[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, 25 insertions, 0 deletions

diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
index 9348ddd..d45fa16 100644
--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -19,16 +19,41 @@
 #include <linux/module.h>
 #include <linux/seq_file.h>
 
+static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key, unsigned int keylen)
+{
+	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
+	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
+	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 = cipher->setkey(tfm, alignbuffer, keylen);
+	memset(alignbuffer, 0, absize);
+	kfree(buffer);
+	return ret;
+}
+
 static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
 		  unsigned int keylen)
 {
 	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
+	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
 
 	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 		return -EINVAL;
 	}
 
+	if ((unsigned long)key & alignmask)
+		return setkey_unaligned(tfm, key, keylen);
+
 	return cipher->setkey(tfm, key, keylen);
 }