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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Asynchronous Cryptographic Hash operations.
*
* This is the implementation of the ahash (asynchronous hash) API. It differs
* from shash (synchronous hash) in that ahash supports asynchronous operations,
* and it hashes data from scatterlists instead of virtually addressed buffers.
*
* The ahash API provides access to both ahash and shash algorithms. The shash
* API only provides access to shash algorithms.
*
* Copyright (c) 2008 Loc Ho <lho@amcc.com>
*/
#include <crypto/scatterwalk.h>
#include <linux/cryptouser.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/string.h>
#include <net/netlink.h>
#include "hash.h"
#define CRYPTO_ALG_TYPE_AHASH_MASK 0x0000000e
static inline struct crypto_istat_hash *ahash_get_stat(struct ahash_alg *alg)
{
return hash_get_stat(&alg->halg);
}
static inline int crypto_ahash_errstat(struct ahash_alg *alg, int err)
{
if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
return err;
if (err && err != -EINPROGRESS && err != -EBUSY)
atomic64_inc(&ahash_get_stat(alg)->err_cnt);
return err;
}
/*
* For an ahash tfm that is using an shash algorithm (instead of an ahash
* algorithm), this returns the underlying shash tfm.
*/
static inline struct crypto_shash *ahash_to_shash(struct crypto_ahash *tfm)
{
return *(struct crypto_shash **)crypto_ahash_ctx(tfm);
}
static inline struct shash_desc *prepare_shash_desc(struct ahash_request *req,
struct crypto_ahash *tfm)
{
struct shash_desc *desc = ahash_request_ctx(req);
desc->tfm = ahash_to_shash(tfm);
return desc;
}
int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
{
struct crypto_hash_walk walk;
int nbytes;
for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
nbytes = crypto_hash_walk_done(&walk, nbytes))
nbytes = crypto_shash_update(desc, walk.data, nbytes);
return nbytes;
}
EXPORT_SYMBOL_GPL(shash_ahash_update);
int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
{
struct crypto_hash_walk walk;
int nbytes;
nbytes = crypto_hash_walk_first(req, &walk);
if (!nbytes)
return crypto_shash_final(desc, req->result);
do {
nbytes = crypto_hash_walk_last(&walk) ?
crypto_shash_finup(desc, walk.data, nbytes,
req->result) :
crypto_shash_update(desc, walk.data, nbytes);
nbytes = crypto_hash_walk_done(&walk, nbytes);
} while (nbytes > 0);
return nbytes;
}
EXPORT_SYMBOL_GPL(shash_ahash_finup);
int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
{
unsigned int nbytes = req->nbytes;
struct scatterlist *sg;
unsigned int offset;
int err;
if (nbytes &&
(sg = req->src, offset = sg->offset,
nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
void *data;
data = kmap_local_page(sg_page(sg));
err = crypto_shash_digest(desc, data + offset, nbytes,
req->result);
kunmap_local(data);
} else
err = crypto_shash_init(desc) ?:
shash_ahash_finup(req, desc);
return err;
}
EXPORT_SYMBOL_GPL(shash_ahash_digest);
static void crypto_exit_ahash_using_shash(struct crypto_tfm *tfm)
{
struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
crypto_free_shash(*ctx);
}
static int crypto_init_ahash_using_shash(struct crypto_tfm *tfm)
{
struct crypto_alg *calg = tfm->__crt_alg;
struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
struct crypto_shash *shash;
if (!crypto_mod_get(calg))
return -EAGAIN;
shash = crypto_create_tfm(calg, &crypto_shash_type);
if (IS_ERR(shash)) {
crypto_mod_put(calg);
return PTR_ERR(shash);
}
crt->using_shash = true;
*ctx = shash;
tfm->exit = crypto_exit_ahash_using_shash;
crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
CRYPTO_TFM_NEED_KEY);
crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
return 0;
}
static int hash_walk_next(struct crypto_hash_walk *walk)
{
unsigned int offset = walk->offset;
unsigned int nbytes = min(walk->entrylen,
((unsigned int)(PAGE_SIZE)) - offset);
walk->data = kmap_local_page(walk->pg);
walk->data += offset;
walk->entrylen -= nbytes;
return nbytes;
}
static int hash_walk_new_entry(struct crypto_hash_walk *walk)
{
struct scatterlist *sg;
sg = walk->sg;
walk->offset = sg->offset;
walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
walk->offset = offset_in_page(walk->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)
{
walk->data -= walk->offset;
kunmap_local(walk->data);
crypto_yield(walk->flags);
if (err)
return err;
if (walk->entrylen) {
walk->offset = 0;
walk->pg++;
return hash_walk_next(walk);
}
if (!walk->total)
return 0;
walk->sg = 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) {
walk->entrylen = 0;
return 0;
}
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_nosetkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen)
{
return -ENOSYS;
}
static void ahash_set_needkey(struct crypto_ahash *tfm, struct ahash_alg *alg)
{
if (alg->setkey != ahash_nosetkey &&
!(alg->halg.base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
}
int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen)
{
if (likely(tfm->using_shash)) {
struct crypto_shash *shash = ahash_to_shash(tfm);
int err;
err = crypto_shash_setkey(shash, key, keylen);
if (unlikely(err)) {
crypto_ahash_set_flags(tfm,
crypto_shash_get_flags(shash) &
CRYPTO_TFM_NEED_KEY);
return err;
}
} else {
struct ahash_alg *alg = crypto_ahash_alg(tfm);
int err;
err = alg->setkey(tfm, key, keylen);
if (unlikely(err)) {
ahash_set_needkey(tfm, alg);
return err;
}
}
crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
int crypto_ahash_init(struct ahash_request *req)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
if (likely(tfm->using_shash))
return crypto_shash_init(prepare_shash_desc(req, tfm));
if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
return -ENOKEY;
return crypto_ahash_alg(tfm)->init(req);
}
EXPORT_SYMBOL_GPL(crypto_ahash_init);
static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt,
bool has_state)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
unsigned int ds = crypto_ahash_digestsize(tfm);
struct ahash_request *subreq;
unsigned int subreq_size;
unsigned int reqsize;
u8 *result;
gfp_t gfp;
u32 flags;
subreq_size = sizeof(*subreq);
reqsize = crypto_ahash_reqsize(tfm);
reqsize = ALIGN(reqsize, crypto_tfm_ctx_alignment());
subreq_size += reqsize;
subreq_size += ds;
flags = ahash_request_flags(req);
gfp = (flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? GFP_KERNEL : GFP_ATOMIC;
subreq = kmalloc(subreq_size, gfp);
if (!subreq)
return -ENOMEM;
ahash_request_set_tfm(subreq, tfm);
ahash_request_set_callback(subreq, flags, cplt, req);
result = (u8 *)(subreq + 1) + reqsize;
ahash_request_set_crypt(subreq, req->src, result, req->nbytes);
if (has_state) {
void *state;
state = kmalloc(crypto_ahash_statesize(tfm), gfp);
if (!state) {
kfree(subreq);
return -ENOMEM;
}
crypto_ahash_export(req, state);
crypto_ahash_import(subreq, state);
kfree_sensitive(state);
}
req->priv = subreq;
return 0;
}
static void ahash_restore_req(struct ahash_request *req, int err)
{
struct ahash_request *subreq = req->priv;
if (!err)
memcpy(req->result, subreq->result,
crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
req->priv = NULL;
kfree_sensitive(subreq);
}
int crypto_ahash_update(struct ahash_request *req)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ahash_alg *alg;
if (likely(tfm->using_shash))
return shash_ahash_update(req, ahash_request_ctx(req));
alg = crypto_ahash_alg(tfm);
if (IS_ENABLED(CONFIG_CRYPTO_STATS))
atomic64_add(req->nbytes, &ahash_get_stat(alg)->hash_tlen);
return crypto_ahash_errstat(alg, alg->update(req));
}
EXPORT_SYMBOL_GPL(crypto_ahash_update);
int crypto_ahash_final(struct ahash_request *req)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ahash_alg *alg;
if (likely(tfm->using_shash))
return crypto_shash_final(ahash_request_ctx(req), req->result);
alg = crypto_ahash_alg(tfm);
if (IS_ENABLED(CONFIG_CRYPTO_STATS))
atomic64_inc(&ahash_get_stat(alg)->hash_cnt);
return crypto_ahash_errstat(alg, alg->final(req));
}
EXPORT_SYMBOL_GPL(crypto_ahash_final);
int crypto_ahash_finup(struct ahash_request *req)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ahash_alg *alg;
if (likely(tfm->using_shash))
return shash_ahash_finup(req, ahash_request_ctx(req));
alg = crypto_ahash_alg(tfm);
if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
struct crypto_istat_hash *istat = ahash_get_stat(alg);
atomic64_inc(&istat->hash_cnt);
atomic64_add(req->nbytes, &istat->hash_tlen);
}
return crypto_ahash_errstat(alg, alg->finup(req));
}
EXPORT_SYMBOL_GPL(crypto_ahash_finup);
int crypto_ahash_digest(struct ahash_request *req)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ahash_alg *alg;
int err;
if (likely(tfm->using_shash))
return shash_ahash_digest(req, prepare_shash_desc(req, tfm));
alg = crypto_ahash_alg(tfm);
if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
struct crypto_istat_hash *istat = ahash_get_stat(alg);
atomic64_inc(&istat->hash_cnt);
atomic64_add(req->nbytes, &istat->hash_tlen);
}
if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
err = -ENOKEY;
else
err = alg->digest(req);
return crypto_ahash_errstat(alg, err);
}
EXPORT_SYMBOL_GPL(crypto_ahash_digest);
static void ahash_def_finup_done2(void *data, int err)
{
struct ahash_request *areq = data;
if (err == -EINPROGRESS)
return;
ahash_restore_req(areq, err);
ahash_request_complete(areq, err);
}
static int ahash_def_finup_finish1(struct ahash_request *req, int err)
{
struct ahash_request *subreq = req->priv;
if (err)
goto out;
subreq->base.complete = ahash_def_finup_done2;
err = crypto_ahash_alg(crypto_ahash_reqtfm(req))->final(subreq);
if (err == -EINPROGRESS || err == -EBUSY)
return err;
out:
ahash_restore_req(req, err);
return err;
}
static void ahash_def_finup_done1(void *data, int err)
{
struct ahash_request *areq = data;
struct ahash_request *subreq;
if (err == -EINPROGRESS)
goto out;
subreq = areq->priv;
subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
err = ahash_def_finup_finish1(areq, err);
if (err == -EINPROGRESS || err == -EBUSY)
return;
out:
ahash_request_complete(areq, 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, true);
if (err)
return err;
err = crypto_ahash_alg(tfm)->update(req->priv);
if (err == -EINPROGRESS || err == -EBUSY)
return err;
return ahash_def_finup_finish1(req, err);
}
int crypto_ahash_export(struct ahash_request *req, void *out)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
if (likely(tfm->using_shash))
return crypto_shash_export(ahash_request_ctx(req), out);
return crypto_ahash_alg(tfm)->export(req, out);
}
EXPORT_SYMBOL_GPL(crypto_ahash_export);
int crypto_ahash_import(struct ahash_request *req, const void *in)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
if (likely(tfm->using_shash))
return crypto_shash_import(prepare_shash_desc(req, tfm), in);
if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
return -ENOKEY;
return crypto_ahash_alg(tfm)->import(req, in);
}
EXPORT_SYMBOL_GPL(crypto_ahash_import);
static void crypto_ahash_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
struct ahash_alg *alg = crypto_ahash_alg(hash);
alg->exit_tfm(hash);
}
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);
crypto_ahash_set_statesize(hash, alg->halg.statesize);
if (tfm->__crt_alg->cra_type == &crypto_shash_type)
return crypto_init_ahash_using_shash(tfm);
ahash_set_needkey(hash, alg);
if (alg->exit_tfm)
tfm->exit = crypto_ahash_exit_tfm;
return alg->init_tfm ? alg->init_tfm(hash) : 0;
}
static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
{
if (alg->cra_type == &crypto_shash_type)
return sizeof(struct crypto_shash *);
return crypto_alg_extsize(alg);
}
static void crypto_ahash_free_instance(struct crypto_instance *inst)
{
struct ahash_instance *ahash = ahash_instance(inst);
ahash->free(ahash);
}
static int __maybe_unused crypto_ahash_report(
struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_hash rhash;
memset(&rhash, 0, sizeof(rhash));
strscpy(rhash.type, "ahash", sizeof(rhash.type));
rhash.blocksize = alg->cra_blocksize;
rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
}
static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
__maybe_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);
}
static int __maybe_unused crypto_ahash_report_stat(
struct sk_buff *skb, struct crypto_alg *alg)
{
return crypto_hash_report_stat(skb, alg, "ahash");
}
static const struct crypto_type crypto_ahash_type = {
.extsize = crypto_ahash_extsize,
.init_tfm = crypto_ahash_init_tfm,
.free = crypto_ahash_free_instance,
#ifdef CONFIG_PROC_FS
.show = crypto_ahash_show,
#endif
#if IS_ENABLED(CONFIG_CRYPTO_USER)
.report = crypto_ahash_report,
#endif
#ifdef CONFIG_CRYPTO_STATS
.report_stat = crypto_ahash_report_stat,
#endif
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
.type = CRYPTO_ALG_TYPE_AHASH,
.tfmsize = offsetof(struct crypto_ahash, base),
};
int crypto_grab_ahash(struct crypto_ahash_spawn *spawn,
struct crypto_instance *inst,
const char *name, u32 type, u32 mask)
{
spawn->base.frontend = &crypto_ahash_type;
return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_grab_ahash);
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);
int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
{
return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_has_ahash);
struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *hash)
{
struct hash_alg_common *halg = crypto_hash_alg_common(hash);
struct crypto_tfm *tfm = crypto_ahash_tfm(hash);
struct crypto_ahash *nhash;
struct ahash_alg *alg;
int err;
if (!crypto_hash_alg_has_setkey(halg)) {
tfm = crypto_tfm_get(tfm);
if (IS_ERR(tfm))
return ERR_CAST(tfm);
return hash;
}
nhash = crypto_clone_tfm(&crypto_ahash_type, tfm);
if (IS_ERR(nhash))
return nhash;
nhash->reqsize = hash->reqsize;
nhash->statesize = hash->statesize;
if (likely(hash->using_shash)) {
struct crypto_shash **nctx = crypto_ahash_ctx(nhash);
struct crypto_shash *shash;
shash = crypto_clone_shash(ahash_to_shash(hash));
if (IS_ERR(shash)) {
err = PTR_ERR(shash);
goto out_free_nhash;
}
nhash->using_shash = true;
*nctx = shash;
return nhash;
}
err = -ENOSYS;
alg = crypto_ahash_alg(hash);
if (!alg->clone_tfm)
goto out_free_nhash;
err = alg->clone_tfm(nhash, hash);
if (err)
goto out_free_nhash;
return nhash;
out_free_nhash:
crypto_free_ahash(nhash);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_clone_ahash);
static int ahash_prepare_alg(struct ahash_alg *alg)
{
struct crypto_alg *base = &alg->halg.base;
int err;
if (alg->halg.statesize == 0)
return -EINVAL;
err = hash_prepare_alg(&alg->halg);
if (err)
return err;
base->cra_type = &crypto_ahash_type;
base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
if (!alg->finup)
alg->finup = ahash_def_finup;
if (!alg->setkey)
alg->setkey = ahash_nosetkey;
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);
void crypto_unregister_ahash(struct ahash_alg *alg)
{
crypto_unregister_alg(&alg->halg.base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
int crypto_register_ahashes(struct ahash_alg *algs, int count)
{
int i, ret;
for (i = 0; i < count; i++) {
ret = crypto_register_ahash(&algs[i]);
if (ret)
goto err;
}
return 0;
err:
for (--i; i >= 0; --i)
crypto_unregister_ahash(&algs[i]);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_ahashes);
void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
{
int i;
for (i = count - 1; i >= 0; --i)
crypto_unregister_ahash(&algs[i]);
}
EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
int ahash_register_instance(struct crypto_template *tmpl,
struct ahash_instance *inst)
{
int err;
if (WARN_ON(!inst->free))
return -EINVAL;
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);
bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
{
struct crypto_alg *alg = &halg->base;
if (alg->cra_type == &crypto_shash_type)
return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
return __crypto_ahash_alg(alg)->setkey != ahash_nosetkey;
}
EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Asynchronous cryptographic hash type");