR_ERR(alg);
  561 
  562         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
  563         crypto_mod_put(alg);
  564         return err;
  565 }
  566 
  567 struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
  568                                              struct rtattr **tb, u32 type,
  569                                              u32 mask)
  570 {
  571         struct {
  572                 int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
  573                               unsigned int keylen);
  574                 int (*encrypt)(struct ablkcipher_request *req);
  575                 int (*decrypt)(struct ablkcipher_request *req);
  576 
  577                 unsigned int min_keysize;
  578                 unsigned int max_keysize;
  579                 unsigned int ivsize;
  580 
  581                 const char *geniv;
  582         } balg;
  583         const char *name;
  584         struct crypto_skcipher_spawn *spawn;
  585         struct crypto_attr_type *algt;
  586         struct crypto_instance *inst;
  587         struct crypto_alg *alg;
  588         int err;
  589 
  590         algt = crypto_get_attr_type(tb);
  591         err = PTR_ERR(algt);
  592         if (IS_ERR(algt))
  593                 return ERR_PTR(err);
  594 
  595         if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
  596             algt->mask)
  597                 return ERR_PTR(-EINVAL);
  598 
  599         name = crypto_attr_alg_name(tb[1]);
  600         err = PTR_ERR(name);
  601         if (IS_ERR(name))
  602                 return ERR_PTR(err);
  603 
  604         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
  605         if (!inst)
  606                 return ERR_PTR(-ENOMEM);
  607 
  608         spawn = crypto_instance_ctx(inst);
  609 
  610         /* Ignore async algorithms if necessary. */
  611         mask |= crypto_requires_sync(algt->type, algt->mask);
  612 
  613         crypto_set_skcipher_spawn(spawn, inst);
  614         err = crypto_grab_nivcipher(spawn, name, type, mask);
  615         if (err)
  616                 goto err_free_inst;
  617 
  618         alg = crypto_skcipher_spawn_alg(spawn);
  619 
  620         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
  621             CRYPTO_ALG_TYPE_BLKCIPHER) {
  622                 balg.ivsize = alg->cra_blkcipher.ivsize;
  623                 balg.min_keysize = alg->cra_blkcipher.min_keysize;
  624                 balg.max_keysize = alg->cra_blkcipher.max_keysize;
  625 
  626                 balg.setkey = async_setkey;
  627                 balg.encrypt = async_encrypt;
  628                 balg.decrypt = async_decrypt;
  629 
  630                 balg.geniv = alg->cra_blkcipher.geniv;
  631         } else {
  632                 balg.ivsize = alg->cra_ablkcipher.ivsize;
  633                 balg.min_keysize = alg->cra_ablkcipher.min_keysize;
  634                 balg.max_keysize = alg->cra_ablkcipher.max_keysize;
  635 
  636                 balg.setkey = alg->cra_ablkcipher.setkey;
  637                 balg.encrypt = alg->cra_ablkcipher.encrypt;
  638                 balg.decrypt = alg->cra_ablkcipher.decrypt;
  639 
  640                 balg.geniv = alg->cra_ablkcipher.geniv;
  641         }
  642 
  643         err = -EINVAL;
  644         if (!balg.ivsize)
  645                 goto err_drop_alg;
  646 
  647         /*
  648          * This is only true if we're constructing an algorithm with its
  649          * default IV generator.  For the default generator we elide the
  650          * template name and double-check the IV generator.
  651          */
  652         if (algt->mask & CRYPTO_ALG_GENIV) {
  653                 if (!balg.geniv)
  654                         balg.geniv = crypto_default_geniv(alg);
  655                 err = -EAGAIN;
  656                 if (strcmp(tmpl->name, balg.geniv))
  657                         goto err_drop_alg;
  658 
  659                 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
  660                 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
  661                        CRYPTO_MAX_ALG_NAME);
  662         } else {
  663                 err = -ENAMETOOLONG;
  664                 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
  665                              "%s(%s)", tmpl->name, alg->cra_name) >=
  666                     CRYPTO_MAX_ALG_NAME)
  667                         goto err_drop_alg;
  668                 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
  669                              "%s(%s)", tmpl->name, alg->cra_driver_name) >=
  670                     CRYPTO_MAX_ALG_NAME)
  671                         goto err_drop_alg;
  672         }
  673 
  674         inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
  675         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
  676         inst->alg.cra_priority = alg->cra_priority;
  677         inst->alg.cra_blocksize = alg->cra_blocksize;
  678         inst->alg.cra_alignmask = alg->cra_alignmask;
  679         inst->alg.cra_type = &crypto_givcipher_type;
  680 
  681         inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
  682         inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
  683         inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
  684         inst->alg.cra_ablkcipher.geniv = balg.geniv;
  685 
  686         inst->alg.cra_ablkcipher.setkey = balg.setkey;
  687         inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
  688         inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
  689 
  690 out:
  691         return inst;
  692 
  693 err_drop_alg:
  694         crypto_drop_skcipher(spawn);
  695 err_free_inst:
  696         kfree(inst);
  697         inst = ERR_PTR(err);
  698         goto out;
  699 }
  700 EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
  701 
  702 void skcipher_geniv_free(struct crypto_instance *inst)
  703 {
  704         crypto_drop_skcipher(crypto_instance_ctx(inst));
  705         kfree(inst);
  706 }
  707 EXPORT_SYMBOL_GPL(skcipher_geniv_free);
  708 
  709 int skcipher_geniv_init(struct crypto_tfm *tfm)
  710 {
  711         struct crypto_instance *inst = (void *)tfm->__crt_alg;
  712         struct crypto_ablkcipher *cipher;
  713 
  714         cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
  715         if (IS_ERR(cipher))
  716                 return PTR_ERR(cipher);
  717 
  718         tfm->crt_ablkcipher.base = cipher;
  719         tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
  720 
  721         return 0;
  722 }
  723 EXPORT_SYMBOL_GPL(skcipher_geniv_init);
  724 
  725 void skcipher_geniv_exit(struct crypto_tfm *tfm)
  726 {
  727         crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
  728 }
  729 EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
  730 
  731 MODULE_LICENSE("GPL");
  732 MODULE_DESCRIPTION("Generic block chaining cipher type");
Cache object: c0baedbcf7a493ba8bc0f527479a38a5
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FreeBSD/Linux Kernel Cross Reference sys/crypto/blkcipher.c

FreeBSD/Linux Kernel Cross Reference
sys/crypto/blkcipher.c
