diff mbox series

sctp: Make sha1 as default algorithm if fips is enabled

Message ID 1671513037-8958-1-git-send-email-kashwindayan@vmware.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series sctp: Make sha1 as default algorithm if fips is enabled | expand

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netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/checkpatch warning WARNING: line length of 84 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Ashwin Dayanand Kamat Dec. 20, 2022, 5:10 a.m. UTC
MD5 is not FIPS compliant. But still md5 was used as the default algorithm
for sctp if fips was enabled.
Due to this, listen() system call in ltp tests was failing for sctp
in fips environment, with below error message.

[ 6397.892677] sctp: failed to load transform for md5: -2

Fix is to not assign md5 as default algorithm for sctp
if fips_enabled is true. Instead make sha1 as default algorithm.

Signed-off-by: Ashwin Dayanand Kamat <kashwindayan@vmware.com>
---
 net/sctp/protocol.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

Comments

Paolo Abeni Dec. 22, 2022, 9:22 a.m. UTC | #1
On Tue, 2022-12-20 at 10:40 +0530, Ashwin Dayanand Kamat wrote:
> MD5 is not FIPS compliant. But still md5 was used as the default algorithm
> for sctp if fips was enabled.
> Due to this, listen() system call in ltp tests was failing for sctp
> in fips environment, with below error message.
> 
> [ 6397.892677] sctp: failed to load transform for md5: -2
> 
> Fix is to not assign md5 as default algorithm for sctp
> if fips_enabled is true. Instead make sha1 as default algorithm.
> 
> Signed-off-by: Ashwin Dayanand Kamat <kashwindayan@vmware.com>

I don't know the fips standard in details, but it feel strange that you
get fips compliance _disabling_ the encryption. Can you please point
which part of the standard states it?

Since this is fix, you should also provide a suitable fixes tag. When
you will repost additionally include the target tree name (net) into
the subject, thanks!

> ---
>  net/sctp/protocol.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
> index 909a89a..b6e9810 100644
> --- a/net/sctp/protocol.c
> +++ b/net/sctp/protocol.c
> @@ -34,6 +34,7 @@
>  #include <linux/memblock.h>
>  #include <linux/highmem.h>
>  #include <linux/slab.h>
> +#include <linux/fips.h>
>  #include <net/net_namespace.h>
>  #include <net/protocol.h>
>  #include <net/ip.h>
> @@ -1321,14 +1322,13 @@ static int __net_init sctp_defaults_init(struct net *net)
>  	/* Whether Cookie Preservative is enabled(1) or not(0) */
>  	net->sctp.cookie_preserve_enable 	= 1;
>  
> -	/* Default sctp sockets to use md5 as their hmac alg */
> -#if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
> -	net->sctp.sctp_hmac_alg			= "md5";
> -#elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
> -	net->sctp.sctp_hmac_alg			= "sha1";
> -#else
> -	net->sctp.sctp_hmac_alg			= NULL;
> -#endif
> +	/* Default sctp sockets to use md5 as default only if fips is not enabled */
> +	if (!fips_enabled && IS_ENABLED(CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5))
> +		net->sctp.sctp_hmac_alg = "md5";
> +	else if (IS_ENABLED(CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1))
> +		net->sctp.sctp_hmac_alg = "sha1";
> +	else
> +		net->sctp.sctp_hmac_alg = NULL;

It looks like the listener can still fail if fips mode is enabled after
that the netns is initialized. I think it would be better to take
action in sctp_listen_start() and buming a ratelimited notice the
selected hmac is changed due to fips.

Thanks,

Paolo

>  
>  	/* Max.Burst		    - 4 */
>  	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
diff mbox series

Patch

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 909a89a..b6e9810 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -34,6 +34,7 @@ 
 #include <linux/memblock.h>
 #include <linux/highmem.h>
 #include <linux/slab.h>
+#include <linux/fips.h>
 #include <net/net_namespace.h>
 #include <net/protocol.h>
 #include <net/ip.h>
@@ -1321,14 +1322,13 @@  static int __net_init sctp_defaults_init(struct net *net)
 	/* Whether Cookie Preservative is enabled(1) or not(0) */
 	net->sctp.cookie_preserve_enable 	= 1;
 
-	/* Default sctp sockets to use md5 as their hmac alg */
-#if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
-	net->sctp.sctp_hmac_alg			= "md5";
-#elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
-	net->sctp.sctp_hmac_alg			= "sha1";
-#else
-	net->sctp.sctp_hmac_alg			= NULL;
-#endif
+	/* Default sctp sockets to use md5 as default only if fips is not enabled */
+	if (!fips_enabled && IS_ENABLED(CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5))
+		net->sctp.sctp_hmac_alg = "md5";
+	else if (IS_ENABLED(CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1))
+		net->sctp.sctp_hmac_alg = "sha1";
+	else
+		net->sctp.sctp_hmac_alg = NULL;
 
 	/* Max.Burst		    - 4 */
 	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;