linux/crypto/aead.c
Hailey Mothershead 23e4099bdc crypto: aead,cipher - zeroize key buffer after use
I.G 9.7.B for FIPS 140-3 specifies that variables temporarily holding
cryptographic information should be zeroized once they are no longer
needed. Accomplish this by using kfree_sensitive for buffers that
previously held the private key.

Signed-off-by: Hailey Mothershead <hailmo@amazon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-04-26 17:26:09 +08:00

295 lines
7.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* AEAD: Authenticated Encryption with Associated Data
*
* This file provides API support for AEAD algorithms.
*
* Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <crypto/internal/aead.h>
#include <linux/cryptouser.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/string.h>
#include <net/netlink.h>
#include "internal.h"
static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
unsigned int keylen)
{
unsigned long alignmask = crypto_aead_alignmask(tfm);
int ret;
u8 *buffer, *alignbuffer;
unsigned long absize;
absize = keylen + alignmask;
buffer = kmalloc(absize, GFP_ATOMIC);
if (!buffer)
return -ENOMEM;
alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
kfree_sensitive(buffer);
return ret;
}
int crypto_aead_setkey(struct crypto_aead *tfm,
const u8 *key, unsigned int keylen)
{
unsigned long alignmask = crypto_aead_alignmask(tfm);
int err;
if ((unsigned long)key & alignmask)
err = setkey_unaligned(tfm, key, keylen);
else
err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
if (unlikely(err)) {
crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
return err;
}
crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_aead_setkey);
int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
{
int err;
if ((!authsize && crypto_aead_maxauthsize(tfm)) ||
authsize > crypto_aead_maxauthsize(tfm))
return -EINVAL;
if (crypto_aead_alg(tfm)->setauthsize) {
err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
if (err)
return err;
}
tfm->authsize = authsize;
return 0;
}
EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
int crypto_aead_encrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
return -ENOKEY;
return crypto_aead_alg(aead)->encrypt(req);
}
EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
int crypto_aead_decrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
return -ENOKEY;
if (req->cryptlen < crypto_aead_authsize(aead))
return -EINVAL;
return crypto_aead_alg(aead)->decrypt(req);
}
EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_aead *aead = __crypto_aead_cast(tfm);
struct aead_alg *alg = crypto_aead_alg(aead);
alg->exit(aead);
}
static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_aead *aead = __crypto_aead_cast(tfm);
struct aead_alg *alg = crypto_aead_alg(aead);
crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
aead->authsize = alg->maxauthsize;
if (alg->exit)
aead->base.exit = crypto_aead_exit_tfm;
if (alg->init)
return alg->init(aead);
return 0;
}
static int __maybe_unused crypto_aead_report(
struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_aead raead;
struct aead_alg *aead = container_of(alg, struct aead_alg, base);
memset(&raead, 0, sizeof(raead));
strscpy(raead.type, "aead", sizeof(raead.type));
strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
raead.blocksize = alg->cra_blocksize;
raead.maxauthsize = aead->maxauthsize;
raead.ivsize = aead->ivsize;
return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
}
static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
__maybe_unused;
static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
{
struct aead_alg *aead = container_of(alg, struct aead_alg, base);
seq_printf(m, "type : aead\n");
seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
"yes" : "no");
seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
seq_printf(m, "ivsize : %u\n", aead->ivsize);
seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
seq_printf(m, "geniv : <none>\n");
}
static void crypto_aead_free_instance(struct crypto_instance *inst)
{
struct aead_instance *aead = aead_instance(inst);
aead->free(aead);
}
static const struct crypto_type crypto_aead_type = {
.extsize = crypto_alg_extsize,
.init_tfm = crypto_aead_init_tfm,
.free = crypto_aead_free_instance,
#ifdef CONFIG_PROC_FS
.show = crypto_aead_show,
#endif
#if IS_ENABLED(CONFIG_CRYPTO_USER)
.report = crypto_aead_report,
#endif
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_MASK,
.type = CRYPTO_ALG_TYPE_AEAD,
.tfmsize = offsetof(struct crypto_aead, base),
};
int crypto_grab_aead(struct crypto_aead_spawn *spawn,
struct crypto_instance *inst,
const char *name, u32 type, u32 mask)
{
spawn->base.frontend = &crypto_aead_type;
return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_grab_aead);
struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
{
return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_aead);
int crypto_has_aead(const char *alg_name, u32 type, u32 mask)
{
return crypto_type_has_alg(alg_name, &crypto_aead_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_has_aead);
static int aead_prepare_alg(struct aead_alg *alg)
{
struct crypto_alg *base = &alg->base;
if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
PAGE_SIZE / 8)
return -EINVAL;
if (!alg->chunksize)
alg->chunksize = base->cra_blocksize;
base->cra_type = &crypto_aead_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
return 0;
}
int crypto_register_aead(struct aead_alg *alg)
{
struct crypto_alg *base = &alg->base;
int err;
err = aead_prepare_alg(alg);
if (err)
return err;
return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_aead);
void crypto_unregister_aead(struct aead_alg *alg)
{
crypto_unregister_alg(&alg->base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_aead);
int crypto_register_aeads(struct aead_alg *algs, int count)
{
int i, ret;
for (i = 0; i < count; i++) {
ret = crypto_register_aead(&algs[i]);
if (ret)
goto err;
}
return 0;
err:
for (--i; i >= 0; --i)
crypto_unregister_aead(&algs[i]);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_aeads);
void crypto_unregister_aeads(struct aead_alg *algs, int count)
{
int i;
for (i = count - 1; i >= 0; --i)
crypto_unregister_aead(&algs[i]);
}
EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
int aead_register_instance(struct crypto_template *tmpl,
struct aead_instance *inst)
{
int err;
if (WARN_ON(!inst->free))
return -EINVAL;
err = aead_prepare_alg(&inst->alg);
if (err)
return err;
return crypto_register_instance(tmpl, aead_crypto_instance(inst));
}
EXPORT_SYMBOL_GPL(aead_register_instance);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");