geniv.c
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// 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, u32 type, u32 mask)
{
const char *name;
struct crypto_aead_spawn *spawn;
struct crypto_attr_type *algt;
struct aead_instance *inst;
struct aead_alg *alg;
unsigned int ivsize;
unsigned int maxauthsize;
int err;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return ERR_CAST(algt);
if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
return ERR_PTR(-EINVAL);
name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(name))
return ERR_CAST(name);
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return ERR_PTR(-ENOMEM);
spawn = aead_instance_ctx(inst);
/* Ignore async algorithms if necessary. */
mask |= crypto_requires_sync(algt->type, algt->mask);
err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
name, type, 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_drop_alg;
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_drop_alg;
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_drop_alg;
inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
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_drop_alg:
crypto_drop_aead(spawn);
err_free_inst:
kfree(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");