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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * geniv: Shared IV generator code4 *5 * This file provides common code to IV generators such as seqiv.6 *7 * Copyright (c) 2007-2019 Herbert Xu <herbert@gondor.apana.org.au>8 */9 10#include <crypto/internal/geniv.h>11#include <crypto/internal/rng.h>12#include <crypto/null.h>13#include <linux/err.h>14#include <linux/kernel.h>15#include <linux/module.h>16#include <linux/rtnetlink.h>17#include <linux/slab.h>18 19static int aead_geniv_setkey(struct crypto_aead *tfm,20 const u8 *key, unsigned int keylen)21{22 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);23 24 return crypto_aead_setkey(ctx->child, key, keylen);25}26 27static int aead_geniv_setauthsize(struct crypto_aead *tfm,28 unsigned int authsize)29{30 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);31 32 return crypto_aead_setauthsize(ctx->child, authsize);33}34 35static void aead_geniv_free(struct aead_instance *inst)36{37 crypto_drop_aead(aead_instance_ctx(inst));38 kfree(inst);39}40 41struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,42 struct rtattr **tb)43{44 struct crypto_aead_spawn *spawn;45 struct aead_instance *inst;46 struct aead_alg *alg;47 unsigned int ivsize;48 unsigned int maxauthsize;49 u32 mask;50 int err;51 52 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);53 if (err)54 return ERR_PTR(err);55 56 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);57 if (!inst)58 return ERR_PTR(-ENOMEM);59 60 spawn = aead_instance_ctx(inst);61 62 err = crypto_grab_aead(spawn, aead_crypto_instance(inst),63 crypto_attr_alg_name(tb[1]), 0, mask);64 if (err)65 goto err_free_inst;66 67 alg = crypto_spawn_aead_alg(spawn);68 69 ivsize = crypto_aead_alg_ivsize(alg);70 maxauthsize = crypto_aead_alg_maxauthsize(alg);71 72 err = -EINVAL;73 if (ivsize < sizeof(u64))74 goto err_free_inst;75 76 err = -ENAMETOOLONG;77 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,78 "%s(%s)", tmpl->name, alg->base.cra_name) >=79 CRYPTO_MAX_ALG_NAME)80 goto err_free_inst;81 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,82 "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=83 CRYPTO_MAX_ALG_NAME)84 goto err_free_inst;85 86 inst->alg.base.cra_priority = alg->base.cra_priority;87 inst->alg.base.cra_blocksize = alg->base.cra_blocksize;88 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;89 inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);90 91 inst->alg.setkey = aead_geniv_setkey;92 inst->alg.setauthsize = aead_geniv_setauthsize;93 94 inst->alg.ivsize = ivsize;95 inst->alg.maxauthsize = maxauthsize;96 97 inst->free = aead_geniv_free;98 99out:100 return inst;101 102err_free_inst:103 aead_geniv_free(inst);104 inst = ERR_PTR(err);105 goto out;106}107EXPORT_SYMBOL_GPL(aead_geniv_alloc);108 109int aead_init_geniv(struct crypto_aead *aead)110{111 struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);112 struct aead_instance *inst = aead_alg_instance(aead);113 struct crypto_aead *child;114 int err;115 116 spin_lock_init(&ctx->lock);117 118 err = crypto_get_default_rng();119 if (err)120 goto out;121 122 err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,123 crypto_aead_ivsize(aead));124 crypto_put_default_rng();125 if (err)126 goto out;127 128 ctx->sknull = crypto_get_default_null_skcipher();129 err = PTR_ERR(ctx->sknull);130 if (IS_ERR(ctx->sknull))131 goto out;132 133 child = crypto_spawn_aead(aead_instance_ctx(inst));134 err = PTR_ERR(child);135 if (IS_ERR(child))136 goto drop_null;137 138 ctx->child = child;139 crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +140 sizeof(struct aead_request));141 142 err = 0;143 144out:145 return err;146 147drop_null:148 crypto_put_default_null_skcipher();149 goto out;150}151EXPORT_SYMBOL_GPL(aead_init_geniv);152 153void aead_exit_geniv(struct crypto_aead *tfm)154{155 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);156 157 crypto_free_aead(ctx->child);158 crypto_put_default_null_skcipher();159}160EXPORT_SYMBOL_GPL(aead_exit_geniv);161 162MODULE_LICENSE("GPL");163MODULE_DESCRIPTION("Shared IV generator code");164