[CRYPTO] api: Add async block cipher interface

This patch adds the frontend interface for asynchronous block ciphers.
In addition to the usual block cipher parameters, there is a callback
function pointer and a data pointer.  The callback will be invoked only
if the encrypt/decrypt handlers return -EINPROGRESS.  In other words,
if the return value of zero the completion handler (or the equivalent
code) needs to be invoked by the caller.

The request structure is allocated and freed by the caller.  Its size
is determined by calling crypto_ablkcipher_reqsize().  The helpers
ablkcipher_request_alloc/ablkcipher_request_free can be used to manage
the memory for a request.

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

1 files changed, 65 insertions, 5 deletions

diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index bf459179efe3..8edf40c835a7 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -349,13 +349,48 @@ static int setkey(struct crypto_tfm *tfm, const u8 *key,
         return cipher->setkey(tfm, key, keylen);
 }
 
+static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+                        unsigned int keylen)
+{
+        return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
+}
+
+static int async_encrypt(struct ablkcipher_request *req)
+{
+        struct crypto_tfm *tfm = req->base.tfm;
+        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+        struct blkcipher_desc desc = {
+                .tfm = __crypto_blkcipher_cast(tfm),
+                .info = req->info,
+                .flags = req->base.flags,
+        };
+
+
+        return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
+}
+
+static int async_decrypt(struct ablkcipher_request *req)
+{
+        struct crypto_tfm *tfm = req->base.tfm;
+        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+        struct blkcipher_desc desc = {
+                .tfm = __crypto_blkcipher_cast(tfm),
+                .info = req->info,
+                .flags = req->base.flags,
+        };
+
+        return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
+}
+
 static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
                                              u32 mask)
 {
         struct blkcipher_alg *cipher = &alg->cra_blkcipher;
         unsigned int len = alg->cra_ctxsize;
 
-        if (cipher->ivsize) {
+        type ^= CRYPTO_ALG_ASYNC;
+        mask &= CRYPTO_ALG_ASYNC;
+        if ((type & mask) && cipher->ivsize) {
                 len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
                 len += cipher->ivsize;
         }
@@ -363,16 +398,26 @@ static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
         return len;
 }
 
-static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
+static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
+{
+        struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
+        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+
+        crt->setkey = async_setkey;
+        crt->encrypt = async_encrypt;
+        crt->decrypt = async_decrypt;
+        crt->ivsize = alg->ivsize;
+
+        return 0;
+}
+
+static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
 {
         struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
         unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
         unsigned long addr;
 
-        if (alg->ivsize > PAGE_SIZE / 8)
-                return -EINVAL;
-
         crt->setkey = setkey;
         crt->encrypt = alg->encrypt;
         crt->decrypt = alg->decrypt;
@@ -385,6 +430,21 @@ static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
         return 0;
 }
 
+static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
+{
+        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+
+        if (alg->ivsize > PAGE_SIZE / 8)
+                return -EINVAL;
+
+        type ^= CRYPTO_ALG_ASYNC;
+        mask &= CRYPTO_ALG_ASYNC;
+        if (type & mask)
+                return crypto_init_blkcipher_ops_sync(tfm);
+        else
+                return crypto_init_blkcipher_ops_async(tfm);
+}
+
 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
         __attribute__ ((unused));
 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)