Commit dc26c17f authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: aead - prevent using AEADs without setting key 



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: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent f8d33fac

crypto/aead.c

+11 −2
Original line number Diff line number Diff line
@@ -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);



	if (err)

		return err;



	return crypto_aead_alg(tfm)->setkey(tfm, key, keylen);

	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)

crypto/algif_aead.c

+3 −8
Original line number Diff line number Diff line
@@ -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);

include/crypto/aead.h

+9 −1
Original line number Diff line number Diff line
@@ -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;

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