[PATCH 1/4] crypto: skcipher - Add crypto_skcipher_has_setkey

[Kamal Mostafa]

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

BugLink: http://bugs.launchpad.net/bugs/1556562

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 at gondor.apana.org.au>
[bwh: Backported to 3.2: add to ablkcipher API instead]
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 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 e5b5721..71b4b2e 100644
--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -377,6 +377,7 @@ 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 81ef938..ab5f912 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -552,6 +552,7 @@ struct ablkcipher_tfm {
 
 	unsigned int ivsize;
 	unsigned int reqsize;
+	bool has_setkey;
 };
 
 struct blkcipher_tfm {
@@ -922,6 +923,13 @@ 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;
+}
+
 /**
  * crypto_ablkcipher_reqtfm() - obtain cipher handle from request
  * @req: ablkcipher_request out of which the cipher handle is to be obtained
-- 
2.7.0