Hi Ard,
ut 18. 6. 2019 o 23:28 Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> napísal(a):
> Implement a template that wraps a (skcipher,cipher,shash) or
> (aead,cipher,shash) tuple so that we can consolidate the ESSIV handling
> in fscrypt and dm-crypt and move it into the crypto API. This will result
> in better test coverage, and will allow future changes to make the bare
> cipher interface internal to the crypto subsystem, in order to increase
> robustness of the API against misuse.
>
> Note that especially the AEAD handling is a bit complex, and is tightly
> coupled to the way dm-crypt combines AEAD based on the authenc() template
> with the ESSIV handling.
Wouldn't it work better to have a template only for skcipher and in
dm-crypt just inject the essiv() template into the cipher string? For
example: "authenc(hmac(sha256),cbc(aes))-essiv:sha256" ->
"authenc(hmac(sha256),essiv(cbc(aes),aes,sha256))". That seems to me a
much simpler hack. (But maybe I'm missing some issue in that
approach...)
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> ---
> crypto/Kconfig | 4 +
> crypto/Makefile | 1 +
> crypto/essiv.c | 624 ++++++++++++++++++++
> 3 files changed, 629 insertions(+)
>
> diff --git a/crypto/Kconfig b/crypto/Kconfig
> index 3d056e7da65f..1aa47087c1a2 100644
> --- a/crypto/Kconfig
> +++ b/crypto/Kconfig
> @@ -1917,6 +1917,10 @@ config CRYPTO_STATS
> config CRYPTO_HASH_INFO
> bool
>
> +config CRYPTO_ESSIV
> + tristate
> + select CRYPTO_AUTHENC
> +
> source "drivers/crypto/Kconfig"
> source "crypto/asymmetric_keys/Kconfig"
> source "certs/Kconfig"
> diff --git a/crypto/Makefile b/crypto/Makefile
> index 266a4cdbb9e2..ad1d99ba6d56 100644
> --- a/crypto/Makefile
> +++ b/crypto/Makefile
> @@ -148,6 +148,7 @@ obj-$(CONFIG_CRYPTO_USER_API_AEAD) += algif_aead.o
> obj-$(CONFIG_CRYPTO_ZSTD) += zstd.o
> obj-$(CONFIG_CRYPTO_OFB) += ofb.o
> obj-$(CONFIG_CRYPTO_ECC) += ecc.o
> +obj-$(CONFIG_CRYPTO_ESSIV) += essiv.o
>
> ecdh_generic-y += ecdh.o
> ecdh_generic-y += ecdh_helper.o
> diff --git a/crypto/essiv.c b/crypto/essiv.c
> new file mode 100644
> index 000000000000..029a65afb4d7
> --- /dev/null
> +++ b/crypto/essiv.c
> @@ -0,0 +1,624 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ESSIV skcipher template for block encryption
> + *
> + * Copyright (c) 2019 Linaro, Ltd. <ard.biesheuvel@xxxxxxxxxx>
> + *
> + * Heavily based on:
> + * adiantum length-preserving encryption mode
> + *
> + * Copyright 2018 Google LLC
> + */
> +
> +#include <crypto/authenc.h>
> +#include <crypto/internal/aead.h>
> +#include <crypto/internal/hash.h>
> +#include <crypto/internal/skcipher.h>
> +#include <crypto/scatterwalk.h>
> +#include <linux/module.h>
> +
> +#include "internal.h"
> +
> +#define ESSIV_IV_SIZE sizeof(u64) // IV size of the outer algo
> +#define MAX_INNER_IV_SIZE 16 // max IV size of inner algo
> +
> +struct essiv_instance_ctx {
> + union {
> + struct crypto_skcipher_spawn blockcipher_spawn;
> + struct crypto_aead_spawn aead_spawn;
> + } u;
> + struct crypto_spawn essiv_cipher_spawn;
> + struct crypto_shash_spawn hash_spawn;
> +};
> +
> +struct essiv_tfm_ctx {
> + union {
> + struct crypto_skcipher *blockcipher;
> + struct crypto_aead *aead;
> + } u;
> + struct crypto_cipher *essiv_cipher;
> + struct crypto_shash *hash;
> +};
> +
> +struct essiv_skcipher_request_ctx {
> + u8 iv[MAX_INNER_IV_SIZE];
> + struct skcipher_request blockcipher_req;
> +};
> +
> +struct essiv_aead_request_ctx {
> + u8 iv[MAX_INNER_IV_SIZE];
> + struct scatterlist src[4], dst[4];
> + struct aead_request aead_req;
> +};
> +
> +static int essiv_skcipher_setkey(struct crypto_skcipher *tfm,
> + const u8 *key, unsigned int keylen)
> +{
> + u32 flags = crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_REQ_MASK;
> + struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
> + SHASH_DESC_ON_STACK(desc, tctx->hash);
> + unsigned int saltsize;
> + u8 *salt;
> + int err;
> +
> + crypto_skcipher_clear_flags(tctx->u.blockcipher, CRYPTO_TFM_REQ_MASK);
> + crypto_skcipher_set_flags(tctx->u.blockcipher, flags);
> + err = crypto_skcipher_setkey(tctx->u.blockcipher, key, keylen);
> + crypto_skcipher_set_flags(tfm,
> + crypto_skcipher_get_flags(tctx->u.blockcipher) &
> + CRYPTO_TFM_RES_MASK);
> + if (err)
> + return err;
> +
> + saltsize = crypto_shash_digestsize(tctx->hash);
> + salt = kmalloc(saltsize, GFP_KERNEL);
> + if (!salt)
> + return -ENOMEM;
> +
> + desc->tfm = tctx->hash;
> + crypto_shash_digest(desc, key, keylen, salt);
> +
> + crypto_cipher_clear_flags(tctx->essiv_cipher, CRYPTO_TFM_REQ_MASK);
> + crypto_cipher_set_flags(tctx->essiv_cipher, flags & CRYPTO_TFM_REQ_MASK);
> + err = crypto_cipher_setkey(tctx->essiv_cipher, salt, saltsize);
> + flags = crypto_cipher_get_flags(tctx->essiv_cipher) & CRYPTO_TFM_RES_MASK;
> + crypto_skcipher_set_flags(tfm, flags);
> +
> + kzfree(salt);
> + return err;
> +}
> +
> +static int essiv_aead_setkey(struct crypto_aead *tfm, const u8 *key,
> + unsigned int keylen)
> +{
> + struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
> + SHASH_DESC_ON_STACK(desc, tctx->hash);
> + struct crypto_authenc_keys keys;
> + unsigned int saltsize;
> + u8 *salt;
> + int err;
> +
> + crypto_aead_clear_flags(tctx->u.aead, CRYPTO_TFM_REQ_MASK);
> + crypto_aead_set_flags(tctx->u.aead, crypto_aead_get_flags(tfm) &
> + CRYPTO_TFM_REQ_MASK);
> + err = crypto_aead_setkey(tctx->u.aead, key, keylen);
> + crypto_aead_set_flags(tfm, crypto_aead_get_flags(tctx->u.aead) &
> + CRYPTO_TFM_RES_MASK);
> + if (err)
> + return err;
> +
> + if (crypto_authenc_extractkeys(&keys, key, keylen) != 0) {
> + crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
> + return -EINVAL;
> + }
> +
> + saltsize = crypto_shash_digestsize(tctx->hash);
> + salt = kmalloc(saltsize, GFP_KERNEL);
> + if (!salt)
> + return -ENOMEM;
> +
> + desc->tfm = tctx->hash;
> + crypto_shash_init(desc);
> + crypto_shash_update(desc, keys.enckey, keys.enckeylen);
> + crypto_shash_finup(desc, keys.authkey, keys.authkeylen, salt);
> +
> + crypto_cipher_clear_flags(tctx->essiv_cipher, CRYPTO_TFM_REQ_MASK);
> + crypto_cipher_set_flags(tctx->essiv_cipher, crypto_aead_get_flags(tfm) &
> + CRYPTO_TFM_REQ_MASK);
> + err = crypto_cipher_setkey(tctx->essiv_cipher, salt, saltsize);
> + crypto_aead_set_flags(tfm, crypto_cipher_get_flags(tctx->essiv_cipher) &
> + CRYPTO_TFM_RES_MASK);
> +
> + kzfree(salt);
> + return err;
> +}
> +
> +static int essiv_aead_setauthsize(struct crypto_aead *tfm,
> + unsigned int authsize)
> +{
> + struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
> +
> + return crypto_aead_setauthsize(tctx->u.aead, authsize);
> +}
> +
> +static void essiv_skcipher_done(struct crypto_async_request *areq, int err)
> +{
> + struct skcipher_request *req = areq->data;
> +
> + skcipher_request_complete(req, err);
> +}
> +
> +static void essiv_aead_done(struct crypto_async_request *areq, int err)
> +{
> + struct aead_request *req = areq->data;
> +
> + aead_request_complete(req, err);
> +}
> +
> +static void essiv_skcipher_prepare_subreq(struct skcipher_request *req)
> +{
> + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
> + const struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
> + struct essiv_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
> + struct skcipher_request *subreq = &rctx->blockcipher_req;
> +
> + memset(rctx->iv, 0, crypto_cipher_blocksize(tctx->essiv_cipher));
> + memcpy(rctx->iv, req->iv, crypto_skcipher_ivsize(tfm));
> +
> + crypto_cipher_encrypt_one(tctx->essiv_cipher, rctx->iv, rctx->iv);
> +
> + skcipher_request_set_tfm(subreq, tctx->u.blockcipher);
> + skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
> + rctx->iv);
> + skcipher_request_set_callback(subreq, req->base.flags,
> + essiv_skcipher_done, req);
> +}
> +
> +static int essiv_aead_prepare_subreq(struct aead_request *req)
> +{
> + struct crypto_aead *tfm = crypto_aead_reqtfm(req);
> + const struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
> + struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
> + int ivsize = crypto_cipher_blocksize(tctx->essiv_cipher);
> + int ssize = req->assoclen - crypto_aead_ivsize(tfm);
> + struct aead_request *subreq = &rctx->aead_req;
> + struct scatterlist *sg;
> +
> + /*
> + * dm-crypt embeds the sector number and the IV in the AAD region so we
> + * have to splice the converted IV into the subrequest that we pass on
> + * to the AEAD transform. This means we are tightly coupled to dm-crypt,
> + * but that should be the only user of this code in AEAD mode.
> + */
> + if (ssize < 0 || sg_nents_for_len(req->src, ssize) != 1)
> + return -EINVAL;
> +
> + memset(rctx->iv, 0, ivsize);
> + memcpy(rctx->iv, req->iv, crypto_aead_ivsize(tfm));
> +
> + crypto_cipher_encrypt_one(tctx->essiv_cipher, rctx->iv, rctx->iv);
> +
> + sg_init_table(rctx->src, 4);
> + sg_set_page(rctx->src, sg_page(req->src), ssize, req->src->offset);
> + sg_set_buf(rctx->src + 1, rctx->iv, ivsize);
> + sg = scatterwalk_ffwd(rctx->src + 2, req->src, req->assoclen);
> + if (sg != rctx->src + 2)
> + sg_chain(rctx->src, 3, sg);
> +
> + sg_init_table(rctx->dst, 4);
> + sg_set_page(rctx->dst, sg_page(req->dst), ssize, req->dst->offset);
> + sg_set_buf(rctx->dst + 1, rctx->iv, ivsize);
> + sg = scatterwalk_ffwd(rctx->dst + 2, req->dst, req->assoclen);
> + if (sg != rctx->dst + 2)
> + sg_chain(rctx->dst, 3, sg);
> +
> + aead_request_set_tfm(subreq, tctx->u.aead);
> + aead_request_set_crypt(subreq, rctx->src, rctx->dst, req->cryptlen,
> + rctx->iv);
> + aead_request_set_ad(subreq, ssize + ivsize);
> + aead_request_set_callback(subreq, req->base.flags, essiv_aead_done, req);
> +
> + return 0;
> +}
> +
> +static int essiv_skcipher_encrypt(struct skcipher_request *req)
> +{
> + struct essiv_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
> +
> + essiv_skcipher_prepare_subreq(req);
> + return crypto_skcipher_encrypt(&rctx->blockcipher_req);
> +}
> +
> +static int essiv_aead_encrypt(struct aead_request *req)
> +{
> + struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
> + int err;
> +
> + err = essiv_aead_prepare_subreq(req);
> + if (err)
> + return err;
> + return crypto_aead_encrypt(&rctx->aead_req);
> +}
> +
> +static int essiv_skcipher_decrypt(struct skcipher_request *req)
> +{
> + struct essiv_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
> + return crypto_skcipher_decrypt(&rctx->blockcipher_req);
> +}
> +
> +static int essiv_aead_decrypt(struct aead_request *req)
> +{
> + struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
> + int err;
> +
> + err = essiv_aead_prepare_subreq(req);
> + if (err)
> + return err;
> +
> + essiv_aead_prepare_subreq(req);
> + return crypto_aead_decrypt(&rctx->aead_req);
> +}
> +
> +static int essiv_init_tfm(struct essiv_instance_ctx *ictx,
> + struct essiv_tfm_ctx *tctx)
> +{
> + struct crypto_cipher *essiv_cipher;
> + struct crypto_shash *hash;
> + int err;
> +
> + essiv_cipher = crypto_spawn_cipher(&ictx->essiv_cipher_spawn);
> + if (IS_ERR(essiv_cipher))
> + return PTR_ERR(essiv_cipher);
> +
> + hash = crypto_spawn_shash(&ictx->hash_spawn);
> + if (IS_ERR(hash)) {
> + err = PTR_ERR(hash);
> + goto err_free_essiv_cipher;
> + }
> +
> + tctx->essiv_cipher = essiv_cipher;
> + tctx->hash = hash;
> +
> + return 0;
> +
> +err_free_essiv_cipher:
> + crypto_free_cipher(essiv_cipher);
> + return err;
> +}
> +
> +static int essiv_skcipher_init_tfm(struct crypto_skcipher *tfm)
> +{
> + struct skcipher_instance *inst = skcipher_alg_instance(tfm);
> + struct essiv_instance_ctx *ictx = skcipher_instance_ctx(inst);
> + struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
> + struct crypto_skcipher *blockcipher;
> + unsigned int subreq_size;
> + int err;
> +
> + BUILD_BUG_ON(offsetofend(struct essiv_skcipher_request_ctx,
> + blockcipher_req) !=
> + sizeof(struct essiv_skcipher_request_ctx));
> +
> + blockcipher = crypto_spawn_skcipher(&ictx->u.blockcipher_spawn);
> + if (IS_ERR(blockcipher))
> + return PTR_ERR(blockcipher);
> +
> + subreq_size = FIELD_SIZEOF(struct essiv_skcipher_request_ctx,
> + blockcipher_req) +
> + crypto_skcipher_reqsize(blockcipher);
> +
> + crypto_skcipher_set_reqsize(tfm, offsetof(struct essiv_skcipher_request_ctx,
> + blockcipher_req) + subreq_size);
> +
> + err = essiv_init_tfm(ictx, tctx);
> + if (err)
> + crypto_free_skcipher(blockcipher);
> +
> + tctx->u.blockcipher = blockcipher;
> + return err;
> +}
> +
> +static int essiv_aead_init_tfm(struct crypto_aead *tfm)
> +{
> + struct aead_instance *inst = aead_alg_instance(tfm);
> + struct essiv_instance_ctx *ictx = aead_instance_ctx(inst);
> + struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
> + struct crypto_aead *aead;
> + unsigned int subreq_size;
> + int err;
> +
> + BUILD_BUG_ON(offsetofend(struct essiv_aead_request_ctx, aead_req) !=
> + sizeof(struct essiv_aead_request_ctx));
> +
> + aead = crypto_spawn_aead(&ictx->u.aead_spawn);
> + if (IS_ERR(aead))
> + return PTR_ERR(aead);
> +
> + subreq_size = FIELD_SIZEOF(struct essiv_aead_request_ctx, aead_req) +
> + crypto_aead_reqsize(aead);
> +
> + crypto_aead_set_reqsize(tfm, offsetof(struct essiv_aead_request_ctx,
> + aead_req) + subreq_size);
> +
> + err = essiv_init_tfm(ictx, tctx);
> + if (err)
> + crypto_free_aead(aead);
> +
> + tctx->u.aead = aead;
> + return err;
> +}
> +
> +static void essiv_skcipher_exit_tfm(struct crypto_skcipher *tfm)
> +{
> + struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
> +
> + crypto_free_skcipher(tctx->u.blockcipher);
> + crypto_free_cipher(tctx->essiv_cipher);
> + crypto_free_shash(tctx->hash);
> +}
> +
> +static void essiv_aead_exit_tfm(struct crypto_aead *tfm)
> +{
> + struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
> +
> + crypto_free_aead(tctx->u.aead);
> + crypto_free_cipher(tctx->essiv_cipher);
> + crypto_free_shash(tctx->hash);
> +}
> +
> +static void essiv_skcipher_free_instance(struct skcipher_instance *inst)
> +{
> + struct essiv_instance_ctx *ictx = skcipher_instance_ctx(inst);
> +
> + crypto_drop_skcipher(&ictx->u.blockcipher_spawn);
> + crypto_drop_spawn(&ictx->essiv_cipher_spawn);
> + crypto_drop_shash(&ictx->hash_spawn);
> + kfree(inst);
> +}
> +
> +static void essiv_aead_free_instance(struct aead_instance *inst)
> +{
> + struct essiv_instance_ctx *ictx = aead_instance_ctx(inst);
> +
> + crypto_drop_aead(&ictx->u.aead_spawn);
> + crypto_drop_spawn(&ictx->essiv_cipher_spawn);
> + crypto_drop_shash(&ictx->hash_spawn);
> + kfree(inst);
> +}
> +
> +static bool essiv_supported_algorithms(struct crypto_alg *essiv_cipher_alg,
> + struct shash_alg *hash_alg,
> + int ivsize)
> +{
> + if (hash_alg->digestsize < essiv_cipher_alg->cra_cipher.cia_min_keysize ||
> + hash_alg->digestsize > essiv_cipher_alg->cra_cipher.cia_max_keysize)
> + return false;
> +
> + if (ivsize != essiv_cipher_alg->cra_blocksize)
> + return false;
> +
> + if (ivsize > MAX_INNER_IV_SIZE)
> + return false;
> +
> + return true;
> +}
> +
> +static int essiv_create(struct crypto_template *tmpl, struct rtattr **tb)
> +{
> + struct crypto_attr_type *algt;
> + const char *blockcipher_name;
> + const char *essiv_cipher_name;
> + const char *shash_name;
> + struct skcipher_instance *skcipher_inst = NULL;
> + struct aead_instance *aead_inst = NULL;
> + struct crypto_instance *inst;
> + struct crypto_alg *base, *block_base;
> + struct essiv_instance_ctx *ictx;
> + struct skcipher_alg *blockcipher_alg = NULL;
> + struct aead_alg *aead_alg = NULL;
> + struct crypto_alg *essiv_cipher_alg;
> + struct crypto_alg *_hash_alg;
> + struct shash_alg *hash_alg;
> + int ivsize;
> + u32 type;
> + int err;
> +
> + algt = crypto_get_attr_type(tb);
> + if (IS_ERR(algt))
> + return PTR_ERR(algt);
> +
> + blockcipher_name = crypto_attr_alg_name(tb[1]);
> + if (IS_ERR(blockcipher_name))
> + return PTR_ERR(blockcipher_name);
> +
> + essiv_cipher_name = crypto_attr_alg_name(tb[2]);
> + if (IS_ERR(essiv_cipher_name))
> + return PTR_ERR(essiv_cipher_name);
> +
> + shash_name = crypto_attr_alg_name(tb[3]);
> + if (IS_ERR(shash_name))
> + return PTR_ERR(shash_name);
> +
> + type = algt->type & algt->mask;
> +
> + switch (type) {
> + case CRYPTO_ALG_TYPE_BLKCIPHER:
> + skcipher_inst = kzalloc(sizeof(*skcipher_inst) +
> + sizeof(*ictx), GFP_KERNEL);
> + if (!skcipher_inst)
> + return -ENOMEM;
> + inst = skcipher_crypto_instance(skcipher_inst);
> + base = &skcipher_inst->alg.base;
> + ictx = crypto_instance_ctx(inst);
> +
> + /* Block cipher, e.g. "cbc(aes)" */
> + crypto_set_skcipher_spawn(&ictx->u.blockcipher_spawn, inst);
> + err = crypto_grab_skcipher(&ictx->u.blockcipher_spawn,
> + blockcipher_name, 0,
> + crypto_requires_sync(algt->type,
> + algt->mask));
> + if (err)
> + goto out_free_inst;
> + blockcipher_alg = crypto_spawn_skcipher_alg(&ictx->u.blockcipher_spawn);
> + block_base = &blockcipher_alg->base;
> + ivsize = blockcipher_alg->ivsize;
> + break;
> +
> + case CRYPTO_ALG_TYPE_AEAD:
> + aead_inst = kzalloc(sizeof(*aead_inst) +
> + sizeof(*ictx), GFP_KERNEL);
> + if (!aead_inst)
> + return -ENOMEM;
> + inst = aead_crypto_instance(aead_inst);
> + base = &aead_inst->alg.base;
> + ictx = crypto_instance_ctx(inst);
> +
> + /* AEAD cipher, e.g. "authenc(hmac(sha256),cbc(aes))" */
> + crypto_set_aead_spawn(&ictx->u.aead_spawn, inst);
> + err = crypto_grab_aead(&ictx->u.aead_spawn,
> + blockcipher_name, 0,
> + crypto_requires_sync(algt->type,
> + algt->mask));
> + if (err)
> + goto out_free_inst;
> + aead_alg = crypto_spawn_aead_alg(&ictx->u.aead_spawn);
> + block_base = &aead_alg->base;
> + ivsize = aead_alg->ivsize;
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> +
> + /* Block cipher, e.g. "aes" */
> + crypto_set_spawn(&ictx->essiv_cipher_spawn, inst);
> + err = crypto_grab_spawn(&ictx->essiv_cipher_spawn, essiv_cipher_name,
> + CRYPTO_ALG_TYPE_CIPHER, CRYPTO_ALG_TYPE_MASK);
> + if (err)
> + goto out_drop_blockcipher;
> + essiv_cipher_alg = ictx->essiv_cipher_spawn.alg;
> +
> + /* Synchronous hash, e.g., "sha256" */
> + _hash_alg = crypto_alg_mod_lookup(shash_name,
> + CRYPTO_ALG_TYPE_SHASH,
> + CRYPTO_ALG_TYPE_MASK);
> + if (IS_ERR(_hash_alg)) {
> + err = PTR_ERR(_hash_alg);
> + goto out_drop_essiv_cipher;
> + }
> + hash_alg = __crypto_shash_alg(_hash_alg);
> + err = crypto_init_shash_spawn(&ictx->hash_spawn, hash_alg, inst);
> + if (err)
> + goto out_put_hash;
> +
> + /* Check the set of algorithms */
> + if (!essiv_supported_algorithms(essiv_cipher_alg, hash_alg, ivsize)) {
> + pr_warn("Unsupported essiv instantiation: (%s,%s,%s)\n",
> + block_base->cra_name,
> + essiv_cipher_alg->cra_name,
> + hash_alg->base.cra_name);
> + err = -EINVAL;
> + goto out_drop_hash;
> + }
> +
> + /* Instance fields */
> +
> + err = -ENAMETOOLONG;
> + if (snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME,
> + "essiv(%s,%s,%s)", block_base->cra_name,
> + essiv_cipher_alg->cra_name,
> + hash_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
> + goto out_drop_hash;
> + if (snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME,
> + "essiv(%s,%s,%s)",
> + block_base->cra_driver_name,
> + essiv_cipher_alg->cra_driver_name,
> + hash_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
> + goto out_drop_hash;
> +
> + base->cra_flags = block_base->cra_flags & CRYPTO_ALG_ASYNC;
> + base->cra_blocksize = block_base->cra_blocksize;
> + base->cra_ctxsize = sizeof(struct essiv_tfm_ctx);
> + base->cra_alignmask = block_base->cra_alignmask;
> + base->cra_priority = block_base->cra_priority;
> +
> + if (type == CRYPTO_ALG_TYPE_BLKCIPHER) {
> + skcipher_inst->alg.setkey = essiv_skcipher_setkey;
> + skcipher_inst->alg.encrypt = essiv_skcipher_encrypt;
> + skcipher_inst->alg.decrypt = essiv_skcipher_decrypt;
> + skcipher_inst->alg.init = essiv_skcipher_init_tfm;
> + skcipher_inst->alg.exit = essiv_skcipher_exit_tfm;
> +
> + skcipher_inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(blockcipher_alg);
> + skcipher_inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(blockcipher_alg);
> + skcipher_inst->alg.ivsize = ESSIV_IV_SIZE;
> + skcipher_inst->alg.chunksize = blockcipher_alg->chunksize;
> + skcipher_inst->alg.walksize = blockcipher_alg->walksize;
> +
> + skcipher_inst->free = essiv_skcipher_free_instance;
> +
> + err = skcipher_register_instance(tmpl, skcipher_inst);
> + } else {
> + aead_inst->alg.setkey = essiv_aead_setkey;
> + aead_inst->alg.setauthsize = essiv_aead_setauthsize;
> + aead_inst->alg.encrypt = essiv_aead_encrypt;
> + aead_inst->alg.decrypt = essiv_aead_decrypt;
> + aead_inst->alg.init = essiv_aead_init_tfm;
> + aead_inst->alg.exit = essiv_aead_exit_tfm;
> +
> + aead_inst->alg.ivsize = ESSIV_IV_SIZE;
> + aead_inst->alg.maxauthsize = aead_alg->maxauthsize;
> + aead_inst->alg.chunksize = aead_alg->chunksize;
> +
> + aead_inst->free = essiv_aead_free_instance;
> +
> + err = aead_register_instance(tmpl, aead_inst);
> + }
> +
> + if (err)
> + goto out_drop_hash;
> +
> + crypto_mod_put(_hash_alg);
> + return 0;
> +
> +out_drop_hash:
> + crypto_drop_shash(&ictx->hash_spawn);
> +out_put_hash:
> + crypto_mod_put(_hash_alg);
> +out_drop_essiv_cipher:
> + crypto_drop_spawn(&ictx->essiv_cipher_spawn);
> +out_drop_blockcipher:
> + if (type == CRYPTO_ALG_TYPE_BLKCIPHER) {
> + crypto_drop_skcipher(&ictx->u.blockcipher_spawn);
> + } else {
> + crypto_drop_aead(&ictx->u.aead_spawn);
> + }
> +out_free_inst:
> + kfree(skcipher_inst);
> + kfree(aead_inst);
> + return err;
> +}
> +
> +/* essiv(blockcipher_name, essiv_cipher_name, shash_name) */
> +static struct crypto_template essiv_tmpl = {
> + .name = "essiv",
> + .create = essiv_create,
> + .module = THIS_MODULE,
> +};
> +
> +static int __init essiv_module_init(void)
> +{
> + return crypto_register_template(&essiv_tmpl);
> +}
> +
> +static void __exit essiv_module_exit(void)
> +{
> + crypto_unregister_template(&essiv_tmpl);
> +}
> +
> +subsys_initcall(essiv_module_init);
> +module_exit(essiv_module_exit);
> +
> +MODULE_DESCRIPTION("ESSIV skcipher/aead wrapper for block encryption");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS_CRYPTO("essiv");
> --
> 2.17.1
>
