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linux/crypto/authencesn.c
James Yonan 6bf37e5aa9 crypto: crypto_memneq - add equality testing of memory regions w/o timing leaks 
When comparing MAC hashes, AEAD authentication tags, or other hash
values in the context of authentication or integrity checking, it
is important not to leak timing information to a potential attacker,
i.e. when communication happens over a network.

Bytewise memory comparisons (such as memcmp) are usually optimized so
that they return a nonzero value as soon as a mismatch is found. E.g,
on x86_64/i5 for 512 bytes this can be ~50 cyc for a full mismatch
and up to ~850 cyc for a full match (cold). This early-return behavior
can leak timing information as a side channel, allowing an attacker to
iteratively guess the correct result.

This patch adds a new method crypto_memneq ("memory not equal to each
other") to the crypto API that compares memory areas of the same length
in roughly "constant time" (cache misses could change the timing, but
since they don't reveal information about the content of the strings
being compared, they are effectively benign). Iow, best and worst case
behaviour take the same amount of time to complete (in contrast to
memcmp).

Note that crypto_memneq (unlike memcmp) can only be used to test for
equality or inequality, NOT for lexicographical order. This, however,
is not an issue for its use-cases within the crypto API.

We tried to locate all of the places in the crypto API where memcmp was
being used for authentication or integrity checking, and convert them
over to crypto_memneq.

crypto_memneq is declared noinline, placed in its own source file,
and compiled with optimizations that might increase code size disabled
("Os") because a smart compiler (or LTO) might notice that the return
value is always compared against zero/nonzero, and might then
reintroduce the same early-return optimization that we are trying to
avoid.

Using #pragma or __attribute__ optimization annotations of the code
for disabling optimization was avoided as it seems to be considered
broken or unmaintained for long time in GCC [1]. Therefore, we work
around that by specifying the compile flag for memneq.o directly in
the Makefile. We found that this seems to be most appropriate.

As we use ("Os"), this patch also provides a loop-free "fast-path" for
frequently used 16 byte digests. Similarly to kernel library string
functions, leave an option for future even further optimized architecture
specific assembler implementations.

This was a joint work of James Yonan and Daniel Borkmann. Also thanks
for feedback from Florian Weimer on this and earlier proposals [2].

  [1] http://gcc.gnu.org/ml/gcc/2012-07/msg00211.html
  [2] https://lkml.org/lkml/2013/2/10/131

Signed-off-by: James Yonan <james@openvpn.net>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-10-07 14:17:06 +08:00

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/*
* 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>
*
* 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/aead.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/skcipher.h>
#include <crypto/authenc.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_ablkcipher *enc;
};
struct authenc_esn_request_ctx {
unsigned int cryptlen;
unsigned int headlen;
unsigned int trailen;
struct scatterlist *sg;
struct scatterlist hsg[2];
struct scatterlist tsg[1];
struct scatterlist cipher[2];
crypto_completion_t complete;
crypto_completion_t update_complete;
crypto_completion_t update_complete2;
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_setkey(struct crypto_aead *authenc_esn, const u8 *key,
unsigned int keylen)
{
unsigned int authkeylen;
unsigned int enckeylen;
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
struct crypto_ahash *auth = ctx->auth;
struct crypto_ablkcipher *enc = ctx->enc;
struct rtattr *rta = (void *)key;
struct crypto_authenc_key_param *param;
int err = -EINVAL;
if (!RTA_OK(rta, keylen))
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_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, key, authkeylen);
crypto_aead_set_flags(authenc_esn, 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_esn) &
CRYPTO_TFM_REQ_MASK);
err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
crypto_aead_set_flags(authenc_esn, crypto_ablkcipher_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 void authenc_esn_geniv_ahash_update_done(struct crypto_async_request *areq,
int err)
{
struct aead_request *req = areq->data;
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 ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
if (err)
goto out;
ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
areq_ctx->cryptlen);
ahash_request_set_callback(ahreq, aead_request_flags(req) &
CRYPTO_TFM_REQ_MAY_SLEEP,
areq_ctx->update_complete2, req);
err = crypto_ahash_update(ahreq);
if (err)
goto out;
ahash_request_set_crypt(ahreq, areq_ctx->tsg, ahreq->result,
areq_ctx->trailen);
ahash_request_set_callback(ahreq, aead_request_flags(req) &
CRYPTO_TFM_REQ_MAY_SLEEP,
areq_ctx->complete, req);
err = crypto_ahash_finup(ahreq);
if (err)
goto out;
scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
areq_ctx->cryptlen,
crypto_aead_authsize(authenc_esn), 1);
out:
authenc_esn_request_complete(req, err);
}
static void authenc_esn_geniv_ahash_update_done2(struct crypto_async_request *areq,
int err)
{
struct aead_request *req = areq->data;
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 ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
if (err)
goto out;
ahash_request_set_crypt(ahreq, areq_ctx->tsg, ahreq->result,
areq_ctx->trailen);
ahash_request_set_callback(ahreq, aead_request_flags(req) &
CRYPTO_TFM_REQ_MAY_SLEEP,
areq_ctx->complete, req);
err = crypto_ahash_finup(ahreq);
if (err)
goto out;
scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
areq_ctx->cryptlen,
crypto_aead_authsize(authenc_esn), 1);
out:
authenc_esn_request_complete(req, err);
}
static void authenc_esn_geniv_ahash_done(struct crypto_async_request *areq,
int err)
{
struct aead_request *req = areq->data;
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 ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
if (err)
goto out;
scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
areq_ctx->cryptlen,
crypto_aead_authsize(authenc_esn), 1);
out:
aead_request_complete(req, err);
}
static void authenc_esn_verify_ahash_update_done(struct crypto_async_request *areq,
int err)
{
u8 *ihash;
unsigned int authsize;
struct ablkcipher_request *abreq;
struct aead_request *req = areq->data;
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 ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
unsigned int cryptlen = req->cryptlen;
if (err)
goto out;
ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
areq_ctx->cryptlen);
ahash_request_set_callback(ahreq,
aead_request_flags(req) &
CRYPTO_TFM_REQ_MAY_SLEEP,
areq_ctx->update_complete2, req);
err = crypto_ahash_update(ahreq);
if (err)
goto out;
ahash_request_set_crypt(ahreq, areq_ctx->tsg, ahreq->result,
areq_ctx->trailen);
ahash_request_set_callback(ahreq, aead_request_flags(req) &
CRYPTO_TFM_REQ_MAY_SLEEP,
areq_ctx->complete, req);
err = crypto_ahash_finup(ahreq);
if (err)
goto out;
authsize = crypto_aead_authsize(authenc_esn);
cryptlen -= authsize;
ihash = ahreq->result + authsize;
scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
authsize, 0);
err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
if (err)
goto out;
abreq = aead_request_ctx(req);
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, req->src, req->dst,
cryptlen, req->iv);
err = crypto_ablkcipher_decrypt(abreq);
out:
authenc_esn_request_complete(req, err);
}
static void authenc_esn_verify_ahash_update_done2(struct crypto_async_request *areq,
int err)
{
u8 *ihash;
unsigned int authsize;
struct ablkcipher_request *abreq;
struct aead_request *req = areq->data;
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 ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
unsigned int cryptlen = req->cryptlen;
if (err)
goto out;
ahash_request_set_crypt(ahreq, areq_ctx->tsg, ahreq->result,
areq_ctx->trailen);
ahash_request_set_callback(ahreq, aead_request_flags(req) &
CRYPTO_TFM_REQ_MAY_SLEEP,
areq_ctx->complete, req);
err = crypto_ahash_finup(ahreq);
if (err)
goto out;
authsize = crypto_aead_authsize(authenc_esn);
cryptlen -= authsize;
ihash = ahreq->result + authsize;
scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
authsize, 0);
err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
if (err)
goto out;
abreq = aead_request_ctx(req);
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, req->src, req->dst,
cryptlen, req->iv);
err = crypto_ablkcipher_decrypt(abreq);
out:
authenc_esn_request_complete(req, err);
}
static void authenc_esn_verify_ahash_done(struct crypto_async_request *areq,
int err)
{
u8 *ihash;
unsigned int authsize;
struct ablkcipher_request *abreq;
struct aead_request *req = areq->data;
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 ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
unsigned int cryptlen = req->cryptlen;
if (err)
goto out;
authsize = crypto_aead_authsize(authenc_esn);
cryptlen -= authsize;
ihash = ahreq->result + authsize;
scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
authsize, 0);
err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
if (err)
goto out;
abreq = aead_request_ctx(req);
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, req->src, req->dst,
cryptlen, req->iv);
err = crypto_ablkcipher_decrypt(abreq);
out:
authenc_esn_request_complete(req, err);
}
static u8 *crypto_authenc_esn_ahash(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 crypto_ahash *auth = ctx->auth;
struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->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);
err = crypto_ahash_init(ahreq);
if (err)
return ERR_PTR(err);
ahash_request_set_crypt(ahreq, areq_ctx->hsg, hash, areq_ctx->headlen);
ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
areq_ctx->update_complete, req);
err = crypto_ahash_update(ahreq);
if (err)
return ERR_PTR(err);
ahash_request_set_crypt(ahreq, areq_ctx->sg, hash, areq_ctx->cryptlen);
ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
areq_ctx->update_complete2, req);
err = crypto_ahash_update(ahreq);
if (err)
return ERR_PTR(err);
ahash_request_set_crypt(ahreq, areq_ctx->tsg, hash,
areq_ctx->trailen);
ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
areq_ctx->complete, req);
err = crypto_ahash_finup(ahreq);
if (err)
return ERR_PTR(err);
return hash;
}
static int crypto_authenc_esn_genicv(struct aead_request *req, u8 *iv,
unsigned int flags)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
struct scatterlist *dst = req->dst;
struct scatterlist *assoc = req->assoc;
struct scatterlist *cipher = areq_ctx->cipher;
struct scatterlist *hsg = areq_ctx->hsg;
struct scatterlist *tsg = areq_ctx->tsg;
struct scatterlist *assoc1;
struct scatterlist *assoc2;
unsigned int ivsize = crypto_aead_ivsize(authenc_esn);
unsigned int cryptlen = req->cryptlen;
struct page *dstp;
u8 *vdst;
u8 *hash;
dstp = sg_page(dst);
vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
if (ivsize) {
sg_init_table(cipher, 2);
sg_set_buf(cipher, iv, ivsize);
scatterwalk_crypto_chain(cipher, dst, vdst == iv + ivsize, 2);
dst = cipher;
cryptlen += ivsize;
}
if (sg_is_last(assoc))
return -EINVAL;
assoc1 = assoc + 1;
if (sg_is_last(assoc1))
return -EINVAL;
assoc2 = assoc + 2;
if (!sg_is_last(assoc2))
return -EINVAL;
sg_init_table(hsg, 2);
sg_set_page(hsg, sg_page(assoc), assoc->length, assoc->offset);
sg_set_page(hsg + 1, sg_page(assoc2), assoc2->length, assoc2->offset);
sg_init_table(tsg, 1);
sg_set_page(tsg, sg_page(assoc1), assoc1->length, assoc1->offset);
areq_ctx->cryptlen = cryptlen;
areq_ctx->headlen = assoc->length + assoc2->length;
areq_ctx->trailen = assoc1->length;
areq_ctx->sg = dst;
areq_ctx->complete = authenc_esn_geniv_ahash_done;
areq_ctx->update_complete = authenc_esn_geniv_ahash_update_done;
areq_ctx->update_complete2 = authenc_esn_geniv_ahash_update_done2;
hash = crypto_authenc_esn_ahash(req, flags);
if (IS_ERR(hash))
return PTR_ERR(hash);
scatterwalk_map_and_copy(hash, dst, cryptlen,
crypto_aead_authsize(authenc_esn), 1);
return 0;
}
static void crypto_authenc_esn_encrypt_done(struct crypto_async_request *req,
int err)
{
struct aead_request *areq = req->data;
if (!err) {
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(areq);
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
struct ablkcipher_request *abreq = aead_request_ctx(areq);
u8 *iv = (u8 *)(abreq + 1) +
crypto_ablkcipher_reqsize(ctx->enc);
err = crypto_authenc_esn_genicv(areq, iv, 0);
}
authenc_esn_request_complete(areq, err);
}
static int crypto_authenc_esn_encrypt(struct aead_request *req)
{
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_ablkcipher *enc = ctx->enc;
struct scatterlist *dst = req->dst;
unsigned int cryptlen = req->cryptlen;
struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
+ ctx->reqoff);
u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
int err;
ablkcipher_request_set_tfm(abreq, enc);
ablkcipher_request_set_callback(abreq, aead_request_flags(req),
crypto_authenc_esn_encrypt_done, req);
ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
memcpy(iv, req->iv, crypto_aead_ivsize(authenc_esn));
err = crypto_ablkcipher_encrypt(abreq);
if (err)
return err;
return crypto_authenc_esn_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
}
static void crypto_authenc_esn_givencrypt_done(struct crypto_async_request *req,
int err)
{
struct aead_request *areq = req->data;
if (!err) {
struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
err = crypto_authenc_esn_genicv(areq, greq->giv, 0);
}
authenc_esn_request_complete(areq, err);
}
static int crypto_authenc_esn_givencrypt(struct aead_givcrypt_request *req)
{
struct crypto_aead *authenc_esn = aead_givcrypt_reqtfm(req);
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
struct aead_request *areq = &req->areq;
struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
u8 *iv = req->giv;
int err;
skcipher_givcrypt_set_tfm(greq, ctx->enc);
skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
crypto_authenc_esn_givencrypt_done, areq);
skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
areq->iv);
skcipher_givcrypt_set_giv(greq, iv, req->seq);
err = crypto_skcipher_givencrypt(greq);
if (err)
return err;
return crypto_authenc_esn_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
}
static int crypto_authenc_esn_verify(struct aead_request *req)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
u8 *ohash;
u8 *ihash;
unsigned int authsize;
areq_ctx->complete = authenc_esn_verify_ahash_done;
areq_ctx->update_complete = authenc_esn_verify_ahash_update_done;
ohash = crypto_authenc_esn_ahash(req, CRYPTO_TFM_REQ_MAY_SLEEP);
if (IS_ERR(ohash))
return PTR_ERR(ohash);
authsize = crypto_aead_authsize(authenc_esn);
ihash = ohash + authsize;
scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
authsize, 0);
return crypto_memneq(ihash, ohash, authsize) ? -EBADMSG : 0;
}
static int crypto_authenc_esn_iverify(struct aead_request *req, u8 *iv,
unsigned int cryptlen)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
struct scatterlist *src = req->src;
struct scatterlist *assoc = req->assoc;
struct scatterlist *cipher = areq_ctx->cipher;
struct scatterlist *hsg = areq_ctx->hsg;
struct scatterlist *tsg = areq_ctx->tsg;
struct scatterlist *assoc1;
struct scatterlist *assoc2;
unsigned int ivsize = crypto_aead_ivsize(authenc_esn);
struct page *srcp;
u8 *vsrc;
srcp = sg_page(src);
vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
if (ivsize) {
sg_init_table(cipher, 2);
sg_set_buf(cipher, iv, ivsize);
scatterwalk_crypto_chain(cipher, src, vsrc == iv + ivsize, 2);
src = cipher;
cryptlen += ivsize;
}
if (sg_is_last(assoc))
return -EINVAL;
assoc1 = assoc + 1;
if (sg_is_last(assoc1))
return -EINVAL;
assoc2 = assoc + 2;
if (!sg_is_last(assoc2))
return -EINVAL;
sg_init_table(hsg, 2);
sg_set_page(hsg, sg_page(assoc), assoc->length, assoc->offset);
sg_set_page(hsg + 1, sg_page(assoc2), assoc2->length, assoc2->offset);
sg_init_table(tsg, 1);
sg_set_page(tsg, sg_page(assoc1), assoc1->length, assoc1->offset);
areq_ctx->cryptlen = cryptlen;
areq_ctx->headlen = assoc->length + assoc2->length;
areq_ctx->trailen = assoc1->length;
areq_ctx->sg = src;
areq_ctx->complete = authenc_esn_verify_ahash_done;
areq_ctx->update_complete = authenc_esn_verify_ahash_update_done;
areq_ctx->update_complete2 = authenc_esn_verify_ahash_update_done2;
return crypto_authenc_esn_verify(req);
}
static int crypto_authenc_esn_decrypt(struct aead_request *req)
{
struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
struct ablkcipher_request *abreq = aead_request_ctx(req);
unsigned int cryptlen = req->cryptlen;
unsigned int authsize = crypto_aead_authsize(authenc_esn);
u8 *iv = req->iv;
int err;
if (cryptlen < authsize)
return -EINVAL;
cryptlen -= authsize;
err = crypto_authenc_esn_iverify(req, iv, cryptlen);
if (err)
return err;
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, req->src, req->dst, cryptlen, iv);
return crypto_ablkcipher_decrypt(abreq);
}
static int crypto_authenc_esn_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
struct authenc_esn_instance_ctx *ictx = crypto_instance_ctx(inst);
struct crypto_authenc_esn_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_ahash *auth;
struct crypto_ablkcipher *enc;
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;
ctx->auth = auth;
ctx->enc = enc;
ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
crypto_ahash_alignmask(auth),
crypto_ahash_alignmask(auth) + 1) +
crypto_ablkcipher_ivsize(enc);
tfm->crt_aead.reqsize = sizeof(struct authenc_esn_request_ctx) +
ctx->reqoff +
max_t(unsigned int,
crypto_ahash_reqsize(auth) +
sizeof(struct ahash_request),
sizeof(struct skcipher_givcrypt_request) +
crypto_ablkcipher_reqsize(enc));
return 0;
err_free_ahash:
crypto_free_ahash(auth);
return err;
}
static void crypto_authenc_esn_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_authenc_esn_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_ahash(ctx->auth);
crypto_free_ablkcipher(ctx->enc);
}
static struct crypto_instance *crypto_authenc_esn_alloc(struct rtattr **tb)
{
struct crypto_attr_type *algt;
struct crypto_instance *inst;
struct hash_alg_common *auth;
struct crypto_alg *auth_base;
struct crypto_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 ERR_CAST(algt);
if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
return ERR_PTR(-EINVAL);
auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
CRYPTO_ALG_TYPE_AHASH_MASK);
if (IS_ERR(auth))
return ERR_CAST(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 = crypto_instance_ctx(inst);
err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
if (err)
goto err_free_inst;
crypto_set_skcipher_spawn(&ctx->enc, 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);
err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
"authencesn(%s,%s)", auth_base->cra_name, enc->cra_name) >=
CRYPTO_MAX_ALG_NAME)
goto err_drop_enc;
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"authencesn(%s,%s)", auth_base->cra_driver_name,
enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto err_drop_enc;
inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.cra_priority = enc->cra_priority *
10 + auth_base->cra_priority;
inst->alg.cra_blocksize = enc->cra_blocksize;
inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
inst->alg.cra_type = &crypto_aead_type;
inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
inst->alg.cra_aead.maxauthsize = auth->digestsize;
inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_esn_ctx);
inst->alg.cra_init = crypto_authenc_esn_init_tfm;
inst->alg.cra_exit = crypto_authenc_esn_exit_tfm;
inst->alg.cra_aead.setkey = crypto_authenc_esn_setkey;
inst->alg.cra_aead.encrypt = crypto_authenc_esn_encrypt;
inst->alg.cra_aead.decrypt = crypto_authenc_esn_decrypt;
inst->alg.cra_aead.givencrypt = crypto_authenc_esn_givencrypt;
out:
crypto_mod_put(auth_base);
return inst;
err_drop_enc:
crypto_drop_skcipher(&ctx->enc);
err_drop_auth:
crypto_drop_ahash(&ctx->auth);
err_free_inst:
kfree(inst);
out_put_auth:
inst = ERR_PTR(err);
goto out;
}
static void crypto_authenc_esn_free(struct crypto_instance *inst)
{
struct authenc_esn_instance_ctx *ctx = crypto_instance_ctx(inst);
crypto_drop_skcipher(&ctx->enc);
crypto_drop_ahash(&ctx->auth);
kfree(inst);
}
static struct crypto_template crypto_authenc_esn_tmpl = {
.name = "authencesn",
.alloc = crypto_authenc_esn_alloc,
.free = crypto_authenc_esn_free,
.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");
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