[v3 PATCH 6/16] crypto: cryptd - Add support for skcipher

Herbert Xu
2016-11-22T12:08:37Z

This patch adds skcipher support to cryptd alongside ablkcipher.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

crypto/cryptd.c | 284 +++++++++++++++++++++++++++++++++++++++++++++++-
include/crypto/cryptd.h | 13 ++
2 files changed, 294 insertions(+), 3 deletions(-)

diff --git a/crypto/cryptd.c b/crypto/cryptd.c
index 3fd2a20..0508c48 100644
--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -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>
@@ -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;
@@ -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;
@@ -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);
@@ -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:
@@ -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)
{
diff --git a/include/crypto/cryptd.h b/include/crypto/cryptd.h
index bc792d5..94418cb 100644
--- a/include/crypto/cryptd.h
+++ b/include/crypto/cryptd.h
@@ -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;
@@ -34,6 +34,17 @@ struct cryptd_ablkcipher *cryptd_alloc_ablkcipher(const char *alg_name,
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;
};