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 <[email protected]> --- 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,
