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linux-next/crypto/ahash.c
Marek Vasut d4a7a0fbe9 crypto: hash - Simplify the ahash_finup implementation
The ahash_def_finup() can make use of the request save/restore functions,
thus make it so. This simplifies the code a little and unifies the code
paths.

Note that the same remark about free()ing the req->priv applies here, the
req->priv can only be free()'d after the original request was restored.

Finally, squash a bug in the invocation of completion in the ASYNC path.
In both ahash_def_finup_done{1,2}, the function areq->base.complete(X, err);
was called with X=areq->base.data . This is incorrect , as X=&areq->base
is the correct value. By analysis of the data structures, we see the areq is
of type 'struct ahash_request' , areq->base is of type 'struct crypto_async_request'
and areq->base.completion is of type crypto_completion_t, which is defined in
include/linux/crypto.h as:

  typedef void (*crypto_completion_t)(struct crypto_async_request *req, int err);

This is one lead that the X should be &areq->base . Next up, we can inspect
other code which calls the completion callback to give us kind-of statistical
idea of how this callback is used. We can try:

  $ git grep base\.complete\( drivers/crypto/

Finally, by inspecting ahash_request_set_callback() implementation defined
in include/crypto/hash.h , we observe that the .data entry of 'struct
crypto_async_request' is intended for arbitrary data, not for completion
argument.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-03-21 21:54:22 +08:00

578 lines
14 KiB
C

/*
* Asynchronous Cryptographic Hash operations.
*
* This is the asynchronous version of hash.c with notification of
* completion via a callback.
*
* Copyright (c) 2008 Loc Ho <lho@amcc.com>
*
* 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/hash.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>
#include "internal.h"
struct ahash_request_priv {
crypto_completion_t complete;
void *data;
u8 *result;
void *ubuf[] CRYPTO_MINALIGN_ATTR;
};
static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
{
return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
halg);
}
static int hash_walk_next(struct crypto_hash_walk *walk)
{
unsigned int alignmask = walk->alignmask;
unsigned int offset = walk->offset;
unsigned int nbytes = min(walk->entrylen,
((unsigned int)(PAGE_SIZE)) - offset);
walk->data = kmap_atomic(walk->pg);
walk->data += offset;
if (offset & alignmask) {
unsigned int unaligned = alignmask + 1 - (offset & alignmask);
if (nbytes > unaligned)
nbytes = unaligned;
}
walk->entrylen -= nbytes;
return nbytes;
}
static int hash_walk_new_entry(struct crypto_hash_walk *walk)
{
struct scatterlist *sg;
sg = walk->sg;
walk->pg = sg_page(sg);
walk->offset = sg->offset;
walk->entrylen = sg->length;
if (walk->entrylen > walk->total)
walk->entrylen = walk->total;
walk->total -= walk->entrylen;
return hash_walk_next(walk);
}
int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
{
unsigned int alignmask = walk->alignmask;
unsigned int nbytes = walk->entrylen;
walk->data -= walk->offset;
if (nbytes && walk->offset & alignmask && !err) {
walk->offset = ALIGN(walk->offset, alignmask + 1);
walk->data += walk->offset;
nbytes = min(nbytes,
((unsigned int)(PAGE_SIZE)) - walk->offset);
walk->entrylen -= nbytes;
return nbytes;
}
kunmap_atomic(walk->data);
crypto_yield(walk->flags);
if (err)
return err;
if (nbytes) {
walk->offset = 0;
walk->pg++;
return hash_walk_next(walk);
}
if (!walk->total)
return 0;
walk->sg = scatterwalk_sg_next(walk->sg);
return hash_walk_new_entry(walk);
}
EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
int crypto_hash_walk_first(struct ahash_request *req,
struct crypto_hash_walk *walk)
{
walk->total = req->nbytes;
if (!walk->total)
return 0;
walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
walk->sg = req->src;
walk->flags = req->base.flags;
return hash_walk_new_entry(walk);
}
EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
struct crypto_hash_walk *walk,
struct scatterlist *sg, unsigned int len)
{
walk->total = len;
if (!walk->total)
return 0;
walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
walk->sg = sg;
walk->flags = hdesc->flags;
return hash_walk_new_entry(walk);
}
static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen)
{
unsigned long alignmask = crypto_ahash_alignmask(tfm);
int ret;
u8 *buffer, *alignbuffer;
unsigned long absize;
absize = keylen + alignmask;
buffer = kmalloc(absize, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = tfm->setkey(tfm, alignbuffer, keylen);
kzfree(buffer);
return ret;
}
int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen)
{
unsigned long alignmask = crypto_ahash_alignmask(tfm);
if ((unsigned long)key & alignmask)
return ahash_setkey_unaligned(tfm, key, keylen);
return tfm->setkey(tfm, key, keylen);
}
EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen)
{
return -ENOSYS;
}
static inline unsigned int ahash_align_buffer_size(unsigned len,
unsigned long mask)
{
return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
}
static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
unsigned long alignmask = crypto_ahash_alignmask(tfm);
unsigned int ds = crypto_ahash_digestsize(tfm);
struct ahash_request_priv *priv;
priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC);
if (!priv)
return -ENOMEM;
/*
* WARNING: Voodoo programming below!
*
* The code below is obscure and hard to understand, thus explanation
* is necessary. See include/crypto/hash.h and include/linux/crypto.h
* to understand the layout of structures used here!
*
* The code here will replace portions of the ORIGINAL request with
* pointers to new code and buffers so the hashing operation can store
* the result in aligned buffer. We will call the modified request
* an ADJUSTED request.
*
* The newly mangled request will look as such:
*
* req {
* .result = ADJUSTED[new aligned buffer]
* .base.complete = ADJUSTED[pointer to completion function]
* .base.data = ADJUSTED[*req (pointer to self)]
* .priv = ADJUSTED[new priv] {
* .result = ORIGINAL(result)
* .complete = ORIGINAL(base.complete)
* .data = ORIGINAL(base.data)
* }
*/
priv->result = req->result;
priv->complete = req->base.complete;
priv->data = req->base.data;
/*
* WARNING: We do not backup req->priv here! The req->priv
* is for internal use of the Crypto API and the
* user must _NOT_ _EVER_ depend on it's content!
*/
req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
req->base.complete = cplt;
req->base.data = req;
req->priv = priv;
return 0;
}
static void ahash_restore_req(struct ahash_request *req)
{
struct ahash_request_priv *priv = req->priv;
/* Restore the original crypto request. */
req->result = priv->result;
req->base.complete = priv->complete;
req->base.data = priv->data;
req->priv = NULL;
/* Free the req->priv.priv from the ADJUSTED request. */
kzfree(priv);
}
static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
{
struct ahash_request_priv *priv = req->priv;
if (err == -EINPROGRESS)
return;
if (!err)
memcpy(priv->result, req->result,
crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
ahash_restore_req(req);
}
static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
{
struct ahash_request *areq = req->data;
/*
* Restore the original request, see ahash_op_unaligned() for what
* goes where.
*
* The "struct ahash_request *req" here is in fact the "req.base"
* from the ADJUSTED request from ahash_op_unaligned(), thus as it
* is a pointer to self, it is also the ADJUSTED "req" .
*/
/* First copy req->result into req->priv.result */
ahash_op_unaligned_finish(areq, err);
/* Complete the ORIGINAL request. */
areq->base.complete(&areq->base, err);
}
static int ahash_op_unaligned(struct ahash_request *req,
int (*op)(struct ahash_request *))
{
int err;
err = ahash_save_req(req, ahash_op_unaligned_done);
if (err)
return err;
err = op(req);
ahash_op_unaligned_finish(req, err);
return err;
}
static int crypto_ahash_op(struct ahash_request *req,
int (*op)(struct ahash_request *))
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
unsigned long alignmask = crypto_ahash_alignmask(tfm);
if ((unsigned long)req->result & alignmask)
return ahash_op_unaligned(req, op);
return op(req);
}
int crypto_ahash_final(struct ahash_request *req)
{
return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
}
EXPORT_SYMBOL_GPL(crypto_ahash_final);
int crypto_ahash_finup(struct ahash_request *req)
{
return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
}
EXPORT_SYMBOL_GPL(crypto_ahash_finup);
int crypto_ahash_digest(struct ahash_request *req)
{
return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
}
EXPORT_SYMBOL_GPL(crypto_ahash_digest);
static void ahash_def_finup_finish2(struct ahash_request *req, int err)
{
struct ahash_request_priv *priv = req->priv;
if (err == -EINPROGRESS)
return;
if (!err)
memcpy(priv->result, req->result,
crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
ahash_restore_req(req);
}
static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
{
struct ahash_request *areq = req->data;
ahash_def_finup_finish2(areq, err);
areq->base.complete(&areq->base, err);
}
static int ahash_def_finup_finish1(struct ahash_request *req, int err)
{
if (err)
goto out;
req->base.complete = ahash_def_finup_done2;
req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
err = crypto_ahash_reqtfm(req)->final(req);
out:
ahash_def_finup_finish2(req, err);
return err;
}
static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
{
struct ahash_request *areq = req->data;
err = ahash_def_finup_finish1(areq, err);
areq->base.complete(&areq->base, err);
}
static int ahash_def_finup(struct ahash_request *req)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
int err;
err = ahash_save_req(req, ahash_def_finup_done1);
if (err)
return err;
err = tfm->update(req);
return ahash_def_finup_finish1(req, err);
}
static int ahash_no_export(struct ahash_request *req, void *out)
{
return -ENOSYS;
}
static int ahash_no_import(struct ahash_request *req, const void *in)
{
return -ENOSYS;
}
static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
struct ahash_alg *alg = crypto_ahash_alg(hash);
hash->setkey = ahash_nosetkey;
hash->export = ahash_no_export;
hash->import = ahash_no_import;
if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
return crypto_init_shash_ops_async(tfm);
hash->init = alg->init;
hash->update = alg->update;
hash->final = alg->final;
hash->finup = alg->finup ?: ahash_def_finup;
hash->digest = alg->digest;
if (alg->setkey)
hash->setkey = alg->setkey;
if (alg->export)
hash->export = alg->export;
if (alg->import)
hash->import = alg->import;
return 0;
}
static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
{
if (alg->cra_type == &crypto_ahash_type)
return alg->cra_ctxsize;
return sizeof(struct crypto_shash *);
}
#ifdef CONFIG_NET
static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_hash rhash;
strncpy(rhash.type, "ahash", sizeof(rhash.type));
rhash.blocksize = alg->cra_blocksize;
rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
sizeof(struct crypto_report_hash), &rhash))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
#else
static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
{
return -ENOSYS;
}
#endif
static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
{
seq_printf(m, "type : ahash\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, "digestsize : %u\n",
__crypto_hash_alg_common(alg)->digestsize);
}
const struct crypto_type crypto_ahash_type = {
.extsize = crypto_ahash_extsize,
.init_tfm = crypto_ahash_init_tfm,
#ifdef CONFIG_PROC_FS
.show = crypto_ahash_show,
#endif
.report = crypto_ahash_report,
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
.type = CRYPTO_ALG_TYPE_AHASH,
.tfmsize = offsetof(struct crypto_ahash, base),
};
EXPORT_SYMBOL_GPL(crypto_ahash_type);
struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
u32 mask)
{
return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
static int ahash_prepare_alg(struct ahash_alg *alg)
{
struct crypto_alg *base = &alg->halg.base;
if (alg->halg.digestsize > PAGE_SIZE / 8 ||
alg->halg.statesize > PAGE_SIZE / 8)
return -EINVAL;
base->cra_type = &crypto_ahash_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
return 0;
}
int crypto_register_ahash(struct ahash_alg *alg)
{
struct crypto_alg *base = &alg->halg.base;
int err;
err = ahash_prepare_alg(alg);
if (err)
return err;
return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_ahash);
int crypto_unregister_ahash(struct ahash_alg *alg)
{
return crypto_unregister_alg(&alg->halg.base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
int ahash_register_instance(struct crypto_template *tmpl,
struct ahash_instance *inst)
{
int err;
err = ahash_prepare_alg(&inst->alg);
if (err)
return err;
return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
}
EXPORT_SYMBOL_GPL(ahash_register_instance);
void ahash_free_instance(struct crypto_instance *inst)
{
crypto_drop_spawn(crypto_instance_ctx(inst));
kfree(ahash_instance(inst));
}
EXPORT_SYMBOL_GPL(ahash_free_instance);
int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
struct hash_alg_common *alg,
struct crypto_instance *inst)
{
return crypto_init_spawn2(&spawn->base, &alg->base, inst,
&crypto_ahash_type);
}
EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
{
struct crypto_alg *alg;
alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
}
EXPORT_SYMBOL_GPL(ahash_attr_alg);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Asynchronous cryptographic hash type");