| /* | 
 |  * Authenc: Simple AEAD wrapper for IPsec | 
 |  * | 
 |  * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> | 
 |  * | 
 |  * This program is free software; you can redistribute it and/or modify it | 
 |  * under the terms of the GNU General Public License as published by the Free | 
 |  * Software Foundation; either version 2 of the License, or (at your option) | 
 |  * any later version. | 
 |  * | 
 |  */ | 
 |  | 
 | #include <crypto/algapi.h> | 
 | #include <linux/err.h> | 
 | #include <linux/init.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/module.h> | 
 | #include <linux/slab.h> | 
 | #include <linux/spinlock.h> | 
 |  | 
 | #include "scatterwalk.h" | 
 |  | 
 | struct authenc_instance_ctx { | 
 | 	struct crypto_spawn auth; | 
 | 	struct crypto_spawn enc; | 
 |  | 
 | 	unsigned int authsize; | 
 | 	unsigned int enckeylen; | 
 | }; | 
 |  | 
 | struct crypto_authenc_ctx { | 
 | 	spinlock_t auth_lock; | 
 | 	struct crypto_hash *auth; | 
 | 	struct crypto_ablkcipher *enc; | 
 | }; | 
 |  | 
 | static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key, | 
 | 				 unsigned int keylen) | 
 | { | 
 | 	struct authenc_instance_ctx *ictx = | 
 | 		crypto_instance_ctx(crypto_aead_alg_instance(authenc)); | 
 | 	unsigned int enckeylen = ictx->enckeylen; | 
 | 	unsigned int authkeylen; | 
 | 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); | 
 | 	struct crypto_hash *auth = ctx->auth; | 
 | 	struct crypto_ablkcipher *enc = ctx->enc; | 
 | 	int err = -EINVAL; | 
 |  | 
 | 	if (keylen < enckeylen) { | 
 | 		crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN); | 
 | 		goto out; | 
 | 	} | 
 | 	authkeylen = keylen - enckeylen; | 
 |  | 
 | 	crypto_hash_clear_flags(auth, CRYPTO_TFM_REQ_MASK); | 
 | 	crypto_hash_set_flags(auth, crypto_aead_get_flags(authenc) & | 
 | 				    CRYPTO_TFM_REQ_MASK); | 
 | 	err = crypto_hash_setkey(auth, key, authkeylen); | 
 | 	crypto_aead_set_flags(authenc, crypto_hash_get_flags(auth) & | 
 | 				       CRYPTO_TFM_RES_MASK); | 
 |  | 
 | 	if (err) | 
 | 		goto out; | 
 |  | 
 | 	crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK); | 
 | 	crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) & | 
 | 					 CRYPTO_TFM_REQ_MASK); | 
 | 	err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen); | 
 | 	crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) & | 
 | 				       CRYPTO_TFM_RES_MASK); | 
 |  | 
 | out: | 
 | 	return err; | 
 | } | 
 |  | 
 | static int crypto_authenc_hash(struct aead_request *req) | 
 | { | 
 | 	struct crypto_aead *authenc = crypto_aead_reqtfm(req); | 
 | 	struct authenc_instance_ctx *ictx = | 
 | 		crypto_instance_ctx(crypto_aead_alg_instance(authenc)); | 
 | 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); | 
 | 	struct crypto_hash *auth = ctx->auth; | 
 | 	struct hash_desc desc = { | 
 | 		.tfm = auth, | 
 | 	}; | 
 | 	u8 *hash = aead_request_ctx(req); | 
 | 	struct scatterlist *dst; | 
 | 	unsigned int cryptlen; | 
 | 	int err; | 
 |  | 
 | 	hash = (u8 *)ALIGN((unsigned long)hash + crypto_hash_alignmask(auth),  | 
 | 			   crypto_hash_alignmask(auth) + 1); | 
 |  | 
 | 	spin_lock_bh(&ctx->auth_lock); | 
 | 	err = crypto_hash_init(&desc); | 
 | 	if (err) | 
 | 		goto auth_unlock; | 
 |  | 
 | 	err = crypto_hash_update(&desc, req->assoc, req->assoclen); | 
 | 	if (err) | 
 | 		goto auth_unlock; | 
 |  | 
 | 	cryptlen = req->cryptlen; | 
 | 	dst = req->dst; | 
 | 	err = crypto_hash_update(&desc, dst, cryptlen); | 
 | 	if (err) | 
 | 		goto auth_unlock; | 
 |  | 
 | 	err = crypto_hash_final(&desc, hash); | 
 | auth_unlock: | 
 | 	spin_unlock_bh(&ctx->auth_lock); | 
 |  | 
 | 	if (err) | 
 | 		return err; | 
 |  | 
 | 	scatterwalk_map_and_copy(hash, dst, cryptlen, ictx->authsize, 1); | 
 | 	return 0; | 
 | } | 
 |  | 
 | static void crypto_authenc_encrypt_done(struct crypto_async_request *req, | 
 | 					int err) | 
 | { | 
 | 	if (!err) | 
 | 		err = crypto_authenc_hash(req->data); | 
 |  | 
 | 	aead_request_complete(req->data, err); | 
 | } | 
 |  | 
 | static int crypto_authenc_encrypt(struct aead_request *req) | 
 | { | 
 | 	struct crypto_aead *authenc = crypto_aead_reqtfm(req); | 
 | 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); | 
 | 	struct ablkcipher_request *abreq = aead_request_ctx(req); | 
 | 	int err; | 
 |  | 
 | 	ablkcipher_request_set_tfm(abreq, ctx->enc); | 
 | 	ablkcipher_request_set_callback(abreq, aead_request_flags(req), | 
 | 					crypto_authenc_encrypt_done, req); | 
 | 	ablkcipher_request_set_crypt(abreq, req->src, req->dst, req->cryptlen, | 
 | 				     req->iv); | 
 |  | 
 | 	err = crypto_ablkcipher_encrypt(abreq); | 
 | 	if (err) | 
 | 		return err; | 
 |  | 
 | 	return crypto_authenc_hash(req); | 
 | } | 
 |  | 
 | static int crypto_authenc_verify(struct aead_request *req) | 
 | { | 
 | 	struct crypto_aead *authenc = crypto_aead_reqtfm(req); | 
 | 	struct authenc_instance_ctx *ictx = | 
 | 		crypto_instance_ctx(crypto_aead_alg_instance(authenc)); | 
 | 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); | 
 | 	struct crypto_hash *auth = ctx->auth; | 
 | 	struct hash_desc desc = { | 
 | 		.tfm = auth, | 
 | 		.flags = aead_request_flags(req), | 
 | 	}; | 
 | 	u8 *ohash = aead_request_ctx(req); | 
 | 	u8 *ihash; | 
 | 	struct scatterlist *src; | 
 | 	unsigned int cryptlen; | 
 | 	unsigned int authsize; | 
 | 	int err; | 
 |  | 
 | 	ohash = (u8 *)ALIGN((unsigned long)ohash + crypto_hash_alignmask(auth),  | 
 | 			    crypto_hash_alignmask(auth) + 1); | 
 | 	ihash = ohash + crypto_hash_digestsize(auth); | 
 |  | 
 | 	spin_lock_bh(&ctx->auth_lock); | 
 | 	err = crypto_hash_init(&desc); | 
 | 	if (err) | 
 | 		goto auth_unlock; | 
 |  | 
 | 	err = crypto_hash_update(&desc, req->assoc, req->assoclen); | 
 | 	if (err) | 
 | 		goto auth_unlock; | 
 |  | 
 | 	cryptlen = req->cryptlen; | 
 | 	src = req->src; | 
 | 	err = crypto_hash_update(&desc, src, cryptlen); | 
 | 	if (err) | 
 | 		goto auth_unlock; | 
 |  | 
 | 	err = crypto_hash_final(&desc, ohash); | 
 | auth_unlock: | 
 | 	spin_unlock_bh(&ctx->auth_lock); | 
 |  | 
 | 	if (err) | 
 | 		return err; | 
 |  | 
 | 	authsize = ictx->authsize; | 
 | 	scatterwalk_map_and_copy(ihash, src, cryptlen, authsize, 0); | 
 | 	return memcmp(ihash, ohash, authsize) ? -EINVAL : 0; | 
 | } | 
 |  | 
 | static void crypto_authenc_decrypt_done(struct crypto_async_request *req, | 
 | 					int err) | 
 | { | 
 | 	aead_request_complete(req->data, err); | 
 | } | 
 |  | 
 | static int crypto_authenc_decrypt(struct aead_request *req) | 
 | { | 
 | 	struct crypto_aead *authenc = crypto_aead_reqtfm(req); | 
 | 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); | 
 | 	struct ablkcipher_request *abreq = aead_request_ctx(req); | 
 | 	int err; | 
 |  | 
 | 	err = crypto_authenc_verify(req); | 
 | 	if (err) | 
 | 		return err; | 
 |  | 
 | 	ablkcipher_request_set_tfm(abreq, ctx->enc); | 
 | 	ablkcipher_request_set_callback(abreq, aead_request_flags(req), | 
 | 					crypto_authenc_decrypt_done, req); | 
 | 	ablkcipher_request_set_crypt(abreq, req->src, req->dst, req->cryptlen, | 
 | 				     req->iv); | 
 |  | 
 | 	return crypto_ablkcipher_decrypt(abreq); | 
 | } | 
 |  | 
 | static int crypto_authenc_init_tfm(struct crypto_tfm *tfm) | 
 | { | 
 | 	struct crypto_instance *inst = (void *)tfm->__crt_alg; | 
 | 	struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst); | 
 | 	struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm); | 
 | 	struct crypto_hash *auth; | 
 | 	struct crypto_ablkcipher *enc; | 
 | 	unsigned int digestsize; | 
 | 	int err; | 
 |  | 
 | 	auth = crypto_spawn_hash(&ictx->auth); | 
 | 	if (IS_ERR(auth)) | 
 | 		return PTR_ERR(auth); | 
 |  | 
 | 	err = -EINVAL; | 
 | 	digestsize = crypto_hash_digestsize(auth); | 
 | 	if (ictx->authsize > digestsize) | 
 | 		goto err_free_hash; | 
 |  | 
 | 	enc = crypto_spawn_ablkcipher(&ictx->enc); | 
 | 	err = PTR_ERR(enc); | 
 | 	if (IS_ERR(enc)) | 
 | 		goto err_free_hash; | 
 |  | 
 | 	ctx->auth = auth; | 
 | 	ctx->enc = enc; | 
 | 	tfm->crt_aead.reqsize = max_t(unsigned int, | 
 | 				      (crypto_hash_alignmask(auth) & | 
 | 				       ~(crypto_tfm_ctx_alignment() - 1)) + | 
 | 				      digestsize * 2, | 
 | 				      sizeof(struct ablkcipher_request) + | 
 | 				      crypto_ablkcipher_reqsize(enc)); | 
 |  | 
 | 	spin_lock_init(&ctx->auth_lock); | 
 |  | 
 | 	return 0; | 
 |  | 
 | err_free_hash: | 
 | 	crypto_free_hash(auth); | 
 | 	return err; | 
 | } | 
 |  | 
 | static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm) | 
 | { | 
 | 	struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm); | 
 |  | 
 | 	crypto_free_hash(ctx->auth); | 
 | 	crypto_free_ablkcipher(ctx->enc); | 
 | } | 
 |  | 
 | static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb) | 
 | { | 
 | 	struct crypto_instance *inst; | 
 | 	struct crypto_alg *auth; | 
 | 	struct crypto_alg *enc; | 
 | 	struct authenc_instance_ctx *ctx; | 
 | 	unsigned int authsize; | 
 | 	unsigned int enckeylen; | 
 | 	int err; | 
 |  | 
 | 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD); | 
 | 	if (err) | 
 | 		return ERR_PTR(err); | 
 |  | 
 | 	auth = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH, | 
 | 			       CRYPTO_ALG_TYPE_HASH_MASK); | 
 | 	if (IS_ERR(auth)) | 
 | 		return ERR_PTR(PTR_ERR(auth)); | 
 |  | 
 | 	err = crypto_attr_u32(tb[2], &authsize); | 
 | 	inst = ERR_PTR(err); | 
 | 	if (err) | 
 | 		goto out_put_auth; | 
 |  | 
 | 	enc = crypto_attr_alg(tb[3], CRYPTO_ALG_TYPE_BLKCIPHER, | 
 | 			      CRYPTO_ALG_TYPE_MASK); | 
 | 	inst = ERR_PTR(PTR_ERR(enc)); | 
 | 	if (IS_ERR(enc)) | 
 | 		goto out_put_auth; | 
 |  | 
 | 	err = crypto_attr_u32(tb[4], &enckeylen); | 
 | 	if (err) | 
 | 		goto out_put_enc; | 
 |  | 
 | 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | 
 | 	err = -ENOMEM; | 
 | 	if (!inst) | 
 | 		goto out_put_enc; | 
 |  | 
 | 	err = -ENAMETOOLONG; | 
 | 	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, | 
 | 		     "authenc(%s,%u,%s,%u)", auth->cra_name, authsize, | 
 | 		     enc->cra_name, enckeylen) >= CRYPTO_MAX_ALG_NAME) | 
 | 		goto err_free_inst; | 
 |  | 
 | 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, | 
 | 		     "authenc(%s,%u,%s,%u)", auth->cra_driver_name, | 
 | 		     authsize, enc->cra_driver_name, enckeylen) >= | 
 | 	    CRYPTO_MAX_ALG_NAME) | 
 | 		goto err_free_inst; | 
 |  | 
 | 	ctx = crypto_instance_ctx(inst); | 
 | 	ctx->authsize = authsize; | 
 | 	ctx->enckeylen = enckeylen; | 
 |  | 
 | 	err = crypto_init_spawn(&ctx->auth, auth, inst, CRYPTO_ALG_TYPE_MASK); | 
 | 	if (err) | 
 | 		goto err_free_inst; | 
 |  | 
 | 	err = crypto_init_spawn(&ctx->enc, enc, inst, CRYPTO_ALG_TYPE_MASK); | 
 | 	if (err) | 
 | 		goto err_drop_auth; | 
 |  | 
 | 	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC; | 
 | 	inst->alg.cra_priority = enc->cra_priority * 10 + auth->cra_priority; | 
 | 	inst->alg.cra_blocksize = enc->cra_blocksize; | 
 | 	inst->alg.cra_alignmask = max(auth->cra_alignmask, enc->cra_alignmask); | 
 | 	inst->alg.cra_type = &crypto_aead_type; | 
 |  | 
 | 	inst->alg.cra_aead.ivsize = enc->cra_blkcipher.ivsize; | 
 | 	inst->alg.cra_aead.authsize = authsize; | 
 |  | 
 | 	inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx); | 
 |  | 
 | 	inst->alg.cra_init = crypto_authenc_init_tfm; | 
 | 	inst->alg.cra_exit = crypto_authenc_exit_tfm; | 
 |  | 
 | 	inst->alg.cra_aead.setkey = crypto_authenc_setkey; | 
 | 	inst->alg.cra_aead.encrypt = crypto_authenc_encrypt; | 
 | 	inst->alg.cra_aead.decrypt = crypto_authenc_decrypt; | 
 |  | 
 | out: | 
 | 	crypto_mod_put(enc); | 
 | out_put_auth: | 
 | 	crypto_mod_put(auth); | 
 | 	return inst; | 
 |  | 
 | err_drop_auth: | 
 | 	crypto_drop_spawn(&ctx->auth); | 
 | err_free_inst: | 
 | 	kfree(inst); | 
 | out_put_enc: | 
 | 	inst = ERR_PTR(err); | 
 | 	goto out; | 
 | } | 
 |  | 
 | static void crypto_authenc_free(struct crypto_instance *inst) | 
 | { | 
 | 	struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst); | 
 |  | 
 | 	crypto_drop_spawn(&ctx->enc); | 
 | 	crypto_drop_spawn(&ctx->auth); | 
 | 	kfree(inst); | 
 | } | 
 |  | 
 | static struct crypto_template crypto_authenc_tmpl = { | 
 | 	.name = "authenc", | 
 | 	.alloc = crypto_authenc_alloc, | 
 | 	.free = crypto_authenc_free, | 
 | 	.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"); |