android_kernel_xiaomi_sm8350/crypto/ahash.c
Herbert Xu 20036252fc crypto: hash - Added scatter list walking helper
This patch adds the walking helpers for hash algorithms akin to
those of block ciphers.  This is a necessary step before we can
reimplement existing hash algorithms using the new ahash interface.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-07-10 20:35:18 +08:00

195 lines
4.7 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;
walk->offset = 0;
if (nbytes)
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);
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 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 = ahash_setkey;
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_hash.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");