[linux.git] / crypto / geniv.c

// 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 <[email protected]>
 */

#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");
Commit	Line	Data
20cc01ba HX	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* geniv: Shared IV generator code
	4	*
	5	* This file provides common code to IV generators such as seqiv.
	6	*
	7	* Copyright (c) 2007-2019 Herbert Xu <[email protected]>
	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
	19	static 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
	27	static 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
0f8f6d86 EB	35	static void aead_geniv_free(struct aead_instance *inst)
	36	{
	37	crypto_drop_aead(aead_instance_ctx(inst));
	38	kfree(inst);
	39	}
	40
20cc01ba	41	struct aead_instance aead_geniv_alloc(struct crypto_template tmpl,
e72b48c5	42	struct rtattr **tb)
20cc01ba	43	{
20cc01ba	44	struct crypto_aead_spawn *spawn;
20cc01ba HX	45	struct aead_instance *inst;
	46	struct aead_alg *alg;
	47	unsigned int ivsize;
	48	unsigned int maxauthsize;
e72b48c5	49	u32 mask;
20cc01ba HX	50	int err;
20cc01ba HX	51
7bcb2c99 EB	52	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
	53	if (err)
	54	return ERR_PTR(err);
20cc01ba	55
20cc01ba HX	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
cd900f0c	62	err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
e72b48c5	63	crypto_attr_alg_name(tb[1]), 0, mask);
20cc01ba HX	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))
376ffe1a	74	goto err_free_inst;
20cc01ba HX	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)
376ffe1a	80	goto err_free_inst;
20cc01ba HX	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)
376ffe1a	84	goto err_free_inst;
20cc01ba	85
20cc01ba HX	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
0f8f6d86 EB	97	inst->free = aead_geniv_free;
0f8f6d86 EB	98
20cc01ba HX	99	out:
	100	return inst;
	101
20cc01ba	102	err_free_inst:
376ffe1a	103	aead_geniv_free(inst);
20cc01ba HX	104	inst = ERR_PTR(err);
	105	goto out;
	106	}
	107	EXPORT_SYMBOL_GPL(aead_geniv_alloc);
	108
20cc01ba HX	109	int 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
	144	out:
	145	return err;
	146
	147	drop_null:
	148	crypto_put_default_null_skcipher();
	149	goto out;
	150	}
	151	EXPORT_SYMBOL_GPL(aead_init_geniv);
	152
	153	void 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	}
	160	EXPORT_SYMBOL_GPL(aead_exit_geniv);
	161
	162	MODULE_LICENSE("GPL");
	163	MODULE_DESCRIPTION("Shared IV generator code");