crypto: skcipher - Add crypto_skcipher_has_setkey

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@gondor.apana.org.au>
[bwh: Backported to 3.2: add to ablkcipher API instead]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
index 6eb6eb1..6600a2a 100644 (file)
--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -379,6 +379,7 @@ 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 ca01ea8..6f501de 100644 (file)
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -346,6 +346,7 @@ struct ablkcipher_tfm {
 
        unsigned int ivsize;
        unsigned int reqsize;
+       bool has_setkey;
 };
 
 struct aead_tfm {
@@ -656,6 +657,13 @@ 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)
 {