From dc26c17f743aa8e4720a5fda577dde855f2e36f8 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 3 Jan 2018 11:16:30 -0800 Subject: [PATCH] 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: Eric Biggers Signed-off-by: Herbert Xu --- crypto/aead.c | 13 +++++++++++-- crypto/algif_aead.c | 11 +++-------- include/crypto/aead.h | 10 +++++++++- 3 files changed, 23 insertions(+), 11 deletions(-) diff --git a/crypto/aead.c b/crypto/aead.c index fe00cbd7243d..60b3bbe973e7 100644 --- a/crypto/aead.c +++ b/crypto/aead.c @@ -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) diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c index d963c8cf8a55..4b07edd5a9ff 100644 --- a/crypto/algif_aead.c +++ b/crypto/algif_aead.c @@ -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); diff --git a/include/crypto/aead.h b/include/crypto/aead.h index 03b97629442c..1e26f790b03f 100644 --- a/include/crypto/aead.h +++ b/include/crypto/aead.h @@ -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;