2021-10-29 14:01:31

by Nicolas Toromanoff

Subject: [PATCH 3/8] crypto: stm32/cryp - fix CTR counter carry

Fix issue in CTR counter overflow, the carry-over is now properly
managed.
Fixes: bbb2832620ac ("crypto: stm32 - Fix sparse warnings")

Signed-off-by: Nicolas Toromanoff <[email protected]>
---
drivers/crypto/stm32/stm32-cryp.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/crypto/stm32/stm32-cryp.c b/drivers/crypto/stm32/stm32-cryp.c
index 7b55ad6d2f1a..6eeeca0d70ce 100644
--- a/drivers/crypto/stm32/stm32-cryp.c
+++ b/drivers/crypto/stm32/stm32-cryp.c
@@ -163,7 +163,7 @@ struct stm32_cryp {
struct scatter_walk in_walk;
struct scatter_walk out_walk;

- u32 last_ctr[4];
+ __be32 last_ctr[4];
u32 gcm_ctr;
};

@@ -1219,25 +1219,26 @@ static void stm32_cryp_check_ctr_counter(struct stm32_cryp *cryp)

if (unlikely(cryp->last_ctr[3] == 0xFFFFFFFF)) {
cryp->last_ctr[3] = 0;
- cryp->last_ctr[2]++;
+ cryp->last_ctr[2] = cpu_to_be32(be32_to_cpu(cryp->last_ctr[2]) + 1);
if (!cryp->last_ctr[2]) {
- cryp->last_ctr[1]++;
+ cryp->last_ctr[1] = cpu_to_be32(be32_to_cpu(cryp->last_ctr[1]) + 1);
if (!cryp->last_ctr[1])
- cryp->last_ctr[0]++;
+ cryp->last_ctr[0] = cpu_to_be32(be32_to_cpu(cryp->last_ctr[0]) + 1);
}

cr = stm32_cryp_read(cryp, CRYP_CR);
stm32_cryp_write(cryp, CRYP_CR, cr & ~CR_CRYPEN);

- stm32_cryp_hw_write_iv(cryp, (__be32 *)cryp->last_ctr);
+ stm32_cryp_hw_write_iv(cryp, cryp->last_ctr);

stm32_cryp_write(cryp, CRYP_CR, cr);
}

- cryp->last_ctr[0] = stm32_cryp_read(cryp, CRYP_IV0LR);
- cryp->last_ctr[1] = stm32_cryp_read(cryp, CRYP_IV0RR);
- cryp->last_ctr[2] = stm32_cryp_read(cryp, CRYP_IV1LR);
- cryp->last_ctr[3] = stm32_cryp_read(cryp, CRYP_IV1RR);
+ /* The IV registers are BE */
+ cryp->last_ctr[0] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV0LR));
+ cryp->last_ctr[1] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV0RR));
+ cryp->last_ctr[2] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV1LR));
+ cryp->last_ctr[3] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV1RR));
}

static bool stm32_cryp_irq_read_data(struct stm32_cryp *cryp)
--
2.17.1

2021-10-31 12:29:48

by Ard Biesheuvel

Subject: Re: [PATCH 3/8] crypto: stm32/cryp - fix CTR counter carry

On Fri, 29 Oct 2021 at 16:01, Nicolas Toromanoff
<[email protected]> wrote:
>
> Fix issue in CTR counter overflow, the carry-over is now properly
> managed.
> Fixes: bbb2832620ac ("crypto: stm32 - Fix sparse warnings")
>
> Signed-off-by: Nicolas Toromanoff <[email protected]>
> ---
> drivers/crypto/stm32/stm32-cryp.c | 19 ++++++++++---------
> 1 file changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/crypto/stm32/stm32-cryp.c b/drivers/crypto/stm32/stm32-cryp.c
> index 7b55ad6d2f1a..6eeeca0d70ce 100644
> --- a/drivers/crypto/stm32/stm32-cryp.c
> +++ b/drivers/crypto/stm32/stm32-cryp.c
> @@ -163,7 +163,7 @@ struct stm32_cryp {
> struct scatter_walk in_walk;
> struct scatter_walk out_walk;
>
> - u32 last_ctr[4];
> + __be32 last_ctr[4];
> u32 gcm_ctr;
> };
>
> @@ -1219,25 +1219,26 @@ static void stm32_cryp_check_ctr_counter(struct stm32_cryp *cryp)
>
> if (unlikely(cryp->last_ctr[3] == 0xFFFFFFFF)) {
> cryp->last_ctr[3] = 0;
> - cryp->last_ctr[2]++;
> + cryp->last_ctr[2] = cpu_to_be32(be32_to_cpu(cryp->last_ctr[2]) + 1);
> if (!cryp->last_ctr[2]) {
> - cryp->last_ctr[1]++;
> + cryp->last_ctr[1] = cpu_to_be32(be32_to_cpu(cryp->last_ctr[1]) + 1);
> if (!cryp->last_ctr[1])
> - cryp->last_ctr[0]++;
> + cryp->last_ctr[0] = cpu_to_be32(be32_to_cpu(cryp->last_ctr[0]) + 1);
> }
>

crypto_inc() ??

> cr = stm32_cryp_read(cryp, CRYP_CR);
> stm32_cryp_write(cryp, CRYP_CR, cr & ~CR_CRYPEN);
>
> - stm32_cryp_hw_write_iv(cryp, (__be32 *)cryp->last_ctr);
> + stm32_cryp_hw_write_iv(cryp, cryp->last_ctr);
>
> stm32_cryp_write(cryp, CRYP_CR, cr);
> }
>
> - cryp->last_ctr[0] = stm32_cryp_read(cryp, CRYP_IV0LR);
> - cryp->last_ctr[1] = stm32_cryp_read(cryp, CRYP_IV0RR);
> - cryp->last_ctr[2] = stm32_cryp_read(cryp, CRYP_IV1LR);
> - cryp->last_ctr[3] = stm32_cryp_read(cryp, CRYP_IV1RR);
> + /* The IV registers are BE */
> + cryp->last_ctr[0] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV0LR));
> + cryp->last_ctr[1] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV0RR));
> + cryp->last_ctr[2] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV1LR));
> + cryp->last_ctr[3] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV1RR));
> }
>
> static bool stm32_cryp_irq_read_data(struct stm32_cryp *cryp)
> --
> 2.17.1
>

2021-11-02 11:13:13

by Nicolas Toromanoff

Subject: Re: [PATCH 3/8] crypto: stm32/cryp - fix CTR counter carry

On Sun, 31 Oct 2021, Ard Biesheuvel wrote:

> On Fri, 29 Oct 2021 at 16:01, Nicolas Toromanoff
> <[email protected]> wrote:
>>
>> [...]
>>
>> @@ -1219,25 +1219,26 @@ static void stm32_cryp_check_ctr_counter(struct stm32_cryp *cryp)
>>
>> if (unlikely(cryp->last_ctr[3] == 0xFFFFFFFF)) {
>> cryp->last_ctr[3] = 0;
>> - cryp->last_ctr[2]++;
>> + cryp->last_ctr[2] = cpu_to_be32(be32_to_cpu(cryp->last_ctr[2]) + 1);
>> if (!cryp->last_ctr[2]) {
>> - cryp->last_ctr[1]++;
>> + cryp->last_ctr[1] = cpu_to_be32(be32_to_cpu(cryp->last_ctr[1]) + 1);
>> if (!cryp->last_ctr[1])
>> - cryp->last_ctr[0]++;
>> + cryp->last_ctr[0] = cpu_to_be32(be32_to_cpu(cryp->last_ctr[0]) + 1);
>> }
>>
>
> crypto_inc() ??

Good point, I didn't know/find this function.

Thanks,
Nicolas.