[CRYPTO] skcipher: Add skcipher_geniv_alloc/skcipher_geniv_free

This patch creates the infrastructure to help the construction of givcipher
templates that wrap around existing blkcipher/ablkcipher algorithms by adding
an IV generator to them.

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

1 files changed, 9 insertions, 1 deletions

diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
index 8f48b4d58fca..092d9659b861 100644
--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -80,6 +80,7 @@ static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
         crt->setkey = setkey;
         crt->encrypt = alg->encrypt;
         crt->decrypt = alg->decrypt;
+        crt->base = __crypto_ablkcipher_cast(tfm);
         crt->ivsize = alg->ivsize;
 
         return 0;
@@ -122,11 +123,13 @@ static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
         if (alg->ivsize > PAGE_SIZE / 8)
                 return -EINVAL;
 
-        crt->setkey = setkey;
+        crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
+                      alg->setkey : setkey;
         crt->encrypt = alg->encrypt;
         crt->decrypt = alg->decrypt;
         crt->givencrypt = alg->givencrypt;
         crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
+        crt->base = __crypto_ablkcipher_cast(tfm);
         crt->ivsize = alg->ivsize;
 
         return 0;
@@ -155,6 +158,11 @@ const struct crypto_type crypto_givcipher_type = {
 };
 EXPORT_SYMBOL_GPL(crypto_givcipher_type);
 
+const char *crypto_default_geniv(const struct crypto_alg *alg)
+{
+        return alg->cra_flags & CRYPTO_ALG_ASYNC ? "eseqiv" : "chainiv";
+}
+
 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
                          u32 type, u32 mask)
 {