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crypto: cryptd - Add support for skcipher
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This patch adds skcipher support to cryptd alongside ablkcipher.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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@herbertx
herbertx committed Nov 28, 2016
1 parent 430b441 commit 4e0958d
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Showing 2 changed files with 294 additions and 3 deletions.
284 changes: 282 additions & 2 deletions crypto/cryptd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,9 +17,9 @@
*
*/

#include <crypto/algapi.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
#include <crypto/cryptd.h>
#include <crypto/crypto_wq.h>
#include <linux/atomic.h>
Expand Down Expand Up @@ -48,6 +48,11 @@ struct cryptd_instance_ctx {
struct cryptd_queue *queue;
};

struct skcipherd_instance_ctx {
struct crypto_skcipher_spawn spawn;
struct cryptd_queue *queue;
};

struct hashd_instance_ctx {
struct crypto_shash_spawn spawn;
struct cryptd_queue *queue;
Expand All @@ -67,6 +72,15 @@ struct cryptd_blkcipher_request_ctx {
crypto_completion_t complete;
};

struct cryptd_skcipher_ctx {
atomic_t refcnt;
struct crypto_skcipher *child;
};

struct cryptd_skcipher_request_ctx {
crypto_completion_t complete;
};

struct cryptd_hash_ctx {
atomic_t refcnt;
struct crypto_shash *child;
Expand Down Expand Up @@ -430,6 +444,216 @@ static int cryptd_create_blkcipher(struct crypto_template *tmpl,
return err;
}

static int cryptd_skcipher_setkey(struct crypto_skcipher *parent,
const u8 *key, unsigned int keylen)
{
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(parent);
struct crypto_skcipher *child = ctx->child;
int err;

crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_skcipher_setkey(child, key, keylen);
crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}

static void cryptd_skcipher_complete(struct skcipher_request *req, int err)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
int refcnt = atomic_read(&ctx->refcnt);

local_bh_disable();
rctx->complete(&req->base, err);
local_bh_enable();

if (err != -EINPROGRESS && refcnt && atomic_dec_and_test(&ctx->refcnt))
crypto_free_skcipher(tfm);
}

static void cryptd_skcipher_encrypt(struct crypto_async_request *base,
int err)
{
struct skcipher_request *req = skcipher_request_cast(base);
struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *child = ctx->child;
SKCIPHER_REQUEST_ON_STACK(subreq, child);

if (unlikely(err == -EINPROGRESS))
goto out;

skcipher_request_set_tfm(subreq, child);
skcipher_request_set_callback(subreq, CRYPTO_TFM_REQ_MAY_SLEEP,
NULL, NULL);
skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
req->iv);

err = crypto_skcipher_encrypt(subreq);
skcipher_request_zero(subreq);

req->base.complete = rctx->complete;

out:
cryptd_skcipher_complete(req, err);
}

static void cryptd_skcipher_decrypt(struct crypto_async_request *base,
int err)
{
struct skcipher_request *req = skcipher_request_cast(base);
struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *child = ctx->child;
SKCIPHER_REQUEST_ON_STACK(subreq, child);

if (unlikely(err == -EINPROGRESS))
goto out;

skcipher_request_set_tfm(subreq, child);
skcipher_request_set_callback(subreq, CRYPTO_TFM_REQ_MAY_SLEEP,
NULL, NULL);
skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
req->iv);

err = crypto_skcipher_decrypt(subreq);
skcipher_request_zero(subreq);

req->base.complete = rctx->complete;

out:
cryptd_skcipher_complete(req, err);
}

static int cryptd_skcipher_enqueue(struct skcipher_request *req,
crypto_completion_t compl)
{
struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct cryptd_queue *queue;

queue = cryptd_get_queue(crypto_skcipher_tfm(tfm));
rctx->complete = req->base.complete;
req->base.complete = compl;

return cryptd_enqueue_request(queue, &req->base);
}

static int cryptd_skcipher_encrypt_enqueue(struct skcipher_request *req)
{
return cryptd_skcipher_enqueue(req, cryptd_skcipher_encrypt);
}

static int cryptd_skcipher_decrypt_enqueue(struct skcipher_request *req)
{
return cryptd_skcipher_enqueue(req, cryptd_skcipher_decrypt);
}

static int cryptd_skcipher_init_tfm(struct crypto_skcipher *tfm)
{
struct skcipher_instance *inst = skcipher_alg_instance(tfm);
struct skcipherd_instance_ctx *ictx = skcipher_instance_ctx(inst);
struct crypto_skcipher_spawn *spawn = &ictx->spawn;
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *cipher;

cipher = crypto_spawn_skcipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);

ctx->child = cipher;
crypto_skcipher_set_reqsize(
tfm, sizeof(struct cryptd_skcipher_request_ctx));
return 0;
}

static void cryptd_skcipher_exit_tfm(struct crypto_skcipher *tfm)
{
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);

crypto_free_skcipher(ctx->child);
}

static void cryptd_skcipher_free(struct skcipher_instance *inst)
{
struct skcipherd_instance_ctx *ctx = skcipher_instance_ctx(inst);

crypto_drop_skcipher(&ctx->spawn);
}

static int cryptd_create_skcipher(struct crypto_template *tmpl,
struct rtattr **tb,
struct cryptd_queue *queue)
{
struct skcipherd_instance_ctx *ctx;
struct skcipher_instance *inst;
struct skcipher_alg *alg;
const char *name;
u32 type;
u32 mask;
int err;

type = 0;
mask = CRYPTO_ALG_ASYNC;

cryptd_check_internal(tb, &type, &mask);

name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(name))
return PTR_ERR(name);

inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
if (!inst)
return -ENOMEM;

ctx = skcipher_instance_ctx(inst);
ctx->queue = queue;

crypto_set_skcipher_spawn(&ctx->spawn, skcipher_crypto_instance(inst));
err = crypto_grab_skcipher(&ctx->spawn, name, type, mask);
if (err)
goto out_free_inst;

alg = crypto_spawn_skcipher_alg(&ctx->spawn);
err = cryptd_init_instance(skcipher_crypto_instance(inst), &alg->base);
if (err)
goto out_drop_skcipher;

inst->alg.base.cra_flags = CRYPTO_ALG_ASYNC |
(alg->base.cra_flags & CRYPTO_ALG_INTERNAL);

inst->alg.ivsize = crypto_skcipher_alg_ivsize(alg);
inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg);
inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg);

inst->alg.base.cra_ctxsize = sizeof(struct cryptd_skcipher_ctx);

inst->alg.init = cryptd_skcipher_init_tfm;
inst->alg.exit = cryptd_skcipher_exit_tfm;

inst->alg.setkey = cryptd_skcipher_setkey;
inst->alg.encrypt = cryptd_skcipher_encrypt_enqueue;
inst->alg.decrypt = cryptd_skcipher_decrypt_enqueue;

inst->free = cryptd_skcipher_free;

err = skcipher_register_instance(tmpl, inst);
if (err) {
out_drop_skcipher:
crypto_drop_skcipher(&ctx->spawn);
out_free_inst:
kfree(inst);
}
return err;
}

static int cryptd_hash_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
Expand Down Expand Up @@ -893,7 +1117,11 @@ static int cryptd_create(struct crypto_template *tmpl, struct rtattr **tb)

switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
case CRYPTO_ALG_TYPE_BLKCIPHER:
return cryptd_create_blkcipher(tmpl, tb, &queue);
if ((algt->type & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER)
return cryptd_create_blkcipher(tmpl, tb, &queue);

return cryptd_create_skcipher(tmpl, tb, &queue);
case CRYPTO_ALG_TYPE_DIGEST:
return cryptd_create_hash(tmpl, tb, &queue);
case CRYPTO_ALG_TYPE_AEAD:
Expand Down Expand Up @@ -983,6 +1211,58 @@ void cryptd_free_ablkcipher(struct cryptd_ablkcipher *tfm)
}
EXPORT_SYMBOL_GPL(cryptd_free_ablkcipher);

struct cryptd_skcipher *cryptd_alloc_skcipher(const char *alg_name,
u32 type, u32 mask)
{
char cryptd_alg_name[CRYPTO_MAX_ALG_NAME];
struct cryptd_skcipher_ctx *ctx;
struct crypto_skcipher *tfm;

if (snprintf(cryptd_alg_name, CRYPTO_MAX_ALG_NAME,
"cryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
return ERR_PTR(-EINVAL);

tfm = crypto_alloc_skcipher(cryptd_alg_name, type, mask);
if (IS_ERR(tfm))
return ERR_CAST(tfm);

if (tfm->base.__crt_alg->cra_module != THIS_MODULE) {
crypto_free_skcipher(tfm);
return ERR_PTR(-EINVAL);
}

ctx = crypto_skcipher_ctx(tfm);
atomic_set(&ctx->refcnt, 1);

return container_of(tfm, struct cryptd_skcipher, base);
}
EXPORT_SYMBOL_GPL(cryptd_alloc_skcipher);

struct crypto_skcipher *cryptd_skcipher_child(struct cryptd_skcipher *tfm)
{
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);

return ctx->child;
}
EXPORT_SYMBOL_GPL(cryptd_skcipher_child);

bool cryptd_skcipher_queued(struct cryptd_skcipher *tfm)
{
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);

return atomic_read(&ctx->refcnt) - 1;
}
EXPORT_SYMBOL_GPL(cryptd_skcipher_queued);

void cryptd_free_skcipher(struct cryptd_skcipher *tfm)
{
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);

if (atomic_dec_and_test(&ctx->refcnt))
crypto_free_skcipher(&tfm->base);
}
EXPORT_SYMBOL_GPL(cryptd_free_skcipher);

struct cryptd_ahash *cryptd_alloc_ahash(const char *alg_name,
u32 type, u32 mask)
{
Expand Down
13 changes: 12 additions & 1 deletion include/crypto/cryptd.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12,10 +12,10 @@
#ifndef _CRYPTO_CRYPT_H
#define _CRYPTO_CRYPT_H

#include <linux/crypto.h>
#include <linux/kernel.h>
#include <crypto/aead.h>
#include <crypto/hash.h>
#include <crypto/skcipher.h>

struct cryptd_ablkcipher {
struct crypto_ablkcipher base;
Expand All @@ -34,6 +34,17 @@ struct crypto_blkcipher *cryptd_ablkcipher_child(struct cryptd_ablkcipher *tfm);
bool cryptd_ablkcipher_queued(struct cryptd_ablkcipher *tfm);
void cryptd_free_ablkcipher(struct cryptd_ablkcipher *tfm);

struct cryptd_skcipher {
struct crypto_skcipher base;
};

struct cryptd_skcipher *cryptd_alloc_skcipher(const char *alg_name,
u32 type, u32 mask);
struct crypto_skcipher *cryptd_skcipher_child(struct cryptd_skcipher *tfm);
/* Must be called without moving CPUs. */
bool cryptd_skcipher_queued(struct cryptd_skcipher *tfm);
void cryptd_free_skcipher(struct cryptd_skcipher *tfm);

struct cryptd_ahash {
struct crypto_ahash base;
};
Expand Down

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