cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

authenc.c (13385B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Authenc: Simple AEAD wrapper for IPsec
      4 *
      5 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
      6 */
      7
      8#include <crypto/internal/aead.h>
      9#include <crypto/internal/hash.h>
     10#include <crypto/internal/skcipher.h>
     11#include <crypto/authenc.h>
     12#include <crypto/null.h>
     13#include <crypto/scatterwalk.h>
     14#include <linux/err.h>
     15#include <linux/init.h>
     16#include <linux/kernel.h>
     17#include <linux/module.h>
     18#include <linux/rtnetlink.h>
     19#include <linux/slab.h>
     20#include <linux/spinlock.h>
     21
     22struct authenc_instance_ctx {
     23	struct crypto_ahash_spawn auth;
     24	struct crypto_skcipher_spawn enc;
     25	unsigned int reqoff;
     26};
     27
     28struct crypto_authenc_ctx {
     29	struct crypto_ahash *auth;
     30	struct crypto_skcipher *enc;
     31	struct crypto_sync_skcipher *null;
     32};
     33
     34struct authenc_request_ctx {
     35	struct scatterlist src[2];
     36	struct scatterlist dst[2];
     37	char tail[];
     38};
     39
     40static void authenc_request_complete(struct aead_request *req, int err)
     41{
     42	if (err != -EINPROGRESS)
     43		aead_request_complete(req, err);
     44}
     45
     46int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
     47			       unsigned int keylen)
     48{
     49	struct rtattr *rta = (struct rtattr *)key;
     50	struct crypto_authenc_key_param *param;
     51
     52	if (!RTA_OK(rta, keylen))
     53		return -EINVAL;
     54	if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
     55		return -EINVAL;
     56
     57	/*
     58	 * RTA_OK() didn't align the rtattr's payload when validating that it
     59	 * fits in the buffer.  Yet, the keys should start on the next 4-byte
     60	 * aligned boundary.  To avoid confusion, require that the rtattr
     61	 * payload be exactly the param struct, which has a 4-byte aligned size.
     62	 */
     63	if (RTA_PAYLOAD(rta) != sizeof(*param))
     64		return -EINVAL;
     65	BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO);
     66
     67	param = RTA_DATA(rta);
     68	keys->enckeylen = be32_to_cpu(param->enckeylen);
     69
     70	key += rta->rta_len;
     71	keylen -= rta->rta_len;
     72
     73	if (keylen < keys->enckeylen)
     74		return -EINVAL;
     75
     76	keys->authkeylen = keylen - keys->enckeylen;
     77	keys->authkey = key;
     78	keys->enckey = key + keys->authkeylen;
     79
     80	return 0;
     81}
     82EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
     83
     84static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
     85				 unsigned int keylen)
     86{
     87	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
     88	struct crypto_ahash *auth = ctx->auth;
     89	struct crypto_skcipher *enc = ctx->enc;
     90	struct crypto_authenc_keys keys;
     91	int err = -EINVAL;
     92
     93	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
     94		goto out;
     95
     96	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
     97	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
     98				    CRYPTO_TFM_REQ_MASK);
     99	err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
    100	if (err)
    101		goto out;
    102
    103	crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
    104	crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
    105				       CRYPTO_TFM_REQ_MASK);
    106	err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
    107out:
    108	memzero_explicit(&keys, sizeof(keys));
    109	return err;
    110}
    111
    112static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
    113{
    114	struct aead_request *req = areq->data;
    115	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
    116	struct aead_instance *inst = aead_alg_instance(authenc);
    117	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
    118	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
    119	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
    120
    121	if (err)
    122		goto out;
    123
    124	scatterwalk_map_and_copy(ahreq->result, req->dst,
    125				 req->assoclen + req->cryptlen,
    126				 crypto_aead_authsize(authenc), 1);
    127
    128out:
    129	aead_request_complete(req, err);
    130}
    131
    132static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
    133{
    134	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
    135	struct aead_instance *inst = aead_alg_instance(authenc);
    136	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
    137	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
    138	struct crypto_ahash *auth = ctx->auth;
    139	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
    140	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
    141	u8 *hash = areq_ctx->tail;
    142	int err;
    143
    144	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
    145			   crypto_ahash_alignmask(auth) + 1);
    146
    147	ahash_request_set_tfm(ahreq, auth);
    148	ahash_request_set_crypt(ahreq, req->dst, hash,
    149				req->assoclen + req->cryptlen);
    150	ahash_request_set_callback(ahreq, flags,
    151				   authenc_geniv_ahash_done, req);
    152
    153	err = crypto_ahash_digest(ahreq);
    154	if (err)
    155		return err;
    156
    157	scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
    158				 crypto_aead_authsize(authenc), 1);
    159
    160	return 0;
    161}
    162
    163static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
    164					int err)
    165{
    166	struct aead_request *areq = req->data;
    167
    168	if (err)
    169		goto out;
    170
    171	err = crypto_authenc_genicv(areq, 0);
    172
    173out:
    174	authenc_request_complete(areq, err);
    175}
    176
    177static int crypto_authenc_copy_assoc(struct aead_request *req)
    178{
    179	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
    180	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
    181	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
    182
    183	skcipher_request_set_sync_tfm(skreq, ctx->null);
    184	skcipher_request_set_callback(skreq, aead_request_flags(req),
    185				      NULL, NULL);
    186	skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
    187				   NULL);
    188
    189	return crypto_skcipher_encrypt(skreq);
    190}
    191
    192static int crypto_authenc_encrypt(struct aead_request *req)
    193{
    194	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
    195	struct aead_instance *inst = aead_alg_instance(authenc);
    196	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
    197	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
    198	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
    199	struct crypto_skcipher *enc = ctx->enc;
    200	unsigned int cryptlen = req->cryptlen;
    201	struct skcipher_request *skreq = (void *)(areq_ctx->tail +
    202						  ictx->reqoff);
    203	struct scatterlist *src, *dst;
    204	int err;
    205
    206	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
    207	dst = src;
    208
    209	if (req->src != req->dst) {
    210		err = crypto_authenc_copy_assoc(req);
    211		if (err)
    212			return err;
    213
    214		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
    215	}
    216
    217	skcipher_request_set_tfm(skreq, enc);
    218	skcipher_request_set_callback(skreq, aead_request_flags(req),
    219				      crypto_authenc_encrypt_done, req);
    220	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
    221
    222	err = crypto_skcipher_encrypt(skreq);
    223	if (err)
    224		return err;
    225
    226	return crypto_authenc_genicv(req, aead_request_flags(req));
    227}
    228
    229static int crypto_authenc_decrypt_tail(struct aead_request *req,
    230				       unsigned int flags)
    231{
    232	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
    233	struct aead_instance *inst = aead_alg_instance(authenc);
    234	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
    235	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
    236	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
    237	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
    238	struct skcipher_request *skreq = (void *)(areq_ctx->tail +
    239						  ictx->reqoff);
    240	unsigned int authsize = crypto_aead_authsize(authenc);
    241	u8 *ihash = ahreq->result + authsize;
    242	struct scatterlist *src, *dst;
    243
    244	scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);
    245
    246	if (crypto_memneq(ihash, ahreq->result, authsize))
    247		return -EBADMSG;
    248
    249	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
    250	dst = src;
    251
    252	if (req->src != req->dst)
    253		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
    254
    255	skcipher_request_set_tfm(skreq, ctx->enc);
    256	skcipher_request_set_callback(skreq, flags,
    257				      req->base.complete, req->base.data);
    258	skcipher_request_set_crypt(skreq, src, dst,
    259				   req->cryptlen - authsize, req->iv);
    260
    261	return crypto_skcipher_decrypt(skreq);
    262}
    263
    264static void authenc_verify_ahash_done(struct crypto_async_request *areq,
    265				      int err)
    266{
    267	struct aead_request *req = areq->data;
    268
    269	if (err)
    270		goto out;
    271
    272	err = crypto_authenc_decrypt_tail(req, 0);
    273
    274out:
    275	authenc_request_complete(req, err);
    276}
    277
    278static int crypto_authenc_decrypt(struct aead_request *req)
    279{
    280	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
    281	unsigned int authsize = crypto_aead_authsize(authenc);
    282	struct aead_instance *inst = aead_alg_instance(authenc);
    283	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
    284	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
    285	struct crypto_ahash *auth = ctx->auth;
    286	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
    287	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
    288	u8 *hash = areq_ctx->tail;
    289	int err;
    290
    291	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
    292			   crypto_ahash_alignmask(auth) + 1);
    293
    294	ahash_request_set_tfm(ahreq, auth);
    295	ahash_request_set_crypt(ahreq, req->src, hash,
    296				req->assoclen + req->cryptlen - authsize);
    297	ahash_request_set_callback(ahreq, aead_request_flags(req),
    298				   authenc_verify_ahash_done, req);
    299
    300	err = crypto_ahash_digest(ahreq);
    301	if (err)
    302		return err;
    303
    304	return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
    305}
    306
    307static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
    308{
    309	struct aead_instance *inst = aead_alg_instance(tfm);
    310	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
    311	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
    312	struct crypto_ahash *auth;
    313	struct crypto_skcipher *enc;
    314	struct crypto_sync_skcipher *null;
    315	int err;
    316
    317	auth = crypto_spawn_ahash(&ictx->auth);
    318	if (IS_ERR(auth))
    319		return PTR_ERR(auth);
    320
    321	enc = crypto_spawn_skcipher(&ictx->enc);
    322	err = PTR_ERR(enc);
    323	if (IS_ERR(enc))
    324		goto err_free_ahash;
    325
    326	null = crypto_get_default_null_skcipher();
    327	err = PTR_ERR(null);
    328	if (IS_ERR(null))
    329		goto err_free_skcipher;
    330
    331	ctx->auth = auth;
    332	ctx->enc = enc;
    333	ctx->null = null;
    334
    335	crypto_aead_set_reqsize(
    336		tfm,
    337		sizeof(struct authenc_request_ctx) +
    338		ictx->reqoff +
    339		max_t(unsigned int,
    340		      crypto_ahash_reqsize(auth) +
    341		      sizeof(struct ahash_request),
    342		      sizeof(struct skcipher_request) +
    343		      crypto_skcipher_reqsize(enc)));
    344
    345	return 0;
    346
    347err_free_skcipher:
    348	crypto_free_skcipher(enc);
    349err_free_ahash:
    350	crypto_free_ahash(auth);
    351	return err;
    352}
    353
    354static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
    355{
    356	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
    357
    358	crypto_free_ahash(ctx->auth);
    359	crypto_free_skcipher(ctx->enc);
    360	crypto_put_default_null_skcipher();
    361}
    362
    363static void crypto_authenc_free(struct aead_instance *inst)
    364{
    365	struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);
    366
    367	crypto_drop_skcipher(&ctx->enc);
    368	crypto_drop_ahash(&ctx->auth);
    369	kfree(inst);
    370}
    371
    372static int crypto_authenc_create(struct crypto_template *tmpl,
    373				 struct rtattr **tb)
    374{
    375	u32 mask;
    376	struct aead_instance *inst;
    377	struct authenc_instance_ctx *ctx;
    378	struct hash_alg_common *auth;
    379	struct crypto_alg *auth_base;
    380	struct skcipher_alg *enc;
    381	int err;
    382
    383	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
    384	if (err)
    385		return err;
    386
    387	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
    388	if (!inst)
    389		return -ENOMEM;
    390	ctx = aead_instance_ctx(inst);
    391
    392	err = crypto_grab_ahash(&ctx->auth, aead_crypto_instance(inst),
    393				crypto_attr_alg_name(tb[1]), 0, mask);
    394	if (err)
    395		goto err_free_inst;
    396	auth = crypto_spawn_ahash_alg(&ctx->auth);
    397	auth_base = &auth->base;
    398
    399	err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),
    400				   crypto_attr_alg_name(tb[2]), 0, mask);
    401	if (err)
    402		goto err_free_inst;
    403	enc = crypto_spawn_skcipher_alg(&ctx->enc);
    404
    405	ctx->reqoff = ALIGN(2 * auth->digestsize + auth_base->cra_alignmask,
    406			    auth_base->cra_alignmask + 1);
    407
    408	err = -ENAMETOOLONG;
    409	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
    410		     "authenc(%s,%s)", auth_base->cra_name,
    411		     enc->base.cra_name) >=
    412	    CRYPTO_MAX_ALG_NAME)
    413		goto err_free_inst;
    414
    415	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
    416		     "authenc(%s,%s)", auth_base->cra_driver_name,
    417		     enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
    418		goto err_free_inst;
    419
    420	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
    421				      auth_base->cra_priority;
    422	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
    423	inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
    424				       enc->base.cra_alignmask;
    425	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
    426
    427	inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
    428	inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
    429	inst->alg.maxauthsize = auth->digestsize;
    430
    431	inst->alg.init = crypto_authenc_init_tfm;
    432	inst->alg.exit = crypto_authenc_exit_tfm;
    433
    434	inst->alg.setkey = crypto_authenc_setkey;
    435	inst->alg.encrypt = crypto_authenc_encrypt;
    436	inst->alg.decrypt = crypto_authenc_decrypt;
    437
    438	inst->free = crypto_authenc_free;
    439
    440	err = aead_register_instance(tmpl, inst);
    441	if (err) {
    442err_free_inst:
    443		crypto_authenc_free(inst);
    444	}
    445	return err;
    446}
    447
    448static struct crypto_template crypto_authenc_tmpl = {
    449	.name = "authenc",
    450	.create = crypto_authenc_create,
    451	.module = THIS_MODULE,
    452};
    453
    454static int __init crypto_authenc_module_init(void)
    455{
    456	return crypto_register_template(&crypto_authenc_tmpl);
    457}
    458
    459static void __exit crypto_authenc_module_exit(void)
    460{
    461	crypto_unregister_template(&crypto_authenc_tmpl);
    462}
    463
    464subsys_initcall(crypto_authenc_module_init);
    465module_exit(crypto_authenc_module_exit);
    466
    467MODULE_LICENSE("GPL");
    468MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
    469MODULE_ALIAS_CRYPTO("authenc");