// 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/cipher.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); 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); if (err) return err; err = crypto_shash_tfm_digest(tctx->hash, 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); return crypto_cipher_setkey(tctx->essiv_cipher, salt, crypto_shash_digestsize(tctx->hash));} 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); if (err) return err; if (crypto_authenc_extractkeys(&keys, key, keylen) != 0) 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); return crypto_cipher_setkey(tctx->essiv_cipher, salt, crypto_shash_digestsize(tctx->hash));} 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(void *data, int err){ struct skcipher_request *req = 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(void *data, int err){ struct aead_request *req = data; struct essiv_aead_request_ctx *rctx = aead_request_ctx(req); if (err == -EINPROGRESS) goto out; kfree(rctx->assoc); out: 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; int ivsize = crypto_aead_ivsize(tfm); int ssize = req->assoclen - ivsize; struct scatterlist *src = req->src; int err; if (ssize < 0) return -EINVAL; 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, ssize, ivsize, 1); } else { u8 *iv = (u8 *)aead_request_ctx(req) + tctx->ivoffset; struct scatterlist *sg; int nents; 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 && err != -EBUSY) 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 = sizeof_field(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; strscpy(essiv_cipher_name, p, len + 1); 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_needs_key(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 skcipher_alg_common *skcipher_alg = NULL; 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 aead_alg *aead_alg = NULL; struct crypto_alg *_hash_alg; struct shash_alg *hash_alg; int ivsize; u32 type; u32 mask; 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; mask = crypto_algt_inherited_mask(algt); switch (type) { case CRYPTO_ALG_TYPE_LSKCIPHER: 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)" */ err = crypto_grab_skcipher(&ictx->u.skcipher_spawn, inst, inner_cipher_name, 0, mask); if (err) goto out_free_inst; skcipher_alg = crypto_spawn_skcipher_alg_common( &ictx->u.skcipher_spawn); block_base = &skcipher_alg->base; ivsize = skcipher_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);Lines 1–500 of 648. Load more
// 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/cipher.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); 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); if (err) return err; err = crypto_shash_tfm_digest(tctx->hash, 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); return crypto_cipher_setkey(tctx->essiv_cipher, salt, crypto_shash_digestsize(tctx->hash)); } 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); if (err) return err; if (crypto_authenc_extractkeys(&keys, key, keylen) != 0) 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); return crypto_cipher_setkey(tctx->essiv_cipher, salt, crypto_shash_digestsize(tctx->hash)); } 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(void *data, int err) { struct skcipher_request *req = 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(void *data, int err) { struct aead_request *req = data; struct essiv_aead_request_ctx *rctx = aead_request_ctx(req); if (err == -EINPROGRESS) goto out; kfree(rctx->assoc); out: 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; int ivsize = crypto_aead_ivsize(tfm); int ssize = req->assoclen - ivsize; struct scatterlist *src = req->src; int err; if (ssize < 0) return -EINVAL; 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, ssize, ivsize, 1); } else { u8 *iv = (u8 *)aead_request_ctx(req) + tctx->ivoffset; struct scatterlist *sg; int nents; 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 && err != -EBUSY) 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 = sizeof_field(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; strscpy(essiv_cipher_name, p, len + 1); 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_needs_key(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 skcipher_alg_common *skcipher_alg = NULL; 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 aead_alg *aead_alg = NULL; struct crypto_alg *_hash_alg; struct shash_alg *hash_alg; int ivsize; u32 type; u32 mask; 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; mask = crypto_algt_inherited_mask(algt); switch (type) { case CRYPTO_ALG_TYPE_LSKCIPHER: 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)" */ err = crypto_grab_skcipher(&ictx->u.skcipher_spawn, inst, inner_cipher_name, 0, mask); if (err) goto out_free_inst; skcipher_alg = crypto_spawn_skcipher_alg_common( &ictx->u.skcipher_spawn); block_base = &skcipher_alg->base; ivsize = skcipher_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);