crypto: skcipher - prevent using skciphers without setting key
Similar to what was done for the hash API, update the skcipher 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 as important as the equivalent fix for the hash API because
symmetric ciphers almost always require a key (the "null cipher" is the
only exception), so are unlikely to be used without one. Still,
tracking the key will prevent accidental unkeyed use. algif_skcipher
also had to track the key anyway, so the new flag replaces that and
simplifies the algif_skcipher implementation.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/crypto/skcipher.h b/include/crypto/skcipher.h
index 562001c..2f327f0 100644
--- a/include/crypto/skcipher.h
+++ b/include/crypto/skcipher.h
@@ -401,11 +401,6 @@ static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
return tfm->setkey(tfm, key, keylen);
}
-static inline bool crypto_skcipher_has_setkey(struct crypto_skcipher *tfm)
-{
- return tfm->keysize;
-}
-
static inline unsigned int crypto_skcipher_default_keysize(
struct crypto_skcipher *tfm)
{
@@ -442,6 +437,9 @@ static inline int crypto_skcipher_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+ return -ENOKEY;
+
return tfm->encrypt(req);
}
@@ -460,6 +458,9 @@ static inline int crypto_skcipher_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+ return -ENOKEY;
+
return tfm->decrypt(req);
}
