linux/crypto/authencesn.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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>
*/
#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_sync_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)
crypto: remove CRYPTO_TFM_RES_BAD_KEY_LEN The CRYPTO_TFM_RES_BAD_KEY_LEN flag was apparently meant as a way to make the ->setkey() functions provide more information about errors. However, no one actually checks for this flag, which makes it pointless. Also, many algorithms fail to set this flag when given a bad length key. Reviewing just the generic implementations, this is the case for aes-fixed-time, cbcmac, echainiv, nhpoly1305, pcrypt, rfc3686, rfc4309, rfc7539, rfc7539esp, salsa20, seqiv, and xcbc. But there are probably many more in arch/*/crypto/ and drivers/crypto/. Some algorithms can even set this flag when the key is the correct length. For example, authenc and authencesn set it when the key payload is malformed in any way (not just a bad length), the atmel-sha and ccree drivers can set it if a memory allocation fails, and the chelsio driver sets it for bad auth tag lengths, not just bad key lengths. So even if someone actually wanted to start checking this flag (which seems unlikely, since it's been unused for a long time), there would be a lot of work needed to get it working correctly. But it would probably be much better to go back to the drawing board and just define different return values, like -EINVAL if the key is invalid for the algorithm vs. -EKEYREJECTED if the key was rejected by a policy like "no weak keys". That would be much simpler, less error-prone, and easier to test. So just remove this flag. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Horia Geantă <horia.geanta@nxp.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-12-31 03:19:36 +00:00
goto out;
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);
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);
out:
memzero_explicit(&keys, sizeof(keys));
return err;
}
static int crypto_authenc_esn_genicv_tail(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);
u8 *hash = areq_ctx->tail;
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(void *data, int err)
{
struct aead_request *req = 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 = areq_ctx->tail;
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(void *data, int err)
{
struct aead_request *areq = 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);
SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
skcipher_request_set_sync_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 = areq_ctx->tail;
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(void *data, int err)
{
struct aead_request *req = data;
err = err ?: crypto_authenc_esn_decrypt_tail(req, 0);
crypto: authencesn - Avoid twice completion call in decrypt path Authencesn template in decrypt path unconditionally calls aead_request_complete after ahash_verify which leads to following kernel panic in after decryption. [ 338.539800] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 [ 338.548372] PGD 0 P4D 0 [ 338.551157] Oops: 0000 [#1] SMP PTI [ 338.554919] CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Tainted: G W I 4.19.7+ #13 [ 338.564431] Hardware name: Supermicro X8ST3/X8ST3, BIOS 2.0 07/29/10 [ 338.572212] RIP: 0010:esp_input_done2+0x350/0x410 [esp4] [ 338.578030] Code: ff 0f b6 68 10 48 8b 83 c8 00 00 00 e9 8e fe ff ff 8b 04 25 04 00 00 00 83 e8 01 48 98 48 8b 3c c5 10 00 00 00 e9 f7 fd ff ff <8b> 04 25 04 00 00 00 83 e8 01 48 98 4c 8b 24 c5 10 00 00 00 e9 3b [ 338.598547] RSP: 0018:ffff911c97803c00 EFLAGS: 00010246 [ 338.604268] RAX: 0000000000000002 RBX: ffff911c4469ee00 RCX: 0000000000000000 [ 338.612090] RDX: 0000000000000000 RSI: 0000000000000130 RDI: ffff911b87c20400 [ 338.619874] RBP: 0000000000000000 R08: ffff911b87c20498 R09: 000000000000000a [ 338.627610] R10: 0000000000000001 R11: 0000000000000004 R12: 0000000000000000 [ 338.635402] R13: ffff911c89590000 R14: ffff911c91730000 R15: 0000000000000000 [ 338.643234] FS: 0000000000000000(0000) GS:ffff911c97800000(0000) knlGS:0000000000000000 [ 338.652047] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 338.658299] CR2: 0000000000000004 CR3: 00000001ec20a000 CR4: 00000000000006f0 [ 338.666382] Call Trace: [ 338.669051] <IRQ> [ 338.671254] esp_input_done+0x12/0x20 [esp4] [ 338.675922] chcr_handle_resp+0x3b5/0x790 [chcr] [ 338.680949] cpl_fw6_pld_handler+0x37/0x60 [chcr] [ 338.686080] chcr_uld_rx_handler+0x22/0x50 [chcr] [ 338.691233] uldrx_handler+0x8c/0xc0 [cxgb4] [ 338.695923] process_responses+0x2f0/0x5d0 [cxgb4] [ 338.701177] ? bitmap_find_next_zero_area_off+0x3a/0x90 [ 338.706882] ? matrix_alloc_area.constprop.7+0x60/0x90 [ 338.712517] ? apic_update_irq_cfg+0x82/0xf0 [ 338.717177] napi_rx_handler+0x14/0xe0 [cxgb4] [ 338.722015] net_rx_action+0x2aa/0x3e0 [ 338.726136] __do_softirq+0xcb/0x280 [ 338.730054] irq_exit+0xde/0xf0 [ 338.733504] do_IRQ+0x54/0xd0 [ 338.736745] common_interrupt+0xf/0xf Fixes: 104880a6b470 ("crypto: authencesn - Convert to new AEAD...") Signed-off-by: Harsh Jain <harsh@chelsio.com> Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-01-03 08:51:05 +00:00
authenc_esn_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 = areq_ctx->tail;
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_sync_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;
ctx->reqoff = 2 * crypto_ahash_digestsize(auth);
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_skcipher();
}
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)
{
u32 mask;
struct aead_instance *inst;
struct authenc_esn_instance_ctx *ctx;
struct skcipher_alg_common *enc;
struct hash_alg_common *auth;
struct crypto_alg *auth_base;
int err;
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
if (err)
return err;
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
if (!inst)
return -ENOMEM;
ctx = aead_instance_ctx(inst);
err = crypto_grab_ahash(&ctx->auth, aead_crypto_instance(inst),
crypto_attr_alg_name(tb[1]), 0, mask);
if (err)
goto err_free_inst;
auth = crypto_spawn_ahash_alg(&ctx->auth);
auth_base = &auth->base;
err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),
crypto_attr_alg_name(tb[2]), 0, mask);
if (err)
goto err_free_inst;
enc = crypto_spawn_skcipher_alg_common(&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_free_inst;
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_free_inst;
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 = enc->base.cra_alignmask;
inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_esn_ctx);
inst->alg.ivsize = enc->ivsize;
inst->alg.chunksize = enc->chunksize;
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) {
err_free_inst:
crypto_authenc_esn_free(inst);
}
return err;
}
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);
}
subsys_initcall(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");