[PATCH 4.11 052/115] crypto: skcipher - Add missing API setkey checks

Greg Kroah-Hartman
2017-06-05T16:30:58Z

From: Herbert Xu <herbert@gondor.apana.org.au>

commit 9933e113c2e87a9f46a40fde8dafbf801dca1ab9 upstream.

The API setkey checks for key sizes and alignment went AWOL during the
skcipher conversion. This patch restores them.

Fixes: 4e6c3df4d729 ("crypto: skcipher - Add low-level skcipher...")
Reported-by: Baozeng <sploving1@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
crypto/skcipher.c | 40 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 39 insertions(+), 1 deletion(-)

--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -764,6 +764,44 @@ static int crypto_init_skcipher_ops_ablk
return 0;
}

+static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
+ const u8 *key, unsigned int keylen)
+{
+ unsigned long alignmask = crypto_skcipher_alignmask(tfm);
+ struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
+ u8 *buffer, *alignbuffer;
+ unsigned long absize;
+ int ret;
+
+ 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 = cipher->setkey(tfm, alignbuffer, keylen);
+ kzfree(buffer);
+ return ret;
+}
+
+static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keylen)
+{
+ struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
+ unsigned long alignmask = crypto_skcipher_alignmask(tfm);
+
+ if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
+ crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+ return -EINVAL;
+ }
+
+ if ((unsigned long)key & alignmask)
+ return skcipher_setkey_unaligned(tfm, key, keylen);
+
+ return cipher->setkey(tfm, key, keylen);
+}
+
static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
@@ -784,7 +822,7 @@ static int crypto_skcipher_init_tfm(stru
tfm->__crt_alg->cra_type == &crypto_givcipher_type)
return crypto_init_skcipher_ops_ablkcipher(tfm);

- skcipher->setkey = alg->setkey;
+ skcipher->setkey = skcipher_setkey;
skcipher->encrypt = alg->encrypt;
skcipher->decrypt = alg->decrypt;
skcipher->ivsize = alg->ivsize;