crypto: null - Add new default null skcipher

Current the default null skcipher is actually a crypto_blkcipher.
This patch creates a synchronous crypto_skcipher version of the
null cipher which unfortunately has to settle for the name skcipher2.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 38 insertions, 0 deletions

diff --git a/crypto/crypto_null.c b/crypto/crypto_null.c
index 941c9a434d50..c3f683910d07 100644
--- a/crypto/crypto_null.c
+++ b/crypto/crypto_null.c
@@ -28,6 +28,8 @@
 static DEFINE_MUTEX(crypto_default_null_skcipher_lock);
 static struct crypto_blkcipher *crypto_default_null_skcipher;
 static int crypto_default_null_skcipher_refcnt;
+static struct crypto_skcipher *crypto_default_null_skcipher2;
+static int crypto_default_null_skcipher2_refcnt;
 
 static int null_compress(struct crypto_tfm *tfm, const u8 *src,
                          unsigned int slen, u8 *dst, unsigned int *dlen)
@@ -188,6 +190,42 @@ void crypto_put_default_null_skcipher(void)
 }
 EXPORT_SYMBOL_GPL(crypto_put_default_null_skcipher);
 
+struct crypto_skcipher *crypto_get_default_null_skcipher2(void)
+{
+        struct crypto_skcipher *tfm;
+
+        mutex_lock(&crypto_default_null_skcipher_lock);
+        tfm = crypto_default_null_skcipher2;
+
+        if (!tfm) {
+                tfm = crypto_alloc_skcipher("ecb(cipher_null)",
+                                            0, CRYPTO_ALG_ASYNC);
+                if (IS_ERR(tfm))
+                        goto unlock;
+
+                crypto_default_null_skcipher2 = tfm;
+        }
+
+        crypto_default_null_skcipher2_refcnt++;
+
+unlock:
+        mutex_unlock(&crypto_default_null_skcipher_lock);
+
+        return tfm;
+}
+EXPORT_SYMBOL_GPL(crypto_get_default_null_skcipher2);
+
+void crypto_put_default_null_skcipher2(void)
+{
+        mutex_lock(&crypto_default_null_skcipher_lock);
+        if (!--crypto_default_null_skcipher2_refcnt) {
+                crypto_free_skcipher(crypto_default_null_skcipher2);
+                crypto_default_null_skcipher2 = NULL;
+        }
+        mutex_unlock(&crypto_default_null_skcipher_lock);
+}
+EXPORT_SYMBOL_GPL(crypto_put_default_null_skcipher2);
+
 static int __init crypto_null_mod_init(void)
 {
         int ret = 0;