[linux.git] / crypto / authencesn.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * authencesn.c - AEAD wrapper for IPsec with extended sequence numbers,
 *                 derived from authenc.c
 *
 * Copyright (C) 2010 secunet Security Networks AG
 * Copyright (C) 2010 Steffen Klassert <[email protected]>
 * Copyright (c) 2015 Herbert Xu <[email protected]>
 */

#include <crypto/internal/aead.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/skcipher.h>
#include <crypto/authenc.h>
#include <crypto/null.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

struct authenc_esn_instance_ctx {
	struct crypto_ahash_spawn auth;
	struct crypto_skcipher_spawn enc;
};

struct crypto_authenc_esn_ctx {
	unsigned int reqoff;
	struct crypto_ahash *auth;
	struct crypto_skcipher *enc;
	struct crypto_sync_skcipher *null;
};

struct authenc_esn_request_ctx {
	struct scatterlist src[2];
	struct scatterlist dst[2];
	char tail[];
};

static void authenc_esn_request_complete(struct aead_request *req, int err)
{
	if (err != -EINPROGRESS)
		aead_request_complete(req, err);
}

static int crypto_authenc_esn_setauthsize(struct crypto_aead *authenc_esn,
					  unsigned int authsize)
{
	if (authsize > 0 && authsize < 4)
		return -EINVAL;

	return 0;
}

static int crypto_authenc_esn_setkey(struct crypto_aead *authenc_esn, const u8 *key,
				     unsigned int keylen)
{
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
	struct crypto_ahash *auth = ctx->auth;
	struct crypto_skcipher *enc = ctx->enc;
	struct crypto_authenc_keys keys;
	int err = -EINVAL;

	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
		goto out;

	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc_esn) &
				     CRYPTO_TFM_REQ_MASK);
	err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
	if (err)
		goto out;

	crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
	crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc_esn) &
					 CRYPTO_TFM_REQ_MASK);
	err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
out:
	memzero_explicit(&keys, sizeof(keys));
	return err;
}

static int crypto_authenc_esn_genicv_tail(struct aead_request *req,
					  unsigned int flags)
{
	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
	struct crypto_ahash *auth = ctx->auth;
	u8 *hash = PTR_ALIGN((u8 *)areq_ctx->tail,
			     crypto_ahash_alignmask(auth) + 1);
	unsigned int authsize = crypto_aead_authsize(authenc_esn);
	unsigned int assoclen = req->assoclen;
	unsigned int cryptlen = req->cryptlen;
	struct scatterlist *dst = req->dst;
	u32 tmp[2];

	/* Move high-order bits of sequence number back. */
	scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
	scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);

	scatterwalk_map_and_copy(hash, dst, assoclen + cryptlen, authsize, 1);
	return 0;
}

static void authenc_esn_geniv_ahash_done(struct crypto_async_request *areq,
					 int err)
{
	struct aead_request *req = areq->data;

	err = err ?: crypto_authenc_esn_genicv_tail(req, 0);
	aead_request_complete(req, err);
}

static int crypto_authenc_esn_genicv(struct aead_request *req,
				     unsigned int flags)
{
	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
	struct crypto_ahash *auth = ctx->auth;
	u8 *hash = PTR_ALIGN((u8 *)areq_ctx->tail,
			     crypto_ahash_alignmask(auth) + 1);
	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
	unsigned int authsize = crypto_aead_authsize(authenc_esn);
	unsigned int assoclen = req->assoclen;
	unsigned int cryptlen = req->cryptlen;
	struct scatterlist *dst = req->dst;
	u32 tmp[2];

	if (!authsize)
		return 0;

	/* Move high-order bits of sequence number to the end. */
	scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
	scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);

	sg_init_table(areq_ctx->dst, 2);
	dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);

	ahash_request_set_tfm(ahreq, auth);
	ahash_request_set_crypt(ahreq, dst, hash, assoclen + cryptlen);
	ahash_request_set_callback(ahreq, flags,
				   authenc_esn_geniv_ahash_done, req);

	return crypto_ahash_digest(ahreq) ?:
	       crypto_authenc_esn_genicv_tail(req, aead_request_flags(req));
}


static void crypto_authenc_esn_encrypt_done(struct crypto_async_request *req,
					    int err)
{
	struct aead_request *areq = req->data;

	if (!err)
		err = crypto_authenc_esn_genicv(areq, 0);

	authenc_esn_request_complete(areq, err);
}

static int crypto_authenc_esn_copy(struct aead_request *req, unsigned int len)
{
	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);

	skcipher_request_set_sync_tfm(skreq, ctx->null);
	skcipher_request_set_callback(skreq, aead_request_flags(req),
				      NULL, NULL);
	skcipher_request_set_crypt(skreq, req->src, req->dst, len, NULL);

	return crypto_skcipher_encrypt(skreq);
}

static int crypto_authenc_esn_encrypt(struct aead_request *req)
{
	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
	struct skcipher_request *skreq = (void *)(areq_ctx->tail +
						  ctx->reqoff);
	struct crypto_skcipher *enc = ctx->enc;
	unsigned int assoclen = req->assoclen;
	unsigned int cryptlen = req->cryptlen;
	struct scatterlist *src, *dst;
	int err;

	sg_init_table(areq_ctx->src, 2);
	src = scatterwalk_ffwd(areq_ctx->src, req->src, assoclen);
	dst = src;

	if (req->src != req->dst) {
		err = crypto_authenc_esn_copy(req, assoclen);
		if (err)
			return err;

		sg_init_table(areq_ctx->dst, 2);
		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, assoclen);
	}

	skcipher_request_set_tfm(skreq, enc);
	skcipher_request_set_callback(skreq, aead_request_flags(req),
				      crypto_authenc_esn_encrypt_done, req);
	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);

	err = crypto_skcipher_encrypt(skreq);
	if (err)
		return err;

	return crypto_authenc_esn_genicv(req, aead_request_flags(req));
}

static int crypto_authenc_esn_decrypt_tail(struct aead_request *req,
					   unsigned int flags)
{
	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	unsigned int authsize = crypto_aead_authsize(authenc_esn);
	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
	struct skcipher_request *skreq = (void *)(areq_ctx->tail +
						  ctx->reqoff);
	struct crypto_ahash *auth = ctx->auth;
	u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail,
			      crypto_ahash_alignmask(auth) + 1);
	unsigned int cryptlen = req->cryptlen - authsize;
	unsigned int assoclen = req->assoclen;
	struct scatterlist *dst = req->dst;
	u8 *ihash = ohash + crypto_ahash_digestsize(auth);
	u32 tmp[2];

	if (!authsize)
		goto decrypt;

	/* Move high-order bits of sequence number back. */
	scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
	scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);

	if (crypto_memneq(ihash, ohash, authsize))
		return -EBADMSG;

decrypt:

	sg_init_table(areq_ctx->dst, 2);
	dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen);

	skcipher_request_set_tfm(skreq, ctx->enc);
	skcipher_request_set_callback(skreq, flags,
				      req->base.complete, req->base.data);
	skcipher_request_set_crypt(skreq, dst, dst, cryptlen, req->iv);

	return crypto_skcipher_decrypt(skreq);
}

static void authenc_esn_verify_ahash_done(struct crypto_async_request *areq,
					  int err)
{
	struct aead_request *req = areq->data;

	err = err ?: crypto_authenc_esn_decrypt_tail(req, 0);
	authenc_esn_request_complete(req, err);
}

static int crypto_authenc_esn_decrypt(struct aead_request *req)
{
	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
	unsigned int authsize = crypto_aead_authsize(authenc_esn);
	struct crypto_ahash *auth = ctx->auth;
	u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail,
			      crypto_ahash_alignmask(auth) + 1);
	unsigned int assoclen = req->assoclen;
	unsigned int cryptlen = req->cryptlen;
	u8 *ihash = ohash + crypto_ahash_digestsize(auth);
	struct scatterlist *dst = req->dst;
	u32 tmp[2];
	int err;

	cryptlen -= authsize;

	if (req->src != dst) {
		err = crypto_authenc_esn_copy(req, assoclen + cryptlen);
		if (err)
			return err;
	}

	scatterwalk_map_and_copy(ihash, req->src, assoclen + cryptlen,
				 authsize, 0);

	if (!authsize)
		goto tail;

	/* Move high-order bits of sequence number to the end. */
	scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
	scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);

	sg_init_table(areq_ctx->dst, 2);
	dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);

	ahash_request_set_tfm(ahreq, auth);
	ahash_request_set_crypt(ahreq, dst, ohash, assoclen + cryptlen);
	ahash_request_set_callback(ahreq, aead_request_flags(req),
				   authenc_esn_verify_ahash_done, req);

	err = crypto_ahash_digest(ahreq);
	if (err)
		return err;

tail:
	return crypto_authenc_esn_decrypt_tail(req, aead_request_flags(req));
}

static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm)
{
	struct aead_instance *inst = aead_alg_instance(tfm);
	struct authenc_esn_instance_ctx *ictx = aead_instance_ctx(inst);
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
	struct crypto_ahash *auth;
	struct crypto_skcipher *enc;
	struct crypto_sync_skcipher *null;
	int err;

	auth = crypto_spawn_ahash(&ictx->auth);
	if (IS_ERR(auth))
		return PTR_ERR(auth);

	enc = crypto_spawn_skcipher(&ictx->enc);
	err = PTR_ERR(enc);
	if (IS_ERR(enc))
		goto err_free_ahash;

	null = crypto_get_default_null_skcipher();
	err = PTR_ERR(null);
	if (IS_ERR(null))
		goto err_free_skcipher;

	ctx->auth = auth;
	ctx->enc = enc;
	ctx->null = null;

	ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth),
			    crypto_ahash_alignmask(auth) + 1);

	crypto_aead_set_reqsize(
		tfm,
		sizeof(struct authenc_esn_request_ctx) +
		ctx->reqoff +
		max_t(unsigned int,
		      crypto_ahash_reqsize(auth) +
		      sizeof(struct ahash_request),
		      sizeof(struct skcipher_request) +
		      crypto_skcipher_reqsize(enc)));

	return 0;

err_free_skcipher:
	crypto_free_skcipher(enc);
err_free_ahash:
	crypto_free_ahash(auth);
	return err;
}

static void crypto_authenc_esn_exit_tfm(struct crypto_aead *tfm)
{
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);

	crypto_free_ahash(ctx->auth);
	crypto_free_skcipher(ctx->enc);
	crypto_put_default_null_skcipher();
}

static void crypto_authenc_esn_free(struct aead_instance *inst)
{
	struct authenc_esn_instance_ctx *ctx = aead_instance_ctx(inst);

	crypto_drop_skcipher(&ctx->enc);
	crypto_drop_ahash(&ctx->auth);
	kfree(inst);
}

static int crypto_authenc_esn_create(struct crypto_template *tmpl,
				     struct rtattr **tb)
{
	struct crypto_attr_type *algt;
	u32 mask;
	struct aead_instance *inst;
	struct hash_alg_common *auth;
	struct crypto_alg *auth_base;
	struct skcipher_alg *enc;
	struct authenc_esn_instance_ctx *ctx;
	const char *enc_name;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
		return -EINVAL;

	mask = crypto_requires_sync(algt->type, algt->mask);

	auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
			      CRYPTO_ALG_TYPE_AHASH_MASK | mask);
	if (IS_ERR(auth))
		return PTR_ERR(auth);

	auth_base = &auth->base;

	enc_name = crypto_attr_alg_name(tb[2]);
	err = PTR_ERR(enc_name);
	if (IS_ERR(enc_name))
		goto out_put_auth;

	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
	err = -ENOMEM;
	if (!inst)
		goto out_put_auth;

	ctx = aead_instance_ctx(inst);

	err = crypto_init_ahash_spawn(&ctx->auth, auth,
				      aead_crypto_instance(inst));
	if (err)
		goto err_free_inst;

	err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),
				   enc_name, 0, mask);
	if (err)
		goto err_drop_auth;

	enc = crypto_spawn_skcipher_alg(&ctx->enc);

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
		     "authencesn(%s,%s)", auth_base->cra_name,
		     enc->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
		goto err_drop_enc;

	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "authencesn(%s,%s)", auth_base->cra_driver_name,
		     enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
		goto err_drop_enc;

	inst->alg.base.cra_flags = (auth_base->cra_flags |
				    enc->base.cra_flags) & CRYPTO_ALG_ASYNC;
	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
				      auth_base->cra_priority;
	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
	inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
				       enc->base.cra_alignmask;
	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_esn_ctx);

	inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
	inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
	inst->alg.maxauthsize = auth->digestsize;

	inst->alg.init = crypto_authenc_esn_init_tfm;
	inst->alg.exit = crypto_authenc_esn_exit_tfm;

	inst->alg.setkey = crypto_authenc_esn_setkey;
	inst->alg.setauthsize = crypto_authenc_esn_setauthsize;
	inst->alg.encrypt = crypto_authenc_esn_encrypt;
	inst->alg.decrypt = crypto_authenc_esn_decrypt;

	inst->free = crypto_authenc_esn_free,

	err = aead_register_instance(tmpl, inst);
	if (err)
		goto err_drop_enc;

out:
	crypto_mod_put(auth_base);
	return err;

err_drop_enc:
	crypto_drop_skcipher(&ctx->enc);
err_drop_auth:
	crypto_drop_ahash(&ctx->auth);
err_free_inst:
	kfree(inst);
out_put_auth:
	goto out;
}

static struct crypto_template crypto_authenc_esn_tmpl = {
	.name = "authencesn",
	.create = crypto_authenc_esn_create,
	.module = THIS_MODULE,
};

static int __init crypto_authenc_esn_module_init(void)
{
	return crypto_register_template(&crypto_authenc_esn_tmpl);
}

static void __exit crypto_authenc_esn_module_exit(void)
{
	crypto_unregister_template(&crypto_authenc_esn_tmpl);
}

subsys_initcall(crypto_authenc_esn_module_init);
module_exit(crypto_authenc_esn_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steffen Klassert <[email protected]>");
MODULE_DESCRIPTION("AEAD wrapper for IPsec with extended sequence numbers");
MODULE_ALIAS_CRYPTO("authencesn");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
a5079d08 SK	2	/*
	3	* authencesn.c - AEAD wrapper for IPsec with extended sequence numbers,
	4	* derived from authenc.c
	5	*
	6	* Copyright (C) 2010 secunet Security Networks AG
	7	* Copyright (C) 2010 Steffen Klassert <[email protected]>
104880a6	8	* Copyright (c) 2015 Herbert Xu <[email protected]>
a5079d08 SK	9	*/
a5079d08 SK	10
7fb2a4bd	11	#include <crypto/internal/aead.h>
a5079d08 SK	12	#include <crypto/internal/hash.h>
	13	#include <crypto/internal/skcipher.h>
	14	#include <crypto/authenc.h>
104880a6	15	#include <crypto/null.h>
a5079d08 SK	16	#include <crypto/scatterwalk.h>
	17	#include <linux/err.h>
	18	#include <linux/init.h>
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
	21	#include <linux/rtnetlink.h>
	22	#include <linux/slab.h>
	23	#include <linux/spinlock.h>
	24
	25	struct authenc_esn_instance_ctx {
	26	struct crypto_ahash_spawn auth;
	27	struct crypto_skcipher_spawn enc;
	28	};
	29
	30	struct crypto_authenc_esn_ctx {
	31	unsigned int reqoff;
	32	struct crypto_ahash *auth;
e75445a8	33	struct crypto_skcipher *enc;
8d605398	34	struct crypto_sync_skcipher *null;
a5079d08 SK	35	};
	36
	37	struct authenc_esn_request_ctx {
104880a6 HX	38	struct scatterlist src[2];
104880a6 HX	39	struct scatterlist dst[2];
a5079d08 SK	40	char tail[];
	41	};
	42
	43	static void authenc_esn_request_complete(struct aead_request *req, int err)
	44	{
	45	if (err != -EINPROGRESS)
	46	aead_request_complete(req, err);
	47	}
	48
104880a6 HX	49	static int crypto_authenc_esn_setauthsize(struct crypto_aead *authenc_esn,
	50	unsigned int authsize)
	51	{
	52	if (authsize > 0 && authsize < 4)
	53	return -EINVAL;
	54
	55	return 0;
	56	}
	57
a5079d08 SK	58	static int crypto_authenc_esn_setkey(struct crypto_aead authenc_esn, const u8 key,
	59	unsigned int keylen)
	60	{
a5079d08 SK	61	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
a5079d08 SK	62	struct crypto_ahash *auth = ctx->auth;
e75445a8	63	struct crypto_skcipher *enc = ctx->enc;
fddc2c43	64	struct crypto_authenc_keys keys;
a5079d08 SK	65	int err = -EINVAL;
a5079d08 SK	66
fddc2c43	67	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
674f368a	68	goto out;
a5079d08 SK	69
	70	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
	71	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc_esn) &
	72	CRYPTO_TFM_REQ_MASK);
fddc2c43	73	err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
a5079d08 SK	74	if (err)
	75	goto out;
	76
e75445a8 HX	77	crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
e75445a8 HX	78	crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc_esn) &
a5079d08	79	CRYPTO_TFM_REQ_MASK);
e75445a8	80	err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
a5079d08	81	out:
31545df3	82	memzero_explicit(&keys, sizeof(keys));
a5079d08	83	return err;
a5079d08 SK	84	}
a5079d08 SK	85
104880a6 HX	86	static int crypto_authenc_esn_genicv_tail(struct aead_request *req,
104880a6 HX	87	unsigned int flags)
a5079d08	88	{
a5079d08 SK	89	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	90	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
	91	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
104880a6 HX	92	struct crypto_ahash *auth = ctx->auth;
	93	u8 hash = PTR_ALIGN((u8 )areq_ctx->tail,
	94	crypto_ahash_alignmask(auth) + 1);
	95	unsigned int authsize = crypto_aead_authsize(authenc_esn);
	96	unsigned int assoclen = req->assoclen;
	97	unsigned int cryptlen = req->cryptlen;
	98	struct scatterlist *dst = req->dst;
	99	u32 tmp[2];
a5079d08	100
104880a6 HX	101	/* Move high-order bits of sequence number back. */
	102	scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
	103	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
	104	scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);
a5079d08	105
104880a6 HX	106	scatterwalk_map_and_copy(hash, dst, assoclen + cryptlen, authsize, 1);
104880a6 HX	107	return 0;
a5079d08 SK	108	}
a5079d08 SK	109
a5079d08 SK	110	static void authenc_esn_geniv_ahash_done(struct crypto_async_request *areq,
	111	int err)
	112	{
	113	struct aead_request *req = areq->data;
a5079d08	114
104880a6	115	err = err ?: crypto_authenc_esn_genicv_tail(req, 0);
a5079d08 SK	116	aead_request_complete(req, err);
	117	}
	118
104880a6 HX	119	static int crypto_authenc_esn_genicv(struct aead_request *req,
104880a6 HX	120	unsigned int flags)
a5079d08	121	{
a5079d08	122	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
a5079d08	123	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
a5079d08	124	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
104880a6 HX	125	struct crypto_ahash *auth = ctx->auth;
	126	u8 hash = PTR_ALIGN((u8 )areq_ctx->tail,
	127	crypto_ahash_alignmask(auth) + 1);
a5079d08	128	struct ahash_request ahreq = (void )(areq_ctx->tail + ctx->reqoff);
104880a6 HX	129	unsigned int authsize = crypto_aead_authsize(authenc_esn);
104880a6 HX	130	unsigned int assoclen = req->assoclen;
a5079d08	131	unsigned int cryptlen = req->cryptlen;
104880a6 HX	132	struct scatterlist *dst = req->dst;
104880a6 HX	133	u32 tmp[2];
a5079d08	134
104880a6 HX	135	if (!authsize)
104880a6 HX	136	return 0;
a5079d08	137
104880a6 HX	138	/* Move high-order bits of sequence number to the end. */
	139	scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
	140	scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
	141	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);
a5079d08	142
104880a6 HX	143	sg_init_table(areq_ctx->dst, 2);
104880a6 HX	144	dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
a5079d08	145
104880a6 HX	146	ahash_request_set_tfm(ahreq, auth);
	147	ahash_request_set_crypt(ahreq, dst, hash, assoclen + cryptlen);
	148	ahash_request_set_callback(ahreq, flags,
	149	authenc_esn_geniv_ahash_done, req);
a5079d08	150
104880a6 HX	151	return crypto_ahash_digest(ahreq) ?:
104880a6 HX	152	crypto_authenc_esn_genicv_tail(req, aead_request_flags(req));
a5079d08 SK	153	}
	154
	155
104880a6 HX	156	static void crypto_authenc_esn_encrypt_done(struct crypto_async_request *req,
104880a6 HX	157	int err)
a5079d08	158	{
104880a6	159	struct aead_request *areq = req->data;
a5079d08	160
104880a6 HX	161	if (!err)
104880a6 HX	162	err = crypto_authenc_esn_genicv(areq, 0);
a5079d08	163
104880a6	164	authenc_esn_request_complete(areq, err);
a5079d08 SK	165	}
a5079d08 SK	166
104880a6	167	static int crypto_authenc_esn_copy(struct aead_request *req, unsigned int len)
a5079d08 SK	168	{
	169	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	170	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
8d605398	171	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
a5079d08	172
8d605398	173	skcipher_request_set_sync_tfm(skreq, ctx->null);
e75445a8 HX	174	skcipher_request_set_callback(skreq, aead_request_flags(req),
	175	NULL, NULL);
	176	skcipher_request_set_crypt(skreq, req->src, req->dst, len, NULL);
	177
	178	return crypto_skcipher_encrypt(skreq);
a5079d08 SK	179	}
a5079d08 SK	180
104880a6	181	static int crypto_authenc_esn_encrypt(struct aead_request *req)
a5079d08 SK	182	{
	183	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	184	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
104880a6	185	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
e75445a8 HX	186	struct skcipher_request skreq = (void )(areq_ctx->tail +
	187	ctx->reqoff);
	188	struct crypto_skcipher *enc = ctx->enc;
104880a6	189	unsigned int assoclen = req->assoclen;
a5079d08	190	unsigned int cryptlen = req->cryptlen;
104880a6 HX	191	struct scatterlist src, dst;
104880a6 HX	192	int err;
a5079d08	193
104880a6 HX	194	sg_init_table(areq_ctx->src, 2);
	195	src = scatterwalk_ffwd(areq_ctx->src, req->src, assoclen);
	196	dst = src;
a5079d08	197
104880a6 HX	198	if (req->src != req->dst) {
	199	err = crypto_authenc_esn_copy(req, assoclen);
	200	if (err)
	201	return err;
a5079d08	202
104880a6 HX	203	sg_init_table(areq_ctx->dst, 2);
104880a6 HX	204	dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, assoclen);
a5079d08 SK	205	}
a5079d08 SK	206
e75445a8 HX	207	skcipher_request_set_tfm(skreq, enc);
	208	skcipher_request_set_callback(skreq, aead_request_flags(req),
	209	crypto_authenc_esn_encrypt_done, req);
	210	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
a5079d08	211
e75445a8	212	err = crypto_skcipher_encrypt(skreq);
a5079d08 SK	213	if (err)
	214	return err;
	215
104880a6	216	return crypto_authenc_esn_genicv(req, aead_request_flags(req));
a5079d08 SK	217	}
a5079d08 SK	218
104880a6 HX	219	static int crypto_authenc_esn_decrypt_tail(struct aead_request *req,
104880a6 HX	220	unsigned int flags)
a5079d08	221	{
104880a6 HX	222	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	223	unsigned int authsize = crypto_aead_authsize(authenc_esn);
	224	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
	225	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
e75445a8 HX	226	struct skcipher_request skreq = (void )(areq_ctx->tail +
e75445a8 HX	227	ctx->reqoff);
104880a6 HX	228	struct crypto_ahash *auth = ctx->auth;
	229	u8 ohash = PTR_ALIGN((u8 )areq_ctx->tail,
	230	crypto_ahash_alignmask(auth) + 1);
	231	unsigned int cryptlen = req->cryptlen - authsize;
	232	unsigned int assoclen = req->assoclen;
	233	struct scatterlist *dst = req->dst;
	234	u8 *ihash = ohash + crypto_ahash_digestsize(auth);
	235	u32 tmp[2];
a5079d08	236
41cdf7a4 HX	237	if (!authsize)
	238	goto decrypt;
	239
104880a6 HX	240	/* Move high-order bits of sequence number back. */
	241	scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
	242	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
	243	scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);
a5079d08	244
104880a6 HX	245	if (crypto_memneq(ihash, ohash, authsize))
104880a6 HX	246	return -EBADMSG;
a5079d08	247
41cdf7a4 HX	248	decrypt:
41cdf7a4 HX	249
104880a6 HX	250	sg_init_table(areq_ctx->dst, 2);
104880a6 HX	251	dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen);
a5079d08	252
e75445a8 HX	253	skcipher_request_set_tfm(skreq, ctx->enc);
	254	skcipher_request_set_callback(skreq, flags,
	255	req->base.complete, req->base.data);
	256	skcipher_request_set_crypt(skreq, dst, dst, cryptlen, req->iv);
a5079d08	257
e75445a8	258	return crypto_skcipher_decrypt(skreq);
a5079d08 SK	259	}
a5079d08 SK	260
104880a6 HX	261	static void authenc_esn_verify_ahash_done(struct crypto_async_request *areq,
104880a6 HX	262	int err)
a5079d08	263	{
104880a6	264	struct aead_request *req = areq->data;
a5079d08	265
104880a6	266	err = err ?: crypto_authenc_esn_decrypt_tail(req, 0);
a7773363	267	authenc_esn_request_complete(req, err);
a5079d08 SK	268	}
a5079d08 SK	269
104880a6	270	static int crypto_authenc_esn_decrypt(struct aead_request *req)
a5079d08 SK	271	{
	272	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
	273	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
104880a6 HX	274	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
	275	struct ahash_request ahreq = (void )(areq_ctx->tail + ctx->reqoff);
	276	unsigned int authsize = crypto_aead_authsize(authenc_esn);
	277	struct crypto_ahash *auth = ctx->auth;
	278	u8 ohash = PTR_ALIGN((u8 )areq_ctx->tail,
	279	crypto_ahash_alignmask(auth) + 1);
	280	unsigned int assoclen = req->assoclen;
	281	unsigned int cryptlen = req->cryptlen;
	282	u8 *ihash = ohash + crypto_ahash_digestsize(auth);
	283	struct scatterlist *dst = req->dst;
	284	u32 tmp[2];
	285	int err;
a5079d08	286
104880a6	287	cryptlen -= authsize;
a5079d08	288
104880a6 HX	289	if (req->src != dst) {
	290	err = crypto_authenc_esn_copy(req, assoclen + cryptlen);
	291	if (err)
	292	return err;
	293	}
a5079d08	294
104880a6 HX	295	scatterwalk_map_and_copy(ihash, req->src, assoclen + cryptlen,
104880a6 HX	296	authsize, 0);
a5079d08	297
104880a6 HX	298	if (!authsize)
104880a6 HX	299	goto tail;
a5079d08	300
104880a6 HX	301	/* Move high-order bits of sequence number to the end. */
	302	scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
	303	scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
	304	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);
a5079d08	305
104880a6 HX	306	sg_init_table(areq_ctx->dst, 2);
104880a6 HX	307	dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
a5079d08	308
104880a6 HX	309	ahash_request_set_tfm(ahreq, auth);
	310	ahash_request_set_crypt(ahreq, dst, ohash, assoclen + cryptlen);
	311	ahash_request_set_callback(ahreq, aead_request_flags(req),
	312	authenc_esn_verify_ahash_done, req);
a5079d08	313
104880a6	314	err = crypto_ahash_digest(ahreq);
a5079d08 SK	315	if (err)
	316	return err;
	317
104880a6 HX	318	tail:
104880a6 HX	319	return crypto_authenc_esn_decrypt_tail(req, aead_request_flags(req));
a5079d08 SK	320	}
a5079d08 SK	321
104880a6	322	static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm)
a5079d08	323	{
104880a6 HX	324	struct aead_instance *inst = aead_alg_instance(tfm);
	325	struct authenc_esn_instance_ctx *ictx = aead_instance_ctx(inst);
	326	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
a5079d08	327	struct crypto_ahash *auth;
e75445a8	328	struct crypto_skcipher *enc;
8d605398	329	struct crypto_sync_skcipher *null;
a5079d08 SK	330	int err;
	331
	332	auth = crypto_spawn_ahash(&ictx->auth);
	333	if (IS_ERR(auth))
	334	return PTR_ERR(auth);
	335
60425a8b	336	enc = crypto_spawn_skcipher(&ictx->enc);
a5079d08 SK	337	err = PTR_ERR(enc);
	338	if (IS_ERR(enc))
	339	goto err_free_ahash;
	340
3a2d4fb5	341	null = crypto_get_default_null_skcipher();
104880a6 HX	342	err = PTR_ERR(null);
	343	if (IS_ERR(null))
	344	goto err_free_skcipher;
	345
a5079d08 SK	346	ctx->auth = auth;
a5079d08 SK	347	ctx->enc = enc;
104880a6	348	ctx->null = null;
a5079d08	349
104880a6 HX	350	ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth),
104880a6 HX	351	crypto_ahash_alignmask(auth) + 1);
a5079d08	352
104880a6 HX	353	crypto_aead_set_reqsize(
104880a6 HX	354	tfm,
6650d09b HX	355	sizeof(struct authenc_esn_request_ctx) +
	356	ctx->reqoff +
	357	max_t(unsigned int,
e75445a8 HX	358	crypto_ahash_reqsize(auth) +
	359	sizeof(struct ahash_request),
	360	sizeof(struct skcipher_request) +
	361	crypto_skcipher_reqsize(enc)));
a5079d08 SK	362
	363	return 0;
	364
104880a6	365	err_free_skcipher:
e75445a8	366	crypto_free_skcipher(enc);
a5079d08 SK	367	err_free_ahash:
	368	crypto_free_ahash(auth);
	369	return err;
	370	}
	371
104880a6	372	static void crypto_authenc_esn_exit_tfm(struct crypto_aead *tfm)
a5079d08	373	{
104880a6	374	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
a5079d08 SK	375
a5079d08 SK	376	crypto_free_ahash(ctx->auth);
e75445a8	377	crypto_free_skcipher(ctx->enc);
3a2d4fb5	378	crypto_put_default_null_skcipher();
104880a6 HX	379	}
	380
	381	static void crypto_authenc_esn_free(struct aead_instance *inst)
	382	{
	383	struct authenc_esn_instance_ctx *ctx = aead_instance_ctx(inst);
	384
	385	crypto_drop_skcipher(&ctx->enc);
	386	crypto_drop_ahash(&ctx->auth);
	387	kfree(inst);
a5079d08 SK	388	}
a5079d08 SK	389
104880a6 HX	390	static int crypto_authenc_esn_create(struct crypto_template *tmpl,
104880a6 HX	391	struct rtattr **tb)
a5079d08 SK	392	{
a5079d08 SK	393	struct crypto_attr_type *algt;
b9f76ddd	394	u32 mask;
104880a6	395	struct aead_instance *inst;
a5079d08 SK	396	struct hash_alg_common *auth;
a5079d08 SK	397	struct crypto_alg *auth_base;
e75445a8	398	struct skcipher_alg *enc;
a5079d08 SK	399	struct authenc_esn_instance_ctx *ctx;
	400	const char *enc_name;
	401	int err;
	402
	403	algt = crypto_get_attr_type(tb);
a5079d08	404	if (IS_ERR(algt))
104880a6	405	return PTR_ERR(algt);
a5079d08	406
5e4b8c1f	407	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
104880a6	408	return -EINVAL;
a5079d08	409
b9f76ddd EB	410	mask = crypto_requires_sync(algt->type, algt->mask);
b9f76ddd EB	411
a5079d08	412	auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
b9f76ddd	413	CRYPTO_ALG_TYPE_AHASH_MASK \| mask);
a5079d08	414	if (IS_ERR(auth))
104880a6	415	return PTR_ERR(auth);
a5079d08 SK	416
	417	auth_base = &auth->base;
	418
	419	enc_name = crypto_attr_alg_name(tb[2]);
	420	err = PTR_ERR(enc_name);
	421	if (IS_ERR(enc_name))
	422	goto out_put_auth;
	423
	424	inst = kzalloc(sizeof(inst) + sizeof(ctx), GFP_KERNEL);
	425	err = -ENOMEM;
	426	if (!inst)
	427	goto out_put_auth;
	428
104880a6	429	ctx = aead_instance_ctx(inst);
a5079d08	430
104880a6 HX	431	err = crypto_init_ahash_spawn(&ctx->auth, auth,
104880a6 HX	432	aead_crypto_instance(inst));
a5079d08 SK	433	if (err)
	434	goto err_free_inst;
	435
b9f76ddd EB	436	err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),
b9f76ddd EB	437	enc_name, 0, mask);
a5079d08 SK	438	if (err)
	439	goto err_drop_auth;
	440
e75445a8	441	enc = crypto_spawn_skcipher_alg(&ctx->enc);
a5079d08 SK	442
a5079d08 SK	443	err = -ENAMETOOLONG;
104880a6 HX	444	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
104880a6 HX	445	"authencesn(%s,%s)", auth_base->cra_name,
e75445a8	446	enc->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
a5079d08 SK	447	goto err_drop_enc;
a5079d08 SK	448
104880a6	449	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
a5079d08	450	"authencesn(%s,%s)", auth_base->cra_driver_name,
e75445a8	451	enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
a5079d08 SK	452	goto err_drop_enc;
a5079d08 SK	453
e75445a8 HX	454	inst->alg.base.cra_flags = (auth_base->cra_flags \|
	455	enc->base.cra_flags) & CRYPTO_ALG_ASYNC;
	456	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
104880a6	457	auth_base->cra_priority;
e75445a8	458	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
104880a6	459	inst->alg.base.cra_alignmask = auth_base->cra_alignmask \|
e75445a8	460	enc->base.cra_alignmask;
104880a6 HX	461	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_esn_ctx);
104880a6 HX	462
e75445a8 HX	463	inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
e75445a8 HX	464	inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
104880a6	465	inst->alg.maxauthsize = auth->digestsize;
a5079d08	466
104880a6 HX	467	inst->alg.init = crypto_authenc_esn_init_tfm;
104880a6 HX	468	inst->alg.exit = crypto_authenc_esn_exit_tfm;
a5079d08	469
104880a6 HX	470	inst->alg.setkey = crypto_authenc_esn_setkey;
	471	inst->alg.setauthsize = crypto_authenc_esn_setauthsize;
	472	inst->alg.encrypt = crypto_authenc_esn_encrypt;
	473	inst->alg.decrypt = crypto_authenc_esn_decrypt;
a5079d08	474
104880a6	475	inst->free = crypto_authenc_esn_free,
a5079d08	476
104880a6 HX	477	err = aead_register_instance(tmpl, inst);
	478	if (err)
	479	goto err_drop_enc;
a5079d08 SK	480
	481	out:
	482	crypto_mod_put(auth_base);
104880a6	483	return err;
a5079d08 SK	484
	485	err_drop_enc:
	486	crypto_drop_skcipher(&ctx->enc);
	487	err_drop_auth:
	488	crypto_drop_ahash(&ctx->auth);
	489	err_free_inst:
	490	kfree(inst);
	491	out_put_auth:
a5079d08 SK	492	goto out;
	493	}
	494
a5079d08 SK	495	static struct crypto_template crypto_authenc_esn_tmpl = {
a5079d08 SK	496	.name = "authencesn",
104880a6	497	.create = crypto_authenc_esn_create,
a5079d08 SK	498	.module = THIS_MODULE,
	499	};
	500
	501	static int __init crypto_authenc_esn_module_init(void)
	502	{
	503	return crypto_register_template(&crypto_authenc_esn_tmpl);
	504	}
	505
	506	static void __exit crypto_authenc_esn_module_exit(void)
	507	{
	508	crypto_unregister_template(&crypto_authenc_esn_tmpl);
	509	}
	510
c4741b23	511	subsys_initcall(crypto_authenc_esn_module_init);
a5079d08 SK	512	module_exit(crypto_authenc_esn_module_exit);
	513
	514	MODULE_LICENSE("GPL");
	515	MODULE_AUTHOR("Steffen Klassert <[email protected]>");
	516	MODULE_DESCRIPTION("AEAD wrapper for IPsec with extended sequence numbers");
4943ba16	517	MODULE_ALIAS_CRYPTO("authencesn");