[CRYPTO] api: Handle unaligned keys in setkey

setkey() in {cipher,blkcipher,ablkcipher,hash}.c does not respect the
requested alignment by the algorithm. This patch fixes it. The extra
memory is allocated by kmalloc() with GFP_ATOMIC flag.

Signed-off-by: Sebastian Siewior <linux-crypto@ml.breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 37 insertions, 1 deletions

diff --git a/crypto/hash.c b/crypto/hash.c
index 4ccd22deef3..4d75ca7b57b 100644
--- a/crypto/hash.c
+++ b/crypto/hash.c
@@ -22,6 +22,42 @@ static unsigned int crypto_hash_ctxsize(struct crypto_alg *alg, u32 type,
 	return alg->cra_ctxsize;
 }
 
+static int hash_setkey_unaligned(struct crypto_hash *crt, const u8 *key,
+		                 unsigned int keylen)
+{
+	struct crypto_tfm *tfm = crypto_hash_tfm(crt);
+	struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
+	unsigned long alignmask = crypto_hash_alignmask(crt);
+	int ret;
+	u8 *buffer, *alignbuffer;
+	unsigned long absize;
+
+	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 = alg->setkey(crt, alignbuffer, keylen);
+	memset(alignbuffer, 0, absize);
+	kfree(buffer);
+	return ret;
+}
+
+static int hash_setkey(struct crypto_hash *crt, const u8 *key,
+		unsigned int keylen)
+{
+	struct crypto_tfm *tfm = crypto_hash_tfm(crt);
+	struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
+	unsigned long alignmask = crypto_hash_alignmask(crt);
+
+	if ((unsigned long)key & alignmask)
+		return hash_setkey_unaligned(crt, key, keylen);
+
+	return alg->setkey(crt, key, keylen);
+}
+
 static int crypto_init_hash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 {
 	struct hash_tfm *crt = &tfm->crt_hash;
@@ -34,7 +70,7 @@ static int crypto_init_hash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 	crt->update = alg->update;
 	crt->final = alg->final;
 	crt->digest = alg->digest;
-	crt->setkey = alg->setkey;
+	crt->setkey = hash_setkey;
 	crt->digestsize = alg->digestsize;
 
 	return 0;