// 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 <steffen.klassert@secunet.com> * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> */ #include <crypto/internal/aead.h>#include <crypto/internal/hash.h>#include <crypto/internal/skcipher.h>#include <crypto/authenc.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 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 authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);	u8 *hash = areq_ctx->tail;	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. */	memcpy_from_sglist(tmp, dst, 4, 4);	memcpy_from_sglist(tmp + 1, dst, assoclen + cryptlen, 4);	memcpy_to_sglist(dst, 0, tmp, 8); 	memcpy_to_sglist(dst, assoclen + cryptlen, hash, authsize);	return 0;} static void authenc_esn_geniv_ahash_done(void *data, int err){	struct aead_request *req = 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 = areq_ctx->tail;	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. */	memcpy_from_sglist(tmp, dst, 0, 8);	memcpy_to_sglist(dst, 4, tmp, 4);	memcpy_to_sglist(dst, assoclen + cryptlen, tmp + 1, 4); 	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(void *data, int err){	struct aead_request *areq = data; 	if (!err)		err = crypto_authenc_esn_genicv(areq, 0); 	authenc_esn_request_complete(areq, err);} 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; 	if (assoclen < 8)		return -EINVAL; 	sg_init_table(areq_ctx->src, 2);	src = scatterwalk_ffwd(areq_ctx->src, req->src, assoclen);	dst = src; 	if (req->src != req->dst) {		memcpy_sglist(req->dst, req->src, assoclen);		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 = areq_ctx->tail;	unsigned int cryptlen = req->cryptlen - authsize;	unsigned int assoclen = req->assoclen;	struct scatterlist *src = req->src;	struct scatterlist *dst = req->dst;	u8 *ihash = ohash + crypto_ahash_digestsize(auth);	u32 tmp[2]; 	if (!authsize)		goto decrypt; 	if (src == dst) {		/* Move high-order bits of sequence number back. */		memcpy_from_sglist(tmp, dst, 4, 4);		memcpy_from_sglist(tmp + 1, dst, assoclen + cryptlen, 4);		memcpy_to_sglist(dst, 0, tmp, 8);	} else		memcpy_sglist(dst, src, assoclen); 	if (crypto_memneq(ihash, ohash, authsize))		return -EBADMSG; decrypt: 	dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen);	if (req->src == req->dst)		src = dst;	else		src = scatterwalk_ffwd(areq_ctx->src, src, 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, src, dst, cryptlen, req->iv); 	return crypto_skcipher_decrypt(skreq);} static void authenc_esn_verify_ahash_done(void *data, int err){	struct aead_request *req = 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 = areq_ctx->tail;	unsigned int assoclen = req->assoclen;	unsigned int cryptlen = req->cryptlen;	u8 *ihash = ohash + crypto_ahash_digestsize(auth);	struct scatterlist *src = req->src;	struct scatterlist *dst = req->dst;	u32 tmp[2];	int err; 	if (assoclen < 8)		return -EINVAL; 	if (!authsize)		goto tail; 	cryptlen -= authsize;	memcpy_from_sglist(ihash, req->src, assoclen + cryptlen, authsize); 	/* Move high-order bits of sequence number to the end. */	memcpy_from_sglist(tmp, src, 0, 8);	if (src == dst) {		memcpy_to_sglist(dst, 4, tmp, 4);		memcpy_to_sglist(dst, assoclen + cryptlen, tmp + 1, 4);		dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);	} else {		memcpy_to_sglist(dst, 0, tmp, 4);		memcpy_to_sglist(dst, assoclen + cryptlen - 4, tmp + 1, 4); 		src = scatterwalk_ffwd(areq_ctx->src, src, 8);		dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);		memcpy_sglist(dst, src, assoclen + cryptlen - 8);		dst = req->dst;	} 	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;	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; 	ctx->auth = auth;	ctx->enc = enc; 	ctx->reqoff = 2 * crypto_ahash_digestsize(auth); 	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_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);} 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){	u32 mask;	struct aead_instance *inst;	struct authenc_esn_instance_ctx *ctx;	struct skcipher_alg_common *enc;	struct hash_alg_common *auth;	struct crypto_alg *auth_base;	int err; 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);	if (err)		return err; 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);	if (!inst)		return -ENOMEM;	ctx = aead_instance_ctx(inst); 	err = crypto_grab_ahash(&ctx->auth, aead_crypto_instance(inst),				crypto_attr_alg_name(tb[1]), 0, mask);	if (err)		goto err_free_inst;	auth = crypto_spawn_ahash_alg(&ctx->auth);	auth_base = &auth->base; 	if (auth->digestsize > 0 && auth->digestsize < 4) {		err = -EINVAL;		goto err_free_inst;	} 	err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),				   crypto_attr_alg_name(tb[2]), 0, mask);	if (err)		goto err_free_inst;	enc = crypto_spawn_skcipher_alg_common(&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_free_inst; 	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_free_inst; 	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 = enc->base.cra_alignmask;	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_esn_ctx); 	inst->alg.ivsize = enc->ivsize;	inst->alg.chunksize = enc->chunksize;	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) {err_free_inst:		crypto_authenc_esn_free(inst);	}	return err;} 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);} module_init(crypto_authenc_esn_module_init);module_exit(crypto_authenc_esn_module_exit); MODULE_LICENSE("GPL");MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");MODULE_DESCRIPTION("AEAD wrapper for IPsec with extended sequence numbers");MODULE_ALIAS_CRYPTO("authencesn");