Re: [PATCH] crypto: DRBG: do not call drbg_instantiate in healt test

[Tapas Sarangi <TSarangi@trustwave.com>]

Hi Stephan,

Thanks. The patch that I applied have different line numbers than yours.
In any case, patch worked to get rid of Œdrbg¹ related error.

Now, fips mode is failing on self-test:

/boot/vmlinuz-4.7.0-1.tos2_5: OK
[    1.296714] alg: skcipher: setkey failed on test 1 for xts(aes-asm):
flags=100000
[    1.297665] Kernel panic - not syncing: xts(aes): xts(aes) alg self
test failed in fips mode!
[    1.297665]




Thanks
-Tapas



On 8/9/16, 2:02 PM, "Stephan Mueller" <smueller@chronox.de> wrote:

>Am Dienstag, 9. August 2016, 19:52:46 CEST schrieb Stephan Mueller:
>
>Hi Tapas,
>
>I think I found the issue. Can you please test the attached patch?
>
>---8<---
>
>When calling the DRBG health test in FIPS mode, the Jitter RNG is not
>yet present in the kernel crypto API which will cause the instantiation
>to fail and thus the health test to fail.
>
>As the health tests cover the enforcement of various thresholds, invoke
>the functions that are supposed to enforce the thresholds directly.
>
>This patch also saves precious seed.
>
>Reported-by: Tapas Sarangi <TSarangi@trustwave.com>
>Signed-off-by: Stephan Mueller <smueller@chronox.de>
>---
> crypto/drbg.c | 15 ++++-----------
> 1 file changed, 4 insertions(+), 11 deletions(-)
>
>diff --git a/crypto/drbg.c b/crypto/drbg.c
>index f752da3..edf3ce0 100644
>--- a/crypto/drbg.c
>+++ b/crypto/drbg.c
>@@ -1917,6 +1917,8 @@ static inline int __init
>drbg_healthcheck_sanity(void)
>               return -ENOMEM;
>
>       mutex_init(&drbg->drbg_mutex);
>+      drbg->core = &drbg_cores[coreref];
>+      drbg->reseed_threshold = drbg_max_requests(drbg);
>
>       /*
>        * if the following tests fail, it is likely that there is a buffer
>@@ -1926,12 +1928,6 @@ static inline int __init
>drbg_healthcheck_sanity(void)
>        * grave bug.
>        */
>
>-      /* get a valid instance of DRBG for following tests */
>-      ret = drbg_instantiate(drbg, NULL, coreref, pr);
>-      if (ret) {
>-              rc = ret;
>-              goto outbuf;
>-      }
>       max_addtllen = drbg_max_addtl(drbg);
>       max_request_bytes = drbg_max_request_bytes(drbg);
>       drbg_string_fill(&addtl, buf, max_addtllen + 1);
>@@ -1941,10 +1937,9 @@ static inline int __init
>drbg_healthcheck_sanity(void)
>       /* overflow max_bits */
>       len = drbg_generate(drbg, buf, (max_request_bytes + 1), NULL);
>       BUG_ON(0 < len);
>-      drbg_uninstantiate(drbg);
>
>       /* overflow max addtllen with personalization string */
>-      ret = drbg_instantiate(drbg, &addtl, coreref, pr);
>+      ret = drbg_seed(drbg, &addtl, false);
>       BUG_ON(0 == ret);
>       /* all tests passed */
>       rc = 0;
>@@ -1952,9 +1947,7 @@ static inline int __init
>drbg_healthcheck_sanity(void)
>       pr_devel("DRBG: Sanity tests for failure code paths successfully "
>                "completed\n");
>
>-      drbg_uninstantiate(drbg);
>-outbuf:
>-      kzfree(drbg);
>+      kfree(drbg);
>       return rc;
> }
>
>--
>2.7.4
>
>


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