linux/crypto/ahash.c
Herbert Xu 01c2dece43 crypto: ahash - Add instance/spawn support
This patch adds support for creating ahash instances and using
ahash as spawns.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14 15:54:09 +08:00

336 lines
8.2 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 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 = 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;
}
static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
struct old_ahash_alg *alg = &tfm->__crt_alg->cra_ahash;
struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
struct ahash_alg *nalg = crypto_ahash_alg(crt);
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;
nalg->setkey = alg->setkey;
nalg->halg.digestsize = alg->digestsize;
return 0;
}
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);
struct old_ahash_alg *oalg = crypto_old_ahash_alg(hash);
if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
return crypto_init_shash_ops_async(tfm);
if (oalg->init)
return crypto_init_ahash_ops(tfm, 0, 0);
hash->init = alg->init;
hash->update = alg->update;
hash->final = alg->final;
hash->digest = alg->digest;
hash->setkey = alg->setkey ? ahash_setkey : ahash_nosetkey;
hash->digestsize = alg->halg.digestsize;
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 *);
}
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
.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");