linux/crypto/authenc.c
Herbert Xu 927ef32dcc crypto: authenc - Consider ahash ASYNC bit
As it is, if you get an async ahash with a sync skcipher you'll
end up with a sync authenc, which is wrong.

This patch fixes it by considering the ASYNC bit from ahash as
well.

It also fixes a little bug where if a sync version of authenc
is requested we may still end up using an async ahash.

Neither of them should have any effect as none of the authenc
users can request for a sync authenc.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-07-01 23:45:02 +08:00

503 lines
14 KiB
C

/*
* 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_ablkcipher *enc;
struct crypto_blkcipher *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;
if (RTA_PAYLOAD(rta) < sizeof(*param))
return -EINVAL;
param = RTA_DATA(rta);
keys->enckeylen = be32_to_cpu(param->enckeylen);
key += RTA_ALIGN(rta->rta_len);
keylen -= RTA_ALIGN(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_ablkcipher *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_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, keys.enckey, keys.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 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);
struct blkcipher_desc desc = {
.tfm = ctx->null,
};
return crypto_blkcipher_encrypt(&desc, req->dst, req->src,
req->assoclen);
}
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_ablkcipher *enc = ctx->enc;
unsigned int cryptlen = req->cryptlen;
struct ablkcipher_request *abreq = (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);
}
ablkcipher_request_set_tfm(abreq, enc);
ablkcipher_request_set_callback(abreq, aead_request_flags(req),
crypto_authenc_encrypt_done, req);
ablkcipher_request_set_crypt(abreq, src, dst, cryptlen, req->iv);
err = crypto_ablkcipher_encrypt(abreq);
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 ablkcipher_request *abreq = (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);
ablkcipher_request_set_tfm(abreq, ctx->enc);
ablkcipher_request_set_callback(abreq, aead_request_flags(req),
req->base.complete, req->base.data);
ablkcipher_request_set_crypt(abreq, src, dst,
req->cryptlen - authsize, req->iv);
return crypto_ablkcipher_decrypt(abreq);
}
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_ablkcipher *enc;
struct crypto_blkcipher *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 ablkcipher_request) +
crypto_ablkcipher_reqsize(enc)));
return 0;
err_free_skcipher:
crypto_free_ablkcipher(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_ablkcipher(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 crypto_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_skcipher_spawn_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->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->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto err_drop_enc;
inst->alg.base.cra_flags = (auth_base->cra_flags | enc->cra_flags) &
CRYPTO_ALG_ASYNC;
inst->alg.base.cra_priority = enc->cra_priority * 10 +
auth_base->cra_priority;
inst->alg.base.cra_blocksize = enc->cra_blocksize;
inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
enc->cra_alignmask;
inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
inst->alg.ivsize = enc->cra_ablkcipher.ivsize;
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");