linux/crypto/blake2s_generic.c
Eric Biggers 674f368a95 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>
2020-01-09 11:30:53 +08:00

170 lines
5.0 KiB
C

// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
* Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#include <crypto/internal/blake2s.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/hash.h>
#include <linux/types.h>
#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/module.h>
static int crypto_blake2s_setkey(struct crypto_shash *tfm, const u8 *key,
unsigned int keylen)
{
struct blake2s_tfm_ctx *tctx = crypto_shash_ctx(tfm);
if (keylen == 0 || keylen > BLAKE2S_KEY_SIZE)
return -EINVAL;
memcpy(tctx->key, key, keylen);
tctx->keylen = keylen;
return 0;
}
static int crypto_blake2s_init(struct shash_desc *desc)
{
struct blake2s_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
struct blake2s_state *state = shash_desc_ctx(desc);
const int outlen = crypto_shash_digestsize(desc->tfm);
if (tctx->keylen)
blake2s_init_key(state, outlen, tctx->key, tctx->keylen);
else
blake2s_init(state, outlen);
return 0;
}
static int crypto_blake2s_update(struct shash_desc *desc, const u8 *in,
unsigned int inlen)
{
struct blake2s_state *state = shash_desc_ctx(desc);
const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
if (unlikely(!inlen))
return 0;
if (inlen > fill) {
memcpy(state->buf + state->buflen, in, fill);
blake2s_compress_generic(state, state->buf, 1, BLAKE2S_BLOCK_SIZE);
state->buflen = 0;
in += fill;
inlen -= fill;
}
if (inlen > BLAKE2S_BLOCK_SIZE) {
const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
/* Hash one less (full) block than strictly possible */
blake2s_compress_generic(state, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
}
memcpy(state->buf + state->buflen, in, inlen);
state->buflen += inlen;
return 0;
}
static int crypto_blake2s_final(struct shash_desc *desc, u8 *out)
{
struct blake2s_state *state = shash_desc_ctx(desc);
blake2s_set_lastblock(state);
memset(state->buf + state->buflen, 0,
BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
blake2s_compress_generic(state, state->buf, 1, state->buflen);
cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
memcpy(out, state->h, state->outlen);
memzero_explicit(state, sizeof(*state));
return 0;
}
static struct shash_alg blake2s_algs[] = {{
.base.cra_name = "blake2s-128",
.base.cra_driver_name = "blake2s-128-generic",
.base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
.base.cra_ctxsize = sizeof(struct blake2s_tfm_ctx),
.base.cra_priority = 200,
.base.cra_blocksize = BLAKE2S_BLOCK_SIZE,
.base.cra_module = THIS_MODULE,
.digestsize = BLAKE2S_128_HASH_SIZE,
.setkey = crypto_blake2s_setkey,
.init = crypto_blake2s_init,
.update = crypto_blake2s_update,
.final = crypto_blake2s_final,
.descsize = sizeof(struct blake2s_state),
}, {
.base.cra_name = "blake2s-160",
.base.cra_driver_name = "blake2s-160-generic",
.base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
.base.cra_ctxsize = sizeof(struct blake2s_tfm_ctx),
.base.cra_priority = 200,
.base.cra_blocksize = BLAKE2S_BLOCK_SIZE,
.base.cra_module = THIS_MODULE,
.digestsize = BLAKE2S_160_HASH_SIZE,
.setkey = crypto_blake2s_setkey,
.init = crypto_blake2s_init,
.update = crypto_blake2s_update,
.final = crypto_blake2s_final,
.descsize = sizeof(struct blake2s_state),
}, {
.base.cra_name = "blake2s-224",
.base.cra_driver_name = "blake2s-224-generic",
.base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
.base.cra_ctxsize = sizeof(struct blake2s_tfm_ctx),
.base.cra_priority = 200,
.base.cra_blocksize = BLAKE2S_BLOCK_SIZE,
.base.cra_module = THIS_MODULE,
.digestsize = BLAKE2S_224_HASH_SIZE,
.setkey = crypto_blake2s_setkey,
.init = crypto_blake2s_init,
.update = crypto_blake2s_update,
.final = crypto_blake2s_final,
.descsize = sizeof(struct blake2s_state),
}, {
.base.cra_name = "blake2s-256",
.base.cra_driver_name = "blake2s-256-generic",
.base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
.base.cra_ctxsize = sizeof(struct blake2s_tfm_ctx),
.base.cra_priority = 200,
.base.cra_blocksize = BLAKE2S_BLOCK_SIZE,
.base.cra_module = THIS_MODULE,
.digestsize = BLAKE2S_256_HASH_SIZE,
.setkey = crypto_blake2s_setkey,
.init = crypto_blake2s_init,
.update = crypto_blake2s_update,
.final = crypto_blake2s_final,
.descsize = sizeof(struct blake2s_state),
}};
static int __init blake2s_mod_init(void)
{
return crypto_register_shashes(blake2s_algs, ARRAY_SIZE(blake2s_algs));
}
static void __exit blake2s_mod_exit(void)
{
crypto_unregister_shashes(blake2s_algs, ARRAY_SIZE(blake2s_algs));
}
subsys_initcall(blake2s_mod_init);
module_exit(blake2s_mod_exit);
MODULE_ALIAS_CRYPTO("blake2s-128");
MODULE_ALIAS_CRYPTO("blake2s-128-generic");
MODULE_ALIAS_CRYPTO("blake2s-160");
MODULE_ALIAS_CRYPTO("blake2s-160-generic");
MODULE_ALIAS_CRYPTO("blake2s-224");
MODULE_ALIAS_CRYPTO("blake2s-224-generic");
MODULE_ALIAS_CRYPTO("blake2s-256");
MODULE_ALIAS_CRYPTO("blake2s-256-generic");
MODULE_LICENSE("GPL v2");