[CRYPTO] null: Add null blkcipher algorithm
This patch adds a null blkcipher algorithm called ecb(cipher_null) for
backwards compatibility. Previously the null algorithm when used by
IPsec copied the data byte by byte. This new algorithm optimises that
to a straight memcpy which lets us better measure inherent overheads in
our IPsec code.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/crypto_null.c b/crypto/crypto_null.c
index 29f7747..fc2d2a4 100644
--- a/crypto/crypto_null.c
+++ b/crypto/crypto_null.c
@@ -16,15 +16,17 @@
* (at your option) any later version.
*
*/
+
+#include <crypto/internal/skcipher.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
-#include <linux/crypto.h>
#include <linux/string.h>
#define NULL_KEY_SIZE 0
#define NULL_BLOCK_SIZE 1
#define NULL_DIGEST_SIZE 0
+#define NULL_IV_SIZE 0
static int null_compress(struct crypto_tfm *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen)
@@ -55,6 +57,26 @@
memcpy(dst, src, NULL_BLOCK_SIZE);
}
+static int skcipher_null_crypt(struct blkcipher_desc *desc,
+ struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct blkcipher_walk walk;
+ int err;
+
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt(desc, &walk);
+
+ while (walk.nbytes) {
+ if (walk.src.virt.addr != walk.dst.virt.addr)
+ memcpy(walk.dst.virt.addr, walk.src.virt.addr,
+ walk.nbytes);
+ err = blkcipher_walk_done(desc, &walk, 0);
+ }
+
+ return err;
+}
+
static struct crypto_alg compress_null = {
.cra_name = "compress_null",
.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
@@ -96,6 +118,25 @@
.cia_decrypt = null_crypt } }
};
+static struct crypto_alg skcipher_null = {
+ .cra_name = "ecb(cipher_null)",
+ .cra_driver_name = "ecb-cipher_null",
+ .cra_priority = 100,
+ .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
+ .cra_blocksize = NULL_BLOCK_SIZE,
+ .cra_type = &crypto_blkcipher_type,
+ .cra_ctxsize = 0,
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(skcipher_null.cra_list),
+ .cra_u = { .blkcipher = {
+ .min_keysize = NULL_KEY_SIZE,
+ .max_keysize = NULL_KEY_SIZE,
+ .ivsize = NULL_IV_SIZE,
+ .setkey = null_setkey,
+ .encrypt = skcipher_null_crypt,
+ .decrypt = skcipher_null_crypt } }
+};
+
MODULE_ALIAS("compress_null");
MODULE_ALIAS("digest_null");
MODULE_ALIAS("cipher_null");
@@ -108,27 +149,35 @@
if (ret < 0)
goto out;
+ ret = crypto_register_alg(&skcipher_null);
+ if (ret < 0)
+ goto out_unregister_cipher;
+
ret = crypto_register_alg(&digest_null);
- if (ret < 0) {
- crypto_unregister_alg(&cipher_null);
- goto out;
- }
+ if (ret < 0)
+ goto out_unregister_skcipher;
ret = crypto_register_alg(&compress_null);
- if (ret < 0) {
- crypto_unregister_alg(&digest_null);
- crypto_unregister_alg(&cipher_null);
- goto out;
- }
+ if (ret < 0)
+ goto out_unregister_digest;
out:
return ret;
+
+out_unregister_digest:
+ crypto_unregister_alg(&digest_null);
+out_unregister_skcipher:
+ crypto_unregister_alg(&skcipher_null);
+out_unregister_cipher:
+ crypto_unregister_alg(&cipher_null);
+ goto out;
}
static void __exit fini(void)
{
crypto_unregister_alg(&compress_null);
crypto_unregister_alg(&digest_null);
+ crypto_unregister_alg(&skcipher_null);
crypto_unregister_alg(&cipher_null);
}