// SPDX-License-Identifier: GPL-2.0-or-later/* * Authenc: Simple AEAD wrapper for IPsec * * Copyright (c) 2007-2015 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_instance_ctx {	struct crypto_ahash_spawn auth;	struct crypto_skcipher_spawn enc;	unsigned int reqoff;}; struct crypto_authenc_ctx {	struct crypto_ahash *auth;	struct crypto_skcipher *enc;}; struct authenc_request_ctx {	struct scatterlist src[2];	struct scatterlist dst[2];	char tail[];}; static void authenc_request_complete(struct aead_request *req, int err){	if (err != -EINPROGRESS && err != -EBUSY)		aead_request_complete(req, err);} int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,			       unsigned int keylen){	struct rtattr *rta = (struct rtattr *)key;	struct crypto_authenc_key_param *param; 	if (!RTA_OK(rta, keylen))		return -EINVAL;	if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)		return -EINVAL; 	/*	 * RTA_OK() didn't align the rtattr's payload when validating that it	 * fits in the buffer.  Yet, the keys should start on the next 4-byte	 * aligned boundary.  To avoid confusion, require that the rtattr	 * payload be exactly the param struct, which has a 4-byte aligned size.	 */	if (RTA_PAYLOAD(rta) != sizeof(*param))		return -EINVAL;	BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO); 	param = RTA_DATA(rta);	keys->enckeylen = be32_to_cpu(param->enckeylen); 	key += rta->rta_len;	keylen -= rta->rta_len; 	if (keylen < keys->enckeylen)		return -EINVAL; 	keys->authkeylen = keylen - keys->enckeylen;	keys->authkey = key;	keys->enckey = key + keys->authkeylen; 	return 0;}EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys); static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,				 unsigned int keylen){	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);	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) &				    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) &				       CRYPTO_TFM_REQ_MASK);	err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);out:	memzero_explicit(&keys, sizeof(keys));	return err;} static void authenc_geniv_ahash_finish(struct aead_request *req){	struct crypto_aead *authenc = crypto_aead_reqtfm(req);	struct aead_instance *inst = aead_alg_instance(authenc);	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff); 	scatterwalk_map_and_copy(ahreq->result, req->dst,				 req->assoclen + req->cryptlen,				 crypto_aead_authsize(authenc), 1);} static void authenc_geniv_ahash_done(void *data, int err){	struct aead_request *req = data; 	if (!err)		authenc_geniv_ahash_finish(req);	aead_request_complete(req, err);} /* * Used when the ahash request was invoked in the async callback context * of the previous skcipher request.  Eat any EINPROGRESS notifications. */static void authenc_geniv_ahash_done2(void *data, int err){	struct aead_request *req = data; 	if (!err)		authenc_geniv_ahash_finish(req);	authenc_request_complete(req, err);} static int crypto_authenc_genicv(struct aead_request *req, unsigned int mask){	struct crypto_aead *authenc = crypto_aead_reqtfm(req);	struct aead_instance *inst = aead_alg_instance(authenc);	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);	struct crypto_ahash *auth = ctx->auth;	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);	unsigned int flags = aead_request_flags(req) & ~mask;	u8 *hash = areq_ctx->tail;	int err; 	ahash_request_set_tfm(ahreq, auth);	ahash_request_set_crypt(ahreq, req->dst, hash,				req->assoclen + req->cryptlen);	ahash_request_set_callback(ahreq, flags,				   mask ? authenc_geniv_ahash_done2 :					  authenc_geniv_ahash_done, req); 	err = crypto_ahash_digest(ahreq);	if (err)		return err; 	scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,				 crypto_aead_authsize(authenc), 1); 	return 0;} static void crypto_authenc_encrypt_done(void *data, int err){	struct aead_request *areq = data; 	if (err) {		aead_request_complete(areq, err);		return;	}	err = crypto_authenc_genicv(areq, CRYPTO_TFM_REQ_MAY_SLEEP);	authenc_request_complete(areq, err);} static int crypto_authenc_encrypt(struct aead_request *req){	struct crypto_aead *authenc = crypto_aead_reqtfm(req);	struct aead_instance *inst = aead_alg_instance(authenc);	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);	struct crypto_skcipher *enc = ctx->enc;	unsigned int cryptlen = req->cryptlen;	struct skcipher_request *skreq = (void *)(areq_ctx->tail +						  ictx->reqoff);	struct scatterlist *src, *dst;	int err; 	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);	dst = src; 	if (req->src != req->dst) {		memcpy_sglist(req->dst, req->src, req->assoclen);		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);	} 	skcipher_request_set_tfm(skreq, enc);	skcipher_request_set_callback(skreq, aead_request_flags(req),				      crypto_authenc_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_genicv(req, 0);} static void authenc_decrypt_tail_done(void *data, int err){	struct aead_request *req = data; 	authenc_request_complete(req, err);} static int crypto_authenc_decrypt_tail(struct aead_request *req,				       unsigned int mask){	struct crypto_aead *authenc = crypto_aead_reqtfm(req);	struct aead_instance *inst = aead_alg_instance(authenc);	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);	struct skcipher_request *skreq = (void *)(areq_ctx->tail +						  ictx->reqoff);	unsigned int authsize = crypto_aead_authsize(authenc);	unsigned int flags = aead_request_flags(req) & ~mask;	u8 *ihash = ahreq->result + authsize;	struct scatterlist *src, *dst; 	scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0); 	if (crypto_memneq(ihash, ahreq->result, authsize))		return -EBADMSG; 	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);	dst = src; 	if (req->src != req->dst)		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen); 	skcipher_request_set_tfm(skreq, ctx->enc);	skcipher_request_set_callback(skreq, flags,				      mask ? authenc_decrypt_tail_done :					     req->base.complete,				      mask ? req : req->base.data);	skcipher_request_set_crypt(skreq, src, dst,				   req->cryptlen - authsize, req->iv); 	return crypto_skcipher_decrypt(skreq);} static void authenc_verify_ahash_done(void *data, int err){	struct aead_request *req = data; 	if (err) {		aead_request_complete(req, err);		return;	}	err = crypto_authenc_decrypt_tail(req, CRYPTO_TFM_REQ_MAY_SLEEP);	authenc_request_complete(req, err);} static int crypto_authenc_decrypt(struct aead_request *req){	struct crypto_aead *authenc = crypto_aead_reqtfm(req);	unsigned int authsize = crypto_aead_authsize(authenc);	struct aead_instance *inst = aead_alg_instance(authenc);	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);	struct crypto_ahash *auth = ctx->auth;	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);	u8 *hash = areq_ctx->tail;	int err; 	ahash_request_set_tfm(ahreq, auth);	ahash_request_set_crypt(ahreq, req->src, hash,				req->assoclen + req->cryptlen - authsize);	ahash_request_set_callback(ahreq, aead_request_flags(req),				   authenc_verify_ahash_done, req); 	err = crypto_ahash_digest(ahreq);	if (err)		return err; 	return crypto_authenc_decrypt_tail(req, 0);} static int crypto_authenc_init_tfm(struct crypto_aead *tfm){	struct aead_instance *inst = aead_alg_instance(tfm);	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);	struct crypto_authenc_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; 	crypto_aead_set_reqsize(		tfm,		sizeof(struct authenc_request_ctx) +		ictx->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_exit_tfm(struct crypto_aead *tfm){	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm); 	crypto_free_ahash(ctx->auth);	crypto_free_skcipher(ctx->enc);} static void crypto_authenc_free(struct aead_instance *inst){	struct authenc_instance_ctx *ctx = aead_instance_ctx(inst); 	crypto_drop_skcipher(&ctx->enc);	crypto_drop_ahash(&ctx->auth);	kfree(inst);} static int crypto_authenc_create(struct crypto_template *tmpl,				 struct rtattr **tb){	u32 mask;	struct aead_instance *inst;	struct authenc_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; 	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); 	ctx->reqoff = 2 * auth->digestsize; 	err = -ENAMETOOLONG;	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,		     "authenc(%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,		     "authenc(%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_ctx); 	inst->alg.ivsize = enc->ivsize;	inst->alg.chunksize = enc->chunksize;	inst->alg.maxauthsize = auth->digestsize; 	inst->alg.init = crypto_authenc_init_tfm;	inst->alg.exit = crypto_authenc_exit_tfm; 	inst->alg.setkey = crypto_authenc_setkey;	inst->alg.encrypt = crypto_authenc_encrypt;	inst->alg.decrypt = crypto_authenc_decrypt; 	inst->free = crypto_authenc_free; 	err = aead_register_instance(tmpl, inst);	if (err) {err_free_inst:		crypto_authenc_free(inst);	}	return err;} static struct crypto_template crypto_authenc_tmpl = {	.name = "authenc",	.create = crypto_authenc_create,	.module = THIS_MODULE,}; static int __init crypto_authenc_module_init(void){	return crypto_register_template(&crypto_authenc_tmpl);} static void __exit crypto_authenc_module_exit(void){	crypto_unregister_template(&crypto_authenc_tmpl);} module_init(crypto_authenc_module_init);module_exit(crypto_authenc_module_exit); MODULE_LICENSE("GPL");MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");MODULE_ALIAS_CRYPTO("authenc");