diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2015-05-21 15:11:09 +0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2015-05-22 11:25:55 +0800 |
| commit | 330234638e16b7b95e8e5e6be719a61a93f074b8 (patch) | |
| tree | 46ca4313bc5bfdec551d1cea785674621cbbe41b | |
| parent | 63293c61133447249d7e5b49d333f68825d30e43 (diff) | |
crypto: null - Add default null skcipher
This patch adds a default null skcipher for users such as gcm
to perform copies on SG lists.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| -rw-r--r-- | crypto/crypto_null.c | 39 | ||||
| -rw-r--r-- | include/crypto/null.h | 3 |
2 files changed, 42 insertions, 0 deletions
diff --git a/crypto/crypto_null.c b/crypto/crypto_null.c index a20319132e33..941c9a434d50 100644 --- a/crypto/crypto_null.c +++ b/crypto/crypto_null.c @@ -25,6 +25,10 @@ #include <linux/mm.h> #include <linux/string.h> +static DEFINE_MUTEX(crypto_default_null_skcipher_lock); +static struct crypto_blkcipher *crypto_default_null_skcipher; +static int crypto_default_null_skcipher_refcnt; + static int null_compress(struct crypto_tfm *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int *dlen) { @@ -149,6 +153,41 @@ MODULE_ALIAS_CRYPTO("compress_null"); MODULE_ALIAS_CRYPTO("digest_null"); MODULE_ALIAS_CRYPTO("cipher_null"); +struct crypto_blkcipher *crypto_get_default_null_skcipher(void) +{ + struct crypto_blkcipher *tfm; + + mutex_lock(&crypto_default_null_skcipher_lock); + tfm = crypto_default_null_skcipher; + + if (!tfm) { + tfm = crypto_alloc_blkcipher("ecb(cipher_null)", 0, 0); + if (IS_ERR(tfm)) + goto unlock; + + crypto_default_null_skcipher = tfm; + } + + crypto_default_null_skcipher_refcnt++; + +unlock: + mutex_unlock(&crypto_default_null_skcipher_lock); + + return tfm; +} +EXPORT_SYMBOL_GPL(crypto_get_default_null_skcipher); + +void crypto_put_default_null_skcipher(void) +{ + mutex_lock(&crypto_default_null_skcipher_lock); + if (!--crypto_default_null_skcipher_refcnt) { + crypto_free_blkcipher(crypto_default_null_skcipher); + crypto_default_null_skcipher = NULL; + } + mutex_unlock(&crypto_default_null_skcipher_lock); +} +EXPORT_SYMBOL_GPL(crypto_put_default_null_skcipher); + static int __init crypto_null_mod_init(void) { int ret = 0; diff --git a/include/crypto/null.h b/include/crypto/null.h index b7c864cc70df..06dc30d9f56e 100644 --- a/include/crypto/null.h +++ b/include/crypto/null.h @@ -8,4 +8,7 @@ #define NULL_DIGEST_SIZE 0 #define NULL_IV_SIZE 0 +struct crypto_blkcipher *crypto_get_default_null_skcipher(void); +void crypto_put_default_null_skcipher(void); + #endif |