From: Andrey Smirnov <andrew.smirnov@gmail.com>
To: linux-crypto@vger.kernel.org
Cc: "Andrey Smirnov" <andrew.smirnov@gmail.com>,
"Chris Healy" <cphealy@gmail.com>,
"Lucas Stach" <l.stach@pengutronix.de>,
"Horia Geantă" <horia.geanta@nxp.com>,
"Herbert Xu" <herbert@gondor.apana.org.au>,
"Iuliana Prodan" <iuliana.prodan@nxp.com>,
linux-kernel@vger.kernel.org, linux-imx@nxp.com
Subject: [PATCH v8 8/8] crypto: caam - limit single JD RNG output to maximum of 16 bytes
Date: Mon, 16 Mar 2020 08:00:47 -0700 [thread overview]
Message-ID: <20200316150047.30828-9-andrew.smirnov@gmail.com> (raw)
In-Reply-To: <20200316150047.30828-1-andrew.smirnov@gmail.com>
In order to follow recommendation in SP800-90C (section "9.4 The
Oversampling-NRBG Construction") limit the output of "generate" JD
submitted to CAAM. See
https://lore.kernel.org/linux-crypto/VI1PR0402MB3485EF10976A4A69F90E5B0F98580@VI1PR0402MB3485.eurprd04.prod.outlook.com/
for more details.
This change should make CAAM's hwrng driver good enough to have 1024
quality rating.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Horia Geantă <horia.geanta@nxp.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Iuliana Prodan <iuliana.prodan@nxp.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-imx@nxp.com
---
drivers/crypto/caam/caamrng.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
index cffa6604f726..77d048dfe5d0 100644
--- a/drivers/crypto/caam/caamrng.c
+++ b/drivers/crypto/caam/caamrng.c
@@ -22,9 +22,7 @@
#include "jr.h"
#include "error.h"
-#define CAAM_RNG_MAX_FIFO_STORE_SIZE U16_MAX
-
-#define CAAM_RNG_FIFO_LEN SZ_32K /* Must be a multiple of 2 */
+#define CAAM_RNG_MAX_FIFO_STORE_SIZE 16
/*
* Length of used descriptors, see caam_init_desc()
@@ -65,14 +63,15 @@ static void caam_rng_done(struct device *jrdev, u32 *desc, u32 err,
complete(jctx->done);
}
-static u32 *caam_init_desc(u32 *desc, dma_addr_t dst_dma, int len)
+static u32 *caam_init_desc(u32 *desc, dma_addr_t dst_dma)
{
init_job_desc(desc, 0); /* + 1 cmd_sz */
/* Generate random bytes: + 1 cmd_sz */
append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG |
OP_ALG_PR_ON);
/* Store bytes: + 1 cmd_sz + caam_ptr_sz */
- append_fifo_store(desc, dst_dma, len, FIFOST_TYPE_RNGSTORE);
+ append_fifo_store(desc, dst_dma,
+ CAAM_RNG_MAX_FIFO_STORE_SIZE, FIFOST_TYPE_RNGSTORE);
print_hex_dump_debug("rng job desc@: ", DUMP_PREFIX_ADDRESS,
16, 4, desc, desc_bytes(desc), 1);
@@ -92,7 +91,7 @@ static int caam_rng_read_one(struct device *jrdev,
.err = &ret,
};
- len = min_t(int, len, CAAM_RNG_MAX_FIFO_STORE_SIZE);
+ len = CAAM_RNG_MAX_FIFO_STORE_SIZE;
dst_dma = dma_map_single(jrdev, dst, len, DMA_FROM_DEVICE);
if (dma_mapping_error(jrdev, dst_dma)) {
@@ -102,7 +101,7 @@ static int caam_rng_read_one(struct device *jrdev,
init_completion(done);
err = caam_jr_enqueue(jrdev,
- caam_init_desc(desc, dst_dma, len),
+ caam_init_desc(desc, dst_dma),
caam_rng_done, &jctx);
if (err == -EINPROGRESS) {
wait_for_completion(done);
@@ -122,7 +121,7 @@ static void caam_rng_fill_async(struct caam_rng_ctx *ctx)
sg_init_table(sg, ARRAY_SIZE(sg));
nents = kfifo_dma_in_prepare(&ctx->fifo, sg, ARRAY_SIZE(sg),
- CAAM_RNG_FIFO_LEN);
+ CAAM_RNG_MAX_FIFO_STORE_SIZE);
if (!nents)
return;
@@ -156,7 +155,7 @@ static int caam_read(struct hwrng *rng, void *dst, size_t max, bool wait)
}
out = kfifo_out(&ctx->fifo, dst, max);
- if (kfifo_len(&ctx->fifo) <= CAAM_RNG_FIFO_LEN / 2)
+ if (kfifo_is_empty(&ctx->fifo))
schedule_work(&ctx->worker);
return out;
@@ -186,7 +185,8 @@ static int caam_init(struct hwrng *rng)
if (!ctx->desc_async)
return -ENOMEM;
- if (kfifo_alloc(&ctx->fifo, CAAM_RNG_FIFO_LEN, GFP_DMA | GFP_KERNEL))
+ if (kfifo_alloc(&ctx->fifo, CAAM_RNG_MAX_FIFO_STORE_SIZE,
+ GFP_DMA | GFP_KERNEL))
return -ENOMEM;
INIT_WORK(&ctx->worker, caam_rng_worker);
--
2.21.0
next prev parent reply other threads:[~2020-03-16 15:01 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-16 15:00 [PATCH v8 0/8] enable CAAM's HWRNG as default Andrey Smirnov
2020-03-16 15:00 ` [PATCH v8 1/8] crypto: caam - allocate RNG instantiation descriptor with GFP_DMA Andrey Smirnov
2020-03-17 15:22 ` Horia Geantă
2020-03-16 15:00 ` [PATCH v8 2/8] crypto: caam - use struct hwrng's .init for initialization Andrey Smirnov
2020-03-16 15:00 ` [PATCH v8 3/8] crypto: caam - drop global context pointer and init_done Andrey Smirnov
2020-03-17 16:45 ` Horia Geantă
2020-03-19 13:00 ` Andrey Smirnov
2020-03-16 15:00 ` [PATCH v8 4/8] crypto: caam - simplify RNG implementation Andrey Smirnov
2020-03-17 21:37 ` Horia Geantă
2020-03-17 21:58 ` Horia Geantă
2020-03-19 13:07 ` Andrey Smirnov
2020-03-16 15:00 ` [PATCH v8 5/8] crypto: caam - check if RNG job failed Andrey Smirnov
2020-03-17 17:09 ` Horia Geantă
2020-03-16 15:00 ` [PATCH v8 6/8] crypto: caam - invalidate entropy register during RNG initialization Andrey Smirnov
2020-03-16 15:00 ` [PATCH v8 7/8] crypto: caam - enable prediction resistance in HRWNG Andrey Smirnov
2020-03-17 17:41 ` Horia Geantă
2020-03-17 17:59 ` Horia Geantă
2020-03-16 15:00 ` Andrey Smirnov [this message]
2020-03-17 21:56 ` [PATCH v8 8/8] crypto: caam - limit single JD RNG output to maximum of 16 bytes Horia Geantă
2020-03-17 11:16 ` [PATCH v8 0/8] enable CAAM's HWRNG as default Horia Geantă
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200316150047.30828-9-andrew.smirnov@gmail.com \
--to=andrew.smirnov@gmail.com \
--cc=cphealy@gmail.com \
--cc=herbert@gondor.apana.org.au \
--cc=horia.geanta@nxp.com \
--cc=iuliana.prodan@nxp.com \
--cc=l.stach@pengutronix.de \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-imx@nxp.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).