From 214a9bd0f8dec468de6a32f445c540f786773ee8 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Antoine=20T=C3=A9nart?= Date: Thu, 1 Jun 2017 21:38:58 +0200 Subject: [PATCH] crypto: sun4i-ss - simplify the pad length calculation When sending the last block of data to the engine, it should be padded so that the total length of the request can be given to the engine as the last 2 words of the last 64 bytes block. Simplify the calculation of this pad offset. Signed-off-by: Antoine Tenart Tested-by: Corentin Labbe Acked-by: Corentin Labbe Signed-off-by: Herbert Xu --- drivers/crypto/sunxi-ss/sun4i-ss-hash.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-hash.c b/drivers/crypto/sunxi-ss/sun4i-ss-hash.c index 518bc7a..59d9b44 100644 --- a/drivers/crypto/sunxi-ss/sun4i-ss-hash.c +++ b/drivers/crypto/sunxi-ss/sun4i-ss-hash.c @@ -177,7 +177,7 @@ static int sun4i_hash(struct ahash_request *areq) * * in_i: advancement in the current SG */ - unsigned int i = 0, end, index, padlen, nwait, nbw = 0, j = 0, todo; + unsigned int i = 0, end, fill, min_fill, nwait, nbw = 0, j = 0, todo; unsigned int in_i = 0; u32 spaces, rx_cnt = SS_RX_DEFAULT, bf[32] = {0}, wb = 0, v, ivmode = 0; struct sun4i_req_ctx *op = ahash_request_ctx(areq); @@ -186,7 +186,7 @@ static int sun4i_hash(struct ahash_request *areq) struct sun4i_ss_ctx *ss = tfmctx->ss; struct scatterlist *in_sg = areq->src; struct sg_mapping_iter mi; - int in_r, err = 0, zeros; + int in_r, err = 0; size_t copied = 0; dev_dbg(ss->dev, "%s %s bc=%llu len=%u mode=%x wl=%u h0=%0x", @@ -387,6 +387,8 @@ hash_final: nbw = op->len - 4 * nwait; wb = *(u32 *)(op->buf + nwait * 4); wb &= (0xFFFFFFFF >> (4 - nbw) * 8); + + op->byte_count += nbw; } /* write the remaining bytes of the nbw buffer */ @@ -402,22 +404,15 @@ hash_final: * I take the operations from other MD5/SHA1 implementations */ - /* we have already send 4 more byte of which nbw data */ - if (op->mode == SS_OP_MD5) { - index = (op->byte_count + 4) & 0x3f; - op->byte_count += nbw; - if (index > 56) - zeros = (120 - index) / 4; - else - zeros = (56 - index) / 4; - } else { - op->byte_count += nbw; - index = op->byte_count & 0x3f; - padlen = (index < 56) ? (56 - index) : ((64 + 56) - index); - zeros = (padlen - 1) / 4; - } + /* last block size */ + fill = 64 - (op->byte_count % 64); + min_fill = 2 * sizeof(u32) + (nbw ? 0 : sizeof(u32)); + + /* if we can't fill all data, jump to the next 64 block */ + if (fill < min_fill) + fill += 64; - j += zeros; + j += (fill - min_fill) / sizeof(u32); /* write the length of data */ if (op->mode == SS_OP_SHA1) { -- 2.7.4