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authorTero Kristo <t-kristo@ti.com>2016-08-04 13:28:40 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2016-09-13 15:20:56 +0300
commitcb8d5c8346640f3622bc832fede4b514096f762e (patch)
tree7f62a6dc9daf45eb4c6b1117176765b067c44c5c /drivers/crypto/omap-sham.c
parent5a793bcadbe97df7823598b429c0af052e50df1c (diff)
downloadlinux-cb8d5c8346640f3622bc832fede4b514096f762e.tar.xz
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 <t-kristo@ti.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto/omap-sham.c')
-rw-r--r--drivers/crypto/omap-sham.c13
1 files changed, 12 insertions, 1 deletions
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)