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/*
* Asynchronous block chaining cipher operations.
*
* This is the asynchronous version of blkcipher.c indicating completion
* via a callback.
*
* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <crypto/internal/skcipher.h>
#include <linux/cpumask.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <crypto/scatterwalk.h>
#include "internal.h"
static const char *skcipher_default_geniv __read_mostly;
struct ablkcipher_buffer {
struct list_head entry;
struct scatter_walk dst;
unsigned int len;
void *data;
};
enum {
ABLKCIPHER_WALK_SLOW = 1 << 0,
};
static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
{
scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
}
void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
{
struct ablkcipher_buffer *p, *tmp;
list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
ablkcipher_buffer_write(p);
list_del(&p->entry);
kfree(p);
}
}
EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
struct ablkcipher_buffer *p)
{
p->dst = walk->out;
list_add_tail(&p->entry, &walk->buffers);
}
/* 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 *ablkcipher_get_spot(u8 *start, unsigned int len)
{
u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
return max(start, end_page);
}
static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
unsigned int bsize)
{
unsigned int n = bsize;
for (;;) {
unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
if (len_this_page > n)
len_this_page = n;
scatterwalk_advance(&walk->out, n);
if (n == len_this_page)
break;
n -= len_this_page;
scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
}
return bsize;
}
static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
unsigned int n)
{
scatterwalk_advance(&walk->in, n);
scatterwalk_advance(&walk->out, n);
return n;
}
static int ablkcipher_walk_next(struct ablkcipher_request *req,
struct ablkcipher_walk *walk);
int ablkcipher_walk_done(struct ablkcipher_request *req,
struct ablkcipher_walk *walk, int err)
{
struct crypto_tfm *tfm = req->base.tfm;
unsigned int nbytes = 0;
if (likely(err >= 0)) {
unsigned int n = walk->nbytes - err;
if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
n = ablkcipher_done_fast(walk, n);
else if (WARN_ON(err)) {
err = -EINVAL;
goto err;
} else
n = ablkcipher_done_slow(walk, n);
nbytes = walk->total - n;
err = 0;
}
scatterwalk_done(&walk->in, 0, nbytes);
scatterwalk_done(&walk->out, 1, nbytes);
err:
walk->total = nbytes;
walk->nbytes = nbytes;
if (nbytes) {
crypto_yield(req->base.flags);
return ablkcipher_walk_next(req, walk);
}
if (walk->iv != req->info)
memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
kfree(walk->iv_buffer);
return err;
}
EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
struct ablkcipher_walk *walk,
unsigned int bsize,
unsigned int alignmask,
void **src_p, void **dst_p)
{
unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
struct ablkcipher_buffer *p;
void *src, *dst, *base;
unsigned int n;
n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
n += (aligned_bsize * 3 - (alignmask + 1) +
(alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
p = kmalloc(n, GFP_ATOMIC);
if (!p)
return ablkcipher_walk_done(req, walk, -ENOMEM);
base = p + 1;
dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
src = dst = ablkcipher_get_spot(dst, bsize);
p->len = bsize;
p->data = dst;
scatterwalk_copychunks(src, &walk->in, bsize, 0);
ablkcipher_queue_write(walk, p);
walk->nbytes = bsize;
walk->flags |= ABLKCIPHER_WALK_SLOW;
*src_p = src;
*dst_p = dst;
return 0;
}
static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
struct crypto_tfm *tfm,
unsigned int alignmask)
{
unsigned bs = walk->blocksize;
unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
unsigned aligned_bs = ALIGN(bs, alignmask + 1);
unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
(alignmask + 1);
u8 *iv;
size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
if (!walk->iv_buffer)
return -ENOMEM;
iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
iv = ablkcipher_get_spot(iv, ivsize);
walk->iv = memcpy(iv, walk->iv, ivsize);
return 0;
}
static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
struct ablkcipher_walk *walk)
{
walk->src.page = scatterwalk_page(&walk->in);
walk->src.offset = offset_in_page(walk->in.offset);
walk->dst.page = scatterwalk_page(&walk->out);
walk->dst.offset = offset_in_page(walk->out.offset);
return 0;
}
static int ablkcipher_walk_next(struct ablkcipher_request *req,
struct ablkcipher_walk *walk)
{
struct crypto_tfm *tfm = req->base.tfm;
unsigned int alignmask, bsize, n;
void *src, *dst;
int err;
alignmask = crypto_tfm_alg_alignmask(tfm);
n = walk->total;
if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
return ablkcipher_walk_done(req, walk, -EINVAL);
}
walk->flags &= ~ABLKCIPHER_WALK_SLOW;
src = dst = NULL;
bsize = min(walk->blocksize, n);
n = scatterwalk_clamp(&walk->in, n);
n = scatterwalk_clamp(&walk->out, n);
if (n < bsize ||
!scatterwalk_aligned(&walk->in, alignmask) ||
!scatterwalk_aligned(&walk->out, alignmask)) {
err = ablkcipher_next_slow(req, walk, bsize, alignmask,
&src, &dst);
goto set_phys_lowmem;
}
walk->nbytes = n;
return ablkcipher_next_fast(req, walk);
set_phys_lowmem:
if (err >= 0) {
walk->src.page = virt_to_page(src);
walk->dst.page = virt_to_page(dst);
walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
}
return err;
}
static int ablkcipher_walk_first(struct ablkcipher_request *req,
struct ablkcipher_walk *walk)
{
struct crypto_tfm *tfm = req->base.tfm;
unsigned int alignmask;
alignmask = crypto_tfm_alg_alignmask(tfm);
if (WARN_ON_ONCE(in_irq()))
return -EDEADLK;
walk->nbytes = walk->total;
if (unlikely(!walk->total))
return 0;
walk->iv_buffer = NULL;
walk->iv = req->info;
if (unlikely(((unsigned long)walk->iv & alignmask))) {
int err = ablkcipher_copy_iv(walk, tfm, alignmask);
if (err)
return err;
}
scatterwalk_start(&walk->in, walk->in.sg);
scatterwalk_start(&walk->out, walk->out.sg);
return ablkcipher_walk_next(req, walk);
}
int ablkcipher_walk_phys(struct ablkcipher_request *req,
struct ablkcipher_walk *walk)
{
walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
return ablkcipher_walk_first(req, walk);
}
EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
unsigned int keylen)
{
struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
int ret;
u8 *buffer, *alignbuffer;
unsigned long absize;
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);
memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
unsigned int keylen)
{
struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
if ((unsigned long)key & alignmask)
return setkey_unaligned(tfm, key, keylen);
return cipher->setkey(tfm, key, keylen);
}
static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
u32 mask)
{
return alg->cra_ctxsize;
}
int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
{
return crypto_ablkcipher_encrypt(&req->creq);
}
int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
{
return crypto_ablkcipher_decrypt(&req->creq);
}
static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
u32 mask)
{
struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
if (alg->ivsize > PAGE_SIZE / 8)
return -EINVAL;
crt->setkey = setkey;
crt->encrypt = alg->encrypt;
crt->decrypt = alg->decrypt;
if (!alg->ivsize) {
crt->givencrypt = skcipher_null_givencrypt;
crt->givdecrypt = skcipher_null_givdecrypt;
}
crt->base = __crypto_ablkcipher_cast(tfm);
crt->ivsize = alg->ivsize;
return 0;
}
static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
seq_printf(m, "type : ablkcipher\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", ablkcipher->min_keysize);
seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<default>");
}
const struct crypto_type crypto_ablkcipher_type = {
.ctxsize = crypto_ablkcipher_ctxsize,
.init = crypto_init_ablkcipher_ops,
#ifdef CONFIG_PROC_FS
.show = crypto_ablkcipher_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
static int no_givdecrypt(struct skcipher_givcrypt_request *req)
{
return -ENOSYS;
}
static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
u32 mask)
{
struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
if (alg->ivsize > PAGE_SIZE / 8)
return -EINVAL;
crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
alg->setkey : setkey;
crt->encrypt = alg->encrypt;
crt->decrypt = alg->decrypt;
crt->givencrypt = alg->givencrypt;
crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
crt->base = __crypto_ablkcipher_cast(tfm);
crt->ivsize = alg->ivsize;
return 0;
}
static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
seq_printf(m, "type : givcipher\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", ablkcipher->min_keysize);
seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<built-in>");
}
const struct crypto_type crypto_givcipher_type = {
.ctxsize = crypto_ablkcipher_ctxsize,
.init = crypto_init_givcipher_ops,
#ifdef CONFIG_PROC_FS
.show = crypto_givcipher_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_givcipher_type);
const char *crypto_default_geniv(const struct crypto_alg *alg)
{
if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
alg->cra_ablkcipher.ivsize) !=
alg->cra_blocksize)
return "chainiv";
return alg->cra_flags & CRYPTO_ALG_ASYNC ?
"eseqiv" : skcipher_default_geniv;
}
static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
{
struct rtattr *tb[3];
struct {
struct rtattr attr;
struct crypto_attr_type data;
} ptype;
struct {
struct rtattr attr;
struct crypto_attr_alg data;
} palg;
struct crypto_template *tmpl;
struct crypto_instance *inst;
struct crypto_alg *larval;
const char *geniv;
int err;
larval = crypto_larval_lookup(alg->cra_driver_name,
(type & ~CRYPTO_ALG_TYPE_MASK) |
CRYPTO_ALG_TYPE_GIVCIPHER,
mask | CRYPTO_ALG_TYPE_MASK);
err = PTR_ERR(larval);
if (IS_ERR(larval))
goto out;
err = -EAGAIN;
if (!crypto_is_larval(larval))
goto drop_larval;
ptype.attr.rta_len = sizeof(ptype);
ptype.attr.rta_type = CRYPTOA_TYPE;
ptype.data.type = type | CRYPTO_ALG_GENIV;
/* GENIV tells the template that we're making a default geniv. */
ptype.data.mask = mask | CRYPTO_ALG_GENIV;
tb[0] = &ptype.attr;
palg.attr.rta_len = sizeof(palg);
palg.attr.rta_type = CRYPTOA_ALG;
/* Must use the exact name to locate ourselves. */
memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
tb[1] = &palg.attr;
tb[2] = NULL;
if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER)
geniv = alg->cra_blkcipher.geniv;
else
geniv = alg->cra_ablkcipher.geniv;
if (!geniv)
geniv = crypto_default_geniv(alg);
tmpl = crypto_lookup_template(geniv);
err = -ENOENT;
if (!tmpl)
goto kill_larval;
inst = tmpl->alloc(tb);
err = PTR_ERR(inst);
if (IS_ERR(inst))
goto put_tmpl;
if ((err = crypto_register_instance(tmpl, inst))) {
tmpl->free(inst);
goto put_tmpl;
}
/* Redo the lookup to use the instance we just registered. */
err = -EAGAIN;
put_tmpl:
crypto_tmpl_put(tmpl);
kill_larval:
crypto_larval_kill(larval);
drop_larval:
crypto_mod_put(larval);
out:
crypto_mod_put(alg);
return err;
}
static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
u32 mask)
{
struct crypto_alg *alg;
alg = crypto_alg_mod_lookup(name, type, mask);
if (IS_ERR(alg))
return alg;
if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_GIVCIPHER)
return alg;
if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
alg->cra_ablkcipher.ivsize))
return alg;
crypto_mod_put(alg);
alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
mask & ~CRYPTO_ALG_TESTED);
if (IS_ERR(alg))
return alg;
if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_GIVCIPHER) {
if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
crypto_mod_put(alg);
alg = ERR_PTR(-ENOENT);
}
return alg;
}
BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
alg->cra_ablkcipher.ivsize));
return ERR_PTR(crypto_givcipher_default(alg, type, mask));
}
int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
u32 type, u32 mask)
{
struct crypto_alg *alg;
int err;
type = crypto_skcipher_type(type);
mask = crypto_skcipher_mask(mask);
alg = crypto_lookup_skcipher(name, type, mask);
if (IS_ERR(alg))
return PTR_ERR(alg);
err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
crypto_mod_put(alg);
return err;
}
EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
u32 type, u32 mask)
{
struct crypto_tfm *tfm;
int err;
type = crypto_skcipher_type(type);
mask = crypto_skcipher_mask(mask);
for (;;) {
struct crypto_alg *alg;
alg = crypto_lookup_skcipher(alg_name, type, mask);
if (IS_ERR(alg)) {
err = PTR_ERR(alg);
goto err;
}
tfm = __crypto_alloc_tfm(alg, type, mask);
if (!IS_ERR(tfm))
return __crypto_ablkcipher_cast(tfm);
crypto_mod_put(alg);
err = PTR_ERR(tfm);
err:
if (err != -EAGAIN)
break;
if (signal_pending(current)) {
err = -EINTR;
break;
}
}
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
static int __init skcipher_module_init(void)
{
skcipher_default_geniv = num_possible_cpus() > 1 ?
"eseqiv" : "chainiv";
return 0;
}
static void skcipher_module_exit(void)
{
}
module_init(skcipher_module_init);
module_exit(skcipher_module_exit);
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