linux/crypto/ablkcipher.c

413 lines
11 KiB
C

/*
* 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/err.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/cryptouser.h>
#include <linux/compiler.h>
#include <net/netlink.h>
#include <crypto/scatterwalk.h>
#include "internal.h"
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 void ablkcipher_done_slow(struct ablkcipher_walk *walk,
unsigned int n)
{
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, sg_next(walk->out.sg));
}
}
static inline void ablkcipher_done_fast(struct ablkcipher_walk *walk,
unsigned int n)
{
scatterwalk_advance(&walk->in, n);
scatterwalk_advance(&walk->out, 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 n; /* bytes processed */
bool more;
if (unlikely(err < 0))
goto finish;
n = walk->nbytes - err;
walk->total -= n;
more = (walk->total != 0);
if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW))) {
ablkcipher_done_fast(walk, n);
} else {
if (WARN_ON(err)) {
/* unexpected case; didn't process all bytes */
err = -EINVAL;
goto finish;
}
ablkcipher_done_slow(walk, n);
}
scatterwalk_done(&walk->in, 0, more);
scatterwalk_done(&walk->out, 1, more);
if (more) {
crypto_yield(req->base.flags);
return ablkcipher_walk_next(req, walk);
}
err = 0;
finish:
walk->nbytes = 0;
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->iv = req->info;
walk->nbytes = walk->total;
if (unlikely(!walk->total))
return 0;
walk->iv_buffer = NULL;
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;
}
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;
crt->base = __crypto_ablkcipher_cast(tfm);
crt->ivsize = alg->ivsize;
return 0;
}
#ifdef CONFIG_NET
static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_blkcipher rblkcipher;
memset(&rblkcipher, 0, sizeof(rblkcipher));
strscpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
strscpy(rblkcipher.geniv, "<default>", sizeof(rblkcipher.geniv));
rblkcipher.blocksize = alg->cra_blocksize;
rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
sizeof(rblkcipher), &rblkcipher);
}
#else
static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
return -ENOSYS;
}
#endif
static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
__maybe_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 : <default>\n");
}
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
.report = crypto_ablkcipher_report,
};
EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);