// SPDX-License-Identifier: GPL-2.0-or-later /* * geniv: Shared IV generator code * * This file provides common code to IV generators such as seqiv. * * Copyright (c) 2007-2019 Herbert Xu <herbert@gondor.apana.org.au> */ #include <crypto/internal/geniv.h> #include <crypto/internal/rng.h> #include <crypto/null.h> #include <linux/err.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/rtnetlink.h> #include <linux/slab.h> static int aead_geniv_setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen) { struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm); return crypto_aead_setkey(ctx->child, key, keylen); } static int aead_geniv_setauthsize(struct crypto_aead *tfm, unsigned int authsize) { struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm); return crypto_aead_setauthsize(ctx->child, authsize); } static void aead_geniv_free(struct aead_instance *inst) { crypto_drop_aead(aead_instance_ctx(inst)); kfree(inst); } struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl, struct rtattr **tb) { struct crypto_aead_spawn *spawn; struct aead_instance *inst; struct aead_alg *alg; unsigned int ivsize; unsigned int maxauthsize; u32 mask; int err; err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); if (err) return ERR_PTR(err); inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); if (!inst) return ERR_PTR(-ENOMEM); spawn = aead_instance_ctx(inst); err = crypto_grab_aead(spawn, aead_crypto_instance(inst), crypto_attr_alg_name(tb[1]), 0, mask); if (err) goto err_free_inst; alg = crypto_spawn_aead_alg(spawn); ivsize = crypto_aead_alg_ivsize(alg); maxauthsize = crypto_aead_alg_maxauthsize(alg); err = -EINVAL; if (ivsize < sizeof(u64)) goto err_free_inst; err = -ENAMETOOLONG; if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", tmpl->name, alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME) goto err_free_inst; if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", tmpl->name, alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME) goto err_free_inst; inst->alg.base.cra_priority = alg->base.cra_priority; inst->alg.base.cra_blocksize = alg->base.cra_blocksize; inst->alg.base.cra_alignmask = alg->base.cra_alignmask; inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx); inst->alg.setkey = aead_geniv_setkey; inst->alg.setauthsize = aead_geniv_setauthsize; inst->alg.ivsize = ivsize; inst->alg.maxauthsize = maxauthsize; inst->free = aead_geniv_free; out: return inst; err_free_inst: aead_geniv_free(inst); inst = ERR_PTR(err); goto out; } EXPORT_SYMBOL_GPL(aead_geniv_alloc); int aead_init_geniv(struct crypto_aead *aead) { struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead); struct aead_instance *inst = aead_alg_instance(aead); struct crypto_aead *child; int err; spin_lock_init(&ctx->lock); err = crypto_get_default_rng(); if (err) goto out; err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt, crypto_aead_ivsize(aead)); crypto_put_default_rng(); if (err) goto out; ctx->sknull = crypto_get_default_null_skcipher(); err = PTR_ERR(ctx->sknull); if (IS_ERR(ctx->sknull)) goto out; child = crypto_spawn_aead(aead_instance_ctx(inst)); err = PTR_ERR(child); if (IS_ERR(child)) goto drop_null; ctx->child = child; crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) + sizeof(struct aead_request)); err = 0; out: return err; drop_null: crypto_put_default_null_skcipher(); goto out; } EXPORT_SYMBOL_GPL(aead_init_geniv); void aead_exit_geniv(struct crypto_aead *tfm) { struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm); crypto_free_aead(ctx->child); crypto_put_default_null_skcipher(); } EXPORT_SYMBOL_GPL(aead_exit_geniv); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Shared IV generator code");