As it stands salsa20 cannot do chaining. That is, it has to handle
each request as a whole. This patch adds support for chaining when
the CRYPTO_TFM_REQ_MORE flag is set.
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
---
crypto/salsa20_generic.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/crypto/salsa20_generic.c b/crypto/salsa20_generic.c
index 3418869dabefd..dd4b4cc8e76b9 100644
--- a/crypto/salsa20_generic.c
+++ b/crypto/salsa20_generic.c
@@ -21,7 +21,10 @@
#include <asm/unaligned.h>
#include <crypto/internal/skcipher.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/string.h>
#define SALSA20_IV_SIZE 8
#define SALSA20_MIN_KEY_SIZE 16
@@ -32,6 +35,11 @@ struct salsa20_ctx {
u32 initial_state[16];
};
+struct salsa20_reqctx {
+ u32 state[16];
+ bool init;
+};
+
static void salsa20_block(u32 *state, __le32 *stream)
{
u32 x[16];
@@ -154,13 +162,16 @@ static int salsa20_crypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
const struct salsa20_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct salsa20_reqctx *rctx = skcipher_request_ctx(req);
struct skcipher_walk walk;
- u32 state[16];
int err;
err = skcipher_walk_virt(&walk, req, false);
- salsa20_init(state, ctx, req->iv);
+ if (!rctx->init)
+ salsa20_init(rctx->state, ctx, req->iv);
+
+ rctx->init = req->base.flags & CRYPTO_TFM_REQ_MORE;
while (walk.nbytes > 0) {
unsigned int nbytes = walk.nbytes;
@@ -168,8 +179,8 @@ static int salsa20_crypt(struct skcipher_request *req)
if (nbytes < walk.total)
nbytes = round_down(nbytes, walk.stride);
- salsa20_docrypt(state, walk.dst.virt.addr, walk.src.virt.addr,
- nbytes);
+ salsa20_docrypt(rctx->state, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes);
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
@@ -188,6 +199,7 @@ static struct skcipher_alg alg = {
.max_keysize = SALSA20_MAX_KEY_SIZE,
.ivsize = SALSA20_IV_SIZE,
.chunksize = SALSA20_BLOCK_SIZE,
+ .reqsize = sizeof(struct salsa20_reqctx),
.setkey = salsa20_setkey,
.encrypt = salsa20_crypt,
.decrypt = salsa20_crypt,
