module: Do not offer sha224 for built-in module signing

[PATCH] module: Do not offer sha224 for built-in module signing

Posted by Dimitri John Ledkov 2 years, 2 months ago

sha224 does not provide enough security against collision attacks
relative to the default keys used for signing (RSA 4k & P-384). Also
sha224 never became popular, as sha256 got widely adopter ahead of
sha224 being introduced.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
---
 kernel/module/Kconfig | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index 19a53d5e77..9d7d45525f 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -236,10 +236,6 @@ choice
 	  possible to load a signed module containing the algorithm to check
 	  the signature on that module.
 
-config MODULE_SIG_SHA224
-	bool "Sign modules with SHA-224"
-	select CRYPTO_SHA256
-
 config MODULE_SIG_SHA256
 	bool "Sign modules with SHA-256"
 	select CRYPTO_SHA256
@@ -257,7 +253,6 @@ endchoice
 config MODULE_SIG_HASH
 	string
 	depends on MODULE_SIG || IMA_APPRAISE_MODSIG
-	default "sha224" if MODULE_SIG_SHA224
 	default "sha256" if MODULE_SIG_SHA256
 	default "sha384" if MODULE_SIG_SHA384
 	default "sha512" if MODULE_SIG_SHA512
-- 
2.34.1

Re: [PATCH] module: Do not offer sha224 for built-in module signing

Posted by Herbert Xu 2 years, 2 months ago

On Tue, Oct 10, 2023 at 10:26:33PM +0100, Dimitri John Ledkov wrote:
> sha224 does not provide enough security against collision attacks
> relative to the default keys used for signing (RSA 4k & P-384). Also
> sha224 never became popular, as sha256 got widely adopter ahead of
> sha224 being introduced.
> 
> Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
> ---
>  kernel/module/Kconfig | 5 -----
>  1 file changed, 5 deletions(-)

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