kernel-ark/crypto/ahash.c
Herbert Xu d315a0e09f crypto: hash - Fix handling of sg entry that crosses page boundary
A quirk that we've always supported is having an sg entry that's
bigger than a page, or more generally an sg entry that crosses
page boundaries.  Even though it would be better to explicitly have
to sg entries for this, we need to support it for the existing users,
in particular, IPsec.

The new ahash sg walking code did try to handle this, but there was
a bug where we didn't increment the page so kept on walking on the
first page over an dover again.

This patch fixes it.

Tested-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-05-31 23:09:22 +10:00

232 lines
5.5 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 "internal.h"
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 = crypto_kmap(walk->pg, 0);
walk->data += offset;
if (offset & alignmask)
nbytes = alignmask + 1 - (offset & alignmask);
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 += alignmask - 1;
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;
}
crypto_kunmap(walk->data, 0);
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)
{
struct ahash_alg *ahash = crypto_ahash_alg(tfm);
unsigned long alignmask = crypto_ahash_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 = ahash->setkey(tfm, alignbuffer, keylen);
memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen)
{
struct ahash_alg *ahash = crypto_ahash_alg(tfm);
unsigned long alignmask = crypto_ahash_alignmask(tfm);
if ((unsigned long)key & alignmask)
return ahash_setkey_unaligned(tfm, key, keylen);
return ahash->setkey(tfm, key, keylen);
}
static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen)
{
return -ENOSYS;
}
int crypto_ahash_import(struct ahash_request *req, const u8 *in)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ahash_alg *alg = crypto_ahash_alg(tfm);
memcpy(ahash_request_ctx(req), in, crypto_ahash_reqsize(tfm));
if (alg->reinit)
alg->reinit(req);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_ahash_import);
static unsigned int crypto_ahash_ctxsize(struct crypto_alg *alg, u32 type,
u32 mask)
{
return alg->cra_ctxsize;
}
static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
struct ahash_alg *alg = &tfm->__crt_alg->cra_ahash;
struct ahash_tfm *crt = &tfm->crt_ahash;
if (alg->digestsize > PAGE_SIZE / 8)
return -EINVAL;
crt->init = alg->init;
crt->update = alg->update;
crt->final = alg->final;
crt->digest = alg->digest;
crt->setkey = alg->setkey ? ahash_setkey : ahash_nosetkey;
crt->digestsize = alg->digestsize;
return 0;
}
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", alg->cra_ahash.digestsize);
}
const struct crypto_type crypto_ahash_type = {
.ctxsize = crypto_ahash_ctxsize,
.init = crypto_init_ahash_ops,
#ifdef CONFIG_PROC_FS
.show = crypto_ahash_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_ahash_type);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Asynchronous cryptographic hash type");