| /* |
| * Authenc: Simple AEAD wrapper for IPsec |
| * |
| * Copyright (c) 2007-2015 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/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_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 crypto_skcipher *null; |
| }; |
| |
| 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) |
| 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 badkey; |
| |
| 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); |
| crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) & |
| CRYPTO_TFM_RES_MASK); |
| |
| 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); |
| crypto_aead_set_flags(authenc, crypto_skcipher_get_flags(enc) & |
| CRYPTO_TFM_RES_MASK); |
| |
| out: |
| memzero_explicit(&keys, sizeof(keys)); |
| return err; |
| |
| badkey: |
| crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN); |
| goto out; |
| } |
| |
| static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err) |
| { |
| struct aead_request *req = areq->data; |
| 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); |
| |
| if (err) |
| goto out; |
| |
| scatterwalk_map_and_copy(ahreq->result, req->dst, |
| req->assoclen + req->cryptlen, |
| crypto_aead_authsize(authenc), 1); |
| |
| out: |
| aead_request_complete(req, err); |
| } |
| |
| static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags) |
| { |
| 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); |
| u8 *hash = areq_ctx->tail; |
| int err; |
| |
| hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth), |
| crypto_ahash_alignmask(auth) + 1); |
| |
| ahash_request_set_tfm(ahreq, auth); |
| ahash_request_set_crypt(ahreq, req->dst, hash, |
| req->assoclen + req->cryptlen); |
| ahash_request_set_callback(ahreq, flags, |
| 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(struct crypto_async_request *req, |
| int err) |
| { |
| struct aead_request *areq = req->data; |
| |
| if (err) |
| goto out; |
| |
| err = crypto_authenc_genicv(areq, 0); |
| |
| out: |
| authenc_request_complete(areq, err); |
| } |
| |
| static int crypto_authenc_copy_assoc(struct aead_request *req) |
| { |
| struct crypto_aead *authenc = crypto_aead_reqtfm(req); |
| struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); |
| SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null); |
| |
| skcipher_request_set_tfm(skreq, ctx->null); |
| skcipher_request_set_callback(skreq, aead_request_flags(req), |
| NULL, NULL); |
| skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen, |
| NULL); |
| |
| return crypto_skcipher_encrypt(skreq); |
| } |
| |
| 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) { |
| err = crypto_authenc_copy_assoc(req); |
| if (err) |
| return err; |
| |
| 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, aead_request_flags(req)); |
| } |
| |
| static int crypto_authenc_decrypt_tail(struct aead_request *req, |
| unsigned int flags) |
| { |
| 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); |
| 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, |
| req->base.complete, 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(struct crypto_async_request *areq, |
| int err) |
| { |
| struct aead_request *req = areq->data; |
| |
| if (err) |
| goto out; |
| |
| err = crypto_authenc_decrypt_tail(req, 0); |
| |
| out: |
| 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; |
| |
| hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth), |
| crypto_ahash_alignmask(auth) + 1); |
| |
| 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, aead_request_flags(req)); |
| } |
| |
| 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; |
| struct crypto_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; |
| |
| 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_skcipher: |
| crypto_free_skcipher(enc); |
| 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); |
| crypto_put_default_null_skcipher(); |
| } |
| |
| 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) |
| { |
| struct crypto_attr_type *algt; |
| struct aead_instance *inst; |
| struct hash_alg_common *auth; |
| struct crypto_alg *auth_base; |
| struct skcipher_alg *enc; |
| struct authenc_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; |
| |
| auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH, |
| CRYPTO_ALG_TYPE_AHASH_MASK | |
| crypto_requires_sync(algt->type, algt->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; |
| |
| crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst)); |
| err = crypto_grab_skcipher(&ctx->enc, enc_name, 0, |
| crypto_requires_sync(algt->type, |
| algt->mask)); |
| if (err) |
| goto err_drop_auth; |
| |
| enc = crypto_spawn_skcipher_alg(&ctx->enc); |
| |
| ctx->reqoff = ALIGN(2 * auth->digestsize + auth_base->cra_alignmask, |
| auth_base->cra_alignmask + 1); |
| |
| 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_drop_enc; |
| |
| 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_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_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_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) |
| 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_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"); |