// SPDX-License-Identifier: GPL-2.0-or-later

/*

* 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>

*/

#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 <linux/compiler.h>

#include <net/netlink.h>

#include "internal.h"

static const struct crypto_type crypto_ahash_type;

struct ahash_request_priv {

};

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->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)

{

unsigned int alignmask = walk->alignmask;

walk->data -= walk->offset;

if (walk->entrylen && (walk->offset & alignmask) && !err) {

unsigned int nbytes;

walk->offset = ALIGN(walk->offset, alignmask + 1);

nbytes = min(walk->entrylen,

(unsigned int)(PAGE_SIZE - walk->offset));

if (nbytes) {

walk->entrylen -= nbytes;

walk->data += walk->offset;

return nbytes;

}

}

kunmap_atomic(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->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)

{

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);

kfree_sensitive(buffer);

return ret;

}

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)

{

const struct hash_alg_common *alg = crypto_hash_alg_common(tfm);

if (tfm->setkey != ahash_nosetkey &&

!(alg->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)

{

unsigned long alignmask = crypto_ahash_alignmask(tfm);

int err;

if ((unsigned long)key & alignmask)

err = ahash_setkey_unaligned(tfm, key, keylen);

else

err = tfm->setkey(tfm, key, keylen);

if (unlikely(err)) {

ahash_set_needkey(tfm);

return err;

}

crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);

return 0;

}

EXPORT_SYMBOL_GPL(crypto_ahash_setkey);

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;

priv->flags = req->base.flags;

/*

* 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, int err)

{

struct ahash_request_priv *priv = req->priv;

if (!err)

memcpy(priv->result, req->result,

crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));

/* Restore the original crypto request. */

req->result = priv->result;

ahash_request_set_callback(req, priv->flags,

priv->complete, priv->data);

req->priv = NULL;

/* Free the req->priv.priv from the ADJUSTED request. */

kfree_sensitive(priv);

}

static void ahash_notify_einprogress(struct ahash_request *req)

{

struct ahash_request_priv *priv = req->priv;

struct crypto_async_request oreq;

oreq.data = priv->data;

priv->complete(&oreq, -EINPROGRESS);

}

static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)

{

struct ahash_request *areq = req->data;

if (err == -EINPROGRESS) {

ahash_notify_einprogress(areq);

return;

}

/*

* 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_restore_req(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);

if (err == -EINPROGRESS || err == -EBUSY)

return err;

ahash_restore_req(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)

{

struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);

struct crypto_alg *alg = tfm->base.__crt_alg;

unsigned int nbytes = req->nbytes;

int ret;

crypto_stats_get(alg);

ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);

crypto_stats_ahash_final(nbytes, ret, alg);

return ret;

}

EXPORT_SYMBOL_GPL(crypto_ahash_final);

int crypto_ahash_finup(struct ahash_request *req)

{

struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);

struct crypto_alg *alg = tfm->base.__crt_alg;

unsigned int nbytes = req->nbytes;

int ret;

crypto_stats_get(alg);

ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);

crypto_stats_ahash_final(nbytes, ret, alg);

return ret;

}

EXPORT_SYMBOL_GPL(crypto_ahash_finup);

int crypto_ahash_digest(struct ahash_request *req)

{

struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);

struct crypto_alg *alg = tfm->base.__crt_alg;

unsigned int nbytes = req->nbytes;

int ret;

crypto_stats_get(alg);

if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)

ret = -ENOKEY;

else

ret = crypto_ahash_op(req, tfm->digest);

crypto_stats_ahash_final(nbytes, ret, alg);

return ret;

}

EXPORT_SYMBOL_GPL(crypto_ahash_digest);

static void ahash_def_finup_done2(struct crypto_async_request *req, int err)

{

struct ahash_request *areq = req->data;

if (err == -EINPROGRESS)

return;

ahash_restore_req(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;

err = crypto_ahash_reqtfm(req)->final(req);

if (err == -EINPROGRESS || err == -EBUSY)

return err;

out:

ahash_restore_req(req, err);

return err;

}

static void ahash_def_finup_done1(struct crypto_async_request *req, int err)

{

struct ahash_request *areq = req->data;

if (err == -EINPROGRESS) {

ahash_notify_einprogress(areq);

return;

}

areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;

err = ahash_def_finup_finish1(areq, err);

if (areq->priv)

return;

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);

if (err == -EINPROGRESS || err == -EBUSY)

return err;

return ahash_def_finup_finish1(req, err);

}

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);

hash->setkey = ahash_nosetkey;

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;

hash->export = alg->export;

hash->import = alg->import;

if (alg->setkey) {

hash->setkey = alg->setkey;

ahash_set_needkey(hash);

}

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_ahash_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);

}

#ifdef CONFIG_NET

static int 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);

}

#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)

__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 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

.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),

};

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);

static int ahash_prepare_alg(struct ahash_alg *alg)

{

struct crypto_alg *base = &alg->halg.base;

if (alg->halg.digestsize > HASH_MAX_DIGESTSIZE ||

alg->halg.statesize > HASH_MAX_STATESIZE ||

alg->halg.statesize == 0)

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);

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_ahash_type)

return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));

return __crypto_ahash_alg(alg)->setkey != NULL;

}

EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);

MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("Asynchronous cryptographic hash type");