[PATCH] sctp: Make sha1 as default algorithm if fips is enabled

From: Ashwin Dayanand Kamat
Date: Tue Dec 20 2022 - 00:12:11 EST


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@xxxxxxxxxx>
---
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;

/* Max.Burst - 4 */
net->sctp.max_burst = SCTP_DEFAULT_MAX_BURST;
--
2.7.4