linux-stable/crypto/authencesn.c
Herbert Xu 41cdf7a453 crypto: authencesn - Fix digest_null crash
When authencesn is used together with digest_null a crash will
occur on the decrypt path.  This is because normally we perform
a special setup to preserve the ESN, but this is skipped if there
is no authentication.  However, on the post-authentication path
it always expects the preservation to be in place, thus causing
a crash when digest_null is used.

This patch fixes this by also skipping the post-processing when
there is no authentication.

Fixes: 104880a6b4 ("crypto: authencesn - Convert to new AEAD...")
Cc: <stable@vger.kernel.org>
Reported-by: Jan Tluka <jtluka@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-07-18 17:01:11 +08:00

531 lines
15 KiB
C

/*
* authencesn.c - AEAD wrapper for IPsec with extended sequence numbers,
* derived from authenc.c
*
* Copyright (C) 2010 secunet Security Networks AG
* Copyright (C) 2010 Steffen Klassert <steffen.klassert@secunet.com>
* Copyright (c) 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_esn_instance_ctx {
struct crypto_ahash_spawn auth;
struct crypto_skcipher_spawn enc;
};
struct crypto_authenc_esn_ctx {
unsigned int reqoff;
struct crypto_ahash *auth;
struct crypto_skcipher *enc;
struct crypto_skcipher *null;
};
struct authenc_esn_request_ctx {
struct scatterlist src[2];
struct scatterlist dst[2];
char tail[];
};
static void authenc_esn_request_complete(struct aead_request *req, int err)
{
if (err != -EINPROGRESS)
aead_request_complete(req, err);
}
static int crypto_authenc_esn_setauthsize(struct crypto_aead *authenc_esn,
unsigned int authsize)
{
if (authsize > 0 && authsize < 4)
return -EINVAL;
return 0;
}
static int crypto_authenc_esn_setkey(struct crypto_aead *authenc_esn, const u8 *key,
unsigned int keylen)
{
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
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_esn) &
CRYPTO_TFM_REQ_MASK);
err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
crypto_aead_set_flags(authenc_esn, 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_esn) &
CRYPTO_TFM_REQ_MASK);
err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
crypto_aead_set_flags(authenc_esn, crypto_skcipher_get_flags(enc) &
CRYPTO_TFM_RES_MASK);
out:
return err;
badkey:
crypto_aead_set_flags(authenc_esn, CRYPTO_TFM_RES_BAD_KEY_LEN);
goto out;
}
static int crypto_authenc_esn_genicv_tail(struct aead_request *req,
unsigned int flags)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
struct crypto_ahash *auth = ctx->auth;
u8 *hash = PTR_ALIGN((u8 *)areq_ctx->tail,
crypto_ahash_alignmask(auth) + 1);
unsigned int authsize = crypto_aead_authsize(authenc_esn);
unsigned int assoclen = req->assoclen;
unsigned int cryptlen = req->cryptlen;
struct scatterlist *dst = req->dst;
u32 tmp[2];
/* Move high-order bits of sequence number back. */
scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);
scatterwalk_map_and_copy(hash, dst, assoclen + cryptlen, authsize, 1);
return 0;
}
static void authenc_esn_geniv_ahash_done(struct crypto_async_request *areq,
int err)
{
struct aead_request *req = areq->data;
err = err ?: crypto_authenc_esn_genicv_tail(req, 0);
aead_request_complete(req, err);
}
static int crypto_authenc_esn_genicv(struct aead_request *req,
unsigned int flags)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
struct crypto_ahash *auth = ctx->auth;
u8 *hash = PTR_ALIGN((u8 *)areq_ctx->tail,
crypto_ahash_alignmask(auth) + 1);
struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
unsigned int authsize = crypto_aead_authsize(authenc_esn);
unsigned int assoclen = req->assoclen;
unsigned int cryptlen = req->cryptlen;
struct scatterlist *dst = req->dst;
u32 tmp[2];
if (!authsize)
return 0;
/* Move high-order bits of sequence number to the end. */
scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);
sg_init_table(areq_ctx->dst, 2);
dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
ahash_request_set_tfm(ahreq, auth);
ahash_request_set_crypt(ahreq, dst, hash, assoclen + cryptlen);
ahash_request_set_callback(ahreq, flags,
authenc_esn_geniv_ahash_done, req);
return crypto_ahash_digest(ahreq) ?:
crypto_authenc_esn_genicv_tail(req, aead_request_flags(req));
}
static void crypto_authenc_esn_encrypt_done(struct crypto_async_request *req,
int err)
{
struct aead_request *areq = req->data;
if (!err)
err = crypto_authenc_esn_genicv(areq, 0);
authenc_esn_request_complete(areq, err);
}
static int crypto_authenc_esn_copy(struct aead_request *req, unsigned int len)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
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, len, NULL);
return crypto_skcipher_encrypt(skreq);
}
static int crypto_authenc_esn_encrypt(struct aead_request *req)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
struct skcipher_request *skreq = (void *)(areq_ctx->tail +
ctx->reqoff);
struct crypto_skcipher *enc = ctx->enc;
unsigned int assoclen = req->assoclen;
unsigned int cryptlen = req->cryptlen;
struct scatterlist *src, *dst;
int err;
sg_init_table(areq_ctx->src, 2);
src = scatterwalk_ffwd(areq_ctx->src, req->src, assoclen);
dst = src;
if (req->src != req->dst) {
err = crypto_authenc_esn_copy(req, assoclen);
if (err)
return err;
sg_init_table(areq_ctx->dst, 2);
dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, assoclen);
}
skcipher_request_set_tfm(skreq, enc);
skcipher_request_set_callback(skreq, aead_request_flags(req),
crypto_authenc_esn_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_esn_genicv(req, aead_request_flags(req));
}
static int crypto_authenc_esn_decrypt_tail(struct aead_request *req,
unsigned int flags)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
unsigned int authsize = crypto_aead_authsize(authenc_esn);
struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
struct skcipher_request *skreq = (void *)(areq_ctx->tail +
ctx->reqoff);
struct crypto_ahash *auth = ctx->auth;
u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail,
crypto_ahash_alignmask(auth) + 1);
unsigned int cryptlen = req->cryptlen - authsize;
unsigned int assoclen = req->assoclen;
struct scatterlist *dst = req->dst;
u8 *ihash = ohash + crypto_ahash_digestsize(auth);
u32 tmp[2];
if (!authsize)
goto decrypt;
/* Move high-order bits of sequence number back. */
scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);
if (crypto_memneq(ihash, ohash, authsize))
return -EBADMSG;
decrypt:
sg_init_table(areq_ctx->dst, 2);
dst = scatterwalk_ffwd(areq_ctx->dst, dst, 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, dst, dst, cryptlen, req->iv);
return crypto_skcipher_decrypt(skreq);
}
static void authenc_esn_verify_ahash_done(struct crypto_async_request *areq,
int err)
{
struct aead_request *req = areq->data;
err = err ?: crypto_authenc_esn_decrypt_tail(req, 0);
aead_request_complete(req, err);
}
static int crypto_authenc_esn_decrypt(struct aead_request *req)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
unsigned int authsize = crypto_aead_authsize(authenc_esn);
struct crypto_ahash *auth = ctx->auth;
u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail,
crypto_ahash_alignmask(auth) + 1);
unsigned int assoclen = req->assoclen;
unsigned int cryptlen = req->cryptlen;
u8 *ihash = ohash + crypto_ahash_digestsize(auth);
struct scatterlist *dst = req->dst;
u32 tmp[2];
int err;
cryptlen -= authsize;
if (req->src != dst) {
err = crypto_authenc_esn_copy(req, assoclen + cryptlen);
if (err)
return err;
}
scatterwalk_map_and_copy(ihash, req->src, assoclen + cryptlen,
authsize, 0);
if (!authsize)
goto tail;
/* Move high-order bits of sequence number to the end. */
scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);
sg_init_table(areq_ctx->dst, 2);
dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
ahash_request_set_tfm(ahreq, auth);
ahash_request_set_crypt(ahreq, dst, ohash, assoclen + cryptlen);
ahash_request_set_callback(ahreq, aead_request_flags(req),
authenc_esn_verify_ahash_done, req);
err = crypto_ahash_digest(ahreq);
if (err)
return err;
tail:
return crypto_authenc_esn_decrypt_tail(req, aead_request_flags(req));
}
static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm)
{
struct aead_instance *inst = aead_alg_instance(tfm);
struct authenc_esn_instance_ctx *ictx = aead_instance_ctx(inst);
struct crypto_authenc_esn_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_skcipher2();
err = PTR_ERR(null);
if (IS_ERR(null))
goto err_free_skcipher;
ctx->auth = auth;
ctx->enc = enc;
ctx->null = null;
ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth),
crypto_ahash_alignmask(auth) + 1);
crypto_aead_set_reqsize(
tfm,
sizeof(struct authenc_esn_request_ctx) +
ctx->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_esn_exit_tfm(struct crypto_aead *tfm)
{
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
crypto_free_ahash(ctx->auth);
crypto_free_skcipher(ctx->enc);
crypto_put_default_null_skcipher2();
}
static void crypto_authenc_esn_free(struct aead_instance *inst)
{
struct authenc_esn_instance_ctx *ctx = aead_instance_ctx(inst);
crypto_drop_skcipher(&ctx->enc);
crypto_drop_ahash(&ctx->auth);
kfree(inst);
}
static int crypto_authenc_esn_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_esn_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);
err = -ENAMETOOLONG;
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"authencesn(%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,
"authencesn(%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_esn_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_esn_init_tfm;
inst->alg.exit = crypto_authenc_esn_exit_tfm;
inst->alg.setkey = crypto_authenc_esn_setkey;
inst->alg.setauthsize = crypto_authenc_esn_setauthsize;
inst->alg.encrypt = crypto_authenc_esn_encrypt;
inst->alg.decrypt = crypto_authenc_esn_decrypt;
inst->free = crypto_authenc_esn_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_esn_tmpl = {
.name = "authencesn",
.create = crypto_authenc_esn_create,
.module = THIS_MODULE,
};
static int __init crypto_authenc_esn_module_init(void)
{
return crypto_register_template(&crypto_authenc_esn_tmpl);
}
static void __exit crypto_authenc_esn_module_exit(void)
{
crypto_unregister_template(&crypto_authenc_esn_tmpl);
}
module_init(crypto_authenc_esn_module_init);
module_exit(crypto_authenc_esn_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
MODULE_DESCRIPTION("AEAD wrapper for IPsec with extended sequence numbers");
MODULE_ALIAS_CRYPTO("authencesn");