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0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Symmetric key cipher operations.
0004  *
0005  * Generic encrypt/decrypt wrapper for ciphers, handles operations across
0006  * multiple page boundaries by using temporary blocks.  In user context,
0007  * the kernel is given a chance to schedule us once per page.
0008  *
0009  * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
0010  */
0011 
0012 #include <crypto/internal/aead.h>
0013 #include <crypto/internal/cipher.h>
0014 #include <crypto/internal/skcipher.h>
0015 #include <crypto/scatterwalk.h>
0016 #include <linux/bug.h>
0017 #include <linux/cryptouser.h>
0018 #include <linux/compiler.h>
0019 #include <linux/list.h>
0020 #include <linux/module.h>
0021 #include <linux/rtnetlink.h>
0022 #include <linux/seq_file.h>
0023 #include <net/netlink.h>
0024 
0025 #include "internal.h"
0026 
0027 enum {
0028     SKCIPHER_WALK_PHYS = 1 << 0,
0029     SKCIPHER_WALK_SLOW = 1 << 1,
0030     SKCIPHER_WALK_COPY = 1 << 2,
0031     SKCIPHER_WALK_DIFF = 1 << 3,
0032     SKCIPHER_WALK_SLEEP = 1 << 4,
0033 };
0034 
0035 struct skcipher_walk_buffer {
0036     struct list_head entry;
0037     struct scatter_walk dst;
0038     unsigned int len;
0039     u8 *data;
0040     u8 buffer[];
0041 };
0042 
0043 static int skcipher_walk_next(struct skcipher_walk *walk);
0044 
0045 static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr)
0046 {
0047     if (PageHighMem(scatterwalk_page(walk)))
0048         kunmap_atomic(vaddr);
0049 }
0050 
0051 static inline void *skcipher_map(struct scatter_walk *walk)
0052 {
0053     struct page *page = scatterwalk_page(walk);
0054 
0055     return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) +
0056            offset_in_page(walk->offset);
0057 }
0058 
0059 static inline void skcipher_map_src(struct skcipher_walk *walk)
0060 {
0061     walk->src.virt.addr = skcipher_map(&walk->in);
0062 }
0063 
0064 static inline void skcipher_map_dst(struct skcipher_walk *walk)
0065 {
0066     walk->dst.virt.addr = skcipher_map(&walk->out);
0067 }
0068 
0069 static inline void skcipher_unmap_src(struct skcipher_walk *walk)
0070 {
0071     skcipher_unmap(&walk->in, walk->src.virt.addr);
0072 }
0073 
0074 static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
0075 {
0076     skcipher_unmap(&walk->out, walk->dst.virt.addr);
0077 }
0078 
0079 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
0080 {
0081     return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
0082 }
0083 
0084 /* Get a spot of the specified length that does not straddle a page.
0085  * The caller needs to ensure that there is enough space for this operation.
0086  */
0087 static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
0088 {
0089     u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
0090 
0091     return max(start, end_page);
0092 }
0093 
0094 static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
0095 {
0096     u8 *addr;
0097 
0098     addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
0099     addr = skcipher_get_spot(addr, bsize);
0100     scatterwalk_copychunks(addr, &walk->out, bsize,
0101                    (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
0102     return 0;
0103 }
0104 
0105 int skcipher_walk_done(struct skcipher_walk *walk, int err)
0106 {
0107     unsigned int n = walk->nbytes;
0108     unsigned int nbytes = 0;
0109 
0110     if (!n)
0111         goto finish;
0112 
0113     if (likely(err >= 0)) {
0114         n -= err;
0115         nbytes = walk->total - n;
0116     }
0117 
0118     if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
0119                     SKCIPHER_WALK_SLOW |
0120                     SKCIPHER_WALK_COPY |
0121                     SKCIPHER_WALK_DIFF)))) {
0122 unmap_src:
0123         skcipher_unmap_src(walk);
0124     } else if (walk->flags & SKCIPHER_WALK_DIFF) {
0125         skcipher_unmap_dst(walk);
0126         goto unmap_src;
0127     } else if (walk->flags & SKCIPHER_WALK_COPY) {
0128         skcipher_map_dst(walk);
0129         memcpy(walk->dst.virt.addr, walk->page, n);
0130         skcipher_unmap_dst(walk);
0131     } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
0132         if (err > 0) {
0133             /*
0134              * Didn't process all bytes.  Either the algorithm is
0135              * broken, or this was the last step and it turned out
0136              * the message wasn't evenly divisible into blocks but
0137              * the algorithm requires it.
0138              */
0139             err = -EINVAL;
0140             nbytes = 0;
0141         } else
0142             n = skcipher_done_slow(walk, n);
0143     }
0144 
0145     if (err > 0)
0146         err = 0;
0147 
0148     walk->total = nbytes;
0149     walk->nbytes = 0;
0150 
0151     scatterwalk_advance(&walk->in, n);
0152     scatterwalk_advance(&walk->out, n);
0153     scatterwalk_done(&walk->in, 0, nbytes);
0154     scatterwalk_done(&walk->out, 1, nbytes);
0155 
0156     if (nbytes) {
0157         crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
0158                  CRYPTO_TFM_REQ_MAY_SLEEP : 0);
0159         return skcipher_walk_next(walk);
0160     }
0161 
0162 finish:
0163     /* Short-circuit for the common/fast path. */
0164     if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
0165         goto out;
0166 
0167     if (walk->flags & SKCIPHER_WALK_PHYS)
0168         goto out;
0169 
0170     if (walk->iv != walk->oiv)
0171         memcpy(walk->oiv, walk->iv, walk->ivsize);
0172     if (walk->buffer != walk->page)
0173         kfree(walk->buffer);
0174     if (walk->page)
0175         free_page((unsigned long)walk->page);
0176 
0177 out:
0178     return err;
0179 }
0180 EXPORT_SYMBOL_GPL(skcipher_walk_done);
0181 
0182 void skcipher_walk_complete(struct skcipher_walk *walk, int err)
0183 {
0184     struct skcipher_walk_buffer *p, *tmp;
0185 
0186     list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
0187         u8 *data;
0188 
0189         if (err)
0190             goto done;
0191 
0192         data = p->data;
0193         if (!data) {
0194             data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
0195             data = skcipher_get_spot(data, walk->stride);
0196         }
0197 
0198         scatterwalk_copychunks(data, &p->dst, p->len, 1);
0199 
0200         if (offset_in_page(p->data) + p->len + walk->stride >
0201             PAGE_SIZE)
0202             free_page((unsigned long)p->data);
0203 
0204 done:
0205         list_del(&p->entry);
0206         kfree(p);
0207     }
0208 
0209     if (!err && walk->iv != walk->oiv)
0210         memcpy(walk->oiv, walk->iv, walk->ivsize);
0211     if (walk->buffer != walk->page)
0212         kfree(walk->buffer);
0213     if (walk->page)
0214         free_page((unsigned long)walk->page);
0215 }
0216 EXPORT_SYMBOL_GPL(skcipher_walk_complete);
0217 
0218 static void skcipher_queue_write(struct skcipher_walk *walk,
0219                  struct skcipher_walk_buffer *p)
0220 {
0221     p->dst = walk->out;
0222     list_add_tail(&p->entry, &walk->buffers);
0223 }
0224 
0225 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
0226 {
0227     bool phys = walk->flags & SKCIPHER_WALK_PHYS;
0228     unsigned alignmask = walk->alignmask;
0229     struct skcipher_walk_buffer *p;
0230     unsigned a;
0231     unsigned n;
0232     u8 *buffer;
0233     void *v;
0234 
0235     if (!phys) {
0236         if (!walk->buffer)
0237             walk->buffer = walk->page;
0238         buffer = walk->buffer;
0239         if (buffer)
0240             goto ok;
0241     }
0242 
0243     /* Start with the minimum alignment of kmalloc. */
0244     a = crypto_tfm_ctx_alignment() - 1;
0245     n = bsize;
0246 
0247     if (phys) {
0248         /* Calculate the minimum alignment of p->buffer. */
0249         a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
0250         n += sizeof(*p);
0251     }
0252 
0253     /* Minimum size to align p->buffer by alignmask. */
0254     n += alignmask & ~a;
0255 
0256     /* Minimum size to ensure p->buffer does not straddle a page. */
0257     n += (bsize - 1) & ~(alignmask | a);
0258 
0259     v = kzalloc(n, skcipher_walk_gfp(walk));
0260     if (!v)
0261         return skcipher_walk_done(walk, -ENOMEM);
0262 
0263     if (phys) {
0264         p = v;
0265         p->len = bsize;
0266         skcipher_queue_write(walk, p);
0267         buffer = p->buffer;
0268     } else {
0269         walk->buffer = v;
0270         buffer = v;
0271     }
0272 
0273 ok:
0274     walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
0275     walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
0276     walk->src.virt.addr = walk->dst.virt.addr;
0277 
0278     scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
0279 
0280     walk->nbytes = bsize;
0281     walk->flags |= SKCIPHER_WALK_SLOW;
0282 
0283     return 0;
0284 }
0285 
0286 static int skcipher_next_copy(struct skcipher_walk *walk)
0287 {
0288     struct skcipher_walk_buffer *p;
0289     u8 *tmp = walk->page;
0290 
0291     skcipher_map_src(walk);
0292     memcpy(tmp, walk->src.virt.addr, walk->nbytes);
0293     skcipher_unmap_src(walk);
0294 
0295     walk->src.virt.addr = tmp;
0296     walk->dst.virt.addr = tmp;
0297 
0298     if (!(walk->flags & SKCIPHER_WALK_PHYS))
0299         return 0;
0300 
0301     p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
0302     if (!p)
0303         return -ENOMEM;
0304 
0305     p->data = walk->page;
0306     p->len = walk->nbytes;
0307     skcipher_queue_write(walk, p);
0308 
0309     if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
0310         PAGE_SIZE)
0311         walk->page = NULL;
0312     else
0313         walk->page += walk->nbytes;
0314 
0315     return 0;
0316 }
0317 
0318 static int skcipher_next_fast(struct skcipher_walk *walk)
0319 {
0320     unsigned long diff;
0321 
0322     walk->src.phys.page = scatterwalk_page(&walk->in);
0323     walk->src.phys.offset = offset_in_page(walk->in.offset);
0324     walk->dst.phys.page = scatterwalk_page(&walk->out);
0325     walk->dst.phys.offset = offset_in_page(walk->out.offset);
0326 
0327     if (walk->flags & SKCIPHER_WALK_PHYS)
0328         return 0;
0329 
0330     diff = walk->src.phys.offset - walk->dst.phys.offset;
0331     diff |= walk->src.virt.page - walk->dst.virt.page;
0332 
0333     skcipher_map_src(walk);
0334     walk->dst.virt.addr = walk->src.virt.addr;
0335 
0336     if (diff) {
0337         walk->flags |= SKCIPHER_WALK_DIFF;
0338         skcipher_map_dst(walk);
0339     }
0340 
0341     return 0;
0342 }
0343 
0344 static int skcipher_walk_next(struct skcipher_walk *walk)
0345 {
0346     unsigned int bsize;
0347     unsigned int n;
0348     int err;
0349 
0350     walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
0351              SKCIPHER_WALK_DIFF);
0352 
0353     n = walk->total;
0354     bsize = min(walk->stride, max(n, walk->blocksize));
0355     n = scatterwalk_clamp(&walk->in, n);
0356     n = scatterwalk_clamp(&walk->out, n);
0357 
0358     if (unlikely(n < bsize)) {
0359         if (unlikely(walk->total < walk->blocksize))
0360             return skcipher_walk_done(walk, -EINVAL);
0361 
0362 slow_path:
0363         err = skcipher_next_slow(walk, bsize);
0364         goto set_phys_lowmem;
0365     }
0366 
0367     if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
0368         if (!walk->page) {
0369             gfp_t gfp = skcipher_walk_gfp(walk);
0370 
0371             walk->page = (void *)__get_free_page(gfp);
0372             if (!walk->page)
0373                 goto slow_path;
0374         }
0375 
0376         walk->nbytes = min_t(unsigned, n,
0377                      PAGE_SIZE - offset_in_page(walk->page));
0378         walk->flags |= SKCIPHER_WALK_COPY;
0379         err = skcipher_next_copy(walk);
0380         goto set_phys_lowmem;
0381     }
0382 
0383     walk->nbytes = n;
0384 
0385     return skcipher_next_fast(walk);
0386 
0387 set_phys_lowmem:
0388     if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) {
0389         walk->src.phys.page = virt_to_page(walk->src.virt.addr);
0390         walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
0391         walk->src.phys.offset &= PAGE_SIZE - 1;
0392         walk->dst.phys.offset &= PAGE_SIZE - 1;
0393     }
0394     return err;
0395 }
0396 
0397 static int skcipher_copy_iv(struct skcipher_walk *walk)
0398 {
0399     unsigned a = crypto_tfm_ctx_alignment() - 1;
0400     unsigned alignmask = walk->alignmask;
0401     unsigned ivsize = walk->ivsize;
0402     unsigned bs = walk->stride;
0403     unsigned aligned_bs;
0404     unsigned size;
0405     u8 *iv;
0406 
0407     aligned_bs = ALIGN(bs, alignmask + 1);
0408 
0409     /* Minimum size to align buffer by alignmask. */
0410     size = alignmask & ~a;
0411 
0412     if (walk->flags & SKCIPHER_WALK_PHYS)
0413         size += ivsize;
0414     else {
0415         size += aligned_bs + ivsize;
0416 
0417         /* Minimum size to ensure buffer does not straddle a page. */
0418         size += (bs - 1) & ~(alignmask | a);
0419     }
0420 
0421     walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
0422     if (!walk->buffer)
0423         return -ENOMEM;
0424 
0425     iv = PTR_ALIGN(walk->buffer, alignmask + 1);
0426     iv = skcipher_get_spot(iv, bs) + aligned_bs;
0427 
0428     walk->iv = memcpy(iv, walk->iv, walk->ivsize);
0429     return 0;
0430 }
0431 
0432 static int skcipher_walk_first(struct skcipher_walk *walk)
0433 {
0434     if (WARN_ON_ONCE(in_hardirq()))
0435         return -EDEADLK;
0436 
0437     walk->buffer = NULL;
0438     if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
0439         int err = skcipher_copy_iv(walk);
0440         if (err)
0441             return err;
0442     }
0443 
0444     walk->page = NULL;
0445 
0446     return skcipher_walk_next(walk);
0447 }
0448 
0449 static int skcipher_walk_skcipher(struct skcipher_walk *walk,
0450                   struct skcipher_request *req)
0451 {
0452     struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
0453 
0454     walk->total = req->cryptlen;
0455     walk->nbytes = 0;
0456     walk->iv = req->iv;
0457     walk->oiv = req->iv;
0458 
0459     if (unlikely(!walk->total))
0460         return 0;
0461 
0462     scatterwalk_start(&walk->in, req->src);
0463     scatterwalk_start(&walk->out, req->dst);
0464 
0465     walk->flags &= ~SKCIPHER_WALK_SLEEP;
0466     walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
0467                SKCIPHER_WALK_SLEEP : 0;
0468 
0469     walk->blocksize = crypto_skcipher_blocksize(tfm);
0470     walk->stride = crypto_skcipher_walksize(tfm);
0471     walk->ivsize = crypto_skcipher_ivsize(tfm);
0472     walk->alignmask = crypto_skcipher_alignmask(tfm);
0473 
0474     return skcipher_walk_first(walk);
0475 }
0476 
0477 int skcipher_walk_virt(struct skcipher_walk *walk,
0478                struct skcipher_request *req, bool atomic)
0479 {
0480     int err;
0481 
0482     might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
0483 
0484     walk->flags &= ~SKCIPHER_WALK_PHYS;
0485 
0486     err = skcipher_walk_skcipher(walk, req);
0487 
0488     walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
0489 
0490     return err;
0491 }
0492 EXPORT_SYMBOL_GPL(skcipher_walk_virt);
0493 
0494 int skcipher_walk_async(struct skcipher_walk *walk,
0495             struct skcipher_request *req)
0496 {
0497     walk->flags |= SKCIPHER_WALK_PHYS;
0498 
0499     INIT_LIST_HEAD(&walk->buffers);
0500 
0501     return skcipher_walk_skcipher(walk, req);
0502 }
0503 EXPORT_SYMBOL_GPL(skcipher_walk_async);
0504 
0505 static int skcipher_walk_aead_common(struct skcipher_walk *walk,
0506                      struct aead_request *req, bool atomic)
0507 {
0508     struct crypto_aead *tfm = crypto_aead_reqtfm(req);
0509     int err;
0510 
0511     walk->nbytes = 0;
0512     walk->iv = req->iv;
0513     walk->oiv = req->iv;
0514 
0515     if (unlikely(!walk->total))
0516         return 0;
0517 
0518     walk->flags &= ~SKCIPHER_WALK_PHYS;
0519 
0520     scatterwalk_start(&walk->in, req->src);
0521     scatterwalk_start(&walk->out, req->dst);
0522 
0523     scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
0524     scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
0525 
0526     scatterwalk_done(&walk->in, 0, walk->total);
0527     scatterwalk_done(&walk->out, 0, walk->total);
0528 
0529     if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
0530         walk->flags |= SKCIPHER_WALK_SLEEP;
0531     else
0532         walk->flags &= ~SKCIPHER_WALK_SLEEP;
0533 
0534     walk->blocksize = crypto_aead_blocksize(tfm);
0535     walk->stride = crypto_aead_chunksize(tfm);
0536     walk->ivsize = crypto_aead_ivsize(tfm);
0537     walk->alignmask = crypto_aead_alignmask(tfm);
0538 
0539     err = skcipher_walk_first(walk);
0540 
0541     if (atomic)
0542         walk->flags &= ~SKCIPHER_WALK_SLEEP;
0543 
0544     return err;
0545 }
0546 
0547 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
0548                    struct aead_request *req, bool atomic)
0549 {
0550     walk->total = req->cryptlen;
0551 
0552     return skcipher_walk_aead_common(walk, req, atomic);
0553 }
0554 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
0555 
0556 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
0557                    struct aead_request *req, bool atomic)
0558 {
0559     struct crypto_aead *tfm = crypto_aead_reqtfm(req);
0560 
0561     walk->total = req->cryptlen - crypto_aead_authsize(tfm);
0562 
0563     return skcipher_walk_aead_common(walk, req, atomic);
0564 }
0565 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
0566 
0567 static void skcipher_set_needkey(struct crypto_skcipher *tfm)
0568 {
0569     if (crypto_skcipher_max_keysize(tfm) != 0)
0570         crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
0571 }
0572 
0573 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
0574                      const u8 *key, unsigned int keylen)
0575 {
0576     unsigned long alignmask = crypto_skcipher_alignmask(tfm);
0577     struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
0578     u8 *buffer, *alignbuffer;
0579     unsigned long absize;
0580     int ret;
0581 
0582     absize = keylen + alignmask;
0583     buffer = kmalloc(absize, GFP_ATOMIC);
0584     if (!buffer)
0585         return -ENOMEM;
0586 
0587     alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
0588     memcpy(alignbuffer, key, keylen);
0589     ret = cipher->setkey(tfm, alignbuffer, keylen);
0590     kfree_sensitive(buffer);
0591     return ret;
0592 }
0593 
0594 int crypto_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
0595                unsigned int keylen)
0596 {
0597     struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
0598     unsigned long alignmask = crypto_skcipher_alignmask(tfm);
0599     int err;
0600 
0601     if (keylen < cipher->min_keysize || keylen > cipher->max_keysize)
0602         return -EINVAL;
0603 
0604     if ((unsigned long)key & alignmask)
0605         err = skcipher_setkey_unaligned(tfm, key, keylen);
0606     else
0607         err = cipher->setkey(tfm, key, keylen);
0608 
0609     if (unlikely(err)) {
0610         skcipher_set_needkey(tfm);
0611         return err;
0612     }
0613 
0614     crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
0615     return 0;
0616 }
0617 EXPORT_SYMBOL_GPL(crypto_skcipher_setkey);
0618 
0619 int crypto_skcipher_encrypt(struct skcipher_request *req)
0620 {
0621     struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
0622     struct crypto_alg *alg = tfm->base.__crt_alg;
0623     unsigned int cryptlen = req->cryptlen;
0624     int ret;
0625 
0626     crypto_stats_get(alg);
0627     if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
0628         ret = -ENOKEY;
0629     else
0630         ret = crypto_skcipher_alg(tfm)->encrypt(req);
0631     crypto_stats_skcipher_encrypt(cryptlen, ret, alg);
0632     return ret;
0633 }
0634 EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt);
0635 
0636 int crypto_skcipher_decrypt(struct skcipher_request *req)
0637 {
0638     struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
0639     struct crypto_alg *alg = tfm->base.__crt_alg;
0640     unsigned int cryptlen = req->cryptlen;
0641     int ret;
0642 
0643     crypto_stats_get(alg);
0644     if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
0645         ret = -ENOKEY;
0646     else
0647         ret = crypto_skcipher_alg(tfm)->decrypt(req);
0648     crypto_stats_skcipher_decrypt(cryptlen, ret, alg);
0649     return ret;
0650 }
0651 EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt);
0652 
0653 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
0654 {
0655     struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
0656     struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
0657 
0658     alg->exit(skcipher);
0659 }
0660 
0661 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
0662 {
0663     struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
0664     struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
0665 
0666     skcipher_set_needkey(skcipher);
0667 
0668     if (alg->exit)
0669         skcipher->base.exit = crypto_skcipher_exit_tfm;
0670 
0671     if (alg->init)
0672         return alg->init(skcipher);
0673 
0674     return 0;
0675 }
0676 
0677 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
0678 {
0679     struct skcipher_instance *skcipher =
0680         container_of(inst, struct skcipher_instance, s.base);
0681 
0682     skcipher->free(skcipher);
0683 }
0684 
0685 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
0686     __maybe_unused;
0687 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
0688 {
0689     struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
0690                              base);
0691 
0692     seq_printf(m, "type         : skcipher\n");
0693     seq_printf(m, "async        : %s\n",
0694            alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
0695     seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
0696     seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
0697     seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
0698     seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
0699     seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
0700     seq_printf(m, "walksize     : %u\n", skcipher->walksize);
0701 }
0702 
0703 #ifdef CONFIG_NET
0704 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
0705 {
0706     struct crypto_report_blkcipher rblkcipher;
0707     struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
0708                              base);
0709 
0710     memset(&rblkcipher, 0, sizeof(rblkcipher));
0711 
0712     strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
0713     strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
0714 
0715     rblkcipher.blocksize = alg->cra_blocksize;
0716     rblkcipher.min_keysize = skcipher->min_keysize;
0717     rblkcipher.max_keysize = skcipher->max_keysize;
0718     rblkcipher.ivsize = skcipher->ivsize;
0719 
0720     return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
0721                sizeof(rblkcipher), &rblkcipher);
0722 }
0723 #else
0724 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
0725 {
0726     return -ENOSYS;
0727 }
0728 #endif
0729 
0730 static const struct crypto_type crypto_skcipher_type = {
0731     .extsize = crypto_alg_extsize,
0732     .init_tfm = crypto_skcipher_init_tfm,
0733     .free = crypto_skcipher_free_instance,
0734 #ifdef CONFIG_PROC_FS
0735     .show = crypto_skcipher_show,
0736 #endif
0737     .report = crypto_skcipher_report,
0738     .maskclear = ~CRYPTO_ALG_TYPE_MASK,
0739     .maskset = CRYPTO_ALG_TYPE_MASK,
0740     .type = CRYPTO_ALG_TYPE_SKCIPHER,
0741     .tfmsize = offsetof(struct crypto_skcipher, base),
0742 };
0743 
0744 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
0745              struct crypto_instance *inst,
0746              const char *name, u32 type, u32 mask)
0747 {
0748     spawn->base.frontend = &crypto_skcipher_type;
0749     return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
0750 }
0751 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
0752 
0753 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
0754                           u32 type, u32 mask)
0755 {
0756     return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
0757 }
0758 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
0759 
0760 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
0761                 const char *alg_name, u32 type, u32 mask)
0762 {
0763     struct crypto_skcipher *tfm;
0764 
0765     /* Only sync algorithms allowed. */
0766     mask |= CRYPTO_ALG_ASYNC;
0767 
0768     tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
0769 
0770     /*
0771      * Make sure we do not allocate something that might get used with
0772      * an on-stack request: check the request size.
0773      */
0774     if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
0775                     MAX_SYNC_SKCIPHER_REQSIZE)) {
0776         crypto_free_skcipher(tfm);
0777         return ERR_PTR(-EINVAL);
0778     }
0779 
0780     return (struct crypto_sync_skcipher *)tfm;
0781 }
0782 EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);
0783 
0784 int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask)
0785 {
0786     return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask);
0787 }
0788 EXPORT_SYMBOL_GPL(crypto_has_skcipher);
0789 
0790 static int skcipher_prepare_alg(struct skcipher_alg *alg)
0791 {
0792     struct crypto_alg *base = &alg->base;
0793 
0794     if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
0795         alg->walksize > PAGE_SIZE / 8)
0796         return -EINVAL;
0797 
0798     if (!alg->chunksize)
0799         alg->chunksize = base->cra_blocksize;
0800     if (!alg->walksize)
0801         alg->walksize = alg->chunksize;
0802 
0803     base->cra_type = &crypto_skcipher_type;
0804     base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
0805     base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
0806 
0807     return 0;
0808 }
0809 
0810 int crypto_register_skcipher(struct skcipher_alg *alg)
0811 {
0812     struct crypto_alg *base = &alg->base;
0813     int err;
0814 
0815     err = skcipher_prepare_alg(alg);
0816     if (err)
0817         return err;
0818 
0819     return crypto_register_alg(base);
0820 }
0821 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
0822 
0823 void crypto_unregister_skcipher(struct skcipher_alg *alg)
0824 {
0825     crypto_unregister_alg(&alg->base);
0826 }
0827 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
0828 
0829 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
0830 {
0831     int i, ret;
0832 
0833     for (i = 0; i < count; i++) {
0834         ret = crypto_register_skcipher(&algs[i]);
0835         if (ret)
0836             goto err;
0837     }
0838 
0839     return 0;
0840 
0841 err:
0842     for (--i; i >= 0; --i)
0843         crypto_unregister_skcipher(&algs[i]);
0844 
0845     return ret;
0846 }
0847 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
0848 
0849 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
0850 {
0851     int i;
0852 
0853     for (i = count - 1; i >= 0; --i)
0854         crypto_unregister_skcipher(&algs[i]);
0855 }
0856 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
0857 
0858 int skcipher_register_instance(struct crypto_template *tmpl,
0859                struct skcipher_instance *inst)
0860 {
0861     int err;
0862 
0863     if (WARN_ON(!inst->free))
0864         return -EINVAL;
0865 
0866     err = skcipher_prepare_alg(&inst->alg);
0867     if (err)
0868         return err;
0869 
0870     return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
0871 }
0872 EXPORT_SYMBOL_GPL(skcipher_register_instance);
0873 
0874 static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key,
0875                   unsigned int keylen)
0876 {
0877     struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
0878 
0879     crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
0880     crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) &
0881                 CRYPTO_TFM_REQ_MASK);
0882     return crypto_cipher_setkey(cipher, key, keylen);
0883 }
0884 
0885 static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
0886 {
0887     struct skcipher_instance *inst = skcipher_alg_instance(tfm);
0888     struct crypto_cipher_spawn *spawn = skcipher_instance_ctx(inst);
0889     struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
0890     struct crypto_cipher *cipher;
0891 
0892     cipher = crypto_spawn_cipher(spawn);
0893     if (IS_ERR(cipher))
0894         return PTR_ERR(cipher);
0895 
0896     ctx->cipher = cipher;
0897     return 0;
0898 }
0899 
0900 static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm)
0901 {
0902     struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
0903 
0904     crypto_free_cipher(ctx->cipher);
0905 }
0906 
0907 static void skcipher_free_instance_simple(struct skcipher_instance *inst)
0908 {
0909     crypto_drop_cipher(skcipher_instance_ctx(inst));
0910     kfree(inst);
0911 }
0912 
0913 /**
0914  * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode
0915  *
0916  * Allocate an skcipher_instance for a simple block cipher mode of operation,
0917  * e.g. cbc or ecb.  The instance context will have just a single crypto_spawn,
0918  * that for the underlying cipher.  The {min,max}_keysize, ivsize, blocksize,
0919  * alignmask, and priority are set from the underlying cipher but can be
0920  * overridden if needed.  The tfm context defaults to skcipher_ctx_simple, and
0921  * default ->setkey(), ->init(), and ->exit() methods are installed.
0922  *
0923  * @tmpl: the template being instantiated
0924  * @tb: the template parameters
0925  *
0926  * Return: a pointer to the new instance, or an ERR_PTR().  The caller still
0927  *     needs to register the instance.
0928  */
0929 struct skcipher_instance *skcipher_alloc_instance_simple(
0930     struct crypto_template *tmpl, struct rtattr **tb)
0931 {
0932     u32 mask;
0933     struct skcipher_instance *inst;
0934     struct crypto_cipher_spawn *spawn;
0935     struct crypto_alg *cipher_alg;
0936     int err;
0937 
0938     err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
0939     if (err)
0940         return ERR_PTR(err);
0941 
0942     inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
0943     if (!inst)
0944         return ERR_PTR(-ENOMEM);
0945     spawn = skcipher_instance_ctx(inst);
0946 
0947     err = crypto_grab_cipher(spawn, skcipher_crypto_instance(inst),
0948                  crypto_attr_alg_name(tb[1]), 0, mask);
0949     if (err)
0950         goto err_free_inst;
0951     cipher_alg = crypto_spawn_cipher_alg(spawn);
0952 
0953     err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name,
0954                   cipher_alg);
0955     if (err)
0956         goto err_free_inst;
0957 
0958     inst->free = skcipher_free_instance_simple;
0959 
0960     /* Default algorithm properties, can be overridden */
0961     inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize;
0962     inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask;
0963     inst->alg.base.cra_priority = cipher_alg->cra_priority;
0964     inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
0965     inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
0966     inst->alg.ivsize = cipher_alg->cra_blocksize;
0967 
0968     /* Use skcipher_ctx_simple by default, can be overridden */
0969     inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple);
0970     inst->alg.setkey = skcipher_setkey_simple;
0971     inst->alg.init = skcipher_init_tfm_simple;
0972     inst->alg.exit = skcipher_exit_tfm_simple;
0973 
0974     return inst;
0975 
0976 err_free_inst:
0977     skcipher_free_instance_simple(inst);
0978     return ERR_PTR(err);
0979 }
0980 EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);
0981 
0982 MODULE_LICENSE("GPL");
0983 MODULE_DESCRIPTION("Symmetric key cipher type");
0984 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
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