Re: [PATCH 2/4] DRBG: cleanup of preprocessor macros

From: Herbert Xu
Date: Fri Jul 04 2014 - 10:16:13 EST


On Sun, Jun 29, 2014 at 01:37:05PM +0200, Stephan Mueller wrote:
>
> When looking into the documentation and trying it I found:
>
> - bool choices allow me to only select one option, and only one
>
> - tristate choices allow me to only select one option, if the initial tristate
> is set to yes. If the initial tristate is set to module, it allows zero to all
> options to be set.
>
> That said, neither covers my requirement here: require that at least one
> option is set, but allow more options.

I have added the following patch to solve this problem.

Please respin your patch against this.

commit f2c89a10de4fd123a3d15223d26994f2fe1b95d8
Author: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Date: Fri Jul 4 22:15:08 2014 +0800

crypto: drbg - Use Kconfig to ensure at least one RNG option is set

This patch removes the build-time test that ensures at least one RNG
is set. Instead we will simply not build drbg if no options are set
through Kconfig.

This also fixes a typo in the name of the Kconfig option CRYTPO_DRBG
(should be CRYPTO_DRBG).

Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 1dca374..6345c47 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -23,7 +23,7 @@ comment "Crypto core or helper"

config CRYPTO_FIPS
bool "FIPS 200 compliance"
- depends on (CRYPTO_ANSI_CPRNG || CRYTPO_DRBG) && !CRYPTO_MANAGER_DISABLE_TESTS
+ depends on (CRYPTO_ANSI_CPRNG || CRYPTO_DRBG) && !CRYPTO_MANAGER_DISABLE_TESTS
depends on MODULE_SIG
help
This options enables the fips boot option which is
@@ -1394,39 +1394,39 @@ config CRYPTO_ANSI_CPRNG
ANSI X9.31 A.2.4. Note that this option must be enabled if
CRYPTO_FIPS is selected

-menuconfig CRYTPO_DRBG
+menuconfig CRYPTO_DRBG_MENU
tristate "NIST SP800-90A DRBG"
- depends on CRYPTO
- select CRYPTO_RNG
help
NIST SP800-90A compliant DRBG. In the following submenu, one or
more of the DRBG types must be selected.

-if CRYTPO_DRBG
+if CRYPTO_DRBG_MENU

config CRYPTO_DRBG_HMAC
bool "Enable HMAC DRBG"
default y
- depends on CRYTPO_DRBG
select CRYPTO_HMAC
help
Enable the HMAC DRBG variant as defined in NIST SP800-90A.

config CRYPTO_DRBG_HASH
bool "Enable Hash DRBG"
- depends on CRYTPO_DRBG
select CRYPTO_HASH
help
Enable the Hash DRBG variant as defined in NIST SP800-90A.

config CRYPTO_DRBG_CTR
bool "Enable CTR DRBG"
- depends on CRYTPO_DRBG
select CRYPTO_AES
help
Enable the CTR DRBG variant as defined in NIST SP800-90A.

-endif #CRYTPO_DRBG
+config CRYPTO_DRBG
+ tristate
+ default CRYPTO_DRBG_MENU if (CRYPTO_DRBG_HMAC || CRYPTO_DRBG_HASH || CRYPTO_DRBG_CTR)
+ select CRYPTO_RNG
+
+endif # if CRYPTO_DRBG_MENU

config CRYPTO_USER_API
tristate
diff --git a/crypto/Makefile b/crypto/Makefile
index bfa94fa..cfa57b3 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -92,7 +92,7 @@ obj-$(CONFIG_CRYPTO_842) += 842.o
obj-$(CONFIG_CRYPTO_RNG2) += rng.o
obj-$(CONFIG_CRYPTO_RNG2) += krng.o
obj-$(CONFIG_CRYPTO_ANSI_CPRNG) += ansi_cprng.o
-obj-$(CONFIG_CRYTPO_DRBG) += drbg.o
+obj-$(CONFIG_CRYPTO_DRBG) += drbg.o
obj-$(CONFIG_CRYPTO_TEST) += tcrypt.o
obj-$(CONFIG_CRYPTO_GHASH) += ghash-generic.o
obj-$(CONFIG_CRYPTO_USER_API) += af_alg.o
diff --git a/crypto/drbg.c b/crypto/drbg.c
index d6621a6..acc7523 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -99,12 +99,6 @@

#include <crypto/drbg.h>

-#if !defined(CONFIG_CRYPTO_DRBG_HASH) && \
- !defined(CONFIG_CRYPTO_DRBG_HMAC) && \
- !defined(CONFIG_CRYPTO_DRBG_CTR)
-#warning "The DRBG code is useless without compiling at least one DRBG type"
-#endif
-
/***************************************************************
* Backend cipher definitions available to DRBG
***************************************************************/

Thanks,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/