Re: [PATCH] crypto/fips: only panic on bad/missing crypto mod signatures

[Herbert Xu]

On Fri, Jun 27, 2014 at 03:12:54PM -0400, Jarod Wilson wrote:
> Per further discussion with NIST, the requirements for FIPS state that
> we only need to panic the system on failed kernel module signature checks
> for crypto subsystem modules. This moves the fips-mode-only module
> signature check out of the generic module loading code, into the crypto
> subsystem, at points where we can catch both algorithm module loads and
> mode module loads. At the same time, make CONFIG_CRYPTO_FIPS dependent on
> CONFIG_MODULE_SIG, as this is entirely necessary for FIPS mode.
> 
> CC: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> CC: "David S. Miller" <davem@xxxxxxxxxxxxx>
> CC: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
> CC: Stephan Mueller <stephan.mueller@xxxxxxxxx>
> CC: linux-crypto@xxxxxxxxxxxxxxx
> Signed-off-by: Jarod Wilson <jarod@xxxxxxxxxx>
> ---
>  crypto/Kconfig  |  1 +
>  crypto/algapi.c | 13 +++++++++++++
>  kernel/module.c |  3 ---
>  3 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/crypto/Kconfig b/crypto/Kconfig
> index ce4012a..36402e5 100644
> --- a/crypto/Kconfig
> +++ b/crypto/Kconfig
> @@ -24,6 +24,7 @@ comment "Crypto core or helper"
>  config CRYPTO_FIPS
>  	bool "FIPS 200 compliance"
>  	depends on CRYPTO_ANSI_CPRNG && !CRYPTO_MANAGER_DISABLE_TESTS
> +	depends on MODULE_SIG
>  	help
>  	  This options enables the fips boot option which is
>  	  required if you want to system to operate in a FIPS 200
> diff --git a/crypto/algapi.c b/crypto/algapi.c
> index 7a1ae87..7d228ff 100644
> --- a/crypto/algapi.c
> +++ b/crypto/algapi.c
> @@ -43,6 +43,12 @@ static inline int crypto_set_driver_name(struct crypto_alg *alg)
>  
>  static int crypto_check_alg(struct crypto_alg *alg)
>  {
> +#ifdef CONFIG_CRYPTO_FIPS
> +	if (fips_enabled && alg->cra_module && !alg->cra_module->sig_ok)
> +		panic("Module %s signature verification failed in FIPS mode\n",
> +		      alg->cra_module->name);
> +#endif

Please hide the ugly ifdef in a helper inline function.

> @@ -437,6 +449,7 @@ int crypto_register_template(struct crypto_template *tmpl)
>  
>  	list_add(&tmpl->list, &crypto_template_list);
>  	crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
> +
>  	err = 0;
>  out:
>  	up_write(&crypto_alg_sem);

While I have no problems with you adding a blank line please don't
mix such additions with changes of substance.

Thanks,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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