From:   Stephan =?ISO-8859-1?Q?M=FCller?= <smueller@chronox.de>
To:     herbert@gondor.apana.org.au
Cc:     linux-crypto@vger.kernel.org
Subject: [PATCH] crypto: RSA - limit key size to 2048 in FIPS mode
Date:   Sun, 21 Nov 2021 15:31:27 +0100
Message-ID: <25197881.1r3eYUQgxm@positron.chronox.de>
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Precedence: bulk

FIPS disallows RSA with keys < 2048 bits. Thus, the kernel should
consider the enforcement of this limit.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
---
 crypto/rsa.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/crypto/rsa.c b/crypto/rsa.c
index 4cdbec95d077..39e04176b04b 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -5,6 +5,7 @@
  * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
  */
 
+#include <linux/fips.h>
 #include <linux/module.h>
 #include <linux/mpi.h>
 #include <crypto/internal/rsa.h>
@@ -144,6 +145,9 @@ static int rsa_check_key_length(unsigned int len)
 	case 512:
 	case 1024:
 	case 1536:
+		if (fips_enabled)
+			return -EINVAL;
+		fallthrough;
 	case 2048:
 	case 3072:
 	case 4096:
-- 
2.33.1