[linux-2.6-block.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 <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)
{
	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);

	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),
			       crypto_attr_alg_name(tb[1]), 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_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_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_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 <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
	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 HX	41	struct aead_instance aead_geniv_alloc(struct crypto_template tmpl,
	42	struct rtattr **tb, u32 type, u32 mask)
	43	{
20cc01ba HX	44	struct crypto_aead_spawn *spawn;
	45	struct crypto_attr_type *algt;
	46	struct aead_instance *inst;
	47	struct aead_alg *alg;
	48	unsigned int ivsize;
	49	unsigned int maxauthsize;
	50	int err;
	51
	52	algt = crypto_get_attr_type(tb);
	53	if (IS_ERR(algt))
	54	return ERR_CAST(algt);
	55
	56	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
	57	return ERR_PTR(-EINVAL);
	58
20cc01ba HX	59	inst = kzalloc(sizeof(inst) + sizeof(spawn), GFP_KERNEL);
	60	if (!inst)
	61	return ERR_PTR(-ENOMEM);
	62
	63	spawn = aead_instance_ctx(inst);
	64
	65	/* Ignore async algorithms if necessary. */
	66	mask \|= crypto_requires_sync(algt->type, algt->mask);
	67
cd900f0c	68	err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
376ffe1a	69	crypto_attr_alg_name(tb[1]), type, mask);
20cc01ba HX	70	if (err)
	71	goto err_free_inst;
	72
	73	alg = crypto_spawn_aead_alg(spawn);
	74
	75	ivsize = crypto_aead_alg_ivsize(alg);
	76	maxauthsize = crypto_aead_alg_maxauthsize(alg);
	77
	78	err = -EINVAL;
	79	if (ivsize < sizeof(u64))
376ffe1a	80	goto err_free_inst;
20cc01ba HX	81
	82	err = -ENAMETOOLONG;
	83	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
	84	"%s(%s)", tmpl->name, alg->base.cra_name) >=
	85	CRYPTO_MAX_ALG_NAME)
376ffe1a	86	goto err_free_inst;
20cc01ba HX	87	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
	88	"%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
	89	CRYPTO_MAX_ALG_NAME)
376ffe1a	90	goto err_free_inst;
20cc01ba HX	91
	92	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
	93	inst->alg.base.cra_priority = alg->base.cra_priority;
	94	inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
	95	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
	96	inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
	97
	98	inst->alg.setkey = aead_geniv_setkey;
	99	inst->alg.setauthsize = aead_geniv_setauthsize;
	100
	101	inst->alg.ivsize = ivsize;
	102	inst->alg.maxauthsize = maxauthsize;
	103
0f8f6d86 EB	104	inst->free = aead_geniv_free;
0f8f6d86 EB	105
20cc01ba HX	106	out:
	107	return inst;
	108
20cc01ba	109	err_free_inst:
376ffe1a	110	aead_geniv_free(inst);
20cc01ba HX	111	inst = ERR_PTR(err);
	112	goto out;
	113	}
	114	EXPORT_SYMBOL_GPL(aead_geniv_alloc);
	115
20cc01ba HX	116	int aead_init_geniv(struct crypto_aead *aead)
	117	{
	118	struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
	119	struct aead_instance *inst = aead_alg_instance(aead);
	120	struct crypto_aead *child;
	121	int err;
	122
	123	spin_lock_init(&ctx->lock);
	124
	125	err = crypto_get_default_rng();
	126	if (err)
	127	goto out;
	128
	129	err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
	130	crypto_aead_ivsize(aead));
	131	crypto_put_default_rng();
	132	if (err)
	133	goto out;
	134
	135	ctx->sknull = crypto_get_default_null_skcipher();
	136	err = PTR_ERR(ctx->sknull);
	137	if (IS_ERR(ctx->sknull))
	138	goto out;
	139
	140	child = crypto_spawn_aead(aead_instance_ctx(inst));
	141	err = PTR_ERR(child);
	142	if (IS_ERR(child))
	143	goto drop_null;
	144
	145	ctx->child = child;
	146	crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
	147	sizeof(struct aead_request));
	148
	149	err = 0;
	150
	151	out:
	152	return err;
	153
	154	drop_null:
	155	crypto_put_default_null_skcipher();
	156	goto out;
	157	}
	158	EXPORT_SYMBOL_GPL(aead_init_geniv);
	159
	160	void aead_exit_geniv(struct crypto_aead *tfm)
	161	{
	162	struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
	163
	164	crypto_free_aead(ctx->child);
	165	crypto_put_default_null_skcipher();
	166	}
	167	EXPORT_SYMBOL_GPL(aead_exit_geniv);
	168
	169	MODULE_LICENSE("GPL");
	170	MODULE_DESCRIPTION("Shared IV generator code");