From cb8d5c8346640f3622bc832fede4b514096f762e Mon Sep 17 00:00:00 2001 From: Tero Kristo Date: Thu, 4 Aug 2016 13:28:40 +0300 Subject: [PATCH] crypto: omap-sham - fix SW fallback HMAC handling for omap2/omap3 If software fallback is used on older hardware accelerator setup (OMAP2/ OMAP3), the first block of data must be purged from the buffer. The first block contains the pre-generated ipad value required by the HW, but the software fallback algorithm generates its own, causing wrong results. Signed-off-by: Tero Kristo Signed-off-by: Herbert Xu --- drivers/crypto/omap-sham.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c index f788319f7ba7..cf9f617cfcd7 100644 --- a/drivers/crypto/omap-sham.c +++ b/drivers/crypto/omap-sham.c @@ -1143,9 +1143,20 @@ static int omap_sham_final_shash(struct ahash_request *req) { struct omap_sham_ctx *tctx = crypto_tfm_ctx(req->base.tfm); struct omap_sham_reqctx *ctx = ahash_request_ctx(req); + int offset = 0; + + /* + * If we are running HMAC on limited hardware support, skip + * the ipad in the beginning of the buffer if we are going for + * software fallback algorithm. + */ + if (test_bit(FLAGS_HMAC, &ctx->flags) && + !test_bit(FLAGS_AUTO_XOR, &ctx->dd->flags)) + offset = get_block_size(ctx); return omap_sham_shash_digest(tctx->fallback, req->base.flags, - ctx->buffer, ctx->bufcnt, req->result); + ctx->buffer + offset, + ctx->bufcnt - offset, req->result); } static int omap_sham_final(struct ahash_request *req) -- 2.20.1