| /* |
| * 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 <crypto/authenc.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> |
| |
| #include "scatterwalk.h" |
| |
| struct authenc_instance_ctx { |
| struct crypto_spawn auth; |
| struct crypto_spawn enc; |
| }; |
| |
| 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) |
| { |
| unsigned int authkeylen; |
| unsigned int enckeylen; |
| struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); |
| struct crypto_hash *auth = ctx->auth; |
| struct crypto_ablkcipher *enc = ctx->enc; |
| struct rtattr *rta = (void *)key; |
| struct crypto_authenc_key_param *param; |
| int err = -EINVAL; |
| |
| if (keylen < sizeof(*rta)) |
| goto badkey; |
| if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM) |
| goto badkey; |
| if (RTA_PAYLOAD(rta) < sizeof(*param)) |
| goto badkey; |
| |
| param = RTA_DATA(rta); |
| enckeylen = be32_to_cpu(param->enckeylen); |
| |
| key += RTA_ALIGN(rta->rta_len); |
| keylen -= RTA_ALIGN(rta->rta_len); |
| |
| if (keylen < enckeylen) |
| goto badkey; |
| |
| 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; |
| |
| badkey: |
| crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN); |
| goto out; |
| } |
| |
| static int crypto_authenc_hash(struct aead_request *req) |
| { |
| struct crypto_aead *authenc = crypto_aead_reqtfm(req); |
| 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 = req->dst; |
| unsigned int cryptlen = req->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; |
| |
| 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, |
| crypto_aead_authsize(authenc), 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, |
| unsigned int cryptlen) |
| { |
| struct crypto_aead *authenc = crypto_aead_reqtfm(req); |
| 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 = req->src; |
| 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; |
| |
| 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 = crypto_aead_authsize(authenc); |
| 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); |
| unsigned int cryptlen = req->cryptlen; |
| unsigned int authsize = crypto_aead_authsize(authenc); |
| int err; |
| |
| if (cryptlen < authsize) |
| return -EINVAL; |
| cryptlen -= authsize; |
| |
| err = crypto_authenc_verify(req, cryptlen); |
| 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, 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; |
| int err; |
| |
| auth = crypto_spawn_hash(&ictx->auth); |
| if (IS_ERR(auth)) |
| return PTR_ERR(auth); |
| |
| 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)) + |
| crypto_hash_digestsize(auth) * 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; |
| 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)); |
| |
| enc = crypto_attr_alg(tb[2], CRYPTO_ALG_TYPE_BLKCIPHER, |
| CRYPTO_ALG_TYPE_BLKCIPHER_MASK); |
| inst = ERR_PTR(PTR_ERR(enc)); |
| if (IS_ERR(enc)) |
| goto out_put_auth; |
| |
| 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,%s)", auth->cra_name, enc->cra_name) >= |
| CRYPTO_MAX_ALG_NAME) |
| goto err_free_inst; |
| |
| if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, |
| "authenc(%s,%s)", auth->cra_driver_name, |
| enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) |
| goto err_free_inst; |
| |
| ctx = crypto_instance_ctx(inst); |
| |
| 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 = 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.maxauthsize = auth->cra_type == &crypto_hash_type ? |
| auth->cra_hash.digestsize : |
| auth->cra_digest.dia_digestsize; |
| |
| 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"); |