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-rw-r--r--crypto/Kconfig28
-rw-r--r--crypto/Makefile1
-rw-r--r--crypto/essiv.c663
3 files changed, 692 insertions, 0 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig
index e801450bcb1c..1e8390d32b6d 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -568,6 +568,34 @@ config CRYPTO_ADIANTUM
If unsure, say N.
+config CRYPTO_ESSIV
+ tristate "ESSIV support for block encryption"
+ select CRYPTO_AUTHENC
+ help
+ Encrypted salt-sector initialization vector (ESSIV) is an IV
+ generation method that is used in some cases by fscrypt and/or
+ dm-crypt. It uses the hash of the block encryption key as the
+ symmetric key for a block encryption pass applied to the input
+ IV, making low entropy IV sources more suitable for block
+ encryption.
+
+ This driver implements a crypto API template that can be
+ instantiated either as a skcipher or as a aead (depending on the
+ type of the first template argument), and which defers encryption
+ and decryption requests to the encapsulated cipher after applying
+ ESSIV to the input IV. Note that in the aead case, it is assumed
+ that the keys are presented in the same format used by the authenc
+ template, and that the IV appears at the end of the authenticated
+ associated data (AAD) region (which is how dm-crypt uses it.)
+
+ Note that the use of ESSIV is not recommended for new deployments,
+ and so this only needs to be enabled when interoperability with
+ existing encrypted volumes of filesystems is required, or when
+ building for a particular system that requires it (e.g., when
+ the SoC in question has accelerated CBC but not XTS, making CBC
+ combined with ESSIV the only feasible mode for h/w accelerated
+ block encryption)
+
comment "Hash modes"
config CRYPTO_CMAC
diff --git a/crypto/Makefile b/crypto/Makefile
index 9479e1a45d8c..157cb0a324df 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -147,6 +147,7 @@ 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..a8befc8fb06e
--- /dev/null
+++ b/crypto/essiv.c
@@ -0,0 +1,663 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ESSIV skcipher and aead template for block encryption
+ *
+ * This template encapsulates the ESSIV IV generation algorithm used by
+ * dm-crypt and fscrypt, which converts the initial vector for the skcipher
+ * used for block encryption, by encrypting it using the hash of the
+ * skcipher key as encryption key. Usually, the input IV is a 64-bit sector
+ * number in LE representation zero-padded to the size of the IV, but this
+ * is not assumed by this driver.
+ *
+ * The typical use of this template is to instantiate the skcipher
+ * 'essiv(cbc(aes),sha256)', which is the only instantiation used by
+ * fscrypt, and the most relevant one for dm-crypt. However, dm-crypt
+ * also permits ESSIV to be used in combination with the authenc template,
+ * e.g., 'essiv(authenc(hmac(sha256),cbc(aes)),sha256)', in which case
+ * we need to instantiate an aead that accepts the same special key format
+ * as the authenc template, and deals with the way the encrypted IV is
+ * embedded into the AAD area of the aead request. This means the AEAD
+ * flavor produced by this template is tightly coupled to the way dm-crypt
+ * happens to use it.
+ *
+ * Copyright (c) 2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
+ *
+ * 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"
+
+struct essiv_instance_ctx {
+ union {
+ struct crypto_skcipher_spawn skcipher_spawn;
+ struct crypto_aead_spawn aead_spawn;
+ } u;
+ char essiv_cipher_name[CRYPTO_MAX_ALG_NAME];
+ char shash_driver_name[CRYPTO_MAX_ALG_NAME];
+};
+
+struct essiv_tfm_ctx {
+ union {
+ struct crypto_skcipher *skcipher;
+ struct crypto_aead *aead;
+ } u;
+ struct crypto_cipher *essiv_cipher;
+ struct crypto_shash *hash;
+ int ivoffset;
+};
+
+struct essiv_aead_request_ctx {
+ struct scatterlist sg[4];
+ u8 *assoc;
+ struct aead_request aead_req;
+};
+
+static int essiv_skcipher_setkey(struct crypto_skcipher *tfm,
+ const u8 *key, unsigned int keylen)
+{
+ struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
+ SHASH_DESC_ON_STACK(desc, tctx->hash);
+ u8 salt[HASH_MAX_DIGESTSIZE];
+ int err;
+
+ crypto_skcipher_clear_flags(tctx->u.skcipher, CRYPTO_TFM_REQ_MASK);
+ crypto_skcipher_set_flags(tctx->u.skcipher,
+ crypto_skcipher_get_flags(tfm) &
+ CRYPTO_TFM_REQ_MASK);
+ err = crypto_skcipher_setkey(tctx->u.skcipher, key, keylen);
+ crypto_skcipher_set_flags(tfm,
+ crypto_skcipher_get_flags(tctx->u.skcipher) &
+ CRYPTO_TFM_RES_MASK);
+ if (err)
+ return err;
+
+ desc->tfm = tctx->hash;
+ err = crypto_shash_digest(desc, key, keylen, salt);
+ if (err)
+ return err;
+
+ crypto_cipher_clear_flags(tctx->essiv_cipher, CRYPTO_TFM_REQ_MASK);
+ crypto_cipher_set_flags(tctx->essiv_cipher,
+ crypto_skcipher_get_flags(tfm) &
+ CRYPTO_TFM_REQ_MASK);
+ err = crypto_cipher_setkey(tctx->essiv_cipher, salt,
+ crypto_shash_digestsize(tctx->hash));
+ crypto_skcipher_set_flags(tfm,
+ crypto_cipher_get_flags(tctx->essiv_cipher) &
+ CRYPTO_TFM_RES_MASK);
+
+ 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;
+ u8 salt[HASH_MAX_DIGESTSIZE];
+ 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;
+ }
+
+ desc->tfm = tctx->hash;
+ err = crypto_shash_init(desc) ?:
+ crypto_shash_update(desc, keys.enckey, keys.enckeylen) ?:
+ crypto_shash_finup(desc, keys.authkey, keys.authkeylen, salt);
+ if (err)
+ return err;
+
+ 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,
+ crypto_shash_digestsize(tctx->hash));
+ crypto_aead_set_flags(tfm, crypto_cipher_get_flags(tctx->essiv_cipher) &
+ CRYPTO_TFM_RES_MASK);
+
+ 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 int essiv_skcipher_crypt(struct skcipher_request *req, bool enc)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ const struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
+ struct skcipher_request *subreq = skcipher_request_ctx(req);
+
+ crypto_cipher_encrypt_one(tctx->essiv_cipher, req->iv, req->iv);
+
+ skcipher_request_set_tfm(subreq, tctx->u.skcipher);
+ skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
+ req->iv);
+ skcipher_request_set_callback(subreq, skcipher_request_flags(req),
+ essiv_skcipher_done, req);
+
+ return enc ? crypto_skcipher_encrypt(subreq) :
+ crypto_skcipher_decrypt(subreq);
+}
+
+static int essiv_skcipher_encrypt(struct skcipher_request *req)
+{
+ return essiv_skcipher_crypt(req, true);
+}
+
+static int essiv_skcipher_decrypt(struct skcipher_request *req)
+{
+ return essiv_skcipher_crypt(req, false);
+}
+
+static void essiv_aead_done(struct crypto_async_request *areq, int err)
+{
+ struct aead_request *req = areq->data;
+ struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
+
+ if (rctx->assoc)
+ kfree(rctx->assoc);
+ aead_request_complete(req, err);
+}
+
+static int essiv_aead_crypt(struct aead_request *req, bool enc)
+{
+ 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);
+ struct aead_request *subreq = &rctx->aead_req;
+ struct scatterlist *src = req->src;
+ int err;
+
+ crypto_cipher_encrypt_one(tctx->essiv_cipher, req->iv, req->iv);
+
+ /*
+ * dm-crypt embeds the sector number and the IV in the AAD region, so
+ * we have to copy the converted IV into the right scatterlist before
+ * we pass it on.
+ */
+ rctx->assoc = NULL;
+ if (req->src == req->dst || !enc) {
+ scatterwalk_map_and_copy(req->iv, req->dst,
+ req->assoclen - crypto_aead_ivsize(tfm),
+ crypto_aead_ivsize(tfm), 1);
+ } else {
+ u8 *iv = (u8 *)aead_request_ctx(req) + tctx->ivoffset;
+ int ivsize = crypto_aead_ivsize(tfm);
+ int ssize = req->assoclen - ivsize;
+ struct scatterlist *sg;
+ int nents;
+
+ if (ssize < 0)
+ return -EINVAL;
+
+ nents = sg_nents_for_len(req->src, ssize);
+ if (nents < 0)
+ return -EINVAL;
+
+ memcpy(iv, req->iv, ivsize);
+ sg_init_table(rctx->sg, 4);
+
+ if (unlikely(nents > 1)) {
+ /*
+ * This is a case that rarely occurs in practice, but
+ * for correctness, we have to deal with it nonetheless.
+ */
+ rctx->assoc = kmalloc(ssize, GFP_ATOMIC);
+ if (!rctx->assoc)
+ return -ENOMEM;
+
+ scatterwalk_map_and_copy(rctx->assoc, req->src, 0,
+ ssize, 0);
+ sg_set_buf(rctx->sg, rctx->assoc, ssize);
+ } else {
+ sg_set_page(rctx->sg, sg_page(req->src), ssize,
+ req->src->offset);
+ }
+
+ sg_set_buf(rctx->sg + 1, iv, ivsize);
+ sg = scatterwalk_ffwd(rctx->sg + 2, req->src, req->assoclen);
+ if (sg != rctx->sg + 2)
+ sg_chain(rctx->sg, 3, sg);
+
+ src = rctx->sg;
+ }
+
+ aead_request_set_tfm(subreq, tctx->u.aead);
+ aead_request_set_ad(subreq, req->assoclen);
+ aead_request_set_callback(subreq, aead_request_flags(req),
+ essiv_aead_done, req);
+ aead_request_set_crypt(subreq, src, req->dst, req->cryptlen, req->iv);
+
+ err = enc ? crypto_aead_encrypt(subreq) :
+ crypto_aead_decrypt(subreq);
+
+ if (rctx->assoc && err != -EINPROGRESS)
+ kfree(rctx->assoc);
+ return err;
+}
+
+static int essiv_aead_encrypt(struct aead_request *req)
+{
+ return essiv_aead_crypt(req, true);
+}
+
+static int essiv_aead_decrypt(struct aead_request *req)
+{
+ return essiv_aead_crypt(req, false);
+}
+
+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_alloc_cipher(ictx->essiv_cipher_name, 0, 0);
+ if (IS_ERR(essiv_cipher))
+ return PTR_ERR(essiv_cipher);
+
+ hash = crypto_alloc_shash(ictx->shash_driver_name, 0, 0);
+ 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 *skcipher;
+ int err;
+
+ skcipher = crypto_spawn_skcipher(&ictx->u.skcipher_spawn);
+ if (IS_ERR(skcipher))
+ return PTR_ERR(skcipher);
+
+ crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
+ crypto_skcipher_reqsize(skcipher));
+
+ err = essiv_init_tfm(ictx, tctx);
+ if (err) {
+ crypto_free_skcipher(skcipher);
+ return err;
+ }
+
+ tctx->u.skcipher = skcipher;
+ return 0;
+}
+
+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);
+
+ tctx->ivoffset = offsetof(struct essiv_aead_request_ctx, aead_req) +
+ subreq_size;
+ crypto_aead_set_reqsize(tfm, tctx->ivoffset + crypto_aead_ivsize(aead));
+
+ err = essiv_init_tfm(ictx, tctx);
+ if (err) {
+ crypto_free_aead(aead);
+ return err;
+ }
+
+ tctx->u.aead = aead;
+ return 0;
+}
+
+static void essiv_skcipher_exit_tfm(struct crypto_skcipher *tfm)
+{
+ struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
+
+ crypto_free_skcipher(tctx->u.skcipher);
+ 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.skcipher_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);
+ kfree(inst);
+}
+
+static bool parse_cipher_name(char *essiv_cipher_name, const char *cra_name)
+{
+ const char *p, *q;
+ int len;
+
+ /* find the last opening parens */
+ p = strrchr(cra_name, '(');
+ if (!p++)
+ return false;
+
+ /* find the first closing parens in the tail of the string */
+ q = strchr(p, ')');
+ if (!q)
+ return false;
+
+ len = q - p;
+ if (len >= CRYPTO_MAX_ALG_NAME)
+ return false;
+
+ memcpy(essiv_cipher_name, p, len);
+ essiv_cipher_name[len] = '\0';
+ return true;
+}
+
+static bool essiv_supported_algorithms(const char *essiv_cipher_name,
+ struct shash_alg *hash_alg,
+ int ivsize)
+{
+ struct crypto_alg *alg;
+ bool ret = false;
+
+ alg = crypto_alg_mod_lookup(essiv_cipher_name,
+ CRYPTO_ALG_TYPE_CIPHER,
+ CRYPTO_ALG_TYPE_MASK);
+ if (IS_ERR(alg))
+ return false;
+
+ if (hash_alg->digestsize < alg->cra_cipher.cia_min_keysize ||
+ hash_alg->digestsize > alg->cra_cipher.cia_max_keysize)
+ goto out;
+
+ if (ivsize != alg->cra_blocksize)
+ goto out;
+
+ if (crypto_shash_alg_has_setkey(hash_alg))
+ goto out;
+
+ ret = true;
+
+out:
+ crypto_mod_put(alg);
+ return ret;
+}
+
+static int essiv_create(struct crypto_template *tmpl, struct rtattr **tb)
+{
+ struct crypto_attr_type *algt;
+ const char *inner_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 *skcipher_alg = NULL;
+ struct aead_alg *aead_alg = NULL;
+ 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);
+
+ inner_cipher_name = crypto_attr_alg_name(tb[1]);
+ if (IS_ERR(inner_cipher_name))
+ return PTR_ERR(inner_cipher_name);
+
+ shash_name = crypto_attr_alg_name(tb[2]);
+ 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);
+
+ /* Symmetric cipher, e.g., "cbc(aes)" */
+ crypto_set_skcipher_spawn(&ictx->u.skcipher_spawn, inst);
+ err = crypto_grab_skcipher(&ictx->u.skcipher_spawn,
+ inner_cipher_name, 0,
+ crypto_requires_sync(algt->type,
+ algt->mask));
+ if (err)
+ goto out_free_inst;
+ skcipher_alg = crypto_spawn_skcipher_alg(&ictx->u.skcipher_spawn);
+ block_base = &skcipher_alg->base;
+ ivsize = crypto_skcipher_alg_ivsize(skcipher_alg);
+ 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,
+ inner_cipher_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;
+ if (!strstarts(block_base->cra_name, "authenc(")) {
+ pr_warn("Only authenc() type AEADs are supported by ESSIV\n");
+ err = -EINVAL;
+ goto out_drop_skcipher;
+ }
+ ivsize = aead_alg->ivsize;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (!parse_cipher_name(ictx->essiv_cipher_name, block_base->cra_name)) {
+ pr_warn("Failed to parse ESSIV cipher name from skcipher cra_name\n");
+ err = -EINVAL;
+ goto out_drop_skcipher;
+ }
+
+ /* 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_skcipher;
+ }
+ hash_alg = __crypto_shash_alg(_hash_alg);
+
+ /* Check the set of algorithms */
+ if (!essiv_supported_algorithms(ictx->essiv_cipher_name, hash_alg,
+ ivsize)) {
+ pr_warn("Unsupported essiv instantiation: essiv(%s,%s)\n",
+ block_base->cra_name, hash_alg->base.cra_name);
+ err = -EINVAL;
+ goto out_free_hash;
+ }
+
+ /* record the driver name so we can instantiate this exact algo later */
+ strlcpy(ictx->shash_driver_name, hash_alg->base.cra_driver_name,
+ CRYPTO_MAX_ALG_NAME);
+
+ /* Instance fields */
+
+ err = -ENAMETOOLONG;
+ if (snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME,
+ "essiv(%s,%s)", block_base->cra_name,
+ hash_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
+ goto out_free_hash;
+ if (snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME,
+ "essiv(%s,%s)", block_base->cra_driver_name,
+ hash_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
+ goto out_free_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(skcipher_alg);
+ skcipher_inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(skcipher_alg);
+ skcipher_inst->alg.ivsize = ivsize;
+ skcipher_inst->alg.chunksize = crypto_skcipher_alg_chunksize(skcipher_alg);
+ skcipher_inst->alg.walksize = crypto_skcipher_alg_walksize(skcipher_alg);
+
+ 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 = ivsize;
+ aead_inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(aead_alg);
+ aead_inst->alg.chunksize = crypto_aead_alg_chunksize(aead_alg);
+
+ aead_inst->free = essiv_aead_free_instance;
+
+ err = aead_register_instance(tmpl, aead_inst);
+ }
+
+ if (err)
+ goto out_free_hash;
+
+ crypto_mod_put(_hash_alg);
+ return 0;
+
+out_free_hash:
+ crypto_mod_put(_hash_alg);
+out_drop_skcipher:
+ if (type == CRYPTO_ALG_TYPE_BLKCIPHER)
+ crypto_drop_skcipher(&ictx->u.skcipher_spawn);
+ else
+ crypto_drop_aead(&ictx->u.aead_spawn);
+out_free_inst:
+ kfree(skcipher_inst);
+ kfree(aead_inst);
+ return err;
+}
+
+/* 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");