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crypto: aead - prevent using AEADs without setting key

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Similar to what was done for the hash API, update the AEAD API to track
whether each transform has been keyed, and reject encryption/decryption
if a key is needed but one hasn't been set.

This isn't quite as important as the equivalent fix for the hash API
because AEADs always require a key, so are unlikely to be used without
one.  Still, tracking the key will prevent accidental unkeyed use.
algif_aead also had to track the key anyway, so the new flag replaces
that and slightly simplifies the algif_aead implementation.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Eric Biggers 2018-01-03 11:16:30 -08:00 committed by Herbert Xu
parent f8d33fac84
commit dc26c17f74
3 changed files with 23 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
crypto/aead.c
View File

@ -54,11 +54,18 @@ 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)
return setkey_unaligned(tfm, key, keylen);
err = setkey_unaligned(tfm, key, keylen);
else
err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
return crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
if (err)
return err;
crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_aead_setkey);
@ -93,6 +100,8 @@ 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)

11
crypto/algif_aead.c
View File

@ -42,7 +42,6 @@
struct aead_tfm {
struct crypto_aead *aead;
bool has_key;
struct crypto_skcipher *null_tfm;
};
@ -398,7 +397,7 @@ static int aead_check_key(struct socket *sock)
err = -ENOKEY;
lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
if (!tfm->has_key)
if (crypto_aead_get_flags(tfm->aead) & CRYPTO_TFM_NEED_KEY)
goto unlock;
if (!pask->refcnt++)
@ -523,12 +522,8 @@ static int aead_setauthsize(void *private, unsigned int authsize)
static int aead_setkey(void *private, const u8 *key, unsigned int keylen)
{
struct aead_tfm *tfm = private;
int err;
err = crypto_aead_setkey(tfm->aead, key, keylen);
tfm->has_key = !err;
return err;
return crypto_aead_setkey(tfm->aead, key, keylen);
}
static void aead_sock_destruct(struct sock *sk)
@ -589,7 +584,7 @@ static int aead_accept_parent(void *private, struct sock *sk)
{
struct aead_tfm *tfm = private;
if (!tfm->has_key)
if (crypto_aead_get_flags(tfm->aead) & CRYPTO_TFM_NEED_KEY)
return -ENOKEY;
return aead_accept_parent_nokey(private, sk);

10
include/crypto/aead.h
View File

@ -327,7 +327,12 @@ static inline struct crypto_aead *crypto_aead_reqtfm(struct aead_request *req)
*/
static inline int crypto_aead_encrypt(struct aead_request *req)
{
return crypto_aead_alg(crypto_aead_reqtfm(req))->encrypt(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);
}
/**
@ -356,6 +361,9 @@ static inline 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;