[PATCH 3.16.y-ckt 047/129] crypto: skcipher - Add crypto_skcipher_has_setkey

[Luis Henriques]

3.16.7-ckt25 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>

commit a1383cd86a062fc798899ab20f0ec2116cce39cb upstream.

This patch adds a way for skcipher users to determine whether a key
is required by a transform.

Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: add to ablkcipher API instead]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 crypto/ablkcipher.c    | 1 +
 include/linux/crypto.h | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
index f02fdbefb2c6..5da16526c890 100644
--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -375,6 +375,7 @@ static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
 	}
 	crt->base = __crypto_ablkcipher_cast(tfm);
 	crt->ivsize = alg->ivsize;
+	crt->has_setkey = alg->max_keysize;
 
 	return 0;
 }
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 2b00d92a6e6f..61dd0b15d21c 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -354,6 +354,7 @@ struct ablkcipher_tfm {
 
 	unsigned int ivsize;
 	unsigned int reqsize;
+	bool has_setkey;
 };
 
 struct aead_tfm {
@@ -664,6 +665,13 @@ static inline int crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm,
 	return crt->setkey(crt->base, key, keylen);
 }
 
+static inline bool crypto_ablkcipher_has_setkey(struct crypto_ablkcipher *tfm)
+{
+	struct ablkcipher_tfm *crt = crypto_ablkcipher_crt(tfm);
+
+	return crt->has_setkey;
+}
+
 static inline struct crypto_ablkcipher *crypto_ablkcipher_reqtfm(
 	struct ablkcipher_request *req)
 {