Revision b3a9e3b9622ae10064826dccb4f7a52bd88c7407 authored by Linus Torvalds on 14 June 2020, 19:45:04 UTC, committed by Linus Torvalds on 14 June 2020, 19:45:04 UTC
1 parent 4a87b19
skcipher.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Symmetric key cipher operations.
*
* Generic encrypt/decrypt wrapper for ciphers, handles operations across
* multiple page boundaries by using temporary blocks. In user context,
* the kernel is given a chance to schedule us once per page.
*
* Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <linux/bug.h>
#include <linux/cryptouser.h>
#include <linux/compiler.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/seq_file.h>
#include <net/netlink.h>
#include "internal.h"
enum {
SKCIPHER_WALK_PHYS = 1 << 0,
SKCIPHER_WALK_SLOW = 1 << 1,
SKCIPHER_WALK_COPY = 1 << 2,
SKCIPHER_WALK_DIFF = 1 << 3,
SKCIPHER_WALK_SLEEP = 1 << 4,
};
struct skcipher_walk_buffer {
struct list_head entry;
struct scatter_walk dst;
unsigned int len;
u8 *data;
u8 buffer[];
};
static int skcipher_walk_next(struct skcipher_walk *walk);
static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr)
{
if (PageHighMem(scatterwalk_page(walk)))
kunmap_atomic(vaddr);
}
static inline void *skcipher_map(struct scatter_walk *walk)
{
struct page *page = scatterwalk_page(walk);
return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) +
offset_in_page(walk->offset);
}
static inline void skcipher_map_src(struct skcipher_walk *walk)
{
walk->src.virt.addr = skcipher_map(&walk->in);
}
static inline void skcipher_map_dst(struct skcipher_walk *walk)
{
walk->dst.virt.addr = skcipher_map(&walk->out);
}
static inline void skcipher_unmap_src(struct skcipher_walk *walk)
{
skcipher_unmap(&walk->in, walk->src.virt.addr);
}
static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
{
skcipher_unmap(&walk->out, walk->dst.virt.addr);
}
static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
{
return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
}
/* Get a spot of the specified length that does not straddle a page.
* The caller needs to ensure that there is enough space for this operation.
*/
static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
{
u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
return max(start, end_page);
}
static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
{
u8 *addr;
addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
addr = skcipher_get_spot(addr, bsize);
scatterwalk_copychunks(addr, &walk->out, bsize,
(walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
return 0;
}
int skcipher_walk_done(struct skcipher_walk *walk, int err)
{
unsigned int n = walk->nbytes;
unsigned int nbytes = 0;
if (!n)
goto finish;
if (likely(err >= 0)) {
n -= err;
nbytes = walk->total - n;
}
if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
SKCIPHER_WALK_SLOW |
SKCIPHER_WALK_COPY |
SKCIPHER_WALK_DIFF)))) {
unmap_src:
skcipher_unmap_src(walk);
} else if (walk->flags & SKCIPHER_WALK_DIFF) {
skcipher_unmap_dst(walk);
goto unmap_src;
} else if (walk->flags & SKCIPHER_WALK_COPY) {
skcipher_map_dst(walk);
memcpy(walk->dst.virt.addr, walk->page, n);
skcipher_unmap_dst(walk);
} else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
if (err > 0) {
/*
* Didn't process all bytes. Either the algorithm is
* broken, or this was the last step and it turned out
* the message wasn't evenly divisible into blocks but
* the algorithm requires it.
*/
err = -EINVAL;
nbytes = 0;
} else
n = skcipher_done_slow(walk, n);
}
if (err > 0)
err = 0;
walk->total = nbytes;
walk->nbytes = 0;
scatterwalk_advance(&walk->in, n);
scatterwalk_advance(&walk->out, n);
scatterwalk_done(&walk->in, 0, nbytes);
scatterwalk_done(&walk->out, 1, nbytes);
if (nbytes) {
crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
CRYPTO_TFM_REQ_MAY_SLEEP : 0);
return skcipher_walk_next(walk);
}
finish:
/* Short-circuit for the common/fast path. */
if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
goto out;
if (walk->flags & SKCIPHER_WALK_PHYS)
goto out;
if (walk->iv != walk->oiv)
memcpy(walk->oiv, walk->iv, walk->ivsize);
if (walk->buffer != walk->page)
kfree(walk->buffer);
if (walk->page)
free_page((unsigned long)walk->page);
out:
return err;
}
EXPORT_SYMBOL_GPL(skcipher_walk_done);
void skcipher_walk_complete(struct skcipher_walk *walk, int err)
{
struct skcipher_walk_buffer *p, *tmp;
list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
u8 *data;
if (err)
goto done;
data = p->data;
if (!data) {
data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
data = skcipher_get_spot(data, walk->stride);
}
scatterwalk_copychunks(data, &p->dst, p->len, 1);
if (offset_in_page(p->data) + p->len + walk->stride >
PAGE_SIZE)
free_page((unsigned long)p->data);
done:
list_del(&p->entry);
kfree(p);
}
if (!err && walk->iv != walk->oiv)
memcpy(walk->oiv, walk->iv, walk->ivsize);
if (walk->buffer != walk->page)
kfree(walk->buffer);
if (walk->page)
free_page((unsigned long)walk->page);
}
EXPORT_SYMBOL_GPL(skcipher_walk_complete);
static void skcipher_queue_write(struct skcipher_walk *walk,
struct skcipher_walk_buffer *p)
{
p->dst = walk->out;
list_add_tail(&p->entry, &walk->buffers);
}
static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
{
bool phys = walk->flags & SKCIPHER_WALK_PHYS;
unsigned alignmask = walk->alignmask;
struct skcipher_walk_buffer *p;
unsigned a;
unsigned n;
u8 *buffer;
void *v;
if (!phys) {
if (!walk->buffer)
walk->buffer = walk->page;
buffer = walk->buffer;
if (buffer)
goto ok;
}
/* Start with the minimum alignment of kmalloc. */
a = crypto_tfm_ctx_alignment() - 1;
n = bsize;
if (phys) {
/* Calculate the minimum alignment of p->buffer. */
a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
n += sizeof(*p);
}
/* Minimum size to align p->buffer by alignmask. */
n += alignmask & ~a;
/* Minimum size to ensure p->buffer does not straddle a page. */
n += (bsize - 1) & ~(alignmask | a);
v = kzalloc(n, skcipher_walk_gfp(walk));
if (!v)
return skcipher_walk_done(walk, -ENOMEM);
if (phys) {
p = v;
p->len = bsize;
skcipher_queue_write(walk, p);
buffer = p->buffer;
} else {
walk->buffer = v;
buffer = v;
}
ok:
walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
walk->src.virt.addr = walk->dst.virt.addr;
scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
walk->nbytes = bsize;
walk->flags |= SKCIPHER_WALK_SLOW;
return 0;
}
static int skcipher_next_copy(struct skcipher_walk *walk)
{
struct skcipher_walk_buffer *p;
u8 *tmp = walk->page;
skcipher_map_src(walk);
memcpy(tmp, walk->src.virt.addr, walk->nbytes);
skcipher_unmap_src(walk);
walk->src.virt.addr = tmp;
walk->dst.virt.addr = tmp;
if (!(walk->flags & SKCIPHER_WALK_PHYS))
return 0;
p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
if (!p)
return -ENOMEM;
p->data = walk->page;
p->len = walk->nbytes;
skcipher_queue_write(walk, p);
if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
PAGE_SIZE)
walk->page = NULL;
else
walk->page += walk->nbytes;
return 0;
}
static int skcipher_next_fast(struct skcipher_walk *walk)
{
unsigned long diff;
walk->src.phys.page = scatterwalk_page(&walk->in);
walk->src.phys.offset = offset_in_page(walk->in.offset);
walk->dst.phys.page = scatterwalk_page(&walk->out);
walk->dst.phys.offset = offset_in_page(walk->out.offset);
if (walk->flags & SKCIPHER_WALK_PHYS)
return 0;
diff = walk->src.phys.offset - walk->dst.phys.offset;
diff |= walk->src.virt.page - walk->dst.virt.page;
skcipher_map_src(walk);
walk->dst.virt.addr = walk->src.virt.addr;
if (diff) {
walk->flags |= SKCIPHER_WALK_DIFF;
skcipher_map_dst(walk);
}
return 0;
}
static int skcipher_walk_next(struct skcipher_walk *walk)
{
unsigned int bsize;
unsigned int n;
int err;
walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
SKCIPHER_WALK_DIFF);
n = walk->total;
bsize = min(walk->stride, max(n, walk->blocksize));
n = scatterwalk_clamp(&walk->in, n);
n = scatterwalk_clamp(&walk->out, n);
if (unlikely(n < bsize)) {
if (unlikely(walk->total < walk->blocksize))
return skcipher_walk_done(walk, -EINVAL);
slow_path:
err = skcipher_next_slow(walk, bsize);
goto set_phys_lowmem;
}
if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
if (!walk->page) {
gfp_t gfp = skcipher_walk_gfp(walk);
walk->page = (void *)__get_free_page(gfp);
if (!walk->page)
goto slow_path;
}
walk->nbytes = min_t(unsigned, n,
PAGE_SIZE - offset_in_page(walk->page));
walk->flags |= SKCIPHER_WALK_COPY;
err = skcipher_next_copy(walk);
goto set_phys_lowmem;
}
walk->nbytes = n;
return skcipher_next_fast(walk);
set_phys_lowmem:
if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) {
walk->src.phys.page = virt_to_page(walk->src.virt.addr);
walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
walk->src.phys.offset &= PAGE_SIZE - 1;
walk->dst.phys.offset &= PAGE_SIZE - 1;
}
return err;
}
static int skcipher_copy_iv(struct skcipher_walk *walk)
{
unsigned a = crypto_tfm_ctx_alignment() - 1;
unsigned alignmask = walk->alignmask;
unsigned ivsize = walk->ivsize;
unsigned bs = walk->stride;
unsigned aligned_bs;
unsigned size;
u8 *iv;
aligned_bs = ALIGN(bs, alignmask + 1);
/* Minimum size to align buffer by alignmask. */
size = alignmask & ~a;
if (walk->flags & SKCIPHER_WALK_PHYS)
size += ivsize;
else {
size += aligned_bs + ivsize;
/* Minimum size to ensure buffer does not straddle a page. */
size += (bs - 1) & ~(alignmask | a);
}
walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
if (!walk->buffer)
return -ENOMEM;
iv = PTR_ALIGN(walk->buffer, alignmask + 1);
iv = skcipher_get_spot(iv, bs) + aligned_bs;
walk->iv = memcpy(iv, walk->iv, walk->ivsize);
return 0;
}
static int skcipher_walk_first(struct skcipher_walk *walk)
{
if (WARN_ON_ONCE(in_irq()))
return -EDEADLK;
walk->buffer = NULL;
if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
int err = skcipher_copy_iv(walk);
if (err)
return err;
}
walk->page = NULL;
return skcipher_walk_next(walk);
}
static int skcipher_walk_skcipher(struct skcipher_walk *walk,
struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
walk->total = req->cryptlen;
walk->nbytes = 0;
walk->iv = req->iv;
walk->oiv = req->iv;
if (unlikely(!walk->total))
return 0;
scatterwalk_start(&walk->in, req->src);
scatterwalk_start(&walk->out, req->dst);
walk->flags &= ~SKCIPHER_WALK_SLEEP;
walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
SKCIPHER_WALK_SLEEP : 0;
walk->blocksize = crypto_skcipher_blocksize(tfm);
walk->stride = crypto_skcipher_walksize(tfm);
walk->ivsize = crypto_skcipher_ivsize(tfm);
walk->alignmask = crypto_skcipher_alignmask(tfm);
return skcipher_walk_first(walk);
}
int skcipher_walk_virt(struct skcipher_walk *walk,
struct skcipher_request *req, bool atomic)
{
int err;
might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
walk->flags &= ~SKCIPHER_WALK_PHYS;
err = skcipher_walk_skcipher(walk, req);
walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
return err;
}
EXPORT_SYMBOL_GPL(skcipher_walk_virt);
void skcipher_walk_atomise(struct skcipher_walk *walk)
{
walk->flags &= ~SKCIPHER_WALK_SLEEP;
}
EXPORT_SYMBOL_GPL(skcipher_walk_atomise);
int skcipher_walk_async(struct skcipher_walk *walk,
struct skcipher_request *req)
{
walk->flags |= SKCIPHER_WALK_PHYS;
INIT_LIST_HEAD(&walk->buffers);
return skcipher_walk_skcipher(walk, req);
}
EXPORT_SYMBOL_GPL(skcipher_walk_async);
static int skcipher_walk_aead_common(struct skcipher_walk *walk,
struct aead_request *req, bool atomic)
{
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
int err;
walk->nbytes = 0;
walk->iv = req->iv;
walk->oiv = req->iv;
if (unlikely(!walk->total))
return 0;
walk->flags &= ~SKCIPHER_WALK_PHYS;
scatterwalk_start(&walk->in, req->src);
scatterwalk_start(&walk->out, req->dst);
scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
scatterwalk_done(&walk->in, 0, walk->total);
scatterwalk_done(&walk->out, 0, walk->total);
if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
walk->flags |= SKCIPHER_WALK_SLEEP;
else
walk->flags &= ~SKCIPHER_WALK_SLEEP;
walk->blocksize = crypto_aead_blocksize(tfm);
walk->stride = crypto_aead_chunksize(tfm);
walk->ivsize = crypto_aead_ivsize(tfm);
walk->alignmask = crypto_aead_alignmask(tfm);
err = skcipher_walk_first(walk);
if (atomic)
walk->flags &= ~SKCIPHER_WALK_SLEEP;
return err;
}
int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
struct aead_request *req, bool atomic)
{
walk->total = req->cryptlen;
return skcipher_walk_aead_common(walk, req, atomic);
}
EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
struct aead_request *req, bool atomic)
{
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
walk->total = req->cryptlen - crypto_aead_authsize(tfm);
return skcipher_walk_aead_common(walk, req, atomic);
}
EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
static void skcipher_set_needkey(struct crypto_skcipher *tfm)
{
if (crypto_skcipher_max_keysize(tfm) != 0)
crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
}
static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
const u8 *key, unsigned int keylen)
{
unsigned long alignmask = crypto_skcipher_alignmask(tfm);
struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
u8 *buffer, *alignbuffer;
unsigned long absize;
int ret;
absize = keylen + alignmask;
buffer = kmalloc(absize, GFP_ATOMIC);
if (!buffer)
return -ENOMEM;
alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = cipher->setkey(tfm, alignbuffer, keylen);
kzfree(buffer);
return ret;
}
int crypto_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keylen)
{
struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
unsigned long alignmask = crypto_skcipher_alignmask(tfm);
int err;
if (keylen < cipher->min_keysize || keylen > cipher->max_keysize)
return -EINVAL;
if ((unsigned long)key & alignmask)
err = skcipher_setkey_unaligned(tfm, key, keylen);
else
err = cipher->setkey(tfm, key, keylen);
if (unlikely(err)) {
skcipher_set_needkey(tfm);
return err;
}
crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_skcipher_setkey);
int crypto_skcipher_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_alg *alg = tfm->base.__crt_alg;
unsigned int cryptlen = req->cryptlen;
int ret;
crypto_stats_get(alg);
if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
ret = -ENOKEY;
else
ret = crypto_skcipher_alg(tfm)->encrypt(req);
crypto_stats_skcipher_encrypt(cryptlen, ret, alg);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt);
int crypto_skcipher_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_alg *alg = tfm->base.__crt_alg;
unsigned int cryptlen = req->cryptlen;
int ret;
crypto_stats_get(alg);
if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
ret = -ENOKEY;
else
ret = crypto_skcipher_alg(tfm)->decrypt(req);
crypto_stats_skcipher_decrypt(cryptlen, ret, alg);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt);
static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
alg->exit(skcipher);
}
static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
skcipher_set_needkey(skcipher);
if (alg->exit)
skcipher->base.exit = crypto_skcipher_exit_tfm;
if (alg->init)
return alg->init(skcipher);
return 0;
}
static void crypto_skcipher_free_instance(struct crypto_instance *inst)
{
struct skcipher_instance *skcipher =
container_of(inst, struct skcipher_instance, s.base);
skcipher->free(skcipher);
}
static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
__maybe_unused;
static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
base);
seq_printf(m, "type : skcipher\n");
seq_printf(m, "async : %s\n",
alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no");
seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
seq_printf(m, "min keysize : %u\n", skcipher->min_keysize);
seq_printf(m, "max keysize : %u\n", skcipher->max_keysize);
seq_printf(m, "ivsize : %u\n", skcipher->ivsize);
seq_printf(m, "chunksize : %u\n", skcipher->chunksize);
seq_printf(m, "walksize : %u\n", skcipher->walksize);
}
#ifdef CONFIG_NET
static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_blkcipher rblkcipher;
struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
base);
memset(&rblkcipher, 0, sizeof(rblkcipher));
strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
rblkcipher.blocksize = alg->cra_blocksize;
rblkcipher.min_keysize = skcipher->min_keysize;
rblkcipher.max_keysize = skcipher->max_keysize;
rblkcipher.ivsize = skcipher->ivsize;
return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
sizeof(rblkcipher), &rblkcipher);
}
#else
static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
return -ENOSYS;
}
#endif
static const struct crypto_type crypto_skcipher_type = {
.extsize = crypto_alg_extsize,
.init_tfm = crypto_skcipher_init_tfm,
.free = crypto_skcipher_free_instance,
#ifdef CONFIG_PROC_FS
.show = crypto_skcipher_show,
#endif
.report = crypto_skcipher_report,
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_MASK,
.type = CRYPTO_ALG_TYPE_SKCIPHER,
.tfmsize = offsetof(struct crypto_skcipher, base),
};
int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
struct crypto_instance *inst,
const char *name, u32 type, u32 mask)
{
spawn->base.frontend = &crypto_skcipher_type;
return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
u32 type, u32 mask)
{
return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
const char *alg_name, u32 type, u32 mask)
{
struct crypto_skcipher *tfm;
/* Only sync algorithms allowed. */
mask |= CRYPTO_ALG_ASYNC;
tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
/*
* Make sure we do not allocate something that might get used with
* an on-stack request: check the request size.
*/
if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
MAX_SYNC_SKCIPHER_REQSIZE)) {
crypto_free_skcipher(tfm);
return ERR_PTR(-EINVAL);
}
return (struct crypto_sync_skcipher *)tfm;
}
EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);
int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask)
{
return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_has_skcipher);
static int skcipher_prepare_alg(struct skcipher_alg *alg)
{
struct crypto_alg *base = &alg->base;
if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
alg->walksize > PAGE_SIZE / 8)
return -EINVAL;
if (!alg->chunksize)
alg->chunksize = base->cra_blocksize;
if (!alg->walksize)
alg->walksize = alg->chunksize;
base->cra_type = &crypto_skcipher_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
return 0;
}
int crypto_register_skcipher(struct skcipher_alg *alg)
{
struct crypto_alg *base = &alg->base;
int err;
err = skcipher_prepare_alg(alg);
if (err)
return err;
return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_skcipher);
void crypto_unregister_skcipher(struct skcipher_alg *alg)
{
crypto_unregister_alg(&alg->base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
int crypto_register_skciphers(struct skcipher_alg *algs, int count)
{
int i, ret;
for (i = 0; i < count; i++) {
ret = crypto_register_skcipher(&algs[i]);
if (ret)
goto err;
}
return 0;
err:
for (--i; i >= 0; --i)
crypto_unregister_skcipher(&algs[i]);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_skciphers);
void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
{
int i;
for (i = count - 1; i >= 0; --i)
crypto_unregister_skcipher(&algs[i]);
}
EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
int skcipher_register_instance(struct crypto_template *tmpl,
struct skcipher_instance *inst)
{
int err;
if (WARN_ON(!inst->free))
return -EINVAL;
err = skcipher_prepare_alg(&inst->alg);
if (err)
return err;
return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
}
EXPORT_SYMBOL_GPL(skcipher_register_instance);
static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keylen)
{
struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) &
CRYPTO_TFM_REQ_MASK);
return crypto_cipher_setkey(cipher, key, keylen);
}
static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
{
struct skcipher_instance *inst = skcipher_alg_instance(tfm);
struct crypto_cipher_spawn *spawn = skcipher_instance_ctx(inst);
struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
struct crypto_cipher *cipher;
cipher = crypto_spawn_cipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
ctx->cipher = cipher;
return 0;
}
static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm)
{
struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
crypto_free_cipher(ctx->cipher);
}
static void skcipher_free_instance_simple(struct skcipher_instance *inst)
{
crypto_drop_cipher(skcipher_instance_ctx(inst));
kfree(inst);
}
/**
* skcipher_alloc_instance_simple - allocate instance of simple block cipher mode
*
* Allocate an skcipher_instance for a simple block cipher mode of operation,
* e.g. cbc or ecb. The instance context will have just a single crypto_spawn,
* that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize,
* alignmask, and priority are set from the underlying cipher but can be
* overridden if needed. The tfm context defaults to skcipher_ctx_simple, and
* default ->setkey(), ->init(), and ->exit() methods are installed.
*
* @tmpl: the template being instantiated
* @tb: the template parameters
*
* Return: a pointer to the new instance, or an ERR_PTR(). The caller still
* needs to register the instance.
*/
struct skcipher_instance *skcipher_alloc_instance_simple(
struct crypto_template *tmpl, struct rtattr **tb)
{
struct crypto_attr_type *algt;
u32 mask;
struct skcipher_instance *inst;
struct crypto_cipher_spawn *spawn;
struct crypto_alg *cipher_alg;
int err;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return ERR_CAST(algt);
if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
return ERR_PTR(-EINVAL);
mask = crypto_requires_off(algt->type, algt->mask,
CRYPTO_ALG_NEED_FALLBACK);
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return ERR_PTR(-ENOMEM);
spawn = skcipher_instance_ctx(inst);
err = crypto_grab_cipher(spawn, skcipher_crypto_instance(inst),
crypto_attr_alg_name(tb[1]), 0, mask);
if (err)
goto err_free_inst;
cipher_alg = crypto_spawn_cipher_alg(spawn);
err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name,
cipher_alg);
if (err)
goto err_free_inst;
inst->free = skcipher_free_instance_simple;
/* Default algorithm properties, can be overridden */
inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize;
inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask;
inst->alg.base.cra_priority = cipher_alg->cra_priority;
inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
inst->alg.ivsize = cipher_alg->cra_blocksize;
/* Use skcipher_ctx_simple by default, can be overridden */
inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple);
inst->alg.setkey = skcipher_setkey_simple;
inst->alg.init = skcipher_init_tfm_simple;
inst->alg.exit = skcipher_exit_tfm_simple;
return inst;
err_free_inst:
skcipher_free_instance_simple(inst);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Symmetric key cipher type");
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