From 5d78d57ede8f9e7f656c610ed25be7be337e0529 Mon Sep 17 00:00:00 2001 From: Tero Kristo Date: Wed, 24 May 2017 10:35:32 +0300 Subject: crypto: omap-sham - buffer handling fixes for hashing later Currently, the hash later code only handles the cases when we have either new data coming in with the request or old data in the buffer, but not the combination when we have both. Fix this by changing the ordering of the code a bit and handling both cases properly simultaneously if needed. Also, fix an issue with omap_sham_update that surfaces with this fix, so that the code checks the bufcnt instead of total data amount against buffer length to avoid any buffer overflows. Signed-off-by: Tero Kristo Signed-off-by: Herbert Xu --- drivers/crypto/omap-sham.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) (limited to 'drivers/crypto') diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c index 1864a57caaa4..ca9e48a19b15 100644 --- a/drivers/crypto/omap-sham.c +++ b/drivers/crypto/omap-sham.c @@ -874,14 +874,21 @@ static int omap_sham_prepare_request(struct ahash_request *req, bool update) } if (hash_later) { - if (req->nbytes) { - scatterwalk_map_and_copy(rctx->buffer, req->src, - req->nbytes - hash_later, - hash_later, 0); - } else { + int offset = 0; + + if (hash_later > req->nbytes) { memcpy(rctx->buffer, rctx->buffer + xmit_len, - hash_later); + hash_later - req->nbytes); + offset = hash_later - req->nbytes; } + + if (req->nbytes) { + scatterwalk_map_and_copy(rctx->buffer + offset, + req->src, + offset + req->nbytes - + hash_later, hash_later, 0); + } + rctx->bufcnt = hash_later; } else { rctx->bufcnt = 0; @@ -1190,11 +1197,10 @@ static int omap_sham_update(struct ahash_request *req) if (!req->nbytes) return 0; - if (ctx->total + req->nbytes < ctx->buflen) { + if (ctx->bufcnt + req->nbytes <= ctx->buflen) { scatterwalk_map_and_copy(ctx->buffer + ctx->bufcnt, req->src, 0, req->nbytes, 0); ctx->bufcnt += req->nbytes; - ctx->total += req->nbytes; return 0; } -- cgit v1.2.3